全文获取类型
收费全文 | 305篇 |
免费 | 5篇 |
国内免费 | 5篇 |
专业分类
测绘学 | 3篇 |
大气科学 | 23篇 |
地球物理 | 85篇 |
地质学 | 85篇 |
海洋学 | 26篇 |
天文学 | 66篇 |
自然地理 | 27篇 |
出版年
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 8篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 3篇 |
2013年 | 21篇 |
2012年 | 10篇 |
2011年 | 6篇 |
2010年 | 11篇 |
2009年 | 14篇 |
2008年 | 17篇 |
2007年 | 5篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 8篇 |
2003年 | 14篇 |
2002年 | 9篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 8篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1982年 | 3篇 |
1981年 | 6篇 |
1980年 | 2篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有315条查询结果,搜索用时 5 毫秒
311.
In the Buffalo Head Hills area a weights of evidence statistical approach was used to determine the spatial relationship of NNE-, NE-, NW-, and ENE-trending lineaments to known kimberlite locations. This method outlined different degrees of spatial correlation between and lineaments, with higher correlations defined for the NNE, NE, and ENE lineament data sets. A weights of evidence model then was constructed using the structural lineament maps, the Buffalo High and Buffalo Utikuma terrane boundary, Bouguer gravity data, and magnetic characteristics of the Buffalo High and Buffalo Utikuma terranes. The model reveals maximum favorability for kimberlite exploration along the Buffalo High and Utikuma terrane boundary in correspondence with NNE-trending lineaments and their intersections with NE and ENE lineaments. The relationship of the kimberlite occurrences along the Buffalo High-Buffalo Utikuma terrane boundary and structural lineaments seems to favor an hypothesis of kimberlite emplacement through a major zone of weakness in the basement, here characterized by the boundary between the Buffalo High and Buffalo Utikumaterranes. 相似文献
312.
Martin Sharp Keith Richards Ian Willis Neil Arnold Peter Nienow Wendy Lawson Jean-Louis Tison 《地球表面变化过程与地形》1993,18(6):557-571
As part of an integrated study of the hydrology, meltwater quality and dynamics of the Haut Glacier d'Arolla, Switzerland, the glacier's drainage network structure was determined from patterns of dye recovery in 342 injection experiments conducted from 47 moulins distributed widely across the glacier. This structure was compared with theoretical predictions based upon reconstructed patterns of water flow governed by (a) the subglacial hydraulic potential surface, and (b) the subglacial bedrock surface. These reconstructions were based on measurements of ice surface and bedrock topography obtained by a combination of ground survey and radio-echo sounding techniques. The two reconstructions simulate the drainage system structures expected for (a) closed channels, in which water is pressurized by the overlying ice, and (b) gravity-driven, open-channel flow. The closed-channel model provides the best fit to the observed structure, even though theoretical calculations suggest that, under summer discharge conditions, open-channel flow may be widespread beneath the glacier. Possible reasons for this apparent discrepancy are discussed. 相似文献
313.
314.
The results of potassium‐argon measurements are reported. Three samples from the southern end of the New England bathylith confirm its Permian age (240–245 m.y.). Two samples of the “pre‐Permian” granites are not younger than Lower Permian (Hillgrove, 270 m.y.; Barrington Tops, 260 m.y.). A sample of the analcite basalt from Spring Mountain gave an Oligocene age (34 m.y.) by measurements on two separate minerals. 相似文献
315.
Francesco?BoselloEmail author Robert?J.?Nicholls Julie?Richards Roberto?Roson Richard?S.?J.?Tol 《Climatic change》2012,112(1):63-81
This paper uses two models to examine the direct and indirect costs of sea-level rise for Europe for a range of sea-level
rise scenarios for the 2020s and 2080s: (1) the DIVA model to estimate the physical impacts of sea-level rise and the direct
economic cost, including adaptation, and (2) the GTAP-EF model to assess the indirect economic implications. Without adaptation,
impacts are quite significant with a large land loss and increase in the incidence of coastal flooding. By the end of the
century Malta has the largest relative land loss at 12% of its total surface area, followed by Greece at 3.5% land loss. Economic
losses are however larger in Poland and Germany (483 and483 and 391 million, respectively). Coastal protection is very effective
in reducing these impacts and optimally undertaken leads to protection levels that are higher than 85% in the majority of
European states. While the direct economic impact of sea-level rise is always negative, the final impact on countries’ economic
performances estimated with the GTAP-EF model may be positive or negative. This is because factor substitution, international
trade, and changes in investment patterns interact with possible positive implications. The policy insights are (1) while
sea-level rise has negative and huge direct economic effects, overall effects on GDP are quite small (max −0.046% in Poland);
(2) the impact of sea-level rise is not confined to the coastal zone and sea-level rise indirectly affects landlocked countries
as well (Austria for instance loses −0.003% of its GDP); and (3) adaptation is crucial to keep the negative impacts of sea-level
rise at an acceptable level. 相似文献