Elastic solutions for stresses in a transversely isotropic half‐space subjected to three‐dimensional buried parabolic rectangular loads     

Cheng‐Der Wang  Jyh‐Jong Liao 《国际地质力学数值与分析法杂志》2002,26(14):1449-1476

In many areas of engineering practice, applied loads are not uniformly distributed but often concentrated towards the centre of a foundation. Thus, loads are more realistically depicted as distributed as linearly varying or as parabola of revolution. Solutions for stresses in a transversely isotropic half‐space caused by concave and convex parabolic loads that act on a rectangle have not been derived. This work proposes analytical solutions for stresses in a transversely isotropic half‐space, induced by three‐dimensional, buried, linearly varying/uniform/parabolic rectangular loads. Load types include an upwardly and a downwardly linearly varying load, a uniform load, a concave and a convex parabolic load, all distributed over a rectangular area. These solutions are obtained by integrating the point load solutions in a Cartesian co‐ordinate system for a transversely isotropic half‐space. The buried depth, the dimensions of the loaded area, the type and degree of material anisotropy and the loading type for transversely isotropic half‐spaces influence the proposed solutions. An illustrative example is presented to elucidate the effect of the dimensions of the loaded area, the type and degree of rock anisotropy, and the type of loading on the vertical stress in the isotropic/transversely isotropic rocks subjected to a linearly varying/uniform/parabolic rectangular load. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

The intermediate-age open cluster NGC 2112     

Giovanni Carraro  Roberto Barbon  Carla S. Boschetti 《Monthly notices of the Royal Astronomical Society》2002,336(1):259-264

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Viscosity of the upper mantle from laboratory creep and anelasticity measurements in peridotite at high pressure and temperature     

Hiroki Sato 《Geophysical Journal International》1991,105(3):587-599

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Ellipsoidal collapse and an improved model for the number and spatial distribution of dark matter haloes     

Ravi K. Sheth  H. J. Mo  Giuseppe Tormen 《Monthly notices of the Royal Astronomical Society》2001,323(1):1-12

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胜利油气区有机包裹体研究及其在油气勘探中的应用     

李荣西  金奎励  廖永胜 《地球科学与环境学报》1997,(4)

应用显微光度术、显微傅立叶红外光谱（Ｍｉｃｒｏ－ＦＴ．ＩＲ）和飞行时间二次离子质谱（ＴＯＦ－ＳＩＭＳ）等原位微分析技术并结合均一温度测量对胜利油气区下第三系沙河街组沙三段中有机包裹体进行了研究。区分出两类有机包裹体，即原生有机包裹体和次生有机包裹体。结果表明两类有机包裹体特征不同，二者物质组成、有机质成分及化学结构、热演化程度等差别也较大。结合地质分析表明原生有机包裹体是沙三段烃源岩生成烃类运移产物，具“自生自储”特点，而次生有机包裹体是沙四段烃源岩生成的烃类二次运移的产物。沙三段是沙河街组油气运移和聚集的主要层位，因而是寻找油气资源的主要目标层。研究表明，有机包裹体是研究油气生成、运移、聚集和演化等成藏系统最有效的手段之一，在油气勘探中有重要的应用意义。  相似文献   

冰雹云雷达回波自动识别系统   总被引：2，自引：0，他引：2  

段勇  贺敬安  谈曙青 《成都信息工程学院学报》2001,16(2):110-116

利用CAPPI资料对立体风暴进行识别，计算并提供出实用的风暴结构参数，采用矩心踊跃法和矩不变量法相结合对单体风暴和混合性风暴回波进行跟踪；最小二第线性外推预报；根据WSD－88D的冰雹算法，在风暴结构基础上本文建立了Windows98操作平台上冰雹识别系统，经单站1年11次强对流天气过程的资料检验，结果表明：雹云识别精度达82％。系统建立了大量人机对话框以方便用户，增加实用性及推广性。  相似文献   

The Fault Block''s Framework in Boli Basin and its Control Over the Deposition     

Cao Chengrun  SHAN Xuanlong  Wang Dongpo  WANG Xianmin  Yao Ping 《世界地质(英文版)》2001,4(1)

Boli basin, between Yishu fracture belt and Dunmi fracture belt, is the biggest Mesozoic coal basin in the east of Heilongjiang Province. Now it is a fault - fold remnant basin. The basin' s shape is generally consistent with the whole distribution of the cover folds, an arc protruding southwards. The basement of the basin can be divided into three fault blocks or structural units. The formation and evoluation of the basin in Mesozoic was determined by the basement fault blocks' displacement features rusulted from by the movement of the edge faults and the main basement faults.  相似文献   

Scattered light models of the dust shell around HD 179821     

T.M. Gledhill  M. Takami 《Monthly notices of the Royal Astronomical Society》2001,328(1):266-276

The dust shell around the evolved star HD 179821 has been detected in scattered light in near-IR imaging polarimetry observations. Here, we subtract the contribution of the unpolarized stellar light to obtain an intrinsic linear polarization of between 30 and 40 per cent in the shell that seems to increase with radial offset from the star. The J - and K -band data are modelled using a scattering code to determine the shell parameters and dust properties. We find that the observations are well described by a spherically-symmetric distribution of dust with an r ⁻² density law, indicating that when mass-loss was occurring, the mass-loss rate was constant. The models predict that the detached nature of a spherically-symmetric, optically-thin dust shell, with a distinct inner boundary, will only be apparent in polarized flux. This is in accordance with the observations of this and other optically-thin circumstellar shells, such as IRAS 17436+5003. By fitting the shell brightness we derive an optical depth to the star that is consistent with V -band observations and that, assuming a distance of 6 kpc, gives an inner-shell radius of     , a dust number density of     at r _in and a dust mass of     . We have explored axisymmetric shell models but conclude that any deviations from spherical symmetry in the shell must be slight, with an equator-to-pole density contrast of less than 2:1. We have not been able to fit simultaneously the high linear polarizations and the small     colour excess of the shell and we attribute this to the unusual scattering properties of the dust. We suggest that the dust grains around HD 179821 either are highly elongated or consist of aggregates of smaller particles.  相似文献   

Analysis of mapping coverage obtained from spacecraft     

Anastassios E. Petropoulos  James M. Longuski 《Celestial Mechanics and Dynamical Astronomy》1994,60(4):431-454

An exact analysis of the coverage obtained by spacecraft using cross-track scanning and nadir-centered conical imaging, under imposed viewing obliqueness and resolution requirements, is presented. In addition to exact expressions for the area acquired and the area acquisition rate, envelope theory is introduced to obtain the boundary of the imaged area. These expressions are relatively compact, allowing rapid machine computation. The effects of the sun phase angle, and of imaging system limitations are also examined. The Galileo mission encounter with Callisto is used as a numerical example, from which certain general conclusions are drawn regarding optimal imaging trajectories.  相似文献   

Rotational broadening and Doppler tomography of the quiescent X-ray nova Centaurus X-4     

M. A. P. Torres  J. Casares  I. G. Martínez-Pais  P. A. Charles 《Monthly notices of the Royal Astronomical Society》2002,334(1):233-240

We present a library of 47 open-cluster integrated spectra, mostly obtained at CASLEO (San Juan, Argentina) in the range  3600 < λ < 7400 Å  , which are made available at CDS. The data are combined with previous spectra to obtain 10 high signal-to-noise ratio basic templates in the young and intermediate-age domains, which are also provided in the library. These Galactic disc templates represent the increased time resolution spectral evolution of a stellar population unit around the Solar metallicity level. The improved signal-to-noise ratio of the present templates with respect to previous template lists, together with their increased time resolution, allowed us to improve the fundamental parameters of some open clusters. The present spectral library will be useful for several astrophysical applications, particularly for population syntheses of star-forming giant galaxies.  相似文献