液体火箭发动机控制的新方向

为适应航天飞行任务对推进系统高性能、安全性、可靠性、经济性的需要,在液体火箭发动机控制方面,开展了大量研究工作,出现了一些新方向和新领域。比较集中的研究领域是液体火箭发动机健康(状态) 监控和智能控制。本文介绍液体火箭发动机控制的智能水平演变趋势,健康(状态) 监控系统和智能控制系统的框架、结构,以及与这些系统直接相关的故障模式、传感器技术和故障检测算法。     

关于表达质量之我见

工程设计质量是设计者设计能力和标准化水平高低等方面的综合反映。它主要包括设计质量和表达质量。一项优质的设计,不仅要求设计质量高,还必须具备较高的表达质量。笔者就表达质量的一些问题谈点看法。一、设计质量与表达质量所谓设计质量,主要是指设计先进性,结构简单性,功能良好性,使用可靠性,工艺性、适用性,经济性等指标的优劣。它是工程     

新一代小型火箭首次动力系统试车成功

11月27日,我国新一代小型液体运载火箭在中国航天科技集团,公司六院101所进行首次动力系统试车,并获圆满成功。这标志着我国唯一的火箭动力系统试验台各项性能指标达到国际一流水平,完全满足新一代运载火箭研制需要,为火箭按期首飞提供了重要保证。此次试车是在地面验证火箭动力系统整体可靠性、系统匹配性和设计正确性的唯一手段。     

太空武器系列之四:载人航天器(下)

航天飞机具有在地球和轨道间重复往返、穿梭行动的功能,所以也称之为“太空梭”。航天飞机以其特有的重复使用性、多用途和经济性为人类的航天活动开辟了更宽广的前景。飞行“三剑客”的完美结合航天飞机是火箭、载人飞船和飞机的综合产物,技术上比较先进,也十分复杂。航天飞机的外形比火箭、返回式卫星     

浅谈电子产品在生产中的可靠性保证

随着科学技术的发展,人们对产品质量的要求越来越高,这就伴随着对产品的可靠性要求也越来越高。产品的可靠性是设计和制造出来的,首先是设计出来的。设计决定产品的固有可靠性,而且设计上的不足很难在批量生产和使用阶段来弥补,有的产品甚至由于设计不合理而无法使用。产品设计一经完成,产品固有可靠性就基本确定。如何保证达到产品的固有可靠性,这是生产和制造中所要解决的问题。产品的可靠性是指产品在规定的使用条件下和规定的时间内完成规定功能的能力,它是表征产品质量的一项重要指标,是产品正常工作的基础,产品的功能再强,性能再高,如果使用中总是出故障,这就不算是好产品。本文主要分析电子产品在生产和制造中如何保证达到其固有可靠性水平。     

50000m~3油罐壁厚设计比较与分析

油罐的壁厚设计关系到油罐的经济性和可靠性,如何把握两者的辩证关系对油罐的设计与建设具有十分重要的意义。传统上大型油罐壁厚设计采用的是变点法;以可靠度理论为基础,以可靠性分析模型为核心,提出利用可靠度法求解大型油罐壁厚的新方法。以50 000 m3油罐为例,编程分析并计算以2种方法设计的壁厚。变点法设计的底圈罐壁厚度与圈数无关;以中心点可靠度法求解壁厚,可靠性指标一定时,底圈罐壁厚度同样与圈数无关。探讨可靠度法求解壁厚的可行性,验证变点法设计壁厚的可靠性。     

固体火箭推进技术的发展

本文介绍了固体火箭推进技术的发展趋势;对于战略导弹发动机,主要是提高发动机性能,使导弹小型化,能在汽车上、火车上或飞机上机动发射,对于防空导弹发动机,主要是发展推力可控技术和无烟推进剂,使导弹能对付高速、高机动的目标,并使发射场和导弹本身不被烟雾暴露;对于运载火箭助推器和小型运载火箭发动机,主要是降低成本和提高可靠性。固体火箭推进技术应用于国民经济建设,也是其发展的一个重要方面。     

基于体系结构的C~4ISR系统可靠性指标体系

可靠性分析与设计是C4ISR系统总体设计的重要环节。由于系统的复杂性,传统的可靠性分析方法很难直接应用到C4ISR系统中。随着体系结构技术的不断发展,及其在系统设计中的广泛应用,如何将体系结构技术应用于C4ISR系统可靠性分析与设计成为一个亟待解决的问题。利用体系结构框架对C4ISR系统可靠性指标进行研究。通过分析体系结构产品间关系及其在系统可靠性分析中的作用,提出了作战、连接、功能、系统、系统部件等可靠性指标,并给出相应的可靠性参数。     

一种基于新技术复杂装备的可靠性增长方法

针对新技术复杂装备可靠性增长难的问题,利用可靠性增长理论,结合新技术复杂装备的特点,提出了一种适应于新技术复杂装备可靠性增长的方法。并将其应用于某型无人机系统的可靠性增长,通过2个生产周期达到了预期的可靠性增长目标值。这种方法具有良好的可操作性和经济性,可广泛应用于其他新技术复杂装备的可靠性增长中。     

鱼雷卡箍联接结构模糊可靠性优化设计

针对目前鱼雷卡箍联接结构设计主要采用静强度方法,尚缺乏科学性,将优化技术、可靠性理论和模糊数学有机结构,对鱼雷卡箍联接结构提出基于模糊可靠性的优化设计.以某型鱼雷卡箍联接结构为例,所得结果与常规优化结构进行比较表明,这种方法不但充分考虑了可靠性指标的要求,而且还考虑了有关设计参量所具有的随机性和模糊性,具有一定的理论先进性,对提高鱼雷结构设计水平有着重要意义.     

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.