共查询到10条相似文献,搜索用时 62 毫秒
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ITU—R建议中几项电波传播技术模式 总被引:1,自引:0,他引:1
章介绍ITU-R建议中五项电波传播技术模式的研究情况。它包括对流层散射传输损耗统计预测方法、海事卫星移动通信海面反射衰落预测方法、电离层闪烁衰落换算方法、大气衰减简易预测方法和陆地移动通信场强预测方法。 相似文献
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以往文献中的Tiebout模型假设不考虑对就业机会的限制,所有人都靠股息来维持生活,即社区居民收入具有同质性,但此假设的限制性过强而不具有现实性。在该模型的基础上,放松这条假设,将其改为社区居民收入具有异质性,在此条件下研究地方公共产品的供给问题,建立了一个Tiebout的改进模型,并与原模型进行了比较,得出了社区达到均衡的条件以及达到均衡后社区的结构特征上有别于Tiebout原模型的结论。 相似文献
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Heat conduction at low temperatures shows several effects that cannot be described by the Fourier law. In this paper, the performance of various theories is compared in case of wave-like and ballistic propagation of heat pulses in NaF. 相似文献
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Technical Physics Letters - An experimental investigation of the multipath propagation of ultrawideband (UWB) microwave chaotic radio pulses in a wireless channel has been carried out. Based on the... 相似文献
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生物法净化几种气态污染物的研究 总被引:5,自引:0,他引:5
应用生物膜填料塔对工业废气中常见的甲苯、苯乙烯、甲醛、CS2,SO2,H2S,NOx等7种气态污染
物进行净化实验,结果表明,采用专用菌种挂膜制作的生物膜填料塔对该7种气态污染物均有生物净化作用,
但其对SO2,H2S,NOx等3种无机污染物的生物净化作用(生化去除量可达90~150mg桙L·h)明显优于对甲苯、
苯乙烯、甲醛、二硫化碳等4种有机污染物的净化作用(生化去除量除对甲苯的可达100mg桙L·h外,均低于30
mg桙L·h)。研究确定了净化各污染物的适宜操作条件,并对7个专用菌种进行了鉴定。 相似文献
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Abdelwahed S. Karsai G. Mahadevan N. Ofsthun S.C. 《IEEE transactions on instrumentation and measurement》2009,58(2):240-247
Timed failure propagation graphs (TFPGs) are causal models that capture the temporal aspects of failure propagation in typical engineering systems. In this paper, we present several practical modeling and reasoning considerations that have been addressed based on experience with complex real-time vehicle subsystems. These include handling intermittent faults, reasoning over dynamically commanded test sequences, dealing with the constraints of limited computational resources, and providing automated model verification. We finally present a vehicle subsystem case study. 相似文献