砂土液化的尺度与概率     

刘颖  李大华 《地震研究》1993,16(2):193-198

本文以液化安全间距及安全系数为随机变量进行了可靠性分析,给出了衡量砂土液化严重程度的尺度及相应的液化概率,并提出了对砂土液化严重程度进行分级的建议。  相似文献   

Scale Dependencies of Vegetation and Topography in a Mountainous Environment of Montana   总被引：2，自引：2，他引：2  

Ling Bian  Stephen J. Walsh 《The Professional geographer》1993,45(1):1-11

This research examines the effects of spatial scale on estimating the relationship between vegetation biomass and topography within a portion of Glacier National Park, Montana. The Reflectance/Absorptance vegetation index, developed from processed Landsat Thematic Mapper digital data, is related to three topographic variables obtained through processed Digital Elevation Models: elevation, slope angle, and slope aspect. R² values between the vegetation index and the topographic variables are obtained from regression analyses at a series of aggregated spatial scales. The effective range of spatial scales within which the two sets of variables are spatially dependent and the degree of the spatial dependencies are characterized through semivariance and fractal analyses.  相似文献   

Highly Localized Vernacular Regionalization in the Allentown-Bethlehem Area,PA-NJ*     

Douglas E. Heath 《The Professional geographer》1993,45(3):251-263

Yi-Fu Tuan's cognitive theory of the construction of place suggests the need for a higher level of resolution in research on American local vernacular regions. A survey-based case study of the Allentown-Bethlehem area demonstrates that municipal data can substantially refine an existing county-based delimitation by revealing previously undocumented regions and subregions, areas with mixed regional identity, and areas lacking regional identity. The resulting delimitations of subcounty vernacular regions are sufficiently precise to disclose a striking correspondence with area school districts.  相似文献   

Band-limited heterogeneous fractal structure of earthquakes and acoustic-emission events     

Xinglin Lei  Osamu Nishizawa  Kinichiro Kusunose 《Geophysical Journal International》1993,115(1):79-84

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广义扰动位公式     

申文斌  晁定波  金标仁 《武汉大学学报(信息科学版)》1994,(4)

在对δＭ和Ｕ０不作限制的条件下，给出了整个地球外部空间的广义扰动位公式，而ＳｔｏｋｅｓＰｉｚｚｅｔｔｉ公式以及ＳＰＨＭ公式均为其特例．  相似文献   

一个正压和斜压不稳定的充要条件   总被引：1，自引：0，他引：1  

陆维松 《南京气象学院学报》1994,17(2):135-140

提出一个新的李雅普诺夫函数，首次得到了正压和斜压不稳定的充要条件，大大改善了热知的Ｒａｙｌｅｉｇｈ－郭晓岚定理和Ｆｊｏｒｔｏｆｔ定理，解决了Ｒａｙｌｅｉｇｈ（１８８０）提出的无粘切变流正压稳定性问题。  相似文献   

Stochastic space transforms in subsurface hydrology — Part 2: Generalized spectral decompositions and plancherel representations     

G. Christakos  D. T. Hristopulos 《Stochastic Environmental Research and Risk Assessment (SERRA)》1994,8(2):117-138

In earlier publications, certain applications of space transformation operators in subsurface hydrology were considered. These operators reduce the original multi-dimensional problem to the one-dimensional space, and can be used to study stochastic partial differential equations governing groundwater flow and solute transport processes. In the present work we discuss developments in the theoretical formulation of flow models with space-dependent coefficients in terms of space transformations. The formulation is based on stochastic Radon operator representations of generalized functions. A generalized spectral decomposition of the flow parameters is introduced, which leads to analytically tractable expressions of the space transformed flow equation. A Plancherel representation of the space transformation product of the head potential and the log-conductivity is also obtained. A test problem is first considered in detail and the solutions obtained by means of the proposed approach are compared with the exact solutions obtained by standard partial differential equation methods. Then, solutions of three-dimensional groundwater flow are derived starting from solutions of a one-dimensional model along various directions in space. A step-by-step numerical formulation of the approach to the flow problem is also discussed, which is useful for practical applications. Finally, the space transformation solutions are compared with local solutions obtained by means of series expansions of the log-conductivity gradient.  相似文献   

安徽庐江龙桥铁矿含矿地层的古地磁学研究          下载免费PDF全文

阎桂林  魏燕平 《地球科学》1994,19(5):695-700

通过对安徽庐江龙桥铁矿ＺＫ１００４孔（深６１７ｍ）１３２个古地磁标本的研究，认为该矿区赋矿地层的时代应属晚侏罗世（１３６－１４７Ｍａ）；其上覆火山岩地层应旭属下白垩统；将龙门院组、砖桥组划归下白垩统较为合理。  相似文献   

地质流体与构造运动   总被引：6，自引：1，他引：6  

陶于祥  谢鸿森 《地球科学进展》1994,9(3):24-29

运用大量的研究成果，综述了地质流体与岩石应变、微观裂隙开合，宏观（中等规模）褶皱、断裂的相互关系。并指出今后尚须加强中型构造运动过程中流体动力学基础理论、差异应力作用下水岩地球化学及其模拟实验、流体与灾害构造（泥石流、滑坡等）的关系等方面的研究。  相似文献   

Site effects in Mexico City eight years after the September 1985 Michoacan earthquakes     

Francisco J. Chvez-García  Pierre-Yves Bard 《Soil Dynamics and Earthquake Engineering》1994,13(4)

The purpose of this paper is to take a comprehensive look at site effects in Mexico City for the 1985 Michoacan earthquake. We examine, successively, 1D and 2D models. For the latter, we consider in detail both large scale and small scale heterogeneities, using extensively the Aki-Larner wave propagation method, in the version given by Bard and Gariel. In particular, we make a critical review of the different explanations proposed for the large duration of strong ground motion in the lake zone. Our purpose is two-sided. We first outline the difference between what is well established and what remains still unexplained regarding the seismic response of Mexico City basin. On the other hand, we wish to make explicit the conditions that the proposed models require to explain strong motion duration. Our results allow us to qualify the models proposed to date and to point out what could be the experiments and the new data required to find a truly satisfactory explanation of strong ground motion at Mexico City.  相似文献