Table of Content

30 September 2002, Volume 23 Issue 3

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Paper

Dynamic Analysis of Mobile Weapon Systems with Clearances: PartII Clearance Joint Models

1:Li Haiyang;2:Wu Delong,Zhang Yong

2002, 23(3):  289-293.  doi:10.3969/j.issn.1000-1093.2002.03.001

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Based on the vectorial frictional impact model introduced in part I，models of revolution clear?ance joint and sliding ring clearance joint are built up respectively. In the models, motion states in clearance are described in a unified form. The influences of the clearance joint are decomposed into two parts, namely geometric constraint and nonlinear elastic connection, which are described by constraint equations and rela?tive aisplacement-force relationships respectively. Contact states need not to be judged in this model. So it is convenient for the analysis of complex systems. Furthermore, the models are derived in three-dimensional space, and can be simplified in two-dimensional problems.

Finite Element Analysis on the Dynamic Characteristics of High Efficiency Diesel

Feng Huihua, Zuo Zhengxing, Liao Ridong,Zhang Yushen

2002, 23(3):  294-298.  doi:10.3969/j.issn.1000-1093.2002.03.002

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Basea on the convergence analysis of discrete errors on the basis of comparison with experi?ment, a V6 diesel engine’s finite element models oi its chief components and assembly have been estab-lished. Adopting the Lanczos method, their free-free modal computations have been conducted. Evaluations have been made on the dynamic characteristics of the modified scheme，and conclusions drawn from the analysis have been successfully adopted in the redesign of the diesel’s structures.

An Investigative Exploration of a Fuzzy Expert System on the Fault Forecasting for a Self-Propelled Gun

Huang Jingde, Wang Xinggui,Wang Zuguang

2002, 23(3):  299-303.  doi:10.3969/j.issn.1000-1093.2002.03.003

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A fuzzy expert system on the fault forecasting for a self-propelled gun is developed using an object-oriented approach. This paper introduces the overall frame and the functions of every functional mod?el in the system. The method of realization of fault forecasting and system alarming, as well as the approacn of inference are illustrated.

A Study on the Compilation of Firing Tables for Gatling Guns

1:Han Zipeng, Wang Zhongyuan;2:Shu Yanchun

2002, 23(3):  304-307.  doi:10.3969/j.issn.1000-1093.2002.03.004

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This paper discusses the characteristics and corresponding compilation of firing tables for Gatling type of guns. Making use of theoretical analysis and firing tests, the paper studies the influence of turning of the tubes and the metod of correction under various rates of turning. Firing tests have proved that the introduced method is sound and suitable for application and the compiled firing tables are shown to be of sufficient accuracy.

A New Optimization Design for the Aerodynamics and Terminal Ballistics of Explosively Formed Penetration (EFP)

1:Lu Yonggang;2: Jiang Jianwei,Men Jianbing

2002, 23(3):  308-312.  doi:10.3969/j.issn.1000-1093.2002.03.005

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Based on a comprehensive study of the effect of flared EFP shape parameters on the aerody?namic performance and terminal ballistics, a new optimized design that is engineering-achievable at present is presented, in order to reduce flight drag and improve flight stability, and thus to increase the depth of penetration of the EFP. In this design, a spike is added to the nose of the EFP according to the aerodynam?ic principle of rod penetrator, to improve its aerodynamics performance while keeping an optimized simple flared rear. A analysis shows that penetration performance of the optimized EFP is significantly improved.

Interference of Close to Ground Air Currents on Acoustic Fuze

Li Ping, Bai Yuxian,Cui Zhanzhong

2002, 23(3):  313-315.  doi:10.3969/j.issn.1000-1093.2002.03.006

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Based on theoretical analysis and experimental tests, the characteristics of close to ground air currents and their interference on acoustic fuzes are studied. Research figures about their influence on acous?tic fuzes at various heights are analyzed and differences in acoustic signals from targets under diverse wind conditions are compared.

A Study on Crystalline Characteristics of Expanded Ammonium Nitrate

Lü Chunxu

2002, 23(3):  316-319.  doi:10.3969/j.issn.1000-1093.2002.03.007

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Expanded ammonium nitrate (AiN) is a kind of new improved AN, possessing outstanding self-sensitized characteristics, and is successfully applied to various kinds of expanded AN explosives and seismic explosive columns. Under the action of expanding agents (surfactants), its physical properties, crystalline structures and characteristics are remarkably improved. In tms paper, through determination of solid surface contact angles, the surface energy of expanded AN crystal is calculated. Influence of expanding agents on crystalline cnange is obtained through DSC，and the crystal lattice characteristics of expanded AN are analyzed through SEM.

Prediction of Peak Particle Ground Vibration of Near Source Cylinder Charge

Xu Quanjun， Wang Xizhi， Ji Maorong,Long Yuan,Shen Wei

2002, 23(3):  320-323.  doi:10.3969/j.issn.1000-1093.2002.03.008

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On the basis of projects engineering the method of Laplace transformation and enclosed inte?gral is applied to solve problems of stress wave field excited by coupled cylinder charges. The role of laws of attenuation for the peak particle displacement of a single near source is achieved. Results of calculation meet well those of measured experimental data. Furthermore the prediction of peak particle ground vibration of near source cylinder charges is realized.

Ground Clutter Models and Simulation for Two Types of Airborne Radars

Su Weimin, Sun Hongbo,Gu Hong,Liu Guosui

2002, 23(3):  324-328.  doi:10.3969/j.issn.1000-1093.2002.03.009

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Discusses the ground clutter model and simulation for airborne radars. Doppler and scattering characteristics of ground clutter for airborne radars are analyzed. Based on the clutter model proposed by Klemm R, ground clutter energy distribution are then discussed using space-time two dimensional spectrum according to different features of airborne early warning radar and synthetic aperture radar respectively. Two ground clutter models and simulation methods are presented on different conditions. The two models presented are simple and practicable. Radar data collected by the MountainTop Project USA and an air?borne experimental radar are used to testify the above two models. Comparison of results has proved their applicability.

A Model Based on Texture Analysis for the Performance Evaluation of Camouflage Screen Equipment

:1：Xu Weidong；2：Lü Xuliang,Chen Bing；3：Xue Shiqiang

2002, 23(3):  329-331.  doi:10.3969/j.issn.1000-1093.2002.03.010

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Basic principles of texture analysis in digital imaging are made use of and signatures of sur?rounding background simulation are studied for camouflage equipment such as screens. A model is there by developed to evaluate the performance of camouflage equipment quantitatively. Compared with the discov?ery probability model mtherto in use the study showed that this model possesses advantages such as high de- terminability and operability.

A Study on Laser Echo Rate Based on Satisfaction Estimation

Cheng Xiangquan, Guo Zhi, Wang Yuangang ,Yu Hai

2002, 23(3):  332-335.  doi:10.3969/j.issn.1000-1093.2002.03.011

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Based on the satisfaction estimation theory, this paper presents a method that predicts the center of object so that in the whole moving phase of the object, the laser echo rate is used in measuring the distance of object, meeting the prescribed requirements. Linear matrix inequality (LMI) method is adopted to study the satisfaction estimation proolem, and satisfaction filter gain is obtained applying the Matlab— LMI toolbox.

Locating Targets Using Multistation Receiver Systems in Overcoming the Range Ambiguity of Television signals

Guo Qiang, Tao Ran, Wang Yue,Zhou Siyong

2002, 23(3):  336-340.  doi:10.3969/j.issn.1000-1093.2002.03.012

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Poor unambiguous range is considered one of the problems the television-based bistatic radar is faced with. In tnis paper, the mechanism using target-locating to overcome range ambiguity was studied extensively, where it is the sum of transmitter- to- target and target-to- receiver range that is measured and a kind of optimal method was proposed to determine the maximum unambiguous and measurable ellipsoid ac?cording to the extreme operating range of the transmitter. The relation between the baseline and maximal unamDiguous and measurable airspace was pointed out. This will offer an effective approach for utilizing ful?ly the power of the transmitter and selecting the maximum unambiguous and measurable airspace.

A Reflection Laser-Scanned Inspection System

Xu Xiping, Zhang Guoyu, An Zhiyong,Li Chengzhi

2002, 23(3):  341-343.  doi:10.3969/j.issn.1000-1093.2002.03.013

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Based on the laser-scanned inspection principle and the optoelectronic transformation technolo?gy ，a new method of inspection is proposed which can be used to measure larger diameters of work-piece by reflected laser-scanned inspection. A parabolic reflector is used as the scanning optical system. The working principle,overall structure and the real-time data processing system are briefly described. The measuring precision of the system is verified by experiment to be ±0. 01mm，as shown by the measured results.

Numerical simulation of Three Dimensional Hypersonic Complicated Flowfield with a Cross Jet

Li Hua ,Wang Chengyao

2002, 23(3):  344-346.  doi:10.3969/j.issn.1000-1093.2002.03.014

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Time-dependent numerical method is used to solve the three dimensional Navier-Stokes equa?tions. In the numerical procedure, Chakravarthy-Osher TVD scheme is used for the convective terms and central difference scheme for viscous terms, and the Baldwin-Lomax turbulence model is used. Numerical solution of the hypersonic flow over a blunt conic body with cross jet at 5° attack angle was obtained. The numerical results of pressure were compared with the experimental data. And the multigrid method is also used to accelerate the convergence.

A New Type of Combined Terminal Guidance Law

1:Zhang Hexin, Xu Hualong;2:Xu Jie

2002, 23(3):  347-350.  doi:10.3969/j.issn.1000-1093.2002.03.015

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Proportional navigation guidance (PNG) embodies in itself several shortcomings, namely its low precision of control, requiring high overload acceleration,and vulnerability to noise. A new approach of simple combined navigation guidance (CNG) law is proposed, utilizing PNG in conjunction with pursuing navigation guidance. The advantage of this guidance law lies in its easy implementation, requiring low over?load acceleration. A number of simulations are given in the article. The results show that requirements to missile overload acceleration with the combined terminal guidance law is less than that with tne PNG, and the missdistance can be reduced markedly.

A Study on the shock Wave in a Conical Laval Nozzle

Tao Gang

2002, 23(3):  351-354.  doi:10.3969/j.issn.1000-1093.2002.03.016

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Studies the shock wave in a conical Laval nozzle using V. N Uskov’s method of differential dynamics compatibility condition，in wmch the nozzle pressure ratio n is equal to I. Through mathematical analysis, analytical solution of forming suspending shock wave is obtained for these conical LavaI nozzles. The calculated results are shown in figures for different nozzles, one of which is compared with the results obtained from the characteristic method.

Influence of Rotational Speed Adjustment Board on the Rotational Speed in Flight

Guan Weiqun,Zhang Jing

2002, 23(3):  355-357.  doi:10.3969/j.issn.1000-1093.2002.03.017

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The influence of rotational speed adjustment board on the rotational speed in flight is studied. The aerodynamic characteristic is first calculated with the rotational speed adjustment boards on or off, and in circumstances when the features of the boards are changed. Then the rotational speed is simulated. The simulation results show that the rotational speed adjustment boards remarkably affect the angular moment and the rotational speed in flight and that changing features of the rotational speed adjustment board can modify the extent of the effect on the rotational speed.

Neural Network Control and Guidance for Agile Missiles

Dong Chaoyang, Jing Shaoguang, Wang Qing,Zhang Minglian

2002, 23(3):  358-361.  doi:10.3969/j.issn.1000-1093.2002.03.018

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Advanced agile missiles possess maneuverability, agility and precise guidance performance by adopting thruster vector control. System dynamics and modelling for the advanced missiles with thrust vec?toring is investigated, and neural network control and guidance for advanced missiles is proposed. Two neu?ral network control methods are presented ： the twin dynamic inversion networks learning control and the integrated neural network control. The neural network guidance uses the teacher learning method according to the linear-quadratic optimal guidance law. Fuzzy learning rules are introduced to improve the learning a- bility of the neural network system. Numerical simulation results show that the proposed neural network control and guidance has good performance to hit maneuvering targets.

Design of Autopilot on a Missile with a General Adaptive Control Structure

1:Wang ZhengJie, Zhang Tianqiao;2:Li Jinong

2002, 23(3):  362-365.  doi:10.3969/j.issn.1000-1093.2002.03.019

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Design of the missile autopilot is a key in making the missile to possess high hit precision. A general adaptive control structure is applied in designing the missile autopilot. A damping inner-loop and an accelerating outer-loop of the pitch channel for the missile autopilot are designed by an adaptive generalized predictive control (AGPC) algorithm to make the missile offer relevant acceleration rapidly according to in?structions for guidance. It is proved from the results of system math simulation carried out under some typi?cal conditions, that the designed control algorithm can control the missile to attack the target satisfying the tactical requests. Furthermore, it is restrained from some uncertain disturbances such as un-model dynam?ics, aerodynamics parameters dispersions and noise.

Shock Wave Interaction with a Bottom Wall Covered by a Material Layer

1:Fan Baochun;2:Li Jie,Ren Bing

2002, 23(3):  366-369.  doi:10.3969/j.issn.1000-1093.2002.03.020

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Density Function of the Time for Target Killing Involving the Target Detection Time

Liu Liwei

2002, 23(3):  370-373.  doi:10.3969/j.issn.1000-1093.2002.03.021

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This paper considers the famous model for elementary stochastic duels put forward by Williams I and Ancker Cj Jr in reference 1. For the given model it is a requisite first to deduce the probability den?sity function of the time needed to kill a target under the condition that one side involved in the duel is a passive target. But the factor concerning the time required to detect the target is not considered in deducing the density function，thus a more practical model would be to alter it so as to search for the target first. The paper considers this factor and deduces the density function of the time needed for killing the target and the winning probability. Several cases are calculated，considering the conclusions induced in reference 1 as a special case.

A Fault Diagnosis for Spacecrafts Based on Fuzzy Pattern Recognition

Rong Jili

2002, 23(3):  374-376.  doi:10.3969/j.issn.1000-1093.2002.03.022

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In accordance with the condition of recognition and fault diagnosis for spacecrafts, the con?cepts of symptom vector and relevant fuzzy symptom vector is presented. A fuzzy pattern recognition ap?proach of fault diagnosis for spacecrafts is suggested. In comparison with the result from an expert system the method is verified and validated, making use of three fault examples in a testbed.

Highly Efficient Ways in Machining a Sophisticated Surface on a 5-Axis NC Machine Tool

1:He Zhaotai;2:Liu Huran ,Li Guoshun ;3:Xiong Guoliang

2002, 23(3):  377-379.  doi:10.3969/j.issn.1000-1093.2002.03.023

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An innovative theory for machining complicated surfaces is presented. By a cylindrical milling cutter instead of a ball-end miller, and adjusting the axis relative to the surface, the formed surface can at?tain the same curvature as the requisite surface, up to as high as the third order.

A Study on the Reversal of Roll-Forming Molds Based on Fuzzy Theory and Its Applications

Wang Ailing ,Wang Junyuan,Zhang Jitang

2002, 23(3):  380-383.  doi:10.3969/j.issn.1000-1093.2002.03.024

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Reversal of production systems is presented, and a study on the reversal of production line based on fuzzy theory is put forward, enabling a defective production line to go on properly through the re?newal of key parts. This technology has been used to the reversal of imported production lines for roll- moulding of complicated shapes. Two new production lines have been designed on this basis, getting abun?dant economic profits.

Short Papers

Case-Based Reasoning Method and Its Application in Determining the Index System of a Fire Control System

Hu Shaoyong,Zheng Yingping

2002, 23(3):  384-387.  doi:10.3969/j.issn.1000-1093.2002.03.025

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It is an extremely complicated yet important work in determining the index system of a fire control system. It is also the prerequisite condition in laying down the total scheme. Case-based reasoning method is proposed in defining the index system of a fire control system according to its types and character?istics. Some critical techniques are analyzed so that the case-based reasoning method can be applied to the overall design of the fire control system. The application is realized using computer cooperation supporting tools.

Comprehensive Reviews

A Review on the Oxidation Degradation of Organic Pollutants in Wastewater by Ultrasound in the Presence of Ultraviolet Irradiation

He Qihuan ,Ye Zhaolian

2002, 23(3):  388-391.  doi:10.3969/j.issn.1000-1093.2002.03.026

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The technique of degradation of organic pollutants by ultrasound is described, including its principle, effect and development at home and abroad. The interaction mechanism is Dased on the cavita?tion .Ultrasound technology,combined with ultraviolet irradiation, catalysis and oxidation, can greatly in?crease the degree of mineralization organic pollutants. The procedure has eminent prospects in the degrada?tion of unbiodegradable，toxic and hazardous organic pollutants，especially on those of environmental priori? ty.

Experimental Techniques and Analysis

Industrial Measurement System Based on an Electronic Theodolite and Precision Analysis

Wang Jinjtang, Di Xu, Jin Sukun, Yang ZhiWen

2002, 23(3):  392-394.  doi:10.3969/j.issn.1000-1093.2002.03.027

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Principle of the industrial system measurement using a tneodolite as the sensor is introduced, with sources of error and their effects upon precision analyzed. Theoretical analysis and measurements on a standard ruler indicate that the relative precision of the system can attain 1O-5. The system is expected to be widely used in the field of large-scale manufacturing and industrial measurements.

Influence of Processing Parameters on the Chemical Composition and Performance of TiN-MoS2/Ti Composite Coatings Deposited by Nano-Composite Plating Technology

1:Jing Yang, Pang Siqin, Zhou Lanying;2:Zhong Shengdong

2002, 23(3):  395-398.  doi:10.3969/j.issn.1000-1093.2002.03.028

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Coatings have been deposited with the nano-composite unbalanced plasma plating technology. Influence of the processing parameters on the tribological and physical-chemical properties of TiN—MoS2/ Ti composite coatings was examined with drilling and turning experiments and XPS. Through the experi?ments ，it was found that changes of parameters such as electrode spacing，deposit pressure and the contents of Ti additives influenced considerably on the chemical composition and performance of the composite films. It indicated that TiN—MoS2/Ti composite coatings with higher abrasion durability can be obtained by ad?justing and choosing appropriate processing parameters.

An Experimental Study of Square-Formed Fences for Reducing the Aerodynamic Drag of a Van Truck

Zhao Lanshui,Kong Xianlei

2002, 23(3):  399-401.  doi:10.3969/j.issn.1000-1093.2002.03.029

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A method of passively controlled boundary-layer is introduced. Square-formed fences mounted on the front face of the bluff body of the truck are used to reduce the pressure on the face against the wind， delay the separation oi the boundary-layer on the front section of the top-face, and improve the state of air flowing arouna the body and decrease the drag resulting from pressure difference. The proposal broadens the way of reducing drag and saving energy.

Research Notes

Steering Control in Remotely Controlled Tracked Vemcles

Wu Shaobin, Ding Huarong, Liu Li ,Chen Huiyan

2002, 23(3):  402-405.  doi:10.3969/j.issn.1000-1093.2002.03.030

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This paper describes the scheme and construction of the steering control system in a remotely controlled tracked vehicle, rield tests have proved that the steering control system can satisfy demands for heading controls in remote driving.

A Study on the Launching Dynamics of Machine Gun System

Yao Jianjun,Xu Cheng

2002, 23(3):  406-408.  doi:10.3969/j.issn.1000-1093.2002.03.031

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A lumped parameter model with 18 parameters is proposed to represent a launcher. On this basis，the finite element system model consisting ot the launcher，machine gun and soil is established and its eigenvalue and response at the muzzle when launching continuously are obtained from calculation. It is well consistent with conclusions from experiments.

A Study on the Method of Testing Fuze Tums-Counting Sensor

Wang Li, Huang Xiaomao, Chen Hejuan,Lai Baitan

2002, 23(3):  409-411.  doi:10.3969/j.issn.1000-1093.2002.03.032

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On the basis of theoretical analysis and computer simulation for turns-counting in fuzes, labo?ratory simulation has been made. In particular, simulations without considering precession were carried out. Test results were found to be in accord with theory. Static tests showed the feasibility of the method and provided test evidence for more practical applications.

Crystal Properties of Modified Ammonium Nitrates

Ye Zhiwen, Lü Chunxu, Liu Zuliang

2002, 23(3):  412-415.  doi:10.3969/j.issn.1000-1093.2002.03.033

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In this paper, some crystal properties of modified ammonium nitrate treated with composite surfactants are analysed by scanning electron microanalyzer，differential scanning calorimetry，X-ray diffrac?tion, and their specific surface area, anti-hygroscopicity,anti-caking as well as explosion properties are ex?amined. The results show that, compared to conventional ammonium nitrate, modified ammonium nitrate crystals possesses disproportionate shape, larger specific surface areas. They contain large numbers of gas- pockets, lowerheat of crystal pattern transition; their temperatures of crystal pattern transition are moved backward, and their crystal lattice structure do not change. The modified ammonium nitrate has better per-formances in anti-hygroscopicity and anti-caking. Powder industrial explosives produced from modified am?monium nitrate have better physical properties as well as those of explosion.

Receiving and Processing System for a Helmet-Mounted Laser Combat Practice simulator

1:Lin Yuanfang;2:Huang

2002, 23(3):  416-417.  doi:10.3969/j.issn.1000-1093.2002.03.034

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Based on the characteristics of the laser viz. its high brightness and high directivity, and the capability of Demg made invisible when necessary, using the AT89C2051 microprocessor as the core of con?trol a helmet mounted simulation combat practice outfit is designed. The transmission, receiving and alarm?ing of laser pulses can be realized. Block diagram and design principles of the laser simulator and its helmet mounted system are given. Some key items in the design are also discussed.

Gas Sensors in Target Detection

1:Zhang Anmin,Yang Shixing,Li Zhishun;2:Wang Hua

2002, 23(3):  418-421.  doi:10.3969/j.issn.1000-1093.2002.03.035

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Dispersion models of vehicle exhaust, taken as the gas sensor stimulus, are studied with the theory of onflow. Expressions of exhaust denseness are put forward under many battlefield conditions. Through investigation systems of target detection，the paper selects and demarcates the type of gas sensor appropriate for use. Input-output of the gas sensor is studied with regression analysis. The technique of tar?get detection is studied and the basic scheme of detection is given. Target detection probability is obtained through computer random simulation under limited simulation conditions.

VLSI Design of Reed Solomon Decoders

Fang Li, Lü Xin, Deng Ciping

2002, 23(3):  422-425.  doi:10.3969/j.issn.1000-1093.2002.03.036

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This paper focused on the VLSI design and optimal method of the Reed Solomon (RS) de?coder. The first part of the paper includes the RS decoder working theory, and introduces how to convert the computer-based algorithm to the hardware parallel architecture and its optimization. It finally demon?strates the performance of single period hardware RS decoder based on the FPGA which works at IOMHz clock .

Nonlethal Infrasonic Weapon for on-Site Control

Xiao Feng

2002, 23(3):  426-429.  doi:10.3969/j.issn.1000-1093.2002.03.037

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According to the characteristics of infrasonic sound effect on human body, the principle of nonlethal infrasonic weapon for on-site control is put forward. It makes use oi invert piezoelectricity of PZT as the infrasonic unit，and is made up into an M X N infrasonic unit array，attaining a high sound pressure level. On the basis of principle of interference phase control, infrasonic sound is again forced to have con?verged directioned propagation. Thus the two key problems of infrasonic weapon is solved, and a control?lable nonlethal weapon becomes possible. The infrasonic weapon can control infrasonic sound intensity and be put on-off on-site. It is not polluting and can be used concealed.

High Power Array Semiconductor Laser Grown by MBE

Li Zhonghui, Wang Ling, Wang YuXia, Yang Jinhua，Zhang Xingde

2002, 23(3):  430-432.  doi:10.3969/j.issn.1000-1093.2002.03.038

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GaAlAs/GaAs material having gradient refraction index, and a separate confinement single quantum well structure has been grown by MBE. Experimental results show that the sample’s quality reached the design requirements. The CW output power of the array laser diodes is up to 7.2 W with a peaK wavelength of 807nm to 809nm.