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81.
广东省未来十年强震趋势分析   总被引:3,自引:3,他引:0  
1994年9月16日台湾海峡7.3级地震是70余年来广东及其近海地区最为突出的地震事件。后续的地震形势如何?本文以东南沿海地区为对象,研究了区内强震活动的时、空、强分布演化特征,综合分析认为,在目前新的地震活跃期中,广东省的强震形势值注意。  相似文献   
82.
亚洲地震委员会第二届会议暨地震危险性评估和地球内部相关论题讨论会于1998年12月1~3日在海得拉巴印度国家地球物理研究所召开。本次会议是由亚洲地震委员会(ASC)发起的,得到了国际地震学与地球内部物理学协会(IASPEI)、印度国家科学院、印度政府科学和工业研究委员会、印度政府科学技术部及联合国教科文组织共同发起。来自亚洲、南太平洋和世界其他国家的约200名科学家参加了会议,其中中国代表16名,IASPEI主席和秘书长及国际大地测量学与地球物理学联合会(IUGG)主席也出席了会议。会议共收到来自亚洲和世界其他国家的论文摘要189篇。本次会议的学术报告广泛涉及地震学、地震预报和地震危险性评估及地球内部相关论题,内容包括:地震预报与地震危险性评估、岩石层结构与过程、板内和板间区域构造与地震、地震过程的物理学、近期破坏性地震、诱发地震、热流与地壳热结构、地震学与其他地球物理学信息的传播和减轻地震灾害方面的公众教育的当前趋势等。在亚洲地震委员会第二届会议之前,印度国家地球物理研究所在联合国教科文组织、国际减灾十年秘书处、印度政府科学技术部等的赞助下,于1998年11月15~30日负责举办了地震监测、数据分析和交换  相似文献   
83.
This paper gives a brief review of some progress in the research and practice of earthquake prediction in China in terms of the study of strong earthquake cases in three disciplines of precursory means: crust deformation and strain, underground fluid dynamics, and geoelectro-magnettsm, summarized in the past 30-odd years. All the progress, however, shows that the research of earthquake prediction in China is still in the empirical stage of its development. The main tasks in this stage would involve the following aspects: (1) accumulating earthquake cases, particularly the cases of strong earthquakes with a wide variety of reliable precursory data observed by fixed or mobile networks of different disciplines; and (2) studying the physical mechanism of observational means in more detail and the synthetic model of earthquake preparation based on the theoretical and laboratory researches as well as the data of in-situ observation.  相似文献   
84.
This paper gives an overview of seismicity in China, including large-scale seismicity heterogeneity in space-time, aftershock activity, b-value, earthquake mechanism, and its possible mechanics.  相似文献   
85.
Quasi-trijunction is a type of popular structure for certain scale tectonic blocks in a continent. There are two kinds of quasi-trijunction in the conjoining area formed due to rotation of continental blocks. They are the clockwise type and the anticlockwise type of quasi-trij unction. The shape of a quasi-trij unction may be gradually changed associated with block rotation and tectonic evolution, but, sediments and structure in the conjoining area can record the history of tectonic evolution. Thus, studying a quasi-trij unction can reveal regional tectonic evolution.Regional tectonic movement, plane strain partitioning and characteristics of seismic activity can be studied based on kinematics and geometric analysis of a quasi-trijunction.The quasi-trijunction is a surface structure controlled by deep crustal movement. Tectonic activity may be different in three branches. In the quasi-trijunction in the northeastern corner of Qinghai-Xizang Plateau, the NWW-trending Qilianshan-Hexi corridor fault zone w  相似文献   
86.
The relationship between the strain cumulative rate (i.e., the crustal strain rate, or CSR in short) and seismic activity is analyzed to develop a new method to determine risky regions for strong shocks within recent years by the recorded crustal strain field. Seismic activity, especially the recurrence period, is different in different areas. Ding Guoyu (1984) pointed out that, for different seismic regions, the difference in the recurrence period of strong earthquakes is mainly controlled by their difference in the rate of the tectonic movement, which is controlled by the seismogenic environment and the tectonic conditions. The method of determining the risky regions for strong shocks from the gradient of vertical strain rates observed in a geodetic survey is preliminarily tested with the earthquakes in recent years; the results show that this method is effective and useful for earthquake prediction. The relationship between CSR and seismicity in a specific region is studied with strain theories, obse  相似文献   
87.
The Crust-Mantle Structure in Zhangbei-Shangyi Earthquake Area   总被引:4,自引:0,他引:4  
The seismic data obtained from the wide angle reflection and refraction profiles that pass through Zhangjiakou area of Hebei Province were interpreted. Some conclusions drawn from the result are as follows: (1) The nearly EW-trending Zhangbei-Chongli crustal fault zone and WNW-trending Zhangjiakou-Bohai Sea deep crustal fault zone meet in the Zhangbei earthquake (Ms = 6.2) area; (2) At the intersection, the two deep crustal fault zones that stretch to the Moho and the discontinuities of interfaces within the crust form the path for large area basalt eruption in Hannuoba; (3) In the earthquake area, the local velocity reversal in the middle-upper crust and abnormal low velocity zone in the lower crust imply that the magmatic activity there is still fairly violent; and (4) The recent activity of Zhangjiakou-Bohai Sea deep crustal fault zone may be the main cause of the Zhangbei earthquake.  相似文献   
88.
中国大陆若干地震构造带的地震准周期丛集复发行为   总被引:8,自引:3,他引:5  
以青藏高原东南缘和东北缘若干地震构造带的历史地震活动资料为基本数据,通过地震复发间隔的计算,分类和统计检验等,研究了大陆板内地震的复发行为。认为:大陆板内地震既不是简单地准周期重复发生,也不是简单地丛集复发,而可能是一种准周期的丛集复发行为,即地震丛是准周期重复发生的,而在某一地震丛内,地震又是丛集复发的。存在两类地震复发间隔,即地震丛复发间隔和地震丛内的地震复发间隔,它们分别满足对数正态分布和指数分布。在进行大陆板内活动断裂地震危险性定量计算和评估时,不能简单地套用N.B.实进模型中给出的地震复发间隔概率密度函数或累积分布函数,而应该根据当前地震的活动水平,判断当前是属于丛内的活跃期还是丛间的平静期,据此分别选用地震丛内地震复发间隔分布函数或者地震丛复发问题隔分布函数,这样将大大提高活动断裂地震危险性计算和定量评估的水平。最后,简要探讨了大陆板内地震准周期丛集复发行为的可能物理机制。  相似文献   
89.
全球卫星导航系统的进展   总被引:5,自引:1,他引:4  
介绍了欧洲全球卫星导航系统EGNOS与GALILEO系统,简要论述了美国GPS系统和俄国GLONASS系统发展的最新动向。  相似文献   
90.
精密弦矢导线法与边角导线法比较浅析   总被引:3,自引:2,他引:1  
精密导线法分为边角导线法和弦矢导线法,是监测水库拱坝水平位移的重要方法。弦矢导线法是根据导线边工变和矢距变化的观测值来得坝体的实际变形量;边角导线法则是根据导线边长变化和导线的转折角观测值来计算坝体的变形量。比较分析了边角导线法和弦矢导线法的设计原理与设计方法,认为精密弦矢导线法与精密边角导线法相比具有如下优点:(1)复测简单,速度快,劳动强度小;(2)精密高且稳定,不受折光等外界条件影响;(3)便于采用数字化遥测,可为实现位移值计算自动化奠定良好基础。  相似文献   
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