Theoretical design of new bridge-ring insensitive high energy compounds by selected normal Diels-Alder reactions between NH2-substituted oxazoles and NO2/NF2/NHNO2-substituted ethylenes/acetylenes

In this work, NH₂-substituted oxazoles and NO₂/NF₂/NHNO₂-substituted ethylenes/acetylenes were designed and used as dienes and dienophiles, respectively, in order to develop new bridge-ring insensitive high energy compounds through the Diels-Alder reaction between them. The reaction type, reaction feasibility and performance of reaction products were investigated in detail theoretically. The results showed that dienes most possibly react with dienophiles through the HOMO-diene controlled normal Diels-Alder reaction at relatively low energy barrier. Tetranitroethylene could react with the designed dienes much more easily than other dienophiles, and was employed to further design 29 new bridge-ring energetic compounds. Due to high heat of formation, density and oxygen balance, all designed bridge-ring energetic compounds have outstanding detonation performance, 16 of them have higher energy than HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazocine) and 2 others even possess comparative energy with the representative of high energy compounds CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane). The predicted average h₅₀ value of these bridge-ring energetic compounds is 83 cm, showing their low impact sensitivity. The NH₂ groups could obviously impel the proceeding of Diels-Alder reactions, but would slightly decrease the energy and sensitivity performance. In all, the new designed bridge-ring compounds have both high energy and low sensitivity, and may be produced through Diels-Alder reactions at relatively low energy barrier. This paper may be helpful for the theoretical design and experiment synthesis of new advanced insensitive high energy compounds.     

应用多GPU的可压缩湍流并行计算

利用CUDA Fortran语言发展了基于图形处理器(GPU)的计算流体力学可压缩湍流求解器。该求解器基于结构网格有限体积法,空间离散采用AUSMPW+格式,湍流模型为k-ωSST两方程模型,采用MPI实现并行计算。针对最新的GPU架构,讨论了通量计算的优化方法及GPU计算与PCIe数据传输、MPI通信重叠的多GPU并行算法。进行了超声速进气道及空天飞机等算例的数值模拟以验证GPU在大网格量情况下的加速性能。计算结果表明:相对于Intel Xeon E5-2670 CPU单一核心的计算时间,单块NVIDIA GTX Titan Black GPU可获得107~125倍的加速比。利用四块GPU实现了复杂外形1.34亿网格的快速计算,并行效率为91.6%。     

美军飞机易损性实弹测试现状及启示

飞机易损性分析与评估是指对飞机在战斗状态下遭受攻击后受损的难易程度的评价,是衡量飞机战斗性能的重要指标.研究飞机易损性对于飞机高生存力设计和飞机战伤预测评估具有重要意义.本文首先简要介绍了飞机易损性分析的一般方法与流程,收集并整理了美军飞机易损性实弹测试的历史沿革和条件建设现状,同时以F-35整机、F135发动机和C2...     

切实提高领导干部贯彻落实科学发展观的能力

切实提高领导干部贯彻落实科学发展观的能力,重点应抓好四个问题:提高学习竞争能力,坚持靠素质求发展;提高科学决策能力,坚持用制度建强班子;提高依法行政能力,坚持按规章抓工作落实;提高开拓创新能力,坚持创造性地做工作。     

助推滑翔飞行器复合控制系统线性化小偏差运动方程推导与控制系统设计

助推滑翔技术是制导武器实现增加射程、提高机动突防能力的关键技术之一,对飞行器姿态控制有较高的要求,需要设计复合控制方式的姿态控制系统.针对采用空气舵与燃气舵联动控制的飞行器,建立了动力学模型,详细推导了完整的三通道线性化小偏差运动方程,结合典型弹道数据给出了动力系数图像,分析了助推滑翔弹道各飞行段中飞行器的稳定性,在此基础上选取再入段低空飞行特征点进行了姿控系统设计,仿真结果验证了线性化小偏差运动方程的正确性和控制系统的有效性,为进行此类飞行器的稳定性分析与姿态控制系统设计提供了有益的参考.     

伪距定位中的GDOP最小值

讨论了一文计算伪距定位中GDOP最小值时数学上的缺陷和不严格性,指出文献在计算GDOP最小值时没有考虑到对应于钟差的特征值在值域上有限制,从而推导出的最小值不可能得到.对多站布阵时GDOP最小值进行了重新推导,给出不同站点数目时GDOP最小值的通式,并给出GDOP达到最小值时的布阵分布.     

A framework for analysis of national interest: United States policy toward Taiwan

The rise of China in the 21st century has generated a new round of debates on American policy toward Taiwan. Generally speaking, one side suggests that Washington should adjust its Taiwan policy to improve its relations with China, while the other argues against downgrading the relations with Taiwan. Both sides invoke the concept of national interest, but the concept is not unproblematic, and cherry-picking different facts and arguments is far from convincing. This article has two purposes: using the concept of national interest to examine the Taiwan policy, and using this case to illuminate the concept itself. After reviewing the concept, I propose what I call ‘four Ps’ framework to facilitate policy-making and analysis. The framework comprises four factors that help determine which policy is in national interest. They are players (decision makers), preferences (foreign policy goals), prospects (possible outcomes), and power (the capability of achieving goals).     

制导航空子母炸弹高速抛撒分离数值仿真

制导航空子母炸弹在跨音速抛撒子弹药过程中，子弹药与母弹的分离伴随着复杂的流场和激波干扰，该过程中不仅存在着激波与激波的相互碰撞、部分激波的多次反射，而且由于受到多体运动的相互作用，其气流方向也发生变化，形成了变化复杂的压力、速度分布区域。采用数值模拟的方法对制导航空子母炸弹子弹药高速抛撒分离过程进行了数值仿真分析，应用嵌套网格技术，耦合多体动力学方程以及 N－S 方程求解子母炸弹高速分离过程，为工程设计、研究提供理论指导与计算依据。     

新时期加强民用车辆征用工作的几点思考

本文通过对民用车辆征用工作现状和存在问题的分析，从如何明确民用车辆征用需求、掌握民用车辆资源潜力、确定民用车辆征用标准、加强征用演练以及做好征用预案编制工作等方面提出了一些对策建议。     

基于S1000D的IETM创作平台浏览系统研究

浏览子系统是IETM创作平台的重要组成部分,用于显示由创作平台生成的电子技术信息。以IETM研究课题为背景,引入S1000D标准制作IETM,符合IETM的网络化发展方向。在重点分析IETM浏览系统的应用架构模式的基础上,根据系统采用的web架构模型优点,提出了浏览系统框架样式的特点和确定原则,设计了一种浏览系统界面并进行功能验证,取得了良好的效果,以此为我国的IETM研发工作提供参考依据。