全文获取类型
收费全文 | 1475篇 |
免费 | 81篇 |
国内免费 | 25篇 |
专业分类
测绘学 | 31篇 |
大气科学 | 98篇 |
地球物理 | 440篇 |
地质学 | 475篇 |
海洋学 | 112篇 |
天文学 | 281篇 |
综合类 | 7篇 |
自然地理 | 137篇 |
出版年
2023年 | 4篇 |
2022年 | 6篇 |
2021年 | 26篇 |
2020年 | 34篇 |
2019年 | 24篇 |
2018年 | 43篇 |
2017年 | 38篇 |
2016年 | 53篇 |
2015年 | 54篇 |
2014年 | 45篇 |
2013年 | 83篇 |
2012年 | 74篇 |
2011年 | 82篇 |
2010年 | 64篇 |
2009年 | 91篇 |
2008年 | 93篇 |
2007年 | 83篇 |
2006年 | 68篇 |
2005年 | 66篇 |
2004年 | 72篇 |
2003年 | 44篇 |
2002年 | 45篇 |
2001年 | 31篇 |
2000年 | 21篇 |
1999年 | 20篇 |
1998年 | 28篇 |
1997年 | 15篇 |
1996年 | 19篇 |
1995年 | 10篇 |
1994年 | 10篇 |
1993年 | 14篇 |
1992年 | 14篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 8篇 |
1986年 | 13篇 |
1985年 | 18篇 |
1984年 | 12篇 |
1983年 | 22篇 |
1982年 | 19篇 |
1981年 | 9篇 |
1980年 | 12篇 |
1979年 | 15篇 |
1978年 | 10篇 |
1977年 | 9篇 |
1976年 | 6篇 |
1973年 | 4篇 |
1971年 | 3篇 |
排序方式: 共有1581条查询结果,搜索用时 234 毫秒
991.
992.
993.
The 2dF Galaxy Redshift Survey: correlation functions, peculiar velocities and the matter density of the Universe 总被引:1,自引:0,他引:1
Ed Hawkins Steve Maddox Shaun Cole Ofer Lahav Darren S. Madgwick Peder Norberg John A. Peacock Ivan K. Baldry Carlton M. Baugh Joss Bland-Hawthorn Terry Bridges Russell Cannon Matthew Colless Chris Collins Warrick Couch Gavin Dalton Roberto De Propris Simon P. Driver George Efstathiou Richard S. Ellis Carlos S. Frenk Karl Glazebrook Carole Jackson Bryn Jones Ian Lewis Stuart Lumsden Will Percival Bruce A. Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2003,346(1):78-96
994.
995.
996.
The status of laboratory spectroscopic data for exoplanet characterisation missions such as EChO is reviewed. For many molecules (eg H 2O, CO, CO 2, H\(_{3}^{+}\), O 2, O 3) the data are already available. For the other species work is actively in progress constructing this data. Much of the is work is being undertaken by ExoMol project (www.?exomol.?com). This information can be used to construct a mission-specific spectroscopic database. 相似文献
997.
Jeremie Vaubaillon Pavel Koten Anastasios Margonis Juraj Toth Regina Rudawska Maria Gritsevich Joe Zender Jonathan McAuliffe Pierre-Dominique Pautet Peter Jenniskens Detlef Koschny Francois Colas Sylvain Bouley Lucie Maquet Arnaud Leroy Jean Lecacheux Jiri Borovicka Junichi Watanabe Jürgen Oberst 《Earth, Moon, and Planets》2015,114(3-4):137-157
998.
P. J. Wozniakiewicz M. C. Price S. P. Armes M. J. Burchell M. J. Cole L. A. Fielding J. K. Hillier J. R. Lovett 《Meteoritics & planetary science》2014,49(10):1929-1947
The interstellar collector on NASA's Stardust mission captured many particles from sources other than the interstellar dust stream. Impact trajectory may provide a means of discriminating between these different sources, and thus identifying/eliminating candidate interstellar particles. The collector's aerogel preserved a clear record of particle impact trajectory from the inclination and direction of the resultant tracks. However, the collector also contained aluminum foils and, although impact crater studies to date suggest only the most inclined impacts (>45° from normal) produce crater morphologies that indicate trajectory (i.e., distinctly elliptical), these studies have been restricted to much larger (mm and above) scales than are relevant for Stardust (μm). It is unknown how oblique impact crater morphology varies as a function of length scale, and therefore how well Stardust craters preserve details of impactor trajectory. Here, we present data from a series of impact experiments, together with complementary hydrocode modeling, that examine how crater morphology changes with impact angles for different‐sized projectiles. We find that, for our smallest spherical projectiles (2 μm diameter), the ellipticity and rim morphology provide evidence of their inclined trajectory from as little as 15° from normal incidence. This is most likely a result of strain rate hardening in the target metal. Further experiments and models find that variation in velocity and impactor shape complicate these trends, but that rim morphology remains useful in determining impact direction (where the angle of impact is >20° from normal) and may help identify candidate interstellar particle craters on the Stardust collector. 相似文献
999.
This paper outlines evidence from Pakefield (northern Suffolk), eastern England, for sea‐level changes, river activity, soil development and glaciation during the late Early and early Middle Pleistocene (MIS 20–12) within the western margins of the southern North Sea Basin. During this time period, the area consisted of a low‐lying coastal plain and a shallow offshore shelf. The area was drained by major river systems including the Thames and Bytham. Changes in sea‐level caused several major transgressive–regressive cycles across this low‐relief region, and these changes are identified by the stratigraphic relationship between shallow marine (Wroxham Crag Formation), fluvial (Cromer Forest‐bed and Bytham formations) and glacial (Happisburgh and Lowestoft formations) sediments. Two separate glaciations are recognised—the Happisburgh (MIS 16) and Anglian (MIS 12) glaciations, and these are separated by a high sea level represented by a new member of the Wroxham Crag Formation, and several phases of river aggradation and incision. The principal driving mechanism behind sea‐level changes and river terrace development within the region during this time period is solar insolation operating over 100‐kyr eccentricity cycles. This effect is achieved by the impact of cold climate processes upon coastal, river and glacial systems and these climatically forced processes obscure the neotectonic drivers that operated over this period of time. © British Geological Survey/Natural Environment Research Council copyright 2005. Reproduced with the permission of BGS/NERC. Published by John Wiley & Sons, Ltd. 相似文献
1000.
Vivienne Wild John A. Peacock Ofer Lahav Edward Conway Steve Maddox Ivan K. Baldry Carlton M. Baugh Joss Bland-Hawthorn Terry Bridges Russell Cannon Shaun Cole Matthew Colless Chris Collins Warrick Couch Gavin Dalton Roberto De Propris Simon P. Driver George Efstathiou Richard S. Ellis Carlos S. Frenk Karl Glazebrook Carole Jackson Ian Lewis Stuart Lumsden Darren Madgwick Peder Norberg Bruce A. Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2005,356(1):247-269