短脉冲激光作用下爆发沸腾的温度及汽泡行为研究

采用短脉冲激光加热浸没在丙酮液池的铂薄膜电阻的方法,以及高压电火花单次放电高速照相技术,在国内首次建立了超急速爆发实验台,达到了微秒级的温度频响和2×106帧/s的高速照相.研究发现,随着激光热流密度增加,试件表面温度快速升高到一饱和值,与过热液体的动力学理论极限温度非常接近.拍摄到了与常规沸腾很不相同的蘑菇云式爆发沸腾照片.试件表面及临近表面的微薄液层内瞬间爆发生成大量大小相当的细小汽泡,汽泡脱离直径远低于经典Fritz公式计算值,上浮速度先快后慢.     

激光推力器液体工质注入系统设计

工质注入系统是液体推进剂激光推力器必不可少的一个组成部分。设计并加工了一套脉冲式液态工质注入系统,解决了工质注入和激光脉冲输出同步的问题;并实现了用相位多普勒粒子分析仪对脉冲式雾化液滴性能参数的测试。     

爆炸沸腾研究进展

分析讨论了液体过热极限、汽泡内压力等爆炸沸腾的重要参数 ,综述了三种主要实验方法 ,提出了有待进一步研究的问题 .     

超急速温升下丙酮液池的温度场计算

通过实验和数值模拟计算 ,研究了瞬时、强热流极端条件下铂薄膜表面覆盖和不覆盖细小金属颗粒时丙酮液体和金属颗粒温度场分布及其变化规律 .确定了温升速率、温度梯度和温度边界层厚度 ,发现了常规沸腾难以解释的现象 ,并指出覆盖金属颗粒后虽然沸腾极为激烈 ,但难以达到极高的温升速率 ,而不覆盖金属颗粒却容易产生爆发沸腾     

矩形腔内相变材料上下加热时接触熔化的研究

本文对矩形腔内相变材料的紧密接触熔化过程进行了分析。矩形容器的上下壁面保持各自的温度对相变材料加热,且相变材料可以有不同的高宽比。应用Nusselt液体边界层理论,本文求得了传热过程的熔化规律与液体边界层厚度,并讨论了熔化温差与高宽比对熔化过程的影响,最后给出结论。     

管道热边界层理论的研究

研究了高粘性液体管道流动的热边界层理论。利用圆柱坐标粘性流运动基本微分方程,提出了管道热边界层方程,推导出边界层中的温度分布以及层流和紊流时热边界层厚度的常微分方程和解析解计算表达式,并通过Matlab编程实例,给出了热边界层厚度解析解与数值解的比较。计算结果表明:1)粘性的影响将使得热边界层的发展加快,随着粘性和流量的增大,其影响将更加显著;2)紊流时热边界层的发展比层流时要慢。     

管道热边界层减阻理论的应用研究

全面研究了高粘性液体管道流动的热边界层减阻理论的应用。利用管道热边界层理论中关于边界层的温度分布及层流、紊流时热边界层厚度的计算表达式,推证了管壁热流量及定性温度的计算表达式,利用指数型的粘温特性方程,采用积分方法推出了管道热边界层流动中层流和紊流摩擦水头损失的计算公式,并给出了设计应用实例。计算结果表明,对于高粘液体短管输送,其流动一般均为边界层入口段,热边界层减阻的最佳范围大致是管长L≤5km,管径D≤200mm。     

利用脉冲激光的片上系统芯片单粒子效应试验

为评估脉冲激光试验对研究SoC(片上系统芯片)单粒子效应的有效性,构建了一个65 nm SoC的脉冲激光试验系统,并进行了试验。提出并采用坐标定位法、有源区聚焦法、ΔZ补偿法等针对大规模倒装焊集成电路的试验方法。对SoC的片上存储器、寄存器文件、RapidIO、DICE触发器等部件进行了脉冲激光试验和分析。结果表明:片上存储器对脉冲激光最为敏感,部件的激光试验与相应的重离子试验现象吻合,利用脉冲激光试验可有效研究纳米工艺下大规模集成电路的单粒子效应。     

传热对水边界层流动的影响

本文评述了壁面传热对水边界层流体流动及其阻力的影响,同时分析了加热减阻的应用及其影响因素。传热不仅对层流流动、层流向湍流的转捩以及湍流流动有明显的影响,而且对流动分离以及由分离引起的空化也有显著影响。以热脉冲加热的主动式加热方式既可用来产生和消除边界层的T-S波,也能用来控制边界层的分离。因此,热控制技术可望在控制边界层转捩和分离,减小流动阻力等方面得到应用。     

基于主动相位控制的脉冲激光相干合成技术

提出并验证了基于随机并行梯度下降(SPGD)算法的主动相位控制脉冲激光相干合成方案.利用低通滤波器滤除脉冲激光光强变化导致的性能评价函数起伏,提取出相位噪声导致的性能评价函数变化,然后将这个低通滤波后的性能评价函数用于SPGD算法的极值寻优过程,从而实现脉冲激光的锁相.对该方案进行了理论分析和数值模拟,并进行了两路脉冲激光相干合成实验.实验结果表明,当系统从闭环到开环时,系统性能评价函数均值提高到开环的1.6倍,干涉条纹长曝光对比度从0提高到0.43.在该方案中,通过增加合成脉冲激光路数,并在各路脉冲激光中引入多级功率放大器,能够得到更高的合成功率输出.     

Putin – the masked nemesis of the strategy of ambiguity

Recent events demonstrate the complex and adaptive approach employed by Russia to reassert influence in Europe. The changing face of Russia’s strategy commenced in 2007 when it launched a crippling cyber-attack against Estonia. This was followed by a large Russian conventional attack against Georgia in 2008, occupying two large areas of the nation. 2014 witnessed the Russian annexation of Crimea where in just a week, Russia seized control of Crimea “without firing a shot.” The annexation of Crimea was rapidly followed by a Russian inspired and led subversive war in eastern Ukraine. The common thread among these diverse Russian operations is its use of ambiguity to confound and confuse decision makers in the West.     

India's counter-insurgency experience: the ‘trust and nurture’ strategy

The Indian Army, a force trained primarily for conventional warfare, has been engaged in internal counter-insurgency operations since the 1950s. Despite such a long innings on a counter-insurgency mode, little attention has been accorded within military circles to doctrinal innovation for waging sub-conventional warfare in India's democratic political context. At best, the Army continues to view counter-insurgency duty as secondary to its primary duty of defending India from external conventional threats. By conceptualizing a counter-insurgency strategy of ‘trust and nurture’, this article aims to fill this critical doctrinal gap in India's military policy. The author argues that a counter-insurgency strategy of ‘trust and nurture’ based on democratic political culture, measured military methods, special counter-insurgency forces, local social and cultural awareness and an integrative nation-building approach will result in positive handling of India's internal security problems. The author utilizes India's counter-insurgency experiences in Assam, Mizoram, Nagaland, Punjab, and Operation ‘Sadhbhavana’ in Jammu and Kashmir as illustrative empirical indicants in order to validate the ‘trust and nurture’ strategy.     

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).     

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.     

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.     

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.     

Reviews

Douglas S. Derrer, We Are All the Target: A Handbook of Terrorism Avoidance and Hostage Survival. Annapolis, MD: US Naval Institute Press, 1992. Pp. x+135, notes, index. $14.95. ISBN 01–55750–150–5

Ian Knight, Zulu: Isandlwana and Rorke's Drift, 22–23 January 1879. London: Windrow & Greene, 1992. Pp.136, 150 illus., incl 8 colour plates, maps, biblio. £35. ISBN 1–872004–23–7

Ian Knight, By the Orders of the Great White Queen: Campaigning in Zululand through the Eyes of the British Soldiers, 1879. London: Greenhill Books and Novato: Presidio Press, 1992. Pp. 272, 17 illus., 1 map. £18.95. ISBN 1–85367–122–3

Manfried Rauchensteiner and Erwin A. Schmidl (eds.), Formen des Krieges: vom Mittelalter zum ‘Low‐intensity’ Conflict’. Graz : Verlag Styria, 1991. Pp.208. DM35. ISBN 3–22–12139–7

Harold J. Kearsley, Maritime Power and the Twenty‐First Century. Dartmouth: Dartmouth Publishing Company, Limited, 1992. Pp.xv + 203, 13 diagrams, index. £32.50. ISBN 1–85521–288–9     

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.