11 组元化学反应气体粘性激波层钝体绕流数值计算

本文采用１１组元化学模型对双曲体粘性激波层化学非平衡绕流流场进行了数值计算,给出了压力、温度,Ｎ＋２、Ｏ＋２、Ｎ＋、Ｏ＋和ＮＯ＋摩尔浓度及ｅ－数密度在驻点的分布,并与７组元、５组元的计算结果作了比较。     

双基地中两坐标收站的三维定位跟踪算法

文中讨论了Ｔ／Ｒ—Ｒ型双基地系统中无俯仰信息收站对运动目标的三维定位跟踪能力;通过若干观测点上测量数据的组合,较好地实现厂对运动目标的三维定位跟踪,从而可以将目标的高度信息从变化的距离和之差的测最值中提取出来。文中以仿真手段证明了这种方法的可行性。     

高空滑移条件对化学非平衡粘性流动的影响

本文用数值方法计算了不同高度滑移边界条件对钝体绕流流场特性的影响。采用化学非平衡粘性激波层控制方程,边界条件含壁面滑移、激波滑移和无滑移条件。计算结果表明,考虑滑移条件后,激波层较厚,激波处的电子数密度为一有限值。文中给出了计算结果,并与其它文献的结果作了比较。     

氧乙炔火焰喷熔层的多次冲击抗力

本文针对军械零件的服役特点,采用小能量多次重复冲击压缩加载,对七种镍基和铁基合金粉末的氧乙炔火焰喷熔层进行试验研究,其组织、性能和多冲接触疲劳抗力(简称多冲抗力)表明,本文的试验方法可灵敏地反映喷熔层塑性的差异。为使喷熔层获得较高的多冲抗力,文中关于合金粉末的成份、喷熔层的硬度与厚度,以及母材强度优选的结论对工程应用具有指导意义.     

燃烧室前缘扩张角对旋转爆震冲压发动机的影响

针对圆柱形隔离段-燃烧室构型的旋转爆震冲压发动机,开展了总温为860 K、马赫数为2的来流条件下的直连式试验,探讨了燃烧室前缘扩张角(θ=30°,45°,60°,90°)对爆震波传播特性、工况范围及压力分布的影响。结果表明:当燃烧室前缘扩张角为90°时,燃烧模态均为爆燃燃烧;随着扩张角的减小,燃烧模态将会向锯齿波和混合模态(包含单波阶段)转换。当燃烧室前缘扩张角为30°时,旋转爆震的自持工况范围最宽且燃烧室压力最高;同时,随着燃烧室前缘扩张角减小,实现混合模态的当量比下限降低。此外,分析了燃烧模态对来流的影响,发现:锯齿波/混合模态燃烧室内存在的周期性高频压力扰动会使隔离段内的激波串位置前移;混合模态对超声速来流的影响最为显著。     

后勤保障指挥决策系统结构设计研究

军队后勤保障指挥决策系统是高技术局部战争后勤保障的中枢,科学合理构 建系统的结构是提高决策系统质量的关键,针对该系统大范围多领域的分布式特征,引入了 化学抽象机对系统结构进行形式化、规范化描述,可以清楚的反映系统的静态和动态特征, 对后勤"可视化"研究具有一定的指导意义。     

Bureaucracy Does Its Thing: US Performance and the Institutional Dimension of Strategy in Afghanistan

It is not too soon to draw cautionary lessons from the inconclusive results of US performance during more than 11 years of Operation ‘Enduring Freedom’ in Afghanistan. As in Vietnam, fundamental difficulties persist in adapting enduring institutions to the requirements of strategy. At the heart of the matter is tension between the assumptions that underlie counterinsurgency as practiced in Afghanistan and organization of the US Armed Forces, State Department, and Agency for International Development. Knowledge of basic principles and necessary changes is available to answer the question, could the US have done better?     

Global counterinsurgency and US army expansion: the case for recruiting foreign troops

Given the nature of global counterinsurgency operations, the demands of military expansion, and the need for cultural, linguistic, and regional expertise, the United States Army should evaluate the establishment of US-led foreign troop units for its evolving force structure. This article proposes the creation of an American foreign legion based upon the recruitment of US-led, ethnically homogeneous tribal force units to meet the grist mill of counterinsurgency operations. This structured approach would be more beneficial than the current reliance on a de facto American Foreign Legion, represented by private military contractors (PMCs), many of them comprised of foreigners. These PMCs carry a number of oversight, accountability, and legal risks not found in a fully integrated, and US-officered foreign legion. The British Brigade of Gurkhas, the South-West African Police Counter-Insurgency Unit (Koevoet), and the Kit Carson Scouts serve as relevant historical examples where foreign troops were used to supplement national manpower resources.     

Counterinsurgency force ratio: strategic utility or nominal necessity

As a consequence of intervention in Iraq and Afghanistan, force ratio for counterinsurgency (COIN) has come under increased scrutiny. Reduced to its essence, the issue is simply, ‘How many troops does it take to get the job done?’ This answer has been sought by the US military, academia, and think tanks. There have been numerous responses, culminating in several ‘plug-and-play’ equations for minimum force ratios in COIN operations. Due to the impossibility of determining precisely how many insurgent forces there are, it has become common to base force ratios on the population of the country. In the realm of policy, the question above is posed as, ‘How many of our troops does it take to get the job done?’     

基于插件技术的人工免疫智能空间优化平台研究

采用人工智能方法求解空间优化问题已成为当前地理学研究领域的热点之一。研究目的在于通过设计一个开放的、可扩展的人工免疫空间优化模型框架,开发基于插件技术的优化工具软件,丰富空间优化决策支持的方法和技术体系。研究从空间优化问题的基本特点和计算需求出发,定义了面向空间优化问题求解的克隆选择优化模型框架。在此基础上,采用"插件-宿主平台"结构设计了人工免疫智能空间优化平台的总体架构,定义免疫算子插件与空间优化问题应用插件开发机制。实验结果表明,平台的架构和功能设计充分考虑了计算平台的开放性和扩展性,通过平台标准接口的功能扩展可实现对不同类型空间优化问题的求解。空间优化问题研究者或政府决策部门无需关系人工免疫优化方法的具体内涵即可基于本平台完成其具体空间优化决策支持任务。