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   649篇
  免费   29篇
  国内免费   7篇
测绘学   15篇
大气科学   33篇
地球物理   193篇
地质学   246篇
海洋学   78篇
天文学   76篇
综合类   1篇
自然地理   43篇
  2023年   2篇
  2022年   10篇
  2021年   18篇
  2020年   28篇
  2019年   17篇
  2018年   27篇
  2017年   22篇
  2016年   33篇
  2015年   22篇
  2014年   35篇
  2013年   53篇
  2012年   23篇
  2011年   40篇
  2010年   39篇
  2009年   50篇
  2008年   42篇
  2007年   26篇
  2006年   28篇
  2005年   19篇
  2004年   21篇
  2003年   14篇
  2002年   17篇
  2001年   9篇
  2000年   8篇
  1999年   11篇
  1998年   7篇
  1997年   2篇
  1996年   6篇
  1995年   2篇
  1994年   6篇
  1993年   2篇
  1992年   5篇
  1991年   3篇
  1990年   4篇
  1989年   4篇
  1988年   3篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1981年   2篇
  1980年   1篇
  1979年   2篇
  1978年   4篇
  1977年   2篇
  1976年   2篇
  1975年   1篇
  1974年   5篇
  1973年   2篇
  1970年   1篇
排序方式: 共有685条查询结果,搜索用时 15 毫秒
61.
Acta Geotechnica - This paper presents a novel, exact, semi-analytical solution for the quasi-static drained expansion of a cylindrical cavity in soft soils with fabric anisotropy and structure....  相似文献   
62.
Mathematical Geosciences - In complex geological environments, the spatial domain characterization of different ore types has been one of the most important challenges in the assessment of mineral...  相似文献   
63.
Natural Hazards - The Hindu Kush Himalayan region is extremely susceptible to periodic monsoon floods. Early warning systems with the ability to predict floods in advance can benefit tens of...  相似文献   
64.
65.
66.
This study investigates the recent near-surface temperature trends over the Antarctic Peninsula.We make use of available surface observations,ECMWF’s ERA5 and its predecessor ERA-Interim,as well as numerical simulations,allowing us to contrast different data sources.We use hindcast simulations performed with Polar-WRF over the Antarctic Peninsula on a nested domain configuration at 45 km(PWRF-45)and 15 km(PWRF-15)spatial resolutions for the period 1991?2015.In addition,we include hindcast simulations of KNMI-RACMO21P obtained from the CORDEX-Antarctica domain(~50 km)for further comparisons.Results show that there is a marked windward warming trend except during summer.This windward warming trend is particularly notable in the autumn season and likely to be associated with the recent deepening of the Amundsen/Bellingshausen Sea low and warm advection towards the Antarctic Peninsula.On the other hand,an overall summer cooling is characterized by the strengthening of the Weddell Sea low as well as an anticyclonic trend over the Amundsen Sea accompanied by northward winds.The persistent cooling trend observed at the Larsen Ice Shelf station is not captured by ERA-Interim,whereas hindcast simulations indicate that there is a clear pattern of windward warming and leeward cooling.Furthermore,larger temporal correlations and lower differences exhibited by PWRF-15 illustrate the existence of the added value in the higher spatial resolution simulation.  相似文献   
67.
68.
69.
A spatially-homogenous and anisotropic cosmological model in self-creation theory of gravitation proposed by Barber is obtained when the source of gravitational field is a perfect fluid and the metric is of Marder's cyclindrically-symmetric form. Some properties of the model are discussed.  相似文献   
70.
A first estimate of the energy that reaches the Earth's surface and is produced by the inverse Compton effect between the electrons in the Van Allen belt and the solar flux was made. Since in the belt there are electrons with energies between 0.5 and 7 MeV, it was possible to use the Klein-Nishina formula in an approximate form and estimate the energy that is Compton scattered by all the electrons in the Van Allen belt by using Vette, Lucero and Bright's model. The result was compared (a) with the measurements of the continuum in the regions of soft X-rays, and (b) with the energy that is produced by the trapped electrons through the synchrotron mechanism.This paper was presented at the COSPAR meeting held in leningrad on May 20–29, 1970.  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