微波法制备无硫膨胀石墨结构特征研究

以黑龙江萝北石墨为原料,采用H3PO4和CH3COOH插层石墨,微波膨化制备了无硫膨胀石墨.采用IR、XRD 和 SEM 测试技术进行结构表征,并对比不同捅层剂制备的膨胀石墨微波膨化的膨胀效果与结构差异.研究表明:对于磷酸法制备的膨胀石墨,其微波膨胀效果与结构完整性均优于冰乙酸法制备的膨胀石墨,磷酸法制备的膨胀石墨的膨胀倍率可达到282 mL·g-1.     

膨胀石墨吸附能力的表征

通过对所选膨胀石墨及可膨胀石墨的 XRD、SEM 以及 DTA 的测试分析,发现膨胀石墨内部孔结构的丰富与否与质量损失率的变化规律是趋于一致的,而与膨胀体积的变化规律不尽相同;吸附实验表明:膨胀石墨在针对表面吸附油进行处理时,是缠绕空间起主导作用,而在针对含油污水中小颗粒乳化油的处理时,则是内部孔结构起主导作用:通过对膨胀体积和质量损失率的控制,可以实现对缠绕空间和内部孔结构的控制,从而也达到了对表面浮油和小颗粒乳化油分工吸附的目的。     

改性膨胀石墨衰减红外/毫米波性能研究

为提高膨胀石墨的红外/毫米波衰减性能,采用化学镀铜和掺杂二茂铁两种方法对可膨胀石墨进行技术改性,并测量了改性后所制备的膨胀石墨对红外(3~5、8~14μm)、毫米波(3、8 mm)的衰减性能。结果表明:改性后的膨胀石墨比单纯的膨胀石墨具有更好的红外/毫米波衰减性能,且掺杂二茂铁改性膨胀石墨的红外/毫米波衰减性能明显优于化学镀铜改性膨胀石墨。     

表面包覆对可膨胀石墨膨胀和毫米波衰减性能影响研究

采用3种包覆剂对两种可膨胀石墨进行了表面包覆,测试了包覆前后可膨胀石墨的膨胀性能,结果表明包覆剂1对可膨胀石墨的膨胀性能无明显影响,包覆剂2和包覆剂3使可膨胀石墨的膨胀倍率增加。此外,测试了由不同包覆剂处理的可膨胀石墨制备的发烟剂对毫米波的衰减性能,结果表明包覆剂对毫米波衰减性能有一定影响,其中包覆剂2的影响显著。     

膨胀石墨对8mm波动态衰减性能的影响因素研究

根据衰减机理,通过测试手段,研究了膨胀石墨动态衰减8mm波的影响因素。试验结果表明：保持粒子形态完好,增大膨胀石墨的倍率及其在空间的浓度．选用规格为9932350的可膨胀石墨有利于对毫米波的衰减;并对瞬时膨化剂膨化出来的膨胀石墨和马弗炉膨化出来的膨胀石墨的衰减性能进行了对比,发现瞬时膨化剂膨化出来的膨胀石墨衰减效果更好。     

可膨胀石墨在烟剂应用中的一个评价方法--膨化率的测定

从烟幕颗粒本身的特性着手,以硫酸插层的可膨胀石墨为基准,建立了测试可膨胀石墨用于毫米波干扰发烟剂中膨化率反推的测试方法,并拓展到可计算不同插层的可膨胀石墨膨化率的范围.     

膨胀石墨干扰8毫米波特性研究

研究了膨胀石墨对8 mm电磁波的干扰特性,指出膨胀石墨的膨胀尺度是影响遮蔽效果的重要参量,并依据毫米波雷达的衰减机制确定了酸化石墨的粒径与厚度。应用扫描电镜观测样品膨胀前后的表观形貌。以H2S04-CH3COOH-GIC为例,对膨胀石墨型气溶胶的粒度分布、沉降速度及其在8 mm波频段内的衰减率进行了测试、计算与分析,研究了膨胀倍率随膨化温度、时间变化的规律。研究结果表明,膨胀石墨是一种高效、新颖的发烟剂,对军用毫米波雷达(36 GHz)干扰作用显著。     

膨胀石墨烟幕对1.06μm和10.6μm激光的消光特性研究

为测试膨胀石墨烟幕红外激光消光特性,在分析膨胀石墨烟幕消光机理的基础上,通过测量其在不同时段的烟幕平均质量浓度和平均激光透过率,得到了膨胀石墨烟幕对1.06μm近红外和10.6μm远红外激光的质量消光系数分别为1.149 8m<'2>/g和0.820 5m<'2>/g.结果表明,膨胀石墨烟幕对两个波长的红外激光具有良好的消光和干扰效果,在光电对抗领域具有广阔的应用前景.     

可膨胀石墨用作抗红外/毫米波双模发烟剂的研究

为了获取一种性能较佳的毫米波发烟剂材料,就JF-150可膨胀石墨对3mm和8mm波的衰减性能进行了实验研究,在此基础上,以JF-150可膨胀石墨作为重要组分设计了一种抗红外/毫米波发烟剂配方,采用红外热像仪及毫米波辐射计测试了该发烟剂形成的烟幕对3mm和8mm波的衰减特性。结果表明,可膨胀石墨对3mm和8mm波单程最大衰减分别为17.0dB、16.6dB,优于铝箔条衰减效果;60g可膨胀石墨发烟剂对3mm和8mm波单程最大衰减值均大于10dB,干扰时间约为20s。可膨胀石墨是一种用于制造抗红外/毫米波双模发烟剂的良好材料。     

可膨胀石墨发烟剂对毫米波衰减性能的实验研究

本文在分析可膨胀石墨膨胀机理的基础上,实验研究了可膨胀石墨发烟剂产生的膨胀石墨烟幕对3mm波、8mm波的衰减性能。结果显示,膨胀石墨烟幕能够较好地衰减3mm波和8mm波辐射,其衰减性能随可膨胀石墨的粒度减小而下降,利用可膨胀石墨发烟剂产生的烟幕来干扰毫米波雷达探测是可行的。     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

Expert Systems Aimed at General Design of Projectiles

Expert systems aimed at the general design of projectiles can implement a series of intelligent designs, such as the design of HE shell, the scheme expounded and proved, the emulation analysis and calculation, etc. Aiming at the product design feature, the expert system adopts the object-oriented knowledge representation and all kinds of inference control engines to describe and reason the relevant knowledge regarding the product through the microcomputer. It embodies the foundation of emulation analysis and simulated manufacturing of the shell. It makes use of the method that knowledge expression is combined with condition of inference to carry out the overall design and emulation and reference.The paper gives the ways through which the functions can be achieved, gives the modularization of reference and the design methods of systematization, puts forward the method of knowledge expression and working interface, and supplies a platform for similar products of the shell category that can be quickly designed.     

Parameter Identification for the Valve Control Cylinder System of a Hydraulic Manipulator

In mechanical, hydraulic and electronic systems, the determination of system parameters is often challenging because liquid parameters often change significantly, due to variations in working and environmental conditions. Therefore, it is of significant practical importance to identify those parameters through experimental procedures. A systematic approach to identifying parameters in the valve controlling cylinder system of hydraulic manipulators is provided. It first derives the transfer function of the system, and then uses P control of PID control to predict system parameters. The predicted parameters are further validated using PID control. The prediction through simulation using MatLab language is utilized, which agrees well with experimental results.     

Three-dimensional Numerical Simulation of Combustion Field in the Combustion Chamber

In order to study the effect of rotation on the combustion in the underwater vehicle, a two-phase turbulent combustion process is described with Reynolds stress turbulence model, eddy-dissipation turbulent combustion model, P-1 radiation model and particle tracking model of liquid. The flow in the rotating combustion chamber is simulated at two different working speeds, 0 r/min and 1 000 r/min by Fluent software. The temperature, gas velocity, static pressure of wall and fuel concentration are computed and compared. The results show that the combustion in rotating combustor is faster and more effective.     

Software Communication Architecture Implementation and Its Waveform Application

This paper attempts to do a research on the development of software defined radio（SDR） based on software communication architecture（SCA）. Firstly, SCA is studied and a whole reference model of SCA3.0 core framework （CF） is realized; Secondly, an application-specific FM3TR waveform is implemented on the platform of common software based on the reference model; Thirdly, from the point of view of real-time performance and software reuse, tests and validations are made on the above realized CF reference model and FM3TR waveform. As a result, the SCA-compliant SDR has favorable interoperability and software portability and can satisfy the real-time performance requirements which are not too rigorous.     

Dynamic Simulation of the Tank Gun Recoil Response

By using the ATV module of MSC. ADAMS, the dynamic simulation of recoil response of tank gun is analyzed.How the recoil force affects the bodywork and the suspension during gun firing, as well as the changing status of the gun muzzle‘s velocity are gained. All results and analyzing methods are offered for the designing basis of optimizing tank vehicle-gun match. The constructive exploration is beneficial to improving the general capability of tank.     

Survey of Controllable Suspension System for Off-road Vehicles

The controllable suspension system can improve the performances of off-road vehicles both on road and cross-country. So far, four controllable suspensions, that is, body height control, active, semi-active and slow-active suspensions, have been developed. For off-road vehicles, the slow-active suspension and the semi-active suspension which have controllable stiffness, damping and body height are more appropriate to use. For many years, some control methodologies for controllable suspension systems have been developed along with the development of modern control theory, and two or more original control methods are integrated as a new control method. Today, for military or civilian off-road vehicles, the R&D of controllable suspension systems is ongoing.     

Passive Acoustic Radar for Detecting Supersonic Cruise Missile

A Passive Acoustic Radar is presented as a necessary complement to electromagnetic wave radar, which will be expected to be an effective means for detecting cruise missiles. Acoustic characteristics of supersonic flying projectiles with diverse shapes are expounded via experiment. It is pointed out that simulation experiment could be implemented using bullet or shell instead of cruise missile. Based on theoretical analysis and experiment, the ““acoustic fingerprint““ character of cruise missile is illustrated to identify it in a strong noise environment. After establishing a locating mathematical model, the technique of acoustic embattling is utilized to resolve a problem of confirming the time of early-warning, considering the fact that velocity of sound is much slower than that of light. Thereby, a whole system of passive acoustic radar for detecting supersonic cruise missile is formed.     

Super-resolution Restoration of Remote-sensing Images

A novel image restoration scheme, which is super-resolution image restoration algorithm Poisson-maximum-afterword-probability based on Markvo constraint （MPMAP） combined with evaluating image detail parameter D, has been proposed. The advantage of super-resolution algorithm MPMAP incorporated with parameter D lies in the fact that superresolution algorithm MPMAP model is discrete, which is in accordance with remote-sensing imaging model, and the algorithm MPMAP is proved applicable to linear and non-linear imaging models with a unique solution when noise is not severe. According to simulation experiments for practical images, super-resolution algorithm MPMAP can retain image details better than most of traditional restoration methods; at the same time, the proposed parameter D can help to identify real point spread function （PSF） value of degradation process. Processing result of practical remote-sensing images by MPMAP combined with parameter D are given, it illustrates that MPMAP restoration scheme combined PSF estimation has a better restoration result than that of Photoshop processing, based on the same original images. It is proved that the proposed scheme is helpful to offset the lack of resolution of the original remote-sensing images and has its extensive application foreground.     

Design and Simulation of TF and TA Controller for Missile

A nonlinear terrain following(TF) and terrain avoidance(TA) controller is proposed for missile control systems. Based on classical TF algorithm (adaptive angle method), a new method for TF controller is proposed by using angle of attack. A method of obtaining terrain outline data from digital elevation map (DEM) for TF control is discussed in order to save store space. A TA algorithm is proposed by using bank-to-turn technique. The block control model, which is suitable for backstepping design, is given for nonlinear model of missile. Making full use of the characteristics of the system and combining block control principle and backstepping technique, a robust controller design method is proposed. Uncertainties in every sub-block are allowed, and can be canceled by using the idea of nonlinear damping. It is proved that the state tracking errors are converged to a neighborhood of the origin exponentially. Finally, nonlinear six-degree-of-freedom simulation results for the missile model are presented to demonstrate the effectiveness of the proposed control law.