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   294篇
  免费   11篇
  国内免费   5篇
测绘学   33篇
大气科学   15篇
地球物理   54篇
地质学   118篇
海洋学   9篇
天文学   59篇
综合类   7篇
自然地理   15篇
  2022年   2篇
  2021年   6篇
  2020年   5篇
  2019年   4篇
  2018年   14篇
  2017年   14篇
  2016年   14篇
  2015年   11篇
  2014年   9篇
  2013年   17篇
  2012年   14篇
  2011年   12篇
  2010年   11篇
  2009年   11篇
  2008年   15篇
  2007年   13篇
  2006年   11篇
  2005年   8篇
  2004年   6篇
  2003年   6篇
  2002年   5篇
  2001年   4篇
  2000年   4篇
  1999年   5篇
  1998年   2篇
  1997年   5篇
  1996年   4篇
  1995年   5篇
  1994年   4篇
  1992年   2篇
  1991年   6篇
  1990年   5篇
  1989年   3篇
  1988年   5篇
  1987年   7篇
  1986年   4篇
  1985年   3篇
  1984年   3篇
  1983年   3篇
  1982年   3篇
  1981年   6篇
  1980年   2篇
  1979年   4篇
  1978年   4篇
  1977年   2篇
  1975年   1篇
  1972年   2篇
  1971年   1篇
  1969年   1篇
  1964年   1篇
排序方式: 共有310条查询结果,搜索用时 31 毫秒
271.
Nonradial oscillations of certain models of the generalized Roche series have been investigated numerically to further understand the nature of the eigen-values and the eigen-functions of the modes of nonradial oscillations of stellar models.  相似文献   
272.
The averaging technique of Kippenhahn and Thomas (1970) has been used in conjunction with Kopal's method of evaluating various parameters on the Roche equipotentials to determine the effects of rotation and tidal distortions on the periods of small adiabatic radial and nonradial modes of oscillations of polytropic models of the stars.  相似文献   
273.
The averaging technique of Kippenhahn and Thomas has been used in conjunction with Kopal's method of evaluating various parameters on the Roche equipotentials, to determine the effects of rotation and tidal distortions on the shapes and structures of the polytropic models of the stars.  相似文献   
274.
In the light of surface heat-flow observations, as well as other related geological and geophysical data, the origin of the Deccan basalts has been examined. The Indian lithosphere, after its detachment from Gondwanaland, apparently traversed a rising plume at La Réunion, which virtually bored through the lithosphere to emerge as the Deccan Trap volcanism on the surface. Subsequent volcanic and plutonic activity appears to have continued not only up to the Oligocene, as is indicated by the alkaline magmatic activity observed near the junction of the three prominent features — the West Coast faults, the Narmada-Son-Tapti lineament, and the Cambay Graben — but also up to the Mio-Pliocene, as indicated by the heat flow and gravity data over the Cambay Graben. The dyke-swarms and sills, which are mostly post-trappean, evolved from the lithosphere after the Indian Plate moved away from the hot spot.  相似文献   
275.
The auxiliary functions, namely amplitude, phase, envelope and instantaneous frequency of Hilbert transform over gravity anomalies of 2-D sphere, vertical fault block and horizontal circular cylinder are studied. The characteristics of these functions are established in locating and identifying the sources. The method is illustrated with a theoretical example in each case and supported by field data of gravity anomaly over Humble dome and spherical model of the Satak-Mansar area, Nagpur District, India.  相似文献   
276.
A simple method to interpret gravity gradients over a thin infinite dipping sheet is discussed. The Hilbert transform is used to compute the vertical gradient from the horizontal gradient of the gravity field. The method is illustrated with a theoretical example.  相似文献   
277.
Summary The method of continuation has been used to obtain the master curves for gravity and magnetic anomalies caused by spherical bodies. The procedure to calculate the depth of burial and radius of spherical bodies has been outlined.  相似文献   
278.
Summary It has been noted by several observers that no Love-wave spectrum is complete in the sense that it contains all the periods. The reason for this has been sought for in the presence of a low-velocity layer.  相似文献   
279.
The area around Panwari town, Hamirpur district, Uttar Pradesh, faces acute water scarcity and chronically drought prone. The groundwater resources in the area have not been fully exploited. The present study was undertaken to evaluate the groundwater prospective zones. Landsat TM and IRS-1A LISS-II data have been used to differentiate different hydromorphogeological units and to delineate the major trends of lineaments. The digitally enhanced False Colour Composite, Principal Component Analysis and Edge Detections were useful for better correlation. The digital enhancement was helpful with identification of faint lineaments. In addition, the boundaries of various lands forms were better discriminable on the digitally enhanced products. The deeply and moderately weathered buried pediplains are the most potential zones for groundwater targeting. Occurrence of lineaments in such zones is also a favourable indicator. A number of promising groundwater well sites have been located in the pediplains.  相似文献   
280.
The author discusses overpopulation as it affects public mental health by reviewing relevant literature in the fields of psychology and demography. The impact of population density in India is addressed.  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