红外探测系统对某型隐身飞机的作用距离分析

为了估算红外探测系统对某型隐身飞机的作用距离,首先构建该型飞机的简化模型,计算了飞机蒙皮、发动机尾喷口和尾焰等主要红外辐射源的中波红外辐射,然后在考虑辐射的大气衰减的基础上,推导出红外系统对点源目标的作用距离方程,并通过逐步逼近法求解该方程,最后通过算例求出不同气象条件、不同探测方向下的作用距离并对其进行分析。结果表明:红外探测系统探测隐身飞机时,能见度越高,其探测距离越远,并在尾追方向的探测距离大于迎头方向。     

坦克热烟气红外辐射特征数值分析

为了研究坦克热烟气红外辐射特征,针对某型坦克柴油机,利用GT-SUITE建立了仿真计算模型,通过后处理模块模拟得到了排烟管排出的主要辐射气体的摩尔分数。建立了一种能够快速计算热烟气流场和温度场分布的数值计算模型,得到了热烟气温度场和压力场分布结果。提出了一种基于Malkmus模型的非均匀气体光谱透过率的计算方法,得到了热烟气的光谱透过率。在此基础上建立了一种基于红外探测方向离散的热烟气红外辐射计算模型,模拟了某高空飞行器热烟气在2～5μm波带的相对红外辐射强度分布,并与试验数据进行了对比,验证了模型的可靠性。最后模拟计算了坦克热烟气在不同红外探测角度下的红外辐射特征,分析了在红外探测方向上造成红外辐射特征衰减的影响因素。     

液体火箭发动机尾喷焰红外辐射特性

对液体火箭尾部喷焰红外辐射特性进行了仿真计算。利用所扩展建立的液体火箭发动机尾喷焰红外辐射组分的谱带参数数据库和尾喷焰流场数值仿真结果对辐射传输方程进行了数值求解,得到不同观测条件下的光谱辐射亮度。通过与实测数据对比,表明计算方法可行,结果合理。     

装甲车辆动力舱温度场与红外辐射特性

为了对某型装甲车辆动力舱红外辐射特性的影响因素进行研究,采用Fluent软件建立了动力舱冷却空气流动数值计算模型,对动力舱内外流场与结构温度场进行耦合计算,得到了动力舱表面温度场分布和光谱辐射特性,通过与试验数据对比验证了计算方法的可靠性,并在此基础上分析了隔热材料、行驶速度和太阳入射角度等因素对动力舱红外入射特征分布的影响,为下一步提出具有针对性的红外抑制措施提供了理论依据。     

苦心追星天不负，兄妹觅得天王星

<正>弗里德里希·威廉·赫歇尔（1738年11月15日-1822年8月25日）,英国天文学家,恒星天文学的创始人,被誉为“恒星天文学之父”。赫歇尔利用全部业余时间制作望远镜,成为制造望远镜的一代宗师,一生磨制的反射镜面达四百多块,还制造了一架口径1.22米,镜筒长达12米的大型金属反射望远镜。赫歇尔用自己设计的大型反射望远镜发现了天王星及两颗卫星、土星的两颗卫星、太阳的空间运动、太阳的红外辐射;编制了第一个双星和聚星表,出版了星团和星云表,还研究了银河系结构。     

草地的红外辐射计算及热像图仿真

草地地表的温度是仿真其红外热像图的关键,综合考虑太阳辐射、风速、大气温度和空气相对湿度等因素的影响,建立了草地地表的温度计算模型,利用C++语言编程计算出草地地表不同时刻的温度,从而求出红外辐射亮度,并进行红外热像图仿真,仿真结果表明:该模型和方法能够真实地生成草地地表的红外热图像,可广泛应用于红外场景仿真中。     

基于HITRAN数据库坦克排烟热气红外辐射仿真

为了对坦克排烟热气的红外辐射特征进行分析,以坦克某一典型行驶工况为例,分析了不同高度和距离对穿透率的影响。基于最新版的HITRAN中的数据,针对算例给出的参数,利用高分辨率气体红外辐射计算模型计算得到了红外辐射特性。针对坦克某一工况下的排烟,利用高分辨率气体红外辐射计算方法对红外辐射特征进行了模拟计算,并进行了试验测试,最后对计算结果进行了比较。结果表明:大气的衰减作用主要是气体中的CO_2和H_2O分子的吸收作用造成的,在计算排烟热气的红外辐射特征时,需要考虑大气的衰减作用。相较于Curtis-Godson近似谱带模型法,采用高分辨率气体红外辐射计算模型能够更精确地得到光谱辐射亮度。     

基于马尔可夫模型的多点源诱偏系统作战计算问题

针对反辐射武器对多点源诱偏系统的毁伤概率计算问题,提出了基于马尔可夫模型的计算方法。通过分析和推导反辐射武器对单点源的毁伤概率计算方法,引入马尔可夫模型构造马尔可夫链,并在此基础上设计了反辐射武器对多点源诱偏系统的毁伤概率计算方法。进一步,根据作战任务要求,对反辐射武器兵力需求进行计算。同时仿真验证了算法的可行性,结果表明该方法可以较好地计算出反辐射武器对具有多点源的诱偏系统的毁伤概率及兵力需求。     

固定天区小视场星跟踪器两颗星识别方法

研究了在观测天区固定的前提下,小视场星跟踪器视场内只有两颗观测星时的星图模式识别算法。首先简述了研究的必要性;接着简要介绍了实时星图的预处理;随后详细论述了所提出算法的具体步骤;然后说明了导航星表的制定过程。仿真结果表明了算法是有效的,并对仿真试验结果进行了分析;最后给出了结论。     

基于红外辐射计的物体光谱发射率测量方法

发射率是测量红外辐射特性中的重要参数,直接影响测量的精度。在传统的能量法测发射率的基础上进行改进,利用红外辐射计MR170测量目标的光谱辐射亮度并在同一温度相同波段下建立一标准黑体模型,对目标光谱发射率进行求解。实验验证该方法可以获得满意的测量结果。对实验求取的光谱发射率进行误差分析,结果显示误差小于3%。     

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).     

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.     

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.     

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.     

Cyber sheiks and grassroots jihadis: the war in Syria and the devolution of the Bosnian Salafi communities

ABSTRACT

What was the scope of the Bosnian jihadi participation in the war in Syria? Did the Bosnian volunteers tend to join one particular faction? Why did the Bosnian youngsters decide to join the holy war in the Levant? Was this an organized and hierarchical process or was this a grassroots movement? Last, were all the Salafis in Bosnia supportive of this dynamic or did this process cause internal frictions? These are some of the questions that this research will try to answer.     

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.