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Jeffrey Turner Hans‐Jrgen Albrechtsen Mike Bonell Jean‐Pierre Duguet Bob Harris Rainer Meckenstock Kevin McGuire Roger Moussa Norman Peters Hans H. Richnow Barbara Sherwood‐Lollar Stefan Uhlenbrook Henny van Lanen 《水文研究》2006,20(1):205-213
A summary is provided of the first of a series of proposed Integrated Science Initiative workshops supported by the UNESCO International Hydrological Programme. The workshop brought together hydrologists, environmental chemists, microbiologists, stable isotope specialists and natural resource managers with the purpose of communicating new ideas on ways to assess microbial degradation processes and reactive transport at catchment scales. The focus was on diffuse contamination at catchment scales and the application of compound‐specific isotope analysis (CSIA) in the assessment of biological degradation processes of agrochemicals. Major outcomes were identifying the linkage between water residence time distribution and rates of contaminant degradation, identifying the need for better information on compound specific microbial degradation isotope fractionation factors and the potential of CSIA in identifying key degradative processes. In the natural resource management context, a framework was developed where CSIA techniques were identified as practically unique in their capacity to serve as distributed integrating indicators of process across a range of scales (micro to diffuse) of relevance to the problem of diffuse pollution assessment. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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A revised typology of Australian tropical rivers was applied to the complete channel network (named and major rivers) shown on 1:250 000 topographic maps for three large drainage basins in northern Australia (Daly River, NT; Fitzroy River, WA; Flinders River, Qld). Reach mapping and classification were conducted using the revised typology. The 12 major river types proposed were: (1) bedrock rivers; (2) bedrock‐confined and ‐constrained rivers; (3) low sinuosity (straight) rivers; (4) meandering rivers; (5) wandering rivers; (6) anabranching rivers; (7) chains of ponds; (8) gullies; (9) floodouts; (10) lakes, swamps, billabongs and wetlands; (11) non‐channelized valley floors; and (12) estuarine rivers. The 12 major river types were developed based on river reach mapping for more than 264 000 km2 of tropical Australian catchments. At scales larger than 1:250 000, subdivision of each major river type is recommended. In the Daly and Fitzroy catchments, confined and constrained rivers dominate, whereas in the Flinders and Fitzroy catchments, anabranching rivers dominate. The dominant river types need benchmarking with adequate numbers of control reaches so that channel changes induced by human and natural impacts can be measured by reference to the stability of these controls. Wandering rivers, floodouts and non‐channelized valley floors were rare for the 1:250 000 channel network in northern Australia but need inclusion in national parks. 相似文献
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Bigg Grant R. Cropper T. E. O’Neill Clare K. Arnold Alex K. Fleming A. H. Marsh R. Ivchenko V. Fournier Nicolas Osborne Mike Stephens Robin 《Natural Hazards》2018,92(2):1113-1136
Natural Hazards - With the polar regions opening up to more marine activities but iceberg numbers more likely to increase than decline as a result of global warming, the risk from icebergs to... 相似文献
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We performed measurements using an SO2 imaging camera of the SO2 gas mass emitted during five discrete explosive events on Stromboli volcano on 3 October 2006. The SO2 gas mass released during discrete explosions was 15–40 kg per explosion, producing 3–8% of the total daily SO2 gas emission, demonstrating that in terms of gas flux Strombolian explosions are a second-order phenomenon compared with quiescent degassing. Using the typical gas composition measured with OP-FTIR allows us to determine the total gas mass released during an explosion as 360–960 kg with a volume of 1500–4100 m3 at 1 bar. At the probable source pressure of gas slug formation of 75 MPa this gas amount would occupy a volume equivalent to a sphere with a radius of 0.8–1 m, comparable with estimates of Stromboli's conduit geometry. 相似文献
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The production of rock aggregates for construction is the largest of the extractive industries in Britain. Natural aggregates form the main component, by volume, in the manufacture of concrete but the part played by aggregates in the durability and performance aspects of concrete is still only moderately understood. This feature summarizes the main characteristics of common aggregate in concrete, especially those leading to cracking and deterioration. Physical and mechanical causes of concrete cracking are of immense importance but are omitted from the following. The feature expands on the earlier one: ‘Concrete: a man‐made rock?’ (Geology Today, 2010, v.26, n.2). To follow is another that will continue the story by looking at chemical reactivity in concretes. 相似文献