Table of Content

31 August 2004, Volume 25 Issue 4

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Paper

Modeling and Dynamic Simulation of Double Side Gearbox Transmission System for Tracked Vehicles

Liu Weiping, Cheng Gang, Wang Hongyan, Wang Liangxi

2004, 25(4):  385-388.  doi:10.3969/j.issn.1000-1093.2004.04.001

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With the trends in the development of tracked vehicle driveline, fowards merging, synthetiza- tion, ana integration of individual members, the conventional tools and means of analysis can no longer sat?isfy the demands of development in modem mechanical, electricical and hydraulic systems and automatic steering control systems. It is an inevitable trend to analyse vehicle performance based on modular models. Based upon modular modeling, a model for the driveline of tracked vehicle is developed. The acceleration performance of the vehicle is simulated and studied. Results of simulation accord well with the results of ex?periment. The model and its method of analysis can be used conveniently to predict vehicular performance.

Adaptive Control for Semi-Active Suspension Tracked Vehicle

1：Guan Jifu, Hou Chaozhen；2：Gu Liang

2004, 25(4):  389-393.  doi:10.3969/j.issn.1000-1093.2004.04.002

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A reduced order model of a quarter vehicle with semi-active suspension is presented, based on an analysis according to the special requirements for suspension in military tracked vehicles. Weighted quadratic performance index related to vertical accerelation and suspension travel is used to design the linear quadratic uaussian (LQG) controller. The LQG control system is then employed as the reference model of a model reference adaptive control(MRAC) system, and the Lyapunov stability theory is used in the design of the MRAG. Simulation results indicate that the MRAC can adapt to the variation of suspension parame?ters and keep the optimality. The proposed system can adapt to the road condintions and variation of sus?pension parameters.

Automatic Shift Control System In Wheeled Armored Vehicles

Chen Zhigang, Zhai Yong, Chen Huiyan

2004, 25(4):  394-397.  doi:10.3969/j.issn.1000-1093.2004.04.003

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Design of automatic shift control system as applied to wheeled armored vehicles is studied. The automatic shift function is implemented by the use of an integrated system involving mechanicsal, elec?tronic, hydraulic and pneumatic elements. Key technology and design methods based on actual drive sys?tems of the vehicle are discussed in some detail. Experimental results showed that the mobility of the vehi?cle has been improved after reconstructing in automatic shift control system. The consumption of the physi?cal strength of the driver is minimized and the working durability enhanced.

Effective Freeboard of Amphibious Vehicles

Xu Guoying, Yao Xinmin, Guo Qisheng

2004, 25(4):  398-401.  doi:10.3969/j.issn.1000-1093.2004.04.004

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Freeboard of a vehicle is an important criterion to an amphibious vehicle, s buoyancy. The concept of effective freeboard is important in the design and use of an amphibious vehicle. A method of its deduction in theory is introduced. Based on the theory of hydrodynamics, the functional relation between vehicle waterline and speed is established. According to the theory of wave movement, parameters of wave caused by speed are determined, and the total variation in freeboard is finally obtained. The paper gives the results of theoretical analysis and experiments for one type of amphibious vehicle.

Hardware-in-the-Loop Engine Simulation For Electronic Control Units Based on thedSpace System

Li Changwen, Zhang Fuju,n Huang Ying,Zhao Changlu, Sun Yebao, Hao Lijun

2004, 25(4):  402-406.  doi:10.3969/j.issn.1000-1093.2004.04.005

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Modem electronic control units (ECU) for use with engines becomes all the more complicat?ed ，but their cycles of development become shorter. Thus ECU hardware-in-the-loop engine simulation comes to be adopted in their development process. The paper introduces their principle, necessity and basic form，along with software and hardware of the dSPACE system and basic modeling methods and develops a single-cylinder diesel engine model for ECU hardware-in-the-loop engine simulation using the MATLAB/ Simulink; ECU hardware-in-the-loop engine simulation experiments were carried out, showing that it can be a useful tool in the development and measurement of ECU.

A Study on the i^inng Accuracy of Self-Propelled Artillery Systems

Wu Ruiwen, Wang Zhaosheng

2004, 25(4):  407-409.  doi:10.3969/j.issn.1000-1093.2004.04.006

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Errors of firing data, errors of automatic operation & aimming error, and dispersion errors of self-propelled artillery are analyzed in details, based on data of error source, accuracy of firing of a certain self-propelled artillery. Influences on firing data by major factors are then discussed according to the results of calculation. Measures to improve the firing accuracy of self-propelled artillery are finally put forward.

Analytical and Experimental Study on the Stability of Firing Frequency of an Air-Defense Machine Gun

Zhu Yuzhen, Yan Hongmin

2004, 25(4):  410-414.  doi:10.3969/j.issn.1000-1093.2004.04.007

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On the basis of analysis of factors affecting the stability of firing frequency, a dynamic model of the automatic mechanism in a machine gun is established. The paper studies the influence of the coeffi?cient of friction, the recoil spring rigidity and the pressure impulse of the gas chamber upon the firing fre?quency stability. Tests were performed on the influence of the recoil spring rigidity and the pressure impulse of the gas chamber by experiments, and reached at conclusions that gave laws of the coefficient of inction, the recoil spring rigidity and the pressure impulse of gas chamber. Technical proposals are given on improv?ing the firing frequency stability. These results provide a gist on controlling the gun s firing frequency sta?bility.

A Study on the Scanning Motion of Single-Fin Target-Sensitivity-Projectile

1:Shu Jingrong,;2:Zhang Bangchu, Han Zipeng,Wei Jinbiao;2:Liu Changyuan

2004, 25(4):  415-420.  doi:10.3969/j.issn.1000-1093.2004.04.008

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Stable scanning is one of the key items in the study of target-sensitivity projectile (TSP). On the basis of analysis of both the advantages and disadvantages of existing stable scanning techniques, the pa?per puts forward a new way to realize stable scanning using a 'tip-weighted single fin, that is, using a strongly-asymmetric mass and aerodynamic means in analyzing the system’s mechanical situation, and es?tablishes a two-body kinetic model. By discussing the method of eliminating and simpliiymg the restriction of force and moment in this model, the paper develops the standard-form equation set suitable for program?ming in a computer, and programs it. A numerical example shows that this kind of structure can realize sta?ble scanning. So the structure can be used in stable scanning, and the kinetic model can be used in the study of TSP total design and its scanning equipment design.

A Study on the Principle of a New Energy Storage Piezoelectric Power Supply

Li Yingping, Lai Baitan, Chen Hejuan, Huang Xiaomao

2004, 25(4):  421-423.  doi:10.3969/j.issn.1000-1093.2004.04.009

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A precise timing or ranging fuze that can load information at the muzzle, demands that the power supply deposited in the projectile can provide electric energy for the fuze circuit reliably before the projectile passes muzzle. Studies a new energy storage piezoelectric power supply that can be used in a me?chanical electronic fuze, and its mathematical model is established in the energy storing process. Chief pa?rameters affecting the storage of energy in speed and capacity are analyzed. The power supply can be acti?vated instantly. It can provide energy for a low consuming energy circuit in little time and can be used in precise timing or ranging of fuzes.

Automatic Assembly in the Modeling of Geometrical Parameters and Finite Element Analysis in the Design of a Shrapnel

Huang Dewu, Song Jianyu

2004, 25(4):  424-427.  doi:10.3969/j.issn.1000-1093.2004.04.010

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In accordance with the demands of a design, through the modeling of geometrical parameters, automatic design of shrapnel can be performed, and the strength calculation and design of parts finished in FEM? Based on the characteristics of design of the shrapnel, development of the special subroutine in C lan?guage is performed automatically, and the mesh and data file for FEM computation provided. The design of profile and strength analysis of the shrapnel are integrated to guarantee the qualities of design and to in?crease efficieny.

Preparation of Nanometer Ni and Amorphous Ni-B Alloys and their Effects on the Thermal Decomposition Characteristics of Ammonium Perchlorate

Liu Leili, Li Fengsheng, Tan Linghua,Yang Yi, Yin Qiang

2004, 25(4):  428-430.  doi:10.3969/j.issn.1000-1093.2004.04.011

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Nanometer Ni powder and amorphous Ni-B alloy catalysts were prepared by chemical reduc?tion, and their average particle size were around 50nm and 20 nm respectively. Differential thermal analysis results showed that there were only slight effects of Ni powder and amorphous Ni-B alloy on the decomposi?tion of ammonium perchlorate peak at lower temperature, while their effects on the decomposition of AP at higher temperature were rather apparent. It showed that nanometer Ni and Ni-B had good catalytic activity on the thermal decomposition characteristics of AP. The DTA energy release of AP goes up clearly in the presence of Ni powders and Ni-B amorphous alloy.

Linear Frequency Modulation Interference Suppression in Direct Sequence Spread Spectrum Systems

1:Qi Lin;2:Tao Ran,Zhou Siyong,Wang Yue

2004, 25(4):  431-435.  doi:10.3969/j.issn.1000-1093.2004.04.012

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For the suppression of linear frequency modulation interference in a direct sequence spread spectrum system, a direct sequence (DS) spread spectrum receiver with an interference exciser using frac?tional Fourier transform is presented. Based on the fact that the localization performance of a given LFM in?terference varies in different fractional Fourier domains, the detection and parameter estimation of the inter?ference are implemented using the fractional Fourier transform. The interference can be reconstructed and excised adaptively. Performance analyses and simulation results have showed that the proposed method works effectively in a large dynamic range. It is easy in computation and simple in implementation.

An Optimal Construction of Wave-Net and Its Applications

1:Zhang Dengfeng, Lian Shiguo, Wang Zhiquan;2:Hu Shousong

2004, 25(4):  436-440.  doi:10.3969/j.issn.1000-1093.2004.04.013

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An algorithm basea on ortnogonal projection operator was proposed to construct the wave-net with respect to the frames theory of discrete wavelet transforms. Its geometrical rate convergence is demon?strated in the finite Hilbert functional space. The algorithm optimizes the constructional process in view of energy distribution information while remaining the signal’s local characteristics in time-frequency domains. An application on fault detection for a fighter verifies its correctness.

Survivability Evaluation of Tactical Communication Networks Based on Clustering

Ren Xiaotao, Zhao Shenghui, Kuang Jingming

2004, 25(4):  441-445.  doi:10.3969/j.issn.1000-1093.2004.04.014

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A new survivability evaluation measure, viz. the global network survivability based on cluster?ing, was proposed. Conventional measures used in the invulnerability and survivability evaluation of tactical communication networks were first discussed, and shortcomings of these measures were pointed out. A new survivability evaluation measure, viz. the global network survivability based on clustering, which is applica?te to tactical communication networks, was then proposed. Some properties and theorem about this mea?sure were put forward. Simulation of survivability evaluation using this measure to 12 kinds of topological networks was finally accomplished. Comparison between this and the LCF measure was also given. I ne re?sults proved that the design of global network survivability based on clustering was reasonable, and that its computation was rapid. Moreover, it can take into account the invalidation of both nodes and links, while possessing fine physical meanings.

A New Rate Allocation Scheme for Fine Granularity Scalability Video Streaming

1：Dong Haiyan, Lu Hansheng, Li Shengcai, Gao Zhiyun；2：Hou Shanfeng

2004, 25(4):  446-449.  doi:10.3969/j.issn.1000-1093.2004.04.015

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An optimal rate allocation method for fine granularity scalable video streaming based on rate- distortion function was presented. The method maximizes the average PSNR of the whole video sequence or minimizes the overall distortion, subject to the bit rate constraint. To solve this problem, the rate-distortion function of the enhancement layer was first established and the Lagrange multiple method was used to get the optimal solution of the constrained optimization problem. Experimental results show that, compared with the uniform rate allocation method, optimal rate allocation can improve the coding efficiency of fine granularity scalable coding and average PSNR of the whole video sequence can be improved up to 12. 288dB. The optimal rate allocation method can greatly reduce fluctuations between adjacent frames. What is more, the optimal rate allocation method can improve the efficiency of the network bandwidth.

Theoretical Analysis of Flow in the Combustion Chamber of a Solid Fuel Ramjet

Chen Jun, Wu Xiaosong

2004, 25(4):  450-453.  doi:10.3969/j.issn.1000-1093.2004.04.016

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Because of its compact structure, high energy and steady working properties, solid fuel ram?jets (SFRJ) are widely used to enhance the distance, prolong the sustenace and raise the attack velocity for medium or small diameter ammunitions. The paper built up models for the flow principle of combustion for such ramjets, ana developed approaches to the solution of the models. Effects of sudden-expansion ratio, inlet velocity of gas,etc, on the flow properties were discussed.

Simulation of the Ejection and Restoration Process of the Ejection Device with a Blank Cartridge

He Daping, Liao Zhenqiang, Wang Tao ,Wang Hui

2004, 25(4):  454-457.  doi:10.3969/j.issn.1000-1093.2004.04.017

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A model of blank cartridge ejection device was established and the ejection and restoration pro?cesses described. The process beginnng from powder burning to the ejection pistons pushing out the bomb and its moving back was analyzed applying classical interior ballistics and gasdynamics theory. A case of e- jection device was calculated, and the effects of different parameters on the ejection velocity were discussed. This offers a theoretical basis for the optimum design of such a device.

Imaging in Inverse Synthetic Aperture Radar (ISAR) Based on Discrete Matching Fourier Transform

Liu Aifang, Zhu Xiaohua, Lu Jinhui,Liu Zhong

2004, 25(4):  458-461.  doi:10.3969/j.issn.1000-1093.2004.04.018

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Imaging of nonuniformly rotating targets and maneuvering targets are difficult but important in ISAR technique. Traditional range-Doppler (RD) method can hardly achieve the desired imaging quali?ty. In this paper, the radar echo signal model of ISAR was analyzed. A new algorithm based on discrete matching Fourier transform (DMFT) for ISAR imaging was then presented to the signal corresponding to each scatterer of the target in the linear frequency modulation (LFM) signal. Computer simulation was ap?plied to illustrate its performance and the simulation results show its effectiveness.

Basic Theory and Technology in the Active Vibration Isolation of Precision Devices

1:Li Guoping;2:Wei Yanding, Chen ZiChen

2004, 25(4):  462-466.  doi:10.3969/j.issn.1000-1093.2004.04.019

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Sources of environment of the precise excitation calling for the use of precision vibration isola?tion platforms were analyzed，and the 2 basic measures of passive vibration isolation and. active vibration iso?lation compared. Based on the discussion, a conclusion is arrived at that active vibration isolation is effective in the range of ultraiow frequency, while passive vibration isolation have its role in the higher frequency range. For wide applications in active vibration isolation, structures and characteristics of giant magne- tostrictive actuators were given. Test results demonstrate that such actuators have perfect stable-state char?acteristics in their displacement output linearity. Some vibrational active control methods that are generally used in active isolation systems were introduced, and the results of three vibration isolation methods(passive control, PID control and fuzzy-PID) were compared.

A Study on the Sizing of Military Helmets Based on Headform Distribution

Chen Xiao, Zhou Hong, Wang Jian

2004, 25(4):  467-471.  doi:10.3969/j.issn.1000-1093.2004.04.020

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Based on studies of Chinese National Standard head — face dimensions of adults and. the Chi?nese Military Standard 3D head - face Dimensions of male soldiers, distribution of head dimensions of male soldiers was analyzed, and the 3D digital information of the standard headform obtained. An algorithms for the sizing of reference headforms and the covering ratios were put forward. They are proposed as the theo?retical basis for sizing and providing infantry helmets and helmets for other armed services, and to improve their ergonomic performance and working performance.

Computational Method for the Reliability Design of Pin Connections

Zhang Yinlong, Chang Damin, Shen Qing

2004, 25(4):  472-475.  doi:10.3969/j.issn.1000-1093.2004.04.021

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The reliability design of a structural member is a probability design taking into consideration the reliability of the member, and is one of the trends in modem design. Based on the theory of structural reliability design, the paper discussed a utility computational method for the reliability design of pin connec?tion. After analyzing the loading and failure modes of the pin and lug plate under different conditions of pin connection such as sustaining shear, extrusion and bending etc.，the paper gave corresponding rules of the reliability design. Then computational formulas and steps for the reliability design of the pin connection were worked out and feasible and useful computational methods were provided on the reliability design of the pin connection.

Short Papers

Fast Computed Tomography Reconstruction with Look-up Table and Polar Coordinate Back-Projection

Yang Min, Lu Hongnian, Huang Chaozhi

2004, 25(4):  476-479.  doi:10.3969/j.issn.1000-1093.2004.04.022

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In order to realize CT fast reconstruction on an ordinary PC, a fast reconstruction process us?ing look-up table and polar coordinate back-projection was presented. Fast back-projection is first executed with the look-up table in polar coordinates. Reconstruction of the image in Cartesian coordinates is then car?ried out when the look-up table is used again to realize the fast interpolation. Computer simulation proved that the method could speed up image reconstruction effectively and the quality ot the image was close to the result of conventional back projection (CBP). When the size of the image is not large, the process can well replace the conventional means.

Comprehensive Reviews

Trends of Development in the Application of Information Science/Technology and Reduction of Weight in Armoured Vehicles and the Development of Anti-Tank Weapons

Song Zhengduo, Shi Xin, Sun Tao

2004, 25(4):  480-484.  doi:10.3969/j.issn.1000-1093.2004.04.023

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The development of armored combat vehicles is currently facing its key transitional phases. These vehicles are represented by new generation main battle tanks and wheeled armored vehicles. Out- sanding features in the development of fighting vehicles are the reduction in weight and application of infor?mation science/technology. The article tries to discuss these trends in their present day development and analyses their future characteristics regarding communication, defence, firepower and mobility. It givens an analysis on the demands of antitank weapon’s firepower assignment, the ability of precision bombing, tar?get damage, communication, mobility, as adapted to the armored combat vehicles. These features will ob?viously promote the operational capability of information assessment and processing，information application and precise attack on air targets. At the same time, it also increases the firepower mobility and integrated defense ability . In order to meet the challenge of antitank weaponry，new tank firepower systems of muiti- guidence, multi attack, and multi damage modes are developed. It is also vital that capabilities of night tar-get identification, mobile land target survilliance, combat command and control and precision of attack should be strengthened. Along with these, terminal guidance ammunition of long range antitank weapon, light ammunition of middle range antitank weaponportable guidance rocket as short range antitank weapon should also be paid due attention.

Accelerated Life Testing： an Introductory Review

Zhang Chunhua, Wen Xisen, Chen Xun

2004, 25(4):  485-490.  doi:10.3969/j.issn.1000-1093.2004.04.024

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Accelerated life testing (ALT) is an important branch in reliability testing and is a focus of re?search both for statisticians and reliability engineers. The paper outlines the four topics of study embodied in ALT, viz. ： statistical analysis for constant-stress testing, step-stress testing and progressive stress testing, and optimal design for ALT. It gives a general review of engineering applications of ALT in China, and points out some possible directions in ALT, giving some suggestions for further study.

Experimental Techniques and Analysis

A Testing System for the Parameters of Crankshaft Torsional Vibration Dampers

Liu Xinghna, Qiu Tao, Liu Fushui, Li Jianchun

2004, 25(4):  491-493.  doi:10.3969/j.issn.1000-1093.2004.04.025

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Torsional vibration dampers for crankshafts are widely used in internal combustion engines. Characteristics of the dampers affect greatly engine’s performance, yet there is a lack in testing devices for damper characteristics. An automatic testing system for the parameters of torsional vibration dampers on engine crankshafts is presented. Based on the sinusoidal scanning, a process of ‘‘testing-data analysis-test report” is automatically achieved. Compared with the B&K testing system, the new system can provide the characteristic parameters of crankshaft torsional vibration damper more accurately.

A Study on the Effects of Storage Environment upon the Hydrogen Content in Lean UraniumAlloys

Yu Shuhua, Wen Bangwei, Yang Xiaoran

2004, 25(4):  494-497.  doi:10.3969/j.issn.1000-1093.2004.04.026

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Micro amount of hydrogen in uranium has significant effects on the mechanical property of u- ranium alloys. The purpose of this article is for a further study on the effect of micro amount of hydrogen content upon the mechanical property of lean uranium alloys. Alloys after three different surface treatments were tested in seashore and inland environments, and given packaged storage, indoor exposure, low mois?ture storage and outdoor exposure.丄 ne change of hydrogen content during exposure was studied. It was proved that the main environmental factors causing the hydrogen content to increase were the chloride ion, sulphur dioxide and water vapor. Different kinds of surface treatment have significant effects on the hydro-gen content of alloys and the hydrogen picked up was in the surface layer of I?2mm depth. The hydrogen content has little change in a dry environment, nydrogen in plated uranium has a tendency of diffusion to the outside.

A Study on the Experimental Simulation for Bursting of the Charge Bed

1:Rui Xiaoting,Wang Hao,Huang Ming,Chen Jianzhong,Chen Tao lau Jun; 2:Yun Laifen

2004, 25(4):  498-502.  doi:10.3969/j.issn.1000-1093.2004.04.027

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Simulation of the compression and bursting of the charge bed in the chamber is one of the key problems in the study of launching safety of gun propellant charge. In this paper, a new kind of experimen?tal equipment that can be used in the simulation is given. Its structure ana working principles are is intro?duced. Lising the semi-closed vessel as the source of compression force, the device can simulate any Kind of dynamic environment in a gun propellant charge. Using the low temperature inert gas (N2）as the compres?sion medium, tlie device can not only ensure that the simulation is real, but also protect the fragmentized propellant is not in combustion after experiment. Using the device, many simulation experiments have been accomplished, and dynamic environment of propellant fracture is acquired. With the experiments, fragmen?tized propellant for the compression and bursting of charge bed is obtained. Results of experiments show that the new device can be of use to study the principle of the compression and bursting of charge bed.

Research Notes

Synthesis of Polyethylene Polyammonium Polynitrates and Characterization of Their Thermostabilities

1:Dai Rongji,Ju Hengyu,Gu Junling,Zhang Ziqing;2:Yang Rongjie,Tong Bin

2004, 25(4):  503-505.  doi:10.3969/j.issn.1000-1093.2004.04.028

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Five kinds of polyethylene polyammonium polynitrates，such as ethylene diammonium dini?trates (DAN)，diethylene triammonium trinitrates ( TrAN)，triethylene tetrammonium tetranitrates (TeAN) , tetraethylene pentammonium pentanitrates (PeAN) and polyethylene polyammonium polyni- trates (PoAN)， were synthesizea in methanol by the reaction of acid and basic components. Their struc?tures were determined by FTIR，elemental analysis and the content analysis of the nitrates. Their ther?mostabilities were studied using DTA and TGA. The results from DTA and TGA showed that these five kinds of polyethylene polyammonium polynitrates had different thermostabilities. DAN started to decom?pose at 185℃，and was totally decomposed at 541℃ ; TrAN started to decompose at 201℃，and was totally- decomposed at 572℃; TeAN started, to decompose at 165℃，and was totally decomposed at 551℃ ; PeAN started to decompose at 139℃，and was totally decomposed at 477℃; PoAN started to decompose at 139℃，and was totally decomposed at 628℃.

Comparison of Methods in the Elimination of Acidity in Submicron TATB

Zeng Guiyu, Nie Fude, Xu Rong

2004, 25(4):  506-508.  doi:10.3969/j.issn.1000-1093.2004.04.029

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Methods of eliminating acidity in submicron TATB have been studied applying consecutively the ultrasonic shaking, medium treatment upon heating, dilute alkali treatment etc. The results show that ultrasonic shaking is not favouraole to the elimination of acids among submicron TATB's crystals, but it is favourable to preventing the congregation of ultra-fine TATB particles. In using dilute alkali treatment, a- tidity in the refined fluid could be rapidly reduced, but it could not effetively eliminate tne acid among the submicron TATB，s crystals and after disposing the ultra-fine TATB samples，ash remained high. The medium treatment method upon heating, favors in eliminating the acid among submicron TATB’s crystals while it brought the submicron TATB particles’ to augment in size. The results also show that when taking DMSO and water as the medium and upon heating, the ultra-fine TATB，s pH value and size could be con?trolled within a permissive range.

Robust Speech Recognition System for Military Command Application

Zhao Junhui, Kuang Jingming, Xie Xiang

2004, 25(4):  509-512.  doi:10.3969/j.issn.1000-1093.2004.04.030

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Adverse military environment often leads to many difficulties for reliable application in speech recognition. In this paper, a highly robust speech recognition system is presented based on the basic princi?ple of speech recognition and analysis of military environment. The recognition experiment shows that the proposed AbR system can achieve more than 90% recognition accuracy in adverse environment.