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81.
Gil A. J. Rodríguez-Caderot G. Lacy M. C. Ruiz A. M. Sanz de Galdeano C. Alfaro P. 《Studia Geophysica et Geodaetica》2002,46(3):395-410
The Granada Basin (Central Betic Cordillera), one of the most seismically active areas of the Iberian Peninsula, is currently subjected to NW-SE compression and NE-SW extension. The present day extension is accommodated by normal faults with various orientations but particularly with a NW-SE strike. At the surface, these active NW-SE normal faults are mainly concentrated on the NE part of the Basin. In this part we have selected a 15-km long segment where several active normal faults crop out. Using the marine Tortonian rocks as a reference, we have calculated a minimum extensional rate of 0.15-0.30 mm/year. The observed block rotation, the listric geometry of faults at depth and the distribution of seismicity over the whole Basin, indicate that this rate is a minimum value. In the framework of an interdisciplinary research project a non-permanent GPS-network has been established in the central sector of Betic Cordillera to monitor the crustal deformations. The first two observation campaigns were done in 1999 and 2000. 相似文献
82.
珠江三角洲地区一体化交通运输网络发展构想 总被引:4,自引:0,他引:4
从区域经济一体化角度分析了珠江三角洲经济区交通运输的现状、问题和发展趋势,提出了建设一体化交通运输网络的基本思路和总体构想。认为珠三角交通运输设施虽然种类齐全且发展迅速,但还存在数量、质量、结构、布局等方面与区域经济一体化和未来发展趋势不相适应的问题;为了促进区域经济一体化,交通运输应从被动适应变为主动发展并引导城镇体系和生产力布局,从注重设施数量变为强调设施质量并向高速高效型发展;应该分4个层次建设3个枢纽和3大组团并与大运量快速干线相连接,构建区域一体化的交通运输网络。 相似文献
83.
Exploration for volcanogenic massive sulfide deposits of the kuroko-type is underway in many places. Clarifying the spatial patterns of the metals in kuroko deposits will be useful for understanding their genetic mechanisms and for future exploration of such types of deposits. This study represents a spatial distribution analysis on the contents of principal metals of kuroko deposits: Cu, Pb, and Zn, in the Hokuroku district, northern Japan, by a feedforward neural network and 1917 sample data at 143 drillhole sites. The network, which consists of three layers, was trained by the principle of SLANS in which the numbers of neurons in the middle layer and training data are changed to improve estimation accuracy. Using the weight coefficients connecting adjacent neurons, sensitivity analysis of the neural network was carried out to identify factors influencing spatial distributions of the three metals. The coordinates depth (z) direction, Bouguer gravity, and specific lithology such as dacite were determined to be influencing factors. The high frequency of the z coordinate signifies that the metal contents differ to a large extent by depth. The sensitivity vector was defined using sensitivity coefficients for x, y, and z coordinates of an estimation point. We determined that the directions of large vectors were different inside and outside of the Hanawa-Ohdate area. This characteristic is considered to originate from the differences in the permeability of fractures that became the paths for rising ore solutions, and the depths that the solutions mixed with sea water. 相似文献
84.
介绍了当前湖泊水下地形测量的一般方法和作业过程。针对逐点插入构建不规则三角网算法,本文提出了效率改正算法和格网索引号快速计算算法。基于不规则三角网,给出了湖泊水下数字高程模型的一般应用模型——任意点高程计算、填挖方计算模型及等深线计算模型。 相似文献
85.
平原河网区域来水组成原理 总被引:1,自引:0,他引:1
对于一般树状分布河网,上一级河道总是汇入至下一级河道,位于河道下游断面的流量总是由其上游汇集而至。但对于平原河网地区,特别是人工控制建筑物众多,又受潮汐影响的地区(如太湖流域),河网错综复杂,水流方向不定,要跟踪某个断面的水流去向,或某个河段的水体、断面流量是从哪里汇集而来的,非常困难。但这样的问题在生产实践中往往对其很感兴趣。例如从常熟枢纽引长江水流进入望虞河后,流向何处?河网各断面流量中或各河段水体中常熟枢纽引江水量占多少比重?对这些问题的研究可以估计常熟枢纽引江的效果和影响范围。因此,平原河网区域来水组成方法在生产实践中具有重要意义。重点介绍了平原河网区域来水组成原理及其在太湖流域的应用。 相似文献
86.
宽带接入用户认证技术分析与比较 总被引:2,自引:0,他引:2
给出了一个宽带接入用户认证系统的基本模型,并基于此模型对目前被广泛应用的PPPoE、WEB、DHCP等用户认证技术进行了分析与比较。最后,简单介绍了用户认证技术的新成员-802.1x(Port Based Network Access Control Protoco1)协议。 相似文献
87.
88.
何少林 《地震地磁观测与研究》2003,24(1):60-64
介绍了地震信号传输的常用方式及各自的优缺点,提出了数字遥测地震台网信号传输方式设计的总原则和基本原则。实际应用表明,兰州数字遥测地震台网信号传输方式的是符合要求的,提出的数字遥测地震台网信号传输方式的总原则和基本原则,对数字遥测地震台网建设有直接的借鉴作用。 相似文献
89.
岩体三维不连续裂隙网络及其逆建模方法 总被引:3,自引:0,他引:3
通过拟合实测的二维裂隙编录图和钻孔裂隙编录图,优化裂隙三维大小和密度参数,使模型能够准确再现野外所观测到的实际现象,包括开挖面和钻孔上不同裂隙的数量、密度和长度,通过计算实例验证了方法的可行性。 相似文献
90.
This paper illustrates the seismic risk preliminary estimates of two different groups of structures located on the territory of the Friuli–Venezia Giulia region (NE Italy) : the first group includes some special industrial plants, and the second group includes bridges and tunnels belonging to the regional highway network. The part of the study on special industrial plants tries to evaluate the degree of expected damage, taking into account their structural typology and ground shaking expressed in terms of macroseismic intensity. The second part of the study is an application of the HAZUS methodology to the tunnels and bridges of a highway network: the combination of expected ground shaking and the construction characteristics lead to very different risk levels, especially when considering the bridges. The resulting damage levels to bridges and tunnels are still only indicative because of the fragility curves used in the evaluations: they were developed for existing bridge and tunnel structural typologies in the U.S.A. Moreover, both examples show the power of GIS technology in storing, elaborating, and mapping spatial data. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献