全文获取类型
收费全文 | 806篇 |
免费 | 33篇 |
国内免费 | 4篇 |
专业分类
测绘学 | 5篇 |
大气科学 | 80篇 |
地球物理 | 153篇 |
地质学 | 255篇 |
海洋学 | 53篇 |
天文学 | 236篇 |
综合类 | 3篇 |
自然地理 | 58篇 |
出版年
2021年 | 5篇 |
2020年 | 6篇 |
2019年 | 11篇 |
2018年 | 26篇 |
2017年 | 16篇 |
2016年 | 12篇 |
2015年 | 28篇 |
2014年 | 22篇 |
2013年 | 47篇 |
2012年 | 22篇 |
2011年 | 42篇 |
2010年 | 41篇 |
2009年 | 51篇 |
2008年 | 26篇 |
2007年 | 33篇 |
2006年 | 30篇 |
2005年 | 31篇 |
2004年 | 26篇 |
2003年 | 26篇 |
2002年 | 32篇 |
2001年 | 19篇 |
2000年 | 32篇 |
1999年 | 9篇 |
1998年 | 14篇 |
1997年 | 15篇 |
1996年 | 15篇 |
1995年 | 19篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 10篇 |
1988年 | 3篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 10篇 |
1984年 | 13篇 |
1983年 | 11篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 8篇 |
1977年 | 11篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1974年 | 6篇 |
1973年 | 3篇 |
1971年 | 3篇 |
排序方式: 共有843条查询结果,搜索用时 390 毫秒
101.
102.
William S. Burgett Michael M. Vick David S. Davis Matthew Colless Roberto De Propris Ivan Baldry Carlton Baugh Joss Bland-Hawthorn Terry Bridges Russell Cannon Shaun Cole Chris Collins Warrick Couch Nicholas Cross Gavin Dalton Simon Driver George Efstathiou Richard Ellis Carlos S. Frenk Karl Glazebrook Edward Hawkins Carole Jackson Ofer Lahav Ian Lewis Stuart Lumsden Steve Maddox Darren Madgwick Peder Norberg John A. Peacock Will Percival Bruce Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2004,352(2):605-654
103.
104.
105.
Paul J. Coleman Jr. G. Schubert C. T. Russell L. R. Sharp 《Earth, Moon, and Planets》1972,4(3-4):419-429
A preliminary analysis of the data from the UCLA magnetometer on board the Apollo 15 subsatellite indicates that remnant magnetization is a characteristic property of the Moon, that its distribution is such as to produce a rather complex pattern or fine structure, and that a detailed mapping of its distribution is feasible with the present experiment. The analysis also shows that lunar induction fields produced by transients in the interplanetary magnetic field are detectable at the satellite orbit so that in principle the magnetometer data can be used to determine the latitudinal and longitudinal as well as radial dependences of the distribution of electrical conductivity within the Moon. Finally, the analysis indicates that the plasma void or diamagnetic cavity which forms behind the Moon when the Moon is in the solar wind, is detectable at the satellite's orbit and that the flow of the solar wind near the limbs is usually rather strongly disturbed.Publication No. 981. Institute of Geophysics and Planetary Physics. 相似文献
106.
Russell Cannon 《Astrophysics and Space Science》1989,160(1-2):275-280
Many of the major British telescopes are described in this volume by other speakers directly involved with those facilities, so this contribution will concentrate on aspects of the operation of the Anglo-Australian Observatory (AAO) which seem particularly relevant to the JNLT. Some requirements for the success of the new very large optical telescopes are also discussed.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988. 相似文献
107.
108.
We observed Saturn at far-infrared and submillimeter wavelengths during the Earth's March 1980 passage through the plane of Saturn's rings. Comparison with earlier spectroscopic observations by D. B. Ward [Icarus32, 437–442 (1977)], obtained at a time when the tilt angle of the rings was 21.8°, permits separation of the disk and ring contributions to the flux observed in this wavelength range. We present two main results: (1) The observed emission of the disk between 60 and 180 μm corresponds to a brightness temperature of 104 ± 2°K; (2) the brightness temperature of the rings drops approximately 20°K between 60 and 80 μm. Our data, in conjunction with the data obtained by other observers between 1 μm and 1 mm, permit us to derive an improved estimate for the total Saturnian surface brightness of (4.84 ± 0.32) × 10?4W cm?2 corresponding to an effective temperature of 96.1 ± 1.6°K. The ratio of radiated to incident power, PR/PI, is (1.46 ± 0.08)/(1 - A), where A is the Bond albedo. For A = 0.337 ± 0.029, PR/PI = 2.20 ± 0.15 and Saturn's intrinsic luminosity is LS = (2.9 ± 0.5) × 10?10L⊙. 相似文献
109.
110.
On 16 June 1972, the Naval Research Laboratory's coronagraph aboard OSO-7 tracked a huge coronal cloud moving outward from the Sun. Concurrent observations of the inner corona made by the High Altitude Observatory at Mauna Loa showed bifurcation of the underlying coronal structure. Together, these observations can be interpreted as evidence for the stretching of the closed fields into a magnetic bottle, extending to at least eight radii from the center of the Sun. 相似文献