Surface wave propagation in a transversely isotropic elastic layer overlying a liquid saturated porous solid half-space and lying under the uniform layer of liquid     

M. D. Sharma  Rajneesh Kumar  M. L. Gogna 《Pure and Applied Geophysics》1990,133(3):523-539

Dispersion of Rayleigh-type surface wave is studied in a homogeneous transversely isotropic elastic layer overlying a nondissipative liquid-saturated porous solid half-space and lying under a uniform layer of homogeneous liquid. The frequency equation in the form of ninth-order determinant is obtained.Special cases have been deduced by reducing the depth of the layers to zero and by changing the transverse isotropic layer to an isotropic layer. Dispersion curves for the phase velocity have been plotted for a particular model.  相似文献   

地幔对流与岩石层板块的相互耦合及影响──（Ⅰ）球腔中的自由热对流     

叶正仁  滕春凯 《地球物理学报》1995,38(2):174-181

板块运动是地幔对流的主要证据之一．同时，作为地球动力系统中一个相对独立部分，板块自身的存在和运动对地幔内部物质的流动形态有巨大影响．地幔内部的流动由两部分组成：一是由内部非绝热温度差异造成的自由对流解；另一部分是由在地表运动的板块所激发．作为系列工作的第一部分，本文研究球腔中的自由热对流问题．得到了对地幔对流研究有实际意义的下边界为自由、上边界为刚性情况下的临界瑞利数值，不同的瑞利数时球腔内流场和温度场的分布形态等．  相似文献   

Unified Approach to Photon-Counting Microlaser Rangers, Transponders, and Altimeters   总被引：1，自引：0，他引：1  

John J. Degnan 《Surveys in Geophysics》2001,22(5-6):431-447

Unlike current manned systems, NASA's next generation SLR2000 Satellite Laser Ranging (SLR) station is fully autonomous, eye-safe, relatively compact and inexpensive, and, during daytime tracking, operates at signal-to-noise ratios several orders of magnitude below unity. Tiny, passivelyQ-switched microlasers generate ultra-short pulses with output energies on the order of 100 J at few kHz rates to achieve mm-levelranging precision to satellite altitudesof 20,000 km. Special ranging receivers, combined with Poisson statistical analysis of the received photon distribution, enable the system to rapidly and reliably identify and extract the single photon laser echoes from the solar background. The enhanced rate of return, combined with a uniform signal strength, can actually drive down both systematic and random range errors. The new SLR2000 technology has already spawned exciting new applications. Compact microlaser altimeters, capable of mapping the surface of a planet or other celestial body at multikilohertz rates, is one such application, and a high altitude, airborne version is currently being developed under NASA's Instrument Incubator Program. Interplanetary microlaser transponders would be capable of performing decimeter ranging or subnanosecond time transfer to spacecraft throughout the inner Solar System, resulting in improved knowledge of planetary motions and librations and enhanced General Relativity experiments.  相似文献   

瞬态瑞雷面波法在公路工程地质勘察中的应用     

刘长平  郭正言 《安徽地质》2007,17(2):124-127

结合安徽省高速公路建设工程实例,介绍瞬态瑞雷面波勘探技术在公路工程地质勘察中的应用,解决沿线高边坡、深路堑、桥梁、隧道进出口的岩土分层,给出基岩风化分带等工程地质问题,省时、省力,取得了良好的经济效益和环境效益.  相似文献   

Seismic anisotropy of the Slave craton, NW Canada, from joint interpretation of SKS and Rayleigh waves   总被引：2，自引：0，他引：2  

David Snyder  Marianne Bruneton 《Geophysical Journal International》2007,169(1):170-188

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Effect of surface stress on magneto-elastic surface waves in finitely conducting media     

Debi Pada Acharya  Chaitali Maji 《Acta Geophysica》2007,55(4):554-576

This paper deals with the investigation of the effect of surface stress and conductivity on the propagation of surface wave in isotropic, homogeneous, elastic media under the action of a primary magnetic field. Formulation of the general surface wave propagation problem has been made, and the corresponding frequency equation has been derived. Frequency equations for Rayleigh wave, surface shear wave and Stoneley wave have been deduced from that of general surface wave as special cases. The effects of surface stress and magnetic field on the wave velocities and attenuation factors of Rayleigh wave and surface shear wave are shown by numerical calculations and graphs. Some important wave velocity equations, as obtained by other authors, have been deduced as special cases from the wave velocity equation for Stoneley wave. It is found that the combined effect of surface stress and magnetic field modulates the wave velocity ratios and attenuation factors of Rayleigh wave and surface shear wave to a considerable extent.  相似文献   

瑞利散射激光雷达探测平流层和中间层低层大气温度   总被引：4，自引：0，他引：4       下载免费PDF全文

吴永华  胡欢陵  胡顺星  周军  张民 《大气科学》2002,26(1):23-29

介绍了一台瑞利散射激光雷达,它能够探测22～60 km范围内大气温度的垂直分布;比较了两种反演温度的数据处理方法.该激光雷达分别与UARS/HALOE卫星和无线电探空仪观测结果进行了对比,均表现了较好的一致性.同时还模拟分析了平流层低层气溶胶对计算温度的影响.  相似文献   

多道瞬态瑞雷波法在探测煤矿采空区中的应用   总被引：7，自引：0，他引：7  

常锁亮  李贵山等 《中国煤田地质》2002,14(3):70-72

采空区探测是工程建筑和煤矿生产中亟待解决的问题。常规物探方法在对落后的“房—柱”式开采技术造成的面积较小、埋深较浅的采空区进行探测时存在漏报或误报的情况。根据采空区的地球物理特征,探讨多道瞬态瑞雷波技术的探测机理,并通过勘探实例阐述了该方法在浅层煤矿采空区探测中的实用性和有效性。  相似文献   

A hybrid analysis method for linear dynamic soil-structure interaction in time and frequency domain     

丁海平  廖振鹏 《地震学报(英文版)》2001,14(4):440-447

IntroductionThe analysis of dynamic soil-structure interaction for important engineering project is still based on linear model (including equivalent linear model) with complex damping, and traditional frequency domain method (Lysmer, et al, 1975, 1981; DING, et al, 1999). Namely, first calculating frequency domain solution by Fourier transform, and then calculating time domain solution by Fourier inverse transform. The motion equation of a system in frequency domain is usually written as (…  相似文献   

多波勘探技术在地下隐蔽物探测中的应用   总被引：1，自引：1，他引：1  

王超凡  付茂朝  邹桂高  刘金光 《岩土工程技术》2001,(2):119-121

近年来，多波勘探技术已广泛地应用到工程地质的各个领域，它以其快速有效及低廉的工作成本，受到广大工程地质人员的欢迎。在中关村地下粮库和人防工程探测中，采用了高密度地震影像法和多道瞬态瑞雷波法，取得了良好的应用效果，为地下隐蔽物的探测提供了一种新的方案。  相似文献