全文获取类型
收费全文 | 224篇 |
免费 | 20篇 |
国内免费 | 157篇 |
专业分类
测绘学 | 5篇 |
大气科学 | 65篇 |
地球物理 | 70篇 |
地质学 | 176篇 |
海洋学 | 51篇 |
天文学 | 14篇 |
综合类 | 6篇 |
自然地理 | 14篇 |
出版年
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 9篇 |
2018年 | 13篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 12篇 |
2013年 | 27篇 |
2012年 | 8篇 |
2011年 | 21篇 |
2010年 | 16篇 |
2009年 | 19篇 |
2008年 | 26篇 |
2007年 | 7篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 11篇 |
2002年 | 14篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1988年 | 3篇 |
1984年 | 3篇 |
1975年 | 4篇 |
1965年 | 3篇 |
1964年 | 3篇 |
1963年 | 3篇 |
1960年 | 2篇 |
1959年 | 2篇 |
1957年 | 2篇 |
1954年 | 2篇 |
1950年 | 2篇 |
1948年 | 2篇 |
1942年 | 7篇 |
1938年 | 3篇 |
1934年 | 9篇 |
1928年 | 4篇 |
1926年 | 6篇 |
1925年 | 3篇 |
1924年 | 4篇 |
1923年 | 2篇 |
1922年 | 2篇 |
排序方式: 共有401条查询结果,搜索用时 15 毫秒
301.
正Dear Members of the Editorial Board,Contributors and Friends,2018 is the tenth anniversary of the Wcnchuan earthquake disaster.To commemorate the Wenchuan earthquake disaster,the journal of Earthquake Engineering and Engineering Vibration(EEEV)will publish special sections with invited papers in the issues of 2018.We sincerely appreciate the contributions from the following experts:Professor Masayoshi NAKASHIMA.Professor Hongnan LI,and Professor Ying ZHOU. 相似文献
302.
The Shihmen reservoir is an important water source for about 3.4 million people in northern Taiwan. To protect reservoir water quality,it is necessary to conserve and manage the associated watersheds. Riparian buffer strips can trap pollutants emitted near a watershed.The location and design of a buffer strip can influence its pollutant-trapping efficiency.Any commitment of land for use as a riparian buffer strip must consider the project’s economic effectiveness.The present research is a cost-benefit analysis of various possible land developments in the Shihmen reservoir watershed.This study has applied a regression equation to evaluate pollutant-trapping efficiency levels of riparian buffer strips of various widths.Planned buffer strips have been evaluated in terms of net economic effectiveness and benefit-cost ratio.Results indicate that the optimal buffer strip width is 30 m for the Shihmen reservoir watershed. 相似文献
303.
Abstract— We re‐examined the buried Woodleigh structure in Western Australia, which has been inferred to be a multi‐ringed, 120 km diameter impact crater, because the proposed size and possible synchronicity with one of the pre‐Mesozoic mass extinction events has attracted controversy. We undertook a detailed study of the petrology and mineralogy of a number of samples of core from the Woodleigh‐1 borehole that was drilled into the central uplift of the structure. Crystalline Proterozoic basement rocks comprising granites and gneisses in the Woodleigh‐1 core contain minor brecciation in discrete veins and reveal clear evidence of shock metamorphism over the full extent of the core. Imaging of laboratory‐etched quartz showed that a large number of grains contain shock deformation lamellae. Microstructural and crystallographic analysis of these lamellae by TEM showed that they are planar deformation features (PDFs) that have subsequently undergone annealing and water assisted recrystallization. The available geological, petrographic, and mineralogical evidence suggest that Woodleigh is an eroded impact crater that is nearer to 60 km than 120 km in diameter. Future drilling projects should better constrain the level of erosion, and may reveal any preserved impact lithologies. 相似文献
304.
LEE CLAYTON JOHN W. ATTIG DAVID M. MICKELSON 《Boreas: An International Journal of Quaternary Research》2001,30(3):173-188
Pleistocene permafrost had a major but generally unappreciated effect on the landscape of Wisconsin, second only to glaciation. Evidence for continuous permafrost during the last part of the Wisconsin Glaciation includes ice-wedge casts seen both in outcrop (generally in gravel pits) and as polygonal networks (on aerial photographs). Other important evidence includes fossil tundra organisms. Other features that are probably the result of permafrost in Wisconsin include talus cones, block streams, solifluction rubble at the base of most hillslopes, fluvial cobble gravel, gullies that are today inactive, lake-ice collapse trenches, and ice-walled-lake plains. Permafrost caused accelerated regional erosion of the landscape; most topographic features formed before the last permafrost melted have been highly modified or even destroyed, whereas those formed after are much better preserved. In addition, the presence of permafrost influenced many glacial processes and landforms. Permafrost was present until about 14000 yr BP in the southern part of the state to about 10000 yr BP in the northern part. 相似文献
305.
306.
A. GENERAL DESCRIPTION This peridotite is collected from Ching Kuang Shan (青矿山), Hui Li Hsien (会理县), Szechuan Province Its colour is greenish black The texture is medium coarse grained. The cleavage surfaces of the amphibole 相似文献
307.
GEOLOGY OF THE GORGE DISTRICT OF THE YANGTZE (FROM ICHANG TO TZEKUEI) WITH SPECIAL REFERENCE TO THE DEVELOPMENT OF THE GORGES. 总被引:7,自引:0,他引:7
As the Gorge District of the Yangtze is one of the few areas in China that can deservedly boast before the world its scenic grandeur as well as beauty, it has been long felt that a systematic account of its geological conditions would open another aspect of interest to the scientific travellers. There are already on the record the observations of Pumpelly, Richthofen, Abendanon, Willis and Blackwelder, Noda and others; but the results of their work, important as they are in certain respects, seem to ind... 相似文献
308.
Little doubt can exist regarding the close affinity between Fusulina (MOLLER) and Schwagerina (MOLLER), though there is much room for discussion as to their genetic relation. The recognized affinity seems to depend rather on their common departure from other members of the family, for 相似文献
309.
Impact of Horizontal Resolution and Cumulus Parameterization Scheme on the Simulation of Heavy Rainfall Events over the Korean Peninsula 总被引:1,自引:0,他引:1
In this paper, we present the results from high-resolution numerical simulations of three heavy rainfall events over the Korean Peninsula. The numerical results show that the prediction accuracy for heavy rainfall events improved as horizontal resolution increased. The fine-grid precipitation fields were much closer to the real precipitation fields in the case of large synoptic forcing over the Korean Peninsula. In the case of large convective available potential energy and weak synoptic forcing, it seems that even when using a high resolution, the models still showed poor performance in reproducing the observed high precipitation amounts. However, activation of the cumulus parameterization scheme in the intermediate resolution of 9 km, even at a grid spacing of 3 km, had a positive impact on the simulation of the heavy rainfall event. 相似文献
310.
Late Quaternary glaciation in the Tianshan and implications for palaeoclimatic change: a review 总被引:1,自引:0,他引:1
XIANGKE XU AXEL KLEIDON LEE MILLER SHIQIN WANG LIQIANG WANG GUOCHENG DONG 《Boreas: An International Journal of Quaternary Research》2010,39(2):215-232
Xu, X., Kleidon, A., Miller, L., Wang, S., Wang, L. & Dong, G. 2009: Late Quaternary glaciation in the Tianshan and implications for palaeoclimatic change: a review. Boreas, 10.1111/j.1502‐3885.2009.00118.x. ISSN 0300‐9483. The Tianshan mountain range has been extensively and repeatedly glaciated during the late Quaternary. Multiple moraines in this region record the extent and timing of late Quaternary glacier fluctuations. The moraines and their ages are described in three sub‐regions: eastern, central and western Tianshan. Notable glacial advances occurred during marine oxygen isotope stages (MIS) 6, 4, 3, 2, the Neoglacial and the Little Ice Age (LIA) in these sub‐regions. Glaciers in western Tianshan advanced significantly also during MIS 5, but not in eastern and central Tianshan. The local last glacial maximum (llgm) of the three sub‐regions pre‐dated the Last Glacial Maximum (LGM) and occurred during MIS 4 in eastern and central Tianshan, but during MIS 3 in western Tianshan. The spatial and temporal distribution of the glaciers suggests that precipitation (as snow at high altitude) is the main factor controlling glacial advance in the Tianshan. The late Quaternary climate in the Tianshan has been generally cold–dry during glacial times and warm–humid during interglacial times. Between neighbouring glacial times, the climate has had a more arid tendency in eastern and central Tianshan. These palaeoclimatic conditions inferred from glacial landforms indicate important relationships between the mid‐latitude westerly, the Siberian High and the Asian monsoon. 相似文献