全文获取类型
收费全文 | 4071篇 |
免费 | 165篇 |
国内免费 | 52篇 |
专业分类
测绘学 | 108篇 |
大气科学 | 316篇 |
地球物理 | 863篇 |
地质学 | 1517篇 |
海洋学 | 270篇 |
天文学 | 826篇 |
综合类 | 15篇 |
自然地理 | 373篇 |
出版年
2021年 | 45篇 |
2020年 | 69篇 |
2019年 | 91篇 |
2018年 | 101篇 |
2017年 | 118篇 |
2016年 | 130篇 |
2015年 | 107篇 |
2014年 | 138篇 |
2013年 | 204篇 |
2012年 | 141篇 |
2011年 | 208篇 |
2010年 | 176篇 |
2009年 | 238篇 |
2008年 | 195篇 |
2007年 | 195篇 |
2006年 | 180篇 |
2005年 | 159篇 |
2004年 | 151篇 |
2003年 | 118篇 |
2002年 | 116篇 |
2001年 | 79篇 |
2000年 | 72篇 |
1999年 | 71篇 |
1998年 | 63篇 |
1997年 | 67篇 |
1996年 | 65篇 |
1995年 | 57篇 |
1994年 | 37篇 |
1993年 | 40篇 |
1992年 | 39篇 |
1991年 | 44篇 |
1990年 | 32篇 |
1989年 | 37篇 |
1988年 | 39篇 |
1987年 | 46篇 |
1986年 | 32篇 |
1985年 | 46篇 |
1984年 | 32篇 |
1983年 | 23篇 |
1982年 | 42篇 |
1981年 | 43篇 |
1980年 | 32篇 |
1979年 | 24篇 |
1978年 | 21篇 |
1977年 | 29篇 |
1976年 | 32篇 |
1975年 | 21篇 |
1974年 | 35篇 |
1973年 | 22篇 |
1971年 | 21篇 |
排序方式: 共有4288条查询结果,搜索用时 187 毫秒
1.
Earth, Moon, and Planets - 相似文献
2.
3.
4.
5.
Maarten A. Prins Hongbo Zheng Kay Beets Simon Troelstra Patrick Bacon Ilse Kamerling Wouter Wester Martin Konert Xiangtong Huang Wang Ke Jef Vandenberghe 《第四纪科学杂志》2009,24(1):75-84
The Mangshan Plateau is located on the south bank of the Huang He (Yellow River) just west of the city of Zhengzhou, well outside the Loess Plateau in central China. Mixing models of the grain‐size data indicate that the loess deposits are mixtures of three loess components. Comparison of the mixing model with existing models established for a series of loess–palaeosol sequences from the Loess Plateau indicates that the Mangshan loess has been supplied from a proximal dust source, the Huang He floodplain, during major dust outbreaks. The high accumulation rates, the composition of the loess components, and especially the high proportions of a sandy loess component support this. Owing to the exceptionally high accumulation rates, the Mangshan grain size, magnetic susceptibility and carbonate records provide a high‐resolution archive of environmental and climate change. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
6.
7.
8.
We present warm dark matter (WDM) as a possible solution to the missing satellites and angular momentum problem in galaxy
formation and introduce improved initial conditions for numerical simulations of WDM models, which avoid the formation of
unphysical haloes found in earlier simulations. There is a hint, that because of that the mass function of satellite haloes
has been overestimated so far, pointing to higher values for the WDM particle mass.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
9.
With the Planck and Herschel satellite missions of the European Space Agency, the far-infrared and submillimeter window will offer new investigation tools toward clusters of galaxies in the distant Universe. These are the Sunyaev Zel'dovich (SZ) effect of the cosmic microwave background and the thermal emission of dust grains. The power of the SZ effect is such that Planckis expected to discover thousands of new clusters at redshifts larger than 0.2, where only a few tens are known today. The dust can be present at large scale in the intracluster medium, and we show that even at very low abundances it is able to be a major cooling agent for the whole cluster. However the dominating dust emission will be that of the background infrared star forming galaxies. In all cases, the data processing of space borne sensitive submillimeter observations of clusters of galaxies such as the one that Planck and Herschel will provide, will require a very carefull combined analysis of the SZ effect and dust thermal emission. 相似文献
10.
Using photoclinometry, topographic profiles across europan ridges have been produced. These profiles allow the identification of bulges in the terrain adjacent to the ridges. The bulges are assumed to have been produced by flexure of the elastic lithosphere due to the load of the ridges, which lie along cracks in the crust. The distance from the crack to these “fore-bulges” depends on the thickness of the elastic plate being flexed. Based on a survey of ridges in Galileo images with resolution <300 m/pixel, the thickness of the elastic lithosphere has been determined by this method at a wide variety of sites along the leading and trailing hemispheres of Europa. The average thickness is about 200 m. The elastic lithosphere underneath smooth dilational bands tends to be thicker than plains morphology, an effect that is pronounced at Thynia Linea and Astypalaea Linea. Among the ridges investigated here, more recent loading correlates with a thicker elastic lithosphere, which may either reflect an intrinsically thicker layer, or less viscous relaxation over the shorter time period. 相似文献