全文获取类型
收费全文 | 1408篇 |
免费 | 41篇 |
国内免费 | 8篇 |
专业分类
测绘学 | 17篇 |
大气科学 | 140篇 |
地球物理 | 297篇 |
地质学 | 473篇 |
海洋学 | 100篇 |
天文学 | 285篇 |
综合类 | 3篇 |
自然地理 | 142篇 |
出版年
2021年 | 11篇 |
2020年 | 15篇 |
2019年 | 21篇 |
2018年 | 30篇 |
2017年 | 39篇 |
2016年 | 30篇 |
2015年 | 28篇 |
2014年 | 29篇 |
2013年 | 72篇 |
2012年 | 30篇 |
2011年 | 39篇 |
2010年 | 29篇 |
2009年 | 68篇 |
2008年 | 58篇 |
2007年 | 54篇 |
2006年 | 51篇 |
2005年 | 46篇 |
2004年 | 56篇 |
2003年 | 49篇 |
2002年 | 56篇 |
2001年 | 44篇 |
2000年 | 40篇 |
1999年 | 19篇 |
1998年 | 33篇 |
1997年 | 17篇 |
1996年 | 19篇 |
1995年 | 21篇 |
1994年 | 21篇 |
1993年 | 17篇 |
1992年 | 12篇 |
1991年 | 13篇 |
1990年 | 16篇 |
1989年 | 15篇 |
1988年 | 16篇 |
1987年 | 19篇 |
1986年 | 24篇 |
1985年 | 23篇 |
1984年 | 15篇 |
1983年 | 28篇 |
1982年 | 26篇 |
1981年 | 25篇 |
1980年 | 26篇 |
1979年 | 18篇 |
1978年 | 11篇 |
1977年 | 12篇 |
1976年 | 17篇 |
1975年 | 13篇 |
1974年 | 12篇 |
1973年 | 12篇 |
1971年 | 11篇 |
排序方式: 共有1457条查询结果,搜索用时 15 毫秒
141.
Robert A. Watson Pedro Carreira Kieran Cleary Rod D. Davies Richard J. Davis Clive Dickinson Keith Grainge † Carlos M. Gutiérrez Michael P. Hobson Michael E. Jones Rüdiger Kneissl Anthony Lasenby Klaus Maisinger Guy G. Pooley Rafael Rebolo José Alberto Rubiño-Martin ‡ Ben Rusholme § Richard D. E. Saunders Richard Savage Paul F. Scott Ane Slosar Pedro J. Sosa Molina Angela C. Taylor David Titterington Elizabeth Waldram Althea Wilkinson 《Monthly notices of the Royal Astronomical Society》2003,341(4):1057-1065
142.
143.
A constitutive model is described for the prediction of dynamic crack formation in geological media. The model includes a simple tensile failure criterion for crack formation and a soil plasticity model for both deviatoric and volumetric plasticity. Numerical results are presented which show that the model reproduces the observed dependence of fracture formation on loding rate for dynamic pressure loading of boreholes. The use of the model as a numerical tool for design is demonstrated through two example parameter studies. 相似文献
144.
Notice
The European Geosciences Union General Assembly Vienna, Austria, 25–29 April 2005Basic Studies of the Atmospheric and Oceanic Boundary Layers 相似文献145.
Harold E. Taylor 《Solar physics》1969,6(2):320-334
The magnetic field measurements made by the magnetic field experiment on the IMP 3 (Explorer 28) spacecraft have been examined at the time of geomagnetic s.s.c. events. Thirty-six such events occurred while IMP 3 was in the interplanetary medium during 1965, 1966 and 1967 and have been analysed. Of these events 8 must have been tangential discontinuities, 2 are either tangential discontinuities or rotational discontinuities and 26 are possible shock waves. (Two of these 26 events have been shown by other authors to be shocks.) These 26 possible shocks have similar magnetic signatures: an increase of 20 % or more in the magnetic field magnitude and a relatively small (always less than 90°) change in direction. The larger s.s.c. events were more likely to be caused by possible shocks while the smaller events were often associated with tangential discontinuities. The orientation of the discontinuity surfaces of the 26 possible shocks shows a preference to be aligned somewhere between a direction perpendicular to the sun-earth line and a direction tangent to the local spiral angle of the magnetic field. It was possible to associate solar flares with 14 of the 26 possible shock events. Of these 14, a reliable orientation was deduced for 8 events. By considering the orientation of these 8 events in relation to the position of the parent flares on the solar disk it is suggested that a typical shock front propagating out from the sun has a radius of curvature less than but of the order of 1 AU.NAS/NRC Postdoctoral Resident Research Associate. 相似文献
146.
147.
Tom S. White Mark J. White Andy J. Howard 《Proceedings of the Geologists' Association. Geologists' Association》2009,120(4):223-232
A brief history is presented here of the activities of the three most notable collectors of Lower and Middle Palaeolithic artefacts from Quaternary river terrace deposits in the Trent Valley, derived from archival material that has been largely ignored by previous research. Two, Mr. Fred W.G. Davey and Mr. George F. Turton, were local amateur collectors who did not publish the results of their work themselves and were reliant on collaboration with established archaeologists. The third, Mr. A. Leslie Armstrong, was an archaeologist best known for his work at Creswell Crags and Grimes Graves. Armstrong also made many Palaeolithic discoveries in the Trent Valley but published few details of his own material. Although such details of early Palaeolithic research in the Midlands and North of Britain are predominantly of historical interest only, they nonetheless provide a number of insights into the apparent lack of interest shown in areas north of the ‘Severn-Wash Line’ by collectors of Palaeolithic artefacts. Importantly, the dataset assembled by the Trent Valley Palaeolithic Project (TVPP) and summarized here is the only complete record of the known artefacts and archival material from the Trent, a proportion of which is now unavailable to the research community, having entered unknown private ownership since being studied. The second part of the paper relates this early research to current knowledge of the British Palaeolithic at its most northern fringes and to recent developments in reconstructing the Quaternary evolution of the River Trent. 相似文献
148.
149.
150.
S. Johnston R. Taylor M. Bailes N. Bartel C. Baugh M. Bietenholz C. Blake R. Braun J. Brown S. Chatterjee J. Darling A. Deller R. Dodson P. Edwards R. Ekers S. Ellingsen I. Feain B. Gaensler M. Haverkorn G. Hobbs A. Hopkins C. Jackson C. James G. Joncas V. Kaspi V. Kilborn B. Koribalski R. Kothes T. Landecker A. Lenc J. Lovell J.-P. Macquart R. Manchester D. Matthews N. McClure-Griffiths R. Norris U.-L. Pen C. Phillips C. Power R. Protheroe E. Sadler B. Schmidt I. Stairs L. Staveley-Smith J. Stil S. Tingay A. Tzioumis M. Walker J. Wall M. Wolleben 《Experimental Astronomy》2008,22(3):151-273