基于PXI总线的雷达装备通用模块接口电路设计

为做好对部队雷达装备日常性能的检测与维护，充分保障其性能的可靠性，研制开发了基于PXI总线的雷达装备性能检测模块。在对模块的接口电路的设计中，采用目前流行的PCI9030接口芯片，简化了设计难度。经实验验证，采用该方案的各模块都实现了相应的功能，达到了预期的设计目的。需要改进的方面是接口电路中热插拔部分性能的可靠性有待进一步提高。     

热射流起爆过程的数值模拟

采用改进的化学非平衡流解耦方法处理Euler反应流方程,并以H2/air 9组分21方程模型对竖直喷注的热射流起爆过程进行了二维数值模拟。对流项采用五阶WENO离散格式,时间推进采用二阶Runge-Kutta方法。详细分析了热射流以不同速度、入射位置、入射宽度和入射倾角喷射时在爆震管内形成的流场,总结了射流参数状态影响起爆的一般规律;解释了激波、火焰的相互作用对"热点"的形成以及转变为爆震的影响,特别是激波反射对"热点"形成的促进作用。结果表明,爆震波通常由火焰面和固壁附近狭长未燃区域中的"热点"产生。"热点"向爆震波发展的过程是过驱爆震阶段,存在三波结构。为了实现快速起爆,应当增大射流入射速度、贴近侧壁并以适当入射角度喷射热射流。     

热壁条件下油气热着火关键因素探究

设计了受限空间内高温热壁条件下的油气热着火的实验系统.基于系统的实验和分析,探究了受限空间环境温度、湿度、压力、热壁温度对油气热着火发生的影响.实验发现:油气热着火概率随着热壁温度和环境温度的升高、湿度的减小而增加;油气混合物在汽油自燃点附近开始快速化学反应,油气热着火的最低临界温度为783 K;油气热着火存在三角形的着火压力半岛,且着火压力下限随热壁温度升高而降低,着火压力上限随温度升高而提高.     

Place–time correlation of robbery incidents in metropolitan Lagos: a Mantel index analysis

This article investigates the correlation of space and time in the clustering of robbery incidents in metropolitan Lagos. Analysis was carried out on 781 selected robbery incidents in 2013. Using the Mantel index to correlate place and time intervals for pairs of robbery incidents, the results show that robberies are respectively concentrated in residential areas, transport nodes and public places, peaking at midnight during weekdays. The results further show that this concentration is most likely greater than what would be expected on the basis of a chance distribution. The study concludes that various factors may exist which cause clusters of robberies to occur in these places at these times.     

CompactPCI系统中热插拔技术的运用

针对目前工业计算机与电信领域CompactPCI系统的高可靠性工作需求,运用CompactPCI总线支持热插拔技术来解决如何提高系统的可靠性.在设计方面提出了5个硬件设计要点和1个软件设计结构框图,形成一个完整的CompactPCI系统热插拔技术解决方案.有效的提高了系统的可靠性,在工业计算机与电信领域未来的发展中具有广阔的应用前景.     

“strategic technology＂研究热点与趋势分析

以Web of Science数据库相关文献为数据源,运用Excel图表工具及CitespaceⅡ可视化知识图谱软件进行数据信息分析,绘制了共现网络图谱,通过解读图谱.对国外“strategic technology”研究热点及趋势进行了初步探析,得出“strategic technology”研究热点与前沿的相关结论,对国内战略技术的研究与政策制定具有一定的参考价值.     

效能评估研究热点分析

采用计量学方法,以CNKI、SCI数据库中的文献为数据源,运用CitespaceⅡ、Excel软件对效能评估中文、英文相关文献进行分析,通过对比方式,得出国内外效能评估研究热点的相关结论,并将主要关键词以时间轴的顺序区分归类,对效能评估的研究具有一定的参考价值     

The legality of unmanned aerial vehicles outside the combat zone: a case study of the Federally Administered Tribal Areas of Pakistan

The drone is the latest tool to promote interests of a nation-state. It is clear that USA as well as other major powers anticipate that robotics will play a key role in future warfare. Today, more than 70 countries have already acquired drone technology and many others are desperate to join the ranks. This urge for drone technology will ultimately lead to a “boundless and borderless war without end.” In the case of Pakistan, the US drone campaign has raised some important issues regarding how their use could, or should, be regulated in the future. This article analyses the legal issues raised by the US's use of drone technology in non-combat zones, such as Pakistan. It is argued that a reckless disrespect of Pakistan's sovereignty has had adverse implications and consequences for the legitimacy of the Pakistani government. Drone strikes have prompted instinctive opposition among the Pakistani population, hurt their feelings and estranged them from the government. This in turn has added to Pakistan's instability and stimulated a ground-swell of animosity toward the USA.     

合成双射流冲击平板流场结构与模态分解分析

为揭示合成双射流冲击平板流场结构特征,通过大涡模拟方法对合成双射流冲击平板流动进行了仿真,采用有限时间Lyapunov指数方法对流场的拉格朗日涡结构进行了识别,并与欧拉框架下的速度矢量和涡量结果进行了对比分析。结果表明,在合成双射流两股射流交替作用下,射流核心区涡系结构较为复杂且涡量丰富,远离核心区存在一对稳定的涡结构,且拉格朗日涡结构与涡量对应较好,为合成双射流冲击冷却的布局设计提供了指导。另外,流场本征正交分解表明,第一阶模态关于激励器出口中心轴线大致对称,其能量占总体能量的35%,前6阶模态的能量占80%;根据前6阶模态所反映的流场特性,合成双射流冲击平板流场具有高度的对称性。     

界面改性对SiCp/Cu复合材料导热性能的影响

采用磁控溅射法结合结晶化热处理工艺在SiC颗粒表面成功制备了金属Mo涂层,分析Mo涂层的成分和形貌;采用热压烧结工艺制备SiCp/Cu复合材料,重点对比分析Mo界面阻挡层厚度对复合材料导热性能的影响。结果表明:磁控溅射法能够在SiC颗粒表面沉积得到Mo涂层,随溅射时间的延长,Mo涂层的厚度增加、粗糙度增大,且磁控溅射后SiC颗粒表面直接得到的Mo涂层为非晶态,结晶化热处理后,变为致密平整的晶态Mo涂层。磁控溅射时间对Mo涂层厚度和复合材料导热性能影响明显。随磁控溅射时间的增加,复合材料的热导率呈先增后减趋势。采用磁控溅射9h镀Mo改性并经过800℃结晶化热处理的SiC复合粉体在850℃下热压烧结制备的SiCp/Cu复合材料(VSiC=50%),其热导率达到了最高值274.056W/(m·K)。