一种卫星对接装置空间凸轮机构传动分析验证

针对某新型GEO卫星与其他航天器的对接过程,设计了一种卫星对接装置。该对接装置主要采用空间凸轮机构,首先对其进行详细结构设计,并建立空间凸轮曲线的数学模型,通过理论计算分析空间凸轮机构传动特性。制造样机进行试验验证,通过高速摄影对凸轮机构传动特性进行记录。通过对比表明,试验结果与理论结果高度吻合,验证了空间凸轮曲线数学模型的合理性以及对接装置的可行性。对接装置具有碰撞接触力小、锁紧力大、运动平稳可靠等优点,能够有效地满足GEO卫星对接任务的要求。     

摆动滚子从动件圆柱凸轮的解析设计

本文根据微分几何的包络原理,导出了摆动滚子从动件圆柱凸轮的轮廓曲面方程;在此基础上,讨论了凸轮轮廓的根切条件、滚子与凸轮的接触区域、接触线方向以及凸轮任一圆柱面上实际轮廓曲线的确定;得到了滚子与凸轮任一接触点处的压力角计算公式,并给出了按许用压力角设计的滚子最小接触高度,从而较完整地解决了摆动滚子从动件圆柱凸轮的几何设计问题。     

基于仿射原理的活塞环仿形数控加工系统

本文介绍一种新颖的活塞环非圆轮廓曲线仿形数控加工技术。利用该技术可实现用同一种凸轮加工多种具有不同压力分布曲线的活塞环。当凸轮或刀具磨损后可进行误差补偿加工,提高了机床的“柔性”和精度。同时利用智能决策和模糊控制技术解决抗干扰问题及增强系统的鲁棒性。     

对周转斜盘发动机导槽形式的初步探讨

本文从保证斜盘匀速性的角度导出了凸轮随动机构的理论曲线,该曲线较之被认为有希望的直导槽更能保证斜盘机工作的平稳性,并对它们的优缺点进行了比较。     

变倍望远镜产品标准通过备案

双筒望远镜是四川西南光学仪器厂主导民品之一,自1994年推出8～25×25 M型变倍双筒望远镜以来,该产品在市场上深受国内、外客商的青睐。高倍率变倍双筒望远镜产品,在我国尚属刚起步产品,目前国内还没     

CAD/CAM 中的两种曲线保凸拟合

文中描述了一种保凸参数拟合方法。对于任意给定一个平面开(闭)的凸多边形、可用二次(三次)Bezier曲线段构造了一条C~1二次(C~2三次)的保凸插值样条曲线,并且简略讨论了该方法在CAD/CAM中的应用,如凸轮轮廓曲线的拟合,外形的几何设计等。我们在IBM-PC机上编制了通用的交互式作图软件,只要输入相应的坐标和控制参数,即可快速绘制出C~1二次(C~2三次)的保凸插值样条曲线。     

偏心圆凸轮机构的运动学与动力学分析

按对心与偏置两种情况推导出了偏心圆凸轮机构压力角、位移、速度、加速度表达式,并由此对偏心圆凸轮机构工作过程中的运动学与动力学特性进行了分析。     

活塞凸轮发动机的参数综合

活塞凸轮发动机体积小、功率大,多用于一次性的武器装备中.文中提出了计算空间凸轮机构综合曲率半径的原则方法和提高其接触强度的有效途径,为该种发动机的民用化开辟了广阔的前景.     

圆柱凸轮实际型线分析

本文从分析滚子相对于圆柱凸轮运动的相对速度入手,导出了计算从动件分别为平面移动和摆动的圆柱凸轮实际型线的关系式。     

基于Matlab/Simulink的内燃机凸轮挺柱磨损数值计算的仿真研究

建立了凸轮磨损计算的仿真模型,论证了模型的正确性以及利用Simulink进行凸轮机构的磨损数值计算仿真的有效性,并利用Matlab/Simulink对其进行仿真.仿真结果与实验结果较为吻合.     

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.     

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.