首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   153篇
  免费   20篇
  国内免费   2篇
测绘学   3篇
大气科学   13篇
地球物理   122篇
地质学   21篇
天文学   1篇
综合类   4篇
自然地理   11篇
  2023年   1篇
  2021年   5篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   3篇
  2016年   4篇
  2015年   13篇
  2014年   4篇
  2013年   5篇
  2012年   2篇
  2011年   5篇
  2010年   2篇
  2009年   7篇
  2008年   12篇
  2007年   9篇
  2006年   7篇
  2005年   9篇
  2004年   4篇
  2003年   4篇
  2002年   4篇
  2001年   8篇
  2000年   14篇
  1999年   10篇
  1998年   4篇
  1997年   5篇
  1996年   2篇
  1995年   3篇
  1994年   4篇
  1993年   6篇
  1992年   2篇
  1991年   4篇
  1990年   1篇
  1989年   2篇
  1988年   3篇
  1987年   1篇
  1986年   1篇
  1983年   1篇
排序方式: 共有175条查询结果,搜索用时 375 毫秒
71.
GPS在现今地壳运动与地震监测中的初步应用   总被引:4,自引:0,他引:4  
以“中国地壳运动观测网络”科学工程项目产出的GPS观测资料为基础 ,采用球坐标系下非连续变形算法对资料进一步做了形变计算 ,以此为基础 ,对我国大陆地块及其边界带运动与形变进行了分析。对GPS基准站的连续观测序列采用小波变换进行分解变换 ,分析了部分震例 ,探讨了GPS连续观测序列提取地震前兆的方法。  相似文献   
72.
The Kamchatka peninsula, located in the far east of Russia, is a geologicallyactive margin where the Pacific plate subducts beneath the North Americanand Eurasia plates. This area is characterised by frequent and strong seismicactivity (with magnitudes of up to 8.6), with epicentres generallydistributed offshore along the eastern coast of the peninsula. Starting in1977, hydrogeochemical data have been collected with a mean samplingfrequency of three days in wells and springs located in the southern area ofthe Kamchatka peninsula. In order to reveal possible earthquake precursors,the groundwater gas content data collected in the last ten years at fivewells, were statistically analysed. Each signal exceeding a 3threshold was considered to be an irregularity and two different methodsof defining an anomaly were assumed. In the first, an anomaly was declaredwhen an irregularity occurred simultaneously on more than one gas contentat each well. In the second method, an anomaly was declared when anirregularity occurred simultaneously on a given type of gas at more thanone well. As a mechanism for associating an anomaly with an earthquake,the earthquakes that occurred with magnitudes greater than 6.5 and withina distance of 250 km from each well, were selected. Using this frameworkboth successes and failures were identified. It is shown that on the basis ofthis statistical analysis, there is a great probability that the successes revealedare not precursors but random coincidences.  相似文献   
73.
上官志冠 《中国地震》1996,12(2):202-208
本文根据1993年6月至1994年1月滇西及其邻近地区数次中强以上地震前CO2,N2,Ar,Rn等气体组分释放动态的观测结果,研究了气体的物质迁移对其前兆异常变化的影响,发现深,浅源气体的震前趋势性异常释放和短临突跳异常的发生时间具有明显的有序性,基本模式是源自深部的气体组分的震前异常变化总是上先于浅源气体,这种现象在强震发生前更为明显。作者认为,导致深一浅源气体异常变化有序发生的原因与气体物质迁  相似文献   
74.
Large volumes of rock mass, mined-out and moved within these deposits, resulted in irreversible changes in the geodynamic regime in the upper earth's crust of the adjacent territory. These changes manifest themselves in a more frequent occurrence of such intensive dynamic phenomena as tectonic rock bursts due to fault movement adjacent to the area which is mined-out and man-made earthquakes which sharply decrease mining safety and result in great material losses.To develop the prediction techniques of such phenomena, a monitoring system is created, based on the program of the Kola Complex of geodynamic measuring stations. Most of this system is realized in the region of the Khibiny apatite mines. The system provides regional seismological monitoring, local prediction of seismicity in separate areas of a rock mass and, determination of stress and strain in rock masses, local geophysical monitoring over the state of rocks in a rock mass as well as physical and mathematical modelling of geodynamic processes in the upper earth's crust.The investigations have resulted in the distinguishing of some regularities in manifestations of induced seismicity and tectonic rock bursts and in the determination of strain precursors of intensive seismic events in the Khibiny mines.The mechanism is provided by the induced seismicity which resulted from the anthropogenic impact on the geological medium. A geodynamic monitoring complex is described, which is used to reveal the precursors of powerful seismic eventsin situ, and monitoring results are shown, obtained in the Kola Complex of geodynamic stations. Methods of preventing tectonic rock bursts and induced earthquakes are presented.  相似文献   
75.
电测量在中国地震预报中的应用   总被引:25,自引:2,他引:25       下载免费PDF全文
唐山等大地震地电阻率中期下降系压缩应变积累所致 ,为基线缩短、井水位下降所支持。地电阻率、自然电位对起潮力的异常响应及自然电位快急始、慢衰减特殊图象与废油井喷油同步等短临前兆 ,与中期前兆相反显示出向震中迁移的规律 ,表明能量积累从震中向外围传播 ,而能量释放从外围向震中传播。海城地震时喷砂冒水可引起自然电位垂直分量跃变及地光。IIMT法和过剩海洋电流H极化结果表明 ,唐山地震与地壳高阻层及其中存在深大断裂有  相似文献   
76.
There are many reports about the abnormal electromagnetic signals observed before great earthquakes. In particular, the signals of electromagnetic anomalies before the Hyogo-Ken Nanbu, Japan, MS=7.2 earthquake on January 17, 1995 (Hayakawa, et al, 1996) and those before the Loma Prieta, USA, MS=7.1 earthquake on October 19, 1989 (Fraser-Smith, et al, 1990) are especially remarkable. However, what the above authors reported are only the phenomena of one or two observatories. In order to …  相似文献   
77.
78.
This paper aims to analyse the geoelectrical resistivityρ s data on the dipole electrode sounding, which were firstly accumulated from the earthquake prone region in China. The analyses on the one order difference value of the geoelectrical resistivity indicated that, firstly, more than 4 percent of theρ s data reveals the precursors by 3 to 76 days ahead the earthquakes occurring, with the magnitude range of 4 ≤M ≤ 6. 4, in a region of 100 km around the station, and secondly, the results revealed that the seasonal variation ofρ s data were slight. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 211–219, 1992.  相似文献   
79.
小波变换在前兆观测资料分析中的应用   总被引:4,自引:3,他引:4  
由于数字化前兆具有高精度特点,因此,如何分离数字化前兆中的高频与低频信息,以及如何识别地震前兆的趋势异常与短期异常,是数字化前兆资料分析应用中的一个重要问题。本文给出了小波变换应用于正常的数字化前兆资料高频与低频信息的分离方法,并实际应用于地震前兆观测资料的处理,结合实例给出了地震前兆的趋势异常与短期异常的识别思路,从而为数字化前兆的趋势异常与短期异常的识别提供了一种新的有效方法。  相似文献   
80.
Digital data of precursors is noted for its high accuracy. Therefore, it is important to extract the high frequency information from the low ones in the digital data of precursors and todiscriminate between the trend anomalies and the short-term anomalies. This paper presents a method to separate the high frequency information from the low ones by using the wavelet transform to analyze the digital data of precursors, and illustrates with examples the train of thoughts of discriminating the short-term anomalies from trend anomalies by using the wavelet transform, thus provide a new effective approach for extracting the short-term and trend anomalies from the digital data of precursors.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号