坦克动力舱空气流动与传热影响因素的仿真研究

以k-ε两方程湍流模型和非结构化网格为基础,利用FLUENT软件针对某型主战坦克动力舱内的空气流场和温度场进行了三维数值仿真计算与分析,得出了环境温度、压力和坦克行驶速度等因素对动力舱内的空气流动和传热的影响关系.     

Facility location for an extraterrestrial production/distribution system

This paper extends traditional production/distribution system analysis to address raw material, factories, and markets located beyond Earth. It explains the eventual advantages of such operations and discusses likely sites in the solar system. It furnishes a typology for production/distribution systems, assessing the fit of each type to space operations. It briefly reviews the physics of orbits. It develops transportation and inventory cost functions for the simplest case of Hohmann trajectories, and for transportation between circular orbits of similar radii using higher‐energy trajectories. These cost functions are used to derive a model of production/distribution system cost, the minimization of which selects an optimal factory location. The paper suggests potential extensions to this work, and concludes with ideas for location research on the novel reaches of extraterrestrial space. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005.     

一种复合制导的中末交班策略研究

针对复合制导中的中末制导交班问题,设计了一种可同时实现导引头和弹道交班的方案.中制导应用变结构控制理论设计了一种中制导律使导引头在中制导结束时指向目标;交接导引段实现比例系数的过渡,从而保证了弹道的平滑过渡.仿真结果证明了该方案能够适用于远距离制导的复合制导.     

成功移交放火嫌疑案件应注意的几个问题

公安机关消防机构向刑侦部门移交放火嫌疑案件是个难题,结合法规规定和工作实践,指出为提高案件移交率应在第一时间把握放火嫌疑特征、第一时间通知刑侦部门参与、规范协作办案中的关键环节、善于运用法规规定和自身积累的办案经验等方面应注意的问题,提出了共同询问、共同勘验、共同提取和送检物证等见解。     

平面光波导的数值传递函数方法

把数值传递函数方法应用于对平面光波导的分析。本方法从光波导的标量变分关系出发 ,通过状态方程对问题求解计算。文中引入了传递函数无穷单元的概念 ,使得本方法在处理近截止区域的问题时更加合理 ,计算量更小。文后给出了本文方法的应用和算例 ,与多种方法进行了比较 ,表明本文方法在处理折射率均匀分布和渐变分布波导时都有着特有的优势。     

复合材料层合结构的非线性传热分析

基于一阶热层合理论,考虑材料非线性的影响,建立了复合材料层合结构非线性传热分析的热层合理论及其有限元方程.通过数值算例研究了材料非线性对反对称复合材料层合板瞬态温度场的影响.     

磁场环境下黏弹性基体中非局部纳米梁动力学特性分析

根据非局部Euler梁理论建立了外部磁场影响下的黏弹性基体上纳米梁的动力学问题分析模型。通过引入Kelvin黏弹性地基模型和洛伦兹力,得到了纳米梁的振动控制方程。基于Kelvin-Voigt黏弹性模型,给出了黏弹性基体上纳米梁在磁场影响下的固有频率解析解,并就多种典型情况进行了分析。在一般情况下,利用传递函数方法对振动控制方程进行求解,得到了纳米梁固有频率及相应振型的封闭解。以某单壁碳纳米管为例,计算得到了多种边界条件下纳米梁的前三阶固有频率,并详细分析了非局部参数、磁场强度、长细比、阻尼系数及边界条件等因素对纳米梁振动特性的影响情况。结果表明,文中所建的动力学分析模型对研究磁场作用下纳米梁在黏弹性基体上的动力学特性问题准确有效。     

The African Standby Force: The African Union’s tool for the maintenance of peace and security

Declared operationally ready in 2016, the African Standby Force (ASF) has not been deployed in its originally designed form. This is not for the lack of opportunities but rather a demonstration of the power of the Regional Economic Communities/Regional Mechanisms (RECs/RMs) – Africa’s sub-regional security structures – over matters of peace and security. Experience gathered from its short existence suggests that the ASF may never be deployed in its current form. It may instead evolve into a robust framework, adaptable mainly by the RECs/RMs, for addressing varied security challenges. Four things are critical to enhancing the utility of the ASF: the political willingness of the RECs/RMs, the strategic interest of the member states, predictable and sustainable financing, and clarity on the role of the African Capability for Immediate Response to Crisis, the temporary battlegroup that was created to provide the African Union with a rapid response capability, pending the ASF’s operationalization.     

EU Battlegroups: High costs,no benefits

This article reviews the gloomy saga of the EU Battlegroups, focusing on four questions: Where do they come from? What do they look like? What have they been hindered by? And where do they go from here? It builds upon earlier findings in the literature and adds novel insights based on original data. In doing so, the article pays particular attention to the standby nations’ constant calculation of political and financial costs. It argues that recognizing these cost–benefit calculations allows for identifying the most crucial areas to be tackled to make the EU Battlegroups functional. In addition, the article stresses that these considerations play out in a setting wherein the Battlegroups are just one among many policy instruments available for rapid response.     

相变材料下滑过程的接触熔化分析

本文对相变材料在斜面下滑过程中的接触熔化进行了分析。通过理论分析,求得料面保持恒温或变温对相变材料加热并使之匀速下滑时,相变材料的熔化速度、时间及固体瞬时高度。所得结果包含了前人的工作。