Organizer:Ministry of Education

Governing Body:Sichuan University

Editor in chief:WANG Yu-Zhong

The standing deputy editor:ZOU Fang-Dong

ISSN:51-1595/N

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Journal of Sichuan University
(Natural Science Edition)

(natural science edition) editorial board

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    Mathematics
    • A load-balanced TTE scheduling method for large-scale messages transmission

      Ye Fan, Chen Yin-Chao, Wang Tao, Ji Yuan-Dong, Luo Mao-Kang, Jiang Xiu-Qiang

      2022,59(4):041001

      Abstract:

      There are ungent requirements of large-scale messages transmission in the airborne networks with complex topologies. When the triditional Time-triggered Ethernet ( TTE ) scheduling methods are used to meet a requirement, the time complexity is very high. To solve this problem, we in this paper propose a new TTE message scheduling method based on the idea of load balancing. In this method, a set of candidate paths is firstly generated and then selected according to the message length and the data flow link load. Those paths with load balancing characteristics are choosen. Then the messages are scheduled based on static priority, sorted according to message length and cycle, and allocated by using the " back to back " rule. Finally, the method is compared to the triditional Satisfiablity Modulo Theory (SMT) method to illustrate its performance. Simulation results show that, while the method can reduce the computation time by more than 90% when the schedulable message frames are more than 6000, the computational efficiency is improved by 10~100 times on the basis of ensuring the real-time performance of the message. Therefore, the method is suitable for complex large-scale data scheduling table generation and can feasibly improve the message scheduling performance of airborne network.

    • An iterative solver for time-periodic heat optimal control problems

      Li Ke, Guo Da-Li, Zhao Yun-Xiang

      2022,59(4):041002

      Abstract:

      In this paper, an iterative algorithm is introduced for solving a class of optimal control problems constrained by time-periodic heat equation, where the optimization is concerned by searching a best source term of the heat equation to minimize the objective function. By applying the optimality condition, the problem is firstly transformed into two coupled time-period heat equations. Then iterative algorithm is applied to decouple the PDE system. Finally, the equations are separately solved in the Gauss-Seidel pattern. Numerical examples are presented to illustrate the robustness of convergence rate of the algorithm with respect to the discretization parameters.

    • Crossing limit cycles of a 3D piecewise-smooth system

      ZHENG Ying-Ying, CHEN Xing-Wu

      2022,59(4):041004

      Abstract:

      In this paper we investigate the crossing limit cycles of a 3D discontinuous piecewise-smooth system. In this system, the phase space is divided into two regions by a hypersurface and thus the system presents two different vector fields. Meanwhile, the system presents two-fold in which both vector fields are tangent to the hypersurface. We prove that the maximum number of crossing limit cycles is 2 and give necessary and sufficient conditions for one and two crossing limit cycles respectively. Furthermore, the crossing locations of crossing limit cycles are all determined as well as their periods.

    Computer Science
    • Research on optimized modelling and algorithm of integrated allocation of irregular berth and quay crane

      ZHAO Jiao, HU Hui, YUAN Hua-Zhi

      2022,59(4):042001

      Abstract:

      As the limited resources of the port, the optimal allocation of berths and quay cranes is conducive to improve the operation efficiency of the port and speed up the departure time of ships. Due to the limitation of geographical conditions, the berth lines of some ports are not linear, but show "L" or "F" shape, such as quay cranes can not free to move on these discontinuous berth, this kind of berth allocation problem cannot be optimized based on the continuous berth allocation problem, and the space of the berth line will be wasted based on the discrete berth allocation problem. For the irregular berths and quay crane integrated distribution problem, according to the relative location and time of arrived ships, a mixed linear programming mathematics models is established, three valid inequalities are extracted by analyzing the features and variable relationship, and CPLEX software is used to solve the model. With the increasing of the problem size, the solving time is increasing. Therefore, the improved particle swarm algorithm is proposed, a new velocity updating formula with random search strategy is used to avoid falling into local optimum. The experiment results show that the average solving time is reduced by 83.23% by adding the valid inequalities. The average result obtained by the improved particle swarm algorithm is reduced by 25.21% than that of the standard particle swarm algorithm. It is proved that the improved particle swarm optimization algorithm proposed in this paper is effective in solving the problem of irregular berth and quay crane allocation.

    • New adaptive median denoising model combined with cyclic iterative method

      XU Li, HOU Jie, CHEN Qing-Li, QIN Ya-Qi, PENG Yi-Cui, HUANG Guo

      2022,59(4):042002

      Abstract:

      Aiming at the disadvantage of traditional salt-and-pepper noise removal methods that the denoising performance is poor when the image noise density is high, a new adaptive median denoising model combined with cyclic iterative method is proposed, in order to improve the performance of denoising algorithm in high-density salt and pepper removal. The working mode of the proposed filter can be divided into three stages. First, the image is preprocessed, that is, the suspected noise points are obtained from the pixels to be processed using the extreme value judgment method. Secondly, the noise points are determined and replaced adaptively by the median or mean value in the neighborhood to complete the denoising. Finally, the suspected noise points are processed again, and whether the suspected noise points are noise points is further judged by the algorithm with built-in parameters and conditions. The noise mark point method is also induced, and the filtered image is obtained by finding the end of mark point denoising through iterative processing. The results of simulation experiments show that the proposed method has a certain improvement in denoising performance for both low-density noise images and high-density noise images, compared with several traditional salt-and-pepper noise removal filtering algorithms.

    • 3D-2D mapping based large-pose face recognition

      LI Xiao-Feng, YOU Zhi-Sheng

      2022,59(4):042003

      Abstract:

      To solve the problem of low accuracy of large pose face recognition in real scenes, a large pose face recognition algorithm framework is proposed based on the 3D-2D mapping focusing on the exploration of the key technologies of large pose face recognition from the perspective of data augmentation. Different from the current face recognition algorithm based on 3D point cloud data, the proposed method mainly uses 3D face data to enrich the posture information via the data expansion method by 3D-2D mapping. The specific posture face feature extraction models are trained and integrated into the unified large pose face recognition framework. The key of the proposed method is to use registered 3D face information to assist 2D face multi-pose recognition. It is easy to integrate existing 2D face recognition methods into the proposed framework. Experiments show that the method proposed in this paper can effectively improve the accuracy of large pose face recognition in unconstrained real scenes without increasing the significant computational load and provides a new idea for the current 3D information to solve the 2D face recognition problem.

    Electronics and Information Science
    • Research on PID parameters optimization of heat sealing knife temperature control system based on improved SA-WOA algorithm

      WEI Shang-Yun, MA Jing, HU Xiao-Bing, LI Hu, GUO Shuang, ZHANG Cheng-Jun

      2022,59(4):043001

      Abstract:

      The temperature of the heat-sealing knife of the bagging machine is usually controlled by PID algorithm, but the control effect is not so good since the PID control parameters are mostly set by human experience. To solve this problem, an improved SA-WOA algorithm is proposed to realize the self-tuning of PID control parameters. First, the step response curve method is used to establish the transfer function model of the system, and then the advantages of the whale algorithm and the simulated annealing algorithm are considered, and the two are combined. On this basis, the algorithm is improved to improve the convergence speed and optimization effect of the algorithm. The improved algorithm is simulated and compared on the MATLAB R2017b platform. Finally, the control parameters obtained from the simulation are tested on the bagging machine. The simulation comparison results show that the parameter control effect obtained by the algorithm optimization in this paper is better compared with the relay feedback algorithm, the particle swarm algorithm and the improved particle swarm algorithm based on simulated annealing. The actual test results show that the parameter control effect obtained by the algorithm in this paper is good and can meet the actual demand.

    • PSD and light source modulation based cooperative target pose detection method

      CHENG Shao-Wei, LIU Jin, ZHANG Peng-Cheng, YANG Hai-Ma, ZHAO Hong-Zhuang, YUAN Xue-Qi

      2022,59(4):043002

      Abstract:

      The relative position and attitude detection of space targets is the focus of research in the field of spacecraft docking, and the detection methods are mainly divided into two categories: telemetry and optical measurement methods. Among them, the latter has become the main method for close-range position and attitude detection relying on its advantages of high speed, high stability and large amount of information. The depth information of the characteristic light points on the spatially cooperative target can be calculated using the binocular vision model, and the target attitude can be obtained based on the known structure, size and other constraint information among the characteristic light points. The PSD has the advantages of having no image feature extraction process, responding fast and having high resolution for positions, compared with CCD and CMOS sensors, and the bionic structure of binocular stereo vision system can help directly obtain the depth information of the detection target. Therefore, this paper proposes a dual PSD vision model with joint modulation of luminance and order of feature light points to achieve the positional detection method of spatial cooperative targets. The experimental results show that the average measurement error of the system is 2.541° when the attitude of the cursor target is adjusted ±30°. The average deviation of the pitch angle and yaw angle are 0.923° and 0.563° when the attitude angle is less than 15°. The average deviation of the pitch angle and yaw angle increase to 4.566° and 4.106° when the attitude angle is larger than 15°, restricted by the divergent angle of the light source; the system can quickly and stably solve the spatial attitude of the cursor target.

    • Research on numerical simulation method of human-vehicle interaction behavior based on cellular automata

      ZHAI Yue, WANG Ru-Hao, QU Lu, BO-Jie, ZHAO Rui-Feng, DU Jing

      2022,59(4):043003

      Abstract:

      In order to improve the rationality of the mixed evacuation simulation of pedestrians and vehicles in complex human-vehicle interaction scenarios, reliable technical support is provided for safe design and efficient operation in such scenarios. Based on the cellular automata model, this paper constructs and develops a pedestrian-vehicle mixed-flow interaction model that takes into account factors such as pedestrians crossing obstacles, vehicles avoiding pedestrians, and vehicle parking on whether pedestrians pass the road or not. This method is used to simulate a typical commercial underground parking lot in Xi'an, and the relationship between the microscopic human-vehicle interaction behavior and evacuation time and safety accidents in the evacuation process in this scene is studied. The conclusion shows that the simulation method constructed in this paper sets independent behavior rules for pedestrians and vehicles and performs nonlinear coupling simulations, which is more in line with the real scene; the simulation results of the scene can be obtained, within the carrying capacity of the lane, the vehicle and the parking space in the lane The influence of interaction is the main factor that causes delays and dangerous situations in the process of mixed traffic between people and vehicles.

    Physics
    • Photon characteristic line hybrid pencil beam model for lung phantoms under condition of small fields

      CUI Feng-Jie, WANG Ning-Yu, GU Shao-Xian, YANG Peng, YIN Chu-Ou, ZHANG Sheng-Yuan, HU Jin-You, CAI Yun-Zhu, WU Zhang-Wen, WANG Jun, GOU Cheng-Jun

      2022,59(4):044001

      Abstract:

      In order to accurately calculate the three-dimensional dose distribution in a lung phantom photon under a small fied, photon characteristic line hybrid pencil beam model has been proposed. The model is based on the photon characteristic line algorithm to obtain the depth dose for lung phantoms in the reference field. On this basis, the pencil beam kernel of lung phantom is processed by heterogeneous correction, including equivalent depth correction and weighted density correction. Finally, the pencil beam kernel for lung phantom is calculated for obtaining the dose at each point on the central axis for the 6 MV photon beam. The results show that the central axis percentage depth dose obtained by this algorithm is basically consistent with the Monte Carlo simulation results, and the relative error is less than 3% in most cases. Especially in the middle and posterior portion of lung, the average relative error is less than 1%. However, the dose difference between the two methods is obvious at media interfaces and lung anterior portion, and the relative errors decrease with the increase of field size and lung density, with the maximum relative error ranging from 7.8% to 36.9%. Nevertheless, the model can accurately describe the dose distribution in small fields for lung radiotherapy.

    • Stochastic resonance based on asymmetric bistable systems and its applications

      CHEN Yang, ZHANG Jian-Gang

      2022,59(4):044002

      Abstract:

      The signal-to-noise ratio and mean first passage time of asymmetric bistable stochastic resonance (ABSR) system driven by Gaussian colored noise are studied. Based on the unified color noise approximation and two-state model theory, the formulas of mean first passage time and signal-to-noise ratio are derived. The influence of various parameters on signal-to-noise ratio and mean first passage time are discussed, and the parameters are optimized. It is found that stochastic resonance is a non-monotonic function of noise intensity and potential well asymmetry, and the same parameter has different effects on the mean first passage time in two different directions. Simulation and experiment prove that ABSR system has obvious advantages in bearing fault diagnosis.

    • Density functional theory study on X-doped Bn+1 clusters (n=1~11; X=Be,Mn)

      WANG Bi-Li, CHEN Xuan, SONG Rui, QIN Meng

      2022,59(4):044004

      Abstract:

      The ground state structures, stabilities, electronic configurations and magnetic properties of Bn X clusters(n=1~11; X=B, Be, Mn) have been systematically investigated by density functional theory. The results show that the X atoms are all located with high coordination number in BnX clusters (n=5-11; X=Be, Mn) , The lowest energy structures of BnBe are low spin multiplicity states with multiplicities of 1 or 2. The average binding energies of BnX clusters are increasing with increased size. When n is the same, the cluster Bn+1 has the highest average binding energy. The energy gaps of BnX clusters indicate that the stability of Bn+1 is increased by X-doping (X=Be, Mn). The Be atom is the acceptor of charges in BnBe clusters. The orbital electrons of Mn atoms in BnMn clusters exhibit significant spd hybridization. The magnetic moments of BnX clusters (X = B, Be) with open-shell structures are mainly contributed by 2p orbitals. The electronic structures of BnMn clusters are all Open shell , and the magnetic moment are mainly contributed by Mn3d orbitals. The coordination number of Mn atoms and the average bond lengths of B-Mn increased with size increasing. Accordingly the magnetic moment of BnMn clusters decreased by the reduction of Mn3d orbital magnetic moment.

    Chemistry and Material Science
    • Adsorption of polyvinylpyrrolidone on Ag surface and mechanism of selective growth of Ag nanostructures

      LIU Bo, SUN Hong-Juan, PENG Tong-Jiang, HE Rong, ZHU Wen-Kun

      2022,59(4):045001

      Abstract:

      To elucidate the mechanism of selective growth of Ag nanowires in capping agents, we investigated and the interaction between polyvinylpyrrolidone (PVP) molecules and various Ag crystal surfaces by first-principles calculations. The results show that PVP molecules severely affect the stability of Ag surfaces. Only Ag (200) and Ag (111) facets well maintain their structures upon the absorption of PVP molecules, suggesting their preferential growth in this capping agent. With the increase of PVP concentration, the binding of PVP molecules to the Ag (200) facet becomes stronger than that of Ag (111), which may facilitate the formation of Ag (200) nanostructure. The regulation mechanism of long-chain PVP molecules on Ag (200) nanostructures is mainly governed by the van der Waals force as well as the chemical bonding between ketone oxygen and Ag atoms.

    • Preparation and properties of Ymer N120 modified non-ionic waterborne epoxy emulsion

      SUN Shi-Xiong, CHEN Ya-Jun, ZHANG Ming-Hui, ZHAO Ben-Bo, DENG Ping, CHENG Yuan

      2022,59(4):045002

      Abstract:

      In order to overcome the disadvantage of low content of epoxy group and solid in current waterborne epoxy (WEP) emulsion, polyethylene glycol 400 (PEG400) was used as soft section to prepare non-ionec WEP emulsion firstly. Then, the modified non-ionic waterborne epoxy (YWEP) emulsion was synthesized with the side hydrophilic chain extender (Ymer N120). The effects of the dosage of Ymer N120 on the properties of YWEP emulsion and paint film were studied. The results showed that the epoxy group content (represented by epoxy value) of the WEP emulsion could be increased as high as 0.36, and the solid content pof YWEP emulsion increased by 73.3% from 30% to 52% while maintaining the high expoxy value. After curing, the tensile strength of the film increases from 57.3 MPa to 64.8 MPa. The corrosion current density decreased from7.97E-8 mA*cm-2 to 9.99E-9 mA*cm-2. In conclusion, the transfer of hydrophilic groups from the main chain to the side group can effectively improve the properties of waterborne epoxy emulsions, coatings and coatings.

    • 3D printing of shape-controllable alumina ceramics by using optimized slurry and sintering process

      CHEN Long, WANG Zheng-Shang, CUI Xu-Dong

      2022,59(4):045003

      Abstract:

      In this work, the relationship between solid content and viscosity for light curing slurry was studied. The preparation and printing of high solid content slurry (45 vol%) were realized by regulating rheological priperties of the dispersant. It is found that the processes of degreasing and sintering are key factors and cracks, which directly affect the quality of ceramics. Thus, the degreasing curve was adjusted according to the type of organic matter in the prepared alumina ceramic slurry. In addition, the two-step degreasing methods of pyrolysis in vacuum and carbon removal in air can fully remove the organic mater, which is not easy to peroduce pores. Finally, the alumina ceramic material with the dense structure was obtained. In all, the effects of dispersant type, concentration and alumina solid content on slurry viscosity were systematically analyzed and the degreasing process was optimized. We hope our work can provied an experimental basis for the light curing molding and the perormance optimization of complex structural ceramic materials.

    Biology
    • Genome-wide analysis of TPS gene family of Zanthoxylum armatum

      REN Miao-Zhen, DONG Kai-Lin, ZHANG Jian, CHEN Zhi-Duan, SU Jun-Xia

      2022,59(4):046001

      Abstract:

      In order to explore the potential function of the TPS gene family in perfume plant, a comprehensive investigation of the TPS gene family was conducted in the well-known perfume plant Zanthoxylum armatum, and the basic physical and chemical properties, gene duplication type, subcellular localization, evolutionary relationship, chromosome localization and collinear analysis, gene structure and gene expression pattern were analyzed. A total of 53 ZaTPS genes were identified in the whole genome of Z. armatum. The amino acid length of their proteins ranges from 173 to 859 aa, and the molecular weight ranges from 20.21 to 98.44 kDa. The isoelectric point ranges from 4.87 to 9.10, and the subcellular localizations are mainly in the cytoplasm and chloroplast. Phylogenetic analysis showed that ZaTPSs could be divided into six subfamilies, and the members of TPS-a and TPS-b subfamilies were the majority ones. There are 48 ZaTPSs containing motif1 that are conserved in the TPS proteins. Chromosomal localization and collinear analysis showed that 53 ZaTPSs were unevenly distributed on 11 chromosomes, and there were four pairs of tandem repeats, and the collinear analysis revealed that TPS genes in Z. armatum and Citrus sinensis from the same family have closer evolutionary relationships. The gene differential expression analysis based on transcriptome datasets showed that ZaTPSs had tissue specific expression patterns, with the highest expression level was found in young flowers, followed by husks. These results indicate that ZaTPSs played an important role in the synthesis of husks volatile oil and defense.

    • Isolation, identification, serotyping and pathogenicity of Salmonella from Yaks in Tibet

      LI Tian-Jiao, BANMA Ze-Lang, ZHANG Kai-Qin, ZHAO Xiao-Hui, WANG Bao-Ning, SUOLANG Si-Zhu

      2022,59(4):046002

      Abstract:

      The purpose of this study was to understand the prevalence, distribution and serotypes of Salmonella from yak sources in Tibet. By collecting yak diarrhea feces in seven districts of Tibet, the bacteria in the samples were isolated and identified by using bacterial culture, biochemical characteristics, and molecular biology methods, and then the isolated strains were serotyped according to serum specific agglutination, and finally, animal infection and HE staining of animal tissue were used to understand the pathogenicity of strains. The results showed that a total of 50 Salmonella strains were isolated from the whole region of Tibet, with a detection rate of 25.13% (50/199). Among them, the separation rate of Lhasa, Qamdo, and Shannan was higher than the other four, and the Ngari area is the lowest; the serotyping results show that 4 serogroups including B group, C1 group, C2 group and D group were isolated. The serogroup includes 18 serotypes including Salmonella Dublin, Salmonella Typhi, and Salmonella Aboni. According to serogroup statistics, among the 4 serogroups, group D accounts for the most serogroups and is a common serogroup; 50 Salmonella strains were dominated by Salmonella, accounting for 20.00% (10/50 ) of all strains; The typing results of Salmonella in various regions show that the number of serogroups and serotypes in each region are different. The results of the pathogenicity test showed that the LD50 of KM mice infected with yak-derived S.dublin was 0.368×108CFU/mL, which was a highly lethal strain. The results of tissue HE staining showed that yak-derived S.dublin could cause systemic damage to the host. Among them, the spleen, lung, intestine and stomach have more severe lesions. The results of this experiment suggest that Salmonella does exist in Tibetan Yak sources, and has a certain trend of prevalence. At the same time, the common serogroups, dominant serotypes and dominant serotypes of Salmonella dublin from yak sources in Tibet have been identified, and the pathogenicity of the dominant serotype was also identified.

    • Wholegenome identification and expression analysis of actin gene family in Chara braunii

      HU Sha-Sha, ZHANG Dong-Qun, ZHANG Yi-Peng, HAN Peng-Ju, LAN Li-Qiong, QING Ren-Wei

      2022,59(4):046003

      Abstract:

      In order to understand the potential functions of actin in the growth and development of Charophytes, bioinformatics methods were used to analyze the actin gene family in Chara braunii. A total of 16 actin genes were identified in Chara braunii, and they were renamed as CbACT1~CbACT16 according to their order on scaffolds with 361 to 1182 amino acids, and the relative molecular masses ranged form 39 886.71 to 117 256.72 Da, and protein isoelectric point was range from 4.68 to 8.93. Subcellular localization prediction indicated that 15 actin genes were located in the cytoplasm; and only one in the chloroplast. The secondary structure of the actin gene was mainly composed of random coils and α-helices. Only one pair of paralogous genes derived from segmental duplication was found in the collinearity analysis. The phylogenetic results divided actin genes into two subfamilies with the same subfamily tend to have similar exon distribution and more common motifs. Promoter cis-element analysis indicated that 16 actin genes were involved in many biological activities including biotic and abiotic stresses, hormone regulation and light response. Further tissue expression analysis suggested that 16 genes were differentially expressed in four different tissues, indicating that they have different functions in the growth and development of different tissues. Therefore, the actin gene family may be involved in the development of different tissues and response to biotic and abiotic stresses of Charophytes.

    • Analysis of the interaction modes of Jatropha curcas ribosome inactivating proteins Curcin and Curcin C with adenosine and adenine

      DENG Yu-Shan, XU Ying

      2022,59(4):046004

      Abstract:

      Jatropha curcas ribosome-inactivating proteins Curcin and Curcin C have N-glycosidase activity, but their in vitro translation inhibition ability is significantly different, which implies that there are also differences in the N-glycosidase activity of the two proteins. In order to explore the structural basis for this difference, this study used trRosetta to predict the tertiary structure of the two proteins, and evaluates the quality of the predicted tertiary structure model through PROCHECK and Qmean.The structure of adenine and adenosine was optimized by Chem3D, and the amino acid composition of Curcin and Curcin C active site was predicted by UCSF Chimera.Finally, AutoDock was used for molecular docking to predict the interaction of two protein model with adenine and adenosine. The docking results showed that the interaction modes between the two proteins and adenine were similar, but the key amino acid Arg of Curcin did not participate in the interaction with the ligand. In addition, the binding energy of Curcin C to adenine and adenosine is lower than that of Curcin, and the difference between the binding energy of Curcin C to adenosine and adenine is also higher than that of Curcin.This result implies that the difference in activity between Curcin and Curcin C is related to the structural features at the active site, and the key amino acid Arg in Curcin C is closer to the binding sites of adenine and adenosine.This will lead to lower binding energy between Curcin C and the substrate, which is more conducive to the catalytic reaction.

    Computer Science
    • Radar target tracking algorithm based on adaptive DBSCAN

      ZHANG Qiao, YANG Hong-Yu, LIU Hong, LIU Yu, YAN Zhen

      2021,58(1):012001

      Abstract:

      Directly processing the track initiation and tracking of the points recorded in the radar point recorder of the three dimensional air traffic control system will generate a large number of false alarms and a large amount of calculation. When performing target tracking, the number of candidate point sets is huge is the main reason for the large amount of calculation in the target tracking process. Based on the dynamic adaptive DBSCAN clustering algorithm and the classic Kalman filter tracking algorithm, a hybrid dynamic adaptive DBSCAN clustering tracking algorithm is proposed in this paper to reduce the number of candidate point sets. Experiments have found that the number of invalid points is reduced and the track quality is improved Computing time decreases. Through the dynamic adaptive DBSCAN clustering tracking hybrid algorithm, it can quickly track the target detected by cnac radar once and form the target track, which can detect the black flight target in time and reduce the interference to the normal flight of civil aviation aircraft to the minimum.

    • Image enhancement new model based on rational-order Partial Differential

      jiangwei, 李小龙, 刘亚威

      2016,53(1):47-53

      Abstract:

      In order to sharpen the image edge features while enhancing texture detail, the image enhancement model based on space rational-order derivative was constructed by the effective combination of integer-order theory and fractional-order calculus theory to derive the differential expression of rational-order partial differential, and the numerical of enhanced model was achieved using rational-order partial differential mask operator. The experimental results showed that compared with the fractional-order differential method , the image enhancement model can be obtained the effect of continuous variation, that not only enhanced image texture well, but also improved the edge enhancement effect. Objectively, using image edge evaluation parameters of texture features such as information entropy and average gradient for quantitative analysis and experimental verification shown that the new model combined the advantages of integer and fractional order differential to make up for their lack of own and achieved a good image enhancement results.

    • Automatically generating visually pleasing Information Walls

      CHEN Rui, XIE Ying-Tao, HUA Li-Xian, CHEN Yu, LIN Tao

      2016,53(1):61-66

      Abstract:

      Information Wall (IW) is a GUI composed of rectangular cells each contains various kinds of information. The design and implementation of IW are mainly in a manual way nowadays, which typically leads to less variability in appearance style and low efficiency. This paper develops a tool to automate the generation of text-IWs based on a genetic programming algorithm. A model, which evaluates the visual quality of text-IWs, is also proposed and incorporated in the algorithm to make generated IWs more visually pleasing. Test results show that the tool is able to efficiently produce good looking IWs with variable appearance styles. With the help of the tool, designer productivity could be improved by utilizing machine-generated prototypes.

    • Research of Internal Image Move-Copy Tampering Forensics Algorithm

      LI Ruo-Chen, JU Shen-Gen, ZHOU Gang, SHAO Shou-Ping

      2016,53(1):67-72

      Abstract:

      According to the low robustness characteristics of image tampering with evidence of general move-copy algorithm, this paper proposes a new algorithm. Firstly, it uses the color invariant feature to detect feature points, which improves recall forensic results. Secondly, it uses the RGB color channel to expansion Surf descriptor, which increases the robustness of feature vectors. Then, it defines noise sensitivity coefficients to identify and deal with the image noise points and use sequential similarity detection algorithm to improve feature points registration. Finally, it uses Kendall coefficient and the four hypothesis to constrain the forensic results and get the final result. Experimental results show that the new algorithm reflects higher accuracy and strong robustness and it has strong ability of forensics.

    • Research on Encryption of Digital Image Based on Improper Fractional-order Laser Chaos

      ZHAO Jian-Feng, WANG Shu-Ying, Li Xian-Feng, Zhang Li-Tao

      2016,53(1):79-86

      Abstract:

      To improve the safety of information encryption, based on an improper fractional-order laser chaos, a digital image encryption algorithm is proposed. The key space is formed by initial state variables, parameters and orders of the system. Every pixel value is included in secret key, so as to improve anti-attack capability of the algorithm. Lena gray image and Couple color image are encrypted in numerical simulation. Theoretical analysis and simulation results show that this algorithm with a sufficiently large key space not only can perfectly resist the ciphertext attack and differential attack, but also is excellent against chosen plaintext attack and statistical attack, which can be used in secure communication of multimedia data.

    • Topology analysis of Chinese airspace domestic flights

      WU Ke, WANG Jun-Feng, LUO Qin

      2016,53(1):73-78

      Abstract:

      The research of ad-hoc network based on Chinese airspace flight topology will help to meet the needs of future flights on aspects of air traffic control and information sharing,but the existing studies has not analysis the flights topology according to the specific condition of Chinese airspace. This paper collects real Chinese airspace domestic flights data and divides the Chinese airspace into east part,west part, and flight information region with NS2 simulation,and compares Chinese airspace flight topology within one day and 24 hours. The results showed that the distributions of Chinese domestic flights have big differences with each other in the Chinese airspace,however,the number of the flights shows a relative high linear correlation with the population and the third output.

    • Basic elements of brain-like computing: From memristor to fracmemristor

      PU Yi-Fei, YU Bo, YUAN Xiao

      2020,57(1):49-58

      Abstract:

      In this paper, fractional-order memristor (fracmemristor), a novel basic element of brain-like computing, is discussed.The concept of memristor is extended from the conventional integer order to the fractional order, i.e. the fracmemristor. Fracmemristor is a compound word of fractional-order memristor, whose fractional impedance is fracmemristance. Accordingly, it is natural to think of a range of theoretical challenges: What is the relationship of fracmemristor to the conventional fractor and the famous memristor? What are the interpolation properties between the memristor and the capacitor or inductor? Where is the location of fracmemristor in the Chua's circuit periodic table? What are the general expressions for fracmemristances of arbitrary-order ideal capacitive and inductive fracmemristors? What are the measuring unit and physical dimensionality of fracmemristor? What are the fingerprint features for identifying fracmemristor? How to implement arbitrary fractional-order memristor effectively in the form of analog circuit with ordinary memristor, capacitor and inductor? This paper makes preliminary discussions on the above challenging theoretical problems based on abundant prior exploratory findings. The fracmemristor solves the problem that fractor is difficult to realize the function of memory charge or magnetic flux. As a basic circuit element, the fracmemristor can be applied to the design of chaotic system, neural circuit and neural network circuit.

    • Comprehensive evaluation model of users' satisfaction based on gray relational analysis and AHP

      CHEN Wei-Peng, LIU Xu-Hao, TANG Ning-Jiu, LIN Tao, LIU Wen-Jing, PENG Jian

      2017,54(4):713-720

      Abstract:

      For the issue of less effective usability comprehensive evaluation on users' comments with uncertain information and complex evaluation indexes, a users' satisfaction comprehensive evaluation model is applied on usability research of production, which integrates gray relational analysis and AHP (Analytic Hierarchy Process). In order to enhance the objective of gray relational analysis, AHP method is used to determine the relative weights of evaluation index so as to establish comprehensive evaluation model of users' satisfaction model. With contrast experiment on the dataset of smart mobiles in different price, the satisfaction rank from our model is very similar to the one of actual sales. In addition, experiment result shows gray relational analysis can distinguish the satisfaction difference of productions more clearly. So above experiment results illuminate our model can comprehensively effectively evaluate users' satisfaction of production with incomplete assessment information

    • Personalized NewsRecommendation Technology Based on Improved Collaborative Filtering Algorithm

      HUANG Xian-Ying, XIONG Li-Yuan, LI Qin-Dong

      2018,55(1):0049-0055

      Abstract:

      The traditional collaborative filtering algorithm only based on matrix produced by user access history to make recommendation and sparse data,and also cannot reflect the user’s interests timely, contrary to these problems, the personalized recommendation technology news in the traditional collaborative filtering algorithm proposes the calculation of news text content similarity and the concept of the time window , the calculation of news content similarity also takes into account the part of speech and positions of the feature words in the news, the time window is used to create user interest model which will change over time; The experimental results show that the improved algorithm effectively improves the sparse problem of data which user has accessed and captures user interest timely, F-measure value improves the maximum 10% compared to the traditional algorithm, the highest value of mean absoulte error fell by 7%, greatly improving the quality of recommendation.

    • Research on DDoS detection based on BP neural network

      YANG Ke-Xin, SANG Yong-Sheng

      2017,54(1):71-75

      Abstract:

      Distributed denial of service attack (DDoS) is a common threat in today’s networks. While such an attack is not difficult to launch, defending a network resource against it is disproportionately difficult. This paper analysis some famous theories and methods on detection of DDoS network attacks systematically based on the fast neural network algorithm. Meanwhile, the attack traffic feature model which is constructed based on the packet length, packet transmission time interval and packet length change rate etc is proposed. Second, a method to optimize the parameters of the neural network error is also proposed by a large number of attempts. Finally, the UCLA dataset is used to carry out the contrast experiment of the parameters before and after the improvement. Experiments show that the proposed method can effectively detect DDoS attacks and has a better generalization ability.

    • Force-Directed embedded in community radius and radial tree hybrid layout algorithm

      REN Shu-Xia, WU Tao, ZHANG Shu-Bo

      2020,57(1):73-81

      Abstract:

      Force-Directed layout has the defects of display complex network community structure.Although the cluster layout algorithm can display the community structure,the nodes in the community are crowded,which is not conducive to observing the structural features and the connected relationship of nodes in the community.therefore,Force-Directed embedded in community radius and radial tree hybrid layout algorithm is proposed.Firstly,The algorithm uses the K-means algorithm to divide the network nodes into communities.Then,the community radius is determined by the number of nodes in each community,and the community radius is embedded into the repulsion and gravity to achieve the effect of cluster layout.Finally,the radial tree layout is used for each community to hierarchically visualize nodes within the community.In the experiment,congestion ratio,point distribution deviation,node deviation and other indicators are used to show that the algorithm can reduce the congestion and the node layout deviation.The visual results prove that the layout structure of the algorithm is obvious,and the nodes are clearly structure and easy to understand.

    • Research of Stock Time Series Based on probabilistic Suffix Tree

      CHENG Xiao-Lin, ZHENG Xing, LI Xu-Wei

      2018,55(1):0061-0066

      Abstract:

      this paper introduces a Probabilistic Suffix Tree (PST) method based on the time series symbolization, and constructs a stock forecasting model based on the combination of time series symbolizationa and PST. In addition, the Markov Model MM and the Auto Regressive Moving Average Model (ARMA) are compared with the forecasting model of this paper.The stock of 10 CSI 300 indices is used as the experimental sample. The results show that the stock forecasting model proposed in this paper is better than the MM model and the ARMA model,and proves the validity of the forecasting model proposed in this paper.

    • Multi-target Tracking Data Association Algorithm Based on Greedy Strategy

      ZHANG Liang, WANG Yun-Feng

      2018,55(1):0056-0060

      Abstract:

      Abstract:In this paper,a new association method is proposed to tackle the data association problem of multi-target tracking.In this algorithm, building the associative matrix with the Euclidean distance and the 1-Norm of state vector between tracks and points firstly.And using the associative matrix find the most suitable(Maximum matching success rate)points for every track. If the points just marked by one track, update this track directly; if the points marked by many tracks, choose the track with highest probability to update. Monte-Carlo Simulation experiments show that this algorithm guarantees the updating points for every tracks are the best points among all present points.

    • Virtual machine image clustering deduplication algorithm based on improved Simhash

      ZHANG Can-Yang, LIU Xiao-Jie

      2020,57(1):57-65

      Abstract:

      In the cloud environment, traditional physical servers are gradually being replaced by various virtual machines.The storage space, occupied by virtual machine images hosted in cloud data centers, has increased dramatically.How to efficiently manage these image files has become one of research hotspots in the cloud computing.Due to the large number of blank duplicate blocks inside the virtual machine image, which leads to a high degree of internal redundancy of the image.Second, different virtual machine images may run the same operating system and applications, so that there is more duplicate data between the images.For a large number of virtual machine images, the traditional deduplication strategy will generate huge time overhead, and will consume huge memory space and CPU resources, which will affect the performance of the data center.This paper proposes a multi level deduplication method based on improved Simhash algorithm for massive virtual machine images, which divides a complete image file into operating system image segment and application data image segment, extracts the feature values of each part, and uses DBSCAN clustering algorithm for grouping the image segments.In this way, the image segments with higher similarity are grouped into one class, thereby decomposing the global deduplication into smaller internal weights with higher repetition rate, and the fingerprint index data is completely stored in the memory.This deduplication algorithm greatly reduces the number of disk I/Os and shortens the deduplication time.

    • Optimization of multi joint robot motion of hydraulic drilling vehicle based on ant colony algorithm

      WEI Peng, LUO Hong-Bo, ZHAO Kang, LONG Wei

      2018,55(6):1171-1179

      Abstract:

      Hydraulic rock drilling rig plays an important role in modern tunneling construction. The existing hydraulic drilling rig is completed by the operator when locating the hole position. The order of locating holes and the time to search holes is not optimized, which results in time waste and low efficiency. In view of the above problems, in this paper, the multi node motion and the time of locating hole path of long arm multi joint intelligent rock drill are optimized for large tunnel section and complex hole system. The innovative research is as follows: by the rock drilling tunnel form and excavation mode analysis, as well as the explosion hole parameters setting, a collision free planning is proposed for the left and right manipulator drilling tasks. At the same time, the total change time of each joint variable of the multi joint manipulator is used as the optimization objective function. The ant colony algorithm is used to optimize the objective function, and the optimized hole finding path with the shortest hole positioning time is obtained, which improves the positioning and finding efficiency of the hydraulic rock drilling rig mechanical arm.

    • Question Based Importance Weighting Network for Answer Selection

      XIE Zheng-Wen, XIONG Xi, JU Sheng-Gen

      2020,57(1):66-72

      Abstract:

      According to the defects of the classic text matching model in the question and answer system, a question based importance weighting network for answer selection is proposed. At present, the existing answer selection model generally matches the question sentence and the answer sentence directly, ignoring the influence of noise words in the question sentence and the answer sentence on the match. To solve this problem, the self attention mechanism is firstly used to modify the weight of each word in the sentence to generate a "clean" question sentence vector. The word level interaction matrix is then used to capture the fine grained semantic information between the question sentence and the answer sentence. It weakens the influence of noise words on the correct answer. Finally, the multi window CNN is used to extract the feature information to obtain the prediction result. The comparison experiments on benchmark datasets show that the performance of the BIWN model in the answer selection task is better than the mainstream answer selection algorithm, and the MAP value and MRR value are improved by about 0.7%~6.1%.Finally, the multi-window CNN is used to extract the feature information to obtain the prediction result. The comparison experiments on benchmark datasets show that the performance of the BIWN model in the answer selection task is better than the mainstream answer selection algorithm, and the MAP value and MRR value are improved by about 0.7%-6.1%.

    • Accuracy analysis and improvement of different Alpha-Beta filtering algorithms

      LIU Chang-Juan, WANG Yun-Feng, YANG Ling

      2018,55(2):265-270

      Abstract:

      Maneuvering target tracking is an important part of radar application system, target tracking accuracy is regarded as an important index when evaluating an algorithm's performance for the maneuvering target tracking,it is the focus of attention of most people. The characteristics were summarized through the analysis and comparison of four traditional Alpha-Beta filtering algorithms, and according to these characteristics, an Adaptive alpha-beta filter algorithm was obtained by improving traditional algorithms. Compared with the traditional Alpha-Beta filtering algorithm, the Adaptive Alpha-Beta filter algorithm is best in overall filtering results, and also has the highest accuracy.

    • Affine Invariant Feature Matching Algorithm on Sparse-to-Dense Mechanism

      LI Yun-Tian, ZHU Ying-Qi, LI Zheng, SUN Xiao-Yu

      2018,55(1):0067-0072

      Abstract:

      In this paper, an affine invariant feature matching algorithm is based on sparse features into dense features is proposed, in which sparse features include coordinates, scale, affine parameters etc., dense features include information of Gaussian kernel, area descriptor. Based on the Affine-SIFT algorithm, this algorithm improves the shortcomings of sparse feature extraction in the feature extraction phase. Because the dense information can only extract the feature when the sparse parameter is full of enough detection conditions, it can not match the characteristic (including sparse and dense parameters) that can be matched, in this paper, we will reconstruct the sparse features by using the sparse features to construct the new simulation images, and further extract the sparse features on the basis of the simulated images, and can detect the matching features that can not be detected in the original image, Feature set the probability of matching, to improve the correct match the number of goals. Compared with the ASIFT, the algorithm, in this paper, which can significantly increase the number of correct feature matching points is proved by experiments. In addition to the extending method of the ASIFT. The proposed method can also be used to extend other feature extraction and matching methods with sufficiently parameters of sparse feature, and apply to precisely target recognition, target classification and 3D reconstruction etc.

    • genetic-immune algorithm based on receding horizon for aircraft landing scheduling problems

      CHEN Wen-Ping, LIANG Wen-Kuai, LI Yi

      2016,53(2):311-318

      Abstract:

      Flight scheduling has been a complex and key task for the air traffic control (ATC), and aircraft landing scheduling (ALS) problem is one of the core issues. ALS is a NP-hard problem with a large scale and multi-constraints characteristics. Thus, in order to solve the flight landing problem effectively and rationally, a flight landing scheduling algorithm based on receding horizon and genetic-immune algorithm (RHC_HGIA) is proposed. RHC_HGIA solves the problem of flight landing by two aspects mainly, one is that selecting the flights that are waiting to land and need to be optimized based on the receding horizon length and size which have been set; on the other hand, optimizing The selected flights which are waiting to land by using genetic-immune algorithm and determining actual landing time of them. the flights that have been optimized form a new flight landing sequence, selecting the flights from the sequence that the actual landing time of them in the field within a given time range to land. Then resetting receding horizon length and re-selecting the flights to be optimized until all pending landings have landed so far. In this paper, simulation is conducted in the airport control simulation system on the base of an airport of 20 flights to be landing of one day. Simulation results show that, RHC_HGIA algorithm can solve ALS problem preferably, and comparing with traditional flights landing scheduling algorithm(FCFS), the extra costs of flight is reduced much more.

    • An Adaptation Social Spider Optimization Algorithm Based on Dynamic Multi-swarm Strategy

      LIU Zhou-Zhou, LI Bin

      2017,54(4):721-727

      Abstract:

      In order to improve the samples diversity and convergence properties of social spiders optimization algorithm (SSO), an adaptation social spider optimization algorithm based on dynamic multi-swarm strategy (DMASSO) is proposed. According to the algorithm samples diversity and evolutionary level, the spider population is dynamically divided into different sizes leading groups and supporting groups, and the adaptive learning factor and Gaussian disturbance factor are introduced to improve the algorithm update ways, which helps to improve the algorithm global optimization ability and maintain the diversity of the sample population. For the test results of typical characteristics functions show that compared to SSO algorithm, SFLA algorithm and other optimization algorithms, the new algorithm has better convergence speed and convergence accuracy.

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    Physics
    • The comparison of several time phase unwrapping methods

      zhaowenjing, chen wen jing, su xian yu

      2016,53(1):110-117

      Abstract:

      Abstract: One of the key steps in 3D optical shape measurement based on the structured light projection is the phase unwrapping. The unwrapping issue about the complicated phase map is also the difficult step of the methods. The temporal phase unwrapping provide a useful tool to obtain the continuous phase map from the complicated wrapped phase map. Along the time direction, the temporal phase unwrapping is independently carried out from a 3D distribution demodulated from grating fringes with different pitches projected on the tested object. Therefore the problem of the error propagation in 2D phase unwrapping algorithm can be avoided. Followed by the comparison among the typical temporal phase unwrapping methods, including the negative exponential method, three pitches unwrapping method, three pitches heterodyne unwrapping method and its improved technique, a segmentation curve fitting method is used to improves the phase calculation accuracy. The computer simulations and experiments are carried out to verify that the phase error is deduced greatly through the segmentation curve fitting.

    • Pathology of the Fermionic Representation of Transverse Ising Model

      GUO Xiao-Ting, LI Peng

      2016,53(1):124-130

      Abstract:

      When studying the quantum Ising chain in a transverse field, we usually transform the spin operators to fermion operators by applying the Jordan-Wigner transformation,i.e.we take it for granted that the spin model and corresponding fermionic model are equivalent naively. But deliberate treatment could reveal that the equivalence accompanies some delicate conditions.Redundant degrees of freedom should be projected out carefully, especially for finite length of chain. In this paper, we compare the two models in detail so as to find the conditions of equivalence of them,including the interaction, the boundary conditions, and odevity of the number of lattice sites.We also exemplify in detail how to project out the redundant degrees of freedom for the fermionic representation.

    • Effect of many-body interactions on the equation of state for Solid Argon

      LI Ji-Hong, ZHENG Xing-Rong, PENG Chang-Ning

      2016,53(1):131-137

      Abstract:

      By using ab initio self-consistent field Hartree-Fork methods and atomic clusters expanding theory and employing Gamess program, two- and three-body interaction energies and the equation of state for solid argon in fcc crystal have been quantificationally calculated at the neighboring atomic distance R=2.40 -4.00 Å under high pressure. In addition, the convergence and truncation of atomic energy multi-body expansion are analyzed. It is found that two-body contribution to the cohesive energy is positive, while the three-body contribution is negative in solid argon under high pressure. At high pressure, only the consideration of the two-body contribution will overestimate the cohesive energy, hence it is necessary to introduce the three-body negative effects. The phenomenon of the experiment under 80GPa can be explained by considering the three-body potential.

    • Preparation and luminescent of Zn1-xMnxS nanoparticles

      WANG Qing, ZHANG Xu-Dong, WEI Zhi-Qiang, DAI Jian-Feng, LI Wei-Xue

      2016,53(1):152-156

      Abstract:

      Mn-doped ZnS (ZnS:Mn) nanoparticles were prepared via hydrothermal method, studied effects on photoluminescence that different proportions Mn ions on Zn1-xMnxS. The composition, morphology, microstructure and optical property of the sample were characterized by X-ray diffraction (XRD).The results showed that the Zn1-xMnxS (x = 0,0.01,0.03,0.05,0.07,0.10) nanoparticles were spherical hexagonal structure of nanocrystalline, uniform particle size between 15 ~ 20nm. At room temperature, using the UV excitation wavelength is 350nm stimulate Zn1-xMnxS nanoparticles. Blue light emission which is produced by transition between shallow donor level and manganese t2 level can be obtained. Luminous intensity with the increasing amount of manganese-doped increased decreased after the first.And emission peaks have a mobile with the change of manganese-doped content. The reason may be related to sulfur vacancies which influence shallow donor level of ZnS. The proportion of zinc-manganese has an impact on the amount of sulfur vacancies and level position.

    • Nuclear coupling parameters affect hyperon phase in the neutron star

      MU Xue-Ling, JIA Huan-Yu, HONG Bin, ZHOU Xia

      2016,53(1):118-123

      Abstract:

      Hyperon emergence and the proportion of hyperon have significant influence on the properties of the neutron star, How the different nuclear interaction models affect the neutron star is an important physical problems. In terms of the relativistic mean field theory, selecting different nucleon coupling parameters of neutron stars to calculate the density of hyperons. And we will find that the different nucleon coupling parameters have different extent influence in hyperon emergence and the transition of neutron star to hyperon star. The interaction potential of sigma meson and omega meson potential have a significant influence, but the influence of rho meson potential is small. These results have important reference value in researching the massive neutron star.

    • Theoretical research on structural stability and electronic structure of XeF2 under high pressure

      WANG Hai-Yan, YANG Bing-Fang, WANG Biao, SHI Rui-Li

      2017,54(4):781-784

      Abstract:

      The structural properties of XeF2 in the pressure range from 0 to 80 GPa are studied by plane-wave pseudopotential density functional theory method. The calculated values are in agreement with the experimental data. Based on the calculated elastic constants of XeF2 under different pressures, the I4/mmm structure of XeF2 is confirmed to be stable in the pressure range from 0 to 80 GPa. The band gap of XeF2 at different pressure is calculated and the band gap is found to decrease with the increase of pressure. When the pressure is greater than 10 GPa the band gap of XeF2 increases linearly with the increase of pressure, which indicates that XeF2 transforms from the insulator to semiconductor and has more and more strong metallic with the increase of pressure.

    • Elastic and electronic properties of CuAlSe2 under pressure: A first-principle study

      ZHOU Meng, LU Zhi-Peng, TAO Ying-Qi, HUANG Ao, ZHOU Le, ZHOU Xiao-Yun, HU Cui-E

      2017,54(4):771-780

      Abstract:

      We employ the first-principles plane wave method in the frame of density functional theory (DFT) to investigate the equilibrium lattice structure, the mechanic, thermodynamic and electronic properties of CuAlSe2 compound. The lattice constants, the bulk modulus B0 and its pressure derivative B0’ are calculated. Based on the quasi-harmonic Debye model, we also obtain thermal expansion coefficient. It is noteworthy that the variation tendencies of these parameters are investigated detailed with pressure. In addition, we also calculate the elastic constants of CuAlSe2 compound. Results show that the elastic constants C11、C33、C12 and C13 increase with increasing pressure, whereas the influences of pressure on elastic constant C44 and C66 are not obvious. The calculated elastic constants satisfy the hecriterion of mechanical until the pressure grows to more than 15GPa, which suggests the structure phase transition of CuAlSe2 may be happened. We also investigate the shear sound velocity VS, longitudinal sound velocity VL, and Debye temperature ΘE from our elastic constants, as well as the thermodynamic properties from quasi-harmonic Debye model. We obtain the dependence between the heat capacity Cv and pressure, and the same as thermal expansion coefficient α. At last, the pressure dependences of band structures and density of states are also investigated, which shows that the value of TDOS decreases with the increase of the pressure.

    • First principle study on properties of singlr-layer phosphorene with doping iron, cobalt and nickel

      LIU Yuan-Quan

      2017,54(6):1257-1262

      Abstract:

      In this work, structural stability, band structure, density of states and charge density difference of iron, cobalt and nickel doped single-layer phosphorene are studied by first principles method. The research of the thesis can be mainly divided into following results, the adsorption stability of adsorption in top at phosphorus position of cobalt is stronger than that of iron and nickel in the adsorption system; as well as the stability of Ni doped system is the strongest in the doping systems. The adsorption of iron, cobalt and nickel on the surface of phosphorus can be better regulate the energy band structure, so we can get controllable performance ofsemiconductor materials. The band gap values were 0.52 eV, 0.56 eV and 0.4 eV as iron, cobalt and nickel doped singlr-layer phosphorene, respectively.Nearest neighbor phosphorus atoms appeared electronic aggregation phenomenon at around iron, cobalt and nickel doped; because of iron, cobalt and nickel have two electrons in 4S orbit and phosphorus atoms are easier to get electrons

    • First principles studies on mechanical properties of ZrB3 and NbB3 under high pressure

      AO Te-Gen, YING Chun, ZHAO Er-Jun, HOU Qing-Yu

      2017,54(3):547-552

      Abstract:

      The mechanical properties and the electronic structures of transition metal compounds ZrB3 and NbB3 (m-AlB2, OsB3 and MoB3 structures) under high-pressure are studied by using the first-principles within density functional theory. It was found that m-AlB2 is the most stable structure under normal pressure. The pressure-induced phase transition occurs at the pressure of 40 Gpa, OsB3 structure becomes the most stable one under high pressure. m-AlB2-NbB3 has a maximum shear modulus of 204 GPa, the highest Debye temperature of 921 K, and the highest hardness of 27.3 GPa. The harnesses are estimated to be 24.9 GPa, 22.6 GPa and 19.8 GPa for MoB3-NbB3, OsB3-NbB3 and m-AlB2-ZrB3, respectively. The calculated density of states (DOS) illustrated that the electronic structures of considered compounds are governed by the strong hybridization between M-4d and B-2p states. All compounds are metallic.

    • First-principles calculations on phase transition and elastic and thermodynamic properties of NaH

      AN Xin-You, ZENG Ti-Xian, REN Wei-Yi, WU Wei-Dong

      2017,54(4):791-798

      Abstract:

      The structural phase transition, elastic and thermodynamic properties of NaH were investigated by the plane-wave pseudopotential method within the density functional theory. The equilibrium lattice parameters a0 , elastic constants Cij, bulk modulus B0 and it’s derivative B0′ were calculated. The results are consistent with the experimental and theoretical data. From the usual condition of equal enthalpy, the phase transition of NaH from B1 to B2 phase occurs at 30.5 GPa with a volume collapse of about 4.5%, consistent with the experimental (29.3±0.9GPa) and calculated (37.0 GPa) results. The static finite strain technique was used to calculate elastic constants Cij at the different pressures. Furthermore, the elastic wave velocities, Debye temperature Θ and elastic anisotropic factors of NaH were also investigated in detail. Through the quasi-harmonic Debye model, in which the phononic effects were considered, the thermodynamic properties such as the specific heat capacity and thermal expansion coefficient of NaH were obtained in the whole pressure range from 0 to 50 GPa and temperature range from 0 to 1500 K.

    • Plasmons in Antimonene Nanostructure: First Principles Study

      SHU Xiao-Qin, ZHANG Hong

      2018,55(1):0125-0128

      Abstract:

      The excitation characteristics of surface plamons of the antimonene nanostructure was studied by time-dependent density functional theory (TDDFT). The absorption spectra were given for impulse excitations polarized in the armchair-edge direction (X-axis) and zigzag-edge direction (Y-axis). The edge configuration effects the absorption spectrum. The distribution of indued charge infers thethe main plasmon resonance modes are the bonding dimer plasmon mode(BDP) in the low-energy resonance region.

    • Elastic and thermodynamic properties of LaB6 under pressure: a first-principles study

      HE Xi, FU Min, YU Bai-Ru

      2017,54(6):1239-1249

      Abstract:

      The elastic and thermodynamic properties of CsCl-type structure LaB6 under high pressure are investigated by first-principles calculations based on plane-wave pseudopotential density functional theory method within the generalized gradient approximation (GGA). The calculated lattice parameters of LaB6 under zero pressure and zero temperature are in good agreement with the existing experimental data and other theoretical data. The pressure dependences of the elastic constants, bulk modulus B (GPa), shear modulus G, Young’s modulus E, elastic Debye temperature ΘE, Poisson ratio σ, compressional wave velocity VL and shear wave velocity VS are also presented. An analysis for the calculated elastic constants has been made to reveal the mechanical stability of LaB6 up to 14 GPa. The thermodynamic properties of the CsCl-type structure LaB6 are predicted using the quasi-harmonic Debye model. The variation of thermal expansion coefficient α, the variation of the heat capacity Cv are obtained systematically in the ranges of 0-14 GPa and 0-1500 K. At last, the pressure dependences of the density of states are also investigated.

    • First-principles calculation on the electronic structures and optical transmittance of Al2O3 codoped with Co-Mo

      FANG Wen-Yu, WANG Xiao-Wen, ZHENG Qin, GAO Shen

      2020,57(1):135-139

      Abstract:

      The electronic structures and optical properties of intrinsic, Co, Mo doped and Co-Mo codoped Al2O3 compounds are calculated by using first-principles plane-wave ultrasoft pseudopotential method based on the density functional theory. The results show that the binding energies of Mo single doping and Co-Mo co-doped Al2O3 are low and easy to synthesize. Both Co and Mo dopings belong to the n-type doping, which can enhance the carrier concentration of the doping system, and thus improving the conductivity of Al2O3. The impurity levels of the doped system are mainly composed of co-3d state electron and mo-4d state electron,which are the intrinsic factors that affect the optical properties of doped Al2O3. After doping, the absorption spectrum is redshifted and the optical properties change mainly in a low energy range. The transmittance of the Al2O3 film in the range of 200~800 nm is about 92%. The transmittances of the Al2O3 doped by Mo single and co-doped by Co-Mo are as high as 93~98% in the band of 600~780 nm. In the short-wave ultraviolet region of 200~280 nm, the transmittance of Co single doping can be as high as 95%. Therefore, three doped Al2O3 can be used to prepare various optical transmission films.

    • Research on focusing system in the neutral particle calibration source

      FU Hong-Tao, WAN Lin, YUAN Zhi-Ling, WANG Chao, LUO Xiao-Bing, ZANG Lin-Ge

      2020,57(1):118-122

      Abstract:

      A focusing system for neutral particle calibration source has been designed. Three dimensional electromagnetic simulation software CST has been used to simulate the transmission of the beam in the neutral particle calibration source. The distance between the single lens and the accelerating tube, as well as the influence on the focus voltage and the acceleration voltage on beam trajectory have been investigated. In addition, a plastic scintillator has been used to preliminary measure the profile of the beam flow on the ion source testing device. The experimental results are consistent with the simulation calculation, and our work has important reference value for the calibration of neutral particle analyzer.

    • First Principles Study on the Hydrogen Storage Properties of La Doped BN Nanotubes

      ZHANG Ning-Chao, REN Juan

      2018,55(1):0105-0110

      Abstract:

      The hydrogen adsorption on La-doped single BN nanotubes were investigated by first-principles based on density functional theory. Our calculated results show that the binding energy of La metal is large enough and ensure the stability toward recyclability. The maximum of six hydrogen molecules be adsorbed on the La-doped BN nanotube which can store up to 4.50 wt%. The density of states show that hybridizations between La-5p,5d ,6s states and B-2p, C-2p orbitals appear near the Fermi level. It is clear that the positive charge of La cation can polarize the incoming H2 molecules. The research of this paper has a certain guiding significance for the synthesis of high performance BN nanotube hydrogen storage materials.

    • High-order harmonic generation from He+ driven by the chirped pulse combined with the unipolar pulse

      LIU Hang, LI Yi, YAO Zhen, FENG Li-Qiang

      2018,55(1):0118-0124

      Abstract:

      The generations of the high-order harmonic and the attosecond pulse from He+ ion driven by the chirped pulse combined with the unipolar pulse have been numerically investigated. The results show that by preparing the initial state as the coherent superposition of the ground and the first excited states of He+ ion, the harmonic yield is enhanced by 6 orders of magnitude in comparison with the single ground initial state case. Further, by introducing the laser chirp and the unipolar controlling pulse, the cutoff energy of harmonic spectrum is remarkably enhanced, and the interference structure of harmonic is also reduced. Further, with the introduction of the spatial inhomogeneous effect, the harmonic cutoff can be further extended, resulting in a super-bandwidth of 320 eV. By superposition of harmonics, three attosecond X-ray pulses with durations from 45 as to 48 as can be obtained, which is 5 ~ 6 orders of magnitude improvement in comparison with the single ground initial state case.

    • The study of GMOR relation in the NJL model at finite temperature

      CAI Wen-Hua, WANG Qing-Wu

      2020,57(1):113-117

      Abstract:

      In quantum chromatic dynamics (QCD) theory, Gell-Mann-Oakes-Renner (GMOR) is a low-order approximate identity which associates with quark condensation, meson mass and pion decay constant at zero temperature. In this paper, according to the QCD efficient theory and the Nambu-Jona-Lasinio (NJL) model, based on the two-flavor NJL model and the Proper Time Regularization (PTR), we derive the temperature dependence of quark condensation and the temperature dependence of quark mass in Quark condensation at finite temperature, and try to study the establishment of GMOR relation under this temperature condition. The results show that near zero temperature, the GMOR equation is valid within the allowable range of error, but with the increase of temperature, beyond a certain limit, the equation is no longer valid, and the deviation between the two sides of the equation is increasing.

    • Three Dimensional Reconstruction Based on Improved Empirical Mode Decomposition

      LI Xu-Qin, CHEN Wen-Jing, SU Xian-Yu

      2018,55(1):0111-0117

      Abstract:

      Aiming at the problem of the edge error caused by the traditional empirical mode decomposition method, an improved empirical mode decomposition method is proposed for eliminating the decomposition error in the edge zones of the signals in this paper, in which, a mirror extension method and Gerchberg extrapolation iteration is introduced to eliminate the decomposition error at edges position, respectively. The improved method can effectively suppress the mode decomposition error caused by the signal edge and improve the decomposition accuracy of the EMD. It is also applied in the analysis of the deformed fringe pattern for eliminating the background components in 3D optical measurement, by which a better reconstructed result of 3D surface can be obtained.

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    Electronics and Information Science
    • Time Variation Characteristics and Assessment of Electromagnetic Environment in a Campus

      ZHANG Ming-An, ZHAO Xiang, XU Jin-Hai, YAN Li-Ping, HUANG Ka-Ma

      2016,53(1):93-97

      Abstract:

      With the increasing complexity of the electromagnetic environment (EME), it is necessary to perform actual measurement and evaluation of the EME. Because of the temporal dynamic and random variation of the EME, time variation characteristics of the EME in a campus are considered in this paper. By choosing sampling points in different regions of the campus, respectively measuring electric field value of the sampling points during different time periods, and using statistical analysis of the measurement data, we get the figures of probability density distribution and time variation curve of the electric field. And then, the time variation characteristics of the actual EME are analyzed and discussed, the distributions of the EME in different regions are compared, as well as a brief evaluation of the electromagnetic radiation level in the campus is given.

    • A novel error resilience scheme for key frames in Wyner-Ziv video coding

      LIU Xiao-Juan, QING Lin-Bo, XIONG Shu-Hua, OU Xian-Feng

      2016,53(1):98-104

      Abstract:

      In Wyner-Ziv video coding system, correct transimission and accurate decoding of key frames would affect the whole system performance directly. However, in wireless communication system, data loss of key frames often happened due to network failure, network congestion or other reasons. Data lossy seriously affect the decoding quality. This paper presents a novel solution for the data loss of key frames under the conditions of feedback channel. In the solution, by sending some extra Wyner-Ziv code streams along with the origin key frames, errors of the damaged image at the decoder can be high-efficiently corrected and restored. Simulation results show that the proposed solution could reconstruct the damaged image effectively, and the quality could be improved up to 20dB compared with typical error concealment method when the data loss ratio is 1%~20%. Furthermore, R-D performance of key frames could be improved even if the data loss ratio is very high.

    • Quantum authentication and key agreement scheme for SIP protocol

      YANG Guang, NIE Min, YANG Wu-Jun

      2016,53(1):87-92

      Abstract:

      To overcome the shortcomings of current SIP safety scheme, such as the incapability to detect the wiretap and the vulnerability of the classical key system in case of quantum computation attack, this paper proposed a novel user authentication and key agreement scheme that combined quantum safe communication methods and SIP protocol. The SIP server prepared the three particle W states and distributed two of them to the SIP users. The random inserted particles were measured first to detect the wiretap; then the rest of the W states were operated and measured to authenticate the user. After that, every particle of the W states was measured randomly and the two SIP users got the initial conversation key according to the results of the effective measurements. The performance analysis shows our scheme is capable of resisting the impersonation attack and wiretap attack, thus can increase the safety of SIP protocol effectually.

    • Using homogenous dielectric superstrate to enhance the bandwidth of a microstrip antenna

      ZHENG Zhi, CHEN Xing, XU Guang-Hui, WANG Hao, HUANG Ka-Ma

      2016,53(2):326-330

      Abstract:

      A superstrate is able to significantly increase the gain of an antenna, and this superstrate based technology has been widely used. However, the studies about the effects of superstrates on the return loss of the antenna are limited. In this work, taking homogenous dielectric superstrates and a probe-fed microstrip antenna as examples, using numerical simulations, the effect of superstrates on the return loss of an antenna is investigated. The simulation results show, by proper design of some structural parameters, such as the distance between the superstrate and the antenna, the feeding location of the antenna and so on, the dielectric superstrate can improve both the gain and the impedance bandwidth. A prototype is fabricated and measured, and the measured results shows that it has a gain of 14.5 dBi and a |S11|<-10dB impedance bandwidth of 11.19% , which verifies the simulations.

    • Method for solving class imbalance of named entity recognition dataset

      xu lidan, Liu jiayong, He xiang

      2020,57(1):82-88

      Abstract:

      The public data sets in named entity recognition research are often class label imbalanced,which limits the further performance improvement based on statistical learning model methods. Aiming at the above problems, a data class label balancing method based on genetic algorithm is proposed, which modifies the fitness function and gene combination rules tried to balance the dataset by generating new samples to augment the original dataset. In order to verify the validity, the proposed method was compared with the balanced undersampling method and the random oversampling method by using the Bi LSTM CRF model on the CoNLL 2003 and JNLPBA datasets respectively. The results show that the proposed method increased the recall rate by 3.26% and the F1 value by 1.70% on the CoNLL2003 dataset, and the recall rate by 2.44% and the F1 value by 1.03% on the JNLPBA dataset. The experimental results demonstrate that the proposed method can effectively alleviate the class imbalance and improves the effect of named entity recognition.

    • Malware Clustering Based on Graph Convolutional Networks

      liukai, fangyong, zhanglei, zuozheng, liuliang

      2019,56(4):654-660

      Abstract:

      Many new types of malwares are often modified by attackers based on the existing malwares. Therefore, family homology analysis of malwares can help to study of evolutionary trend and traceability of malwares. In this paper, starting from API call graphs of malwares and combined with Graph Convolutional Networks (GCN), we proposed a similarity calculation and family clustering model for malwares. Firstly, we extract API call graphs of malwares with disassembly tools and the attribution of the API functions in the graphs are labeled. Then, we select key API functions by its contribution to the malware families and the API call graphs of malwares are constructed. We use GCN and Convolutional Neural Networks (CNN) as the model of the malware similarity calculation which the inputs are the API call graphs. Finally, we use DBSCAN algorithm to cluster malwares. The experimental results show that the proposed method can achieve 87.3% accuracy and can effectively cluster malware families.

    • Joint Angle, Range and Velocity Estimation for bi-static FDA-MIMO Radar

      ZHAO Zhi-Hao, WANG Zhi-Min, SUN Yang

      2017,54(6):1202-1210

      Abstract:

      It is known that there is a contradiction between range estimation and velocity estimation due to the influence of pulse repetition frequency (PRF) in traditional phased-array (PA) radar. In this paper, a joint unambiguous angle, range and velocity estimation method is proposed for bi-static multiple-input-multiple-output (MIMO) radar with frequency diverse array (FDA). Owing to the FDA, there is a little frequency increment between the arrays and the transmit steering matrix carries angle, range even velocity information. Consider the range-angle coupling in transmit steering matrix, a subarray-based transmitted waveform and decoupling approach are designed. Utilizing the ESPRIT algorithm and ambiguity resolve methods based on FDA, the direction-of-departure (DOD), direction-of-arrival (DOA), range and velocity parameters are estimated unambiguously. Additionally, Cramér-Rao bounds (CRB) for these parameters are derived and the performance of this radar is analyzed. Simulation results indicates the validity of the proposed method.

    • Hyperspectral image classification of multi-layer local perceptual convolutional neural networks

      ChiTao, WangYang, ChenMing

      2020,57(1):103-112

      Abstract:

      To solve the problems on high nonlinearity in spectral features in hyperspectral image classification, a classification algorithm, based on multi layer perceptron convolutional layer and batch normalization layer improved convolutional neural network in spectral domain processing, is proposed to improve the nonlinear feature extraction ability. By constructing a seven layer network structure, the algorithm implements a multi layer local sensing structure, analyzes the spectral information pixel by pixel, distinguishes the spectral information of different targets, takes the full spectrum segment set as input, discards the spatial information, and uses the momentum gradient descent training. The algorithm trains multi layer local perceptual convolutional neural networks to realize the extraction and classification of spectral features of different target objects. In the experiment, two sets of hyperspectral remote sensing images are used for comparative analysis. Taking the Pavia University data set as an example, in the case of 3 600 training samples, the test set is 1 800 samples, the accuracy of the proposed method is 9023% and the accuracy of the LeNet 5 and Linear SVM method are 8794% and 9000% respectively. In the case of 21 000 training samples, the test set is all samples, the accuracy is 9723%, 9664% and 9240% respectively for the proposed method, LeNet 5 and Linear SVM method. The experimental results show that the proposed method is superior to the traditional neural network in the case of small training set, which can effectively extract the data features, and is superior to SVM algorithm for the small sample classification in terms of accuracy and computational cost. In the large scale training set, this method shows good learning ability and is superior to LeNet 5 in classification accuracy. The multi layer local perceptual network structure proposed in this paper enhances the learning ability of nonlinear features, it can utilize hyperspectral images much more effectively than traditional SVM and general deep learning networks, both in small sample classification and large sample classification. The spectral domain information of the pixel by pixel point can effectively improve the classification accuracy.

    • Community discovery in weighted social networks based on similarities of common neighbors

      LIU Miao-Miao, GUO Jing-Feng, MA Xiao-Yang, CHEN Jing

      2018,55(1):0089-0098

      Abstract:

      In order to divide communities accurately in weighted networks, a hierarchical clustering method IEM based on the similarity and modularity is proposed. Firstly, the similarity of the two nodes is defined based on attributes of their common neighbors. Then, the most closely related nodes are clustered fastly according to their similarity to form the initial community and expand it. Lastly, these communities are merged with the goal of maxmizing the modularity so as to optimize division re sults. The algorithm achieves more reasonable and effective community division for weighted network by three steps of initializing, expanding and merging communities. Correctness and effectiveness of the algorithm are verified through experiments on many weighted networks using weighted modularity as evaluation index. Results show that IEM is superior to weighted CN, weighted AA and weighted RA. Moreover, it can achieve the higher quality of community division in weighted networks compared with CRMA algorithm.

    • Relational intimacy degree handover algorithm of LTE heterogeneous network

      YANG Jing, LI Peng-Cheng, YAN Jun-Jie, ZHOU Xiao-Jun

      2018,55(1):0073-0080

      Abstract:

      To meet the need for Quality of Experience(QoE), the User Equipment(UE) has to handover frequently in the coverage area between Macro cell and Femto cell, with the increase of total handover times, the UE will occupy some physical resources continuously, resulting in lower system throughput. Relational intimacy degree handover algorithm of Long Term Evolution(LTE) heterogeneous network is proposed, which estimates the relational intimacy between UE and Femto cell by gathering the historical information of the former access to the latter, then sorts the priority ordering for UE waited for handover by using this attribute, and makes the handover decision by taking the receiving signal strength, speed and Femto cell bandwidth available into account. Simulation results show that the proposed algorithm can reduce the total handover times obviously, avoid the unnecessary handover times and improve the system throughput effectively.

    • Measurement and Correlation Analysis of Electromagnetic Environment in a Campus

      XU Jin-Hai, ZHAO Xiang, ZHANG Ming-An, YAN Li-Ping, ZHOU Hai-Jing

      2016,53(2):347-352

      Abstract:

      In this paper, the electromagnetic environment (EME) in a campus is measured and then analyzed adopting statistical method. The results establish the spatial distribution of the EME in this campus, and the characteristics of EME in different areas are compared. The probability density functions (PDF) of the measured data are calculated and depicted, and some other valuable results are also obtained. These measured data and statistical results provide necessary support for evaluating and analyzing the EME. And these data could be utilized to affirm theoretical analysis method of EME. Finally, this paper presents a method that using Correlation to represent the complexity of EME. Two electromagnetic field intensity probes are used to sample the electric field strength of different positions simultaneously, the Correlation Coefficients between two electric field strength versus two different time series are calculated to measure the complexity of EME, and the figures of correlation coefficient corresponding to each component and total field versus distances are presented.

    • Study on the Influence of Metal Boundary Movement on the Heating of Microwave Multimode Cavity

      YE Jing-Hua, YU Yu-Tian, HONG Tao, ZHU Hua-Cheng, HUANG Ka-Ma

      2018,55(1):0081-0088

      Abstract:

      As a new and efficient heating method, microwave has a great advantage in chemical catalysis and material processing. However, the non-uniformity of microwave heating has limited its application in the chemical industry. A multi-mode microwave cavity with moving metal wall is designed in this paper. In the heating process, the electric field distribution of the cavity is constantly changing by moving the metal wall of the cavity, thereby achieving the purpose of improving the heating uniformity. In the simulation, by using the moving mesh method, the simulation of the whole heating process can be realized by a continuous algorithm. The accuracy of the algorithm is verified by comparing with the electric field distribution of the cavity and reflection coefficient of the port with that of the discrete position. By comparing the temperature coefficient of variation (COV) of the heated material, it can be considered that the heating uniformity of the microwave multimode cavity with a moving metal wall is increased by 18%-38% compared to that of the fixed size multimode cavity. Meanwhile, we analyzed the effect of different metal wall movement modes on the heating effect, and concluded that one can choose the metal wall movement mode according to the properties of the material and other requirements.

    • Research on quantum image algorithm based on IBM Q

      Ren fengjuan, Teng QIZhi, Wang ZhengYong, He XiaoHai, Zhou Lei

      2020,57(1):89-95

      Abstract:

      In order to develop and validate the quantum image processing algorithm on quantum computer, combined with quantum computing operation on IBM quantum experiment platform (IBM Q) and quantum image processing theory, a quantum image segmentation method based on IBM Q platform was designed. An improved enhanced quantum representation (IEQR) was proposed based on the existing novel enhanced quantum representation (NEQR). The quantum image segmentation circuit, which consists of the quantum bit string comparator (QBSC) and the Control swap (Cswap) gate, is initialized according to the IEQR. Finally, quantum image segmentation of 2×2 and 4×4 size images are realized on IBM Q and local classical computer simulator. The experimental results demonstrate the feasibility and effectiveness of the algorithm and the superiority of quantum computers is validated.

    • Classification model based on mRMR and factorization machines algorithm

      Wangmei, Long Hua, Shao Yubin, Du Qingzhi

      2020,57(1):96-102

      Abstract:

      Many scholars have made some achievements in aggregation analysis of terrorist events by using the data set of "Global Terrorism Research Database"(GTD) with game theory, k nearest neighbor method and support vector machine. However, data sparsity and high dimensional multi redundancy are not well considered in the previous research, which may lead to low accuracy of clustering classification. This paper proposes a TFM classification model based on "Minimal redundancy maximal relevancy" (mRMR) combined with " Factorization Machines " (FM), in which the incremental search method is used to find approximately optimal features to address the high dimensional multi redundancy and the data sparsity is tackled with FM method. TFM model is then used to make quantitative classification on the pre processed terrorist attack data. The experimental results show the proposed TFM model, in terms of Matthews correlation coefficient (MCC), is increased by 49.9%, 2.5% and 2.3% respectively compared with naive Bayes (NB), support vector machine (SVM) and logistic regression (LR). The comparative result demonstrates that TFM model is feasible to some extent.

    • Efficiency Improvement of Magnetic Resonant Wireless Power Transfer System Based on Ferrite Reflector

      LI Yong-Feng, GUO Qing-Gong

      2017,54(4):742-746

      Abstract:

      A ferrite reflector-based optimization design of magnetic resonant wireless power transfer (WPT) system to improve transmission efficiency is proposed. The WPT system composed of four resonators is considered as a two-port network to deduce the transfer efficiency. Then a magnetic resonant WPT system whose receiving and transmitting coils have a diameter of 30cm is designed and manufactured. The measured transmission efficiency is above 90% at the distance of 30cm while decreases to about 40% when the distance increases to 60cm. Measured results are in good agreements with simulated ones. Based on this WPT system, two different ferrite reflectors are introduced to improve the transmission efficiency. Results show that the different size of magnetic reflectors may have positive or negative effects on transmission efficiency. By optimizing the ferrite reflector, the maximum 15% improvement of transmission efficiency is obtained at the distance range of 30cm to 90cm.

    • Research on application of early warning of students achievement based on data mining

      fantiecheng, liu bopeng

      2019,56(2):267-272

      Abstract:

      Academic achievement is the most important and most basic indicator for evaluating a student's learning situation. The analysis of academic performance is beneficial to teachers to master a student's learning situation and conduct the targeted teaching and counseling, while for the students, knowing in advance what happens to their future learning is also beneficial for students to discover their own problems which could be prevented in advance. Most of the existing research work is based on the analysis of the curriculum, historical performance or behavioral data to predict the student's total score, while few studies focus on combining a student behavior with his or her grades to comprehensively predict a student’s learning in all future courses. This paper, from a new perspective, uses the three aspects data of student behavior, personal attributes and historical achievements which are identified by the influencing factors based on students' different curriculum dynamics in the future, the early warning of students' achievement is predicted with support vector machine, the experiment results show the exploratory work of data mining applied in education has certain significant meaning for the teachers as well as for students.

    • Gray level DAG maximum entropy based on quantization resolution for Medical image tone enhancement

      SONG Lu, FENG Yan-Ping, WEI Ya-Bo

      2018,55(2):316-322

      Abstract:

      In order to improve the medical image sharpness and contrast, and improve the computational efficiency, we proposed the gray level DAG maximum entropy based on quantization resolution for Medical image tone enhancement. Firstly, we used a simple piecewise autoregressive (Piecewise autoregressive PAR) image target model for recovery, and taked into account the error of analog to digital conversion to use least squares algorithm to estimate PAR model parameter, which obtain high resolution image histogram restoration model; Secondly, aiming at the problem of low contrast may exist, the least squares algorithm for constrained optimization problems was modeled in DAG, which constructed a hue preserving constraint optimization model of maximum entropy image enhancement, and the characteristics of the DAG figure Monge theorem was used to reduce the computational complexity; Through the above two steps, the image details and contrast enhancement in the process of medical image enhancement are realized. The simulation results show that the proposed algorithm can provide more effective medical image enhancement effect.

    • Detection Algorithm of Cascaded Adaboost License Plate Based on HSV color model and MB_LBP Features

      MA Yong-Jie, LI Huan, LIU Jiao-Jiao

      2018,55(2):290-294

      Abstract:

      License plate detection is an important part of the license plate recognition system, which deeply affects the accuracy of license plate recognition. A method for cascade adaboost license plate detection based on HSV color model and multi-block local binary patterns (MB_LBP) is presented to realize fast and accurate license plate detection and recognition. Firstly, the license plate image is transformed from RGB color space to HSV color space, and the ratio of the blue pixels to the total pixels of the license plate is counted to construct the first class strong classifier. Then, the MB_LBP feature is extracted from the license plate character samples, and the feature selection and the classifier training are carried out by using the Adaboost classifier training method. Finally, a new license plate detection algorithm is formed by using the Cascade structure detection method. Experiments results show that the license plate detector improves the detection rate and the detection speed.

    • The Research of Drain Induced Barrier Lower Effect for SOI Strained Silicon Schottky Source/Drain MOSFET with High-k Gate Dielectric

      XU Li-Jun, ZHANG He-Ming, YANG Jin-Yong

      2017,54(4):753-758

      Abstract:

      The SOI strained silicon schottky source/drain MOSFET with high-k gate dielectric is a potential device realizing small size MOSFET, which combines the advantages of strained silicon engineering, high-k gate dielectric, SOI structure and schottky source/drain. A model for the structure is proposed by solving two dimensional Possion’s equation, which takes into account for the impact on the source/drain schottky barrier height for electron of image force barrier and size quantization effect, then the drain induced barrier lower model is investigated based on the threshold voltage model. The experiment data of drain induced barrier lower extracted from literature is compared with the model, which verifies its correctness, and discuss the variety relationship between drain induced barrier lower and several parameters. The result shows that drain induced barrier lower increases with strained silicon thickness, channel doping and germanium fraction increasing, decreases with channel length, gate dielectric constant, intrinsic schottky barrier height for electron and drain source voltage increasing. The device can suppress drain induced barrier lower effect greatly through adjusting the model parameters properly, which can provide some reference for the design of SOI strained silicon schottky source/drain MOSFET with high-k gate dielectric device and circuit.

    More

    Biology
    • Construction and Application of RecET Recombination System in Zymomonas mobilis

      LI Tao, CAO-Qing-Hua, ZHANG Yi-Zheng, WU Yan, Tan Xue-Mei

      2016,53(1):209-214

      Abstract:

      Zymomonas mobilis is a Gram-negative bacterium with excellent ethanol-producing capabilities. The ability of ethanol yield and substrate utilization can be further improved through genetic manipulations. In this study, in order to increase the recombination efficiency of foreign genes into chromosome of Z. mobilis, the RecET genes were cloned into the E. coli-Z. mobilis shuttle expression vector pSUZM3a, resulted in pSUZM3a-RecET. The adhA gene encoding the alcohol dehydrogenase and tetracycline resistant gene were used as the target and the selection marker genes, respectively. The PCR fragments of tetracycline resistant marker with 60bp flanking sequences homologous to adhA were electroporated directly into Z. mobilis ZM4 cells which harbored pSUZM3a-RecET. After the PCR analysis and DNA sequencing, it was found that the RecET-mediated recombination reaction resulted in adhA gene replaced by tetracycline resistant gene. The result showed that RecET system could make efficient, rapid targeted gene knock-out with only 60bp homologous arm in Z. mobilis.

    • Expression and Purification of Recombinant Chicken TSHβ, FSHβ, and LHβ Proteins

      YAN Zhen-Xin, MO Chun-Heng, WANG Ya-Jun, LI Juan

      2016,53(1):163-168

      Abstract:

      Gonadotropin(Follicle-stimulating hormone (FSH), Luteinizing hormone (LH))and Thyroid-stimulating hormone (TSH) are glycoprotein secreted by pituitary. Gonadotropin plays a key role in the regulation of the development and function of vertebrate gonads. TSH participates in development and metabolism by stimulate the thyroid to secrete T4 and T3. In the study, we prepared the prokaryotic expression plasmids encoding chicken TSHβ subunit, FSHβ subunit and LHβ subunit and produced the three recombinant proteins using RT-PCR and molecular approaches. We also purified the recombinant proteins by Metal Ion Affinity Chromatography. This work paves the way for future preparation of polyclonal antibodies against chicken TSHβ, FSHβ and LHβ in rabbits.

    • Human elongation factor 1A1(eEF1A1) promotes drug tolerance in lung cancer cell line

      DING Mu-Ran, LIU Tao, LI Lin

      2016,53(1):198-202

      Abstract:

      Human translational elongation factor 1A (eEF1A)is a multi-functional protein besides its roles in protein translation system. The protein expressional level of eEF1A is related to cell viability in oxidative stress and apoptotic process. Based on the knowledge of multifunctional roles of eEF1A and its relation to cell viability, we studied the possible effect of the isoform eEF1A1 on the drug resistance in cancer cell lines. The eukaryotic expression vector containing eEF1A1 sequence was constructed and was transiently transfected into human lung cancer cell line H1299. After verifying the expression of FLAG -eEF1A1, MTT assay was utilized to measure the cell viability of transfected H1299 after treatment by two common anti-cancer drugs. H1299 transfected with eEF1A1 showed enhanced drug tolerance to both taxol and adriamycin. Lung cancer cell highly expressing EEF1A1 behave more tolerance to antineoplastic drugs.

    • Screening of Phospholipase D producing Strains and its transphosphatidylation activity

      SHI Chuang, WANG Yi-Ding, MA Qin-Qin, YUAN Xiang-Hua

      2016,53(1):215-220

      Abstract:

      Using soybean Phospholipids as substrates,one strain which expressed Phospholipase was isolated from soil near oil mill ,the Phospholipase produce by SNUPLD-6 was identified which contain Phospholipase D . According to its mor -phological characteristics and ITS sequence , The strain SNUPLD-6 was identified as Geotrichum candidum. study on the Conditions for the growth of the bacteria and the PLD reaction conditions which expressed by SNUPLD-6. The results showed that its optimum growthtemperature is 30℃ .its optimum growth pH value is 6.0,its optimum carbon source is glucose,its optimum nitrogen source for the beef extract and peptone 50% each. the optimal fermentation time of phospholipase D producing is 3d, its optimum transphosphatidylation-temperature is 32℃. its optimum transphosphatidylation pH value is 6.0,its optimum reaction buffer for pH=5.5 0.02M HAc -NaAC buffer, its Optimal metalion activator as Ca2 +, Zn2 +.

    • HPLC determination of activity of UGT75B1、UGT71B6、UGT71C5 and the kinetic analysis

      CEN Yong-Yi, LIU Zheng, LI Xu-Feng

      2016,53(1):169-174

      Abstract:

      The cDNA sequences of UGT75B1, UGT71B6, UGT71C5 were cloned by PCR method and then were constructed into glutathione S-transferase gene fusion vector PGEX-6P-1. All of the plasmids were transformed into E. coli strain BL21 individually for recombinant protein expression. Recombinant UGTs were purified from supernatant of cell lysates. To investigate the activity of recombinant UGTs, HPLC was employed to determine their activity to catalyze ABA and p-aminobenzoic acid. Analysis by reverse-phase HPLC was carried out using a Kromasil C18 column (250mm×4.6mm, 5μm) and glucose ester was separated by a linear gradient of 10%-100% methanol in H2O (all solutions contained 2.5ml/L of acetic acid and 0.4ml/L of triethylamine) or 10%-20% acetonitrile in H2O (all solutions contained 1ml/L of trifluoroacetic acid). The results showed that only UGT75B1 presented strong p-aminobenzoic acid acylglucosyltransferase activity and the others had lower activity. All of the recombinant UGTs had ABA-GE activity. However, UGT71B6 performed highest activity. Analysis of Michaelis-Menten kinetics of UGT75B1, UGT71B6 and UGT71C5 indicated that their Km was 0.73, 0.43 and 0.45 mM, respectively. In conclusion, our investigations demonstrate that UGT75B1 has higher p-aminobenzoic acid acylglucosyltransferase activity than ABA-GE activity. It seems that p-aminobenzoic acid is the specific substrate of UGT75B1. In comparison, UGT71B6 and UGT71C5 with similar Km perform higher ABA-GE activity.

    • TAp73α-mediated cisplatin sensitivity was suppressed by miR-330 in colorectal cancer cell HCT116

      HUANG Ling, TONG Ying, XIAO Zhi-Xiong, ZHANG Yu-Jun

      2016,53(1):228-234

      Abstract:

      The p53 family member p73 is a transcription factor involved in the regulation of cell cycle, apoptosis and cancer cell drug-resistant. Here we reported that knockdown of p73 sensitized HCT116 colorectal cancer cells to cisplatin treatment independent of p53. Hsa-miR-330 (miR-330) was identified to be able to directly repress the expression of TAp73α. Overexpression of miR-330 decreased the protein levels of endogenous TAp73α and phenocopied the effect of p73 knockdown. Restoration of TAp73α eliminated miR-330-induced chemosensitivity toward cisplatin. Our results demonstrated a novel function of TAp73α to impair cisplatin sensitivity in colorectal cancer cells which can be repressed by miR-330, thus provided an effective strategy for therapeutic treatment of cisplatin-resistant cancer cells.

    • Study on the application of aquatic plants in Chengdu Egret Wetland Park

      YU Lai, CHEN Shu-Jing, LIN Wei, LUO Yan-Yun

      2016,53(1):221-227

      Abstract:

      Abstract: Based on field survey and analysis of data, the application status of aquatic plants in Chengdu Egret Wetland Park was studied, including the contents of species selection, planting modes, landscape effects and ecological functions, the monitoring and analysis of ambient air quality and surface water quality were also conducted. And then the advices were put forward for the further strengthening of application and growing management about aquatic plants in Chengdu Egret Wetland Park. The study provided a reference for the construction of ecological zones around the city of Chengdu in the future about the rational use of aquatic plants.

    • Cloning and expression regulation analysis of a JcKNOX1 gene, from Jatropha curcas L.

      SHI Xiao-Dong, TIAN Yin-Shuai, YAN Xiao-Xue, FANG Zhi-Rong, WANG Sheng-Hua, CHEN Fang

      2016,53(1):187-192

      Abstract:

      KNOX family genes,coding homeobox proteins,play an inmportant role in plant development.A novel homeobox gene,JcKNOX1,was cloned from the cDNA of Jatropha curcas L..The full-length ORF of JcKNOX1 was 693bp,encoding a protein of 230 amino acids residures.The predicted structure of JcKNOX1 showed that its theoretical isoelectric point and molecular weight were 6.13 and 25.92 kDa respectively.Phylogenic analysis indicated that JcKNOX1 was relation to Populus tomentosa and Citrus sinensis closely.By fluorescence quantitative PCR the expression levels were different as follows:stem apex>tender leaf>stem>leaf>flower>petiole>root,which showed that the JcKNOX1 expressed with high levels in developing organs.Meanwhile,JcKNOX was strongly induced by ABA and low temperature in Jatropha curcas L. seedlings.Through biology software prediction analysis indicated that JcKNOX1 might play an important role in light regulation,hormone regulation,expression of pollen-specific gene and abiotic stress of Jatropha curcas L..

    • Synthesis and evaluation of near infrared fluorescent dye BPAD-2 for β-amyloid plaques

      CHENG Yan, OUYANG Xiang-Shuo, LIANG Tian, ZHANG Zhi-Rong

      2016,53(1):193-197

      Abstract:

      OBJECTIVE We synthesized a benzopyrane derivative BPAD-2 with push-pull electronic structure, and assessed its fluorescence properties, labelling ability for beta-amyloid plaques, and blood-brain barrier penetrating ability. METHODS BPAD-2 was synthesized by condensation reaction with 1-(2-hydroxy-phenyl)-ethanone as the primary reagent, and confirmed by 1H-NMR and MS. Fluorescence spectra were observed; fluorescence staining was performed to evaluate labelling ability for beta-amyloid plaques; fluorescent imaging was performed to evaluate blood-brain barrier penetrating ability. RESULTS The emission maximum of BPAD-2 in PBS was at 658 nm; BPAD-2 showed bright red labelling of beta-amyloid plaques; BPAD-2 penetrated the blood-brain barrier and peaked at 10 min postinjection and showed reasonable washout from the brain. CONCLSION BPAD-2 showed specific labelling of beta-amyloid plaques and had good blood-brain barrier penetrating ability.

    • Extraction and physicochemical properties of Idesia polycarpa Maxim oil

      HUA Wan, YE Yang, WANG Zhan-Guo, CHEN Fang, TANG Lin

      2016,53(1):181-186

      Abstract:

      In this study, extraction method and decolorization as well as grease physical of the oil from the fruit of Idesia palycarpa were analyzed. The chemical compounds of the oil were separated and indentified by capillary GC-MS method. Meanwhile, the content of polyphenols from Idesia palycarpa oil were determined to provide the basis for the future development of the Idesia polycarpa Maxim. The results showed that the extraction rate by Soxhlet extraction was higher than the traditional press law, extraction rate reached 35%, while the traditional press law was 21%. Among diethyl ether, petroleum ether and n-hexane, the extraction rate by using petroleum ether with Soxhlet extraction was the highest. Through the extraction of oil, oil content of Idesia polycarpa was about 35%. Results also indicated that decolorization rate increased with the rise of the temperature, it has reached 45% while bleaching temperature up to 80℃. The main components of the oil were palmitoleic acid, palmitic acid, linoleic acid, oleic acid and stearic acid, the content of linoleic acid was the highest, up to 60%. In general, Idesia palycarpa has high oil content, and rich in linoleic acid in the oil, the results showed that Idesia palycarpa oil has considerable prospects for the development.

    • An evolutionary modular view of functional diversity in Arabidopsis uridine diphosphate glucosyltransferase

      FANG Yang, NIU Yu-Long, LIU Cheng-Cheng, LIN Jiang-Yi, LI Xu-Feng, YANG Yi

      2017,54(6):1317-1322

      Abstract:

      Uridine diphosphate (UDP)-glycosyltransferases (UGTs), belonging to the family 1 glycosyltransferases (GTs), play important roles in transferring glycosyl moieties and glycosylating secondary metabolites in Arabidopsis thaliana. Reconstructed phylogenomic trees can provide novel insights in studying evolutionary relationship and functions of this multigene family. By combining comprehensive phylogenetic profiles and reconstructed phylogenomic trees, we systemically analyzed 112 Arabidopsis UGTs. In total, we detected five distinct evolutionary conserved modules, and most UGTs were divided into the same module indicating a rather conserved evolutionary routine of Arabidopsis UGTs. We next manually collected the substrates of Arabidopsis UGTs and mapped them to orthologous groups, revealing evolutionary relationships of UGTs in binding specific substrates. By scanning 271 different species, we also predicted several unreported proteins that were closely related to Arabidopsis UGTs.

    • Complete sequence and comparative analysis of the chloroplast genome of the Chinese aspen (Populus adenopoda, Salicaceae)

      FAN Li-Qiang, HU Huan, ZHENG Hong-Lei, WANG Tian-Jing, WANG Ya-Ling, MA Tao, MAO Kang-Shan

      2018,55(1):0165-0171

      Abstract:

      Although Populus (Saliaceae) is an important group of forest trees in the sense of economy, ecology and scientific researches, few is known about the structural and sequence variation of chloroplast genome across the genus. We sequenced and characterized the complete chloroplast genome of the Chinese aspen (Populus adenopoda), and made comparative analyses of the structure variation of the chloroplast genomes of P. adenopoda and other 11 poplars. The P. adenopoda chloroplast genome is 158,591bp in length, exhibits a typical quadripartite structural organization, consisting of a LSC region of 84,634 bp, two IR regions of 27,667 bp and a SSC region of 18,623 bp. Comparison of the cp genome structure and gene order to those of the 12 Populus species indicated that the chloroplast genomes of this genus are rather conservative, only six large deletions or insertions were found across the whole genome. Phylogenetic analysis demonstrated that the 12 Populus species clustered into three well-supported clades, and Chinese aspen is most closely related to the white poplar, P. alba. Our work will better our understating of the evolutionary history of Populus, and will be useful to future population genetics and other molecular ecology studies of poplars based on chloroplast DNA sequences.

    • An Interaction of ABA Receptor RCAR12 with CARK3 in Arabidopsis thaliana

      HUANG Qi, LI Xiao-Yi, CHEN Jing-Bo, LI Jing-Xiang, LI Xu-Feng, YANG Yi

      2018,55(1):0179-0183

      Abstract:

      The phytohormone abscisic acid (ABA) is crucial for plant development and response to abiotic stress, including drought. ABA perceived by the ABA receptors, PYR/PYL/RCAR, which bound to ABA, and then recruit Protein phosphatase 2C (PP2C) to inhibit the PP2C acticity, thereby activating SNF1-RELATED PROTEIN KINASE2 (SnRK2s). Here, CARK3 and RCAR12 interact in yeast two-hybrid system and GST-pull down in vitro. Bimolecular fluorescence complementation (BiFC) was used to illuminate the interaction between CARK3 and RCAR12 in Nicotiana benthamiana in vivo. We could confer that CARK3 indeed interacts with RCAR12 in present study and the phosphorylation modulates the physiological response of the core ABA signaling pathway. Our results provide the foundation for further understanding of the regulatory network of phosphorylation of ABA signaling pathways core components.

    • The expression of long non-coding RNA LINC00941 in colorectal cancer and effect on cell proliferation

      WANG Cheng-En, LUO Yu, HE Zheng-Chi, XIAO Xue-Wei, LI Zong-Xin, LAN Yang, WU Chuan-Fang

      2017,54(6):1301-1305

      Abstract:

      To explore the function of a cell differentiation-associated long non-coding RNA (lncRNA) LINC00941 in cancer progression, we detected the expression of LINC00941 in 6 types of human cancer cell lines and HEK-293 cell line by real-time quantitative PCR. LINC00941 is highly expressed in colorectal carcinoma cell lines HCT116 and HCT116 p53-/-, lung carcinoma cell lines A549 and NCI-H1299, and melanoma cell line Stilling, especially in colorectal carcinoma cell lines. By detecting the RNA levels of LINC00941 in the tumor and normal tissues of colorectal cancer patients, we found that the expression levels were significantly increased in tumor compared with paired normal tissues. By shRNA(short hairpin RNA) interfering, we found LINC00941-knockdown HCT116 cells had lower proliferation rate compared with negative control cells, suggesting the correlation of LINC00941 and colorectal cancer progression.

    • Construction and crystallization of a novel DNA nanostructure

      LV Jia-zhen, HUANG Zhen

      2020,57(1):199-204

      Abstract:

      In the DNA triangle nanostructure, its corner is composed of Holliday junction in DNA homologous recombination.To further investigate it,the DNA triangle was modified by introducing the sticky end to the holiday junction motif to make it self assemble into a DNA nanostructure.The gel electrophoresis analysis showed that the migration rate of this new DNA nanostructure was faster than that of the DNA triangle. Without the distortion,the motif assembled to form a dimer structure instead of a trimer triangle. The DNA nanostructure was crystallized and modified with selenium to obtain high quality crystals. The DNA nanostructure and the structure of the Holliday motif under non-twisting tension will be further studied and determined in order to offer more insights into DNA nanomaterial interaction and self-assembly.

    • Study on the mechanism of Cordyceps cicadae extracts promote longevity in Saccharomyces cerevisiae

      YANG Li, YAN Meng-Li, LIU Ke

      2020,57(1):169-173

      Abstract:

      This study aims to explore the role of Cordyceps cicadae extracts (CCE) in resistance against H2O2 -induced oxidative stress and chronological lifespan extension in Saccharomyces cerevisiae. The experiments are performed with various concentrations of CCE to test the chronological lifespan extension. Then, the resistance against H2O2 induced oxidative stress was measured in terms of intracellular ROS accumulation. The mRNA levels of SOD2, GPX2 and CTT1 were measured by real -time PCR. The results indicate that CCE can prolong yeast chronological lifespan in a dose dependent manner. Furthermore, the CCE pre-treated cells accumulate significantly lower ROS in the case of H2O2-induced oxidative stress. Taken together these results suggest that CCE extends chronological lifespan and develops resistance against H2O2 induced oxidative stress through upregulation of CTT1 and SOD2.

    • Elevation of immunity to PCV2 vaccine by recombinant Tibetan pig interleukin-12 gene in chitosan nanoparticles

      SONG Ting-Yu, XIAO Yong-Le, ZENG Guang-Zhi, WAN Xiao-Ping, CHEN Yi, LI Jin-Hai, WANG Ze-Zhou, FANG Pengfei, GAO Rong

      2017,54(6):1345-1350

      Abstract:

      To study the regulation effect on vaccination of porcine circovirus-2 (PCV2) by co-delivering interleukin-12 (IL-12) cDNA via chitosan nanoparticles, two subunits of IL-12, P40 and P35 of Tibetan pig, were cloned into mammalian expression plasmid VR1020. VRIL-12 was transfected into HEK293 cells and PCR test was conducted. The results showed that IL-12 gene could express successfully. The recombinant plasmid was packaged into chitosan nanoparticles using ionic crosslinking method. The nanoparticles (VRIL-12-CNP) were confirmed to be nanoparticle size with good dispersion and positive charge. VRIL-12-CNP was then used to inoculate the 21-day-old piglets together with PCV2 vaccine. Blood samples were taken at day 0, 7, 14 and 28 post inoculation for analysis. The results showed that post vaccination the T cells such as CD3+, CD4+ , CD8+, and anti-PCV2 specific antibody, all increased significantly in the VRIL-12-CNP co-delivering pigs (P<0.05), the expression levels of TLR2, TLR7, IL-12, IL-4, IL-6 and IL-15 in the co-delivering group were significantly higher than those in control group (P<0.05), and the expression of STAT1, 3 and Bcl-2 gene was also increased significantly in the co-delivering pigs (P<0.05). Moreover, the net weight gain of the pigs in co-delivery group was significantly increased in the 28 days post inoculation (P<0.05). These results indicated that co-delivery of VRIL-12-CNP elevated swine innate immune response and both humoral and cellular immune response to PCV2, and VRIL-12-CNP is a promising safe and effective adjuvant to PCV2 vaccination.

    • Reproductive allocation changes from Saussurea parviflora in eastern edge of Qinghai-Tibet Plateau at various altitudes during flowering

      YANG Ya-Jun, WANG Yi-Feng, QI Ru-Lin, YANG Yang

      2018,55(1):0207-0213

      Abstract:

      To study the effect of elevation on the reproductive allocation of Saussurea parviflora during the flowering,sampling survey method and weighting after dried method are chosen so as to study Saussurea parviflora 's morphological features at various altitudes.It show that, firstly,during flowering,above-ground biomass in plant itself and its organs related to reproduction and vegetation has an obvious trend of decreasing as altitude goes up.Besides,its number and stem length also slope down little by little.On the contrary,tubuliflorous biomass and reproductive allocation take on a relative trend of increasing and prosperity.Secondly,a shift phenomenon in balance from tubuliflorous biomass and its number would probably be formed.Thirdly,in flowering,biomass in many aspects and reproductive allocation are potentially controlled by the environmental factor,altitude .Finally ,for the external resource is limited ,in order to relatively promote its productive growth ,this kind of smart plant weaken the vegetation growth by quietly inhibiting its individual size .In this way, Saussurea parviflora’s breeding success rate is greatly and amazingly lifted .

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    Mathematics
    • Positive solutions of third-order ∞-point boundary value problems

      GAO Ting, HAN Xiao-Ling

      2016,53(1):35-41

      Abstract:

      In this paper, we study the existence of positive solutions to the third-order ∞-point boundary value problem u'''+ λa(t)f(u) = 0, t ∈ (0,1),u(0) = βu'(0), u(1) =∑αiu(ξi), u'(1) = 0,where λ > 0 is a parameter, ξi∈ (0,1), αi∈ [0,+∞], and satisfy ∑αi>1,0<∑αiξi(2−ξi) < 1. a(t) ∈ C([0,1],[0,∞)), f ∈ C([0,∞),[0,∞)).By using Krasnoselskii’s fixed point theorem in cones, we can obtain the existence of the positive solution and the eigenvalue intervals on which there exists a positive solution if f is either superlinear or sublinear.

    • A BP-LSTM trend forecast model for stock index

      SUN Cun-Hao, HU Bing, ZOU Yu-Xuan

      2020,57(1):27-31

      Abstract:

      In this paper, according to the time series characteristics of financial data, such as stock index, stock price, etc, we introduce the Artificial Neural Network (ANN) and Recurrent Neural Network (RNN) in deep learning to stock index prediction and build a BP-LSTM model based on the Back Propagation (BP) neural network model and Long Short-Term Memory (LSTM) neural network model. Numerical analysis shows that the accuracy of our model is higher than that of the traditional machine learning models, and it also has some improvement compared with the ordinary LSTM model.

    • Sensor Selection for Hypothesis Testing in Wireless Sensor Networks

      QIAN Bo, MA Ting, SONG En-Bin

      2018,55(1):0007-0012

      Abstract:

      The well-known sensor selection issue is of great significance in wireless sensor network. We aim at selecting a subset of out of sensors to conduct the corresponding hypothesis test based on their observations such that the false alarm rate attains the minimum, which has been proved to be NP hard. In this paper, we relax the original problem to a tractable one and propose a new algorithm, which can achieve the KKT point. Moreover, compared with the existing algorithm, our algorithm is more efficient since it has lower computation complexity. Simulations also illustrate that the global optimum can be reached in most cases.

    • Iterations of tent maps

      YANG Yu-Chen, CHEN Xing-Wu

      2018,55(1):0031-0036

      Abstract:

      As a basic class of non-linear maps, tent maps is famous for their periodic point problem. And tent maps vertices as the points breaking the monotonicity in iterations have their own rules. This paper focuses on the change of the tent maps number of vertices under iterations, and gives the formula for the number of vertices in the specific case of parameter a=0.5,b=(1+√5)/4 and then the formula of the number of n-period points is given when b=1.

    • The 6-element case of S_1-Frankl conjecture (I)

      HU Ze-Chun, LI Shi-Lun

      2020,57(1):11-26

      Abstract:

      The union-closed sets conjecture (Frankl's conjecture) says that for any nite union-closed family of nite sets, other than the family consisting only of the empty set, there exists an element that belongs to at least half of the sets in the family. Recently, two stronger versions of the Frankl's conjecture (S_1-Frankl conjecture and S_2-Frankl conjecture for short) were introduced and partial proofs were given. In particular, it was proved that S_1-Frankl conjecture holds if n<=5, where n is the number of all the elements in the family of sets. In this paper and its sister paper, we prove that it holds if n = 6. This is the first part of the proof.

    • A new proof for monotonicity of sandwiched Renyi relative entropy

      wang you le, Luo Maokang, DENG Ke

      2018,55(2):257-259

      Abstract:

      Itis well known that in quantum information quantum relative is monotonically decreasing under the completely positive and trace-preserving maps. For a new proposed sandwiched R\'enyi quantum relative, a map that is linear trace-preserving and whose Hilber-Schmidt adjoint map satisfies Schwarz inequality, monotonicity still holds. We give a new proof of monotonicity of sandwiched R\'enyi relative entropy for $\alpha\in[\frac{1}{2},1)$. The proof is based on complex interplotation techniques, which already has been used to prove monotonicity under trace-preserving and positive map for $\alpha\in(1,\infty)$.

    • Characterization of Optimal Feedback for SLQ with General Filtration

      REN Yan

      2018,55(1):0042-0049

      Abstract:

      One of the fundamental issues in Control Theory is to design feedback controls. Which is well achieved in the case of linear quadratic control problems. To date, the study of this problem in the stochastic setting is focused much on the natural filtration. In this paper, we utilize the notion of transposition solution to give a sufficient condition for the existence of an optimal feedback control for the stochastic linear quadratic control problems with random coefficients in the general filtration setting, and show it is also necessary for 1-dimensional system.

    • Stochastic multi-resonance in a cancer growth system with non-Gaussian noise

      ZHANG Xiao-Yan, YUE Hong-Yun

      2018,55(4):667-672

      Abstract:

      Stochastic resonance and stochastic multi-resonance of a cancer growth model modulated by non-Gaussian noise and Gaussian noise are investigated in terms of the path integral approach and the adiabatic limit. The expression of signal-to-noise ratio (SNR) is obtained. The numerical results indicate that the SNR exhibits stochastic multi-resonance behavior when the SNR is a function of the multiplicative noise intensity, additive noise intensity, or the parameter of the non-Gaussian noise q. Meanwhile, it is also shown that the cross-correlation intensity and the self-correlation time can enhance the phenomenon of stochastic resonance.

    • Stochastic resonance of underdamped harmonic oscillator with random mass driven by periodic modulated noise

      WANG Chuan-Yi, REN Rui-Bin, DENG Ke

      2016,53(6):1183-1189

      Abstract:

      In this paper, stochastic resonance of an underdamped harmonic oscillator with random mass and driven by periodic modulated noise is investigated. The fluctuation of oscillator mass is modeled by a dichotomous noise while the internal noise is assumed to be Gaussian. Using the Shapiro-Loginov formula and the Laplace transform technique, exact expressions of first moment of the steady-state response and output of the system are presented. Then some simulations are implemented to study the dependence of long-time behavior of the first moment on variety of the system parameters. It is shown that the output amplitude non-monotonically depends on the signal frequency, the noise parameters and the system parameters, which indicates the occurrences of bona fide stochastic resonance, generalized stochastic resonance and parameter-induced stochastic resonance. Furthermore, based on the exact expressions it is demonstrated that interplay of the mass fluctuation and the periodic modulated noise can generate some novel cooperation effects, such as double-peak resonance as well as one-valley resonance.

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    Chemistry
    • Structure and Spectral Properties of HgmSen(m=1,2,3,n=1,2) Molecular and Molecular Ion lusters

      SHANG Long-Chen, LIU Xin-Ping, LI Jiao, NI Shu-Ping, LIAO Hong-Hua

      2016,53(1):138-144

      Abstract:

      This paper adopted the LANL2DZ pseudopotential basis set and B3LYP method to calculate the microstructure and electronic properties of HgmSen(m=1,2,3,n=1,2) molecules and molecular ion clusters. Meanwhile, it utilized the time-dependent density functional theory to calculate the absorption spectra, thus obtaining the ground state structure, electronic properties, binding energy, energy gap, dipole moments and other microscopic properties. Then it analyzed the frontier molecular orbital characteristics, identified all the harmonic vibration mode and absorption spectroscopic properties. The results show that: when m+n=1~3, the linear and angular types are the stable geometry with ground state; when m + n = 4 ~ 5, the ring type is the stable geometry with ground state, besides, compared with other molecular clusters, HgSe2 molecular cluster have the greatest stability, binding energy and the minimal energy gap. HgmSen(m=1,2,3,n=1,2) molecules and molecular ion clusters have better electron donors, receptors and other active sites, that is, great electrical conductivity. The maximum absorption wavelength λmax of each cluster with different composition lacks of regularity, but for the molecular clusters with the same composition and its corresponding positive and negative ions, there appears significant red shift or blue shift. The results could provide theoretical reference for the further experimental and applied research, and it is conducive to studying the nature of experiments as well as certain laws of massive condensed matter.

    • Synthesis and Characterization of Micro- and Nano- Metal-porphyrin Coordination Polymer

      YANG Jian-Dong, HUANG Shan

      2016,53(1):145-151

      Abstract:

      Micro- and nano-scale metal-organic complexs not only have size effect, but have an adjustable assembly unit, which shows a lot of good performance. in this paper, we synthesized nanoscale mertal-porphyrin complexs by a simple and green method. by choosing the different metal ions, the different nanostructures (0D, 1D, 2D) of metal-porphyrin polymer was abtained by controlled assemble unit. its structures were characterizatized by scanning electron microscopy (SEM), infrared spectroscopy (IR), x-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and were detailed examinated of the impact and dynamica growth of the metal-porphyrin polymer.

    • Syntheses, structures and characterizations of rare earth metal center coordination polymers based on bifunctional ligands

      WANG Xiao-Fang, JIANG Zhi-Qiang, TIAN Cong-Xue

      2020,57(1):140-146

      Abstract:

      The coordination polymers ([Dy(TZI)(H2O)4]•4H2O (1) and [La(HTZPI)(HC2O4)(H2O)3]•H2C2O4 (2)) have been synthesized by involving the bifunctional ligands (5-tetrazolylisophthalic acid (H3TZI) and 5-(4-(1H-tetrazolyl) phen) isophthalic acid (H3TZPI)) as linkers coordinating with rare earth metal ions (Dy3+/La3+). The using synthesis methods are hased on solvothermal synthesis and slow solvent evaporation. Crystal structures are characterized by X-ray single crystal diffraction, which show that the two compounds correspond to one-dimensional double-stranded chain and two-dimensional layer structure, respectively. It is notable that for this bifunctional ligand the tetrazolyl group is invalid when it coordinates with rare earth metal centers. Meanwhile, the thermal stabilities and the luminescent properties of them are investigated.

    • Nonlinear dielectric behavior study of chemical reactions in a strong electric field

      HONG Tao, TANG Zheng-Ming, ZHU Hua-Cheng, LAN Jun-QIng, HUANG Ka-Ma

      2017,54(1):131-134

      Abstract:

      In the presence of a strong electric field, novel phenomena always happen in chemical reactions, including the change of chemical reaction rate and the shifting of chemical equilibria. However, the mechanism is still unknown. This paper studies the interactions between chemical reaction systems and strong steady electric fields. Based on the theory of molecule reorientation, the modified Smoluchowski equation is expanded by the Legendre polynomials. The general expression of polarization is derived by considering the second-order nonlinear response. The nonlinear variation is also discussed through a simple isomerization reaction. The result shows that the ratio between the second-order nonlinear term and the polarization is proportional to the electric field. Meanwhile, the condition for which the result applies is also discussed.

    • Dynamic adsorption and elution performances of H2TiO3-lithium adsorbent loaded on ceramic foams

      ZHANG Li-Yuan, LIU Yi-Wu, ZHOU Da-Li, YAO Qian-Qian

      2017,54(6):1275-1280

      Abstract:

      H2TiO3-lithium adsorbent was loaded on cordierite-based ceramic foams by the sol-gel process. The adsorption and elution of Li+ by the obtained samples were studied with the ion exchange columns via the dynamic process. The effects of liquid flow speed, Li+ concentration and single column/multi columns on the adsorption capacity and enrichment factor of Li+ were studied. The results indicate that it needs a long time for the lithium adsorbent loaded on ceramic foams to reach the leakage, and the adsorbent has a high operational adsorption capacity. In a certain range, flow rate of the eluent does not affect enrichment factor of Li+ apparently. The adsorbent does not have the ability to enrich Li+ with a high concentration. However, it is capable for the adsorbent to enrich a low level of Li+. The enrichment factor of Li+ can at least reach 26.55 times by adding hydrochloric acid to adjust pH of the effluent liquid to equal to that of the original eluent and using the obtained liquid as the eluent repeatedly.

    • Study of Adsorption Characteristic of Uranium(Ⅵ) on Clay Rock

      LAI Jie, LIU Chang, LENG Yang-Chun, CHENG Jian-Feng, TUO Xian-Guo

      2017,54(4):815-821

      Abstract:

      In this paper, experimental study on static absorption was carried out for Alashan clay rock on Inner Mongolia. To explore the factors which may influence absorption characteristic of U(Ⅵ) on clay rock, including contact time, U(Ⅵ) initial concentration, solid-liquid ratio, pH value, ionic type and ionic concentration. The following results are obtained. The absorption rate of U(Ⅵ) on Alashan clay rock in Inner Mongolia is quite fast with adsorption equilibrium achieved in 24 hours. The optimum adsorption ratio is 1:200, and the optimum adsorption concentration is 160 μg•mL-1.The absorption capacity of clay rock was enlarged with the increasing of pH value. When pH value is at 8, the ability of absorption reaches the best. The absorption capacity of Uranium is largely hindered by Ca2+、CO32- and HCO3-, which have a great effect on the absorption ability of U(Ⅵ). The distribution coefficients of K+、Na+、Cl-、NO3-、SO42- can be changed with the change of ionic concentration, The surface adsorption of U(Ⅵ) on clay rock is dominated by inner-sphere complexation. The studies indicate the adsorption behavior of U(Ⅵ) on clay rock has a great significance on settling high level radioactive waste in China.

    • A comparative study of non-isothermal kinetics of fluoroether rubber under different atmosphere

      ZHAO Qi, zhang rong, PI Hong

      2017,54(2):364-370

      Abstract:

      The pyrolysis characteristics and kinetics of fluoroether rubber in air and nitrogen flow were studied by thermogravimetric analysis at five different heating rates. The kinetic parameters of the pyrolysis process were calculated using the method of Flynn-Wall-Ozawa and the mechanism of reaction were investigated using the method of Popescu. The results suggested that as the heating rates increasing, the pyrolysis temperature of the sample is moved to be higher. There is only one peak in DTG curves. The sample is more stable under nitrogen flow and the pyrolysis process of it is promoted by oxygen. It was found that the average value of the activity energy in air is 172.5kJ/mol, while 260.9kJ/mol in nitrogen. The pyrolysis process in air are well described by the model of Three dimension (R3) between 340°C and 370°C, by the model of Ginstling-Brounshtein (G-B) between 370°C and 380°C, and by the model of Zhuravlev (Zh) between 380°C and 400°C. While the thermal decomposition process in nitrogen are well described by the model of Ginstling-Brounshtein (G-B) between 400°C and 430°C, by the model of Three dimension (R3) between 430°C and 460°C.

    • Progress on the synthesis and photocatalytic applications of graphitic carbon nitride with high surface area

      NIU Jin-Ye, XIE Yi, WANG Lu-Yao, WANG Qian, ZHANG Yong-Kui, WANG Ya-Bo

      2018,55(5):1067-1077

      Abstract:

      Graphitic carbon nitride (g-C3N4) possesses good physical and chemical stability, suitable band structure and efficient visible light response, which has attracted numerous attention for photocatalytic applications. As heterogeneous catalyst, high surface area can provide abundant reaction sites, increase contact between reactants and catalyst, and enhance mass transfer, which are beneficial for catalytic efficiency enhancement. This review focuses on the preparation and photocatalytic applications of g-C3N4 with high surface area. Two major strategies are reviewed, which are template method for porous g-C3N4 preparation and exfoliation for thin-layer g-C3N4 nanosheet preparation. In addition, the photocatalytic applications of g-C3N4 are introduced. Finally, the prospective of g-C3N4 is described.

    • The first principles calculation Visible light on photocatalytic properties of Main Group C-Si-codoped TiO2

      WANG Qing, WANG Shuai, DAI Jian-Feng, LI Wei-Xue

      2017,54(1):135-140

      Abstract:

      In this work, the electronic structures, charge density differenceand optical properties of Si and C codoped anatase TiO2 are studied by using the plane-wave ultrasoft pseudopotential method of density functional theory (DFT). The calculated results reveal that C-Si-codoped anatase TiO2 results in band gap narrowing that increases the probability of electronic transition from the impurity energy levels to the conduction band (about 1.7eV), then improves the solar energy utilization, the existence of impurity energy levels in the forbidden gap reduces the carrier transition energy. The C-Si-codoped TiO2 has been helpful for enhancing the absorption coefficient under visible-light region, especially, among the three models, the third model exhibits the largest value of absorption coefficient under visible-light region.

    • Density functional study of styrene

      HE Wei-Ping, HUANG Ju, WANG De-Tang, LIU Xiao-Jing

      2016,53(6):1322-1328

      Abstract:

      The molecule of styrene was investigated with the density functional theory (DFT), and the molecular geometries was optimized by using B3LYP method at different levels of basic sets. Based on the optimized geometries, the molecular orbitals, the energy levels, the highest occupied orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), the infrared absorption spectrum (IR) and Raman scattering spectrum (Raman), the nuclear magnetic resonance (NMR), and the ultraviolet-visible absorption spectroscopy (UV-Vis) have been obtained with the density functional theory (DFT). According to the calculation results of the molecular orbitals and energy levels, the attributes of the highest occupied orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were mainly discussed. The simulated results of the infrared absorption spectrum (IR) and Raman scattering spectrum (Raman), the nuclear magnetic resonance (NMR), and the ultraviolet-visible absorption spectroscopy (UV-Vis) were compared with the experimental data, and the spectral data were concisely analyzed and discussed.

    • Study on the Interaction between Potassium Dehydroandrograpolide Succinate with Bovine Serum Albumin by Spectroscopic Methods

      LIU Li, CHENG Fei-Xiang

      2017,54(2):351-356

      Abstract:

      Dehydroandrograpolide Succinate (PDS) is a drug, widely used to treat viral pneumonia, viral upper respiratory tract infection such as anti-inflammatory drugs, known as the “Chinese medicine antibiotics”. Herein, Under the optimal conditions,fluorescence and absorption spectroscopy were used to study the interaction of PDS with bovine serum albumin (BSA) and effects of metal ions at different temperatures. The rate constant (Kq), apparent quenching constant (Ksv), binding constant (KA) and static fluorescence quenching association constant (KLB) and binding site number(n) were calculated using Stern-Volmer, Lineweaver–Burk and Double logarithm equations. The results show that PDS is able to bind to BSA. The probable quenching mechanism of BSA by PDS was mainly static quenching due to the formation of a PDS-BSA complex. The results of thermodynamic parameters indicate that electrostatic force plays the main role in the binding process and the binding process was spontaneous. The obtained data for binding sites of n approximately equal to 1 indicated that there was a single class of binding site for the BSA with PDS. The primary binding site for PDS was located at sub-domain ⅡA and ⅢA of BSA and near by tyrosine residue. There was almost no cooperative effect. The results obtained from synchronous fluorescence showed that the interaction between BSA and PDS caused the conformational changes of BSA. Pb2+, Mn2+, Ni2+and Cu2+ competed with the interaction of PDS with BSA, increasing medical effectiveness. Cr3+ promoted on interaction and prolonged drug effect time. The obtained results not only provided a theoretical basis for revealing the pharmacokinetics and further research on development of new anti virus herbs drugs.

    • Motion pattern of the complex involved in klebsiella pneumoniae carbapenemases and β-Lactamase inhibitor protein

      ZUO Ke, DU Wen-Yi, DAI Tian-Yang, LIU Wei, LIANG Li, hujianping

      2017,54(3):585-594

      Abstract:

      Carbapenems, used in clinical treatment of multi-drug resistance bacterial infection, can be hydrolyzed by Klebsiella pneumoniae carbapenemases, which weaken the treatment effect of gram negative bacterial infection. It’s an important means of improving the clinical efficiency of these antibiotics to develop novel, potent and specific Klebsiella pneumoniae carbapenemase inhibitors. And β-lactamase inhibitor protein can competitively inhibits Klebsiella pneumoniae carbapenemases. The movement patterns of complex involved in Klebsiella pneumoniae carbapenemase and β-lactamase inhibitor protein are analyzed by coarse-grained models. The results indicate the movement patterns of Klebsiella pneumoniae carbapenemase change a lot after it is inhibited by β-lactamase inhibitor protein. Finally, the binding modes between the series of cyclic boronic acid β-lactamase inhibitors and Klebsiella pneumoniae carbapenemase are released by molecular docking and molecular dynamics simulation, and explained the relationship between the recognition mechanism and conformation-inhibition activity of these inhibitors from the angle of hydrogen bonds and energy. This research provides a theoretical basis of the subsequent design of the inhibitor based on the Klebsiella pneumoniae carbapenemase structure.

    • Optimization experiment study on Zinc oxide ore leaching zinc

      HUANG Ping, LI Lai-Cai, ZHANG Yuan

      2017,54(3):595-599

      Abstract:

      Abstract:Using Response Surface Methodology(RSM), selecting Quadratic model, on the basis of model Box-Behnken experiment design optimization in NH3-(NH4)2SO4-H2O system leaching of zinc oxide ore experiment process parameters, and the regression equation is established.Regression analysis model of "Prob>F" value of 0.0023, less than 0.05, the model of high precision, all between independent variable and dependent variable of the regression equation is significant, regression equation to be trusted. Model analysis found that the liquid-solid ratio, leaching temperature, leaching time, the three factors that affect the leaching rate of zinc is significant, the analysis of the response surface and contour plot, liquid-solid ratio and the leaching time of interaction is significant.RSM analysis ,the optimum leaching conditions were obtained as follows: liquid-solid ratio 12.81, leaching temperature 30 ℃, leaching time of 4.15 h, total ammonia concentration of 7.5 mol•L-1, predicting leaching rate was 86.2%.Considering the feasibility of the operation, in the NH3-(NH4)2SO4-H2O system leaching process of zinc oxide ore, selected liquid-solid ratio 13, leaching time 4h, leaching temperature 30 ℃, total ammonia concentration of 7.5 mol•L-1, measured the leaching rate was 86.0%, compared with the theoretical prediction error is 0.23%.

    • Effect of Polyvinyl Alcohol on Pyrolysis of Briquette

      CUI Shuai, LV Wu-Hua

      2017,54(6):1269-1274

      Abstract:

      The influence of PVA on the pyrolysis was studied from macro and micro angles. In this paper, briquette pyrolysis was operated with thermal analyzer. The experimental data showed that with the increase of PVA content, the R value, the reaction rate and the low calorific value increased. The FTIR spectrum, BET, industrial analysis and quantum chemical analysis were described that the addition of PVA was advantage to briquette pyrolysis. The number of micropores was increased and the heat and mass transferation was improved among the fuel layer with the addition of PVA.

    • Study on Aqueous Two-phase Extraction of Salidroside

      GUO Qing-Feng, WANG Feng-Wei, CHEN Dong-Hui, WANG Dao-Wu

      2016,53(2):403-408

      Abstract:

      Based on aqueous two-phase system of polyethylene glycol (PEG)/salt, a simple pretreatment approach was developed for the extraction and determination of salidroside in Rhodiola. The influence factors on phase behavior of forming biphasic and partition behavior of the ATPS was investigated. Studied the factors such as polyethylene glycol (PEG) molecular weight and the mass fraction, the kinds of salt, the salt mass fraction, ionic strength, salidroside initial concentration influence on salidroside extraction rate. Determine the optimum extraction conditions with orthogonal experiment, when the aqueous two-phase system is 20%PEG1000, 20% (NH4)2SO4 and 1% KCl, the extracting effect is best; the extracting rate is 95.32%.Compared with the conventional liquid–liquid extraction or solid-phase extraction, this method was more environmentally, more cost effective.

    • Study on the adsorption of rare earth metal cerium ions (IV) by pectin

      ZHANG Li-Yuan, CHEN Qi, Liu Yi-wu, ZHOU Da-Li

      2017,54(4):807-814

      Abstract:

      The adsorption of rare earth metal cerium ions by low fat pectin was determined. The effects of the adsorption time, pH of the cerium ion solution, adsorption temperature, dosage of pectin and concentration of cerium ions on the adsorption capacity of pectin were investigated. The adsorption process was analyzed by the Langmuir and Freundlich models. Using the adsorption isotherm, the related thermodynamic and kinetic parameters were calculated, and infrared spectrum analysis was performed. The results indicate that the variables studied significantly affect the adsorption of cerium ions by pectin and that the infrared spectra before and after adsorption are apparently different, implying that a chemical reaction may have occurred in the adsorption process. The Freundlich equation is better suited to describe the adsorption process compared to the Langmuir equation. The adsorption process is best described by a pseudo-first order kinetics equation. Enthalpy and entropy differences are the driving forces of the adsorption process.

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    Invited Articles
    • Spatial and temporal analysis on public opinion evolution of epidemic situation about novel coronavirus pneumonia based on micro blog data

      CHEN Xing Shu, CHANG Tian You, WANG Hai Zhou, ZHAO Zhi Long, ZHANG Jie

      2020,57(2):409-416

      Abstract:

      Relying on 60 thousand blogs and 15 thousand hot blog reviews in Sina micro-blog from January 1st to February 29th in 2020, this article launches the analysis of the public opinion to the topic about novel coronavirus pneumonia based on distributed crawler technology, distributed database system, SnowNLP sentiment analysis model and K-Means algorithm. This analysis can show visually the spatial and temporal evolution process of Internet public opinion in the events of this epidemic situation. On spatial dimension, the netizens' attitude towards this pneumonia epidemic has roughly gone through three periods. The first period appears in the shape of bigger fluctuation which presents as tension and anxiety. The second period appears in the shape of rising slowly which presents as unity and excitement. The third period appears in the shape of slight fluctuation which presents as confidence and stability. On the whole, it shows the emotional state that positive is greater than negative and Optimism is greater than pessimism. On spatial dimension, we find that the area which has the most serious epidemic has the most comments and the lowest emotional value through geographical statistical analysis.

    • Computational Jurisprudence: An emerging interdisciplinary branch

      ZHANG Ni, PU Yi-Fei

      2019,56(6):1187-1192

      Abstract:

      The application of state-of-the-art artificial intelligence to the law has led to a promising area of interdisciplinary research: computational jurisprudence. By investigating legal relationships through simulation and modeling with transforming the legal information analysis to real-time online intelligent system, computational jurisprudence is not simply to simulate the methods of natural science, but a deep integration of computational thinking and legal thought. With distributed real-time computing, computational jurisprudence aims to reveal the intrinsic essence behind legal system to improve the judicial efficiency, promote legislative feasibility and also reduce the conflicts in legal system.

    • Evolvement from Jurimetrics, computational law to cognitive law

      ZHANG Ni, PU Yi-Fei

      2021,58(2):020001

      Abstract:

      The paper discusses the impact of natural sciences such as artificial intelligence technology to Jurimetrics, computational law (or computational jurisprudence) and cognitive law (or cognitive jurisprudence) from the perspective of technological development and interdisciplinary. It first proposes the theory and definition of cognitive law, including its research scope, studying meanings and academic discipline, and teases out the relationships among Jurimetrics, computational law and cognitive law. To reduce the subjectivity and provide the objective reference for the vague expression in legal system, some quantitative methods, computational intelligence and cognitive intelligence are applied to legal system successively. However, legal information is open textured and semantic vagueness, and it is difficult to express all kinds of tacit knowledge, process knowledge and fuzzy knowledge by computer symbol system. Cognitive intelligence stresses to improve the ability of intelligent systems to understand data, express knowledge, reason logically and learn by themselves. Following the footsteps of technology, it will be the inevitable trend stepping from Jurimetrics and computational law to cognitive law. Cognitive law improves the understanding of legal rules and analysis of legal behavior, and enhances the interpretability of intelligent judgments by utilizing cognitive intelligence. As the sub-branch of cognitive social science, cognitive law will improve traditional legal theories, promote the deeply integration of the Common law system and the civil law system, and is expected to be a new interdisciplinary subject.

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    Material Science
    • Study on uranium extraction from seawater with chitosan modified materials

      DONG Hao, WEN Jun, LU Xi-Rui

      2020,57(1):163-168

      Abstract:

      A novel chitosan modified material, CTS-AM-AO-DA was synthesized through the crosslinking of chitosan with amidoxime group and (1-(dimethylamino)allyl) phosphonic acid (DMAAPA) as the uranium adsorbent from seawater. The chemical structures and appearance of the polymers were characterized by the FT-IR spectrum and the SEM. The adsorption kinetics in simulated seawater and the effects of solution pH, salinity, and competing ions on the adsorption properties of materials were studied by using adsorption experiments. The equilibrium adsorption capacity of CTS-AM-AO-DA is 223 mg/g and the adsorption dynamic data are applicable to the quasi-second-order model. Weak alkalinity (8.0), high salinity (0.5 mol/L) or the presence of competitive ions (Ca2+, Mg2+, V5+) can not affect the adsorption properties of this material (CTS-AM-AO-DA) that provides the potential applications in real seawater environment.

    • Preparation and near infrared absorbing property of polyaniline/CuS composites

      LEI Qin, WEI Hai-Bo, HUANG Yong, FAN Jun-Long, XU Guang-Liang

      2020,57(1):157-162

      Abstract:

      In this work, the flower-like CuS was prepared by solvothermal method using CuSO4∙5H2O and S. The parameters, such as the mass of PVP, the mole ratio of Cu and S, the reaction time and the temperature, were carefully investigated by using the orthogonal matrix experimental method. Then, polyaniline/CuS composites were synthesized by in-situ polymerization and recombination method. The flower-like CuS was characterized by FT-IR, XRD and SEM. The near infrared absorbing capacity was test by Solid-state Diffuse Reflectance UV-Vis-NIR Spectra. The results indicate that the flower-like CuS with the diameter of 5~8 μm can be obtained under the best conditions for the mole ratio (Cu:S) of 1:2, the reaction temperature of 200 oC, the reaction time of 6 h and the mass of PVP of 0.25 g. The near infrared absorbing capacity of polyaniline/CuS composite adding 30 wt% CuS can achieve 2.1 a.u at 650 nm.

    • Absorption and scattering properties of gold nanotubes with an offset core

      ZHANG Xing-Fang, LIU Feng-Shou, YAN Xin, WEI De-Quan

      2018,55(1):0154-0158

      Abstract:

      The effects of core offset, dielectric constants of core and embedding medium as well as incident light direction on the absorption and scattering properties of gold nanotubes with a nonconcentric core are theoretically studied by the finite difference time domain method. The numerical results show that the absorption and scattering spetra red shift and the absorption-scattering ratio increases with increasing core offset distant of the inner core from the nanotube centre. Moreover, the absorption-scattering ratio also increases with the increased core dielectric constant or the decreased dielectric constant of embedding medium. When the incident light direction is parallel to core offset direction, the greater absorption-scattering ratio appears as the position of the core is close to the incident light, but the ratio is smaller than that one when the incident light direction is perpendicular to offset direction as the core offest is given.

    • g-C3N4 and P25 organic-inorganic composite for improved visible light-induced photocatalytic conversion of CO2

      WAN Li-Juan, YANG Ming

      2017,54(3):605-610

      Abstract:

      g-C3N4 and P25 organic-inorganic composite with varying the content of g-C3N4 has been synthesized through facile mixing and heating method. The composite was characterized by X-ray diffraction, high-resolution transmission electron microscopy (HRTEM) and UV-vis diffuse reflection spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and BET surface area measurements. The activity of composite photocatalyst g-C3N4-P25 with 60% or 80% g-C3N4 for photoreduction of CO2 is higher than that of either single-phase g-C3N4 or P25 under visible light irradiation. The as-prepared organic-inorganic composite exhibits an improved photocatalytic activity due to enhancement of electron–hole separations both at the interface and in the semiconductors.

    • Effect of temperature and He cumulative damage on Er2O3 film phase structure and crystallinity

      SHI Yun-Long, LAO Yuan-Xia, WANG Ling, ZHANG Hai-Bing, DENG Ai-Hong, WANG Yuan

      2016,53(6):1340-1344

      Abstract:

      In this paper, Er2O3 films are prepared in mixing atmosphere by radio frequency magnetron sputtering method. The phase structures, surface and cross-section morphologies of Er2O3films are characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The results show that the phase structure of the pure Er2O3 film is still stable under the annealed temperature of 500℃. However, with the annealing temperature increasing, the monoclinic phase of the Er2O3 film can transform into cubic phase at 700℃. In addition, for the Er2O3 film with He containing, the degree of crystallinity may be affected by He atoms. He bubbles can not be formed with small amount of He doped in, and the diffraction peak of the Er2O3 film decreased obviously comparing with that of the pure Er2O3 film. As the content of the doped He atoms increase, the monoclinic phase of the Er2O3 film becomes more stable under the high internal pressure due to the forming of He bubbles.

    • Preparation and Characterization of V- doped Titanium Dioxide Films used for Dye-sensitized Solar Cell

      LAI Qi, LIAO Xian-Jie, ZHANG Shu-Li, LI Jun-Han, WU En-Hui, ZHANG Can-Yu

      2017,54(6):1289-1294

      Abstract:

      In order to obtain high-performance batteries with titanium dioxide films by RF magnetron sputtering, doped(V2O5) TiO2 films were prepared. The main factors affecting the time,the pressure ratio of argon and oxygen, and annealing temperature. The effects such as mass of doping (V2O5) and annealing temperature on film properties.722 spectrophotometer using the optical properties of the study by the degradation of methylene blue and drop contact angle method on the catalytic properties of thin films and hydrophilic properties were studied. The results showed that Doped (V2O5) red shift the absorption peak of the film and the band gap narrowing, of which 0.5% V2O5 doped TiO2 thin film of the red shifts of the largest band gap becomes 2.88eV; 400℃ annealed films with good photocatalytic properties and ultra-hydrophilic.The prepared thin films of titanium dioxide as DSSC cells of sputtering time, the doping effect on battery performance. it shows that Doped with 0.5% V2O5 thin film battery open circuit voltage and short circuit current is higher than the undoped cell, in particular, short-circuit current increases from 24.82A to 88.15A.

    • Preparation of hydrophobic Humic Acid Ester Ether (HAEE) and its mechanisms of the remediation for chlornitrofen

      MA Chong-Di, LIU Qian, LI Yue, SHEN Yue-Yue, ZHAO Shi-Lin

      2017,54(4):822-827

      Abstract:

      Chlornitrofen is a diphenyl ether herbicide, which is a typical persistent organic pollutant and has been widely used in 70~90 years in twentieth Century. Although it has been banned for 20 years, chlornitrofen still exists in water and soil systems, which has the potential threats to the agro-ecology systems. In the present study, humic acid ester ether (HAEE) was synthesized via regulating the dosage of glycerol triglycidyl ether while humic acid ester (HAE) was uniting as raw material. HAEE was analyzed by the analysis methods of Fourier transform infrared spectroscopy and contact angles. The results indicated that hydrophobic HAEE has the structure of humic acid and the characteristic functional groups of HAE. The adsorption characteristics and mechanisms of HAEE to chlornitrofen were investigated via a series of batch equilibrium experiments. As the results showed, the hydrophobic angle is increased from 30 to 96 degrees before modification. The degree of hydrophobic of HAEE is positively correlated with the adsorption capacity of chlornitrofen, and equilibrium reached after 2.0 h. The kinetics of adsorption is described well by the pseudo-second-order model, and Freundlich models are more suitable for the sorption isotherm. The adsorption capacity reduces gradually after 5 cycles. The removal rate is still above 78%. The adsorption mechanisms are π-π interaction and hydrophobic distributional effects. Adsorbent prepared by this method may provide a novel approach for remediation of chlornitrofen in aqueous-soil environment.

    • The magnetic model of the superparamagnetic magnetite magnetoreception

      QIAN Xia

      2017,54(6):1295-1300

      Abstract:

      The model of biomagnetite magnetoreceptions include the model of single-domain magnetite magnetoreception and the model of superparamagnetic magnetite magnetoreception. In honeybees, there are many typical superparamagnetic magnetites, so in this paper, the magnetic model and working mechanism of the superparamagnetic magnetite magnetoreception are discussed qualitatively from the point of view of theory of magnetism taking the example of honeybees. In the outer magnetic field, each superparamagnetic magnetite can be act on with the size extend or contract along different directions. Superparamagnetic magnetites transmit the force and change of size to the outer biomembrane and eukaryotic cytoskeleton which embedding in the nervous system, so a nerve signal can be produced. The signals can be magnified because many superparamagnetic magnetites exist.

    • Preparation and Adsorption Performance of Porous Ceramic-based Lithium Ion Adsorbent

      ZHANG Li-Yuan, YANG Dong-Rui, ZHOU Da-Li

      2017,54(3):611-616

      Abstract:

      Li4Ti5O12 was synthesized by the sol-gel process under different conditions, and the as-prepared products were characterized by XRD in order to find out the ideal condition of preparing Li4Ti5O12. The precursor sol was loaded on porous ceramics synthesized from kaolin, talcum powder, alumina and carbon powder, and then Li4Ti5O12 based on porous ceramics was prepared after drying and calcination. Subsequently, porous ceramic-based lithium ion adsorbent was obtained by modification with hydrochloric acid, and then adsorptive capacity of the obtained product was measured. The results indicate that increasing calcination temperature and holding time is beneficial to the formation of Li4Ti5O12. The products with good crystallinity and purified crystal phase are obtained after a calcination at 750 ~ 800 ℃ for 5 ~ 8 h. The extraction rate of Li+ from Li4Ti5O12 and the adsorptive capacity are increased with the increment of calcination temperature and holding time. The Li+ drawn out ratio of the products calcined at 800 ℃ for 5 h is 51.7 %, and the adsorptive capacity reaches 12.2 mg Li+/g Li4Ti5O12.

    • Synthesis of photocatalytic Er3+:Y3Al5O12/ZnO and Research its Photocatalytic activity

      DING Yong-Ping, LIU Wen-Fang, GUO Yu-Wei

      2017,54(1):141-146

      Abstract:

      An upconversion luminescence agent Er3+:Y3Al5O12 mixed with the ZnO that utilizing visible light was synthesized by using sol-gel method and the hydrothermal method,and it was charactered by XRD and SEM. Based on the methyl orange, the photocatalytic activity of the Er3+:Y3Al5O12 mixed with the ZnO was researched under the visible light irradiation. In addition, the influence of the calcine temperature、calcine time、the visible light irradiation time and intensity、the dye initial concentration and the amount of catalyst on the degradation rate of the methyl orange were investigated. The results revealed that the degradation rate increased significantly by adding upconversion luminescence agent Er3+:Y3Al5O12 , and the degradation rate was the best when the 10% of the amount of catalyst .

    • The synthesis of ZnTiO3/TiO2 composite photocatalysts and their photocatalytic performances

      LIU Leng, DU Yi-En, LI Jun, LIU Yu-Fang, CAI Xue-Mei, CHEN Yong-Qiang

      2018,55(4):827-832

      Abstract:

      The ZnTiO3/TiO2 composite photocatalysts with high photocatalytic activity were synthesized by hydrothermal treatment of the [Ti4O9]2ˉ nanosheets after it was adjusted to a desired pH value with a 3 mol/L HCl solution and a 3 mol/L NaOH solution in the present of hexamethylenetetramine and Zn(NO3)2. The [Ti4O9]2ˉ nanosheets were prepared by using the layered tetratitanate K2Ti4O9 as the processor. First, the K2Ti4O9 sample was converted into a protonic tetratitanate H2Ti4O9 by exchanging K+ of K2Ti4O9. And then the H2Ti4O9 was mixed with the triethanolamine (TEAOH) to obtain the TEA+-intercalated tetratitanate compound. Finally, the TEA+-intercalated tetratitanate compound was dispersed in massive amounts of distilled water to obtain the [Ti4O9]2ˉ nanosheets. The structures and morphologies of the ZnTiO3/TiO2 composite photocatalysts were investigated by using X-ray diffraction (XRD) and scanning electron diffraction microscopy (SEM). Furthermore, the photocatalytic activities of the synthesized ZnTiO3/TiO2 composite photocatalysts were also characterized. The experimental results revealed that the ZnTiO3/TiO2 composite photocatalyst obtained at the value of pH = 7.0 exhibits the higher photocatalytic activity.

    • Microstructure evolution on tensile of tungsten nanowires with different crystal orientations of [110], [112] and [111]

      LU Min, YU Dong-Hai, LIU Chang-Ju

      2017,54(1):147-155

      Abstract:

      Mechanical properties and micro-structure fracture mechanism of tungsten nanowires with crystal orientation of [110],[112] and [111] have been investigated with molecular dynamics and embedded atom methods. Simultaneously common neighbor analysis, center symmetry parameters and coordination number has been employed to analysis the evolution of structure. It is concluded that different crystal orientation nanowires have different characters. The elastic modulus, yield strain, yield strength and the fracture stress is decreasing in the sequence of[111], [110]and [112] crystal orientations. It also reveal that all of the stress-strain curves are classified into four stages: elastic stage, damage stage, yielding stage and failure stage. It concluded that crystal orientation has slightly impact on the elastic modulus but has great effect on tensile strength, yield strength and ductility. Interestingly, hardening stage has been found in tungsten nanowire with crystal orientation of [112] at yielding stage. That is to say the strain increase with the stess increase in the hardening stage, the nanowire with crystal orientation of [112] has the trend that recover its capability in strength, but consequently result in the least ductility. In the end the tensile failure mechanisms of the three nanowires have been summarized.

    • Study on the Supercapacitance Performance of Graphene Oxide-pristine SWNT composites

      CHEN Jian-Yu

      2017,54(1):156-160

      Abstract:

      Graphene Oxide-Pristine SWNT composites were fabricated using graphene oxide(GO) as a surfactant to directly disperse pristine SWNT, followed by a freeze-drying method of the sample. The morphology, structure, component and electrochemical property of the compounds were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and electrochemical measurements. The results showed that the electrochemical properties of the compounds were significantly improved due to the insertion of SWNTs into a GO matrix. Through changing the ratio between SWNTs and graphene oxide, the sample corresponding to a SWNT ratio of 10% showed the best supercapacitor property. At such a optimized mixing ratio, the specific capacitance of the nanocomposite was 155 F·g-1 at a current of 0.5A·g-1 in the KOH aqueous electrolyte of 6 mol·L-1 , which was 1.9-fold higher than that of pure graphene oxide (81.5F·g-1). These results clearly demonstrate that GO-SWNT composites prepared by our present simple method is very promising for next generation high-performance energy storage devices.

    • Synthesis of Fe2O3 photoanode with improved photoelectrochemical performance by surface electrochemical pretreatment and Ti-doping

      WAN Li-Juan, ZHANG Li, YANG Ming

      2018,55(5):1083-1090

      Abstract:

      Ti-doped Fe2O3 photoanode was obtained through metal–organic decomposition method. The physical and photophysical properties of the hematite photoanode were investigated by X-ray diffraction (XRD), UV-vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) and the photo-electrochemical performance was evaluated for the Ti-doped Fe2O3 photoanode. In terms of maximizing the photoelectrochemical performances of the Ti-doped Fe2O3 photoanodes, the doping concentration of titanium was optimized. The Ti-doped Fe2O3 photoanode exhibits improved photoelectrochemical performance after the electrochemical surface pretreatment. The photoelctrochemical response of hematite photoanode can be improved by both titanium doping and the electrochemical surface pretreatment. Based on the analysis of the Mott–Schottky plots and electrochemical impedance spectra (EIS), a possible mechanism was proposed to explain the reason for the enhancement of photocurrent.

    • Preparation and photocatalytic properties of Zn2+/nano MoS2 intercalation compounds

      CHEN Dong-Xun, LIU Yong-Gang, XIE Zhu-Lu, LUO Zhi-Hao

      2018,55(4):838-842

      Abstract:

      In order to improve the photocatalytic performance of molybdenum disulfide,Zn2+/nano-molybdenum disulfide intercalation composite catalyst was prepared by stripping-intercalation-re-stacking method. The microstructures of the composite catalysts were analyzed by SEM,UV-Vis and XRD; The performance of composite catalyst for catalytic degradation of methyl orange in sunlight was also studied.The results show that the prepared Zn2+/ nano - molybdenum disulfide intercalation composite catalyst has a good crystal form, the interlayer spacing increases to 4.3934 nm, the particle size increases to 13.1 nm, and a new intercalation characteristic peak (001) appears. The prepared composite catalyst has a lamellar structure, and the non - uniform loading of Zn2 + nanoparticles is on the surface of molybdenum disulfide nanosheets and is mainly distributed in the smaller regions of the lamellae. The absorption of UV-Visible light is obviously higher than that of molybdenum disulfide powder and has the absorption peak. It is proved that the catalytic performance of the composite catalyst in the sunlight is much higher than that of the nanometer MoS2 powder from the beginning, and the degradation efficiency is linear and can reach 70.435% at 6h.

    • Study on the mixing process of U-Mo microspheres and Al powders

      YU Zheng-Wei, WANG Lu-Quan, LIU Hai, LENG Mao-Lin, HUANG Jian-Min, GUO Zhen

      2017,54(2):371-375

      Abstract:

      U-Mo microspheres and Al powders were mixed by vertical planetary pot-classifying mixer. The influences of mixing time, mixing speed and filling rate on the mixing degree of mixed powders were studied systematically. The orthogonal experiment is designed to analyze the influence degree of the three factors on the mixing degree. The mixing degree and microstructure were discussed by variation coefficient method and stereomicroscope, respectively. Results show that optimal mixing process parameters: the mixing time of 90min, the mixing speed of 30r/min and the filling rate of 30%. The optimal mixed powders have a mixing degree of 93.6%. Three kinds of mixed factors impacting on the mixing degree have the order: mixing time < filling rate < mixing speed.

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    Chemistry and Material Science
    • Quantitative detection of several heavy metals by modified surface enhanced Raman substrate

      TAN Xiong, LIU Xian-Bo, BAI Hong-Jie, CUI Xu-Dong, LIU Tong

      2021,58(1):015002

      Abstract:

      Heavy metal ions have a serious impact on water quality and its application, and the development of a highly selective and sensitive detection platform for heavy metal ions has great significance in the water resources protection. The surface-enhanced Raman (SERS) sol substrate was prepared by using 4-MBA to modified gold nanoparticles as a carrier, which has strong selectivity and high sensitivity to heavy metal ions such as Pb2+, Cd2+, and As3+ in aqueous solution. The experiments found that the Raman detection spectra of Pb2+, Cd2+ and As3+ by the SERS substrate have obvious shifts in vibration frequency bands and peak intensities near 1046cm-1, 1075cm-1, and 1587cm-1. An optimized enhanced substrate was obtained by optimizing the sol-substrate, which can distinguish three kinds of heavy metal ions. The detection limit for heavy metal ions can reach 0.1mg/L, and it has a linear relationship in the range of 0.5 to 100 mg/L. A standard addition verification experiment was performed on Pb2+ in real water samples. This substrate provides a fast and convenient method for heavy metal identification and detection with better enhancement effect and heavy metal quantitative analysis ability, and provides an effective means for the efficient detection of heavy metal ions in water.

    • Microstructures and hot compression behavior of Mg-4Sn-1Ce alloy

      WU Ying, ZENG Qiang, HU Guang-Shan, WEN Tong

      2021,58(1):015001

      Abstract:

      The microstructures and hot compression behavior of Mg-4Sn-1Ce alloy were studied by optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and hot simulation test. The results shown that the as-cast alloy is mainly composed of island-like “island” shaped α-Mg、Mg2Sn、Ce4Sn5 and MgSnCe phases with the strain rate range of 0.001~1 s-1 and temperature range of 250~450 ℃ hot compression. The hot deformation activation energy Q is 162.03 kJ/mol. When the hot compression temperature increases from 250 to 450 ℃, the microstructures of tested alloy evolve from (compressed grains+extruded streamlines) to recrystallized equiaxed grains.

    • Graphene-CsPbBr3 quantum dots photodetectors with high responsivity

      WANG Jing, SHI Rui-Ying, ZHU Guo-Dong

      2021,58(2):025001

      Abstract:

      All-inorganic perovskites, such as CsPbX3 (X = Cl, Br, I), are gaining increasing attention due to their outstanding optoelectronic properties, especially their higher thermal stability comparing with organic-inorganic hybrid perovskites. However, CsPbX3-based photodetector demonstrated a relatively low responsivity due to the low carrier mobility of perovskite films. In this work, we synthesize CsPbBr3 quantum dots and construct a hybrid graphene-CsPbBr3 quantum dots photodetector with a responsivity of 3.5×104 A W-1, by introducing graphene as a transport layer. The unprecedented performance is attributed to the effective charge transfer and photogating effect, high mobility of graphene and prolonged carrier lifetime.

    • Numerical simulation of biomass grate furnace combustion based on FLIC

      XIAO Fan, HU Nan, ZHANG Man, JIN Yan, YANG Hai-Rui

      2021,58(2):025002

      Abstract:

      Based on the FLIC simulation platform, we have performed a numerical simulation study on a 7 MW biomass layer fired hot air boiler in Northeast China. The simulation results show that the biomass layer can be roughly divided into three stages, the water evaporation section (0~0.5 m), the volatile emission combustion section (0.5~2.1 m) and the fixed carbon combustion section (1.0~2.8 m). The volatile content of this fuel is relatively high, the thickness of the bed after its precipitation is significantly reduced, and the primary air temperature is too low, resulting in a low fixed carbon burnout rate, so the primary air temperature can be appropriately increased. According to the characteristics of the fuel in different combustion stages, the air can be supplied on demand. For example, 80% to 90% of the total volume can be provided during the volatiles escape combustion stage, and 10% to 20% of the total air can be provided during the fixed carbon combustion stage. This improves the fuel combustion efficiency, and can optimize the structure of the arch angle and the furnace arch coverage length according to the flue gas temperature, and enhance the ignition and burnout of the furnace arch. According to the simulation results, it is proposed to optimize the primary air and the air supply scheme to make the combustion more adequate.

    • The effect of high temperature treatment on the structure of sodium bentonite montmorillonite

      QIN Ya-Ting, PENG Tong-Jiang, SUN Hong-Juan, ZHOU Can, CHAO Li

      2021,58(3):035002

      Abstract:

      The bentonite from Wuhu, Anhui (WH), Santai, Sichuan (ST), and Xinyang, Henan (XY) were used as the raw material, and sodium carbonate was used as a modifying agent to modify three raw materials (named as WH-G, XY-G and ST-G), then the sodium samples were heat-treated at high temperature. The phase, structure, thermal properties and spectral characteristics of samples were characterized and analyzed. The results showed that the temperature of the montmorillonite losing adsorbed water and interlayer water in the three samples WH-G, XY-G and ST-G increase with the increase of the layer charge number of the montmorillonite in the samples, but its thermal stability is opposite. The structures of montmorillonite WH-G and XY-G samples are completely destroyed at 900 °C, while the structure of montmorillonite of ST-G sample is completely destroyed at 800 °C.

    • Simulation and performance study on the four type substrates of domestic thick gaseous electron multiplier

      YAN Jia-Qing, XIE Yu-Guang, DENG Shan-Qiao, ZHEN Zhi-Yang

      2021,58(5):055001

      Abstract:

      Ceramic-based Thick Gaseous Electron Multipliers (THGEMs) have been successfully applied to neutron detection. The influences of ceramic, FR4, kapton, and PTFE substrates on the thermal neutron scattering and absorption were studied and compared by Geant4 software. The ceramic-THGEMs, FR4-THGEMs, kapton-THGEMs and PTFE-THGEMs are homemade in PCB factory, which have the same geometric parameters such as aperture of 200 μm, hole spacing of 600 μm, thickness of 200 μm, insulation ring width of 80 μm, and sensitive area of 50 mm × 50 mm. The gas gain, energy resolution and gain stability were measured using 5.9 keV X-rays, four different type substrates THGEM can work normally. The maximum gain of a single and double layer ceramic THGEMs reach 1.2×104 and 4×104 in Ar + CO2 =80:20, respectively. The energy resolution is better than 24.4% in Ar + iC4H10 = 97:3. Good gain stability was obtained during a more than 100 hours continuous test. By using a 239Pu source, the alpha deposited energy spectrum and gain curve of the ceramic THGEM were measured.

    • First-principles study of the properties of Au-Ag nanotube encapsulated into carbon nanotube

      SUN Ya-Ru, MA Liang-Cai

      2021,58(3):035001

      Abstract:

      By using first-principles calculation based on density-functional theory, we have systematically investigated the stability, electronic and mechanical properties of (4, 2) Au-Ag alloy nanotubes encapsulated in a series of zigzag (n, 0) carbon nanotubes with various diameters. The most stable combined system with larger filling rate is AuxAg4-x@(15, 0) with an optimal tube-tube distance of about 4.20 ?. The analysis of band structure shows that the quantum conductance of the composite system is much higher than that of the corresponding isolated alloy nanotubes. The energy states near the Fermi level are mainly attributed to the s electrons of the inner Au and Ag atoms as well as the p electrons of the outer C atoms. The critical strains and the ideal strengths of the combined systems are remarkably higher than those of the freestanding alloy nanotubes, suggesting that the mechanical properties of the alloy nanotubes are signi?cantly enhanced by the carbon nanotube coating.

    • Research on pesticide treatment efficiency of constructed wetland-microbial fuel cell coupling system

      JIANG Song-He, PIAO Wen-Hua, JIN Ming-Ji

      2021,58(6):065001

      Abstract:

      In this study, a constructed wetland-microbial fuel cell system was constructed to treat pesticides represented by Atrazine, and to understand the pesticide treatment efficiency and treatment mechanism of the system. The results show that the system has a good treatment performance for Atrazine. When the concentration of Atrazine is less than 4 mg/L, the treatment performance of the system remains stable above 85%. Under the condition of Atrazine concentration of 4 mg/L, the system has the best power generation performance. At this time, the average daily voltage, maximum power density and current density of the system output are 284.4 mV, 19.64 mW/m3 and 46.09 mA/m3, respectively. Pesticides have a significant impact on the microbial diversity of the system, but have no significant impact on microbial gene function, and have less impact on system bacteria than the electric field. The dominant bacteria phylum of the system includes the Proteobacteria, and the dominant electrochemically active bacteria includes the Bacteroides and Firmicutes, while the dominant bacteria phylum degrading pesticides includes the Actinobacteria, the dominant bacteria classes includes Alphaproteobacteria and Actinobacteria, and the dominant bacteria genus includes Christensenellaceae_R-7_group.

    • Synergistic tuning of microstructure and thermoelectric performance of bismuth telluride based materials by ball milling

      LIU Sheng-Cun, CHEN Long, WANG Zheng-Shang

      2021,58(5):055002

      Abstract:

      Bismuth telluride compounds are thermoelectric materials with the best performance near room temperature, which have important application value in waste heat recovery and solid state refrigeration. The main preparation method is ball grind milling, and slight changes of various parameters may affect the microstructure and thermoelectric properties of materials. Ball milling time, as an important ball grinding parameter, can not only affect the refinement of powder particle size, but also regulate the thermoelectric properties of materials. Therefore, it is urgent to analyze the influence of ball milling time on the crystal structure, particle size and the thermoelectric performance of products. In this paper, bismuth telluride compounds were prepared by adjusting different ball milling time with constant ball grinding speed. The response of grains to ball milling time is found through the analysis of crystal structure and powder particle size. The result of subsequent thermoelectric performance tests shows that, with the increase of ball milling time, the change of particle size leads to the synergistic tuning of electron and phonon transport. Finally, the maximum ZT merit of n-type and p-type bismuth telluride were increased to 0.91 and 1.11, respectively. This study systematically summarizes the influence of ball milling time on the microstructure and the thermoelectric capability of bismuth telluride. Our work shows the significance in the mergence of powder metallurgy and thermoelectrics, which may play some roles in the commercial application of thermoelectric conversion technology.

    • Preparation of a novel chitosan magnetic material and its adsorption mechanism towards dyes

      TIAN Tian, ZHANG Ling-Lin

      2021,58(4):045002

      Abstract:

      In order to effectively solve the environmental pollution caused by dye wastewater, a copper ion chelated chitosan magnetic composite was prepared for the adsorption of dye wastewater. The composite Cu@CTS@Fe3O4 was successfully prepared by the coordination chelation of chitosan with copper ion and the introduction of magnetic particles Fe3O4. The structure and morphology of the prepared materials were characterized by FTIR, SEM and TGA. At the same time, the adsorption kinetics and isotherm adsorption of reactive brilliant red (RBR) were studied in detail. The adsorption experiments showed that the adsorption capacity of Cu@CTS@ Fe3O4 to RBR reached the maximum of 831.22 mg/g when pH=2. This study provides some relevant data and theoretical guidance for the application of chitosan-based adsorbents in the field of dye wastewater treatment.

    • Study on the evolution and protection of decarburization in 300M steel

      WEI Ming-Gang, LUO Heng-Jun, ZHANG Hai-Cheng, DENG Hao, Lü Xiao-Gen, CHEN Long-Qing, TANG Jun, XIE Jing

      2021,58(6):065002

      Abstract:

      300M steel is an important material for fabricating main bearing structure of aircrafts. However, the surface oxidation and decarburization of this material will occur in varying degrees during the heat treatment of die forging process, which seriously affects the yield of forgings. Herein, the decarburization behavior of 300M steel under different heat treatment conditions is systematically studied. The morphology and thickness of the oxide layer are analyzed by scanning electron microscope (SEM) and the corresponding Energy Dispersive Spectrometer (EDS). The variation of decarburization depth is measured using microhardness method. The evolution of decarburization behavior of 300M steel under different heat treatment conditions is clarified, and the effect of anti-oxidation coating on the depth of decarburization layer is presented. The results show that the dense oxide layer formed on the surface of 300M steel during heat treatment has distinct protective effect, which can prevent the matrix carbon from diffusing to the surface, thus reduce the depth of decarburization layer. There is a balance between the diffusion rate of carbon and the surface oxidation rate at different temperatures, and the application of anti-oxidant coating on the surface of 300M steel will change the original balance. The results of microstructure analysis show that the full decarburization zone on the surface of 300M steel is composed by pearlite or ferrite, and the semi-decarburization zone is mainly martensite and precipitated carbide. We also expound the evolution of the near-surface microstructure of 300M steel with the increase of holding time. Finally, the coupling mechanism of decarburization and oxidation on the surface of 300M steel is revealed from the perspective of thermodynamics. The results of this paper are expected to provide important data and theoretical support for establishing optimization process of die forging and developing heat treatment protection technology of 300M steel.

    • Determination of Maleic acid in solution and food additives by fluorescence

      YU Shan-Shan, TIAN Jun

      2022,59(1):015001

      Abstract:

      In the face of ever-increasing food safety issues, the detection of bad additives is critical. In order to achieve the effective detection of maleic acid in food additives, we propose to use compound 1 (2,2’-diformyl-1,1’-binaphthyl) to indentify maleic acid by fluorescent. The conditions of fluorescence detection are explored in detail in detail, and the results show that the best fluorescence enhancement effect is obtained in methanol. The calculations predict the low detection limit (1.3×10-7 mol/L), which indicates that it has potential application prospect. Finally, maleic acid in starchy foods was successfully detected by using this probe.

    • Influence of sulfuric acid treatment on the structure and morphology of illite and montmorillonite

      ZHOU Can, SUN Hong-Juan, PENG Tong-Jiang, ZHANG Qi

      2022,59(2):025001

      Abstract:

      In the structures of the illite and montmorillonite, because the amount of Al3+ replacing Si4+ in the tetrahedrons is different, the number of layer charge is different, and the degrees of damage to the structure during acid treatment are also different. In this work, two raw materials, Zhejiang Anji bentonite and Jilin Antu illite, were respectively acid treated with sulfuric acid and hydrogen peroxide for comparative experimental study. The phases, structures, thermal properties, spectroscopic properties and microscopic morphologies of the raw were characterized and analyzed. The results show that the montmorillonite structure of the montmorillonite sample is destroyed when the acid treatment concentration is 2 mol/L. With the increase of the acid treatment concentration, the surface of the lamellae changes from smooth and flat to edge curling to collapse between layers; The structure and morphology of illite of the sample are basically intact when the acid treatment concentration is 6 mol/L, and the acid corrosion resistance of montmorillonite is not as good as that of illite. The results in this study are of significance to the application and development of illite and montmorillonite.

    • Rapid detection of potassium sorbate by nitrogen-doped carbon quantum dots fluorescence probe

      SUN Xue-Hua, QIANG Yu, HAO Du-Ting, ZHAO Ying-Jie, ZHAO Rong-Rong

      2022,59(2):025002

      Abstract:

      Potassium sorbate is an acidic food preservative, which can effectively inhibit the activity of mold, yeast and aerobic bacteria, prolong the storage time of food, and maintain the original flavor of food. In this study, fluorescence nitrogen doped carbon quantum dots (NCQDs) with good water solubility was synthesized by one-step hydrothermal method. Based on the effective quenching of NCQDs by potassium sorbate, a fluorescence probe for rapid detection of potassium sorbate was constructed. Under the optimal experimental conditions, the concentration of potassium sorbate showed a good linear relationship with the fluorescence quenching intensity of NCQDs in the range of 3.0×10-5~ 1.0×10-4 mol/L and 1.0×10-7~3.0×10-5 mol/L, and the detection limit was 9.5×10-8 mol/L. It has been used for the determination of potassium sorbate in soda water and white vinegar with the recoveries of 98.25%~102.7% and 98.33%~101.8%.

    • Study on leaching blast furnace dust with deep eutectic solvent and electrodepositing zinc

      HUANG Ping, ZHANG Yuan, WU En-Hui, ZHANG Sheng-Qian, GUO Wen-Ming, SHI Ming-Chuan

      2022,59(1):015002

      Abstract:

      The choline chloride-urea deep eutectic solvent system was used to leach blast furnace dust, and then zinc was obtained by direct electrodeposition. The effects of liquid-solid ratio, leaching time, and stirring speed on the leaching rate of zinc were investigated. After the leaching experiment, the cyclic voltammetry and electrodeposition experiments were carried out, respectively. The experimental results showed that the leaching rate of zinc reaches 71% under the conditions of liquid-solid ratio of 10 mL/g, the leaching time of 30 h, the stirring speed of 300 r/min, and the temperature of 70 ℃. The cyclic voltammetry test confirmed that the reduction potential was -1.4 V. X-ray diffraction and energy spectrum analysis showed that the coating was metallic zinc with high purity. By analyzing the morphology of the coating, it was found that the zinc coating was composed of cluster grains of about 1 μm.

    • Efficient synthesis and antioxidation activities of ferrocenylpyrano-fused quinolines

      ZHANG Xiao-Ping, JIN Gui-Yong, MA Sheng-Tao, WANG Er-Bin, ZHAO Xue-Bin, CHEN Zhi-Fei, LI Zhuo, CHU Wen-Juan, ZHAO Xu, XI Gao-Lei

      2022,59(3):035001

      Abstract:

      Fifteen known ferrocenylpyrano-fused quinolines were synthesized efficiently via three-component Povarov reaction of 4-methyl-7-aminobenzopyranone, aromatic aldehydes, and ferrocenyl acetylene in the presence of cerium trifluoromethylsulfonate (Ce(OTf)3) and scandium trifluoromethylsulfonate (Sc(OTf)3), with yields ranging from 40.0% to 66.8%. The structures of the compounds were characterized by 1H NMR, 13C NMR, and HR-MS (ESI). The antioxidant activities of the compounds were evaluated by inhibiting oxidation reaction of DNA induced by hydroxyl radical (HO·) and reductive glutathione radical (GS·), and the effects of the type, position and number of substituents on the antioxidant abilities of ferrocenylpyrano-fused quinolines were investigated. The results showed that the fifteen target compounds exhibited strong radical scavenging activities to protect DNA against oxidation induced by HO· and GS·. The absorbance percentages of thiobarbituric acid reactive substances (TBARS) of the fifteen target compounds were 36.6%~83.3% in inhibiting HO· induced oxidation of DNA, and 22.9%~67.2% in inhibiting GS· induced oxidation of DNA, respectively. The antioxidant activity could be further enhanced by introduction of electron-donating groups (such as -N(CH3)2, -OCH3, and -OH) in ferrocenylpyrano-fused quinolines structures, while antioxidant activity was reduced when electron-withdrawing group (-Cl) was introduced. The ferrocenylpyrano-fused quinolines exhibited better antioxidant performance than ferrocenyl quinolines and are potential powerful antioxidants.

    • Adsorption of polyvinylpyrrolidone on Ag surface and mechanism of selective growth of Ag nanostructures

      LIU Bo, SUN Hong-Juan, PENG Tong-Jiang, HE Rong, ZHU Wen-Kun

      2022,59(4):045001

      Abstract:

      To elucidate the mechanism of selective growth of Ag nanowires in capping agents, we investigated and the interaction between polyvinylpyrrolidone (PVP) molecules and various Ag crystal surfaces by first-principles calculations. The results show that PVP molecules severely affect the stability of Ag surfaces. Only Ag (200) and Ag (111) facets well maintain their structures upon the absorption of PVP molecules, suggesting their preferential growth in this capping agent. With the increase of PVP concentration, the binding of PVP molecules to the Ag (200) facet becomes stronger than that of Ag (111), which may facilitate the formation of Ag (200) nanostructure. The regulation mechanism of long-chain PVP molecules on Ag (200) nanostructures is mainly governed by the van der Waals force as well as the chemical bonding between ketone oxygen and Ag atoms.

    • 3D printing of shape-controllable alumina ceramics by using optimized slurry and sintering process

      CHEN Long, WANG Zheng-Shang, CUI Xu-Dong

      2022,59(4):045003

      Abstract:

      In this work, the relationship between solid content and viscosity for light curing slurry was studied. The preparation and printing of high solid content slurry (45 vol%) were realized by regulating rheological priperties of the dispersant. It is found that the processes of degreasing and sintering are key factors and cracks, which directly affect the quality of ceramics. Thus, the degreasing curve was adjusted according to the type of organic matter in the prepared alumina ceramic slurry. In addition, the two-step degreasing methods of pyrolysis in vacuum and carbon removal in air can fully remove the organic mater, which is not easy to peroduce pores. Finally, the alumina ceramic material with the dense structure was obtained. In all, the effects of dispersant type, concentration and alumina solid content on slurry viscosity were systematically analyzed and the degreasing process was optimized. We hope our work can provied an experimental basis for the light curing molding and the perormance optimization of complex structural ceramic materials.

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    Education Teaching Reserch
    • Recognizing learners' personality traits based on programming behaviors and its application explorations

      Lin Tao, Zhou Xiaohan, Wu Zhiming, HONG Mei, WANG Jian, TANG Ning-Jiu

      2021,58(5):057002

      Abstract:

      How to perform individualized programming teaching is an important issue in educational practice, and how to recognize the personality of learners is the key for this issue. In this paper, the method of recognizing personality is proposed based on the programming behaviors of learners. Specifically, the programming behavior features of learners are first extracted from multiple aspects; then the classification models are established using the support vector machine; finally, the multi-task voting strategy is used to comprehensively identify learners' personality traits. The results show that the traits in the Big Five Model can be predicted using the proposed method, verifying the feasibility of using programming behaviors to identify learners’ personality to a certain extent; in addition, this paper also discusses the applications of the proposed method in future programming education.

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    Interdisciplinarity
    • Model and algorithm for vehicle routing problem with spatial-temporal correlated stochastic travel times

      ZHANG Dong-Qing, GUO Zhao-Xia, ZHANG Yin-Jie

      2021,58(6):067001

      Abstract:

      This paper studies a version of vehicle routing problem with spatial-temporal correlated stochastic travel times in real road networks. First,a two-stage stochastic optimization model is established for this problem. An intelligent stochastic optimization method is then proposed to solve the model, in which an efficient intelligent optimization algorithm is developed to find candidate solutions, and the scenario generation technology is adopted to generate spatial-temporal correlated stochastic travel time scenarios to evaluate the solutions. This paper proposes a hybrid particle swarm optimization algorithm combined with a variable neighbourhood descent algorithm to perform effective optimization. Finally, a series of testing instances are established based on the road network of Beijing to verify the effectiveness of the hybrid particle swarm optimization algorithm. The experimental results show that considering the spatial-temporal correlation of stochastic vehicle travel times in real traffic environment will affect the best vehicle routing decisions.

    • Research on the impact of informal governance in the innovation ecosystem on the symbiosis of system members

      GAO Jia-Xin, WANG Tao, GU Xin

      2021,58(6):067003

      Abstract:

      Informal governance can coordinate symbiotic relationships and behaviors among members, promote interdependence and interaction among members, and promote the healthy symbiotic development and value co-creation of the innovation ecosystem. Based on the social embedding theory and organizational ecology, this paper summarizes four types of informal governance: trust, reputation, cooperative culture, and joint sanctions based on existing research. Using the Logistic model, we construct a symbiosis model of the informal governance influence on the symbiosis relations evolution among members of the innovation ecosystem from the perspective of symbiosis theory, and conduct evolutionary stability analysis and simulation of the symbiosis model. The research results show that the symbiosis evolution of members of the innovation ecosystem depends on the strength of the symbiosis coefficient between members. Among them, the symbiosis coefficient of trust, reputation, and cooperative culture has a positive impact on the symbiosis evolution of system members, which is conducive to the formation of mutual symbiosis. The impact of joint sanctions on the symbiosis and evolution of system members is both positive and negative, which may produce parasitic, partial or reciprocal symbiosis. The income of the symbiosis and stable state of system members is affected by the symbiosis coefficient of informal governance and the maximum income of the main body. Informal governance affects the evolution of enterprises in the innovation ecosystem to a mutually beneficial symbiosis relationship, and provides enlightenment for the formulation of informal governance of enterprises, the realization of value co-creation and the healthy operation of cooperation and symbiosis of the innovation ecosystem.

    • Investigating the impact of risk attitude and privacy protection on consumers' data sharing behavior

      QIN Jun-Chang, WANG Yuan, DONG Yu-Cheng

      2021,58(6):067002

      Abstract:

      Promoting the sharing of big data is the key to development and prosperity of the sharing economy, and it is of great practical significance to study the influence mechanism of data sharing. Based on consumers' risk attitudes and corporate privacy protection methods, this paper constructs a game model of data sharing between enterprises and consumers, in which the mechanism that affects data sharing behavior is analyzed and specific policies are recommended. The main findings of this paper are: (1) the risk-biased consumers’ data sharing behavior is mainly affected by factors such as data leakage losses and data protection cost differences. (2) The risk aversion of risk-averse consumers is highly correlated with the game results of data sharing. For the consumers who have a moderate level of risk aversion, there are dual equilibria when the loss caused by data leakage is greater than the difference between the cost of high and low privacy data protection. (3) When the proportion of risk-biased consumers is high, the behavior of risk-averse consumers to use the high quality of sharing data will be increased, while the enterprises will reduce the high-quality protection behavior on protecting consumers' privacy.

    • Optimized Housing Price Prediction Based on XGBoost

      TAO Ran

      2022,59(3):037001

      Abstract:

      Objectively, housing prices are restricted by many factors and because of this, house price prediction remains a very classical and challenging problem in data analysis. In response to the redundancy of house price data, which makes it difficult to identify important features in practical scenarios, this paper proposes an innovative approach to data pre-processing and data prediction by means of double model iterative fitting. The initial data is pre-processed in terms of data meaning, data form and data relevance, then suitable models are selected for training. In traditional machine learning, Random Forest (RF) and XGBoost (XGB) are two commonly used methods. The RF model is able to accurately judge "redundant" features through its Bagging process. The XGB model, while improving prediction, is also limited by its reduced generalisation ability and cannot stably reflect the importance of features. Therefore, this paper uses the RF model to process redundant data and uses the XGB model to fit new data sets to improve the prediction results. In this paper, experiments were conducted on the Kaggle competition dataset ("House Prices Advanced Regression Techniques") and the test results showed that the final regression accuracy R2 of the XGB regression model was 87%, while the R2 of the single RF model and the single XGB model were 79.2% and 78.7%, respectively. The experiment proves that the data prediction method can significantly improve the effect of housing price prediction. To fully reflect the model fitting effect and prediction ability, the authors change the "house price" to discrete variable which has two categories of "high" and "low", and get the Confusion Matrix with an precision of 93% and a recall of 93%.

    • Two-period equilibrium model and pricing strategy with trade-in for duopoly

      LI Hui-Zhong, YIN Yi-Xi, PANG Qi, WU Peng

      2022,59(3):037002

      Abstract:

      Trade-in is a popular marketing method in the current age, making enterprises face new challenges in market competition. This study sets up a two-period duopoly model with differentiated manufacturers considering trade-in offers. The manufacturers determine their trade-in prices and maximize their profits. The equilibrium and corresponding results are then analyzed. The results show that: (1) When the products are significantly differentiated and the depreciation coefficient is moderate, the model has a unique equilibrium and market segmentation. (2) The high-quality manufacturer benefits from his own product quality standards, and his competitiveness of not participating in the trade-in market is stronger when the depreciation coefficient is large. (3) Consumers will pay more attention to the manufacturers’ product quality market positioning, because it’s important for consumers to decide whether to participate in trade-in during the second period. Therefore, enterprises should consider external factors in advance before trade-in strategies.

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    Biology
    • Construction and Application of RecET Recombination System in Zymomonas mobilis

      LI Tao, CAO-Qing-Hua, ZHANG Yi-Zheng, WU Yan, Tan Xue-Mei

      2016,53(1):209

      Abstract:

      Zymomonas mobilis is a Gram-negative bacterium with excellent ethanol-producing capabilities. The ability of ethanol yield and substrate utilization can be further improved through genetic manipulations. In this study, in order to increase the recombination efficiency of foreign genes into chromosome of Z. mobilis, the RecET genes were cloned into the E. coli-Z. mobilis shuttle expression vector pSUZM3a, resulted in pSUZM3a-RecET. The adhA gene encoding the alcohol dehydrogenase and tetracycline resistant gene were used as the target and the selection marker genes, respectively. The PCR fragments of tetracycline resistant marker with 60bp flanking sequences homologous to adhA were electroporated directly into Z. mobilis ZM4 cells which harbored pSUZM3a-RecET. After the PCR analysis and DNA sequencing, it was found that the RecET-mediated recombination reaction resulted in adhA gene replaced by tetracycline resistant gene. The result showed that RecET system could make efficient, rapid targeted gene knock-out with only 60bp homologous arm in Z. mobilis.

    • Study on the application of aquatic plants in Chengdu Egret Wetland Park

      YU Lai, CHEN Shu-Jing, LIN Wei, LUO Yan-Yun

      2016,53(1):221

      Abstract:

      Abstract: Based on field survey and analysis of data, the application status of aquatic plants in Chengdu Egret Wetland Park was studied, including the contents of species selection, planting modes, landscape effects and ecological functions, the monitoring and analysis of ambient air quality and surface water quality were also conducted. And then the advices were put forward for the further strengthening of application and growing management about aquatic plants in Chengdu Egret Wetland Park. The study provided a reference for the construction of ecological zones around the city of Chengdu in the future about the rational use of aquatic plants.

    • Screening of Phospholipase D producing Strains and its transphosphatidylation activity

      SHI Chuang, WANG Yi-Ding, MA Qin-Qin, YUAN Xiang-Hua

      2016,53(1):215

      Abstract:

      Using soybean Phospholipids as substrates,one strain which expressed Phospholipase was isolated from soil near oil mill ,the Phospholipase produce by SNUPLD-6 was identified which contain Phospholipase D . According to its mor -phological characteristics and ITS sequence , The strain SNUPLD-6 was identified as Geotrichum candidum. study on the Conditions for the growth of the bacteria and the PLD reaction conditions which expressed by SNUPLD-6. The results showed that its optimum growthtemperature is 30℃ .its optimum growth pH value is 6.0,its optimum carbon source is glucose,its optimum nitrogen source for the beef extract and peptone 50% each. the optimal fermentation time of phospholipase D producing is 3d, its optimum transphosphatidylation-temperature is 32℃. its optimum transphosphatidylation pH value is 6.0,its optimum reaction buffer for pH=5.5 0.02M HAc -NaAC buffer, its Optimal metalion activator as Ca2 +, Zn2 +.

    • Human elongation factor 1A1(eEF1A1) promotes drug tolerance in lung cancer cell line

      DING Mu-Ran, LIU Tao, LI Lin

      2016,53(1):198

      Abstract:

      Human translational elongation factor 1A (eEF1A)is a multi-functional protein besides its roles in protein translation system. The protein expressional level of eEF1A is related to cell viability in oxidative stress and apoptotic process. Based on the knowledge of multifunctional roles of eEF1A and its relation to cell viability, we studied the possible effect of the isoform eEF1A1 on the drug resistance in cancer cell lines. The eukaryotic expression vector containing eEF1A1 sequence was constructed and was transiently transfected into human lung cancer cell line H1299. After verifying the expression of FLAG -eEF1A1, MTT assay was utilized to measure the cell viability of transfected H1299 after treatment by two common anti-cancer drugs. H1299 transfected with eEF1A1 showed enhanced drug tolerance to both taxol and adriamycin. Lung cancer cell highly expressing EEF1A1 behave more tolerance to antineoplastic drugs.

    • Expression and Purification of Recombinant Chicken TSHβ, FSHβ, and LHβ Proteins

      YAN Zhen-Xin, MO Chun-Heng, WANG Ya-Jun, LI Juan

      2016,53(1):163

      Abstract:

      Gonadotropin(Follicle-stimulating hormone (FSH), Luteinizing hormone (LH))and Thyroid-stimulating hormone (TSH) are glycoprotein secreted by pituitary. Gonadotropin plays a key role in the regulation of the development and function of vertebrate gonads. TSH participates in development and metabolism by stimulate the thyroid to secrete T4 and T3. In the study, we prepared the prokaryotic expression plasmids encoding chicken TSHβ subunit, FSHβ subunit and LHβ subunit and produced the three recombinant proteins using RT-PCR and molecular approaches. We also purified the recombinant proteins by Metal Ion Affinity Chromatography. This work paves the way for future preparation of polyclonal antibodies against chicken TSHβ, FSHβ and LHβ in rabbits.

    • HPLC determination of activity of UGT75B1、UGT71B6、UGT71C5 and the kinetic analysis

      CEN Yong-Yi, LIU Zheng, LI Xu-Feng

      2016,53(1):169

      Abstract:

      The cDNA sequences of UGT75B1, UGT71B6, UGT71C5 were cloned by PCR method and then were constructed into glutathione S-transferase gene fusion vector PGEX-6P-1. All of the plasmids were transformed into E. coli strain BL21 individually for recombinant protein expression. Recombinant UGTs were purified from supernatant of cell lysates. To investigate the activity of recombinant UGTs, HPLC was employed to determine their activity to catalyze ABA and p-aminobenzoic acid. Analysis by reverse-phase HPLC was carried out using a Kromasil C18 column (250mm×4.6mm, 5μm) and glucose ester was separated by a linear gradient of 10%-100% methanol in H2O (all solutions contained 2.5ml/L of acetic acid and 0.4ml/L of triethylamine) or 10%-20% acetonitrile in H2O (all solutions contained 1ml/L of trifluoroacetic acid). The results showed that only UGT75B1 presented strong p-aminobenzoic acid acylglucosyltransferase activity and the others had lower activity. All of the recombinant UGTs had ABA-GE activity. However, UGT71B6 performed highest activity. Analysis of Michaelis-Menten kinetics of UGT75B1, UGT71B6 and UGT71C5 indicated that their Km was 0.73, 0.43 and 0.45 mM, respectively. In conclusion, our investigations demonstrate that UGT75B1 has higher p-aminobenzoic acid acylglucosyltransferase activity than ABA-GE activity. It seems that p-aminobenzoic acid is the specific substrate of UGT75B1. In comparison, UGT71B6 and UGT71C5 with similar Km perform higher ABA-GE activity.

    • Synthesis and evaluation of near infrared fluorescent dye BPAD-2 for β-amyloid plaques

      CHENG Yan, OUYANG Xiang-Shuo, LIANG Tian, ZHANG Zhi-Rong

      2016,53(1):193

      Abstract:

      OBJECTIVE We synthesized a benzopyrane derivative BPAD-2 with push-pull electronic structure, and assessed its fluorescence properties, labelling ability for beta-amyloid plaques, and blood-brain barrier penetrating ability. METHODS BPAD-2 was synthesized by condensation reaction with 1-(2-hydroxy-phenyl)-ethanone as the primary reagent, and confirmed by 1H-NMR and MS. Fluorescence spectra were observed; fluorescence staining was performed to evaluate labelling ability for beta-amyloid plaques; fluorescent imaging was performed to evaluate blood-brain barrier penetrating ability. RESULTS The emission maximum of BPAD-2 in PBS was at 658 nm; BPAD-2 showed bright red labelling of beta-amyloid plaques; BPAD-2 penetrated the blood-brain barrier and peaked at 10 min postinjection and showed reasonable washout from the brain. CONCLSION BPAD-2 showed specific labelling of beta-amyloid plaques and had good blood-brain barrier penetrating ability.

    • TAp73α-mediated cisplatin sensitivity was suppressed by miR-330 in colorectal cancer cell HCT116

      HUANG Ling, TONG Ying, XIAO Zhi-Xiong, ZHANG Yu-Jun

      2016,53(1):228

      Abstract:

      The p53 family member p73 is a transcription factor involved in the regulation of cell cycle, apoptosis and cancer cell drug-resistant. Here we reported that knockdown of p73 sensitized HCT116 colorectal cancer cells to cisplatin treatment independent of p53. Hsa-miR-330 (miR-330) was identified to be able to directly repress the expression of TAp73α. Overexpression of miR-330 decreased the protein levels of endogenous TAp73α and phenocopied the effect of p73 knockdown. Restoration of TAp73α eliminated miR-330-induced chemosensitivity toward cisplatin. Our results demonstrated a novel function of TAp73α to impair cisplatin sensitivity in colorectal cancer cells which can be repressed by miR-330, thus provided an effective strategy for therapeutic treatment of cisplatin-resistant cancer cells.

    • Extraction and physicochemical properties of Idesia polycarpa Maxim oil

      HUA Wan, YE Yang, WANG Zhan-Guo, CHEN Fang, TANG Lin

      2016,53(1):181

      Abstract:

      In this study, extraction method and decolorization as well as grease physical of the oil from the fruit of Idesia palycarpa were analyzed. The chemical compounds of the oil were separated and indentified by capillary GC-MS method. Meanwhile, the content of polyphenols from Idesia palycarpa oil were determined to provide the basis for the future development of the Idesia polycarpa Maxim. The results showed that the extraction rate by Soxhlet extraction was higher than the traditional press law, extraction rate reached 35%, while the traditional press law was 21%. Among diethyl ether, petroleum ether and n-hexane, the extraction rate by using petroleum ether with Soxhlet extraction was the highest. Through the extraction of oil, oil content of Idesia polycarpa was about 35%. Results also indicated that decolorization rate increased with the rise of the temperature, it has reached 45% while bleaching temperature up to 80℃. The main components of the oil were palmitoleic acid, palmitic acid, linoleic acid, oleic acid and stearic acid, the content of linoleic acid was the highest, up to 60%. In general, Idesia palycarpa has high oil content, and rich in linoleic acid in the oil, the results showed that Idesia palycarpa oil has considerable prospects for the development.

    • Cloning and expression regulation analysis of a JcKNOX1 gene, from Jatropha curcas L.

      SHI Xiao-Dong, TIAN Yin-Shuai, YAN Xiao-Xue, FANG Zhi-Rong, WANG Sheng-Hua, CHEN Fang

      2016,53(1):187

      Abstract:

      KNOX family genes,coding homeobox proteins,play an inmportant role in plant development.A novel homeobox gene,JcKNOX1,was cloned from the cDNA of Jatropha curcas L..The full-length ORF of JcKNOX1 was 693bp,encoding a protein of 230 amino acids residures.The predicted structure of JcKNOX1 showed that its theoretical isoelectric point and molecular weight were 6.13 and 25.92 kDa respectively.Phylogenic analysis indicated that JcKNOX1 was relation to Populus tomentosa and Citrus sinensis closely.By fluorescence quantitative PCR the expression levels were different as follows:stem apex>tender leaf>stem>leaf>flower>petiole>root,which showed that the JcKNOX1 expressed with high levels in developing organs.Meanwhile,JcKNOX was strongly induced by ABA and low temperature in Jatropha curcas L. seedlings.Through biology software prediction analysis indicated that JcKNOX1 might play an important role in light regulation,hormone regulation,expression of pollen-specific gene and abiotic stress of Jatropha curcas L..

    • The applicability of predicting protein structures with residue substitutions using homology modeling

      LIU Ji-Long, XIAO Zhi-Xiong, CAO Yang

      2017,54(3):658

      Abstract:

      Protein biological function is determined by its three-dimensional structure. Any residue substitution may lead to dramatic changes in structure and result in functional alternations. Thus it is of great importance to study the relationship between substitution and structure. Usually, proteins three-dimensional structure prediction is based on the similarity of sequence and structure. Whether this method is valid to the protein with residue substitution is still an open question. To answer this question, single residue substitution crystal structures were extracted from Protein Data Bank (PDB) to construct a non-redundant test set, which was used to assess two homology modeling structure prediction tools, SWISS-MODEL and MODELLER. The results indicate that the two methods perform well in overall structure prediction (RMSD<0.5Å), however, they fail to predict the mutants that own significant structural changes (A_RMSD>1.5Å) upon residue substitutions. The two methods perform better in mutations of embedded residues and mutations between polar residues. Although it is a small fraction of residue substitutions (<5%) that lead to significant conformation changes, they may play important roles in loss or gain protein functions. Therefore traditional homologous modeling methods are not appropriate for predicting such protein structures. There is urgent need to developing more powerful prediction methods.

    • Transcriptional expression profiles and enzyme activity of UGPase from Letinous edodes under different carbon and nitrogen sources

      CHEN Xiao-Min, WU Hai-Bing, XIANG Quan-Ju, GU Yun-Fu, ZHANG Xiao-Ping

      2018,55(1):0214

      Abstract:

      [Objectives] UDP-glucose pyrophosphorylase (UGPase) is a key enzyme involved in carbohydrate metabolism, which plays an important role in the biosynthesis of secondary metabolites. It will be helpful to elucidate the molecular mechanism of glucose metabolism to study the UGPase. [Methods] Different carbon and nitrogen sources were used to culture the Lentinula edodes Xin808 in this study. The biomasses were measured by drying the mycelium. The contents of intracellular polysaccharide were determined by phenol-sulfuric acid. The transcriptional expression profiles of ugp were analyzed by real-time quantitative PCR, and enzyme activity of UGPase were also determined. [Results] The results showed that, comparing to the control, besides NH4NO3 treatment group, the rest of carbon and nitrogen sources could increase the biomass of Letinous edodes, among which wheat bran exhibited as the best (0.63g). The small molecule (sucrose, maltose and mannose) as carbon sources and organic compounds(wheat bran and yellow bean sprouts) as nitrogen sources, ugp gene expression quantity obviously were up-regulated, increased UGPase activity, promoted the biosynthesis of mycelium intracellular polysaccharide. With sucrose as carbon source and wheat bran as nitrogen source, the transcriptional expression level of ugp gene, the activity of UGPase (4043.80U/mg and 3873U/mg) and mycelium polysaccharide content (3.60% and 3.86%) were the highest, ugp gene expression quantity respectively were 8.19 and 6.52 times to the control group. [Conclusions] The transcriptional expression levels of ugp gene, the activity of UGPase and mycelium intracellular polysaccharide of Letinous edodes showed high positive correlation between the three. The small molecule carbon sources(sucrose, maltose and mannose) and organic nitrogen sources (wheat bran and yellow bean sprouts) were helpful to the biosynthesis of mycelium polysaccharide. Sugar and wheat bran could be used as advantage carbon source and nitrogen source under Letinous edodes liquid fermentation.

    • Investigation on ubiquitination of AtCPK28 and AtCPK32 by AtTR1 in vitro

      FAN Li-Juan, CHEN Cai-Li, ZHU Xu-Hui, HUANG Kui, YAO Run-Dong, WANG Jian-Mei

      2017,54(3):617

      Abstract:

      AtTR1, AtCPK28, and AtCPK32 are functioning in the abiotic stress response in Arabidopsis thialiana, and closely associated with the calcium signaling pathway. In order to analyze relationships between AtTR1, AtCPK28 and AtCPK32, we expressed AtTR1, AtCPK28, and AtCPK32 in Escherichia coli, purified expression proteins, and studied the ubiquitination of AtCPK28 and AtCPK32 by AtTR1 in vitro. The results showed that the AtCPK28 and AtCPK32 were multi-ubiquitylated by AtTR1 in vitro. It indicated that the AtCPK28 and AtCPK32 are potential downstream targets of AtTR1 in the regulation of stress resistance signaling pathways. These findings provided experimental evidence to further study the interactions between AtTR1, AtCPK28, and AtCPK32, and also provided some insights of their molecular mechanisms in the plant under abiotic stresses.

    • Targeting EGFR-L858R mutation by Cpf1 and Cas9 nuclease

      WEI Heng, YANG Mei-Jia, ZHONG Kun-Hong, Quan Ai-Ping

      2018,55(2):401

      Abstract:

      Mutations in the EGFR kinase are a cause of non-small-cell lung cancer. Deletions in exon 19 and the L858R (2573T>G) single point mutation constitute about 90% of all EGFR mutations. Selectively inactivate only mutant, not normal allele, could benefit patients with such mutations. Here, the editing efficacy and selectivity of CRISPR-Cpf1 and -Cas9 systems on EGFR L858R mutant allele were analyzed by dual-reporter assay in vitro. Near the mutation site, there are two TTTN protospacer adjacent motifs (PAMs) for Cpf1. 2573T>G substitution also leads to occurrence of a novel NGG PAM for Cas9. Thus we designed two AsCpf1 gRNA (gRNA1 and gRNA2) and one SpCas9 gRNA (gRNA3) and evaluated their potency and allele specificity in vitro using a dual fluorescent protein-based bioassay system. As a result, both AsCpf1 and SpCas9 demonstrated robust activities to induce specific editing of only 2573T>G mutant EGFR, not wild-type sequence. Our results support the potential applicability of both Cpf1 and Cas9 in precision medicine through highly specific disruption of mutant oncogenes.

    • Functional analysis of Arabidopsis thaliana BAH1 in

      LIANG Ke, XU Xi-Bing, NIU Yu-Long, YANG Yi

      2017,54(3):623

      Abstract:

      Protein ubiquitination is one classic type of post-translational modification. The ubiquitin ligase E3 could interact directly with the substrate and mediate in large part the ubiquitination specificity. Arabidopsis thaliana BAH1 encodes a ubiquitin E3 ligase with a C3HC4-RING finger domain, which could bind two zinc ions to form a cross brace zinc finger. Here, we found the zinc finger structure of BAH1 and DnaJ was similar. Further self-ubiquitination assay in vitro demonstrated BAH1 possessed E3 ligase activity. We also found BAH1 can confer heat tolerance of E. coli as DnaJ by temperature-sensitive assays. Hence, these results indicated that BAH1 may improve heat tolerance of E. coli through interacting with DnaK/DnaJ chaperone system.

    • The molecular structure of Phytoene desaturase and the analysis of the interaction between PDS and norflurazon

      HUANG Guo-Zhou, LI Yuan-Yuan, DENG Peng-Chen, BAI Lin-Han

      2017,54(4):874

      Abstract:

      Phytoene desaturase(PDS) is the target of the bleaching herbicide,norflurazon.The the 2D and 3D structures of wild PDS and two mutations were achived by online prediction,docking of PDS and norflurazon was carried out by DOCK6.5.Binding stablity was analysed by molecular dynamics simulation via the software Gromacs.The energy changes and distribution were revealed by mm_pbsa.pl tools in Amber9.At last,important amino acids were confirmed by the analysis of hydrogen bond with LIGPLOT+. The results suggested that different mutations didn’t change the 2D and 3D structures of PDS,but mutated PDS showed higher RMSD,which indicated lower binding stablity,and higher bingding energy,which indicated the difficulity to bind to noflurazon .Our research might explain the mechanisms of the resistance to norflurazon.

    • Effect of three dietary supplementations of probiotic bacteria on egg quality of Lehmann Pink layers

      LONG Ai-Lin, LIU Lun, LIU Jia, DU Zheng-Da, YANG Li-Qin, DENG Jie, WANG Yan, YIN Hua-Dong, ZHU Qing, LI Tian-Jie, ZHAO Xiao-Ling

      2016,53(6):1375

      Abstract:

      This experiment was conducted to investigate the impact of probiotics (Bacillus subtitles, Lactobacillus plantarum and Pediococcus pentosaceus) on egg quality of Caoke chicken. Four hundred and eighty new-born chicks of Lohmann Pink layers were randomly divided into 4 groups with 3 replicats. The control group was fed the basic diet (CP). And the experimental groups were added Bacillus subtitles (BS), Lactobacillus plantarum (LP), and Pediococcus pentosaceus (PP), respectively. The average amount of bacteria was no less than 107 CFU per day. The eggs quality (n = 600, at 220 d) differences among the experimental groups were shown as following: compared with the control group, the yolk color of group LP deepened by 2.91% (P<0.05), and group PP deepened by 1.68% (P<0.05), respectively. The average yolk weight of BS was heavier than the control group by 4.09% (P<0.05), and its average shell thickness was thicker than the control group by 9.64% (P<0.05), and the egg weight of BS was higher than the control group by 3.22 % (P<0.05). All analysis showed that egg quality traits were significantly affected by the three probiotics. Bacilli subtilize (BS) performed better than Lactobacillus plantarum (LP), and Lactobacillus plantarum (LP) performed better than Pediococcus pentosaceus (PP). This study provided the basic information for putting the three probiotic into egg production in chickens.

    • Complete sequence and comparative analysis of the chloroplast genome of the Chinese aspen (Populus adenopoda, Salicaceae)

      FAN Li-Qiang, HU Huan, ZHENG Hong-Lei, WANG Tian-Jing, WANG Ya-Ling, MA Tao, MAO Kang-Shan

      2018,55(1):0165

      Abstract:

      Although Populus (Saliaceae) is an important group of forest trees in the sense of economy, ecology and scientific researches, few is known about the structural and sequence variation of chloroplast genome across the genus. We sequenced and characterized the complete chloroplast genome of the Chinese aspen (Populus adenopoda), and made comparative analyses of the structure variation of the chloroplast genomes of P. adenopoda and other 11 poplars. The P. adenopoda chloroplast genome is 158,591bp in length, exhibits a typical quadripartite structural organization, consisting of a LSC region of 84,634 bp, two IR regions of 27,667 bp and a SSC region of 18,623 bp. Comparison of the cp genome structure and gene order to those of the 12 Populus species indicated that the chloroplast genomes of this genus are rather conservative, only six large deletions or insertions were found across the whole genome. Phylogenetic analysis demonstrated that the 12 Populus species clustered into three well-supported clades, and Chinese aspen is most closely related to the white poplar, P. alba. Our work will better our understating of the evolutionary history of Populus, and will be useful to future population genetics and other molecular ecology studies of poplars based on chloroplast DNA sequences.

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    Electronics and Information Science
    • Time Variation Characteristics and Assessment of Electromagnetic Environment in a Campus

      ZHANG Ming-An, ZHAO Xiang, XU Jin-Hai, YAN Li-Ping, HUANG Ka-Ma

      2016,53(1):93

      Abstract:

      With the increasing complexity of the electromagnetic environment (EME), it is necessary to perform actual measurement and evaluation of the EME. Because of the temporal dynamic and random variation of the EME, time variation characteristics of the EME in a campus are considered in this paper. By choosing sampling points in different regions of the campus, respectively measuring electric field value of the sampling points during different time periods, and using statistical analysis of the measurement data, we get the figures of probability density distribution and time variation curve of the electric field. And then, the time variation characteristics of the actual EME are analyzed and discussed, the distributions of the EME in different regions are compared, as well as a brief evaluation of the electromagnetic radiation level in the campus is given.

    • Quantum authentication and key agreement scheme for SIP protocol

      YANG Guang, NIE Min, YANG Wu-Jun

      2016,53(1):87

      Abstract:

      To overcome the shortcomings of current SIP safety scheme, such as the incapability to detect the wiretap and the vulnerability of the classical key system in case of quantum computation attack, this paper proposed a novel user authentication and key agreement scheme that combined quantum safe communication methods and SIP protocol. The SIP server prepared the three particle W states and distributed two of them to the SIP users. The random inserted particles were measured first to detect the wiretap; then the rest of the W states were operated and measured to authenticate the user. After that, every particle of the W states was measured randomly and the two SIP users got the initial conversation key according to the results of the effective measurements. The performance analysis shows our scheme is capable of resisting the impersonation attack and wiretap attack, thus can increase the safety of SIP protocol effectually.

    • A novel error resilience scheme for key frames in Wyner-Ziv video coding

      LIU Xiao-Juan, QING Lin-Bo, XIONG Shu-Hua, OU Xian-Feng

      2016,53(1):98

      Abstract:

      In Wyner-Ziv video coding system, correct transimission and accurate decoding of key frames would affect the whole system performance directly. However, in wireless communication system, data loss of key frames often happened due to network failure, network congestion or other reasons. Data lossy seriously affect the decoding quality. This paper presents a novel solution for the data loss of key frames under the conditions of feedback channel. In the solution, by sending some extra Wyner-Ziv code streams along with the origin key frames, errors of the damaged image at the decoder can be high-efficiently corrected and restored. Simulation results show that the proposed solution could reconstruct the damaged image effectively, and the quality could be improved up to 20dB compared with typical error concealment method when the data loss ratio is 1%~20%. Furthermore, R-D performance of key frames could be improved even if the data loss ratio is very high.

    • Obstacle avoidance for mobile robots strategy based on laser radar

      XIANG Ya-Jun, YAN Hua

      2017,54(3):529

      Abstract:

      Laser radar has the advantages of high scanning precision,so it is used to obtain the information about the environment around the robot.In order to solve the problems about trough width calculation and pure steering in the VFH algorithm,a method to calculate the trough width and check the traversability of the robot in this trough is proposed.Based on the acquiring goal orientation, local target points are added as the result of the VFH algorithm.In addition,a control strategy of smooth turning is designed,which makes the robot to approach the target position with smooth way in a complex environment.Finally,effectiveness of the method is verified by experiments.

    • Using homogenous dielectric superstrate to enhance the bandwidth of a microstrip antenna

      ZHENG Zhi, CHEN Xing, XU Guang-Hui, WANG Hao, HUANG Ka-Ma

      2016,53(2):326

      Abstract:

      A superstrate is able to significantly increase the gain of an antenna, and this superstrate based technology has been widely used. However, the studies about the effects of superstrates on the return loss of the antenna are limited. In this work, taking homogenous dielectric superstrates and a probe-fed microstrip antenna as examples, using numerical simulations, the effect of superstrates on the return loss of an antenna is investigated. The simulation results show, by proper design of some structural parameters, such as the distance between the superstrate and the antenna, the feeding location of the antenna and so on, the dielectric superstrate can improve both the gain and the impedance bandwidth. A prototype is fabricated and measured, and the measured results shows that it has a gain of 14.5 dBi and a |S11|<-10dB impedance bandwidth of 11.19% , which verifies the simulations.

    • A method for road extraction from high resolution color remote sensing image

      XIE Ming-Hong, SONG Na

      2017,54(1):81

      Abstract:

      In this paper, a road extracton method is proposed by combining kernel-based Fisher linear discriminant (FLD) classification and shape feature. This method has four main steps: First, the color information of labeled samples is extracted. Then kernel-based Fisher linear discriminant is used to implement feature classification to segment the images into two categories: road and non-road, according to the information extracted before. After that, the road shape optimization features are used to remove erroneous extraction. Finally, morphological processing are used to optimize the extraction results.Experiment results show that the proposed method in this paper can realize the extraction of road from remote sensing image with color information.

    • Community discovery in weighted social networks based on similarities of common neighbors

      LIU Miao-Miao, GUO Jing-Feng, MA Xiao-Yang, CHEN Jing

      2018,55(1):0089

      Abstract:

      In order to divide communities accurately in weighted networks, a hierarchical clustering method IEM based on the similarity and modularity is proposed. Firstly, the similarity of the two nodes is defined based on attributes of their common neighbors. Then, the most closely related nodes are clustered fastly according to their similarity to form the initial community and expand it. Lastly, these communities are merged with the goal of maxmizing the modularity so as to optimize division re sults. The algorithm achieves more reasonable and effective community division for weighted network by three steps of initializing, expanding and merging communities. Correctness and effectiveness of the algorithm are verified through experiments on many weighted networks using weighted modularity as evaluation index. Results show that IEM is superior to weighted CN, weighted AA and weighted RA. Moreover, it can achieve the higher quality of community division in weighted networks compared with CRMA algorithm.

    • Measurement and Correlation Analysis of Electromagnetic Environment in a Campus

      XU Jin-Hai, ZHAO Xiang, ZHANG Ming-An, YAN Li-Ping, ZHOU Hai-Jing

      2016,53(2):347

      Abstract:

      In this paper, the electromagnetic environment (EME) in a campus is measured and then analyzed adopting statistical method. The results establish the spatial distribution of the EME in this campus, and the characteristics of EME in different areas are compared. The probability density functions (PDF) of the measured data are calculated and depicted, and some other valuable results are also obtained. These measured data and statistical results provide necessary support for evaluating and analyzing the EME. And these data could be utilized to affirm theoretical analysis method of EME. Finally, this paper presents a method that using Correlation to represent the complexity of EME. Two electromagnetic field intensity probes are used to sample the electric field strength of different positions simultaneously, the Correlation Coefficients between two electric field strength versus two different time series are calculated to measure the complexity of EME, and the figures of correlation coefficient corresponding to each component and total field versus distances are presented.

    • A New Method of Synthesizing Tinnitus Rehabilitation Sound Based on IFS Algorithm and Broken Chord

      XU Yuan-Yuan, HE Pei-Yu, CHEN Jie-Mei

      2017,54(3):517

      Abstract:

      Tinnitus is a sensation of sound without external stimulation and it is common on clinical .Tinnitus retraining therapy (TRT) is a recognized treatment of relieving tinnitus. Scientific researches show that some similar and unrepeatable music can be used as the sound of TRT .This paper proposed a new method of generating fractal tones based on IFS and broken chord .Applying this new method in the synthesizing could make all the notes within the scale and appeared randomly .Furthermore, the adjustability of neighboring notes avoided the tone mutation. By using this method, the tinnitus rehabilitation sound achieved a balance of predictability and randomness .Experimental results showed that it had obvious fractal characteristics and remained the fractal image features. By adding broken chords, the music turned into more coherent and mildly pleasant songs .So it had reference significance to the treatment of tinnitus.

    • Characterization of the Pore Morphology of 3D Rock Models Using Spherical Harmonic Functions

      HAN Xue, TENG QI-Zhi, QING Lin-Bo, WU Xiao-Hong

      2017,54(3):509

      Abstract:

      Aiming at the statistical characteristic function and conventional spherical harmonic functions could not effectively describe 3D rock models, rock spherical harmonic functions were proposed. This algorithm was an improvement on the conventional spherical harmonic functions used in 3D model retrieval. Firstly, the 3D rock model was decomposed into a series of concentric spheres. On each sphere, a spherical function was obtained. By restricting the spheres to different radii, a collection of spherical functions could be obtained. Then, spherical harmonic transform was used on these functions to get morphological characteristics descriptor. Finally, a similarity comparison function was used to measure the similarity between each 3D rock models .Experiments on multi-group sandstone core samples show that the proposed algorithm is efficient in describing 3D rock models, and that the depicting ability of the new algorithm is exacter than the statistical characteristic function and the conventional spherical harmonic functions.

    • Analysis of Informatizationed Application of Medical Management Based on Block Chain Technology

      HE Bo, WANG Gui-Sheng

      2018,55(6):1219

      Abstract:

      Medical management informationization is an important means to improve the health level of the whole people under the special national conditions of China’s large population and scarce medical resources. This paper discusses a series of problems in medical management informationization development in China and points out the importance of blockchain based application in medical management information system. Blockchain technology can be used to tackle some issues such as interconnection, confidentiality, non tampering and sharing in medical information resources, which will provide important technical support for the further development of Internet+medical care in China.

    • A fast 3D reconstruction algorithm of multiple point statistics

      ZUO Chen, TENG Qi-Zhi, HE Xiao-Hai, GAO Ming-Liang

      2016,53(2):337

      Abstract:

      Based on the SNESIM algorithm, a fast three-dimensional(3D) reconstruction algorithm of multiple-point statistics simulation was proposed. First, pattern sets were built by the red-black tree. The height of tree structures was rapidly reduced. CPU time for retrieving matching data events was saved. Then, the algorithm combined the advantages of probability aggregation approach and the sequential two-dimensional(2D) simulations with sample data approach. Half-template and all-template were utilized in nodal simulation. The proportion of informed conditioning nodes in template was increased so that the amount of possible data event was declined. The algorithm was tested on 2D channelized reservoir section, 3D porous medium images and 3D reservoir rock images. The results showed that this algorithm achieved the efficiency without degradation of accuracy. No matter isotropic or anisotropic rocks, the visual characteristics, the statistics characteristics and the pores-throats structures of the reconstructions were similar to the corresponding real 3D digital rock images, which proved that this algorithm was reliability.

    • Joint Angle, Range and Velocity Estimation for bi-static FDA-MIMO Radar

      ZHAO Zhi-Hao, WANG Zhi-Min, SUN Yang

      2017,54(6):1202

      Abstract:

      It is known that there is a contradiction between range estimation and velocity estimation due to the influence of pulse repetition frequency (PRF) in traditional phased-array (PA) radar. In this paper, a joint unambiguous angle, range and velocity estimation method is proposed for bi-static multiple-input-multiple-output (MIMO) radar with frequency diverse array (FDA). Owing to the FDA, there is a little frequency increment between the arrays and the transmit steering matrix carries angle, range even velocity information. Consider the range-angle coupling in transmit steering matrix, a subarray-based transmitted waveform and decoupling approach are designed. Utilizing the ESPRIT algorithm and ambiguity resolve methods based on FDA, the direction-of-departure (DOD), direction-of-arrival (DOA), range and velocity parameters are estimated unambiguously. Additionally, Cramér-Rao bounds (CRB) for these parameters are derived and the performance of this radar is analyzed. Simulation results indicates the validity of the proposed method.

    • Stochastic resonance of impurities diffusion induced by dichotomous noise and square-wave signal in a semiconductor layer

      OU Jian

      2016,53(2):331

      Abstract:

      The stochastic resonance (SR) in a semiconductor layer driven by a dichotomous noise and square-wave signal is investigated. On the assumption that the system satisfies the adiabatic approximation condition, applying the two-state theory, the expression for the output signal-to -noise ratio (SNR) of the system is obtained. The non-monotonic influence of the surrounding temperature on the SNR is found. It is shown that the SNR is a non-monotonic function of the standard deviation of the impurities’ position and the system bias: By choosing the deviation and bias of the impurity, the system SNR can be tuned. For low temperature, large bias can improve the system SNR. Moreover, the SNR increases with the amplitude of the square-wave signal and the ratio between temperature of the hot and cold reservoirs for relatively high temperature, while the SNR decrease with the increase of potential energy and the strength of the dichotomous noise. The results obtained in this paper have certain theoretical significance for the semiconductor design and the investigation of the semiconductor layer process.

    • The Research of Drain Induced Barrier Lower Effect for SOI Strained Silicon Schottky Source/Drain MOSFET with High-k Gate Dielectric

      XU Li-Jun, ZHANG He-Ming, YANG Jin-Yong

      2017,54(4):753

      Abstract:

      The SOI strained silicon schottky source/drain MOSFET with high-k gate dielectric is a potential device realizing small size MOSFET, which combines the advantages of strained silicon engineering, high-k gate dielectric, SOI structure and schottky source/drain. A model for the structure is proposed by solving two dimensional Possion’s equation, which takes into account for the impact on the source/drain schottky barrier height for electron of image force barrier and size quantization effect, then the drain induced barrier lower model is investigated based on the threshold voltage model. The experiment data of drain induced barrier lower extracted from literature is compared with the model, which verifies its correctness, and discuss the variety relationship between drain induced barrier lower and several parameters. The result shows that drain induced barrier lower increases with strained silicon thickness, channel doping and germanium fraction increasing, decreases with channel length, gate dielectric constant, intrinsic schottky barrier height for electron and drain source voltage increasing. The device can suppress drain induced barrier lower effect greatly through adjusting the model parameters properly, which can provide some reference for the design of SOI strained silicon schottky source/drain MOSFET with high-k gate dielectric device and circuit.

    • Efficiency Improvement of Magnetic Resonant Wireless Power Transfer System Based on Ferrite Reflector

      LI Yong-Feng, GUO Qing-Gong

      2017,54(4):742

      Abstract:

      A ferrite reflector-based optimization design of magnetic resonant wireless power transfer (WPT) system to improve transmission efficiency is proposed. The WPT system composed of four resonators is considered as a two-port network to deduce the transfer efficiency. Then a magnetic resonant WPT system whose receiving and transmitting coils have a diameter of 30cm is designed and manufactured. The measured transmission efficiency is above 90% at the distance of 30cm while decreases to about 40% when the distance increases to 60cm. Measured results are in good agreements with simulated ones. Based on this WPT system, two different ferrite reflectors are introduced to improve the transmission efficiency. Results show that the different size of magnetic reflectors may have positive or negative effects on transmission efficiency. By optimizing the ferrite reflector, the maximum 15% improvement of transmission efficiency is obtained at the distance range of 30cm to 90cm.

    • Gray level DAG maximum entropy based on quantization resolution for Medical image tone enhancement

      SONG Lu, FENG Yan-Ping, WEI Ya-Bo

      2018,55(2):316

      Abstract:

      In order to improve the medical image sharpness and contrast, and improve the computational efficiency, we proposed the gray level DAG maximum entropy based on quantization resolution for Medical image tone enhancement. Firstly, we used a simple piecewise autoregressive (Piecewise autoregressive PAR) image target model for recovery, and taked into account the error of analog to digital conversion to use least squares algorithm to estimate PAR model parameter, which obtain high resolution image histogram restoration model; Secondly, aiming at the problem of low contrast may exist, the least squares algorithm for constrained optimization problems was modeled in DAG, which constructed a hue preserving constraint optimization model of maximum entropy image enhancement, and the characteristics of the DAG figure Monge theorem was used to reduce the computational complexity; Through the above two steps, the image details and contrast enhancement in the process of medical image enhancement are realized. The simulation results show that the proposed algorithm can provide more effective medical image enhancement effect.

    • Operational characteristic and approximation performance analysis of Oustaloup fractance circuits

      LIU Pan-Pan, YUAN Xiao, TAO Lei, YI Zhou

      2016,53(2):353

      Abstract:

      In this paper, we investigated operational characteristics and approximation performance of Oustaloup fractance rational approximation from a new perspective of fractional calculus operation. Based on order-frequency characteristic and phase-frequency characteristic theoretical analysis, we start from the operational characteristics of pole-zero sub-systems, by the pole-zero recursive distribution of which, we study operational characteristics of Oustaloup fractance, and in order to analyze its operational characteristics and approximation results, relative error function,approximation bandwidth, K-index, complexity and approximation effect were used. Theoretical results showed that fractional order-frequency characteristics can analyse Oustaloup fractance rational approximation simply and exactly, the fractance rational approximation has faster approximation speed and lower complexity. Providing a solid foundation for the application of Oustaloup fractance circuit, to provide a theoretical basis for the design of fractional controller.

    • Hyperspectral image classification of multi-layer local perceptual convolutional neural networks

      ChiTao, WangYang, ChenMing

      2020,57(1):103

      Abstract:

      To solve the problems on high nonlinearity in spectral features in hyperspectral image classification, a classification algorithm, based on multi layer perceptron convolutional layer and batch normalization layer improved convolutional neural network in spectral domain processing, is proposed to improve the nonlinear feature extraction ability. By constructing a seven layer network structure, the algorithm implements a multi layer local sensing structure, analyzes the spectral information pixel by pixel, distinguishes the spectral information of different targets, takes the full spectrum segment set as input, discards the spatial information, and uses the momentum gradient descent training. The algorithm trains multi layer local perceptual convolutional neural networks to realize the extraction and classification of spectral features of different target objects. In the experiment, two sets of hyperspectral remote sensing images are used for comparative analysis. Taking the Pavia University data set as an example, in the case of 3 600 training samples, the test set is 1 800 samples, the accuracy of the proposed method is 9023% and the accuracy of the LeNet 5 and Linear SVM method are 8794% and 9000% respectively. In the case of 21 000 training samples, the test set is all samples, the accuracy is 9723%, 9664% and 9240% respectively for the proposed method, LeNet 5 and Linear SVM method. The experimental results show that the proposed method is superior to the traditional neural network in the case of small training set, which can effectively extract the data features, and is superior to SVM algorithm for the small sample classification in terms of accuracy and computational cost. In the large scale training set, this method shows good learning ability and is superior to LeNet 5 in classification accuracy. The multi layer local perceptual network structure proposed in this paper enhances the learning ability of nonlinear features, it can utilize hyperspectral images much more effectively than traditional SVM and general deep learning networks, both in small sample classification and large sample classification. The spectral domain information of the pixel by pixel point can effectively improve the classification accuracy.

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    Physics
    • Preparation and luminescent of Zn1-xMnxS nanoparticles

      WANG Qing, ZHANG Xu-Dong, WEI Zhi-Qiang, DAI Jian-Feng, LI Wei-Xue

      2016,53(1):152

      Abstract:

      Mn-doped ZnS (ZnS:Mn) nanoparticles were prepared via hydrothermal method, studied effects on photoluminescence that different proportions Mn ions on Zn1-xMnxS. The composition, morphology, microstructure and optical property of the sample were characterized by X-ray diffraction (XRD).The results showed that the Zn1-xMnxS (x = 0,0.01,0.03,0.05,0.07,0.10) nanoparticles were spherical hexagonal structure of nanocrystalline, uniform particle size between 15 ~ 20nm. At room temperature, using the UV excitation wavelength is 350nm stimulate Zn1-xMnxS nanoparticles. Blue light emission which is produced by transition between shallow donor level and manganese t2 level can be obtained. Luminous intensity with the increasing amount of manganese-doped increased decreased after the first.And emission peaks have a mobile with the change of manganese-doped content. The reason may be related to sulfur vacancies which influence shallow donor level of ZnS. The proportion of zinc-manganese has an impact on the amount of sulfur vacancies and level position.

    • Effect of many-body interactions on the equation of state for Solid Argon

      LI Ji-Hong, ZHENG Xing-Rong, PENG Chang-Ning

      2016,53(1):131

      Abstract:

      By using ab initio self-consistent field Hartree-Fork methods and atomic clusters expanding theory and employing Gamess program, two- and three-body interaction energies and the equation of state for solid argon in fcc crystal have been quantificationally calculated at the neighboring atomic distance R=2.40 -4.00 Å under high pressure. In addition, the convergence and truncation of atomic energy multi-body expansion are analyzed. It is found that two-body contribution to the cohesive energy is positive, while the three-body contribution is negative in solid argon under high pressure. At high pressure, only the consideration of the two-body contribution will overestimate the cohesive energy, hence it is necessary to introduce the three-body negative effects. The phenomenon of the experiment under 80GPa can be explained by considering the three-body potential.

    • The comparison of several time phase unwrapping methods

      zhaowenjing, chen wen jing, su xian yu

      2016,53(1):110

      Abstract:

      Abstract: One of the key steps in 3D optical shape measurement based on the structured light projection is the phase unwrapping. The unwrapping issue about the complicated phase map is also the difficult step of the methods. The temporal phase unwrapping provide a useful tool to obtain the continuous phase map from the complicated wrapped phase map. Along the time direction, the temporal phase unwrapping is independently carried out from a 3D distribution demodulated from grating fringes with different pitches projected on the tested object. Therefore the problem of the error propagation in 2D phase unwrapping algorithm can be avoided. Followed by the comparison among the typical temporal phase unwrapping methods, including the negative exponential method, three pitches unwrapping method, three pitches heterodyne unwrapping method and its improved technique, a segmentation curve fitting method is used to improves the phase calculation accuracy. The computer simulations and experiments are carried out to verify that the phase error is deduced greatly through the segmentation curve fitting.

    • Electronic and magnetic properties of Fe-doped ZnO nanowires

      TONG Qiao-Ying, LI Sha-Sha, CHEN Hong-Xia

      2018,55(5):1031

      Abstract:

      The electronic and magnetic properties of ZnO nanowires doped with one and two Fe atoms are comparatively studied in terms of the first-principles calculation. The formation energies of doped nanowires are smaller than those of the pristine ones, indicating that the doping process is an exothermic reaction. The result shows that Fe atom prefers to the surface position. The magnetic moments are mainly contributed by the Fe-3d orbital. Due to the hybridization interaction, a small magnetic moment is also induced in nearest neighboring O atoms. The magnetic moments of the Fe and O atoms have the same direction, indicating ferromagnetic coupling between them. Surface doped nanowire is semiconductor, while middle doped nanowire is half-metalic, which have important applications in spintronics.

    • Nuclear coupling parameters affect hyperon phase in the neutron star

      MU Xue-Ling, JIA Huan-Yu, HONG Bin, ZHOU Xia

      2016,53(1):118

      Abstract:

      Hyperon emergence and the proportion of hyperon have significant influence on the properties of the neutron star, How the different nuclear interaction models affect the neutron star is an important physical problems. In terms of the relativistic mean field theory, selecting different nucleon coupling parameters of neutron stars to calculate the density of hyperons. And we will find that the different nucleon coupling parameters have different extent influence in hyperon emergence and the transition of neutron star to hyperon star. The interaction potential of sigma meson and omega meson potential have a significant influence, but the influence of rho meson potential is small. These results have important reference value in researching the massive neutron star.

    • Pathology of the Fermionic Representation of Transverse Ising Model

      GUO Xiao-Ting, LI Peng

      2016,53(1):124

      Abstract:

      When studying the quantum Ising chain in a transverse field, we usually transform the spin operators to fermion operators by applying the Jordan-Wigner transformation,i.e.we take it for granted that the spin model and corresponding fermionic model are equivalent naively. But deliberate treatment could reveal that the equivalence accompanies some delicate conditions.Redundant degrees of freedom should be projected out carefully, especially for finite length of chain. In this paper, we compare the two models in detail so as to find the conditions of equivalence of them,including the interaction, the boundary conditions, and odevity of the number of lattice sites.We also exemplify in detail how to project out the redundant degrees of freedom for the fermionic representation.

    • First principles studies on mechanical properties of ZrB3 and NbB3 under high pressure

      AO Te-Gen, YING Chun, ZHAO Er-Jun, HOU Qing-Yu

      2017,54(3):547

      Abstract:

      The mechanical properties and the electronic structures of transition metal compounds ZrB3 and NbB3 (m-AlB2, OsB3 and MoB3 structures) under high-pressure are studied by using the first-principles within density functional theory. It was found that m-AlB2 is the most stable structure under normal pressure. The pressure-induced phase transition occurs at the pressure of 40 Gpa, OsB3 structure becomes the most stable one under high pressure. m-AlB2-NbB3 has a maximum shear modulus of 204 GPa, the highest Debye temperature of 921 K, and the highest hardness of 27.3 GPa. The harnesses are estimated to be 24.9 GPa, 22.6 GPa and 19.8 GPa for MoB3-NbB3, OsB3-NbB3 and m-AlB2-ZrB3, respectively. The calculated density of states (DOS) illustrated that the electronic structures of considered compounds are governed by the strong hybridization between M-4d and B-2p states. All compounds are metallic.

    • Simulation of the vector beams generated by the polarization modulation of the spatial variant wave-plate

      SHI Cheng-Fang, JING Jian-Li, GuoMinglei

      2017,54(3):541

      Abstract:

      In order to study the generation of the vector beams by using the polarization modulation of the spatial variant wave-plate, the Jones vectors and Jones matrix are used to further discuss the process, in which an arbitrary Laguerre-Gaussian beam can be transformed into vector beam. Based on the mathematical mode, the far-field intensity distributions of the generated vector beams have been simulated by numerical method. The simulated results show that, the line-polarized and circularly polarized beams with basic mode can be converted to vector beams by using spatial variant half-wavelength plate and quarter wavelength plate respectively, and the dark core of the output beam increases with an increase of the order of the spatial variant wave-plate. The effects of the spatial variant wave-plate on the helical beams can be equivalent to the superposition of two mutually orthogonal circularly polarized helical beams. The polarization test of the orbital angular momentum confirms the practicability of this method.

    • An Analytical Drain Current Model for Surrounding-Gate Schottky Barrier MOSFET

      XU Li-Jun, ZHANG He-Ming, YANG Jin-Yong

      2017,54(3):553

      Abstract:

      The current of Schottky barrier metal-oxide-semiconductor field-effect transistor (MOSFET) is popularly calculated through the integration of Fermi-Dirac distribution for carrier over energy or self consistent iterative numerical calculation. In order to reduce the calculation complexity, this paper presents a new analytical drain current model for surrounding-gate Schottky barrier MOSFET through adopting several fitting parameters which takes into account for the impact on the Schottky barrier height of image force barrier lowering effect, dipole barrier lowering effect and quantum effect at smaller size. The proposed drain current model is in good agreement with the reported experimental data in the literature, which verifies the correctness of the model and can provide some reference for the design of surrounding-gate Schottky barrier MOSFET device and circuit.

    • Theoretical research on structural stability and electronic structure of XeF2 under high pressure

      WANG Hai-Yan, YANG Bing-Fang, WANG Biao, SHI Rui-Li

      2017,54(4):781

      Abstract:

      The structural properties of XeF2 in the pressure range from 0 to 80 GPa are studied by plane-wave pseudopotential density functional theory method. The calculated values are in agreement with the experimental data. Based on the calculated elastic constants of XeF2 under different pressures, the I4/mmm structure of XeF2 is confirmed to be stable in the pressure range from 0 to 80 GPa. The band gap of XeF2 at different pressure is calculated and the band gap is found to decrease with the increase of pressure. When the pressure is greater than 10 GPa the band gap of XeF2 increases linearly with the increase of pressure, which indicates that XeF2 transforms from the insulator to semiconductor and has more and more strong metallic with the increase of pressure.

    • External field effect on the molecular characteristics and potential energy of SiH

      WU Dong-Lan, WU Ai-Jin, WEN Yu-Feng, ZENG Xue-Feng, XIE An-Dong

      2017,54(3):579

      Abstract:

      By setting different electric fields and adopting density functional B3P86/cc-PV5Z method, the geometric structure of SiH molecule is optimized, and the bond lengths, dipole moments, vibration frequencies and other physical properties parameters are obtained. On the basis of adopting the energy of high precision coupled cluster CCSD (T) method and the same basis set to scan single point energies, the potential energy curves of different external fields are given. The results show that the physical properties parameters and potential energy values will change with the changes of external electric fields, especially, of the reverse direction electric field. In order to get the critical dissociation electric parameter, the dipole approximation is adopted to construct potential model, then the model is put to fit the corresponding potential energy curve of external electric field. It is found that the fitted critical dissociation electric parameter is reasonably consistent with the numerical calculation; i.e., the relative errors are also less than 4%. So the model constructed is reliable and accurate. These will provide some theoretical and experimental reference for the studies of molecular spectroscopy, dynamics and molecular cooling with Stark effect.

    • Constitutive model for dynamic mechanical response of high strength steel

      XIE Hong, YU Jian-Chao, WANG Gang, RONG Yi-Ming, YE Jin-Wen, LIU Ying

      2016,53(2):382

      Abstract:

      It’s important to understand the deformation behavior of metals in the dynamic loading process. In this study, the dynamic mechanical responses of high strength steel are investigated by uniaxial compressive experiments on the Split Hopkinson Pressure Bar (SHPB) with strain rate range from 3000 to 12000s-1 and temperature range from 20℃to 800℃. The experimental results show that the mechanical responses of steel investigated are strongly affected by the strain, strain rate and deformation temperature. The flow stress increases with the increasing of strain rate while decreases with the increasing of deformation temperature. A phenomenological constitutive model is established to describe the strain rate harden and temperature soften behavior. The stress-strain relationships predicted by the phenomenological constitutive model agree well with the experimental results, which shows that the proposed constitutive model can be used to study the dynamic deformation process furthermore.

    • Elastic and electronic properties of CuAlSe2 under pressure: A first-principle study

      ZHOU Meng, LU Zhi-Peng, TAO Ying-Qi, HUANG Ao, ZHOU Le, ZHOU Xiao-Yun, HU Cui-E

      2017,54(4):771

      Abstract:

      We employ the first-principles plane wave method in the frame of density functional theory (DFT) to investigate the equilibrium lattice structure, the mechanic, thermodynamic and electronic properties of CuAlSe2 compound. The lattice constants, the bulk modulus B0 and its pressure derivative B0’ are calculated. Based on the quasi-harmonic Debye model, we also obtain thermal expansion coefficient. It is noteworthy that the variation tendencies of these parameters are investigated detailed with pressure. In addition, we also calculate the elastic constants of CuAlSe2 compound. Results show that the elastic constants C11、C33、C12 and C13 increase with increasing pressure, whereas the influences of pressure on elastic constant C44 and C66 are not obvious. The calculated elastic constants satisfy the hecriterion of mechanical until the pressure grows to more than 15GPa, which suggests the structure phase transition of CuAlSe2 may be happened. We also investigate the shear sound velocity VS, longitudinal sound velocity VL, and Debye temperature ΘE from our elastic constants, as well as the thermodynamic properties from quasi-harmonic Debye model. We obtain the dependence between the heat capacity Cv and pressure, and the same as thermal expansion coefficient α. At last, the pressure dependences of band structures and density of states are also investigated, which shows that the value of TDOS decreases with the increase of the pressure.

    • Neural signals transformation of magnetite-based magnetoreceptor

      QIAN Xia

      2018,55(2):323

      Abstract:

      Magnetoreceptor existing in the living beings is the mechanism supporting the biological magnetic navigation, and the process of magnetic information transforming to neural signals is the key process of magnetoreceptor mechanism, however it is still hypothesis. In this paper, the process of magnetic information transforming to nerve signals of the mechanism of electromagnetic induction, magnetic protein biocompass and magnetite-based magnetoreceptor are characterized, and then a possible way to cognize the process of magnetic information transforming to nerve signals from the point of view of theory is presented .

    • High-order harmonic generation from He+ driven by the chirped pulse combined with the unipolar pulse

      LIU Hang, LI Yi, YAO Zhen, FENG Li-Qiang

      2018,55(1):0118

      Abstract:

      The generations of the high-order harmonic and the attosecond pulse from He+ ion driven by the chirped pulse combined with the unipolar pulse have been numerically investigated. The results show that by preparing the initial state as the coherent superposition of the ground and the first excited states of He+ ion, the harmonic yield is enhanced by 6 orders of magnitude in comparison with the single ground initial state case. Further, by introducing the laser chirp and the unipolar controlling pulse, the cutoff energy of harmonic spectrum is remarkably enhanced, and the interference structure of harmonic is also reduced. Further, with the introduction of the spatial inhomogeneous effect, the harmonic cutoff can be further extended, resulting in a super-bandwidth of 320 eV. By superposition of harmonics, three attosecond X-ray pulses with durations from 45 as to 48 as can be obtained, which is 5 ~ 6 orders of magnitude improvement in comparison with the single ground initial state case.

    • Three Dimensional Reconstruction Based on Improved Empirical Mode Decomposition

      LI Xu-Qin, CHEN Wen-Jing, SU Xian-Yu

      2018,55(1):0111

      Abstract:

      Aiming at the problem of the edge error caused by the traditional empirical mode decomposition method, an improved empirical mode decomposition method is proposed for eliminating the decomposition error in the edge zones of the signals in this paper, in which, a mirror extension method and Gerchberg extrapolation iteration is introduced to eliminate the decomposition error at edges position, respectively. The improved method can effectively suppress the mode decomposition error caused by the signal edge and improve the decomposition accuracy of the EMD. It is also applied in the analysis of the deformed fringe pattern for eliminating the background components in 3D optical measurement, by which a better reconstructed result of 3D surface can be obtained.

    • Theoretical studies on the Electronic structures and oxygen carrying functions of TPPFe(II) and L-Thr-TPPFe(II)

      JIANG Jun-Hao, ZHOU Hui, JIANG Qi-Hua, DENG Ping

      2016,53(2):367

      Abstract:

      The geometry of TPPFe(II) and L-Thr-TPPFe(II) were optimized using density functional theory (DFT) at the B3LYP level with the mixed basis sets: Lan2dz for Fe(II), 6-31G(d) for C and H atoms, and 6-311++G(2d, p) for N and O atoms. To simulate real conditions, the solvent effects of CHCl3 and H2O were studied using the polarized continuum model (PCM). The electron density at the bond critical point was calculated using the topology analysis of the Multiwfn software. Based on the calculated data of electrostatic potential obtained by quantitative analysis of molecular surface using the Multiwfn software, the molecular electrostatic potential maps were illustrated using VMD software. The bond length and electron density at the bond critical point indicate the coordination bond between the Fe(II) atom and the O atom of carbonyl group in L-threonine and the intramolecular hydrogen bond between H(7) atom and N(1) atom. The porphin ring is warped by the effect of the coordination bond and the intramolecular hydrogen bond. The coordination effect between the Fe(II) atom and carbonyl group may weaken the bond strength between Fe(II) atom and O2, but it is beneficial for the reversible oxygen carrying functions. The solvent effects of CHCl3 and H2O may attenuate the intramolecular hydrogen bond and the coordination effect between the Fe(II) atom and carbonyl group, and enhance the warping of porphin ring and the coordination effect between Fe(II) atom and O2. The computation of molecular electrostatic potential show that the more negative value outside the O atom, N atom and benzene ring are contributed by lone-pair electrons and π-electrons, respectively. The electrostatic potential outside the H atom of the benzene ring and the Fe(II) atom is positive. The most positive value is outside the Fe(II) atom which is the most probable active sites in coordination reactions between the Fe(II) atom and O2.

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    Mathematics
    • Positive solutions of third-order ∞-point boundary value problems

      GAO Ting, HAN Xiao-Ling

      2016,53(1):35

      Abstract:

      In this paper, we study the existence of positive solutions to the third-order ∞-point boundary value problem u'''+ λa(t)f(u) = 0, t ∈ (0,1),u(0) = βu'(0), u(1) =∑αiu(ξi), u'(1) = 0,where λ > 0 is a parameter, ξi∈ (0,1), αi∈ [0,+∞], and satisfy ∑αi>1,0<∑αiξi(2−ξi) < 1. a(t) ∈ C([0,1],[0,∞)), f ∈ C([0,∞),[0,∞)).By using Krasnoselskii’s fixed point theorem in cones, we can obtain the existence of the positive solution and the eigenvalue intervals on which there exists a positive solution if f is either superlinear or sublinear.

    • A BP-LSTM trend forecast model for stock index

      SUN Cun-Hao, HU Bing, ZOU Yu-Xuan

      2020,57(1):27

      Abstract:

      In this paper, according to the time series characteristics of financial data, such as stock index, stock price, etc, we introduce the Artificial Neural Network (ANN) and Recurrent Neural Network (RNN) in deep learning to stock index prediction and build a BP-LSTM model based on the Back Propagation (BP) neural network model and Long Short-Term Memory (LSTM) neural network model. Numerical analysis shows that the accuracy of our model is higher than that of the traditional machine learning models, and it also has some improvement compared with the ordinary LSTM model.

    • Global optimality conditions for mixed integer nonlinear programming problems

      QUAN Jing, LI Guo-Quan

      2017,54(3):452

      Abstract:

      In recent years, the application of mixed integer nonlinear programming problem has been extremely active and very extensive. In this paper, some necessary conditions for a given global minimizer applied to mixed integer nonlinear programming problem with bounded constraints which arises in continuous as well as discrete optimization have been developed. Also, some sufficient global optimality conditions for mixed integer nonlinear programming problem with bounded constraints are established. The global optimality conditions readily apply to problems whose objective functions are generally twice continuously differentiable. If the objective functions are quadratic, then the global optimality conditions become verifiable. Some simple numerical examples can illustrate the significance of the optimality conditions.

    • A model fro recommendation of applicable law articles based on transfer learning

      YANG Chao-Qun, PANG Yan-Yan, YAN Ruo-Bing, ZHANG Shi-Quan, HU Bing, WANG Zhu

      2021,58(2):021001

      Abstract:

      In this paper, we propose a model for the recommendation of applicable law articles. As an application, the judgment documents data sets of fraud and divorce dispute are selected from the criminal and civil cases. Based on transfer learning, the legal word vectors are trained from the pre-trained general word vectors by using the FastText model. Then, the text is classified according to the well trained vectors. The simulation results show that for both the fraud and the divorce dispute, after the transfer learning, the applicable law can be recommended comprehensively and accurately for the case discription text, especially for the targeted regulations and judicial interpretations. With the continuous improvement of the transfer learning mode, our model is expected to be further applied to the evidence pushing and sentencing prediction.

    • The complexity of the dual bases for Gauss normal bases of type (n,k)(k\geq 3) over finite fields

      LIAO Qun-Ying, LI Xue-Lian

      2016,53(2):235

      Abstract:

      It is well known that normal bases over finite fields have been implemented efficiently in software. The hardware and time complexity of multiplication using normal bases depends on the structure of the normal basis used, particularly on the complexity of the normal basis. Therefore to determine the complexity for normal bases, especially Gauss normal bases over finite fields, is interesting. By properties for finite fields and elementary techniques, we obtain the upper and lower bounds of the complexity for the dual basis of a class of the type (n,k)(k\geq 3) Gauss normal bases, and determine the explicit complexity of the dual basis for the type (n,k)(k=1,2) Gauss normal bases over finite fields, which is an elementary proof for the main results given by Wan and Zhou in 2007.

    • Sensor Selection for Hypothesis Testing in Wireless Sensor Networks

      QIAN Bo, MA Ting, SONG En-Bin

      2018,55(1):0007

      Abstract:

      The well-known sensor selection issue is of great significance in wireless sensor network. We aim at selecting a subset of out of sensors to conduct the corresponding hypothesis test based on their observations such that the false alarm rate attains the minimum, which has been proved to be NP hard. In this paper, we relax the original problem to a tractable one and propose a new algorithm, which can achieve the KKT point. Moreover, compared with the existing algorithm, our algorithm is more efficient since it has lower computation complexity. Simulations also illustrate that the global optimum can be reached in most cases.

    • Multistable analysis for one dimensional Hopfield neural networks

      SU Juan, HE Zhi-Rong

      2016,53(2):260

      Abstract:

      This paper focuses on multistable analysis of one dimensional Hopfield neural networks, whose sigmoid activation function may not be bounded. Firstly, the condition for the existence of equilibria is established. Moreover, the conditions for exactly 1, 2, or 3 equilibria and their stability respectively are proposed with some constraints for network parameters. Then, the corresponding results about the equilibria features are supplemented in the remaining cases for the parameters. Thus, we obtain the relationships between all the different values of the parameters and the number of equilibria as well as their stability. Finally, by employing bounded and unbounded activation functions, two examples and numerical simulations are used to illustrate the theory developed in this paper.

    • Characterization of Optimal Feedback for SLQ with General Filtration

      REN Yan

      2018,55(1):0042

      Abstract:

      One of the fundamental issues in Control Theory is to design feedback controls. Which is well achieved in the case of linear quadratic control problems. To date, the study of this problem in the stochastic setting is focused much on the natural filtration. In this paper, we utilize the notion of transposition solution to give a sufficient condition for the existence of an optimal feedback control for the stochastic linear quadratic control problems with random coefficients in the general filtration setting, and show it is also necessary for 1-dimensional system.

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    Computer Science
    • Topology analysis of Chinese airspace domestic flights

      WU Ke, WANG Jun-Feng, LUO Qin

      2016,53(1):73

      Abstract:

      The research of ad-hoc network based on Chinese airspace flight topology will help to meet the needs of future flights on aspects of air traffic control and information sharing,but the existing studies has not analysis the flights topology according to the specific condition of Chinese airspace. This paper collects real Chinese airspace domestic flights data and divides the Chinese airspace into east part,west part, and flight information region with NS2 simulation,and compares Chinese airspace flight topology within one day and 24 hours. The results showed that the distributions of Chinese domestic flights have big differences with each other in the Chinese airspace,however,the number of the flights shows a relative high linear correlation with the population and the third output.

    • The Research of network traffic identification based on Convolutional neural network

      LI Qin, SHI Wei, SUN Jie-Ping, DONG Chao, QU Tian-Shu

      2017,54(5):959

      Abstract:

      In recent years, the deep packet inspection technology and traffic identification technology based on the statistical characteristics of data packet have developed rapidly. But they have some disadvantages. The deep packet inspection technology can’t identify the encrypted network traffic, and the other technology heavily relies on subjectively chosen statistical features. A network traffic identification method based on convolutional neural network algorithm is proposed in this paper. According to certain rules, the network data is converted to gray images. In order to improve the recognition rate, the original network data is extended according to the order of the TCP packets and the disorder of the UDP packets. Experimental data shows that this method has a high detection rate both in the application and application layer protocol.

    • Research of Internal Image Move-Copy Tampering Forensics Algorithm

      LI Ruo-Chen, JU Shen-Gen, ZHOU Gang, SHAO Shou-Ping

      2016,53(1):67

      Abstract:

      According to the low robustness characteristics of image tampering with evidence of general move-copy algorithm, this paper proposes a new algorithm. Firstly, it uses the color invariant feature to detect feature points, which improves recall forensic results. Secondly, it uses the RGB color channel to expansion Surf descriptor, which increases the robustness of feature vectors. Then, it defines noise sensitivity coefficients to identify and deal with the image noise points and use sequential similarity detection algorithm to improve feature points registration. Finally, it uses Kendall coefficient and the four hypothesis to constrain the forensic results and get the final result. Experimental results show that the new algorithm reflects higher accuracy and strong robustness and it has strong ability of forensics.

    • Image enhancement new model based on rational-order Partial Differential

      jiangwei, 李小龙, 刘亚威

      2016,53(1):47

      Abstract:

      In order to sharpen the image edge features while enhancing texture detail, the image enhancement model based on space rational-order derivative was constructed by the effective combination of integer-order theory and fractional-order calculus theory to derive the differential expression of rational-order partial differential, and the numerical of enhanced model was achieved using rational-order partial differential mask operator. The experimental results showed that compared with the fractional-order differential method , the image enhancement model can be obtained the effect of continuous variation, that not only enhanced image texture well, but also improved the edge enhancement effect. Objectively, using image edge evaluation parameters of texture features such as information entropy and average gradient for quantitative analysis and experimental verification shown that the new model combined the advantages of integer and fractional order differential to make up for their lack of own and achieved a good image enhancement results.

    • Automatically generating visually pleasing Information Walls

      CHEN Rui, XIE Ying-Tao, HUA Li-Xian, CHEN Yu, LIN Tao

      2016,53(1):61

      Abstract:

      Information Wall (IW) is a GUI composed of rectangular cells each contains various kinds of information. The design and implementation of IW are mainly in a manual way nowadays, which typically leads to less variability in appearance style and low efficiency. This paper develops a tool to automate the generation of text-IWs based on a genetic programming algorithm. A model, which evaluates the visual quality of text-IWs, is also proposed and incorporated in the algorithm to make generated IWs more visually pleasing. Test results show that the tool is able to efficiently produce good looking IWs with variable appearance styles. With the help of the tool, designer productivity could be improved by utilizing machine-generated prototypes.

    • Research on Encryption of Digital Image Based on Improper Fractional-order Laser Chaos

      ZHAO Jian-Feng, WANG Shu-Ying, Li Xian-Feng, Zhang Li-Tao

      2016,53(1):79

      Abstract:

      To improve the safety of information encryption, based on an improper fractional-order laser chaos, a digital image encryption algorithm is proposed. The key space is formed by initial state variables, parameters and orders of the system. Every pixel value is included in secret key, so as to improve anti-attack capability of the algorithm. Lena gray image and Couple color image are encrypted in numerical simulation. Theoretical analysis and simulation results show that this algorithm with a sufficiently large key space not only can perfectly resist the ciphertext attack and differential attack, but also is excellent against chosen plaintext attack and statistical attack, which can be used in secure communication of multimedia data.

    • Radar target tracking algorithm based on adaptive DBSCAN

      ZHANG Qiao, YANG Hong-Yu, LIU Hong, LIU Yu, YAN Zhen

      2021,58(1):012001

      Abstract:

      Directly processing the track initiation and tracking of the points recorded in the radar point recorder of the three dimensional air traffic control system will generate a large number of false alarms and a large amount of calculation. When performing target tracking, the number of candidate point sets is huge is the main reason for the large amount of calculation in the target tracking process. Based on the dynamic adaptive DBSCAN clustering algorithm and the classic Kalman filter tracking algorithm, a hybrid dynamic adaptive DBSCAN clustering tracking algorithm is proposed in this paper to reduce the number of candidate point sets. Experiments have found that the number of invalid points is reduced and the track quality is improved Computing time decreases. Through the dynamic adaptive DBSCAN clustering tracking hybrid algorithm, it can quickly track the target detected by cnac radar once and form the target track, which can detect the black flight target in time and reduce the interference to the normal flight of civil aviation aircraft to the minimum.

    • Research of Stock Time Series Based on probabilistic Suffix Tree

      CHENG Xiao-Lin, ZHENG Xing, LI Xu-Wei

      2018,55(1):0061

      Abstract:

      this paper introduces a Probabilistic Suffix Tree (PST) method based on the time series symbolization, and constructs a stock forecasting model based on the combination of time series symbolizationa and PST. In addition, the Markov Model MM and the Auto Regressive Moving Average Model (ARMA) are compared with the forecasting model of this paper.The stock of 10 CSI 300 indices is used as the experimental sample. The results show that the stock forecasting model proposed in this paper is better than the MM model and the ARMA model,and proves the validity of the forecasting model proposed in this paper.

    • Basic elements of brain-like computing: From memristor to fracmemristor

      PU Yi-Fei, YU Bo, YUAN Xiao

      2020,57(1):49

      Abstract:

      In this paper, fractional-order memristor (fracmemristor), a novel basic element of brain-like computing, is discussed.The concept of memristor is extended from the conventional integer order to the fractional order, i.e. the fracmemristor. Fracmemristor is a compound word of fractional-order memristor, whose fractional impedance is fracmemristance. Accordingly, it is natural to think of a range of theoretical challenges: What is the relationship of fracmemristor to the conventional fractor and the famous memristor? What are the interpolation properties between the memristor and the capacitor or inductor? Where is the location of fracmemristor in the Chua's circuit periodic table? What are the general expressions for fracmemristances of arbitrary-order ideal capacitive and inductive fracmemristors? What are the measuring unit and physical dimensionality of fracmemristor? What are the fingerprint features for identifying fracmemristor? How to implement arbitrary fractional-order memristor effectively in the form of analog circuit with ordinary memristor, capacitor and inductor? This paper makes preliminary discussions on the above challenging theoretical problems based on abundant prior exploratory findings. The fracmemristor solves the problem that fractor is difficult to realize the function of memory charge or magnetic flux. As a basic circuit element, the fracmemristor can be applied to the design of chaotic system, neural circuit and neural network circuit.

    • Personalized NewsRecommendation Technology Based on Improved Collaborative Filtering Algorithm

      HUANG Xian-Ying, XIONG Li-Yuan, LI Qin-Dong

      2018,55(1):0049

      Abstract:

      The traditional collaborative filtering algorithm only based on matrix produced by user access history to make recommendation and sparse data,and also cannot reflect the user’s interests timely, contrary to these problems, the personalized recommendation technology news in the traditional collaborative filtering algorithm proposes the calculation of news text content similarity and the concept of the time window , the calculation of news content similarity also takes into account the part of speech and positions of the feature words in the news, the time window is used to create user interest model which will change over time; The experimental results show that the improved algorithm effectively improves the sparse problem of data which user has accessed and captures user interest timely, F-measure value improves the maximum 10% compared to the traditional algorithm, the highest value of mean absoulte error fell by 7%, greatly improving the quality of recommendation.

    • Comprehensive evaluation model of users' satisfaction based on gray relational analysis and AHP

      CHEN Wei-Peng, LIU Xu-Hao, TANG Ning-Jiu, LIN Tao, LIU Wen-Jing, PENG Jian

      2017,54(4):713

      Abstract:

      For the issue of less effective usability comprehensive evaluation on users' comments with uncertain information and complex evaluation indexes, a users' satisfaction comprehensive evaluation model is applied on usability research of production, which integrates gray relational analysis and AHP (Analytic Hierarchy Process). In order to enhance the objective of gray relational analysis, AHP method is used to determine the relative weights of evaluation index so as to establish comprehensive evaluation model of users' satisfaction model. With contrast experiment on the dataset of smart mobiles in different price, the satisfaction rank from our model is very similar to the one of actual sales. In addition, experiment result shows gray relational analysis can distinguish the satisfaction difference of productions more clearly. So above experiment results illuminate our model can comprehensively effectively evaluate users' satisfaction of production with incomplete assessment information

    • Research on reconstruction algorithm of boiler combustion temperature field based on AT

      WU Yu-Hui, YANG Lan-Fei, ZHAO Li, ZHOU Xin-Zhi

      2021,58(6):062002

      Abstract:

      In order to monitor the combustion state and measure the temperature distribution in the furnace, a three layer progressive grid temperature field reconstruction algorithm based on acoustic tomography (AT) is proposed. The algorithm first computes the sparse grid temperature information with the least squares method (LSM), and then uses the least squares support vector machine (LSSVM) to establish a fine grid model for the temperature field. In order to further improve the reconstruction accuracy, the parameters of the LSSVM reconstruction model are tuned by the differential evolution algorithm (DE) (Referred to as the LLD algorithm) to establish a detailed temperature description of the entire measured temperature field. Through the reconstruction of three different types of temperature fields provided by Dongfang Boiler Industry Group, the results and error analysis show that the LLD algorithm can describe the temperature distribution information of the measured combustion zone globally and achieve high-precision reconstruction of the temperature field.

    • Multi-target Tracking Data Association Algorithm Based on Greedy Strategy

      ZHANG Liang, WANG Yun-Feng

      2018,55(1):0056

      Abstract:

      Abstract:In this paper,a new association method is proposed to tackle the data association problem of multi-target tracking.In this algorithm, building the associative matrix with the Euclidean distance and the 1-Norm of state vector between tracks and points firstly.And using the associative matrix find the most suitable(Maximum matching success rate)points for every track. If the points just marked by one track, update this track directly; if the points marked by many tracks, choose the track with highest probability to update. Monte-Carlo Simulation experiments show that this algorithm guarantees the updating points for every tracks are the best points among all present points.

    • Heuristic Anomaly Detection Model of Industrial Control System Based on Combined Neural Network

      TANG Zhang-Guo, LI Huan-Zhou, zhang jian

      2017,54(4):735

      Abstract:

      In order to improve the intrusion detection rate of industrial control system, the principle of traditional industrial intrusion detection technology is discussed, and the comparative study is done from the viewpoint of information theory. The dynamic and static fingerprints of industrial control attacks in the protocol stack, statistical characteristics, and communication behavior are summarized based on the modeling of the specificity of the industrial control system and the attack methods. Based on a new abstract method of heterogeneous information, a heuristic industrial control system anomaly detection model based on combinatorial neural network is implemented. The test results show that the proposed model is more efficient, and the results are more accurate than the conventional intelligent methods.

    • An Adaptation Social Spider Optimization Algorithm Based on Dynamic Multi-swarm Strategy

      LIU Zhou-Zhou, LI Bin

      2017,54(4):721

      Abstract:

      In order to improve the samples diversity and convergence properties of social spiders optimization algorithm (SSO), an adaptation social spider optimization algorithm based on dynamic multi-swarm strategy (DMASSO) is proposed. According to the algorithm samples diversity and evolutionary level, the spider population is dynamically divided into different sizes leading groups and supporting groups, and the adaptive learning factor and Gaussian disturbance factor are introduced to improve the algorithm update ways, which helps to improve the algorithm global optimization ability and maintain the diversity of the sample population. For the test results of typical characteristics functions show that compared to SSO algorithm, SFLA algorithm and other optimization algorithms, the new algorithm has better convergence speed and convergence accuracy.

    • Optimization of multi joint robot motion of hydraulic drilling vehicle based on ant colony algorithm

      WEI Peng, LUO Hong-Bo, ZHAO Kang, LONG Wei

      2018,55(6):1171

      Abstract:

      Hydraulic rock drilling rig plays an important role in modern tunneling construction. The existing hydraulic drilling rig is completed by the operator when locating the hole position. The order of locating holes and the time to search holes is not optimized, which results in time waste and low efficiency. In view of the above problems, in this paper, the multi node motion and the time of locating hole path of long arm multi joint intelligent rock drill are optimized for large tunnel section and complex hole system. The innovative research is as follows: by the rock drilling tunnel form and excavation mode analysis, as well as the explosion hole parameters setting, a collision free planning is proposed for the left and right manipulator drilling tasks. At the same time, the total change time of each joint variable of the multi joint manipulator is used as the optimization objective function. The ant colony algorithm is used to optimize the objective function, and the optimized hole finding path with the shortest hole positioning time is obtained, which improves the positioning and finding efficiency of the hydraulic rock drilling rig mechanical arm.

    • Research on DDoS detection based on BP neural network

      YANG Ke-Xin, SANG Yong-Sheng

      2017,54(1):71

      Abstract:

      Distributed denial of service attack (DDoS) is a common threat in today’s networks. While such an attack is not difficult to launch, defending a network resource against it is disproportionately difficult. This paper analysis some famous theories and methods on detection of DDoS network attacks systematically based on the fast neural network algorithm. Meanwhile, the attack traffic feature model which is constructed based on the packet length, packet transmission time interval and packet length change rate etc is proposed. Second, a method to optimize the parameters of the neural network error is also proposed by a large number of attempts. Finally, the UCLA dataset is used to carry out the contrast experiment of the parameters before and after the improvement. Experiments show that the proposed method can effectively detect DDoS attacks and has a better generalization ability.

    • genetic-immune algorithm based on receding horizon for aircraft landing scheduling problems

      CHEN Wen-Ping, LIANG Wen-Kuai, LI Yi

      2016,53(2):311

      Abstract:

      Flight scheduling has been a complex and key task for the air traffic control (ATC), and aircraft landing scheduling (ALS) problem is one of the core issues. ALS is a NP-hard problem with a large scale and multi-constraints characteristics. Thus, in order to solve the flight landing problem effectively and rationally, a flight landing scheduling algorithm based on receding horizon and genetic-immune algorithm (RHC_HGIA) is proposed. RHC_HGIA solves the problem of flight landing by two aspects mainly, one is that selecting the flights that are waiting to land and need to be optimized based on the receding horizon length and size which have been set; on the other hand, optimizing The selected flights which are waiting to land by using genetic-immune algorithm and determining actual landing time of them. the flights that have been optimized form a new flight landing sequence, selecting the flights from the sequence that the actual landing time of them in the field within a given time range to land. Then resetting receding horizon length and re-selecting the flights to be optimized until all pending landings have landed so far. In this paper, simulation is conducted in the airport control simulation system on the base of an airport of 20 flights to be landing of one day. Simulation results show that, RHC_HGIA algorithm can solve ALS problem preferably, and comparing with traditional flights landing scheduling algorithm(FCFS), the extra costs of flight is reduced much more.

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    Chemistry
    • Synthesis and Characterization of Micro- and Nano- Metal-porphyrin Coordination Polymer

      YANG Jian-Dong, HUANG Shan

      2016,53(1):145

      Abstract:

      Micro- and nano-scale metal-organic complexs not only have size effect, but have an adjustable assembly unit, which shows a lot of good performance. in this paper, we synthesized nanoscale mertal-porphyrin complexs by a simple and green method. by choosing the different metal ions, the different nanostructures (0D, 1D, 2D) of metal-porphyrin polymer was abtained by controlled assemble unit. its structures were characterizatized by scanning electron microscopy (SEM), infrared spectroscopy (IR), x-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and were detailed examinated of the impact and dynamica growth of the metal-porphyrin polymer.

    • Structure and Spectral Properties of HgmSen(m=1,2,3,n=1,2) Molecular and Molecular Ion lusters

      SHANG Long-Chen, LIU Xin-Ping, LI Jiao, NI Shu-Ping, LIAO Hong-Hua

      2016,53(1):138

      Abstract:

      This paper adopted the LANL2DZ pseudopotential basis set and B3LYP method to calculate the microstructure and electronic properties of HgmSen(m=1,2,3,n=1,2) molecules and molecular ion clusters. Meanwhile, it utilized the time-dependent density functional theory to calculate the absorption spectra, thus obtaining the ground state structure, electronic properties, binding energy, energy gap, dipole moments and other microscopic properties. Then it analyzed the frontier molecular orbital characteristics, identified all the harmonic vibration mode and absorption spectroscopic properties. The results show that: when m+n=1~3, the linear and angular types are the stable geometry with ground state; when m + n = 4 ~ 5, the ring type is the stable geometry with ground state, besides, compared with other molecular clusters, HgSe2 molecular cluster have the greatest stability, binding energy and the minimal energy gap. HgmSen(m=1,2,3,n=1,2) molecules and molecular ion clusters have better electron donors, receptors and other active sites, that is, great electrical conductivity. The maximum absorption wavelength λmax of each cluster with different composition lacks of regularity, but for the molecular clusters with the same composition and its corresponding positive and negative ions, there appears significant red shift or blue shift. The results could provide theoretical reference for the further experimental and applied research, and it is conducive to studying the nature of experiments as well as certain laws of massive condensed matter.

    • Motion pattern of the complex involved in klebsiella pneumoniae carbapenemases and β-Lactamase inhibitor protein

      ZUO Ke, DU Wen-Yi, DAI Tian-Yang, LIU Wei, LIANG Li, hujianping

      2017,54(3):585

      Abstract:

      Carbapenems, used in clinical treatment of multi-drug resistance bacterial infection, can be hydrolyzed by Klebsiella pneumoniae carbapenemases, which weaken the treatment effect of gram negative bacterial infection. It’s an important means of improving the clinical efficiency of these antibiotics to develop novel, potent and specific Klebsiella pneumoniae carbapenemase inhibitors. And β-lactamase inhibitor protein can competitively inhibits Klebsiella pneumoniae carbapenemases. The movement patterns of complex involved in Klebsiella pneumoniae carbapenemase and β-lactamase inhibitor protein are analyzed by coarse-grained models. The results indicate the movement patterns of Klebsiella pneumoniae carbapenemase change a lot after it is inhibited by β-lactamase inhibitor protein. Finally, the binding modes between the series of cyclic boronic acid β-lactamase inhibitors and Klebsiella pneumoniae carbapenemase are released by molecular docking and molecular dynamics simulation, and explained the relationship between the recognition mechanism and conformation-inhibition activity of these inhibitors from the angle of hydrogen bonds and energy. This research provides a theoretical basis of the subsequent design of the inhibitor based on the Klebsiella pneumoniae carbapenemase structure.

    • Optimization experiment study on Zinc oxide ore leaching zinc

      HUANG Ping, LI Lai-Cai, ZHANG Yuan

      2017,54(3):595

      Abstract:

      Abstract:Using Response Surface Methodology(RSM), selecting Quadratic model, on the basis of model Box-Behnken experiment design optimization in NH3-(NH4)2SO4-H2O system leaching of zinc oxide ore experiment process parameters, and the regression equation is established.Regression analysis model of "Prob>F" value of 0.0023, less than 0.05, the model of high precision, all between independent variable and dependent variable of the regression equation is significant, regression equation to be trusted. Model analysis found that the liquid-solid ratio, leaching temperature, leaching time, the three factors that affect the leaching rate of zinc is significant, the analysis of the response surface and contour plot, liquid-solid ratio and the leaching time of interaction is significant.RSM analysis ,the optimum leaching conditions were obtained as follows: liquid-solid ratio 12.81, leaching temperature 30 ℃, leaching time of 4.15 h, total ammonia concentration of 7.5 mol•L-1, predicting leaching rate was 86.2%.Considering the feasibility of the operation, in the NH3-(NH4)2SO4-H2O system leaching process of zinc oxide ore, selected liquid-solid ratio 13, leaching time 4h, leaching temperature 30 ℃, total ammonia concentration of 7.5 mol•L-1, measured the leaching rate was 86.0%, compared with the theoretical prediction error is 0.23%.

    • On the interaction of 1,4,7-Triazacyclononan -Co(Ⅱ)with Bovine Serum Albumin

      QI Juan, WANG Wen-Wen, LIU Fan

      2016,53(2):397

      Abstract:

      The interaction of 1,4,7-Triazacyclononan -Co(Ⅱ) (Cyclen-Co(Ⅱ))with bovine serum albumin (BSA) has been investigated by fluorescence method. The results show that the Cyclen-Co(Ⅱ) strongly quenched fluorescence of BSA. It was proved that the fluorescence quenching mechanism belonged to the static quenching by Stern-Volmer equation. According to Lineweaver-Burk equation and thermodynamics equation, the binding constants,binding sates and thermodynamics parameters were obtained at different temperatures in the aqueous solution and in the solutions of Brij35、CTAB、SDS. The hydrophobic interaction forces played a main role in the binding of Cyclen-Co(Ⅱ) with BSA.

    • Study on the adsorption of rare earth metal cerium ions (IV) by pectin

      ZHANG Li-Yuan, CHEN Qi, Liu Yi-wu, ZHOU Da-Li

      2017,54(4):807

      Abstract:

      The adsorption of rare earth metal cerium ions by low fat pectin was determined. The effects of the adsorption time, pH of the cerium ion solution, adsorption temperature, dosage of pectin and concentration of cerium ions on the adsorption capacity of pectin were investigated. The adsorption process was analyzed by the Langmuir and Freundlich models. Using the adsorption isotherm, the related thermodynamic and kinetic parameters were calculated, and infrared spectrum analysis was performed. The results indicate that the variables studied significantly affect the adsorption of cerium ions by pectin and that the infrared spectra before and after adsorption are apparently different, implying that a chemical reaction may have occurred in the adsorption process. The Freundlich equation is better suited to describe the adsorption process compared to the Langmuir equation. The adsorption process is best described by a pseudo-first order kinetics equation. Enthalpy and entropy differences are the driving forces of the adsorption process.

    • Density functional study of styrene

      HE Wei-Ping, HUANG Ju, WANG De-Tang, LIU Xiao-Jing

      2016,53(6):1322

      Abstract:

      The molecule of styrene was investigated with the density functional theory (DFT), and the molecular geometries was optimized by using B3LYP method at different levels of basic sets. Based on the optimized geometries, the molecular orbitals, the energy levels, the highest occupied orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), the infrared absorption spectrum (IR) and Raman scattering spectrum (Raman), the nuclear magnetic resonance (NMR), and the ultraviolet-visible absorption spectroscopy (UV-Vis) have been obtained with the density functional theory (DFT). According to the calculation results of the molecular orbitals and energy levels, the attributes of the highest occupied orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were mainly discussed. The simulated results of the infrared absorption spectrum (IR) and Raman scattering spectrum (Raman), the nuclear magnetic resonance (NMR), and the ultraviolet-visible absorption spectroscopy (UV-Vis) were compared with the experimental data, and the spectral data were concisely analyzed and discussed.

    • Study on Aqueous Two-phase Extraction of Salidroside

      GUO Qing-Feng, WANG Feng-Wei, CHEN Dong-Hui, WANG Dao-Wu

      2016,53(2):403

      Abstract:

      Based on aqueous two-phase system of polyethylene glycol (PEG)/salt, a simple pretreatment approach was developed for the extraction and determination of salidroside in Rhodiola. The influence factors on phase behavior of forming biphasic and partition behavior of the ATPS was investigated. Studied the factors such as polyethylene glycol (PEG) molecular weight and the mass fraction, the kinds of salt, the salt mass fraction, ionic strength, salidroside initial concentration influence on salidroside extraction rate. Determine the optimum extraction conditions with orthogonal experiment, when the aqueous two-phase system is 20%PEG1000, 20% (NH4)2SO4 and 1% KCl, the extracting effect is best; the extracting rate is 95.32%.Compared with the conventional liquid–liquid extraction or solid-phase extraction, this method was more environmentally, more cost effective.

    • Nonlinear dielectric behavior study of chemical reactions in a strong electric field

      HONG Tao, TANG Zheng-Ming, ZHU Hua-Cheng, LAN Jun-QIng, HUANG Ka-Ma

      2017,54(1):131

      Abstract:

      In the presence of a strong electric field, novel phenomena always happen in chemical reactions, including the change of chemical reaction rate and the shifting of chemical equilibria. However, the mechanism is still unknown. This paper studies the interactions between chemical reaction systems and strong steady electric fields. Based on the theory of molecule reorientation, the modified Smoluchowski equation is expanded by the Legendre polynomials. The general expression of polarization is derived by considering the second-order nonlinear response. The nonlinear variation is also discussed through a simple isomerization reaction. The result shows that the ratio between the second-order nonlinear term and the polarization is proportional to the electric field. Meanwhile, the condition for which the result applies is also discussed.

    • Studies on Spectra and Thermodynamic Properties of Dual Prenylated Flavonoids

      Qi Wen-Sheng, Wang Hai-Feng, Li Quan

      2016,53(2):389

      Abstract:

      The molecular structures, spectral and thermodynamic properties of Dual Prenylated Flavonoids were calculated using the Density Functional Theory B3LYP method. Then, the polarized continuum models(PCM) of Tomasi were used to discuss solvent effects. The computational results showed that the lowest energy absorption wave length were 325.6 and 361.9 nm for 1R and 2 molecules in gas, and the solvents and polarity have few influence on the lowest energy absorption wave length. At 298 K and standard pressure, the thermodynamic properties ΔfHm of 1R and 2 molecules were 3455.51 and 3691.26 kJ/mol, respectively, and thermodynamic properties ΔfGm of 1R and 2 molecules were 4028.23 and 4282.98 kJ/mol, respectively, and Sm of 1R and 2 molecules were 834.90 and 834.97 J.mol-1.K-1, respectively.

    • Dynamic adsorption and elution performances of H2TiO3-lithium adsorbent loaded on ceramic foams

      ZHANG Li-Yuan, LIU Yi-Wu, ZHOU Da-Li, YAO Qian-Qian

      2017,54(6):1275

      Abstract:

      H2TiO3-lithium adsorbent was loaded on cordierite-based ceramic foams by the sol-gel process. The adsorption and elution of Li+ by the obtained samples were studied with the ion exchange columns via the dynamic process. The effects of liquid flow speed, Li+ concentration and single column/multi columns on the adsorption capacity and enrichment factor of Li+ were studied. The results indicate that it needs a long time for the lithium adsorbent loaded on ceramic foams to reach the leakage, and the adsorbent has a high operational adsorption capacity. In a certain range, flow rate of the eluent does not affect enrichment factor of Li+ apparently. The adsorbent does not have the ability to enrich Li+ with a high concentration. However, it is capable for the adsorbent to enrich a low level of Li+. The enrichment factor of Li+ can at least reach 26.55 times by adding hydrochloric acid to adjust pH of the effluent liquid to equal to that of the original eluent and using the obtained liquid as the eluent repeatedly.

    • Chemical synthesis and spectroscopic properties of CdSe:Zn/ZnS core-shell quantumdots

      YANG Run, XIE Rui-Shi

      2017,54(2):357

      Abstract:

      Water–soluble CdSe:Zn/ZnS core-shell quantum dots were successfully synthesized in aqueous solution by a green synthetic route using a variety of ligands, and the effects of ligands on the structure and optical properties of the quantum dots were explored through a variety of analytical methods. XRD results show that the obtained CdSe:Zn/ZnS core-shell quantum dots possess cubic sphalerite structure of ZnS phase and their average grain size is about 2.4 nm, which is smaller compared with that of sample fabricated without ligands. SEM result shows that the shape of CdSe:Zn/ZnS is nearly spherical. Interestingly, the synthesized samples have good hydrophilicity, and the surfaces of the samples are coated with hydrophilic groups, which is consistent with the FT-IR results. Compared with the corresponding bulk materials, the absorption peaks of the quantum dots display a significant blue shift, demonstrating the obvious quantum confinement effect.

    • A comparative study of non-isothermal kinetics of fluoroether rubber under different atmosphere

      ZHAO Qi, zhang rong, PI Hong

      2017,54(2):364

      Abstract:

      The pyrolysis characteristics and kinetics of fluoroether rubber in air and nitrogen flow were studied by thermogravimetric analysis at five different heating rates. The kinetic parameters of the pyrolysis process were calculated using the method of Flynn-Wall-Ozawa and the mechanism of reaction were investigated using the method of Popescu. The results suggested that as the heating rates increasing, the pyrolysis temperature of the sample is moved to be higher. There is only one peak in DTG curves. The sample is more stable under nitrogen flow and the pyrolysis process of it is promoted by oxygen. It was found that the average value of the activity energy in air is 172.5kJ/mol, while 260.9kJ/mol in nitrogen. The pyrolysis process in air are well described by the model of Three dimension (R3) between 340°C and 370°C, by the model of Ginstling-Brounshtein (G-B) between 370°C and 380°C, and by the model of Zhuravlev (Zh) between 380°C and 400°C. While the thermal decomposition process in nitrogen are well described by the model of Ginstling-Brounshtein (G-B) between 400°C and 430°C, by the model of Three dimension (R3) between 430°C and 460°C.

    • Density functional study of norfloxacin

      SUN Ting-Ting, HUANG Ju, HE Wei-Ping, WANG De-Tang

      2017,54(5):1049

      Abstract:

      The molecule of norfloxacin was investigated with the density functional theory (DFT), and the molecular geometry was optimized by utilizing B3LYP method at the levels of 6-311+G(d,p). Based on the optimized geometry, the infrared absorption spectra (IR) and Raman scattering spectra (Raman), the frontier molecular orbital and the net charge distribution were calculated by the means of quantum mechanics. According to the calculation results of the infrared absorption spectra (IR) and Raman scattering spectra (Raman), characteristic vibrational frequencies of norfloxacin molecule were assigned. Based on the calculation results of the highest occupied orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and the net charge distribution, the characteristics of the highest occupied orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and the potential energy surface were discussed. Based on the molecular geometry was optimized by utilizing B3LYP method at the levels of 6-311+G(2d,p), and applying the theory of GIAO, the nuclear magnetic resonance (NMR) was obtained and the spectral data were analyzed and discussed.

    • The first principles calculation Visible light on photocatalytic properties of Main Group C-Si-codoped TiO2

      WANG Qing, WANG Shuai, DAI Jian-Feng, LI Wei-Xue

      2017,54(1):135

      Abstract:

      In this work, the electronic structures, charge density differenceand optical properties of Si and C codoped anatase TiO2 are studied by using the plane-wave ultrasoft pseudopotential method of density functional theory (DFT). The calculated results reveal that C-Si-codoped anatase TiO2 results in band gap narrowing that increases the probability of electronic transition from the impurity energy levels to the conduction band (about 1.7eV), then improves the solar energy utilization, the existence of impurity energy levels in the forbidden gap reduces the carrier transition energy. The C-Si-codoped TiO2 has been helpful for enhancing the absorption coefficient under visible-light region, especially, among the three models, the third model exhibits the largest value of absorption coefficient under visible-light region.

    • Study of Adsorption Characteristic of Uranium(Ⅵ) on Clay Rock

      LAI Jie, LIU Chang, LENG Yang-Chun, CHENG Jian-Feng, TUO Xian-Guo

      2017,54(4):815

      Abstract:

      In this paper, experimental study on static absorption was carried out for Alashan clay rock on Inner Mongolia. To explore the factors which may influence absorption characteristic of U(Ⅵ) on clay rock, including contact time, U(Ⅵ) initial concentration, solid-liquid ratio, pH value, ionic type and ionic concentration. The following results are obtained. The absorption rate of U(Ⅵ) on Alashan clay rock in Inner Mongolia is quite fast with adsorption equilibrium achieved in 24 hours. The optimum adsorption ratio is 1:200, and the optimum adsorption concentration is 160 μg•mL-1.The absorption capacity of clay rock was enlarged with the increasing of pH value. When pH value is at 8, the ability of absorption reaches the best. The absorption capacity of Uranium is largely hindered by Ca2+、CO32- and HCO3-, which have a great effect on the absorption ability of U(Ⅵ). The distribution coefficients of K+、Na+、Cl-、NO3-、SO42- can be changed with the change of ionic concentration, The surface adsorption of U(Ⅵ) on clay rock is dominated by inner-sphere complexation. The studies indicate the adsorption behavior of U(Ⅵ) on clay rock has a great significance on settling high level radioactive waste in China.

    • Study on the Interaction between Potassium Dehydroandrograpolide Succinate with Bovine Serum Albumin by Spectroscopic Methods

      LIU Li, CHENG Fei-Xiang

      2017,54(2):351

      Abstract:

      Dehydroandrograpolide Succinate (PDS) is a drug, widely used to treat viral pneumonia, viral upper respiratory tract infection such as anti-inflammatory drugs, known as the “Chinese medicine antibiotics”. Herein, Under the optimal conditions,fluorescence and absorption spectroscopy were used to study the interaction of PDS with bovine serum albumin (BSA) and effects of metal ions at different temperatures. The rate constant (Kq), apparent quenching constant (Ksv), binding constant (KA) and static fluorescence quenching association constant (KLB) and binding site number(n) were calculated using Stern-Volmer, Lineweaver–Burk and Double logarithm equations. The results show that PDS is able to bind to BSA. The probable quenching mechanism of BSA by PDS was mainly static quenching due to the formation of a PDS-BSA complex. The results of thermodynamic parameters indicate that electrostatic force plays the main role in the binding process and the binding process was spontaneous. The obtained data for binding sites of n approximately equal to 1 indicated that there was a single class of binding site for the BSA with PDS. The primary binding site for PDS was located at sub-domain ⅡA and ⅢA of BSA and near by tyrosine residue. There was almost no cooperative effect. The results obtained from synchronous fluorescence showed that the interaction between BSA and PDS caused the conformational changes of BSA. Pb2+, Mn2+, Ni2+and Cu2+ competed with the interaction of PDS with BSA, increasing medical effectiveness. Cr3+ promoted on interaction and prolonged drug effect time. The obtained results not only provided a theoretical basis for revealing the pharmacokinetics and further research on development of new anti virus herbs drugs.

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    Material Science
    • The magnetic model of the single-domain magnetite magnetoreception

      QIAN Xia

      2017,54(3):600

      Abstract:

      Many living beings can distinguish direction and position by using geomagnetic field, while biomagnetites can be found in these living beings, so scholars think that there are magnetoreceptions existing in these living beings which are formed by the biomagnetites and outer organic tissues (including the nerve). The magnetoreceptions interact with outer magnetic field and can transform the magnetic information into neural information, so these living beings can have response to it. The theories of biomagnetite magnetoreceptions include the model of single-domain magnetite magnetoreception and the model of superparamagnetic magnetite magnetoreception. In magnetotactic bacteria, there are many typical single-domain magnetites, so in this paper, the magnetic model and working mechanism of the single-domain magnetite magnetoreception are discussed qualitatively from the point of view of theory of magnetism taking the example of magnetotactic bacteria. In the outer magnetic field, each single-domain magnetite which is surround by biomembrane can be forced, and the single-domain magnetite transmits the force to the outer biomembrane and can be accepted by mechanical receptor in the biomembrane, then the force can be transformed into a stimulus signal which can cause the behavior of the bacteria; Another case may also exist, the single-domain magnetites combine with the biomembrane tightly, the force can open or close the ion passageway thereby influencing the inflow of ions and influencing the transmembrane potential, so stimulus signal can be produced; The signals can be magnified because many single-domain magnetites and biomembrane exist.

    • Absorption and scattering properties of gold nanotubes with an offset core

      ZHANG Xing-Fang, LIU Feng-Shou, YAN Xin, WEI De-Quan

      2018,55(1):0154

      Abstract:

      The effects of core offset, dielectric constants of core and embedding medium as well as incident light direction on the absorption and scattering properties of gold nanotubes with a nonconcentric core are theoretically studied by the finite difference time domain method. The numerical results show that the absorption and scattering spetra red shift and the absorption-scattering ratio increases with increasing core offset distant of the inner core from the nanotube centre. Moreover, the absorption-scattering ratio also increases with the increased core dielectric constant or the decreased dielectric constant of embedding medium. When the incident light direction is parallel to core offset direction, the greater absorption-scattering ratio appears as the position of the core is close to the incident light, but the ratio is smaller than that one when the incident light direction is perpendicular to offset direction as the core offest is given.

    • Microstructure evolution on tensile of tungsten nanowires with different crystal orientations of [110], [112] and [111]

      LU Min, YU Dong-Hai, LIU Chang-Ju

      2017,54(1):147

      Abstract:

      Mechanical properties and micro-structure fracture mechanism of tungsten nanowires with crystal orientation of [110],[112] and [111] have been investigated with molecular dynamics and embedded atom methods. Simultaneously common neighbor analysis, center symmetry parameters and coordination number has been employed to analysis the evolution of structure. It is concluded that different crystal orientation nanowires have different characters. The elastic modulus, yield strain, yield strength and the fracture stress is decreasing in the sequence of[111], [110]and [112] crystal orientations. It also reveal that all of the stress-strain curves are classified into four stages: elastic stage, damage stage, yielding stage and failure stage. It concluded that crystal orientation has slightly impact on the elastic modulus but has great effect on tensile strength, yield strength and ductility. Interestingly, hardening stage has been found in tungsten nanowire with crystal orientation of [112] at yielding stage. That is to say the strain increase with the stess increase in the hardening stage, the nanowire with crystal orientation of [112] has the trend that recover its capability in strength, but consequently result in the least ductility. In the end the tensile failure mechanisms of the three nanowires have been summarized.

    • g-C3N4 and P25 organic-inorganic composite for improved visible light-induced photocatalytic conversion of CO2

      WAN Li-Juan, YANG Ming

      2017,54(3):605

      Abstract:

      g-C3N4 and P25 organic-inorganic composite with varying the content of g-C3N4 has been synthesized through facile mixing and heating method. The composite was characterized by X-ray diffraction, high-resolution transmission electron microscopy (HRTEM) and UV-vis diffuse reflection spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and BET surface area measurements. The activity of composite photocatalyst g-C3N4-P25 with 60% or 80% g-C3N4 for photoreduction of CO2 is higher than that of either single-phase g-C3N4 or P25 under visible light irradiation. The as-prepared organic-inorganic composite exhibits an improved photocatalytic activity due to enhancement of electron–hole separations both at the interface and in the semiconductors.

    • New microwave synthesis of temperature sensitive carbon dots

      WANG Du-Liu, MA Rong, YANG Jian-Dong, YAN Xiang, WU Sheng-Ping, ZHANG Shao-Fei

      2018,55(6):1287

      Abstract:

      The carbon dots solution was prepared by the microwave method using citric acid and polyethylene glycol 200 as raw materials, which was characterized by laser dynamic light scattering, XRD, UV, TEM and fluorescence spectrophotometer. The experimental results show that the carbon dots produced are approximate spherical with better dispersity and without reunion phenomenon, and their sizes are about 5 nm. At the optimum excitation wavelength of 363 nm, the emission wavelength is 418 nm. With the increase of temperature, the emission peak position of the carbon dots solution does not move, but the intensity of fluorescence declines significantly. There is a good linear relationship between the fluorescence intensity and temperature, R2=0.9895. The carbon dots sensitive to temperature are expected to be used in some devices of fluorescent material of displaying and the measurement of surface temperature.

    • The synthesis of ZnTiO3/TiO2 composite photocatalysts and their photocatalytic performances

      LIU Leng, DU Yi-En, LI Jun, LIU Yu-Fang, CAI Xue-Mei, CHEN Yong-Qiang

      2018,55(4):827

      Abstract:

      The ZnTiO3/TiO2 composite photocatalysts with high photocatalytic activity were synthesized by hydrothermal treatment of the [Ti4O9]2ˉ nanosheets after it was adjusted to a desired pH value with a 3 mol/L HCl solution and a 3 mol/L NaOH solution in the present of hexamethylenetetramine and Zn(NO3)2. The [Ti4O9]2ˉ nanosheets were prepared by using the layered tetratitanate K2Ti4O9 as the processor. First, the K2Ti4O9 sample was converted into a protonic tetratitanate H2Ti4O9 by exchanging K+ of K2Ti4O9. And then the H2Ti4O9 was mixed with the triethanolamine (TEAOH) to obtain the TEA+-intercalated tetratitanate compound. Finally, the TEA+-intercalated tetratitanate compound was dispersed in massive amounts of distilled water to obtain the [Ti4O9]2ˉ nanosheets. The structures and morphologies of the ZnTiO3/TiO2 composite photocatalysts were investigated by using X-ray diffraction (XRD) and scanning electron diffraction microscopy (SEM). Furthermore, the photocatalytic activities of the synthesized ZnTiO3/TiO2 composite photocatalysts were also characterized. The experimental results revealed that the ZnTiO3/TiO2 composite photocatalyst obtained at the value of pH = 7.0 exhibits the higher photocatalytic activity.

    • Preparation and Characterization of V- doped Titanium Dioxide Films used for Dye-sensitized Solar Cell

      LAI Qi, LIAO Xian-Jie, ZHANG Shu-Li, LI Jun-Han, WU En-Hui, ZHANG Can-Yu

      2017,54(6):1289

      Abstract:

      In order to obtain high-performance batteries with titanium dioxide films by RF magnetron sputtering, doped(V2O5) TiO2 films were prepared. The main factors affecting the time,the pressure ratio of argon and oxygen, and annealing temperature. The effects such as mass of doping (V2O5) and annealing temperature on film properties.722 spectrophotometer using the optical properties of the study by the degradation of methylene blue and drop contact angle method on the catalytic properties of thin films and hydrophilic properties were studied. The results showed that Doped (V2O5) red shift the absorption peak of the film and the band gap narrowing, of which 0.5% V2O5 doped TiO2 thin film of the red shifts of the largest band gap becomes 2.88eV; 400℃ annealed films with good photocatalytic properties and ultra-hydrophilic.The prepared thin films of titanium dioxide as DSSC cells of sputtering time, the doping effect on battery performance. it shows that Doped with 0.5% V2O5 thin film battery open circuit voltage and short circuit current is higher than the undoped cell, in particular, short-circuit current increases from 24.82A to 88.15A.

    • Study on the mixing process of U-Mo microspheres and Al powders

      YU Zheng-Wei, WANG Lu-Quan, LIU Hai, LENG Mao-Lin, HUANG Jian-Min, GUO Zhen

      2017,54(2):371

      Abstract:

      U-Mo microspheres and Al powders were mixed by vertical planetary pot-classifying mixer. The influences of mixing time, mixing speed and filling rate on the mixing degree of mixed powders were studied systematically. The orthogonal experiment is designed to analyze the influence degree of the three factors on the mixing degree. The mixing degree and microstructure were discussed by variation coefficient method and stereomicroscope, respectively. Results show that optimal mixing process parameters: the mixing time of 90min, the mixing speed of 30r/min and the filling rate of 30%. The optimal mixed powders have a mixing degree of 93.6%. Three kinds of mixed factors impacting on the mixing degree have the order: mixing time < filling rate < mixing speed.

    • Study on the Supercapacitance Performance of Graphene Oxide-pristine SWNT composites

      CHEN Jian-Yu

      2017,54(1):156

      Abstract:

      Graphene Oxide-Pristine SWNT composites were fabricated using graphene oxide(GO) as a surfactant to directly disperse pristine SWNT, followed by a freeze-drying method of the sample. The morphology, structure, component and electrochemical property of the compounds were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and electrochemical measurements. The results showed that the electrochemical properties of the compounds were significantly improved due to the insertion of SWNTs into a GO matrix. Through changing the ratio between SWNTs and graphene oxide, the sample corresponding to a SWNT ratio of 10% showed the best supercapacitor property. At such a optimized mixing ratio, the specific capacitance of the nanocomposite was 155 F·g-1 at a current of 0.5A·g-1 in the KOH aqueous electrolyte of 6 mol·L-1 , which was 1.9-fold higher than that of pure graphene oxide (81.5F·g-1). These results clearly demonstrate that GO-SWNT composites prepared by our present simple method is very promising for next generation high-performance energy storage devices.

    • Preparation and Adsorption Performance of Porous Ceramic-based Lithium Ion Adsorbent

      ZHANG Li-Yuan, YANG Dong-Rui, ZHOU Da-Li

      2017,54(3):611

      Abstract:

      Li4Ti5O12 was synthesized by the sol-gel process under different conditions, and the as-prepared products were characterized by XRD in order to find out the ideal condition of preparing Li4Ti5O12. The precursor sol was loaded on porous ceramics synthesized from kaolin, talcum powder, alumina and carbon powder, and then Li4Ti5O12 based on porous ceramics was prepared after drying and calcination. Subsequently, porous ceramic-based lithium ion adsorbent was obtained by modification with hydrochloric acid, and then adsorptive capacity of the obtained product was measured. The results indicate that increasing calcination temperature and holding time is beneficial to the formation of Li4Ti5O12. The products with good crystallinity and purified crystal phase are obtained after a calcination at 750 ~ 800 ℃ for 5 ~ 8 h. The extraction rate of Li+ from Li4Ti5O12 and the adsorptive capacity are increased with the increment of calcination temperature and holding time. The Li+ drawn out ratio of the products calcined at 800 ℃ for 5 h is 51.7 %, and the adsorptive capacity reaches 12.2 mg Li+/g Li4Ti5O12.

    • The effect of moving metal wall on microwave heating uniformity

      ZHANG Chun, XIAO Guang-Nian, YANG Yang, HONG Tao, ZHU Hua-Cheng, HUANG Ka-Ma

      2017,54(5):1062

      Abstract:

      In this paper, the phase of electromagnetic field distribution in the cavity is regulated through movements of the metal wall of a rectangular waveguide, which can avoid the inhomogeneous heating caused by the uneven distribution of electromagnetic field in the rectangular waveguide. And the time varying medium method based on space coordinate transformation is proposed to calculate the moving boundary problem, which has a significant effect on solving the moving boundary problem of large industrial microwave cavities. A single mode BJ-22 wave guide heating system is used as the reference in this paper to analyze impacts of short circuit plane position on microwave heating uniformity. Experiments and calculation results show that the uniformity of microwave heating can be greatly improved by regulating of short circuit plane position, and the space coordinate transformation method can be used to calculate the moving boundary of the microwave cavity.

    • The magnetic model of the superparamagnetic magnetite magnetoreception

      QIAN Xia

      2017,54(6):1295

      Abstract:

      The model of biomagnetite magnetoreceptions include the model of single-domain magnetite magnetoreception and the model of superparamagnetic magnetite magnetoreception. In honeybees, there are many typical superparamagnetic magnetites, so in this paper, the magnetic model and working mechanism of the superparamagnetic magnetite magnetoreception are discussed qualitatively from the point of view of theory of magnetism taking the example of honeybees. In the outer magnetic field, each superparamagnetic magnetite can be act on with the size extend or contract along different directions. Superparamagnetic magnetites transmit the force and change of size to the outer biomembrane and eukaryotic cytoskeleton which embedding in the nervous system, so a nerve signal can be produced. The signals can be magnified because many superparamagnetic magnetites exist.

    • Effect of temperature and He cumulative damage on Er2O3 film phase structure and crystallinity

      SHI Yun-Long, LAO Yuan-Xia, WANG Ling, ZHANG Hai-Bing, DENG Ai-Hong, WANG Yuan

      2016,53(6):1340

      Abstract:

      In this paper, Er2O3 films are prepared in mixing atmosphere by radio frequency magnetron sputtering method. The phase structures, surface and cross-section morphologies of Er2O3films are characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The results show that the phase structure of the pure Er2O3 film is still stable under the annealed temperature of 500℃. However, with the annealing temperature increasing, the monoclinic phase of the Er2O3 film can transform into cubic phase at 700℃. In addition, for the Er2O3 film with He containing, the degree of crystallinity may be affected by He atoms. He bubbles can not be formed with small amount of He doped in, and the diffraction peak of the Er2O3 film decreased obviously comparing with that of the pure Er2O3 film. As the content of the doped He atoms increase, the monoclinic phase of the Er2O3 film becomes more stable under the high internal pressure due to the forming of He bubbles.

    • Synthesis of Fe2O3 photoanode with improved photoelectrochemical performance by surface electrochemical pretreatment and Ti-doping

      WAN Li-Juan, ZHANG Li, YANG Ming

      2018,55(5):1083

      Abstract:

      Ti-doped Fe2O3 photoanode was obtained through metal–organic decomposition method. The physical and photophysical properties of the hematite photoanode were investigated by X-ray diffraction (XRD), UV-vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) and the photo-electrochemical performance was evaluated for the Ti-doped Fe2O3 photoanode. In terms of maximizing the photoelectrochemical performances of the Ti-doped Fe2O3 photoanodes, the doping concentration of titanium was optimized. The Ti-doped Fe2O3 photoanode exhibits improved photoelectrochemical performance after the electrochemical surface pretreatment. The photoelctrochemical response of hematite photoanode can be improved by both titanium doping and the electrochemical surface pretreatment. Based on the analysis of the Mott–Schottky plots and electrochemical impedance spectra (EIS), a possible mechanism was proposed to explain the reason for the enhancement of photocurrent.

    • Preparation of hydrophobic Humic Acid Ester Ether (HAEE) and its mechanisms of the remediation for chlornitrofen

      MA Chong-Di, LIU Qian, LI Yue, SHEN Yue-Yue, ZHAO Shi-Lin

      2017,54(4):822

      Abstract:

      Chlornitrofen is a diphenyl ether herbicide, which is a typical persistent organic pollutant and has been widely used in 70~90 years in twentieth Century. Although it has been banned for 20 years, chlornitrofen still exists in water and soil systems, which has the potential threats to the agro-ecology systems. In the present study, humic acid ester ether (HAEE) was synthesized via regulating the dosage of glycerol triglycidyl ether while humic acid ester (HAE) was uniting as raw material. HAEE was analyzed by the analysis methods of Fourier transform infrared spectroscopy and contact angles. The results indicated that hydrophobic HAEE has the structure of humic acid and the characteristic functional groups of HAE. The adsorption characteristics and mechanisms of HAEE to chlornitrofen were investigated via a series of batch equilibrium experiments. As the results showed, the hydrophobic angle is increased from 30 to 96 degrees before modification. The degree of hydrophobic of HAEE is positively correlated with the adsorption capacity of chlornitrofen, and equilibrium reached after 2.0 h. The kinetics of adsorption is described well by the pseudo-second-order model, and Freundlich models are more suitable for the sorption isotherm. The adsorption capacity reduces gradually after 5 cycles. The removal rate is still above 78%. The adsorption mechanisms are π-π interaction and hydrophobic distributional effects. Adsorbent prepared by this method may provide a novel approach for remediation of chlornitrofen in aqueous-soil environment.

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    Invited Articles
    • Spatial and temporal analysis on public opinion evolution of epidemic situation about novel coronavirus pneumonia based on micro blog data

      CHEN Xing Shu, CHANG Tian You, WANG Hai Zhou, ZHAO Zhi Long, ZHANG Jie

      2020,57(2):409

      Abstract:

      Relying on 60 thousand blogs and 15 thousand hot blog reviews in Sina micro-blog from January 1st to February 29th in 2020, this article launches the analysis of the public opinion to the topic about novel coronavirus pneumonia based on distributed crawler technology, distributed database system, SnowNLP sentiment analysis model and K-Means algorithm. This analysis can show visually the spatial and temporal evolution process of Internet public opinion in the events of this epidemic situation. On spatial dimension, the netizens' attitude towards this pneumonia epidemic has roughly gone through three periods. The first period appears in the shape of bigger fluctuation which presents as tension and anxiety. The second period appears in the shape of rising slowly which presents as unity and excitement. The third period appears in the shape of slight fluctuation which presents as confidence and stability. On the whole, it shows the emotional state that positive is greater than negative and Optimism is greater than pessimism. On spatial dimension, we find that the area which has the most serious epidemic has the most comments and the lowest emotional value through geographical statistical analysis.

    • Computational Jurisprudence: An emerging interdisciplinary branch

      ZHANG Ni, PU Yi-Fei

      2019,56(6):1187

      Abstract:

      The application of state-of-the-art artificial intelligence to the law has led to a promising area of interdisciplinary research: computational jurisprudence. By investigating legal relationships through simulation and modeling with transforming the legal information analysis to real-time online intelligent system, computational jurisprudence is not simply to simulate the methods of natural science, but a deep integration of computational thinking and legal thought. With distributed real-time computing, computational jurisprudence aims to reveal the intrinsic essence behind legal system to improve the judicial efficiency, promote legislative feasibility and also reduce the conflicts in legal system.

    • Evolvement from Jurimetrics, computational law to cognitive law

      ZHANG Ni, PU Yi-Fei

      2021,58(2):020001

      Abstract:

      The paper discusses the impact of natural sciences such as artificial intelligence technology to Jurimetrics, computational law (or computational jurisprudence) and cognitive law (or cognitive jurisprudence) from the perspective of technological development and interdisciplinary. It first proposes the theory and definition of cognitive law, including its research scope, studying meanings and academic discipline, and teases out the relationships among Jurimetrics, computational law and cognitive law. To reduce the subjectivity and provide the objective reference for the vague expression in legal system, some quantitative methods, computational intelligence and cognitive intelligence are applied to legal system successively. However, legal information is open textured and semantic vagueness, and it is difficult to express all kinds of tacit knowledge, process knowledge and fuzzy knowledge by computer symbol system. Cognitive intelligence stresses to improve the ability of intelligent systems to understand data, express knowledge, reason logically and learn by themselves. Following the footsteps of technology, it will be the inevitable trend stepping from Jurimetrics and computational law to cognitive law. Cognitive law improves the understanding of legal rules and analysis of legal behavior, and enhances the interpretability of intelligent judgments by utilizing cognitive intelligence. As the sub-branch of cognitive social science, cognitive law will improve traditional legal theories, promote the deeply integration of the Common law system and the civil law system, and is expected to be a new interdisciplinary subject.

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    Chemistry and Material Science
    • Graphene-CsPbBr3 quantum dots photodetectors with high responsivity

      WANG Jing, SHI Rui-Ying, ZHU Guo-Dong

      2021,58(2):025001

      Abstract:

      All-inorganic perovskites, such as CsPbX3 (X = Cl, Br, I), are gaining increasing attention due to their outstanding optoelectronic properties, especially their higher thermal stability comparing with organic-inorganic hybrid perovskites. However, CsPbX3-based photodetector demonstrated a relatively low responsivity due to the low carrier mobility of perovskite films. In this work, we synthesize CsPbBr3 quantum dots and construct a hybrid graphene-CsPbBr3 quantum dots photodetector with a responsivity of 3.5×104 A W-1, by introducing graphene as a transport layer. The unprecedented performance is attributed to the effective charge transfer and photogating effect, high mobility of graphene and prolonged carrier lifetime.

    • Research on pesticide treatment efficiency of constructed wetland-microbial fuel cell coupling system

      JIANG Song-He, PIAO Wen-Hua, JIN Ming-Ji

      2021,58(6):065001

      Abstract:

      In this study, a constructed wetland-microbial fuel cell system was constructed to treat pesticides represented by Atrazine, and to understand the pesticide treatment efficiency and treatment mechanism of the system. The results show that the system has a good treatment performance for Atrazine. When the concentration of Atrazine is less than 4 mg/L, the treatment performance of the system remains stable above 85%. Under the condition of Atrazine concentration of 4 mg/L, the system has the best power generation performance. At this time, the average daily voltage, maximum power density and current density of the system output are 284.4 mV, 19.64 mW/m3 and 46.09 mA/m3, respectively. Pesticides have a significant impact on the microbial diversity of the system, but have no significant impact on microbial gene function, and have less impact on system bacteria than the electric field. The dominant bacteria phylum of the system includes the Proteobacteria, and the dominant electrochemically active bacteria includes the Bacteroides and Firmicutes, while the dominant bacteria phylum degrading pesticides includes the Actinobacteria, the dominant bacteria classes includes Alphaproteobacteria and Actinobacteria, and the dominant bacteria genus includes Christensenellaceae_R-7_group.

    • Microstructures and hot compression behavior of Mg-4Sn-1Ce alloy

      WU Ying, ZENG Qiang, HU Guang-Shan, WEN Tong

      2021,58(1):015001

      Abstract:

      The microstructures and hot compression behavior of Mg-4Sn-1Ce alloy were studied by optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and hot simulation test. The results shown that the as-cast alloy is mainly composed of island-like “island” shaped α-Mg、Mg2Sn、Ce4Sn5 and MgSnCe phases with the strain rate range of 0.001~1 s-1 and temperature range of 250~450 ℃ hot compression. The hot deformation activation energy Q is 162.03 kJ/mol. When the hot compression temperature increases from 250 to 450 ℃, the microstructures of tested alloy evolve from (compressed grains+extruded streamlines) to recrystallized equiaxed grains.

    • Quantitative detection of several heavy metals by modified surface enhanced Raman substrate

      TAN Xiong, LIU Xian-Bo, BAI Hong-Jie, CUI Xu-Dong, LIU Tong

      2021,58(1):015002

      Abstract:

      Heavy metal ions have a serious impact on water quality and its application, and the development of a highly selective and sensitive detection platform for heavy metal ions has great significance in the water resources protection. The surface-enhanced Raman (SERS) sol substrate was prepared by using 4-MBA to modified gold nanoparticles as a carrier, which has strong selectivity and high sensitivity to heavy metal ions such as Pb2+, Cd2+, and As3+ in aqueous solution. The experiments found that the Raman detection spectra of Pb2+, Cd2+ and As3+ by the SERS substrate have obvious shifts in vibration frequency bands and peak intensities near 1046cm-1, 1075cm-1, and 1587cm-1. An optimized enhanced substrate was obtained by optimizing the sol-substrate, which can distinguish three kinds of heavy metal ions. The detection limit for heavy metal ions can reach 0.1mg/L, and it has a linear relationship in the range of 0.5 to 100 mg/L. A standard addition verification experiment was performed on Pb2+ in real water samples. This substrate provides a fast and convenient method for heavy metal identification and detection with better enhancement effect and heavy metal quantitative analysis ability, and provides an effective means for the efficient detection of heavy metal ions in water.

    • Numerical simulation of biomass grate furnace combustion based on FLIC

      XIAO Fan, HU Nan, ZHANG Man, JIN Yan, YANG Hai-Rui

      2021,58(2):025002

      Abstract:

      Based on the FLIC simulation platform, we have performed a numerical simulation study on a 7 MW biomass layer fired hot air boiler in Northeast China. The simulation results show that the biomass layer can be roughly divided into three stages, the water evaporation section (0~0.5 m), the volatile emission combustion section (0.5~2.1 m) and the fixed carbon combustion section (1.0~2.8 m). The volatile content of this fuel is relatively high, the thickness of the bed after its precipitation is significantly reduced, and the primary air temperature is too low, resulting in a low fixed carbon burnout rate, so the primary air temperature can be appropriately increased. According to the characteristics of the fuel in different combustion stages, the air can be supplied on demand. For example, 80% to 90% of the total volume can be provided during the volatiles escape combustion stage, and 10% to 20% of the total air can be provided during the fixed carbon combustion stage. This improves the fuel combustion efficiency, and can optimize the structure of the arch angle and the furnace arch coverage length according to the flue gas temperature, and enhance the ignition and burnout of the furnace arch. According to the simulation results, it is proposed to optimize the primary air and the air supply scheme to make the combustion more adequate.

    • First-principles study of the properties of Au-Ag nanotube encapsulated into carbon nanotube

      SUN Ya-Ru, MA Liang-Cai

      2021,58(3):035001

      Abstract:

      By using first-principles calculation based on density-functional theory, we have systematically investigated the stability, electronic and mechanical properties of (4, 2) Au-Ag alloy nanotubes encapsulated in a series of zigzag (n, 0) carbon nanotubes with various diameters. The most stable combined system with larger filling rate is AuxAg4-x@(15, 0) with an optimal tube-tube distance of about 4.20 ?. The analysis of band structure shows that the quantum conductance of the composite system is much higher than that of the corresponding isolated alloy nanotubes. The energy states near the Fermi level are mainly attributed to the s electrons of the inner Au and Ag atoms as well as the p electrons of the outer C atoms. The critical strains and the ideal strengths of the combined systems are remarkably higher than those of the freestanding alloy nanotubes, suggesting that the mechanical properties of the alloy nanotubes are signi?cantly enhanced by the carbon nanotube coating.

    • The effect of high temperature treatment on the structure of sodium bentonite montmorillonite

      QIN Ya-Ting, PENG Tong-Jiang, SUN Hong-Juan, ZHOU Can, CHAO Li

      2021,58(3):035002

      Abstract:

      The bentonite from Wuhu, Anhui (WH), Santai, Sichuan (ST), and Xinyang, Henan (XY) were used as the raw material, and sodium carbonate was used as a modifying agent to modify three raw materials (named as WH-G, XY-G and ST-G), then the sodium samples were heat-treated at high temperature. The phase, structure, thermal properties and spectral characteristics of samples were characterized and analyzed. The results showed that the temperature of the montmorillonite losing adsorbed water and interlayer water in the three samples WH-G, XY-G and ST-G increase with the increase of the layer charge number of the montmorillonite in the samples, but its thermal stability is opposite. The structures of montmorillonite WH-G and XY-G samples are completely destroyed at 900 °C, while the structure of montmorillonite of ST-G sample is completely destroyed at 800 °C.

    • Preparation of a novel chitosan magnetic material and its adsorption mechanism towards dyes

      TIAN Tian, ZHANG Ling-Lin

      2021,58(4):045002

      Abstract:

      In order to effectively solve the environmental pollution caused by dye wastewater, a copper ion chelated chitosan magnetic composite was prepared for the adsorption of dye wastewater. The composite Cu@CTS@Fe3O4 was successfully prepared by the coordination chelation of chitosan with copper ion and the introduction of magnetic particles Fe3O4. The structure and morphology of the prepared materials were characterized by FTIR, SEM and TGA. At the same time, the adsorption kinetics and isotherm adsorption of reactive brilliant red (RBR) were studied in detail. The adsorption experiments showed that the adsorption capacity of Cu@CTS@ Fe3O4 to RBR reached the maximum of 831.22 mg/g when pH=2. This study provides some relevant data and theoretical guidance for the application of chitosan-based adsorbents in the field of dye wastewater treatment.

    • Study on the evolution and protection of decarburization in 300M steel

      WEI Ming-Gang, LUO Heng-Jun, ZHANG Hai-Cheng, DENG Hao, Lü Xiao-Gen, CHEN Long-Qing, TANG Jun, XIE Jing

      2021,58(6):065002

      Abstract:

      300M steel is an important material for fabricating main bearing structure of aircrafts. However, the surface oxidation and decarburization of this material will occur in varying degrees during the heat treatment of die forging process, which seriously affects the yield of forgings. Herein, the decarburization behavior of 300M steel under different heat treatment conditions is systematically studied. The morphology and thickness of the oxide layer are analyzed by scanning electron microscope (SEM) and the corresponding Energy Dispersive Spectrometer (EDS). The variation of decarburization depth is measured using microhardness method. The evolution of decarburization behavior of 300M steel under different heat treatment conditions is clarified, and the effect of anti-oxidation coating on the depth of decarburization layer is presented. The results show that the dense oxide layer formed on the surface of 300M steel during heat treatment has distinct protective effect, which can prevent the matrix carbon from diffusing to the surface, thus reduce the depth of decarburization layer. There is a balance between the diffusion rate of carbon and the surface oxidation rate at different temperatures, and the application of anti-oxidant coating on the surface of 300M steel will change the original balance. The results of microstructure analysis show that the full decarburization zone on the surface of 300M steel is composed by pearlite or ferrite, and the semi-decarburization zone is mainly martensite and precipitated carbide. We also expound the evolution of the near-surface microstructure of 300M steel with the increase of holding time. Finally, the coupling mechanism of decarburization and oxidation on the surface of 300M steel is revealed from the perspective of thermodynamics. The results of this paper are expected to provide important data and theoretical support for establishing optimization process of die forging and developing heat treatment protection technology of 300M steel.

    • Synergistic tuning of microstructure and thermoelectric performance of bismuth telluride based materials by ball milling

      LIU Sheng-Cun, CHEN Long, WANG Zheng-Shang

      2021,58(5):055002

      Abstract:

      Bismuth telluride compounds are thermoelectric materials with the best performance near room temperature, which have important application value in waste heat recovery and solid state refrigeration. The main preparation method is ball grind milling, and slight changes of various parameters may affect the microstructure and thermoelectric properties of materials. Ball milling time, as an important ball grinding parameter, can not only affect the refinement of powder particle size, but also regulate the thermoelectric properties of materials. Therefore, it is urgent to analyze the influence of ball milling time on the crystal structure, particle size and the thermoelectric performance of products. In this paper, bismuth telluride compounds were prepared by adjusting different ball milling time with constant ball grinding speed. The response of grains to ball milling time is found through the analysis of crystal structure and powder particle size. The result of subsequent thermoelectric performance tests shows that, with the increase of ball milling time, the change of particle size leads to the synergistic tuning of electron and phonon transport. Finally, the maximum ZT merit of n-type and p-type bismuth telluride were increased to 0.91 and 1.11, respectively. This study systematically summarizes the influence of ball milling time on the microstructure and the thermoelectric capability of bismuth telluride. Our work shows the significance in the mergence of powder metallurgy and thermoelectrics, which may play some roles in the commercial application of thermoelectric conversion technology.

    • Simulation and performance study on the four type substrates of domestic thick gaseous electron multiplier

      YAN Jia-Qing, XIE Yu-Guang, DENG Shan-Qiao, ZHEN Zhi-Yang

      2021,58(5):055001

      Abstract:

      Ceramic-based Thick Gaseous Electron Multipliers (THGEMs) have been successfully applied to neutron detection. The influences of ceramic, FR4, kapton, and PTFE substrates on the thermal neutron scattering and absorption were studied and compared by Geant4 software. The ceramic-THGEMs, FR4-THGEMs, kapton-THGEMs and PTFE-THGEMs are homemade in PCB factory, which have the same geometric parameters such as aperture of 200 μm, hole spacing of 600 μm, thickness of 200 μm, insulation ring width of 80 μm, and sensitive area of 50 mm × 50 mm. The gas gain, energy resolution and gain stability were measured using 5.9 keV X-rays, four different type substrates THGEM can work normally. The maximum gain of a single and double layer ceramic THGEMs reach 1.2×104 and 4×104 in Ar + CO2 =80:20, respectively. The energy resolution is better than 24.4% in Ar + iC4H10 = 97:3. Good gain stability was obtained during a more than 100 hours continuous test. By using a 239Pu source, the alpha deposited energy spectrum and gain curve of the ceramic THGEM were measured.

    • Determination of Maleic acid in solution and food additives by fluorescence

      YU Shan-Shan, TIAN Jun

      2022,59(1):015001

      Abstract:

      In the face of ever-increasing food safety issues, the detection of bad additives is critical. In order to achieve the effective detection of maleic acid in food additives, we propose to use compound 1 (2,2’-diformyl-1,1’-binaphthyl) to indentify maleic acid by fluorescent. The conditions of fluorescence detection are explored in detail in detail, and the results show that the best fluorescence enhancement effect is obtained in methanol. The calculations predict the low detection limit (1.3×10-7 mol/L), which indicates that it has potential application prospect. Finally, maleic acid in starchy foods was successfully detected by using this probe.

    • Study on leaching blast furnace dust with deep eutectic solvent and electrodepositing zinc

      HUANG Ping, ZHANG Yuan, WU En-Hui, ZHANG Sheng-Qian, GUO Wen-Ming, SHI Ming-Chuan

      2022,59(1):015002

      Abstract:

      The choline chloride-urea deep eutectic solvent system was used to leach blast furnace dust, and then zinc was obtained by direct electrodeposition. The effects of liquid-solid ratio, leaching time, and stirring speed on the leaching rate of zinc were investigated. After the leaching experiment, the cyclic voltammetry and electrodeposition experiments were carried out, respectively. The experimental results showed that the leaching rate of zinc reaches 71% under the conditions of liquid-solid ratio of 10 mL/g, the leaching time of 30 h, the stirring speed of 300 r/min, and the temperature of 70 ℃. The cyclic voltammetry test confirmed that the reduction potential was -1.4 V. X-ray diffraction and energy spectrum analysis showed that the coating was metallic zinc with high purity. By analyzing the morphology of the coating, it was found that the zinc coating was composed of cluster grains of about 1 μm.

    • Preparation and properties of Ymer N120 modified non-ionic waterborne epoxy emulsion

      SUN Shi-Xiong, CHEN Ya-Jun, ZHANG Ming-Hui, ZHAO Ben-Bo, DENG Ping, CHENG Yuan

      2022,59(4):045002

      Abstract:

      In order to overcome the disadvantage of low content of epoxy group and solid in current waterborne epoxy (WEP) emulsion, polyethylene glycol 400 (PEG400) was used as soft section to prepare non-ionec WEP emulsion firstly. Then, the modified non-ionic waterborne epoxy (YWEP) emulsion was synthesized with the side hydrophilic chain extender (Ymer N120). The effects of the dosage of Ymer N120 on the properties of YWEP emulsion and paint film were studied. The results showed that the epoxy group content (represented by epoxy value) of the WEP emulsion could be increased as high as 0.36, and the solid content pof YWEP emulsion increased by 73.3% from 30% to 52% while maintaining the high expoxy value. After curing, the tensile strength of the film increases from 57.3 MPa to 64.8 MPa. The corrosion current density decreased from7.97E-8 mA*cm-2 to 9.99E-9 mA*cm-2. In conclusion, the transfer of hydrophilic groups from the main chain to the side group can effectively improve the properties of waterborne epoxy emulsions, coatings and coatings.

    • Influence of sulfuric acid treatment on the structure and morphology of illite and montmorillonite

      ZHOU Can, SUN Hong-Juan, PENG Tong-Jiang, ZHANG Qi

      2022,59(2):025001

      Abstract:

      In the structures of the illite and montmorillonite, because the amount of Al3+ replacing Si4+ in the tetrahedrons is different, the number of layer charge is different, and the degrees of damage to the structure during acid treatment are also different. In this work, two raw materials, Zhejiang Anji bentonite and Jilin Antu illite, were respectively acid treated with sulfuric acid and hydrogen peroxide for comparative experimental study. The phases, structures, thermal properties, spectroscopic properties and microscopic morphologies of the raw were characterized and analyzed. The results show that the montmorillonite structure of the montmorillonite sample is destroyed when the acid treatment concentration is 2 mol/L. With the increase of the acid treatment concentration, the surface of the lamellae changes from smooth and flat to edge curling to collapse between layers; The structure and morphology of illite of the sample are basically intact when the acid treatment concentration is 6 mol/L, and the acid corrosion resistance of montmorillonite is not as good as that of illite. The results in this study are of significance to the application and development of illite and montmorillonite.

    • Rapid detection of potassium sorbate by nitrogen-doped carbon quantum dots fluorescence probe

      SUN Xue-Hua, QIANG Yu, HAO Du-Ting, ZHAO Ying-Jie, ZHAO Rong-Rong

      2022,59(2):025002

      Abstract:

      Potassium sorbate is an acidic food preservative, which can effectively inhibit the activity of mold, yeast and aerobic bacteria, prolong the storage time of food, and maintain the original flavor of food. In this study, fluorescence nitrogen doped carbon quantum dots (NCQDs) with good water solubility was synthesized by one-step hydrothermal method. Based on the effective quenching of NCQDs by potassium sorbate, a fluorescence probe for rapid detection of potassium sorbate was constructed. Under the optimal experimental conditions, the concentration of potassium sorbate showed a good linear relationship with the fluorescence quenching intensity of NCQDs in the range of 3.0×10-5~ 1.0×10-4 mol/L and 1.0×10-7~3.0×10-5 mol/L, and the detection limit was 9.5×10-8 mol/L. It has been used for the determination of potassium sorbate in soda water and white vinegar with the recoveries of 98.25%~102.7% and 98.33%~101.8%.

    • Adsorption of polyvinylpyrrolidone on Ag surface and mechanism of selective growth of Ag nanostructures

      LIU Bo, SUN Hong-Juan, PENG Tong-Jiang, HE Rong, ZHU Wen-Kun

      2022,59(4):045001

      Abstract:

      To elucidate the mechanism of selective growth of Ag nanowires in capping agents, we investigated and the interaction between polyvinylpyrrolidone (PVP) molecules and various Ag crystal surfaces by first-principles calculations. The results show that PVP molecules severely affect the stability of Ag surfaces. Only Ag (200) and Ag (111) facets well maintain their structures upon the absorption of PVP molecules, suggesting their preferential growth in this capping agent. With the increase of PVP concentration, the binding of PVP molecules to the Ag (200) facet becomes stronger than that of Ag (111), which may facilitate the formation of Ag (200) nanostructure. The regulation mechanism of long-chain PVP molecules on Ag (200) nanostructures is mainly governed by the van der Waals force as well as the chemical bonding between ketone oxygen and Ag atoms.

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    Education Teaching Reserch
    • Recognizing learners' personality traits based on programming behaviors and its application explorations

      Lin Tao, Zhou Xiaohan, Wu Zhiming, HONG Mei, WANG Jian, TANG Ning-Jiu

      2021,58(5):057002

      Abstract:

      How to perform individualized programming teaching is an important issue in educational practice, and how to recognize the personality of learners is the key for this issue. In this paper, the method of recognizing personality is proposed based on the programming behaviors of learners. Specifically, the programming behavior features of learners are first extracted from multiple aspects; then the classification models are established using the support vector machine; finally, the multi-task voting strategy is used to comprehensively identify learners' personality traits. The results show that the traits in the Big Five Model can be predicted using the proposed method, verifying the feasibility of using programming behaviors to identify learners’ personality to a certain extent; in addition, this paper also discusses the applications of the proposed method in future programming education.

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    Interdisciplinarity
    • Research on the impact of informal governance in the innovation ecosystem on the symbiosis of system members

      GAO Jia-Xin, WANG Tao, GU Xin

      2021,58(6):067003

      Abstract:

      Informal governance can coordinate symbiotic relationships and behaviors among members, promote interdependence and interaction among members, and promote the healthy symbiotic development and value co-creation of the innovation ecosystem. Based on the social embedding theory and organizational ecology, this paper summarizes four types of informal governance: trust, reputation, cooperative culture, and joint sanctions based on existing research. Using the Logistic model, we construct a symbiosis model of the informal governance influence on the symbiosis relations evolution among members of the innovation ecosystem from the perspective of symbiosis theory, and conduct evolutionary stability analysis and simulation of the symbiosis model. The research results show that the symbiosis evolution of members of the innovation ecosystem depends on the strength of the symbiosis coefficient between members. Among them, the symbiosis coefficient of trust, reputation, and cooperative culture has a positive impact on the symbiosis evolution of system members, which is conducive to the formation of mutual symbiosis. The impact of joint sanctions on the symbiosis and evolution of system members is both positive and negative, which may produce parasitic, partial or reciprocal symbiosis. The income of the symbiosis and stable state of system members is affected by the symbiosis coefficient of informal governance and the maximum income of the main body. Informal governance affects the evolution of enterprises in the innovation ecosystem to a mutually beneficial symbiosis relationship, and provides enlightenment for the formulation of informal governance of enterprises, the realization of value co-creation and the healthy operation of cooperation and symbiosis of the innovation ecosystem.

    • Investigating the impact of risk attitude and privacy protection on consumers' data sharing behavior

      QIN Jun-Chang, WANG Yuan, DONG Yu-Cheng

      2021,58(6):067002

      Abstract:

      Promoting the sharing of big data is the key to development and prosperity of the sharing economy, and it is of great practical significance to study the influence mechanism of data sharing. Based on consumers' risk attitudes and corporate privacy protection methods, this paper constructs a game model of data sharing between enterprises and consumers, in which the mechanism that affects data sharing behavior is analyzed and specific policies are recommended. The main findings of this paper are: (1) the risk-biased consumers’ data sharing behavior is mainly affected by factors such as data leakage losses and data protection cost differences. (2) The risk aversion of risk-averse consumers is highly correlated with the game results of data sharing. For the consumers who have a moderate level of risk aversion, there are dual equilibria when the loss caused by data leakage is greater than the difference between the cost of high and low privacy data protection. (3) When the proportion of risk-biased consumers is high, the behavior of risk-averse consumers to use the high quality of sharing data will be increased, while the enterprises will reduce the high-quality protection behavior on protecting consumers' privacy.

    • Model and algorithm for vehicle routing problem with spatial-temporal correlated stochastic travel times

      ZHANG Dong-Qing, GUO Zhao-Xia, ZHANG Yin-Jie

      2021,58(6):067001

      Abstract:

      This paper studies a version of vehicle routing problem with spatial-temporal correlated stochastic travel times in real road networks. First,a two-stage stochastic optimization model is established for this problem. An intelligent stochastic optimization method is then proposed to solve the model, in which an efficient intelligent optimization algorithm is developed to find candidate solutions, and the scenario generation technology is adopted to generate spatial-temporal correlated stochastic travel time scenarios to evaluate the solutions. This paper proposes a hybrid particle swarm optimization algorithm combined with a variable neighbourhood descent algorithm to perform effective optimization. Finally, a series of testing instances are established based on the road network of Beijing to verify the effectiveness of the hybrid particle swarm optimization algorithm. The experimental results show that considering the spatial-temporal correlation of stochastic vehicle travel times in real traffic environment will affect the best vehicle routing decisions.

    • Optimized Housing Price Prediction Based on XGBoost

      TAO Ran

      2022,59(3):037001

      Abstract:

      Objectively, housing prices are restricted by many factors and because of this, house price prediction remains a very classical and challenging problem in data analysis. In response to the redundancy of house price data, which makes it difficult to identify important features in practical scenarios, this paper proposes an innovative approach to data pre-processing and data prediction by means of double model iterative fitting. The initial data is pre-processed in terms of data meaning, data form and data relevance, then suitable models are selected for training. In traditional machine learning, Random Forest (RF) and XGBoost (XGB) are two commonly used methods. The RF model is able to accurately judge "redundant" features through its Bagging process. The XGB model, while improving prediction, is also limited by its reduced generalisation ability and cannot stably reflect the importance of features. Therefore, this paper uses the RF model to process redundant data and uses the XGB model to fit new data sets to improve the prediction results. In this paper, experiments were conducted on the Kaggle competition dataset ("House Prices Advanced Regression Techniques") and the test results showed that the final regression accuracy R2 of the XGB regression model was 87%, while the R2 of the single RF model and the single XGB model were 79.2% and 78.7%, respectively. The experiment proves that the data prediction method can significantly improve the effect of housing price prediction. To fully reflect the model fitting effect and prediction ability, the authors change the "house price" to discrete variable which has two categories of "high" and "low", and get the Confusion Matrix with an precision of 93% and a recall of 93%.

    • Two-period equilibrium model and pricing strategy with trade-in for duopoly

      LI Hui-Zhong, YIN Yi-Xi, PANG Qi, WU Peng

      2022,59(3):037002

      Abstract:

      Trade-in is a popular marketing method in the current age, making enterprises face new challenges in market competition. This study sets up a two-period duopoly model with differentiated manufacturers considering trade-in offers. The manufacturers determine their trade-in prices and maximize their profits. The equilibrium and corresponding results are then analyzed. The results show that: (1) When the products are significantly differentiated and the depreciation coefficient is moderate, the model has a unique equilibrium and market segmentation. (2) The high-quality manufacturer benefits from his own product quality standards, and his competitiveness of not participating in the trade-in market is stronger when the depreciation coefficient is large. (3) Consumers will pay more attention to the manufacturers’ product quality market positioning, because it’s important for consumers to decide whether to participate in trade-in during the second period. Therefore, enterprises should consider external factors in advance before trade-in strategies.

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