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1.
机械构件的不同的失效模式之间具有一定的相关性,而且随机载荷作用次数对机械构件的可靠性有一定程度的影响。因此对机械构件进行可靠性灵敏度分析时,需要充分考虑其不同失效模式和载荷作用次数的影响。通过运用顺序统计量理论考虑载荷多次作用以及多种失效模式条件下机械构件可靠性及可靠性灵敏度的变化规律,运用随机摄动理论和四阶矩技术,建立一种考虑载荷作用次数的多失效模式机械构件可靠性灵敏度分析数值方法的应力强度干涉模型。在随机变量前四阶矩已知的情况下,结合灵敏度分析的梯度算法,推导出关于随机变量均值和方差的灵敏度计算公式。以某履带车辆底盘扭力轴为例进行计算,得到其可靠度随载荷作用次数、随机变量均值和方差而改变的可靠性灵敏度变化曲线,为扭力轴的可靠性优化提供一定的理论依据。研究成果可以推广到相关机械可靠性灵敏度设计和结构优化领域,具有非常重要的实用意义。  相似文献   
2.
在进行消防技能教学时,动作示范法是在教学中常采用的一种行之有效的方法,它能真实、具体、生动、形象的反映出动作技术结构,帮助学生了解动作过程、要领和完成方法及时空关系等,根据消防技能教学的特点和规律,对动作示范法在消防技能教学中运用进行了分析。  相似文献   
3.
Abstract

In Operation Iraqi Freedom, which ended in August 2010, nearly 3500 hostile deaths occurred among US military personnel and 32,000 more were wounded in action (WIA). More than 1800 hostile deaths occurred during Operation Enduring Freedom (in and around Afghanistan) through 2014 and about 20,000 were WIA. A larger proportion of wounded personnel survived in Iraq and Afghanistan than during the Vietnam War, but the increased survival rates were not as high as some studies have asserted. The survival rates were 90.2% in Iraq and 91.6% in Afghanistan, compared with 86.5% in Vietnam. The casualty rates varied between the conflicts in Iraq and Afghanistan and before, during, and after the respective surges. Amputation rates are difficult to measure consistently, but I estimate that 2.6% of all WIA and 9.0% of medically evacuated WIA from the Iraq and Afghanistan theaters combined resulted in the major loss of a limb. Elevated non-hostile death rates (including deaths due to accidents, illnesses, homicides, or suicides) resulted in about 220 more deaths in Iraq and about 200 more deaths in Afghanistan than would have been expected in peacetime among populations of the size deployed to those two conflicts.  相似文献   
4.
汪坤林  潘晓刚 《国防科技》2017,38(4):122-125
文章介绍了态势差的概念内涵,分析了在设计联合作战行动时为什么要分析态势差,阐述了如何分析态势差。态势差分析是工程化作战筹划的一个环节,研究态势差分析机理,能为作战行动设计提供有力支撑,提高作战筹划效率。  相似文献   
5.
抗击临近空间高超声速飞行器对策研究   总被引:1,自引:0,他引:1  
在未来的空袭作战中,临近空间高超声速飞行器具有其他武器所不可比拟的优势,它必将成为一种新威胁。首先分析了该飞行器的卓越性能,简述了它的军事用途,其次论述了它的出现对防空反导体系所产生的影响,最后针对这种新型的威胁,提出了几点应对措施。  相似文献   
6.
The efforts of President Barack Obama and his administration to restore the United States as a driving force of multilateral arms control and nonproliferation negotiations are commendable, yet the lack of progress on such issues over the last eight years has ensured that U.S. policy has not kept pace with changes in the geostrategic environment and the evolving security agenda. Meanwhile, an alternative agenda has been articulated by non-Western countries. This article focuses on the arms control perspectives of Non-Aligned Movement states and others that have begun to embrace the idea of “disarmament as humanitarian action.” It explores this idea in the context of recent initiatives and argues that if the Obama administration wants to make progress on its arms control and nonproliferation priorities, it should consider a multifaceted approach that incorporates this emerging alternative agenda.  相似文献   
7.
This paper examines the rationale and centrality of private military and security companies (PMSCs) in humanitarian assistance operations in Sudan, asking why PMSCs are involved in humanitarian assistance operations in Sudan and what the principles underlying their activities are. To answer this question, the paper draws attention to the link between humanitarian crises and PMSC interventions. Where there is no meaningful alternative intervention, undergirded by humanitarian concerns that are also profit driven, PMSCs come in to provide the needed services. The protracted and complicated internal armed conflicts in Sudan, which have lasted for over two decades, have produced as many as 4,8 million internally displaced persons (IDPs) – the single largest number in the world. The kind of humanitarian assistance operations provided by PMSCs in Sudan have become critical to the provision of much-needed services which were inadequately provided by governmental authorities at both unilateral and multilateral levels. This paper argues that the humanitarian crises in Sudan created a regime that permits humanitarian assistance operations by both state and non-state actors.  相似文献   
8.
This article outlines the widespread needs of South African military veterans and the possible consequences if the promises made in the recent Military Veterans Act are not met. The first part of the article defines who generally qualifies as a military veteran, how they are typically compensated in various countries with specific reference to neighbouring southern African countries, and what the consequences are when veterans become disenchanted with the state. The second part focuses on South Africa and the recent debates on military veterans and their entitlements. With reference to the findings of a qualitative study conducted among military veterans, parliamentary debates and media reports, an assessment is made of the demands and affordability of promised benefits and the consequences should the state not deliver. The conclusion is reached that heightened expectations are presently frustrated by slow roll-outs, and this is likely to increase the possibility of protest action. This has now the potential to create further tension within the ruling party and civil society, as the pressure on public finances mounts and demands become unsustainable. The effect this may have on political stability will depend on how the government manages this issue.  相似文献   
9.
Armed conflict on the African continent has witnessed increasing recruitment of child soldiers, often at the hands of non-state armed groups. Unfortunately this practice continues unabated in the face of legal obligations prohibiting the recruitment of child soldiers under international humanitarian law, and international and regional human rights law. While international condemnation of the practice has led to attempts to increase the minimum age for recruitment to 18, a disjuncture persists between the legal obligations states sign up to, and the actual enforcement of these prohibitions at a domestic level.

International criminal law jurisprudence emanating from the Special Court for Sierra Leone and the International Criminal Court is being monitored closely, as these courts seek to enforce the prohibition in all armed conflicts, and against both state actors and non-state armed groups. International humanitarian law only protects child soldiers who have been unlawfully recruited. In this piece, the authors take a closer look at what amounts to unlawful recruitment in light of customary international humanitarian law, since this body of law also binds non-state actors, even without further criminalising legislation at a domestic level. Moreover, the article briefly explores whether a child can ever void this protected status by volunteering to participate directly in hostilities.  相似文献   
10.
This analytical article asks the question: to what degree did the media contribute to the Rwandan genocide and what might have been done about it? In examining the historical development of mass media in Rwanda, this paper argues that while hate media clearly contributed to the dynamics that led to genocide, its role should not be overstated. While it is commonly believed that hate media was a major cause of the genocide, instead it was a part of a larger social process. The use of violent discourse was at least as important as, for example, the availability of weapons in carrying out the genocide. Put another way, violent discourse was necessary but not sufficient by itself to cause the genocide of 1994. In arguing this thesis, Rwandan history is examined to demonstrate the processes of communication in the formation of destructive attitudes and behaviour. Next, analysis of the methods and content of propaganda campaigns is discussed. Finally, an overview of the requirements and organizations for third parties to conduct international communication interventions is presented in the last section.  相似文献   
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