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The electromagnetic parameters of microwave absorbing materials are important criteria when appraising the properties of absorbents. For reconstruction of parameters which belongs to the inverse scattering problem, the test data in requirement of traditional impedance method are "just enough" and not "redundant" to comprehensively evaluate the electromagnetic properties of materials. A novel optimization approach involving multiple impedance measurements is introduced in this paper to implement automatic measurement for electromagnetic parameters on microwave slot-line. Some results for standard samples and microwave absorbing materials are given. 相似文献
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为了定量地评价试题在反映学生掌握教学基本要求及其知识水平的测试中的作用和意义,本文根据试题的难度、教学要求度、题型以及完成题目所需时间等综合因素提出“试题值”和“等值试卷”这一新概念。讨论它的计算、作用与意义。并对两套“等值”试卷进行了统计试验.试验结果与所提概念吻合。最后,根据所提出的“试题值”概念,提出了由计算机题库生成试卷的原则、方法与流程,可供实用参考。 相似文献
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