热塑性弹性体在太根发射药中的应用研究

为了提高高能硝胺太根发射药的力学性能,在配方中添加了热塑性弹性体(TPUE)。测试了发射药的静态力学和定容燃烧性能,研究了TPUE添加量对发射药力学、能量和燃烧性能的影响。研究结果表明:加入1%～3%TPUE的硝胺太根发射药,在火药力(f)大于1150kJ.kg-1时,低温冲击强度提高60%以上,显示出高能量高强度的特征。随着TPUE含量的增加,火药力逐渐降低,余容α略有上升,压力指数n逐渐增大,TPUE加入量为3%时,f、α、n分别变化2%、1.4%和5.3%。     

RDX粒度对硝胺发射药力学性能及燃烧性能的影响

为研究黑索今(RDX)粒度对硝胺发射药力学性能及燃烧性能的影响,设计了RDX质量百分数为25.0%,平均粒径(D50)为30,50,150μm的3种硝胺发射药,采用摆锤式简支梁冲击试验机、落锤试验仪与密闭爆发器分别研究了其抗冲击强度、破碎情况及燃烧性能。结果表明,随着RDX粒度由150μm减小至30μm,发射药的低温(-40℃)抗冲击强度由3.46 J·cm~(-2)提高至8.99 J·cm~(-2),在落锤冲击(锤重5 kg,落高80 cm)作用下破碎度由96%降低到18%。RDX的平均粒径(D50)为30,50μm和150μm时,发射药的燃速压力指数分别为0.985、0.996和1.063。RDX粒径为30μm或50μm时,发射药u-p曲线较光滑,发射药燃烧稳定;RDX粒径为150μm时,在100~150 MPa、150 MPa~p_(dpm)的两个压力段范围内,燃速压力指数由1.125变为0.612,显示燃速压力指数存在突变,发射药燃烧不稳定。     

RDX对改性单基发射药燃烧性能的影响

为提高单基发射药(硝化棉/二硝基甲苯/邻苯二甲酸二丁酯/二苯胺,NC/DNT/DBP/DPA)的能量,在单基发射药中加入不同含量(5%、10%、15%、20%)、不同粒度(0.2,3.7,7.6,100.0μm)的黑索今(RDX),制备并得到改性单基发射药。通过密闭爆发器实验研究了RDX含量、粒度对改性单基发射药燃烧性能的影响规律。实验结果表明:在RDX粒度为7.6μm时,改性单基发射药的燃速随RDX含量的增加先降低再升高,在RDX含量为10%附近存在一个最小值;在50~p_(dpm)MPa(p_(dpm)为最大压力陡度所对应的压力值),改性单基发射药的燃速压力指数平均值均大于1。当RDX含量为5%时,改性单基发射药的燃速随RDX粒度的减小而减小;在50~p_(dpm)MPa,粒度为0.2,3.7μm的RDX改性单基发射药的燃速压力指数平均值均小于1,粒度为7.6,100.0μm的RDX改性单基发射药的燃速压力指数平均值均大于1。     

纳米纤维素纤维在高能太根发射药中的应用

为了改善高能太根发射药的力学性能,在高能太根发射药配方的基础上,添加少量(质量分数0.5%,1.0%,1.5%,2.0%)由湿木浆纤维素得到的纳米纤维素纤维(CNFs),制备了含CNFs的高能太根发射药。采用扫描电镜、热重分析仪和差示扫描量热仪研究了添加CNFs前后高能太根发射药的表面结构和热分解性能。采用简支梁冲击试验机和密闭爆发器试验研究了含CNFs高能太根发射药的冲击强度及能量性能。结果表明,少量添加CNFs可明显提高高能太根发射药的低温冲击强度,对热分解性能影响很小。与高能太根发射药(参比样)相比,添加0.5%CNFs的高能太根发射药,在-40℃低温和20℃室温下,冲击强度分别提高了30.4%和8.9%。随着CNFs含量增加,火药力逐渐降低,余容逐渐上升,燃速逐渐减小,压力指数小幅度上升。当CNFs的添加量为0.5%时,高能太根发射药的火药力为1191.91 k J·kg~(-1),余容为0.870 L·kg~(-1),压力指数为1.06,分别较参比样减少了1.9%、增加了5.1%和增加了4.2%。     

脲醛树脂/TiO2复合微球缓蚀剂的制备及性能表征

为降低发射药的烧蚀性,在不引入模板剂和结构导向剂的情况下,控制尿素和甲醛逐步聚合得到一种表面多孔的脲醛树脂微球作为基体,用溶胶-回流法在孔上沉积纳米TiO_2颗粒,形成复合微球作为缓蚀添加剂使用。扫描电镜及粒径分析结果表明脲醛树脂微球表面存在明显的斑驳纳米孔,结合傅里叶红外(FT-IR)和光电子能谱(XPS)分析,确定纳米孔可用于沉积纯度较高的纳米TiO_2,形成的脲醛树脂/TiO_2复合微球粒径分布在7～30μm。热分析结果显示,复合微球中无机组分的含量约为6%,复合微球与发射药具有良好的相容性,不会影响发射药的热分解且有利于提高发射药的热安定性。半密闭爆发器试验证实了复合微球的缓蚀性能,当复合微球相对于发射药的质量占比为3.4%时效果最好,缓蚀效率可达20.5%。该复合材料有望应用于制式发射药改性和新型高能发射药设计。     

改性单基发射药的燃速模型

为了研究以5/7单基发射药为基体药,硝化甘油(NG)为浸渍剂,聚酯为包复剂所组成的改性单基发射药的燃烧性能,对改性单基发射药的浸渍层分布,燃烧过程中药型尺寸及能量特性的变化进行了理论分析和实验验证。制备了NG浸渍量分别为10%和15%两个样品,进行了密闭爆发器试验、显微切片照相,用所建理论模型计算了试验结果。结果表明:NG浸渍量为15%时,火药力提高了10.14%,浸渍深度约0.168 mm,小于150 MPa,计算所得基体药u-p曲线高于改性单基发射药u-p曲线;大于150 MPa,两者u-p曲线重叠。当NG和聚酯在推进剂中的浸渍量分别为15%和2.5%时,在NG和聚酯浸渍量配比合适的条件下,改性单基发射药的火药力和燃烧渐增性在一定范围内可以做到同时增加。     

二氧化钛在发射药燃烧中的阻燃作用研究

通过差热分析(DTA)和密闭爆发器两种方法，研究了锐钛型二氧化钛(TiO2)在太根发射药中的阻燃作用。结果显示，差热试验中含二氧化钛的太根药，在900℃附近存在二氧化钛晶型转变的吸热效应；定容燃烧试验中，含二氧化钛的太根药燃烧速度明显降低。分析认为，含二氧化钛的太根药燃烧过程中主要存在下列阻燃的因素：二氧化钛自身晶型转变的吸热效应和阻燃剂粒子在太根药中的表面覆盖效应。     

胶粘固结发射药定容燃烧规律研究

为了探索胶粘固结发射药定容状态下的燃烧规律,由密闭爆发器定容状态方程推导出粘结剂燃烧结束点相关参数的确定方法,并对不同胶粘固结发射药进行计算。结果表明:粘结剂燃烧结束时基体药的燃烧质量百分数较大,共同燃烧阶段不可忽略;增大粘结剂含量会使基体药的燃烧质量百分数增大、粘结剂的燃烧时间和达到最大压力的时间延长,并使最大压力变小;基体药粒径越小,粘结剂与基体药燃烧阶段基体药燃烧质量百分数越大。     

基于微焦点CT技术的DAGR125发射药内部微结构分析

通过传统溶剂法制备了含25%RDX的DAGR125发射药,采用微焦点X射线断层扫描(μ-CT)技术和扫描电镜技术,研究了发射药内部微结构及形成原因,定量分析了微结构特征和分布。结果表明:发射药整体结构均匀密实,微观结构中仍存在大量均匀分布的微缺陷,与药体相比,其密度相对较低;微缺陷平均体积为0.575×10-3mm3,总体积比率为12.12%;微缺陷中可能存在微空隙,但尺寸极小,难以分辨;发射药内部结构由取向分布的NC区和海岛分布的富RDX区构成,微缺陷产生于富RDX区;发射药内部存在明显的气孔缺陷,尺寸相对较大,且主要分布于药柱轴向中心部位。本研究表明微焦点CT技术是研究高能异质发射药内部微结构的有效手段。     

喷雾干燥法中溶剂对RDX颗粒形貌和性能的影响

采用喷雾干燥法制备微米级球形黑索今(RDX)。研究了乙酸甲酯、乙腈、丙酮、丁酮4种低沸点溶剂对制备的RDX颗粒形貌和性能的影响。采用扫描电镜(SEM)、差示扫描量热法(DSC)分析了所得RDX颗粒的形貌和热分解特性,并测试了其撞击感度。结果表明:喷雾干燥法制备的RDX粒径为1~5m,其中以丁酮为溶剂喷雾干燥制备的RDX颗粒形貌最好,颗粒形状均为球形,分μ散均匀,颗粒表面光滑并且缺陷较少;与原料RDX相比,喷雾干燥法制备的RDX颗粒的撞击感度均明显降低,特性落高较原料RDX提高了2倍以上;热分析结果表明,喷雾干燥法制备的球形RDX热分解的表观活化能(E)和热爆炸临界温度(Tb)均有所降低,其中以乙酸甲酯为溶剂喷雾干燥制备的RDX的E和Tb分别降低了33.35kJ·mol-1和7.77℃。     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS （geographical information system） data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.     

Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.     

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.     

Algorithm for Multi-laser-target Tracking Based on Clustering Fusion

Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.     

Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles

The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent ＂explosion of terms＂. Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.     

A Study on the Estimation of Aeroheating upon the Warhead Nose at Supersonic Speed

An expression for estimating the aeroheating on a warhead nose at different supersonic speeds is proposed by incorporating CFD （computational fluid dynamics） and the least-square method. Compared with the traditional estimation formula, the expression is more accurate, convenient and can be used in the optimized design of warheads. The error from the result obtained in the test of a ball cartridge flight is less than 3 %. It satisfies the engineering requirements.