• Issue 2,2020 Table of Contents
    Select All
    Display Type: |
    • >Special Column: National Young Scholar/Local Science Foundation
    • Design of bionic prototype milli-micro Newton level two-dimensional force test system

      2020, 41(2):105-113. DOI: 10.7535/hbkd.2020yx02001

      Abstract (958) HTML (0) PDF 2.94 M (1157) Comment (0) Favorites

      Abstract:In mechanical bionics field, it is necessary to measure the bionic prototypes generated milli-micro force. To satisfy the test requirement, a milli-micro Newton two-dimensional force measuring system was designed. Hardware of the system mainly includes self-developed parallel double spring cantilevers and its matched eddy current displacement sensors, milli-micro force measurement platforms which can realize the easy installation of samples, transducer output signal conditioning module and data sampling card, and data processing and displaying program based on LabVIEW. To test the system function, the system operation debugging was implemented. The friction force, the normal force, and the piercing resistance force provided by the bionic prototypes were measured. The results confirm that the system can obtain these force values with milli-micro magnitude accurately, and display these force values in real time and intuitively in the interface window, as well as realize the storage of these force values in the form of force trajectory diagram and data group effectively. Accuracy and range of this milli-micro Newton two-dimensional force measuring system is respectively up to 50 μN and 800 mN. Our designed system can accurately measure the milli-micro Newton two-dimensional force produced by bionic prototypes, and provide the technique and method of force measurement used in mechanical bionics.

    • >Mechanical, Electronics and Information Science
    • Construction of hybrid airspace strategy based on multi-scale analytic hierarchy process

      2020, 41(2):114-121. DOI: 10.7535/hbkd.2020yx02002

      Abstract (837) HTML (0) PDF 863.20 K (637) Comment (0) Favorites

      Abstract:Considering the possible flight issues due to multiple aircrafts performing tasks in the same airspace in the future, an evaluation index system for the optimal avoidance scheme of large UAVs in mixed airspaces was constructed by studying various scenarios of possible collisions, and a hybrid airspace strategy of multi-scale analytic hierarchy process was proposed by analyzing the pros and cons of different scale methods. First, a large-scale unmanned aerial vehicle was used as a research object to establish a hybrid airspace model, which classified various birds or aircraft that have the possibility of conflict with the UAV in the mixed airspace, and considered the factors of collision risk level and the target execution task level. Secondly, the multi-scale analytic hierarchy process was used to obtain the weights of various avoidance targets in different situations, and the consistency was determined. The membership function was further introduced, and the final result was further weighted by analyzing the obtained weights. Finally, the airspace environment that large drones may encounter in the airspace is analyzed to verify whether the drone avoidance decision plan is effective. The verification results show that the determined multi-scale analytic hierarchy process can meet the establishment of the avoidance strategy in a complex airspace environment, and has a dynamic effect to meet the needs of UAVs to construct and adjust the avoidance strategy in real time. The research result provides new ideas for drones to complete avoidance strategies and safe flight under complex airspace conditions.

    • Cooperative trajectory planning of multi-unmanned aerial vehicle based on improved Gauss pseudospectral method

      2020, 41(2):122-132. DOI: 10.7535/hbkd.2020yx02003

      Abstract (923) HTML (0) PDF 2.71 M (1176) Comment (0) Favorites

      Abstract:In order to solve the problems of large computation amount, long operation time and difficulty in ensuring optima-lity, an improved method combining particle swarm optimization algorithm and Gaussian pseudospectral method was proposed. Firstly, particle swarm optimization algorithm was used for track pre-planning to ensure the fast realization of approximate optimal solution. Secondly, according to the selection of relative positions of collocation points of Gaussian pseudospectral method, the path points of pre-planned particle swarm optimization were fitted, which was used as the initial reference instruction of Gaussian pseudospectral method, so as to solve the problem of initial value sensitivity of pseudospectral method and accelerate the convergence speed of optimization algorithm. Finally, simulation experiments were carried out by taking the performance index of unmanned aerial vehicle formation, flight environment and cooperative flight constraints into consideration. Simulation results verify the importance of the selection of initial value and show that the designed algorithm could improve the optimization and convergence speed of the solution. The research results can be used to quickly plan multi-dimensional and high-precision guidance instructions for coordinated flight control of multiple UAVs, and have certain reference value for the realization of intelligent autonomous flight.

    • A survey of information network representation learning

      2020, 41(2):133-147. DOI: 10.7535/hbkd.2020yx02004

      Abstract (1042) HTML (0) PDF 2.89 M (1847) Comment (0) Favorites

      Abstract:The network representation learning algorithm represents the information network as a low-dimensional dense real vector carrying the characteristic information of network nodes, and is applied to the input of downstream machine learning tasks. With the development of machine learning and deep learning, network representation learning has been widely used due to its powerful modeling capabilities and extensive applications. The network representation learning methods and their application were summarized. Firstly, the current network representation learning methods at home and abroad were categorized into different groups, including traditional methods, network structure-based embedding, embedding with attribute information, and spectral-based Graph Convolutional Networks, spatial-based Graph Convolutional Networks and Graph Attention Networks. Then various models were expounded, and the applicability and characteristics of the models were compared. Secondly, the related applications of network representation learning, including recommender system and biomedical field, were introduced. Commonly used data sets are also given, and open source implementations of representation learning models and powerful graph deep learning libraries for reference were organized. Finally, the developing trend of network representation learning was summarized and forecasted. Deep graph neural network, dynamic and heterogeneous network representation, and generalization ability of network model will need to be further studied.

    • >校内投稿:数学
    • Variation of sum of two largest eigenvalues of the distance matrices of four-leaf graph

      2020, 41(2):148-157. DOI: 10.7535/hbkd.2020yx02000

      Abstract (960) HTML (0) PDF 959.78 K (870) Comment (0) Favorites

      Abstract:In order to accurately obtain the extremum of the distance eigenvalues of fowr-leaf graphs under tow graph transformations in any case, two graph transformations of four-leaf graphs and the results of the above problems were given by using the properties of the determinant, the Vieta theorem and the reduction of inequality. Firstly, the distance matrices, the distance Laplacian matrices and the distance signless Laplacian matrices of three kinds of four-leaf graphs before and after the transformation were given. The characteristic polynomials were obtained by using the properties of the determinant. The number of positive and negative roots of three kinds of distance characteristic polynomials was determined by the Vieta theorem. The range of eigenvalues was estimated by the reduction of inequality. Thus, the range of the sum of the two maximum eigenvalues was obtained. Finally, the two maximum eigenvalues of three kinds of distance matrices of four-leaf graphs before and after the transformations were compared. The comparison shows that the sum of the two maximum eigenvalues of four-leaf graph increases after two transformations. The results provide a research method for the extremum problems of distance eigenvalues of special graphs, and have certain reference value for the research of moleculer stability.

    • >Chemistry and Chemical Industry
    • Synthesis of Suvorexant

      2020, 41(2):158-163. DOI: 10.7535/hbkd.2020yx02005

      Abstract (1200) HTML (0) PDF 975.38 K (1363) Comment (0) Favorites

      Abstract:In order to explore the synthetic route of Suvorexant, simplify experimental process and clarify the physicochemical properties and spectral data of intermediates, the synthetic method of Suvorexant was studied. The target compound was synthesized from 2-amino-5-methylbenzoic acid, followed by diazotization reaction, iodination reaction, Ullmann reaction, amidation reaction, deprotection reaction, and nucleophilic substitution reaction. By optimizing the synthesis parameters, Suvorexant and intermediates can be directly obtained by using recrystallization method instead of column chromatography purification. The results show as follows: Hydrochloric acid aqueous solution is used as the solvent in the diazotization reaction and the iodination reaction, n(2-amino-5-methylbenzoic acid)∶n(sodium nitrite)∶n(potassium iodide)=1∶1.2∶1.4, the yield is 92.31%; N, N-dimethylformamide is used as the solvent in the Ullmann reaction, n(2- iodine -5-methylbenzoic acid)∶n(2H-1,2,3-triazole)∶n(copper iodide)=1∶2∶0.05, the yield is 63.47%. Acetonitrile is used as the solvent in the deprotection reaction, n((R)5- methyl -4-(5- methyl -2-(2H-1,2,3- triazol -2- yl) benzoyl) -1,4- diaza -1- carboxylic acid tert-butyl ester)∶n(p-toluenesulfonic acid)=1∶1.2, the yield is 93.02%. The total yield of the route is 47.99% after optimization, and the purity is 99.89%. The structure of the target compound is confirmed by 1H-NMR and 13C-NMR. The optimized route has advantages of mild reaction conditions and simple process and workup operation, which is suitable for industrial production.

    • Study on adsorption properties of zeolites for VOCs and microwave desorption

      2020, 41(2):164-171. DOI: 10.7535/hbkd.2020yx02006

      Abstract (897) HTML (0) PDF 2.01 M (720) Comment (0) Favorites

      Abstract:In order to screen zeolites suitable for adsorption of VOCs and microwave desorption, and to study the performance influencing factors such as pore size, aluminum-oxygen tetrahedron, balanced cations, seven kinds of adsorbents (K-A, Na-A, Ca-A, Ca-X, Na-X, Na-Y and Na-ZSM5 zeolites) and three kinds of VOCs adsorbent (benzene, methanol, n-hexane) were experimentally studied, and the pore size, specific surface area, pore volume and cell parameters of the zeolite were tested by BET and XRD characterization methods. The results show that the adsorption capacity is higher when the pore size of the zeolite is larger and the polarity of the VOCs is larger; when different aluminum-oxygen tetrahedral structure content (Na-X, Na-Y, Na-A and Na-ZSM5) and different balanced cations (K-A, Na-A, Ca-A and Ca-X, Na-X) zeolites microwave desorption are used, the zeolites with a high content of aluminum-oxygen tetrahedron structure is more suitable for microwave desorption, and the zeolites with a balanced cation of Na+ is stronger than with K+ and Ca2+, after 5 cycles of static adsorption and microwave desorption, the zeolites microwave desorption has stable structure and performance. The research results can provide important reference for the industrial application of the new method of zeolites adsorption of VOCs and microwave desorption.

    • >Transportation & Logistics
    • Real-time estimation of road friction coefficient in different road conditions

      2020, 41(2):172-180. DOI: 10.7535/hbkd.2020yx02007

      Abstract (1003) HTML (0) PDF 1.64 M (1329) Comment (0) Favorites

      Abstract:In order to accurately estimate the road adhesion coefficient under different road conditions and improve the safety and stability of vehicles, a method was proposed to estimate the road adhesion coefficient based on the front and rear wheels speed and braking torque under braking conditions. First, considering the transfer of front and rear axle load, the modelling was completed in Matlab/Simulink software to create a dynamic model of the two-wheel vehicle braking.Secondly, the control target was determined as the ideal and actual slip ratio of the front and rear wheels of the vehicle, and the ideal braking torque sliding mode controller was established. The chattering phenomenon of the sliding mode controller was properly dealt with through the integral switching surface. Finally, the front and rear wheel speed and braking torque were used as input to design the extended state observer, which is used to observe the correlation value of the road adhesion coefficient. The results show that the road adhesion coefficient in all kinds of road conditions can be accurately estimated by the above method, and the extended state observer can resist the external interference and has strong robustness. The successful application of the extended state observer provides the reference for the design of vehicle stability control system.

    • >Special Column: New Energy Resources, Energy Conservation and Environmental Protection
    • Research summary of modification of nickel-rich ternary layered transition metal oxides positive materials

      2020, 41(2):181-190. DOI: 10.7535/hbkd.2020yx02008

      Abstract (1092) HTML (0) PDF 2.29 M (1202) Comment (0) Favorites

      Abstract:Nickel-rich ternary layered transition metal oxide positive materials have attracted much attention due to their high specific capacity, low price and environmental friendliness. However, the material itself has problems such as cyclic capacity degradation, which are caused by Li/Ni mixing, phase change reaction, gas generation, microcracks, transition metal dissolution and surface structure changes. In order to solve the problems of rapid capacity degradation and poor high-temperature performance of positive materials, modification methods of nickel-rich ternary layered transition metal oxide positive materials at home and abroad in recent years were summarized, including optimization methods such as surface coating material synthesis, element doping material preparation, core-shell structure material development, and concentration gradient material design, etc. It is pointed out that the wide application of high nickel layered transition metal oxide anode materials needs to start from the aspects of continuously improving the material preparation method, changing the material properties, and reducing the material cost, etc. to develop high energy density lithium ion batteries, so that nickel-rich ternary layered transition metal oxide anode materials can be applied in the field of power batteries as soon as possible.

    • Multi-objective analysis of distributed energy system under different operation strategies

      2020, 41(2):191-200. DOI: 10.7535/hbkd.2020yx02009

      Abstract (834) HTML (0) PDF 2.48 M (689) Comment (0) Favorites

      Abstract:In order to seek the coordination of energy supply system in economy, security, environmental protection and energy conservation, relying on the "Internet plus", a distributed cooling, heating and power system integrated with power generation unit (PGU), ground source heat pump and energy storage system was constructed. The models about off-design condition of each device were illustrated. On this basis, four operation strategies were put forward: following electric load, following thermal load, following hybrid load and following max efficiency of PGU. Then operation cost, carbon dioxide emission and primary energy were employed as objectives to analyze the operating time, output and performances of the proposed system under off-design condition. The results show that the proposed system has better economy, lower emissions and lower primary energy consumption than the conventional separate system. Under FTL strategy, the operation cost and carbon dioxide emission are the lowest, which are reduced by 32.7% and 45.3%, respectively. Because of the continuous operating, the reduction of primary energy is the most, which is 86.7%. The results can provide some theoretical references for the operation of distributed system.

Editor in chief:朱立光

Inauguration:

International standard number:ISSN 1008-1542

Unified domestic issue:CN 13-1225/TS

Domestic postal code:

  • Most Read
  • Most Cited
  • Most Downloaded
Press search
Search term
From To