某火工品老化性能评估研究

在温度为60℃、相对湿度为95%的加速老化试验条件下,对某火工品的单发作用时间变化情况进行了研究。研究结果表明,随着老化时间的延长,其单发作用时间均值也延长,且在加速老化21天、35天和45天,被测样品的单发作用时间最大值呈线性增长;当加速老化到56天,该火工品被测样品的可靠度降低为98.98%,当老化到67天,其可靠度降低为15.06%。     

材料老化对火工品性能影响研究

为了掌握某火工品材料老化对其性能的影响,采用高温加速老化试验,对其电极电阻及PETN炸药粉末比表面积在老化过程的变化情况进行了测试分析,并通过该火工品单发作用时间测试,研究了电极及PETN粉末老化对其性能的影响。结果表明:在高温加速老化过程中,该火工品电极电阻无显著性变化,其装配成的火工品单发作用时间也无明显变化,但其PETN炸药粉末比表面积随老化时间延长出现了明显下降,采用经不同时间老化后的PETN装配火工品,测得单发作用时间随比表面积减小而延长。     

RDX基浇铸PBX的老化性能

采用-55~71℃温度循环老化试验,研究了RDX基浇铸高聚物粘结炸药(PBX)老化时,随时间的外观变化、结构完整性、质量/体积变化率、机械感度、力学性能及发射安全性。进行了65,75,85,95℃老化试验和老化样扫描电镜(SEM)及动态力学分析(DMA)的研究。结果表明,25个温度循环后,PBX炸药装药内部无可见裂纹和气孔,结构完整性未发生变化,质量/体积变化率小于1%,撞击感度增加到16%,在锤重400 kg和落高3 m的撞击条件下,未发生爆炸,PBX的抗压强度增加、压缩率下降,力学性能显著劣化。65℃恒温老化252 d后,抗压强度增加47.5%,压缩率下降9.8%。随老化时间延长,β松弛的动态力学损耗峰值(tanδ)降低,网络交联程度提高,与填料之间的结合更为紧密,显示后固化交联反应是力学性能劣化的原因之一。     

电爆管失效模式及影响因素研究

采用加速老化试验技术,在温度为71℃和温度为71℃、相对湿度分别为50%和80%条件下,对某电爆管在老化过程中的失效模式进行了研究。结果表明,老化后,该电爆管压敏电压值均较老化前降低,尤其是经含有湿度的双因素加速老化试验后,其压敏电压值下降更明显,而其电阻、发火时间、输出气体压力等性能指标却无明显变化。通过对电爆管压敏电压下降影响因素研究,结果发现,灌封胶配制不均是导致其压敏电压值在湿度环境中下降的主要原因。     

加速老化对RDX基压装PBX炸药性能的影响

为研究聚丁二烯橡胶(BR)粘结剂在老化过程中对黑索今(RDX)基压装高聚物粘结炸药(PBX)性能的影响,采用71℃高温加速老化试验,测试了老化前后药柱的质量、体积、真空安定性、力学性能和机械感度,利用扫描电镜(SEM)和X射线光电子能谱(XPS)观察了炸药微观结构、元素含量和化学环境的变化情况。结果表明,经过高温长贮后,药柱体积和质量的变化率都小于1%,未见裂纹等明显缺陷;抗压强度增加74%,抗拉强度增加117%,撞击感度从8%降至4%,摩擦感度从18%降至8%;高温老化过程中炸药的安定性没有发生明显的变化。分析认为,在加速老化过程中,由于碳碳双键的不稳定性,药柱中的BR粘结剂发生氧化交联反应,使交联度提高,并受热软化、铺展,分布均匀化,使包覆和粘结效果增强,从而提高了炸药的力学性能并降低了机械感度。     

含改性氯酸钾烟火药剂的安全性研究

为了研究含改性氯酸钾的烟火药剂的安全性,采用绝热加速量热仪、撞击和摩擦感度仪等,对由改性前后氯酸钾组成的烟火药剂的热安全性和摩擦感度、撞击感度进行了对比测试.结果表明,含改性氯酸钾的烟火药剂初始放热温度提高了36.08℃;达到最大放热速率的时间延长了6倍多;单位质量最大压力减小了0.63MPa·g-1;绝热温升降低了95.99℃;摩擦感度降低了64%,撞击感度降低了72%.含改性氯酸钾组成的烟火药剂安全性明显提高.     

加速老化对电火工品电阻与发火时间的影响

试验测定了不同加速老化时间电火工品的电阻与发火时间,分析确定了影响电阻与发火时间变化的原因与规律。选择了80发试验样品,在90℃温度下对其进行加速老化,测定了老化过程中桥丝电阻的变化,最后对不同老化时间后试验样品的发火时间进行了测定。试验与分析表明：由于药剂对桥丝的氧化,样品的桥丝电阻可增加2％以上;由于药剂的分解使其能量下降,样品的发火时间增长,出现迟发火和瞎火。     

某电爆管贮存老化性能研究

为了研究某电爆管在贮存过程中的性能变化情况,采用加速寿命试验的方法,在温度为71℃和温度为71℃、相对湿度为50%的加速老化试验条件下,对该电爆管的性能变化情况进行了试验研究。试验结果表明,除了该电爆管压敏电压受环境湿度影响较明显外,其电阻、发火时间及输出气体压力均在设计技术指标范围内。     

不同加速寿命时间点上不同桥丝材料电阻变化研究

在恒定温度、湿度的条件下,研究了镍络丝和金丝两种不同桥丝材料的电极电阻在加速寿命试验后各个不同贮存时间点的变化情况,并对不同寿命时间点的电阻均值进行t-显著性检验。研究结果表明,金丝电极电阻在室温下贮存20天及在温度(50±2)℃、湿度95%条件下贮存9天、14天和21天后都较初始电阻有显著性变化,而镍铬丝电极电阻却变化不明显。     

一种电容储能焊接火工品泄漏率变化规律研究

为了解长期贮存对储能焊接火工品密封性能的影响,对不同焊接设备装配的产品进行老化试验前后的泄漏率测试,通过开展不同时间的老化试验,分析老化时间对产品密封性能的影响。结果表明:老化环境会对储能焊接火工品的密封性能造成一定程度的影响,并且随着老化时间的增加,火工品的密封性能出现显著的降低,甚至无法满足国军标的要求。后续工作中需要对焊接产品结构、焊接工艺参数进行系统研究,以期提高储能焊接火工品在长期贮存条件下的密封性能。     

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.     

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.     

Influence of Installing Error on the Surface Shape Precision of the Axial Symmetry Aspheric Workpiece in Lapping

A method to calculate the surface shape error, which is caused by the installing error between the workpiece and the lapping tool in the process of form lapping, is proposed. The mathematical model which the installing translation error influences on the workpiece surface shape error is established. The changing rule of the error is simulated through the calculating example of the paraboloid workpiece. The results indicate that the surface shape error of the workpiece is increasing with the increase of the installing translation error, it is also increasing gradually along the center point of the curve surface to the edge, and the influence is severer to the curve surface with great curvature than that of the small curvature when the translation error is the same.