排序方式: 共有27条查询结果,搜索用时 15 毫秒
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天津站交通枢纽深基坑降水开挖引起的建筑物沉降分析 总被引:1,自引:1,他引:0
以天津站交通枢纽3标段基坑工程实践为例,利用数值模拟试验,分析施工中降水和开挖对地层沉降造成的影响,指出降水施工引发的沉降占总量的90%,开挖施工的不利影响主要体现在差异沉降上。在实际施工中应高度重视及时封堵隔水帷幕漏水和架设足量的内支撑,结合监测数据,对模拟结果进行分析,肯定盖挖逆作工法在沉降控制上的优势,并提出实际施工的优化方案。 相似文献
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The major constraint on the performance of orthogonal frequency division multiplexing(OFDM) based underwater acoustic(UWA) communication is to keep subcarriers orthogonal.In this paper,Doppler estimation and the respective compensation technique along with various diversity techniques were deliberated for OFDM-based systems best suited for underwater wireless information exchange.In practice,for mobile communication,adjustment and tuning of transducers in order to get spatial diversity is extremely difficult.Considering the relatively low coherence bandwidth in UWA,the frequency diversity design with the Doppler compensation function was elaborated here.The outfield experiments of mobile underwater acoustic communication(UWAC) based on OFDM were carried out with 0.17 bit/(sHz) spectral efficiency.The validity and the dependability of the scheme were also analyzed. 相似文献
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随着我国城市化进程的不断加速,交通问题也逐渐凸显,因此,城市公共交通标识导向系统的建设逐渐成为城市规划和建设的重要方面。本文将从道路标识系统的概念、设计原则和未来发展趋势三个层面探讨我国城市公共交通环境中的标识导向系统设计分析。 相似文献
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基于磁场能量法,给出磁场调制式永磁齿轮(Field Modulated Permanent Magnetic Gear,FMPMG)的齿槽转矩数理模型,进而得出与齿槽转矩相关的结构参数;提出了不同结构参数的优化修型方法,并借助有限元仿真(FEM)验证其有效性;通过仿真结果比对获得FMPMG的最优修型方法,有效减小齿槽转矩,并使FMPMG的动力学特性最优. 相似文献
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