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2021, 41(5): .

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2021, 41(5): .

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Abstract:

Influence of Transverse and Longitudinal Grooves on Semi-Preformed Warhead Fragment Formation

LI Guojie, SUN Kai, WANG Junlin, ZHANG Hanyu, WANG Wei, FENG Shunshan

2021, 41(5): 451-458. doi:10.15918/j.tbit1001-0645.2020.019

Abstract(874) PDF(417)

Abstract:
In order to analyze the influence of shell grooves on the fragment formation of semi- preformed warhead, the simulation calculation of different working conditions was carried out, and the experimental verification of typical working conditions was carried out. Using ANSYS/LS-DYNA finite element analysis software, the fracture law of fragments under explosive load was studied, and the influence of the shape and depth of transverse and longitudinal grooves on the fragment formation was obtained. The results show that more fragments will be formed when only transverse grooves are used. When only longitudinal grooves are used, rod fragments will be formed. When the transverse grooves and the longitudinal grooves are prefabricated at the same time, the depth of the longitudinal grooves should be less than 20% than that of the transverse grooves, so that fragments of uniform size and controllable quality can be obtained. When the groove shape is "V+V" or "saw tooth (inclined to the starting point) +V", the fragmentation control effect is better. The experimental study on typical working conditions was also carried out. The experimental results are similar to the simulation results, which proves the correctness of the simulation rules.

Dynamic Spherical Cavity Expansion Theory of Soil Considering Moisture Content and Dry Density

WU Haijun, ZENG Feiyin, LI Jinzhu, PI Aiguo

2021, 41(5): 459-464. doi:10.15918/j.tbit1001-0645.2020.090

Abstract(662) PDF(261)

Abstract:
In order to study the influence of soil moisture content and dry density on the penetration resistance of the projectile, the Mohr-Coulomb yield condition of soil was modified by introducing moisture content and dry density, the dynamic spherical cavity expansion theory of material was deduced, and the target resistance function was obtained. Based on this, experiment data in existing research were calculated, and they were and compared with the data in this experiment and other empirical formulas. The results show that the radial stress decreases with the increase of water content and increases with the increase of dry density in the process of penetration; compared with the results of empirical formulas and other models, the calculation model considering the dry density of water content has better prediction accuracy and can be used for the calculation of penetration depth of low-speed penetration soil.

Analysis of Pentration and Blast Combined Damage Effects of Reactive Material Jet

YU Qingbo, GUO Zhirong, ZHONG Shiwei, ZHAO Hongwei, GE Chao

2021, 41(5): 465-473. doi:10.15918/j.tbit1001-0645.2020.093

Abstract(724) PDF(501)

Abstract:
In order to analyze the combined damage effects of reactive material jet penetration and blast, the change of blast effect during reactive material jet penetration was studied by combining experimental research and theoretical analysis. Vented chamber calorimetry (VCC) experiments were carried out to investigate the characteristics of implosion overpressure after the reaction material jet penetrated steel targets of different thicknesses, and the influence of the thickness of the penetration target plate on the penetration morphology of the reaction material jet and the peak value of the implosion overpressure was analyzed. Based on the virtual origin theory, a micro-element model was developed to describe the process of reactive material jet explosion. The results show that the overpressure formed by the reaction material jet in the tank has the characteristics of large peak value, long action time and uniform spatial distribution, and there is an incomplete reaction part in the forming reaction material jet. The density attenuation of the reactive material jet greatly increases the mass of the jet consumed by the subsequent jet penetrating per unit length, resulting in a parabolic attenuation of the implosion overpressure peak with increasing penetration depth. The model can be used to describe the relationship between the blast effect and the penetration depth when the reactive material jet impacts the target, which provides help for analyzing the damage mechanism of the reactive material jet.

Dynamic Response of Fixed Circular Plate Subjected to Dynamic Explosion Shock Wave

RONG Jili, LIU Dongbing, ZHAO Zitong, WANG Xi, WU Zhipei, LI Furong

2021, 41(5): 474-479. doi:10.15918/j.tbit1001-0645.2020.140

Abstract(809) PDF(292)

Abstract:
In order to study the influence of charge speed on the damage power of explosion shock wave, Autodyn software was used to simulate the deformation of armored steel circular target plate under dynamic explosion shock wave, the theoretical calculation model of central deflection of armored steel circular target plate under dynamic explosion shock wave was established, and the simulation results were compared with the theoretical calculation results. The results show that the overpressure peak of the explosion shock wave along the direction of charge velocity is greatly increased and the propagation speed of the explosion shock wave along the direction of charge velocity is accelerated. The theoretical calculation model can accurately calculate the central deflection of the fixed circular target plate under dynamic explosion shock wave, and has universal applicability.

A Stochastic Model Predictive Control Algorithm for Electric Vehicle Air-Conditioning System

GUAN Jifu, ZHAO Yufeng, ZHAN Yuan, CAO Li

2021, 41(5): 480-486. doi:10.15918/j.tbit1001-0645.2020.091

Abstract(870) PDF(385)

Abstract:
A stochastic model predictive control(SMPC) algorithm based on Markov chain was proposed to improve the energy efficiency of the AC(air-conditioning) system. Due to the significant influence of heat load disturbance on the temperature performance and energy efficiency of AC system,the dynamics of the refrigeration cycle and cabin heat load was modeled based on the moving-boundary and lumped parameter method in this paper,and the heat load information was incorporated into the control model of AC system. Then,adopting the Markov chain algorithm to predict the disturbance of heat load,a stochastic model predictive control algorithm was proposed. The simulation results show that the proposed algorithm can improve the temperature performance and energy efficiency of the AC system.

Analysis of the Friction and Wear of the Barrel Bore During the Continuous Engraving Process

ZOU Libo, YU Cungui, FENG Guangbin, ZHONG Jianlin, LIU Xianfu

2021, 41(5): 487-493. doi:10.15918/j.tbit1001-0645.2020.081

Abstract(727) PDF(342)

Abstract:
During the firing of the artillery, under the high temperature and high pressure environment, the interaction between the rotating band and the barrel can cause the structural size change of the forcing cone which directly affects the ballistic performance of the gun and the life of the barrel. In order to study the friction and wear laws of the forcing cone during the continuous engraving process, a refined finite element mesh model of the forcing cone structure was established. Based on the projectile-barrel coupling thermodynamic finite element model, the effects of the temperature and pressure of gunpowder gas, the friction coefficient between the rotating band and the forcing cone were comprehensively considered, and combined with the Archard wear model, the numerical calculation method was used to obtain the forcing law of the forcing cone and the amount of wear due to friction under the continuous shooting environment. Analysis results indicate that, the developed refined finite element mesh model of the forcing cone structure possesses an evident effect in expressing the friction and wear of the forcing cone, the structure of rotating band affects the forcing law and the amount of the forcing cone evidently, there is a serious force and wear in the transition part of rifle forepart positive thread under single or continuous shots.

Research on Vibration Reduction Technology of High-Precision Plane Grating Scale Measurement System

YUAN Zhiyang, ZHU Yu, CHENG Rong, ZHANG Ming, LIU Jian, ZHONG Kai

2021, 41(5): 494-500. doi:10.15918/j.tbit1001-0645.2020.084

Abstract(655) PDF(269)

Abstract:
High-precision plane grating scale measurement system (PSMS) is the core measurement system of immersion scanner.Its measurement accuracy directly affects the positioning accuracy and settling time of wafer stage in immersion scanner.The plane grating scale (PS) is mounted on the plane grating scale carrier (PSC).Due to the low natural frequency of PSC,it is easy to be vibrated by the residual vibration of the main plate and the pressure disturbance of the high-speed wafer stage,so it is of great significance to study the vibration damping technology of PSC.In this paper,a new type of PSC vibration damping method was introduced,focusing on thermal decoupling technology and viscous damping vibration absorption technology.With the use of theoretical modeling,simulation analysis and test evaluation,the results show that the parallel system of viscous damper and flexible structure can significantly improve the dynamic characteristics of PSC structure,improve the measurement accuracy of plane grating scale measurement system and shorten the settling time of wafer stage.

Silicon Based MEMS Safety & Arming Device Design for Small-Caliber Ammunition

SUN Yi, LOU Wenzhong, FENG Hengzhen, ZHENG Xuejun

2021, 41(5): 501-506. doi:10.15918/j.tbit1001-0645.2020.057

Abstract(671) PDF(277)

Abstract:
A miniaturized intelligent MEMS Safety & Arming device system was designed for small caliber ammunition, being capable of launch environment identification. Firstly, a model of silicon-based MEMS Safety & Arming device system was established based on the ballistic environment of self-balancing launch system for small-caliber ammunition. And considering the launch environment and service processing environment, a threshold-value judging mechanism model was designed for the MEMS Safety & Arming device system. Secondly, the structure design and optimization were carried out by the means of theoretical calculation and dynamic simulation. Thirdly, according to the MEMS processing technology, the device was manufactured. Finally, the performance test of MEMS Safety & Arming device system was completed through ground simulation test, so as to meet the requirements of small caliber ammunition for safety system quantification and high reliability service.

Accurate Inversion of Aerosol Backscattering Coefficient in the Near-Ground Haze Condition with Rotational Raman-Mie Lidar

ZHANG Yinchao, HE Jingxi, CHEN Siying, GUO Pan, CHEN He

2021, 41(5): 507-512. doi:10.15918/j.tbit1001-0645.2020.067

Abstract(620) PDF(228)

Abstract:
A modified inversion method for aerosol backscattering coefficient in the near-ground haze condition was proposed for rotational Raman-Mie lidar.In order to solve the problems of the intensity of the elastic scattering light to exceed the generally applicable suppression ratio of lidar system resulted from the surge of aerosol concentration in the near-ground haze condition,and some distortions of the Raman signals caused in the leaked elastic signal,a correction method was proposed to modify the abnormal signal with coefficient and considering the effect of atmospheric temperature on the aerosol backscatter inversion in addition.Experiment results show that,compared with the classic Raman-Mie method,the proposed method can improve the accuracy of the aerosol backscattering coefficient in the near-ground stable aerosol layer by about 20% so as to enhance the detecting performance of Raman-Mie lidar in polluted air condition.

Synthesis of 3,4-Disubstituted 1,2,3,4-Tetrahydroquinoline Thiocyanates Based on Thiocyanation-Cyclization ofN-Cinnamyl Sulfonamides

CHEN Fuxue, YUAN Lexia, QIU Jiashen, WU Di, YIN Hongquan

2021, 41(5): 513-521. doi:10.15918/j.tbit1001-0645.2020.058

Abstract(846) PDF(359)

Abstract:
Compounds containing other important functional groups can be synthesized by the functionalization conversion reactions of olefins, such as halogenated compounds, sulfur trifluoromethyl compounds and selenophenyl compounds.It is difficult to synthesize thiocyanates based on the formation of new C-C bonds from olefins.In this study, a thiocyanation-cyclization method ofN-cinnamyl sulfonamides was developed to prepare 3,4-disubstituted 1,2,3,4-tetrahydroquinoline thiocyanates by constructing a new C-C bond in hexafluoroisopropanol (HFIP) with zinc chloride existence.The reaction conditions were mildly arranged with high yield and high regio-selectivity,and a new free radical mechanism was proposed based on the newly discovered cationic thiocyano reagent (N-thiocyanosaccharin).

Synthesis of Metal-Organic Cages and Their Applications in Chromatographic Separation and Selective Adsorption

LUO Aiqin, SUN Chenyu, TANG Bo, HOU Huipeng, SUN Liquan

2021, 41(5): 522-530. doi:10.15918/j.tbit1001-0645.2020.047

Abstract(731) PDF(293)

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As a new type of porous material,metal organic cages (MOCs) possess the characteristics of adjustable geometry,diverse cavity structures,and easy modification.At present, there are many applications in the fields of sensing,catalysis,and molecular recognition.The applications of selective adsorption and chromatographic separation have also attracted great interest from researchers.In this article,the progress of the synthesis of MOCs and their applications were summarized in selective adsorption and chromatographic separation areas in recent years,presenting the prospects of their development.

Orthogonal Search Method for Geomagnetic Matching Based on Inertial Navigation Error Characteristics

HAN Yongqiang, ZHANG Yanshun, CHEN Jiabin

2021, 41(5): 531-535. doi:10.15918/j.tbit1001-0645.2020.045

Abstract(544) PDF(249)

Abstract:
Aiming at the real-time requirement of geomagnetic matching navigation,an orthogonal search method based on inertial error characteristics was proposed.Based on the analysis of inertial navigation error characteristics,this method was arranged to adopt an orthogonal search strategy to perform orthogonal search on the geomagnetic data sequence of the matching point after interpolation along the vertical direction and the parallel direction of the flight trajectory respectively,to quickly obtain the best matching result.Extending the geomagnetic data of the ground measurement to different heights,the proposed method and the global search algorithm were used to process geomagnetic data.The data processing results show that the method in this paper has the same matching accuracy as the global search algorithm,but it can reduce the search time and can effectively improve the real-time performance of the matching and positioning method of high-speed high-altitude aircraft.

Design and Implementation of Two-Dimensional Bidirectional CFAR Processor Based on FPGA

GAO Wei, XIE Fang, JIANG Rongkun, YANG Hao, WANG Xiaohua, LÜ Yuqing

2021, 41(5): 536-541. doi:10.15918/j.tbit1001-0645.2020.002

Abstract(837) PDF(303)

Abstract:
In radar adaptive detection, one-dimensional CFAR processor can only perform target detection in a single dimension.Based on the one-dimensional CFAR algorithm, a new method was proposed to implement a two-dimensional bidirectional CFAR processor structure on FPGA.Considering the detection information of the distance dimension and the Doppler dimension synchronously,the structure was arranged to improve the detection accuracy.The processor was designed for six algorithm options,supporting CA,GO,SO,OSCA,OSGO,and OSSO CFAR detectors,and also supporting configurable number of reference cells,number of protection cells,ranking values,and threshold factors to be applied in a variety of clutter environments.Experimental results show that,when the signal-to-noise ratio is 12 dB,the detection probability of the six detectors can reach above 80%.The maximum integrated clock frequency of this processor is 137 MHz,and the logic unit used is much smaller than the FPGA resources,which can meet the requirements of practical engineering applications.

A t-Test Method for Detecting Power Information Leakage of S-Box

YAN Yingjian, ZHENG Zhen, GUO Pengfei, ZHU Chunsheng

2021, 41(5): 542-547. doi:10.15918/j.tbit1001-0645.2020.001

Abstract(598) PDF(261)

Abstract:
In order to improve the efficiency of t-test in the leakage detection of Block Cipher power information, a new t-test method was proposed.Firstly, the basic steps of t-test to detect power information leakage were introduced.The nonlinear property of S-box was studied by Walsh spectrum.The concept of transparent order was introduced and its relation with nonlinearity was deduced.And the relationship between the nonlinearity of the output bits of the S-box and the leakage of power information was further established.And then, a method was proposed to determine the order of performing t-test on the output bits of the S-box, so as to the sequential detection carried out according to the nonlinearity of the output bits of the S-box.Finally, the first round S-box of DES encryption algorithm was used as an example for verification.The results show that the proposed method can effectively improve the detection efficiency of power information leakage by t-test.

Human-Computer Interaction System Based on Planar-Aid for Head-Mounted Virtual Reality Environment

CAO Li, WU Xiaowei, LI Lin

2021, 41(5): 548-557. doi:10.15918/j.tbit1001-0645.2019.307

Abstract(604) PDF(312)

Abstract:
Aiming at the problem of natural and efficient interaction in immersive virtual reality environment, a new Human-Computer Interaction Method for Head-mounted Virtual Reality Space was presented. A Planar-aid was used to introduce the paradigm of the smart tablet to the head-mounted virtual reality environment. An efficient interaction system was implemented by tracking the hand and Planar-aid efficiently with single depth camera. For the interaction error caused by the size difference between the virtual and the real interaction plane, an improved haptic retargeting solution was proposed. The solution was arranged to enable the interaction operation to switch between adjacent targets continuously, and also to effectively prevent virtual hand from shaking during switching. Test results show that the method can not only be easy to use, but also can improve the interaction accuracy and interaction efficiency.

A Self-Labeling Feature Matching Algorithm for Instance Recognition on Multi-Sensor Images

ZHANG Xupei, HE Zhanzhuang, MA Zhong, YANG Yidai

2021, 41(5): 558-568. doi:10.15918/j.tbit1001-0645.2020.092

Abstract(895) PDF(341)

Abstract:
Due to the great difference of the images from imaging apparatuses, the existing state-of-the-art algorithms are hard to obtain corresponding features for matching processing or the instance recognition on multi-sensor images (such as RGB and infrared images). To solve this problem, a new feature matching algorithm was proposed based on a self-labeling technique, being able deep learning and extracting feature. Firstly, an immature detector was designed and trained with synthetic images to be competent for feature extraction on different types of images. Then, a self-labeling method was proposed to obtain the corresponding feature points on the multi sensors images, and the self-labeling results were used for detector and descriptor training to achieving the instance recognition on multi-sensor images based on the matching feature points. Finally, hundreds of pairs RGB and Infrared images were collected from different scenarios and condition, and some experiments were carried out to compare the proposed algorithm with 6 different state-of-the-art algorithms. The experiment results show that the proposed algorithm can provide much and accurate corresponding feature points than other state-of-the-art algorithms, improving the average precision significantly.

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2021 Vol. 41, No. 5

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