大型复合材料空间刚架缩比模型设计方法

缩比模型试验是获取大型复合材料空间刚架力学特性或响应的一种有效途径,其中一项重要内容是缩比模型设计。以大型复合材料空间刚架为研究对象,阐述已有传统方法的局限性;基于离散相似提出结合有限元方法的方程分析法,利用该方法推导大型复合材料空间刚架静力学响应和动特性的相似关系;利用所提方法设计某复合材料龙骨的1/5缩比模型,并通过试验进行验证。验证结果表明,所提方法和推导的相似关系能够用于指导大型复合材料空间刚架的缩比模型试验。     

Contrasting the Impacts of Combat and Humanitarian Assistance/Disaster Relief Missions on the Mental Health of Military Service Members

Abstract

We study the differential impacts of combat and humanitarian assistance/disaster relief (HA/DR) missions on the mental health of U.S. Marine Corps members. The deployment experiences of any individual Marine are plausibly random conditional on the observable characteristics which are used to assign Marines into units. Leveraging this exogenous variation, we compare the incidence of post-traumatic stress disorder (PTSD) and suicide deaths among Marines who deployed to either Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) or HA/DR missions between 2001 and 2011. We find that the hazard of PTSD is close to eight times higher among Marines returning from OEF/OIF compared to those never deployed, and just 1.33 times higher among those returning from HA/DR (and never participated in OEF/OIF). Those returning from OEF/OIF missions are 1.81 times more likely than those never deployed to die by suicide when they were still active duty, and the hazard increases to almost 3 after they have left the military. In contrast, we find no difference in the hazards of suicide death between those that deployed to only HA/DR missions and non-deployed Marines.     

空袭火力体系规模的数理判断

准确判断敌人空袭火力体系的规模是防空作战争取主动的基础.从解析敌方对我方保卫目标进行空袭兵力需求量的分析入手,通过从空袭某类目标所需出动的作战飞机数判断空袭火力体系的规模;从空袭某类目标所需发射的巡航导弹数判断空袭火力体系的规模,对从定性与定量角度研究空袭火力体系规模具有重要意义.     

高校女教师的心理健康与维护

由于各种原因 ,高校女教师都或多或少受到一些心理问题的困扰 ,帮助她们摆脱心理问题的困扰 ,保持健康的心理状态 ,无论对个人 ,还是对加强师资队伍建设都有深刻的现实意义和深远的历史意义。     

基于灰色聚类和模糊综合评判的装备——装备群健康状态评估

针对目前装备健康状态评估存在的问题,建立了一个基于灰色聚类和模糊综合评判的“装备-装备群”两级评估模型。该模型利用灰色聚类法来评估单个装备的健康状态,将得到的单个装备健康状态的聚类系数向量作为模糊综合评判的隶属度向量,利用模糊综合评判技术来评估装备群的整体健康状态。详细论述了评估模型建立的关键问题：健康状态的分级、评估指标、白化权函数以及权重的确定。最后通过实例分析表明,该模型评估结果合理,可操作性强。     

水下缩比航行体热尾流的红外探测实验研究

根据缩比模型,建立了缩比红外成像实验测试系统,对水下航行体的体积、航行深度、运动速度、尾流排放等进行了缩比设计,设计了多种实验工况,可实现缩比目标模型红外尾流的静态和动态测试,一方面明确红外尾流的可探测性,另一方面掌握红外尾流可探测性的影响因素以及红外尾流的变化规律,为下一步工作奠定基础。     

点状保卫目标的空袭规模预测模型

现代空袭作战已成为结构破坏战,各类政治、经济、军事指挥中心、侦察预警设施,交通枢纽等点状目标已成为敌空袭的首选目标,而如何准确、可靠地预测点状保卫目标的空袭规模是防空作战的首要问题和难点。把点状保卫目标分为立体类目标、平面类目标、地下类目标,根据每类点状目标的特性,构建其相应的空袭规模预测模型,通过算例分析,该模型具有较高的可信度,能为各种辅助决策系统和指挥自动化系统提供决策支持。     

基于种群分类的变尺度免疫克隆选择算法

提出了一种基于种群分类的变尺度免疫克隆选择算法.该算法通过对目标函数进行非线性尺度变换,突出了全局最优解的优势地位;建立记忆子群实现了种群代际进化信息的交换;依据亲和度将抗体分为精英子群、普通子群、劣等子群,并对其分别执行自适应高斯变异、均匀变异和消亡更新等策略,增强了算法的局部和全局搜索能力.引入小生境技术提高了抗体...     

Specialization in defence forces

The choice between balanced and specialized defence forces depends on the technology of defence output (e.g. whether a force scope multiplier is present), the existence of scope and scale economies, the platform customization costs and, of course, the level of defence budgets. Minimum force element levels (thresholds), and scale economies facilitate specialization as opposed to scope economies (e.g. platform‐sharing), scale diseconomies and the force scope multiplier (e.g. defence weakest‐link technology). When a balanced force is not optimal, the option value of a non‐optimally maintained force element must also include the opportunity cost arising from suboptimal force elements. Shrinking defence budgets may produce two surprising phenomena. If some force elements are shut down as a result of thresholds, the surviving ones may increase in platform numbers as well as enjoying closer‐to‐most‐desirable platforms. Furthermore, if heritage force elements are shut down within the budget contraction environment, overall defence capability might rise.     

论动物用于生物武器的新角色

文章通过对动物生物武器概念、特点的介绍,分析了利用基因技术改造动物源病原体,甚至动物本身作为生物武器的方式,提出了我国防御动物为主体的生物恐怖的建议.