共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
纳米多孔硅粉的化学腐蚀及其理化性质表征 总被引:1,自引:1,他引:0
以纯度大于99%,粒径20μm以下的硅粉为原料,以HF、HNO3、蒸馏水及亚硝酸钠为腐蚀介质,采用化学腐蚀法制备纳米多孔硅粉。利用扫描电镜、全自动比表面积仪以及傅里叶变换红外光谱仪对纳米多孔硅粉进行了表征。制备了多孔硅/高氯酸钠复合材料并进行了燃烧实验。结果表明,腐蚀体系中硝酸浓度是影响孔径分布的主要因素。腐蚀时间则是增大纳米多孔硅粉比表面积的关键因素。最佳腐蚀条件为硝酸浓度5.2%,腐蚀时间120 min。制备的纳米多孔硅粉为介孔材料,表面存在大量的硅-氢键,比表面积达58.2264 m2·g-1。制备的多孔硅/高氯酸钠复合材料能剧烈燃烧,伴有爆燃现象,能用作绿色点火药剂或燃烧剂。 相似文献
3.
纳米碳具有比表面积大、安全钝感、燃烧产物绿色无污染、与反应物接触面积大及易改性等优点,在调节高能炸药、推进剂、铝热剂等含能材料性能方面具有一定优势。本文总结了纳米碳对含能材料的分解特性、感度、力学性能、燃烧性能的影响、以及其用于含能材料检测、吸附、降解方面的应用进展。分析了典型纳米碳,如纳米金刚石、富勒烯、纳米碳纤维、碳纳米管和石墨烯在含能材料改性中的作用机理,并指出纳米碳在含能材料应用中存在的问题,提出未来的发展方向:(1)优化纳米碳制备工艺,解决纳米碳成本高、易团聚和批次差异较大等问题;(2)扩大纳米碳应用范围,探究洋葱碳等新型纳米碳结构以及改性纳米碳对含能材料性能的影响;(3)根据特定环境与纳米碳调节机理,优化纳米碳在含能材料性能提升中的应用条件。 相似文献
4.
在黑索今(RDX)/间苯二酚-甲醛树脂(RF)纳米结构复合含能材料制备的基础上,研究了RF气凝胶和RDX/RF纳米结构复合含能材料的孔结构,计算了含10%、30%、50%、70%、80%RDX的复合材料RDX/RF的比表面积、总孔体积、平均孔径,并对RF气凝胶和不同复合材料的吸附脱附等温线、中孔分布和微孔分布进行了比较。用扫描电子显微镜(SEM)对其微观形貌进行了表征,利用X射线粉末衍射仪(XRD)对复合材料中RDX颗粒的晶粒度进行了研究,在34~38 nm之间。研究表明:RDX/RF复合材料的孔径在50 nm以下,随RDX含量的增加,比表面积、总孔体积变小,平均孔径则变大;通过RF气凝胶和RDX/RF纳米复合含能材料的吸附脱附等温线、中孔、微孔分布以及中孔微分总孔体积、微孔微分总孔体积的变化比较,认为RDX的填充对气凝胶的中孔影响较大。 相似文献
5.
6.
纳米多孔硅复合材料爆炸反应的实验与理论研究 总被引:10,自引:7,他引:3
纳米结构多孔硅具有极高的孔隙率和比表面积,在其孔隙内掺入硝酸盐组分形成一种可发生爆炸反应的复合材料.实验表明①多孔硅的比表面积越高,与相关组分的接触面积越大,爆炸越迅猛;②新鲜制备的多孔硅较易发生爆炸,经过存放后需要更高的触发能量才能发生爆炸;③多孔硅-硝酸盐复合材料的爆炸过程与硝酸盐的种类有关,在实验条件下,掺碱金属硝酸盐的复合材料不发生爆炸,而掺镧系金属硝酸盐的复合材料可以发生爆炸;④在镧系硝酸盐中,硝酸钆和硝酸镧最为敏感,在滴加较低浓度时就发生爆炸,而硝酸铒需要在滴加较高浓度时才会发生爆炸.我们依据已有的硅氢加成反应和过渡金属催化炸药分解反应,首次提出了多孔硅-硝酸盐复合材料的微观结构模型,使用这种模型可以合理地解释实验中的爆炸现象. 相似文献
7.
8.
9.
硅基微雷管的原位装药及性能研究 总被引:3,自引:3,他引:0
微机电安全保险机构芯片化集成技术的发展,对基于微机电制造工艺的硅基微雷管提出了需求,雷管装药尺寸的减小要求含能材料感度高、起爆威力大。为解决微小尺寸敏感药剂装填的技术难题,文中采用原位生成多孔叠氮化铜的方法,对硅基微雷管进行装药研究。依据GJB/Z 377A-1994 感度试验用兰利法测试硅基微雷管的发火感度,使用电流环测试硅基微雷管发火实际利用的能量,同时对输出威力进行定性测试。测试结果表明:发火电路用充电电容为33 μF时,硅基微雷管的平均发火电压为7.89 V,输出威力可以起爆六硝基杂异伍兹烷(CL-20)装药。 相似文献
10.
对纳米复合材料的研究进展进行了综述,例举多种纳米复合材料的制备方法: sol-gel法、溶剂/非溶剂法、高能研磨法、多孔金属/填充物复合法.对这些制备方法及制品的性能进行了分析,认为纳米复合材料提供了研究含能材料的新角度,改进了纳米粉体含能材料储存使用过程的安全性,减轻了粒子团聚现象,有利于充分发挥材料的纳米特性.纳米复合含能材料的制备技术、制备工艺参数及制品结构对其性能的影响规律研究还处在探索阶段,今后还需理论和实践两个方面进行更加深入地分析、探讨. 相似文献
11.
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. 相似文献
12.
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. 相似文献
13.
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. 相似文献
14.
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. 相似文献
15.
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. 相似文献
16.
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. 相似文献
17.
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. 相似文献
18.
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. 相似文献
19.
The paper introduces the performances of magnetostrictive actuators and its applications, discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator, and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material. The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states, and can be used in lowfrequency vibration control system of precise equipment. 相似文献
20.
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. 相似文献