全文获取类型
收费全文 | 3289篇 |
免费 | 23篇 |
国内免费 | 13篇 |
专业分类
航空 | 1594篇 |
航天技术 | 1152篇 |
综合类 | 4篇 |
航天 | 575篇 |
出版年
2021年 | 26篇 |
2019年 | 23篇 |
2018年 | 54篇 |
2017年 | 51篇 |
2016年 | 45篇 |
2015年 | 26篇 |
2014年 | 71篇 |
2013年 | 91篇 |
2012年 | 84篇 |
2011年 | 119篇 |
2010年 | 80篇 |
2009年 | 140篇 |
2008年 | 156篇 |
2007年 | 99篇 |
2006年 | 71篇 |
2005年 | 93篇 |
2004年 | 90篇 |
2003年 | 101篇 |
2002年 | 73篇 |
2001年 | 117篇 |
2000年 | 66篇 |
1999年 | 69篇 |
1998年 | 87篇 |
1997年 | 59篇 |
1996年 | 93篇 |
1995年 | 112篇 |
1994年 | 111篇 |
1993年 | 50篇 |
1992年 | 73篇 |
1991年 | 34篇 |
1990年 | 32篇 |
1989年 | 79篇 |
1988年 | 28篇 |
1987年 | 25篇 |
1986年 | 33篇 |
1985年 | 90篇 |
1984年 | 90篇 |
1983年 | 67篇 |
1982年 | 66篇 |
1981年 | 101篇 |
1980年 | 19篇 |
1979年 | 25篇 |
1978年 | 29篇 |
1977年 | 28篇 |
1975年 | 30篇 |
1974年 | 23篇 |
1973年 | 21篇 |
1972年 | 20篇 |
1969年 | 20篇 |
1968年 | 21篇 |
排序方式: 共有3325条查询结果,搜索用时 218 毫秒
151.
B. Rizk C. Drouet dAubigny C.W. Hergenrother B.J. Bos D.R. Golish R. Malhotra D.S. Lauretta J. Butt J. Patel M. Fitzgibbon C. May E.B. Bierhaus S. Freund M. Fisher S. Cambioni C.A. Bennett S.S. Balram-Knutson K. Harshman M. Moreau 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(1):672-691
We analyzed high-angular rate streaks first recorded by OSIRIS-REx’s MapCam during a 2017 search for Earth Trojan asteroids. We interpret them as water-ice particles that translated across the imager’s field of view, originating from the spacecraft itself. Their translation velocities approximated 0.1–1?m/s based on reasonable conclusions about their range. Pursuing several lines of investigation to seek a coherent hypothesis, we conclude that the episodic releases of the water ice particles are associated with spacecraft attitudes that resulted in solar illumination of previously shadowed regions. This correlation suggests that the OSIRIS-REx spacecraft itself possesses micro-climatic zones consisting of hot regions and cold traps that may temporarily potentially pass volatiles back and forth before losing most of them. 相似文献
152.
An exact solution of the Navier - Stokes equations is given that describes the vorticity of a viscous incompressible liquid or gas, dissipative mediums, stationary shear counter-current of continuous vortical medium in the absence of the Coriolis field. 相似文献
153.
154.
The DB-8 detectors of the ISS radiation monitoring system (RMS) have operated almost continuously onboard the ISS service module since August 2001 till December 2014. The RMS data obtained were used for the daily monitoring of the radiation environment aboard the station. This paper considers the technique of RMS data analysis that allows one to distinguish the contributions of galactic cosmic rays and the Earth’s inner radiation belt to the daily dose based on the dosimetry data obtained as a result of the station’s passage in areas of the highest geomagnetic latitudes. The paper presents the results of an analysis of the dosimetry data based on this technique for 2005–2011, as well as a comparison with similar results the authors obtained previously using the technique based on an analysis of the dosimetry data obtained during station passages in the area of the South Atlantic Anomaly. 相似文献
155.
V. A. Kudinov A. V. Eremin A. E. Kuznetsova E. V. Stefanyuk 《Russian Aeronautics (Iz VUZ)》2014,57(1):37-44
An exact analytical solution of the thermoelasticity problem is presented for a multilayer shallow cylinder with physical properties of the medium that are constant in the limits of each layer. The effect of thermal shock of different intensity as well as the penetration depth of thermal disturbance on the distribution of radial and circumferential thermal stresses has been studied as applied to the one- and two-layer cylinder. It has been shown that the circumferential compressive stresses appear on the external surface of the cylinder under thermal shock while the tensile stresses appear on the internal surface. 相似文献
156.
157.
158.
159.
E. O. Ariskin A. V. Nikitin V. V. Soldatkin V. M. Soldatkin 《Russian Aeronautics (Iz VUZ)》2015,58(4):454-460
The problem and features of measuring the speed and the direction angle of the wind vector relative to the longitudinal helicopter axis during parking, starting and takeoff-landing modes by onboard means are considered. The construction principles, information processing algorithms and advantages of onboard system for measuring the wind vector parameters based on ion-beacon and aerometric measuring channels, are disclosed. 相似文献
160.
This paper presents the results of analyzing the shaping of thin-walled conical parts with the uniform thickness along generatrix. 相似文献