中国大陆地壳现今运动的GPS测量结果与初步分析   总被引：9，自引：8，他引：1  

游新兆  杜瑞林  王琪  乔学军  华晓伟 《大地测量与地球动力学》2001,21(3):1-8

利用中国大陆及周边地区 1991～ 2 0 0 0年间一系列全球定位系统 (GPS)观测资料 ,计算了 340个GPS站点的位移速率 ,得到了统一的中国大陆现今地壳运动速率场。这些站主要集中于青藏高原及其周缘的喜马拉雅、川滇、河西走廊、阿尔金、天山 ,以及华北、福建东南沿海等主要构造活动区。固定测站速率精度优于 1mm/a ,流动测站速率精度优于 3mm/a。根据GPS结果对中国大陆现今地壳运动的状况进行了分析。  相似文献   

Research on Relationship between Elastic and Plastic Deformation of Material     

Li You Chen  Zhida Zhu  Weishen 《岩土力学》1988,9(3):41-50

Based on a lot of experiment results, it is put forward that the elastic part and plastic part of deformation of general metal material, and isotropic homogeneous, and continuous rock material follow a law—the relative law of elastic and plastic deformation. The law results from testing study and is partly proved theoretically.  相似文献   

长江三峡工程诱发地震监测系统中的GPS监测网及其观测结果   总被引：1，自引：1，他引：0  

杜瑞林  游新兆  乔学军 《大地测量与地球动力学》2001,21(1):46-52

阐述长江三峡工程诱发地震监测系统中的 GPS监测网的设计思路 ,并介绍了该网的第一、二期观测情况及数据处理结果。认为该网无论是技术设计还是运行质量 ,均达到世界一流的先进水平 ,其站间基线长度及其分量的测定精度优于 5mm。  相似文献   

江蓠新品种培育     

曾淑芳  刘思俭  揭振英  吴丽荷  尤春暖  费修绠  张学成 《广东海洋大学学报》1990,(1)

目前我国人工栽培江蓠分为两种主要方式:一是在半咸淡水塘中地播栽培细基江蓠繁枝变种,种苗容易解决,栽培方法简单,产量较高,但琼胶含量低;另一种是在浅滩上用浮筏式夹苗栽培真江蓠、细基江蓠、龙须菜等,培养种苗较麻烦,且产量较低,成本也较高,但琼胶含量高,质量也较好。为取两者的优点,我们把细基江蓠繁枝变种和细基江篱进行杂交,得出了杂交种。实验室培养结果表明,杂交种的琼胶含量介于两者之间,能在半咸淡水中正常生长。初步认为是一个适合于半咸淡水塘中栽培的优良品种,很有发展前途。  相似文献   

Dynamic stiffness matrix of a poroelastic multi-layered site and its Green＇s functions   总被引：3，自引：1，他引：2  

梁建文  尤红兵 《地震工程与工程振动(英文版)》2004,3(2):273-282

Few studies of wave propagation in layered saturated soils have been reported in the literature. In this paper, a general solution of the equation of wave motion in saturated soils, based on one kind of practical Biot‘s equation,was deduced by introducing wave potentials. Then exact dynamic-stiffness matrices for a poroelastic soil layer and halfspace were derived, which extended Wolf‘s theory for an elastic layered site to the case of poroelasticity, thus resolving a fundamental problem in the field of wave propagation and soil-structure interaction in a poroelastic layered soil site. By using the integral transform method, Green‘s functions of horizontal and vertical uniformly distributed loads in a poroelastic layered soil site were given. Finally, the theory was verified by numerical examples and dynamic responses by comparing three different soil sites. This study has the following advantages: all parameters in the dynamic-stiffness matrices have explicitly physical meanings and the thickness of the sub-layers does not affect the precision of the calculation which is very convenient for engineering applications. The present theory can degenerate into Wolf‘s theory and yields numerical results approaching those for an ideal elastic layered site when porosity tends to zero.  相似文献   

Scattering of SV waves by a canyon in a fluid-saturated, poroelastic layered half-space, modeled using the indirect boundary element method     

Jianwen Liang  Hongbing You  Vincent W. Lee   《Soil Dynamics and Earthquake Engineering》2006,26(6-7):611-625

The scattering of SV waves by a canyon in a fluid-saturated, poroelastic layered half-space is modeled using the indirect boundary element method in the frequency domain. The free-field responses are calculated to determine the displacements and stresses at the surface of the canyon, and fictitious distributed loads are then applied at the surface of the canyon in the free field to calculate the Green's functions for displacements and stresses. The amplitudes of the fictitious distributed loads are determined from the boundary conditions, and the displacements arising from the waves in the free field and from the fictitious distributed loads are summed to obtain the solution. The effects of fluid saturation, boundary conditions, porosity, and soil layers on the surface displacement amplitudes and phase shifts are discussed, and some useful conclusions are obtained. It is shown that the surface displacement amplitudes due to saturation and boundary conditions, different porosities, or the presence of a soil layer can be very dissimilar, and large phase shifts can be observed. The resulting wavelengths for an undrained saturated poroelastic medium are slightly longer than those for a drained saturated poroelastic medium; and are longer for a drained saturated poroelastic medium than those for a dry poroelastic medium. As porosity increases, the wavelengths become longer; and a layered half-space produces longer wavelengths than a homogeneous half-space.  相似文献   

Assessing the spatial distribution of crop areas using a cross-entropy method   总被引：1，自引：0，他引：1  

Liangzhi You  Stanley Wood 《International Journal of Applied Earth Observation and Geoinformation》2005,7(4):310-323

While crop production statistics are reported on a geopolitical – often national – basis, we often need to know, for example, the status of production or productivity within specific sub-regions, watersheds, or agro-ecological zones. Such re-aggregations are typically made using expert judgments or simple area-weighting rules. We describe a new, entropy-based approach to the plausible estimates of the spatial distribution of crop areas. Using this approach tabular crop production statistics are blended judiciously with an array of other secondary data to assess the areas of specific crops within individual ‘pixels’—typically 25–100 km² in size. The information utilized includes crop production statistics, farming system characterization, satellite-based interpretation of land cover, biophysical crop suitability assessments, and population density. An application is presented in which Brazilian state level production statistics are used to generate pixel level crop area data for eight crops. To validate the spatial allocation we aggregated the pixel estimates to obtain synthetic estimates of municipality level areas in Brazil, and compared those estimates with actual municipality statistics. The approach produced extremely promising results. We then examined the robustness of these results compared to simplified approaches to spatializing crop production statistics and showed that, while computationally intensive, the cross-entropy method does provide more reliable spatial allocations.  相似文献   

交叉型报表技术在GIS中的应用     

万幼 《测绘信息与工程》2005,30(2):23-24

分析了交叉型报表模版单元的内部结构,探寻了将ＳＱＬ语句嵌入交叉型报表表模版的基本单元,实现了报表快速自动创建的技术。  相似文献   

迂里矿段铜铅锌银多金属矿体地质特征及其矿床成因     

王友谊 《江苏地质》2005,29(1):14-17

苏州迂里矿区位于苏州西部太湖之滨，其中迂里矿段铜、铅、锌、银多金属矿体具有埋藏较深，规模较小，品位较高及可综合利用元素较多的特点。矿体受地层岩性、构造、岩体等因素控制，确定了成矿的5个规律。  相似文献   

Deformation Pattern and Holocene Slip Rate Along the Fukang Fault in Eastern Tianshan,China     

You Huichuan  Ren Lisheng  Chen Guoxing  Wang Weijun 《中国地震研究》2002,16(4):369-379

The deformation pattern nd Holocene slip rate along the Fukang fault in Eastern Tianshan,China are analyzed and studied using the data obtained in field investigation.The result indicates that the Fukang fault consists of 4 low-angle south-dipping thrust faults with stepover,displaying recent tectonic activity.The movement along the termination parts of the fault is weaker,with an average vertical slip rate of 0.13-0.33mm/a in Holocene,and along the middle part of the fault is stronger,with an average vertical slip rate larger than 1.42mm/a in Holocene.The Holocene deformation pattern along the fault displays generally steady slip,multi-phase intermittent movement along its western segment,and persistent movement along its middle and eastern segments.which have caused rapid dislocation up to the surface in an earlier phase.  相似文献