排序方式： 共有199条查询结果，搜索用时 15 毫秒
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Anhua He Gang Zhao Na Xue Jun Wang Bailin Guo Miaoxi Guo Zizhong Fu Institute of Crustal Dynamics China Earthquake Administration Beijing China Earthquake Administration of Tianjin Municipality Tianjin China China Earthquake Networks Center Beijing China 《地震学报(英文版)》2009,(1):101-106
Using Altera's Quartus Ⅱ,Nios Ⅱ IDE and Sopc Builder development tools,the proton precession magne-tometer principle host hardware platform is designed in a cyclone Ⅱ series FPGA chip(EP2C35).The proton precession magnetometer principle host core circuit's single-chip system-logic design is achieved by building and configuring the Nios Ⅱ soft-core processor,developing the IO interface and sensor control circuits,programming some hardware units' VHDL code,for example the equal precision cymometer and the DPL... 相似文献
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中国地震局地壳应力研究所科学技术处 《震灾防御技术》2006,1(3):283-284
2006年7月4日11时56分在河北省文安县(东经116.3°、北纬38.9°)发生5.1级地震,北京市、天津市、河北和山西均有震感。本文作者在地震现场调查的基础上,对比分析了我国其他大陆地区5级左右地震的人员伤亡和震害情况,探讨了此次地震未造成人员伤亡和较大损失的原因。 相似文献
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Time constraints for the closing of the Paleo-Asian Ocean in the Northern Alxa Region: Evidence from Wuliji granites 总被引：6，自引：0，他引：6
The Wuliji pluton in the Northern Alxa Region, Inner Mongolia, is the principal part of Shalazhashan Mountain. It belongs to the Zongnaishan-Shalazhashan Arc Zone, northwestern North China Plate, whose north is Engger Us Ophiolite Belt and south is Qagan Qulu Ophiolite Belt. The pluton was emplaced into Upper Carboniferous-Lower Permian Amushan Formation. According to the research about the original Carboniferous Amushan Formation, the lower and middle sections of the Carboniferous Amushan Formation consist of volcanic, clastic, and carbonate rocks, interpreted to represent the sedimentary association of a volcanic arc and back-arc basin; the upper section of the Amushan Formation is a molasse composed of silty shale, sandstone, gravel-bearing sandstone, and conglomerate. The Wuliji pluton consists mainly of biotite monzonitic granite, amphibole-bearing biotite monzonitic granite, and monzonitic granite. Geochemical analyses show that the pluton has both metaluminous and peraluminous characteristics, and on average has SiO2>70 wt%, Al2O3 >14 wt%, and high contents of Na2O+K2O (8.5 wt%), which define a calc-alkaline series. In addition, REE patterns show enrichment of LREE and weak negative Eu anomalies (δ Eu=0.3-1). Altogether, the samples are depleted in Nb, Ta, Ti, P, Sr, and Ba, and enriched in Rb, Th, and K. These geochemical traits are interpreted to reflect an arc component. A secondary ion mass spectrometry (SIMS) U-Pb zircon age of the biotite monzonitic Wuliji pluton in the Northern Alxa Region, Inner Mongolia, is 250.8±2.0 Ma (1σ). Samples have ε Nd (t) values between 0.1 and 1.3, which suggests that the granites were derived from mixing between the crust and mantle. Based on the SIMS age and geochemical characteristics, Wuliji granite is interpreted to be a post-collisional granite, the result of mantle-derived melt and assimilated juvenile arc crust. However, according to the newest international stratigraphic classification standard, the upper section of the Amushan Formation is Lower Permian in age, indicating that the back-arc basin had already closed in Early Permian. We conclude that the Paleo-Asian Ocean represented by the Engger Us Ophiolite Belt subducted southward in Late Carboniferous, at the same time that the trench-arc-basin system formed in the Northern Alxa Region. The Paleo-Asian Ocean was closed in Early Permian and the Northern Alxa Region entered a post-collisional period in the Late Permian, as indicated by the Wuliji granites. This suggests that the genesis of the Wuliji granites is consistent with the pluton emplacement at the upper crust, which occurred widely in the northern margin of the North China Plate in Late Carboniferous to Triassic. 相似文献
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Underpressured reservoirs are widespread in the Huatugou(花土沟) oilfield of the western uplift in Qaidam basin,western China.At depths between 462 and 1 248 m,the pressure of Neogene reservoirs in the Huatugou oilfield is only about 40% to 80% of hydrostatic pressure.Based on a study of the geological characteristics of these underpressured reservoirs,this work used fluid inclusion analysis and numerical simulation to investigate the mechanism creating these abnormal pressures and to evaluate the characterist... 相似文献
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用INSAR作地面沉降监测的试验研究 总被引：41，自引：17，他引：24
介绍了合成孔径雷达干涉测量进行天津市地区地面沉降监测的试验。对于试验区域，原始资料选取的原则，剪裁出的试验区域的影像进行InSAR处理都作了简要的说明，最后将利用D－InSAR得到的天津市区的地面沉降监测结果与水准测量的监测结果进行了对比，并据此得到一些初步认识。 相似文献
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火山地区重力场变化的数值模拟 总被引：1，自引：0，他引：1
推导了火山活动引起的重力变化与地面三维位移场变化的表达公式，讨论了火山活动引起重力场变化的时空分布特征。根据火山活动的特点，采用张开型矩形位错理论模型对火山活动过程引起的地面重力场变化进行了数值模拟，并对一些火山地区观测到的重力变化进行理论解释。 相似文献
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川滇地区地壳水平运动特征与强震关系研究 总被引：15，自引：8，他引：7
通过对1991～1999、1999～2001年川滇地区GPS水平运动资料的非震负位错模型反演和形变应变场时空演化分析，结合地质构造，研究了块体及边界带的构造变形特征及其与强震蕴育的关系。结果表明：①总体上本区呈现近SE向滑移叠加绕垂直轴顺时针转动的复合运动，1999～2001较1991～1999年运动速率及应变率减弱；②强震多发生在形变差异显著的块体边界附近和块体边界断层带的高应变积累闭锁段及其附近，以及区域应变率高值区及其边缘；③目前差异运动显著的块体边界带、断层闭锁段及区域应变率高值区有丽江—小金河断裂及其与剑川断裂交汇区、金沙江断裂与理塘—德巫断裂交汇区、安定河—则木河断裂、红河断裂中东段及其与小江断裂交汇区、怒江及澜沧—勐遮断裂。 相似文献
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在评述中国地壳形变、应变连续观测技术３０年发展成就的基础上，论述和分析建立我国地壳形变、应变连续观测台网数字化网络系统的必要性及实施思路和方法。提出了该领域待深入研究的几个问题，为本领域跨世纪持续发展、跟踪国际前沿做好技术准备 相似文献
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中国大陆地壳应力环境基础数据库及查询系统 总被引：2，自引：1，他引：1
通过对现有6大类主要地应力基础数据资料——震源机制解、水压致裂、钻孔崩落、应力解除、断层滑动和连续应力应变观测数据的收集整理，建成了便于更新的“中国大陆地壳应力环境基础数据库”。介绍了数据库的结构及其查询分析系统。数据库通过Microsoft Access数据库系统建立，其中震源机制解和水压致裂采用双数据表结构设计，丰富了数据库的数据信息。数据库查询分析系统以MapInfo地理信息系统为技术支持平台，依据“中国大陆地壳应力环境基础数据库”中的数据信息，自动生成空间数据库，实现了地应力数据的地图显示。以此为基础，系统提供了包括可视化地图查询和条件查询在内的多种数据库查询方式，实现了空间图形数据与文本属性数据的相互查询。另外，数据库查询分析系统还提供了地应力研究成果查询、应力方向大小统计分析、专题图及其它辅助功能。 相似文献