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601.
This article investigates the little-known plans formulated by Harold Wilson's Labour government to deploy Polaris submarines in the Indo-Pacific region. The scheme was first proposed in 1965 as a response to several problems faced by British policy-makers, including China's acquisition of a nuclear capability, Britain's wish to maintain a meaningful position ‘East of Suez’ at reduced cost, and German pressure for equal treatment within NATO on nuclear matters. Despite extensive high-level discussion, the plans were finally abandoned in mid-1968, as Labour moved more decisively to forsake the world role.  相似文献   
602.
The world is mired in history again, as historical modes of competition return and historical grievances fuel the policies of multiple revisionist actors. If the end of history has ended, then it follows that the time is ripe for an engagement with history’s wisdom. We argue that the making of American statecraft—the deliberate, coordinated use of national power to achieve important objectives—can be significantly enhanced by a better understanding of the past. This essay, which draws on the extensive literature on history and statecraft, U.S. foreign policy, and the author’s own research and experiences, offers a defense of the use of history to improve statecraft, as well as a typology of ten distinct ways in which an understanding of history can improve government policy.  相似文献   
603.
基于云分类器的液体火箭发动机故障诊断方法   总被引:2,自引:0,他引:2       下载免费PDF全文
本文首先将液体火箭发动机故障诊断问题转化为故障特征的模式分类问题,然后针对当前模式分类方法难以处理不确定性信息、属性特征空间的划分过硬等缺陷,结合云模型和云变换研究,提出了一种基于云分类器的液体火箭发动机起动过程故障诊断方法。历次试车数据的验证结果表明,该方法能够及时准确识别发动机起动工作过程中的故障模式。  相似文献   
604.
互感梯度是决定线圈炮加速力的主要因素。本文以螺旋线圈炮为例,建立了计算互感梯度的二维有限元模型,对四种不同属性的封装材料和封装尺寸对互感梯度的影响做出了分析和比较,并给出了不同的封装材料及尺寸下封装的电流密度和磁场分布图。分析表明,互感梯度受到封装材料电导率和磁导率的双重制约。电导率决定了封装中感应涡流的大小;磁导率决定了对磁场的加强程度。减小封装与线圈的间距,导磁材料的磁场加强效果更好,而导电材料的涡流效应也更明显;增加封装的厚度,导磁材料可以更好地增强磁场,但导电材料由于电阻更小涡流效应更明显。为了实现互感梯度的最大化,可以在减小封装与驱动线圈间距并增加封装厚度的情况下使用高磁导率的硅钢片制作封装,硅钢片的厚度应该尽量小从而削弱涡流效应。  相似文献   
605.
The story of the demise of Canada's remarkable CF-105 Arrow jet-fighter interceptor has been told and retold by numerous Canadian writers. As told by most, it is a tragic tale. Canadian Prime Minister John Diefenbaker, in an act as unforgivable as it was incomprehensible, not only destroyed a highly promising all-Canadian state-of-the-art aircraft but ruined all hopes of Canada ever being an important player in the North American defense industry. This article offers a contrasting interpretation — locating the problems leading to the aircraft's cancellation further back in history, and in particular in serious and determinative failures in strategic thinking and analysis by senior Canadian military officials at the time of the Arrow program's birth in 1953.  相似文献   
606.
Historians have noted that both German and French war preparation in 1914 fell victim to the inadequacies of traditional threat-based planning: vulnerability to ‘threat deception’ which caused each to underestimate or mischaracterize the threat; a tendency to ‘mirror-image’ by fitting intelligence into preconceived notions of how the enemy was expected to behave; and ‘group think’ that discouraged a serious consideration of alternative scenarios. This article applies the ‘Balance of Power Paradox’ to explain why, at the dawn of the twentieth century, war planning in both Germany and France was driven by an acute sense of weakness which encouraged each side to fashion highly ‘risk acceptant’ strategies. In particular, he examines why and how French commander-in-chief General Joseph Joffre evolved and rationalized his audacious, and disastrous, Plan XVII to leverage French weaknesses and prevent the stronger German Army from bringing the full weight of its military strength to bear against France. The potential implication of this historical vignette is that leaders, and by extension military planners, of both strong and weak states focus on the constraints faced by their opponents, and assume that they can avoid the limitations of their position, while their opponent cannot.  相似文献   
607.
This article re-examines one of the most infamous incidents in British imperial history: the Amritsar Massacre of 1919, and analyses it within the context of the British Army's minimum force philosophy. The massacre has long been regarded as the most catastrophic failure of minimum force in the history of the British Army. This article reconsiders the arguments over the shooting at Amritsar and the role of Brigadier-General Reginald Dyer, and questions the accepted view that the massacre was such a failure of minimum force. It argues that the circumstances surrounding the massacre must be understood before judging the incident and given these factors it is possible to see it within a minimum force framework.  相似文献   
608.
基于我国自主射频识别空中接口协议GJB 7377.1-2011,提出了一种对时钟偏差不敏感的无源RFID标签编解码算法。该算法充分考虑了时钟频率偏差、计数误差、分频误差等对编解码的影响,推导出了标签正确编解码所需的时钟约束条件,并得到了标签编解码的基本思路和方法。仿真结果表明,提出的编解码算法对标签时钟精度要求较低,只要时钟频率大于1.60 MHz,即可满足要求,大大降低了硬件实现的难度和复杂度,与同类实现方式相比,功耗降低了近50%。  相似文献   
609.
获得载体航行路径上各点地磁场的精确测量值是地磁匹配导航的前提,而载体上各种干扰磁场的存在会引起磁力仪输出的偏差,影响匹配的精度,因此必须对载体干扰磁场进行补偿。在分析载体干扰磁场特性的基础上,提出利用矢量测量值对地磁场总场值进行补偿的方法。该方法首先根据矢量磁力仪的测量模型得到关于载体磁场参数的非线性方程,然后采用非线性参数估计方法估计出精确的载体干扰磁场系数,最后再利用估计结果对测量值进行补偿。通过仿真对该方法的有效性进行研究,并设计了半实物实验对其实用性进行验证。结果表明采用本文提出的方法补偿后地磁场总场值的测量误差在20nT以内,而且该方法参数估计精度高,应用方便,可以有效地对导航载体干扰磁场进行补偿。  相似文献   
610.
多个电源模块并联供电系统,最广泛使用基于最大电流方法的自动均流技术,通过专用的模拟均流总线,传输与模块最大电流成正比的电压信号,各个模块使用该电压信号实现均流.该模拟电压信号很容易受到各种噪声影响,导致均流控制失败.针对该问题,设计了单线数字均流总线,实现最大电流值的数字传输.分析结果表明,设计的单线数字均流总线能够实现模拟均流总线相同的功能,并且具有更强的抗干扰能力.  相似文献   
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