相对静止气氛下硼颗粒着火过程

针对相对静止气氛下单颗粒硼的着火过程展开了系统研究,考虑硼颗粒周围径向气相流动以及硼颗粒与周围环境间的传热和传质过程,建立了一维硼颗粒着火模型。分析了硼颗粒在实现着火和未能实现着火两种典型情形下的颗粒相、气相组分参数以及颗粒外表面上Stefan流的变化规律,并对其成因展开了分析。研究表明,在实现着火和未能实现着火两种典型情形下,硼颗粒外表面的Stefan流都会经历先由周围空间流向颗粒表面,而后变为由颗粒表面流向周围空间的过程;考虑颗粒外表面处气相Stefan流作用后,硼颗粒的着火延迟时间减少,且压力越大,影响越大。     

基于知识图谱的现代战争研究趋势分析

运用CitespaceⅡ对CNKI文献数据库中共759篇"现代战争"标题论文进行可视化分析,对"现代战争"研究热点及前沿问题进行剖析,对进一步研究"现代战争"具有一定的借鉴价值。     

潜艇舱室封闭条件下火灾烟流特性瞬态分析

将场模拟计算模型引入到潜艇非规则舱室火灾的仿真计算研究中,并在分析潜艇非规则结构舱室几何特性对烟气运动影响的基础上,对不同火源功率条件下、火源处于封闭舱室横向中心位置时的烟流瞬态特性进行了三维分析,得到了轴对称火烟流的体积分数、温度分布和烟气层厚度等特性.最后,与相同条件下的近壁面火烟流特性进行对比,发现舱室横向中心位...     

某岩溶区既有公路隧道突水机理分析

岩溶区既有隧道突水是近年来岩溶区隧道运营过程中出现的新问题.以某跨越地下暗河的既有公路隧道为研究对象,推导岩溶突水处的水压力,并建立颗粒流模型,模拟岩溶突水的形成过程.结果表明,随着岩溶水压力逐渐增大,突水通道形成,说明岩溶水压力是导致岩溶区既有公路隧道突水的重要因素.     

从知识教育入手提升思想政治教育实效的途径

知识教育蕴含思想政治教育的内容和信息,思想政治教育需要以知识教育为载体,提高说服力和感染力。发挥知识教育的思想政治教育功能需要更新教育理念,拓展思想政治教育途径,提高教育工作者的素质。     

狭长密闭空间油气爆炸燃烧数值研究

基于不同控制机理制约不同反应步骤的分步反应燃烧机理,建立了RNG k-ε湍流模型和层流有限速率/涡耗散燃烧模型直接耦合的燃烧模型,采用TVD有限体积法,对充满等体积油气预混气的狭长密闭空间油气爆炸燃烧发生与发展过程进行了数值模拟.为了验证模型的正确性,根据计算结果分析了爆炸流场出现的火焰、压力波和化学反应等特征.所得计...     

基于蓝牙HCI传输层流控模型的构建

根据停-等流控原理构造了一种基于蓝牙HCI UART传输层的流控模型,并对该模型进行了流控效率的分析,提出了最佳流控效率的条件表达式,这对降低HCI UART低速率的瓶颈效能和提高蓝牙数据传输速率具有指导意义,仿真实验结果表明,模型符合流控效率的理论分析。     

行波推进仿生机器鱼

介绍5种常见的鱼类游动模式,分析讨论仿生机器鱼的生物学原型。基于对裸臀鱼属(gymnarchus niloticus)与裸背鳗属(gymnotus carapo)活体鱼的实验研究,建立了长背鳍扭转行波动态曲面的数学模型。依靠长鳍行波实现推进与控制的新型仿生机器鱼,其基本结构是"刚性身体"与"柔性背鳍"的组合,这有利于改善现有摆动式机器鱼的技术性能。裸臀鱼属与裸背鳗属鱼类可作为发展特种机器鱼潜艇的生物学原型,以提高现行水下航行器的效率和机动性能。     

Network disconnection problems in a centralized network

We consider three network disconnection problems in a centralized network where a source node provides service to the other nodes, called demand nodes. In network disconnection problems, each demand node gets a certain benefit when connected to a source node and a network attacker destroys edges to prevent demand nodes from achieving benefits. As destroying edges incurs expenses, an attacker considers the following three different strategies. The first is to maximize the sum of benefits of the disconnected nodes while keeping the total edge destruction cost no more than a given budget. The second is to minimize the total destruction cost needed to make a certain amount of benefits not accomplished. The last is to minimize the ratio of the total destruction cost to the benefits not accomplished. In this paper, we develop exact algorithms to solve the above three problems. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

From first to third stream activities in higher education: the case of the Spanish Defence University centre

The paper adds to the debate on the relationship between military spending and economic growth by analysing the contribution of a military university centre to regional economic development. It goes beyond traditional economic impact studies by including research related effects and integrating “third stream” activities. Conceptualization and categorization are carried out to thoroughly analyse the different dimensions of knowledge and “third stream” actions. The analysis is performed from its settlement and during its first 5 years of existence which allows showing how the strategy of community engagement is developed. The conclusion suggests that, as traditional military roles extend, and military education institutions become higher education institutions, a comprehensive evaluation should be taken into account to enrich the public debate on government spending.