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161.
本文求得了矩形薄板临界状态时的平衡屈曲挠度微分方程的一般解。可以求解任意边界条件下矩形薄板的临界载荷。以四边自由的正方形板为例求解了四边均匀受压的临界载荷及其屈曲波形。  相似文献   
162.
本文论述了测距可靠性的定义、战术意义和应用概况,分析了测距可靠性的规定条件不明确、试验条件不严格与置信水平比较低的现状。  相似文献   
163.
本文引进矩阵测度概念,讨论了一类带扰动的线性与非线性时变系统的运动稳定性,所得到的渐近稳定性条件改进了文[1]的结果,并去掉了文[4]中要求系统的线性部分为李雅普诺夫可化组的限制条件。  相似文献   
164.
装备结构的复杂性使监测中确定最佳分配点极为困难,本文在最大故障信息量的基础上,提出了故障信息分级的判定原则,用以确定监测点的最佳分布,从而可在最少监测点的情况下,获得最多的装备运行故障信息,为故障诊断提供可靠数据。  相似文献   
165.
本文根据隐蔽锥扫雷达天线的工作原理,从方向性函数出发,分析了接收状态下高频馈电网络中,和差信号的幅相特性与隐蔽锥扫波束交叉点电平的关系,从而对不能自动跟踪的隐蔽锥扫雷达,从天馈系统方面分析了原因,并为设计和部队维修提供了理论根据和有效方法。  相似文献   
166.
Since 9/11, counterinsurgency is back in fashion; the ‘war on terror’ has even been branded a ‘global counterinsurgency’. However the context within which counterinsurgency originally arose is critical to understanding the prospects for its present success; the radically changed environment in which it is currently being conducted casts into considerable doubt the validity of the doctrine's application by many national militaries currently ‘rediscovering’ this school of military thought today. Above all, classical counterinsurgency was a profoundly imperial, state-centric phenomenon; consequently it only rarely faced the thorny issue of sovereignty and legitimacy which bedevils and may doom these same efforts today.  相似文献   
167.
The US Army develops doctrine as a set of fundamental principles that guide its actions in support of national objectives. Recently, those national objectives required stability operations, with increasing scope and frequency. This study examines whether existing US Army doctrine adequately fulfilled its role as a guide to tactics in addressing the challenges that Army forces faced in the first 15 months of the war in Iraq. Field Manual 3-24 Counterinsurgency has remedied many deficiencies, but several remain to be addressed to offer commanders better guidance in the face of the many complex challenges they face in stability operations.  相似文献   
168.
ABSTRACT

Russian political leaders and military strategists are growing increasingly concerned about “strategic conventional weapons”—a broad category that appears to include all non-nuclear, high-precision, standoff weapons—and about long-range, hypersonic weapons, in particular. These concerns are complex and multifaceted (and, in some cases, contradictory), but chief among them are the beliefs that strategic conventional weapons could prove decisive in a major conflict and that Russia is lagging behind in their development. US programs to develop and acquire such weapons—namely, the Conventional Prompt Global Strike program—are of great concern to Russian strategists, who argue both that the United States seeks such weapons for potential use against Russia—its nuclear forces, in particular—and because strategic conventional weapons are more “usable” than nuclear weapons. Asymmetric responses by Russia include increased reliance on tactical nuclear weapons, efforts to enhance the survivability of its nuclear forces, and investments in air and missile defenses. There is also strong—but not completely conclusive evidence—that Russia is responding symmetrically by attempting to develop a long-range, conventionally armed boost-glide weapon.  相似文献   
169.
ABSTRACT

The United States and China are testing boost-glide weapons, long-range strike systems capable of flying at Mach 5 or faster through the upper atmosphere. For the United States, these systems would provide a conventional prompt global strike capability, which, together with US ballistic missile defense programs, Chinese experts regard as a threat to China's ability to conduct nuclear retaliation. This perception is encouraging the Chinese military to modify its nuclear posture in ways that tend to create greater risks for both sides. If China's own boost-glide systems are meant to carry nuclear payloads only, their deployment would not fundamentally alter the current situation between the two states. However, if they were conventionally armed or dual-purpose, or if the United States could not determine the payloads they carried, the deployment of Chinese boost-glide systems could compound problems of strategic stability created by the introduction of ballistic missile defense, antisatellite, and antiship ballistic missile capabilities. If the technical hurdles can be overcome, it may be difficult for the two sides to refrain from these deployments in the absence of strong mutual trust or an established arms-control relationship. New confidence-building measures and expanded mutual transparency are warranted to avoid creating new dangers.  相似文献   
170.
This article seeks to elucidate the concept of nuclear learning. It explores both the “nuclear” and the “learning” aspects of the concept. On the nuclear side, it distinguishes between learning basic facts about nuclear arms and drawing inferences about the larger implications of those facts. On the learning side, it discusses three issues: whether to use the term in a normative or value-neutral manner; the difference between learning that leads to a change in means versus learning that leads to a re-evaluation of ends; and whether learning only takes place at the level of individuals or whether there can also be learning by collective entities. The article argues there is no universal best answer to these questions and that the particular concept of learning that should be employed depends on the goals of the analyst. If the goal is to reduce the chances of nuclear war, however, one type of learning that will be important to consider is whether there is shared, cross-national learning.  相似文献   
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