Editor in chief：朱立光
International standard number：ISSN 1008-1542
Unified domestic issue：CN 13-1225/TS
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2021, 42(3):205-213. DOI: 10.7535/hbkd.2021yx03001
Abstract:Depending on the excellent functional body structure obtained by the natural evolution, many animals have become bionic prototypes, which provide effective solutions for complex problems in the engineering field. The milli-micro Newton level force measurement technology of bionic prototype can provide the necessary testing instrument for revealing the locomotion mechanical mechanism of these bionic prototypes. Starting from the excellent functional characteristic of typical bionic prototypes, the research progress of milli-micro Newton level force measurement technology for quantitative characterization of the locomotion function and material physical properties of bionic prototypes was summarized. Especially, the principle and function of force measurement system with sensor, the principle and function of centrifugal movement force measurement system and the principle and function of image processing force measurement system were analyzed. Three aspects are pointed out some important aspects that bionic prototype milli-micro Newton level force measurement technology should focus on in the future:the force measurement system with sensor should improve the dynamic response characteristicsand test accuracy, in order to accurately characterizethe motion propertyof the biomimetic prototype; the centrifugal movement force measurement system shouldpromote the accuracy of test platform speed information collection and the imagedefinition of high-speed camera, in order to accurately characterize interaction between the micro-bionic prototype and material surface;theimage processing force measurement systemshould consider how to accurately extract micro-displacement information from images, in order to improve the test precision and accuracyof the force measurement system.
2021, 42(3):214-221. DOI: 10.7535/hbkd.2021yx03002
Abstract:Aiming at the problems of low precision and complicated operation of traditional bullet trace detection which generally uses laser to detect rifling traces to extract the signal of the rifling traces,new extraction and handling method was provided.By adopting multi-scale registration,elastic shape measurement and convolutional neural network technology,and using multi-mode elastic drive based adaptive control method,the end position and attitude parameter distribution model of the specimen were established.At the same time,the isolated forest algorithm was used to detect the signal for anomaly processing,[JP2]and the variable-scale morphological filtering algorithm was[JP] used to remove non-small features.The square velocity function was introduced to optimize the elastic shape measurement algorithm to complete the curve contour embedding layer mapping.Aiming at the matching part of the rifle line shape,a convolutional neural network model of optimized parameter sharing connection triples suitable for trace features was established,and the network was trained to convergence by calculating the similarity of the embedding layer and minimizing the triple loss function.The comparison of similarity matching experiment results by using different methods was conducted.The results show that the new method solves the accuracy and operability problems faced in the traditional bullet trace detection,the stability of the detection result can be guaranteed,and the cost is greatly reduced compared with the traditional detection method.Adopting multi-mode elastic drive adaptive control method and three-tuple convolutional neural network model in the extraction of rifling traces provides a new feasible method and idea for bullet trace detection.
2021, 42(3):222-230. DOI: 10.7535/hbkd.2021yx03003
Abstract:In order to take into account the availability of shared location data and privacy protection requirements,aiming at the shared location information collected by the third party,a location privacy protection scheme of LBS users was proposed based on differential privacy.Firstly,the shared location data set was preprocessed,the dictionary query mode was used to build the location transaction database,and the trie tree structure was adopted to store the location data and frequency,so as to improve the query efficiency and reduce the number of noise.Secondly,frequent location selection was carried out in the Trie tree,and Laplacian mechanism under differential privacy was used to disturb the location frequency.Finally,the perturbed data was optimized based on the two techniques of upward post-processing and consistency constrained post-processing,and theoretically prove that the proposed scheme satisfies ε[KG-*4]-differential privacy.The experimental results show that,compared with the existing methods,this scheme improves the efficiency of data processing,generalizes the sensitive locations,and has higher accuracy and lower rejection rate.This scheme has a certain reference value in user location privacy protection and shared location data availability.
2021, 42(3):231-240. DOI: 10.7535/hbkd.2021yx03004
Abstract:Community structure is an important field in the research of complex networks,and it is also one of the important characteristics of complex networks.It is found that the community structure in the network plays an important role in understanding network functions.Through in-depth research on the literature of heterogeneous network community discovery at home and abroad,a more comprehensive summary of the existing heterogeneous network community discovery algorithm is carried out.Firstly,by summarizing the literature of heterogeneous network community discovery at home and abroad,the basic overview of heterogeneous network community discovery is given,and the basic definition of related issues in the field of heterogeneous network community discovery is defined.Then,it introduces the heterogeneous network community discovery algorithm and the main evaluation index,and classifies the existing methods by using different network structures and algorithms.Finally,the development trend of heterogeneous network community discovery algorithms is summarized and prospected,and the future research focus can be focused on the following aspects:1) Exploring the evaluation criteria of community discovery based on heterogeneous networks to promote the rapid development of this field Development;2) Design a more general algorithm model to solve the problem of the number of unknown communities caused by prior knowledge;3) Carry out more research on dynamic networks.
2021, 42(3):241-247. DOI: 10.7535/hbkd.2021yx03005
Abstract:Aiming at the problems of insufficient computing speed and poor portability in the miniaturization and parallelization of convolutional neural network,this paper proposes a design of high-speed universal convolutional layer IP core using VHDL language based on the characteristics of convolutional neural network and FPGA devices.Layer based on convolution calculation,convolution core design is put forward for the parallel calculation and pipeline module,through each line in the convolution of the core connect to FIFO to improve the data flow,reduce the operating address jump,and join the control core to make it can adjust the convolution with images and convolution window size to layer parameters,generate different convolution layer,finally,the convolution layer is combined with the AXIS protocol and encapsulated into IP core.Under the working frequency of 50 MHz,the convolution calculation of 100×100 images with 2×2 convolution check is carried out.The utilization rate of each resource is less than 1%,and the time is 204 μs.The theoretical calculation speed can reach the maximum of 5 MF/s.[JP]The IP core structure of the convolutional layer not only increases the portability of the convolutional module,but also ensures the computing speed,which provides a feasible implementation method for the implementation of convolutional neural network on miniaturized devices.
2021, 42(3):248-256. DOI: 10.7535/hbkd.2021yx03006
Abstract:Brushless direct current (BLDC) motors have been widely used in industry and factory automations, and electric vehicles. Interturn short circuit fault is one of the dominated faults for a BLDC motor, and this fault affects precision control, induces noise and vibration, and even causes motor burn down and fires. Hence, diagnosis of interturn short circuit fault of BLDC motor is of significance. This paper proposes a method that combines of transfer learning and features fitting to realize accurate fault localization and evaluation. First, the three-phase current signals of the motor stator windings are synchronously sampled. The one-dimensional current signals are transformed to an image, and then a transfer learning-based convolutional neural networks model is trained for fault localization. When the fault phase has been localized, the sensitive features are extracted and selected from the corresponding phase current, and then features fitting method is designed to qualitative evaluate the fault levels. Experimental results indicate that the proposed method can localize the faults with accuracy of 100%, and the relative average error of fault quantitative assessment is 4.33%. The proposed method shows potential applications for accurate localization and evaluation of stator winding faults in permanent magnet motor systems.
2021, 42(3):257-264. DOI: 10.7535/hbkd.2021yx03007
Abstract:In order to solve the problem that the fault line cannot be accurately identified after single-phase grounding fault occurs in power grid,an intelligent sensing method of residual current grounding fault based on wavelet packet decomposition was proposed.Based on wavelet analysis and intelligent sensing principle,the residual current generated by grounding fault was collected,and the collected residual current information was analyzed and compared to sense the grounding fault and identify the fault.By researching on-line monitoring of residual current of AC power supply and arc grounding fault diagnosis technology which is based on wavelet transform,the time-frequency characteristics of current obtained by wavelet packet decomposition were used for fault line selection;the fault line selection method based on the proposed wavelet packet decomposition was simulated.The results show that the time-frequency information can be extracted accurately and the fault line can be determined effectively by using the method,and the fault line can be accurately identified with the difference of current characteristics between fault line and normal line.The research result provides a reference for the design of intelligent sensing system of AC power grounding fault.
2021, 42(3):265-270. DOI: 10.7535/hbkd.2021yx03008
Abstract:In order to solve the problems of out-of-date synthesis process and lag-behind quality control standards of naphazoline hydrochloride,the synthesis process of aimed product was studied.According to the relevant regulation of ICH Q11 on the development and manufacture of drug substances,the modified synthesis route was designed to control the generation of impurities based on the concept of quality by design.Using 1-naphthylacetic acid as the starting material,the target compound was obtained through amidation reaction,amide dehydration reaction,catalytic addition-cyclization reaction and salt formation reaction.The results show as follows:In the amidation reaction,using dichloromethane as the solvent,n(1-naphthylacetic acid)∶n(di-tert-butyl dicarbonate)∶n(ammonia)=1∶12∶12,the yield is 886％;In the dehydration reaction and the addition-cyclization reaction,N,N-dimethylformamide is used as the solvent,the workup procedure is simple and the intermediate purity is high;In the salt formation reaction,n(naphazoline free base)∶n(36％ hydrochloric acid)=1∶148,the yield is 901％.The overall yield of the four-step reaction after optimization of the reaction conditions was 5083%.The four impurities listed in the European Pharmacopoeia were not detected in the product,and no new impurities were produced.The synthesis process have advantages of mild reaction condition and operational simplicity,so the result provide a theoretical basis for the industrial production of naphazoline hydrochloride.
2021, 42(3):271-279. DOI: 10.7535/hbkd.2021yx03009
Abstract:With the advance of ecological civilization construction,the domestic demand for green environmental protection is also higher and higher.As an important chemical intermediate,the traditional preparation method of pyrouric acid has some problems such as environmental pollution,so it is urgent to study and popularize the new preparation method.The process and characteristics of solid phase and liquid phase methods for the preparation of pyrouric acid were systematically reviewed.The problems of traditional preparation methods such as bad operating environment,high energy consumption and not up to the standard of environmental protection were elucidated.The development prospect of preparation methods of pyrouric acid was also prospected.It is pointed out that further research on the preparation of pyrouric acid can be carried out in the following aspects.1)It is necessary to carry out research on rotary kiln and fluidized bed equipment,gradually [JP2]replace tunnel kiln,[JP]realize the upgrading of technical equipment,and overcome the shortcomings of traditional solid phase method;2)In order to lay a foundation for industrial production,the selection and recovery of solvent system in liquid phase method should be deeply explored,and the research of liquid phase method in small scale and scale up in pilot scale should be strengthened;3)The raw material source,product yield and production cost of the new preparation method should be systematically and deeply studied in order to realize large-scale production.
2021, 42(3):280-286. DOI: 10.7535/hbkd.2021yx03010
Abstract:In order to solve the problem that the size of the synthesized metal nanowires is single and the magnetic property is limited due to the limitation of the diameter of the anodic aluminum oxide (AAO) pore,anodic alumina (AAO) templates with different pore sizes were prepared by twice anodic oxidation method, and then Ni nanowire arrays were grown in AAO templates with different pore sizes by template-assisted electrodeposition method.The morphology, microstructure and composition of the prepared Ni nanowire arrays were characterized by SEM, TEM, XRD and EDS techniques. The magnetic properties of Ni nanowires were investigated by physical property measurement system (PPMS).The results show that the growth mechanism of Ni nanowires is the interaction between the reduction of positive half period Ni2+ by alternating current and the dissolution of negative half period Ni atoms. Ni nanowires have magnetic anisotropy, and with the increase of the diameter, the easy magnetization direction of Ni nanowires gradually changes from parallel to the axis of the nanowire to perpendicular to the axis of the nanowire. The change of easy magnetization direction is caused by the change of the effective anisotropic field and the magnetic domain structure with the diameter of the nanowire.The study of electrodeposition Ni nanowire arrays and their magnetic properties can provide theoretical and experimental basis for further study of the growth mechanism and magnetization mechanism of magnetic nanowires prepared by alternating current electrodeposition, it lays a foundation for widening the application field of magnetic nanowire.
2021, 42(3):287-295. DOI: 10.7535/hbkd.2021yx03011
Abstract:When Q215 strip steel is used to coil square tube in iron and steel plant,serious cracking is easy to occur at bending point.In order to reduce the cracking rate of the steel pipe,the causes of the corner cracking of the steel pipe were analyzed from two aspects of the microstructure and the inclusions in the steel pipe.The influence mechanism of the microstructure transformation on the cold deformation properties of medium-carbon and low-carbon steel was discussed.The reasonable hot rolling and cooling processes after rolling were formulated.The properties of the inclusions and microstructure in Q215 steel were analyzed by optical microscope and scanning electron microscope.The transformation point,CCT and TTT curves of Q215 steel were calculated by J Mat Pro software.The results show that the main reason for the cracking of the steel pipe is the existence of ter-tiary cementite precipitated along the ferrite grain boundary in the steel,which belongs to hard brittle phase and causes stress concentration at the grain boundary during bending deformation,and the secondary reason for the cracking is the existence of large-size sulfide inclusions more than 100 μm in the steel.By adjusting the hot rolling and cooling process parameters,the amount of tertiary cementite in the steel is significantly reduced,the amount of pearlite is increased,and the cracking rate of the steel pipe is significantly reduced.The research results provide a reference for preventing the processing cracking of Q215 and similar steel grades.
2021, 42(3):296-303. DOI: 10.7535/hbkd.2021yx03012
Abstract:In order to solve the problem of poor oxidation resistance of Cu-Ni-Fe inert anode at high temperature during aluminum electrolysis,Cu-20Ni-19Fe-xAl alloys (x=0%,6%,8%,10%) with different Al contents were prepared by vacuum melting method,and the alloys were used for the high temperature oxidation experiments which were carried out at 850 ℃ with oxygen partial pressure of 1.013×105 Pa and oxidation time of 100 h,and the effects of Al addition on the microstructure and high temperature oxidation properties of the alloy were investigated.The results show that the as-cast Cu-20Ni-19Fe alloy is composed of Ni/Fe-rich dendritic phase (γ1) and Cu/Ni-rich matrix phase (γ2);Al was dissolved in the Cu-20Ni-19Fe alloy matrix with 6% content of Al added;The needle-like or blocky NiAl phase was formed in the microstructure of Cu-20Ni-19Fe alloy with 8% and 10% Al added;The content of NiAl phase increases with the increasing addition of Al;The oxidation kinetics of Cu-20Ni-19Fe alloy follow the straight line under 850 ℃ and oxygen partial pressure of 1.013×105 Pa;After the addition of Al,the oxidation kinetic curve of Cu-20Ni-19Fe-xAl alloy follow an exponential law,and the oxidation rate index of the Cu-20Ni-19Fe-xAl alloy was much smaller with more content of Al.The high-temperature oxidation resistance of Cu-20Ni-19Fe alloy was greatly improved by the addition of Al,which proves the Cu-20Ni-19Fe alloy may be used as an alternative anode material for aluminum electrolysis.
2021, 42(3):304-310. DOI: 10.7535/hbkd.2021yx03013
Abstract:In order to solve the problems of porosity,slag inclusion,shrinkage porosity,etc.,the influence of low pressure casting process parameters on filling and solidification of the AlSi9Mg gearbox shell was studied.Two different gating systems of the three-dimensional solid model were drawn with Pro/Engineer software,and the influence of pouring temperature,mold temperature and filling pressure on the alloy filling and solidification process during low pressure casting of the AlSi9Mg gearbox shell were studied through the method of numerical simulation using ProCAST software.Based on the experimental results,effective analysis was conducted with orthogonal test table.The result shows that the reasonable process parameters are as follows:Pouring temperature 700 ℃,mold temperature 350 ℃ and filling pressure 45 kPa,and under these process parameters,the defect volume of shrinkage pore of the casting is reduced from 1537 cm3 to 1425 cm3.The research on simulation and optimization of low-pressure casting process of AlSi9Mg gearbox lower shell can provide reference for optimization of low-pressure casting process of gearbox lower shell,and has practical application value.
2021, 42(3):311-318. DOI: 10.7535/hbkd.2021yx03014
Abstract:Aiming at the problem that when the finite element software is used to analyze the influence of multi parameter changes on the research object,it is necessary to repeatedly model,define and modify parameters,an improved programming method and graphical user interface establishment method were provided.Taking the dynamic shear extrusion connection of intermediate billet as an example,the python language was used for secondary development of ABAQUS pretreatment,and the kernel script of dynamic shear extrusion connection simulation was programmed.Then the graphic user interface of dynamic shear extrusion connection was established by using RSG plug-in.Finally,simulation analysis was conducted.The results show that users can input different process parameters,die parameters and blank parameters according to the actual situation to complete the pre-processing operation automatically,which not only effectively solves the problems of complicated and error prone model assembly,but also improves the accuracy of model assembly and simulation results,so the feasibility of the secondary development program and graphical user interface is verified.The study provides a powerful tool for the follow-up study of the influence of different reduction,overlap,edge width and other parameters on the dynamic shear connection quality of intermediate billet,and provides a reference for the secondary development of ABAQUS in other fields.