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101.
复杂面形,结构零件的应用范围越来越广,往往一个零件上既有复杂面形也有微小结构.为了实现复杂面形/结构零件的高效加工,分析了快刀伺服加工方式的特点,设计并研制了音圈电机驱动的快刀伺服系统;基于动力学和电磁学分析,建立了快刀伺服系统的传递函数模型,并对控制方法进行了设计;在此基础上.通过实验对快刀伺服系统进行了性能测试,实验结果表明本文所研制的快刀伺服系统具有较高的运动分辨率、定位精度和工作频响,能够作为快刀伺服加工的进刀装置. 相似文献
102.
慢刀伺服车削技术是一种特殊的创成加工方法,采用C轴、X轴、Z轴联动的方式在极坐标或圆柱坐标内可车削加工自由曲面光学元件。但是由于各种误差因素的影响,使用慢刀伺服技术仅加工一次获得的光学元件可能不满足精度指标。为此需要研究能够进一步提升慢刀伺服车削加工精度的误差补偿技术。Zernike多项式是面形分析与光学分析之间的理想接口工具,因此本文使用Zernike多项式拟合的方法处理慢刀伺服车削加工的误差,并根据慢刀伺服加工技术的特点,建立慢刀伺服车削加工的误差补偿算法。实验结果表明,基于Zernike多项式拟合的慢刀伺服车削加工误差补偿技术可有效地针对加工中产生的特定误差进行补偿,从而提高自由曲面车削加工精度。 相似文献
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Clara Bocchino 《African Security Review》2013,22(2):78-93
Peace parks are a modern means of conflict resolution through nature conservation. The Great Limpopo Peace Park (GLPP), which spans South Africa, Zimbabwe and Mozambique, was established to bring new hope to an area that is infamous for racial and political divisions, civil war and widespread poverty. This paper discusses the impact of international laws governing landmines, the current priority choices of the countries involved, and the situation in the two mine-affected countries: Mozambique and Zimbabwe. Minefields and politics are interrelated, and have an impact at local, national and international level. Using the GLPP as a case study, the article argues that although they have been presented as excellent examples of integrated biodiversity conservation and socio-economic development in developing countries, peace parks will not fulfil their main objective of promoting an image of peace in the aftermath of conflict without addressing landmine contamination. 相似文献
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Simon Anglim 《Small Wars & Insurgencies》2013,24(4):588-608
The period from December 1940 through to the spring of 1941 saw the British Army win a series of rapid and decisive victories over Italian and Vichy French forces in North and East Africa and the Middle East. A key feature of these operations was the extensive British use of fast-moving all-arms mobile formations utilising superior speed and mobility to out-manoeuvre considerably larger Italian formations. A number of reasons have been given for the British Army adopting this mode of warfare, but the paper contends that the best explanation is that they were an organic evolution from methods used by the British Army in ‘small wars’ throughout the early twentieth century, use of mobile ‘frontier columns’ at the operational and tactical level of war being described and recommended by Callwell himself and visible with the Army in practice in operations in India and the Middle East in particular. The inter-war period saw the combination of this model of warfare with post-First World War military technology, notably tanks, close air support and coordination by wireless. Colonial operations in this period also saw some utilisation of what would later be identified as ‘Special Forces’ – also used extensively in the Desert War – the most obvious example being Captain Orde Wingate's Special Night Squads in Palestine in 1938. 相似文献
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Justin O. Smith 《Small Wars & Insurgencies》2013,24(3):448-466
A comprehensive maritime interdiction strategy to attack the insurgent's logistic system was a key element in the defeat of the Tamil Tigers. The campaign of maritime interdiction required the Sri Lankan Navy (SLN) to attack LTTE arms smuggling, sea piracy, and maritime terrorism. The SLN degraded the insurgency's robust maritime logistical network while also devising tactics to engage the maritime insurgents who reacted with swarm and suicide boat tactics. The efforts of the SLN forced the Tamil Tigers to confront the government's final land offensives with diminished resources, thus collapsing a three decades’ old insurgency in a matter of months. 相似文献
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为了适应嵌入式定制微处理器的开发的需要 ,克服现有微处理器仿真工具的某些不足 ,文中介绍了微处理器的仿真验证工具———VCPU的设计和实现方法。同其它微处理器仿真工具相比 ,该工具具有多层次 ,可配置 ,功能全面的特点。利用该工具 ,设计者可在设计早期进行系统集成验证 ,缩短设计周期并减少设计错误。该工具已经在嵌入式微处理器开发过程中得到成功应用 相似文献
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Benjamin Deruelle 《Small Wars & Insurgencies》2014,25(4):754-766
The first conceptual, theoretical treatises about small war (la petite guerre) as special operations appeared only from the middle of the seventeenth century. The term is not used in the eighteenth-century sense of ‘special operations’ in older sources. The supposed absence of any treatment of the subject is surprising considering the obsession with the ‘art of war’ in the Renaissance, but other authors attribute it to a supposed antinomy between chivalric ideals and irregular warfare. But the absence of explicit manuals on the subject is not evidence of absence of advanced reflection on this kind of operations in the Middle Ages and in Early Modern times. We should thus look elsewhere, in other genres, for writings that contain and pass on military knowledge. Epics, romances, educational and military treatises, and memoirs in fact contain elements of a theory of special operations, even though these genres differ from our conception of rationality inherited from the Enlightenment. 相似文献
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Beatrice Heuser 《Small Wars & Insurgencies》2014,25(4):741-753
When twentieth-century authors wrote about ‘partisan warfare’, they usually meant an insurgency or asymmetric military operations conducted against a superior force by small bands of ideologically driven irregular fighters. By contrast, originally (i.e. before the French Revolution) ‘partisan’ in French, English, and German referred only to the leader of a detachment of special forces (party, partie, Parthey, détachement) which the major European powers used to conduct special operations alongside their regular forces. Such special operations were the classic definition of ‘small war’ (petite guerre) in the late seventeenth and in the eighteenth centuries. The Spanish word ‘la guerrilla’, meaning nothing other than ‘small war’, only acquired an association with rebellion with the Spanish War of Independence against Napoleon. Even after this, however, armies throughout the world have continued to employ special forces. In the late nineteenth century, their operations have still been referred to as prosecuting ‘la guerrilla’ or ‘small war’, which existed side by side with, and was often mixed with, ‘people's war’ or popular uprisings against hated regimes. 相似文献