高温气流内雾滴运动与蒸发特性的理论分析

建立了高温气流内雾滴运动与蒸发的数学模型,对雾滴在高温气流内的运动与蒸发特性进行了理论分析。结果表明,雾滴在高温气流内的运动分为变速段和恒速段,雾滴终端速度取决于气流速度;雾滴粒径越小,追随气流运动的能力越强;雾滴在高温气流内蒸发时,粒径随时间呈指数规律递减。     

水雾雾滴初始位置对喷雾冷却性能的影响

为揭示集水箱内水雾雾滴喷射的初始位置对喷嘴喷雾冷却性能的影响,利用欧拉-拉格朗日方法和离散相模型对发动机排气集水箱内横流喷雾冷却过程进行了三维数值模拟。结果表明:当雾滴进入烟气流场的初始位置距离分隔板小于0.14m时,部分雾滴进入循环涡流区,大量雾滴与分流管管壁反复碰撞,在管壁上形成液膜,使得雾滴蒸发速率降低;当雾滴初始位置位于(0.14,0.23)m时,两相掺混较好,且随着距离的减小,雾滴有效运动行程增加,喷雾冷却效果增强;当雾滴初始位置大于0.23m时,雾滴未在排气室进行螺旋运动而是随气流直接排出集水箱,蒸发时间短,喷雾冷却效果不显著。     

运动液滴蒸发时传热传质过程的理论分析

对突然置入气体环境中的运动液滴的非稳态蒸发过程进行了传热传质过程的理论分析,建立了初始瞬间液滴非稳态蒸发的数学模型,并对模型进行数值求解.结果表明,在一定情况下,运动液滴突然置于气体环境中的初始瞬间,由于气液界面上与周围环境之间存在较大的浓度差,使得液滴在初始瞬间的蒸发速率很大,将会使气液界面的温度有所下降,这一温度的下降范围与液滴的初始温度、环境的初始温度以及液滴的运动速度有关.     

磁镜场约束等离子体的粒子模拟

用PIC粒子模拟的方法描绘具有初始速度分布的等离子体在磁镜场中的运动状态 ,得出等离子体在磁镜场中的运动轨迹图 ,形象表现了磁镜场对等离子体的约束作用 ,表明用PIC粒子模拟方法探索在磁镜场中等离子体运动的物理过程和规律是可行的和有效的 .     

有限气体容积内的液滴传热传质模型与理论分析

用传热传质学基本原理,建立了液滴在有限高温气体容积中的传热传质模型,对液滴在有限高温气体容积内的动态传热传质过程进行了数值求解,分析了有限气体容积和气体初始温度对液滴直径、蒸发速率、蒸发效率的影响。结果表明:在有限气体容积条件下,液滴直径随时间的变化规律与常见的d2规律有明显差异,气体容积越小,液滴蒸发速率越小,蒸发效率越低;气体初始温度越高,液滴蒸发速率越大,蒸发效率越高。     

潜射导弹水中无控段弹道散布影响因素分析

潜射导弹水中无控段弹道散布受诸多因素的影响,设计正交试验比较了这些因素的影响程度。首先建立潜射导弹水下运动方程组,然后从影响散布的4个方面选取了28个因素,并使用正交试验法安排实验,使用Matlab进行初始弹道仿真,最后对仿真结果进行极差分析以确定影响因素的主次关系,进行方差分析以确定影响因素的显著性。结果表明:潜射导弹初始运动参数是引起散布的主要原因,引起滚转角散布的主要因素是浮质心距,对初始无控段弹道优化具有一定参考价值。     

动态液-液旋流分离器油滴运动轨迹模拟

针对动态液-液旋流分离器油、水两相过程,从流体力学基本方程出发,采用雷诺应力模型、QUICK差分格式和SIMPLE算法模拟分析动态液-液旋流分离器内的流场;并以此为基础,采用离散相模型和多相流模型,模拟油、水两相分离过程和油滴运动轨迹.模拟结果表明:油滴粒径决定其在旋流分离器中的运动轨迹、速度及分离特性,大粒径油滴更易于向中心聚集形成油芯,油芯的形状与油滴的大小直接相关;动态液-液旋流分离器的主要分离过程在转筒内完成,油相分离效率随着油滴粒径的增大而提高.     

含灭火添加剂细水雾粒径分布规律

为了研究含灭火添加剂细水雾灭火机理,从添加剂对细水雾粒径分布的影响着手,利用全自动表面张力仪、实时喷雾激光粒度仪对含不同添加剂的细水雾粒径分布进行了研究。结果表明：磷酸二氢铵和尿素使水的表面张力略有增加,氟表面活性剂（Fc-134）和碳氢表面活性剂（APG）以及由4种添加剂组成的复合添加剂使水的表面张力大幅降低;磷酸二氢铵使粒径为2.09～26.23μm的雾滴数略有减少,粒径为31.06～462.33μm的雾滴数略有增加;氟表面活性剂（Fc-134）使粒径为8.05～22.16μm的雾滴数增加,粒径为22.17～278.64μm的雾滴数减少,粒径为278.65～1075.09μm的雾滴完全消失;碳氢表面活性剂（APG）使粒径为2.09～31.06μm的雾滴数减少,粒径为36.77～141.86μm的雾滴数增加;而复合添加剂使粒径为2.09～31.06μm的雾滴数减少,粒径为36.77～198.82μm的雾滴数增加。     

核磁共振研究溶胀AB-交联聚合物中的分子运动

测定了溶胀的PPU/PSAB 交联聚合物中链段和侧基的13CT1和NOE ,用VJGM模型和三等价位跃迁内旋转、扩散内旋转以及等价、不等价两位置跃迁内旋转模型分析了其中的主链链段运动和侧基内旋转运动 ,求出了主链和侧基的运动相关时间、扩散系数和活化能等参数 .结果表明PS含量对PPU运动的影响极小 ,PS主链运动活化能与PPU含量存在线性关系 .丙烯酸与苯乙烯共聚对PPU的运动几乎无影响     

人工造雾成雾过程微物理性能分析

通过对人造雾宏观性能和微物理性能变化过程的观测与分析,研究了人造雾成雾过程和成雾机理,并结合对云雾生长理论的分析比较了实际雾滴粒径分布范围、生长时间等与理论计算结果的异同。结果显示人造雾的雾滴粒径和生长时间与理论计算结果基本相符,但其具体的生长过程与理论过程有所差别;人造雾与天然雾相比,雾滴数密度稍大,但雾滴粒径和含水量稍小,雾滴谱分布特点有所不同。     

Helping hands: civil–military cooperation and Italy's military operation abroad

In the Post-Bipolar Era the growing complexity of the military operations requires a new approach for the resolution of international crises. Since the end of the Cold War, peace support operations (PSO) have become the mainstay and principal occupation of most Western armies. At the same time, Italy has been one of the most important actors in such an area. The article focuses on the cooperation between military and civil components (a process called CIMIC) as a key variable in the Italian PSOs. We will analyse in detail the main lessons learned from past military interventions as well as the general context in which new tendencies are taking place. The maintaining of a minimum security frame becomes essential to fulfil activities ‘collateral’ to the mission: reconstructing services and infrastructure, food distribution, water and medication, law and order, de-mining, training of local forces, and supporting local institutions. These are the main tasks to obtain thrust and support from the population.     

Terrorism,insurgency, kidnapping,and security in Africa's energy sector

Energy continues to serve as the bedrock of modern economies and the main driver of modern society. For Africa, the production and supply of energy resources such as crude oil, natural gas, uranium, coal, biomass, biofuels and other renewables are an important source of employment, rents, taxes, royalties and profits. This sector brings in several tens of billions of dollars of revenue annually. The production and delivery of such resources, however, depend on critical infrastructures such as pipelines, refineries, processing plants, terminals, rigs, electrical energy pylons, substations, pump stations, vessels, and tankers. These infrastructures have been attacked by terrorists, insurgents, vandals and saboteurs, all of whom see them as targets against which to register their grievances and extract concessions from the state. This paper is a chronological account of some of the documented incidents of terrorism, insurgency, kidnapping, destruction, sabotage, and human casualties suffered in the oil and gas sectors in Africa between 1999 and 2012. It is based on data extracted from the databases of the RAND Database of World Terrorism Incidents and the University of Maryland's Global Terrorism Database (GTD).     

A1 Qaeda and the radical Islamic challenge to western strategy

The September 11 global crisis prompted by the attacks on the World Trade Center and the Pentagon raises major questions concerning the nature and trajectory of terrorism in the post-Cold War global order. Hitherto, terrorism has been largely debated by analysts at the level of nation states. Terrorist and insurgent movements have also been largely anchored in nationalist and ethnic power bases even when they have sought to mobilise a transnational ideological appeal on religious or class grounds. There have been a few exceptions to this pattern such as the alliance between the German Baader-Meinhof group and the Japanese Red Army Faction, but even such international alliances as this did not, until at least the 1980s, presage anything like a global terrorist network necessitating a global strategic response. This study examines terrorism and global strategic responses.     

Tacit support for terrorism: The rapprochement between the USSR and Palestinian guerrilla organizations following the 1967 war

This article demonstrates the inconsistent and wavering Soviet attitude towards national liberation movements in general and the Palestinian organizations in particular. Until the late 1960s, the Soviets viewed these organizations with suspicion, hesitating to engage in political dialogue with them. However, in the 1970s, political and military events in the region, as well as modifications in the Kremlin's Cold War strategies, led to a general shift towards the Middle East in Soviet foreign policy. Soviet leaders showed increased willingness to provide certain Palestinian organizations with arms with which to conduct terrorist activities against Israeli, pro-Israeli, Jewish and Western targets. The article explores the complex relations between Palestinian organizations and the USSR in the field of international terror. The study also exposes and analyzes the nature and content of Soviet–Palestinian arms dialogues and transactions. It provides clear evidence that Soviet policymakers and other luminaries were fully informed of, and sometimes directly involved in, these transactions and dialogues at the highest levels.     

The UK,interrogation and Iraq, 2003–2008

The UK’s interrogation operations during the conflict in Iraq (2003–2008) are often portrayed by the media as involving significant amounts of mistreatment. This article demonstrates that these practices are not necessarily representative of the UK’s interrogation operations across this conflict. In doing so it contributes to the limited literature on the practice of interrogation and on the UK’s combat operations in Iraq. The UK’s interrogation capability, and therefore its intelligence-gathering capability, is shown to have rested primarily with the military’s Joint Forward Interrogation Team (JFIT). The JFIT suffered from limitations to the number, training and experience of its interrogators and interpreters. It is argued that maintaining a permanent, higher level of preparedness for interrogation by the British armed forces is desirable.     

Remembering and forgetting Mirambo: Histories of war in modern Africa

ABSTRACT

While the study of organised violence is considered essential to understanding the history of the West, and accordingly imbued with various layers of meaning and remembrance, war is widely regarded as inimical to the modern nation in Africa and stable development more broadly. Using examples drawn from primarily from East Africa, this paper considers the ways in which warfare in the deeper (‘precolonial’) past has been framed and envisioned in recent decades, in particular by governments whose own roots lie in revolutionary armed struggle and who began life as guerrilla movements. While in some cases particular elements of the deeper past were indeed mobilised in pursuit of contemporary political goals, in many other scenarios histories of precolonial violence were beheld as problematic and unworthy of remembrance. This paper highlights the paradox and ambiguity which has attended the memory of key aspects of Africa’s deeper past.     

Helping hands: external support for the KNU insurgency in Burma

This article analyses to what extent the Burmese KNU insurgency made use of external support from states, refugees, and diasporas. Based on extensive fieldwork it is concluded that support from neighbouring states and refugees has for years kept the Karen rebellion alive. Western countries perceived forms of resistance to the illegitimate Burmese regime as just and have therefore played a crucial role in the continuation of conflict in Karen State. It is important that policymakers and donors as well as executing organizations continue to reflect critically on the way they exercise their work.     

SIM—LISP:一个通信网络管理专家系统外壳的设计与实现

本文介绍了笔者为开发名为OONMES的网络管理专家系统所实现的一个简单专家系统工具SIM-LISP。SIM-LISP是一个用C/C++语言来实现的模拟LISP语言的可调用函数集,它短小精巧,速度快,可以完成针对网管专家系统的事实或规则知识的表示、匹配、合一和推理等基本操作,并有与知识对象的连接功能,是网管专家系统内核实现的支撑环境。     

Al Qaida on the US invasion of Afghanistan in their own words

This article consists of selected translations from captured interviews and dairies of Al Qaida members. The time period covered is from mid-2001 to early 2002 and concerns their operations in Afghanistan. The material clearly conveys a range of emotion, from confident to despondent, as well as efforts to contest the US actions. The first several pages give the reader context and some possible “lessons learned,” but the story(ies) are best told by the Al Qaida members themselves. All names are pseudonyms.     

基于GTST-DMLD-ESD的装备RMS建模仿真

装备的RMS是装备的重要设计参数,是影响战备完好和保障能力的关键因素.引入GTST-DMLD作为主要建模工具,建立起装备系统的RMS描述模型,以ESD为补充和扩展,对维修过程进行建模.并以GTST-DMLD-ESD模型作为装备RMS仿真的核心,对装备RMS仿真模型的总体框架进行了研究,并对各模块进行了较为详细的探讨.