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11.
箱式屏蔽效能测试方法及影响因素分析 总被引:1,自引:0,他引:1
为测试强电磁场作用下材料的屏蔽效能,基于屏蔽材料的屏蔽原理,提出一种在GTEM室内置屏蔽箱测试材料屏蔽效能的新方法,构建实验平台,仿真分析屏蔽箱窗口尺寸及测试探头位置对测试结果的影响.实验结果表明:测试窗口大小和测试位置对测试材料的屏蔽效能有影响.其主要影响因素是屏蔽效能的测试频率下限,并确定了0.6m×0.6m窗口的测试频率下限为55MHz,0.3m×0.3m测试窗口的测试频率下限为250MHz. 相似文献
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In many practical manufacturing environments, jobs to be processed can be divided into different families such that a setup is required whenever there is a switch from processing a job of one family to another job of a different family. The time for setup could be sequence independent or sequence dependent. We consider two particular scheduling problems relevant to such situations. In both problems, we are given a set of jobs to be processed on a set of identical parallel machines. The objective of the first problem is to minimize total weighted completion time of jobs, and that of the second problem is to minimize weighted number of tardy jobs. We propose column generation based branch and bound exact solution algorithms for the problems. Computational experiments show that the algorithms are capable of solving both problems of medium size to optimality within reasonable computational time. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 823–840, 2003. 相似文献
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基于对电磁力以及热应力的解析计算公式的推导,运用ANSYS有限元仿真软件对固定电抗器顶底端面情况下的铜箔进行电磁-温度-结构耦合分析,分别得出热应力及所受总应力与应变的分布情况。进一步对电抗器的结构进行优化,综合考虑其结构强度要求与连发温度要求,确定电抗器的最优设计结构,最终通过试验验证出仿真与设计方案真实可信。 相似文献
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用改进的有机金属路线合成了聚对亚苯基硼和聚间亚苯基硼。聚对亚苯基硼的分子量(Mn)为783.66,结构为(1)(可溶于乙醚,苯环为对位取代)和(2)(不溶于乙醚,苯环对位取代);聚间亚苯基硼的Mn为876.56,结构为(1)(可溶于乙醚,苯环间位取代)和(2)(不溶于乙醚,苯环间位取代)。 相似文献
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办有特色期刊 走精品化道路——学报建设发展20年巡礼 总被引:2,自引:0,他引:2
对学报创刊 20年初创调整、改革进取和锻造品牌特色三个阶段进行了回顾;论述了学报在学院教学科研及部队建设中的地位和作用;总结分析了 20年的办刊经验,并从中得到了一些启示。 相似文献
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We consider a make‐to‐order production–distribution system with one supplier and one or more customers. A set of orders with due dates needs to be processed by the supplier and delivered to the customers upon completion. The supplier can process one order at a time without preemption. Each customer is at a distinct location and only orders from the same customer can be batched together for delivery. Each delivery shipment has a capacity limit and incurs a distribution cost. The problem is to find a joint schedule of order processing at the supplier and order delivery from the supplier to the customers that optimizes an objective function involving the maximum delivery tardiness and the total distribution cost. We first study the solvability of various cases of the problem by either providing an efficient algorithm or proving the intractability of the problem. We then develop a fast heuristic for the general problem. We show that the heuristic is asymptotically optimal as the number of orders goes to infinity. We also evaluate the performance of the heuristic computationally by using lower bounds obtained by a column generation approach. Our results indicate that the heuristic is capable of generating near optimal solutions quickly. Finally, we study the value of production–distribution integration by comparing our integrated approach with two sequential approaches where scheduling decisions for order processing are made first, followed by order delivery decisions, with no or only partial integration of the two decisions. We show that in many cases, the integrated approach performs significantly better than the sequential approaches. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005 相似文献
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在UMT-3摩擦磨损试验机上,将Si3N4、CCr15分别与巴氏合金进行了摩擦磨损试验,并利用扫描电镜和X射线能谱仪观察巴氏合金的磨损表面,探讨其磨损机理,为Si3N4-巴氏合金新型陶瓷轴承的实际应用提供理论依据.结果表明:载荷相同时,Si3N4-巴氏合金的平均摩擦因数和磨损率比CCr15-巴氏合金低;随着载荷的增加,Si3N4-巴氏合金的摩擦因数先升后降,波动幅度明显小于CCr15-巴氏合金;载荷为10N时,Si3N4-巴氏合金摩擦因数达到最大值0.13,在15N时达到最小值0.04;摩擦副整体磨损率较低,巴氏合金的磨损率随载荷增大而增大,平均为10-6 mm3/(N-m).在Si3N4-巴氏合金摩擦表面同时存在陶瓷氧化物润滑膜和金属磨屑,共同起到了润滑减摩的作用.Si3N4-巴氏合金作为陶瓷轴承的配合材料,具有比传统轴承更好的摩擦磨损性能,具有广阔的应用前景. 相似文献
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Kevin D. McCranie Marcus Faulkner David French Gregory A. Daddis James Gow Austin Long 《战略研究杂志》2013,36(2):281-293
Patrick Finney (ed.), The Origins of the Second World War. London: Arnold, 1997. Pp.xvi + 461, index. £15.99. ISBN 0–340–67640‐X. Maria Emilia Paz, Strategy, Security, and Spies: Mexico and the US as Allies in World War II. University Park, PA: The Pennsylvania State University Press, 1997. Pp.xii + 264, 10 illus., biblio., index. $55 (cloth); $19.95 (paper). ISBN 0–271–01665–5 and 01666–3. Norman J.W. Goda, Tomorrow the World: Hitler, Northwest Africa and the Path toward America. College Station, Texas A&;M University Press, 1998. Pp.xxvi + 307, 2 maps, biblio., index. $39.95. ISBN 0–89096–807–1. Michael J. Hogan, A Cross of Iron: Harry S. Truman and the Origins of the National Security State, 1945–1954. Cambridge; New York: Cambridge University Press, 1998. Pp.xii + 525, biblio., index. £25; $34.95. ISBN 0–521–64044‐X. Stephen Van Evera, Causes of War: Power and the Roots of Conflict. Ithaca, NY: Cornell University Press, 1999. Pp.viii + 270, index. $35. ISBN 0–801403201–4. Eric Arnett (ed.), Nuclear Weapons and Arms Control in South Asia after the Test Ban, SIPRI Research Report No.14. Oxford: Oxford University Press/Stockholm Int Peace Research Institute, 1998. Pp.viii + 98, index. £12.99. ISBN 0–19–8294115. T.V. Paul, Richard J. Harknett and James J. Wirtz (eds.), The Absolute Weapon Revisited: Nuclear Arms and Emerging International Order. Ann Arbor, Michigan: The University of Michigan Press, 1998. Pp.vi + 312, index. $47.50/£36. ISBN 0–472–10863–8. 相似文献