排序方式: 共有112条查询结果,搜索用时 31 毫秒
31.
郑文 《军械工程学院学报》2000,12(3):46-49
研究了LLP1 0B火控计算机故障分析仪的设计及实现 ;给出了该分析仪的系统组成和工作流程。 相似文献
32.
概述了热塑性互穿聚合物网络(TIPN)的研究进展及其结构特点、制各方法和熔体的流动性,并对TIPN的前景作了简要的分析。 相似文献
33.
通过对坦克车内局域网1553B协议的分析,并与一般计算机通信标准局域网做对比,指出不能用标准局域网协议和纶构取代1553B协议。参考 ISO开放系统互连的协议模型,对1553B协议进行了分层设计和进一步构想。 相似文献
34.
Nano-sized aluminum(Nano-Al)powders hold promise in enhancing the total energy of explosives and the metal acceleration ability at the same time.However,the near-detonation zone effects of reaction between Nano-Al with detonation products remain unclear.In this study,the overall reaction process of 170 nm Al with RDX explosive and its effect on detonation characteristics,detonation reaction zone,and the metal acceleration ability were comprehensively investigated through a variety of experiments such as the detonation velocity test,detonation pressure test,explosive/window interface velocity test and confined plate push test using high-resolution laser interferometry.Lithium fluoride(LiF),which has an inert behavior during the explosion,was used as a control to compare the contribution of the reaction of aluminum.A thermochemical approach that took into account the reactivity of aluminum and ensuing detonation products was adopted to calculate the additional energy release by afterburn.Combining the numerical simulations based on the calculated afterburn energy and experimental results,the param-eters in the detonation equation of state describing the Nano-Al reaction characteristics were calibrated.This study found that when the 170 nm Al content is from 0%to 15%,every 5%increase of aluminum resulted in about a 1.3%decrease in detonation velocity.Manganin pressure gauge measurement showed no significant enhancement in detonation pressure.The detonation reaction time and reaction zone length of RDX/Al/wax/80/15/5 explosive is 64 ns and 0.47 mm,which is respectively 14%and 8%higher than that of RDX/wax/95/5 explosive(57 ns and 0.39 mm).Explosive/window interface velocity curves show that 170 nm Al mainly reacted with the RDX detonation products after the detonation front.For the recording time of about 10 μs throughout the plate push test duration,the maximum plate velocity and plate acceleration time accelerated by RDX/Al/wax/80/15/5 explosive is 12%and 2.9 μs higher than that of RDX/LiF/wax/80/15/5,respectively,indicating that the aluminum reaction energy significantly increased the metal acceleration time and ability of the explosive.Numerical simulations with JWLM explosive equation of state show that when the detonation products expanded to 2 times the initial volume,over 80%of the aluminum had reacted,implying very high reactivity.These results are significant in attaining a clear understanding of the reaction mechanism of Nano-Al in the development of aluminized explosives. 相似文献
35.
为增强水泥基材料的电磁屏蔽性能,通过混凝土骨料替换的方法,实验研究了碳化硼、硼砂及石墨组合对复合材料电磁屏蔽效能的影响规律。实验结果表明单纯的碳化硼或碳化硼一硼砂作为水泥基材料骨料时,样品电磁屏蔽性能提升有限,但在添加硼介质时引入适当比例的石墨能有效改善材料的电磁屏蔽性能;另外,硼砂的添加会造成样品明显的缓凝现象,并且会对石墨导电吸波机制产生负面影响。 相似文献
36.
“空天战机”:未来世界安全吗? 总被引:2,自引:0,他引:2
美国空军试飞X-37B空天飞机,显然是"太空军事化"的开端。"空天飞机"成功试飞之后,立即引起了国际舆论的极大关注。文章论述,"空天飞机"是不是"空天战机"?它对未来战争将产生什么样的深远影响?会不会引发新的太空军备竞赛?未来的世界安全吗? 相似文献
37.
摘要:采用电化学极化手段和慢应变速率拉伸试验,结合扫描电镜观察合金断口形貌,研究了外加电位对7A52铝合金应力腐蚀开裂敏感性的影响。研究结果表明:合金在3.5%NaCl溶液中的应力腐蚀开裂敏感性与外加电位有强烈的相关性,开裂敏感性在外加电位为一0.95V时最低,外加电位起到阴极保护的作用;在外加电位为一1V时有所升高,但仍然低于开路电位条件下的敏感性;在一1.1V时最高,应力腐蚀过程以氢脆为主;在一1.2V时又有所降低,阴极析出的氢以气态逸出而降低应力腐蚀开裂敏感性。 相似文献
38.
《防务技术》2022,18(10):1810-1821
In this paper, various core-shell structured Al–Ni@ECs composites have been prepared by a spray-drying technique. The involved ECs refer to the energetic composites (ECs) of ammonium perchlorate/nitrocellulose (AP/NC, NA) and polyvinylidene fluoride/hexanitrohexaazaisowurtzitane (PVDF/CL-20, PC). Two Al–Ni mixtures were prepared at atomic ratios of 1:1 and 1:3 and named as Al/Ni and Al/3Ni, respectively. The thermal reactivity and combustion behaviors of Al–Ni@ECs composites have been comprehensively investigated. Results showed that the reactivity and combustion performance of Al–Ni could be enhanced by introducing both NA and PC energetic composites. Among which the Al/Ni@NA composite exhibited higher reactivity and improved combustion performance. The measured flame propagation rate (v = 20.6 mm/s), average combustion wave temperature (Tmax = 1567.0 °C) and maximum temperature rise rate (γt = 1633.6 °C/s) of Al/Ni@NA are higher than that of the Al/Ni (v = 15.8 mm/s, Tmax = 858.0 °C, and γt = 143.5 °C/s). The enhancement in combustion properties could be due to presence of the acidic gaseous products from ECs, which could etch the Al2O3 shell on the surface of Al particles, and make the inner active Al to be easier transported, so that an intimate and faster intermetallic reaction between Al and Ni would be realized. Furthermore, the morphologies and chemical compositions of the condensed combustion products (CCPs) of Al–Ni@ECs composites were found to be different depending on the types of ECs. The compositions of CCPs are dominated with the Al–Ni intermetallics, combining with a trace amount of Al5O6N and Al2O3. 相似文献
39.
《防务技术》2014,10(1):22-27
Ni–Al alloy coatings with different Y additions are prepared on 45# medium steel by laser cladding. The influence of Y contents on the microstructure and properties of Ni–Al alloy coatings is investigated using X-ray diffraction, scanning electron microscopy, electron probe microanalyzer, Vickers hardness tester, friction wear testing machine, and thermal analyzer. The results show that the cladding layers are mainly composed of NiAl dendrites, and the dendrites are gradually refined with the increase in Y additions. The purification effect of Y can effectively prevent Al2O3 oxide from forming. However, when the atomic percent of Y addition exceeds 1.5%, the extra Y addition will react with O to form Y2O3 oxide, even to form Al5Y3O12 oxide, depending on the amount of Y added. The Y addition in a range of 1.5–3.5 at.% reduces the hardness and anti-attrition of cladding layer, but improves obviously its wear and oxidation resistances. 相似文献
40.
《防务技术》2014,10(1):40-46
The flow behavior and dynamic globularization of TC11 titanium alloy during subtransus deformation are investigated through hot compression tests. A constitutive model is established based on physical-based hardening model and phenomenological softening model. And based on the recrystallization mechanisms of globularization, the Avrami type kinetics model is established for prediction of globularization fraction and globularized grain size under large strain subtransus deformation of TC11 alloy. As the preliminary application of the previous results, the cogging process of large size TC11 alloy billet is simulated. Based on subroutine development of the DEFORM software, the coupled simulation of one fire cogging process is developed. It shows that the predicted results are in good agreement with the experimental results in forging load and microstructure characteristic, which validates the reliability of the developed FEM subroutine models. 相似文献