全文获取类型
收费全文 | 6852篇 |
免费 | 16篇 |
国内免费 | 20篇 |
专业分类
航空 | 3067篇 |
航天技术 | 2406篇 |
综合类 | 21篇 |
航天 | 1394篇 |
出版年
2021年 | 74篇 |
2019年 | 45篇 |
2018年 | 160篇 |
2017年 | 107篇 |
2016年 | 112篇 |
2015年 | 51篇 |
2014年 | 178篇 |
2013年 | 222篇 |
2012年 | 212篇 |
2011年 | 322篇 |
2010年 | 229篇 |
2009年 | 329篇 |
2008年 | 367篇 |
2007年 | 220篇 |
2006年 | 156篇 |
2005年 | 185篇 |
2004年 | 182篇 |
2003年 | 205篇 |
2002年 | 145篇 |
2001年 | 218篇 |
2000年 | 127篇 |
1999年 | 162篇 |
1998年 | 190篇 |
1997年 | 109篇 |
1996年 | 171篇 |
1995年 | 203篇 |
1994年 | 189篇 |
1993年 | 120篇 |
1992年 | 149篇 |
1991年 | 47篇 |
1990年 | 48篇 |
1989年 | 139篇 |
1988年 | 59篇 |
1987年 | 56篇 |
1986年 | 63篇 |
1985年 | 183篇 |
1984年 | 144篇 |
1983年 | 107篇 |
1982年 | 115篇 |
1981年 | 214篇 |
1980年 | 49篇 |
1979年 | 45篇 |
1978年 | 50篇 |
1977年 | 42篇 |
1975年 | 50篇 |
1974年 | 38篇 |
1973年 | 32篇 |
1972年 | 35篇 |
1971年 | 35篇 |
1970年 | 37篇 |
排序方式: 共有6888条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
V. A. Sadovnichiy A. M. Amelyushkin V. Angelopoulos V. V. Bengin V. V. Bogomolov G. K. Garipov E. S. Gorbovskoy B. Grossan P. A. Klimov B. A. Khrenov J. Lee V. M. Lipunov G. W. Na M. I. Panasyuk I. H. Park V. L. Petrov C. T. Russell S. I. Svertilov E. A. Sigaeva G. F. Smoot Yu. Shprits N. N. Vedenkin I. V. Yashin 《Cosmic Research》2013,51(6):427-433
At present, the Institute of Nuclear Physics of Moscow State University, in cooperation with other organizations, is preparing space experiments onboard the Lomonosov satellite. The main goal of this mission is to study extreme astrophysical phenomena such as cosmic gamma-ray bursts and ultra-high-energy cosmic rays. These phenomena are associated with the processes occurring in the early universe in very distant astrophysical objects, therefore, they can provide information on the first stages of the evolution of the universe. This paper considers the main characteristics of the scientific equipment aboard the Lomonosov satellite. 相似文献
105.
106.
L. M. Zelenyi M. S. Dolgonosov A. A. Bykov V. Yu. Popov Kh. V. Malova 《Cosmic Research》2002,40(4):357-366
Using both analytical and numerical models of the collisionless anisotropic current sheet generated by the impinging flows of transient ions, we have studied the self-consistent solutions taking the plasma trapped in the sheet into account. It is demonstrated that there exists a limited window in the space of system parameters where self-consistent solutions can exist. When the density of the quasi-trapped plasma is sufficiently large, a redistribution of the total current can be a cause of the sheet decay, when the local current of the trapped particles compensate (totally or in part) the main current in the center and at the edges of the sheet, while the total current generated by ions on the trapped trajectories vanishes. 相似文献
107.
The motion of a variable-mass spacecraft is considered in the powered section of a descending trajectory. Approximate analytical solutions are obtained for the angles of spatial orientation of the spacecraft, which allows one to analyze the nutation motion and to develop recommendations on the spacecraft’s mass configuration, providing the smallest possible deviations of the longitudinal axis and thrust vector from specified directions. The errors of stabilization of the spacecraft’s longitudinal axis are calculated by means of numerical integration of complete models and using the obtained analytical solutions, the results being in good agreement. 相似文献
108.
L. G. Blomberg J. A. Cumnock 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2004,33(12):2161-2165
Mercury has a small but intriguing magnetosphere. In this brief review, we discuss some similarities and differences between Mercury’s and Earth’s magnetospheres. In particular, we discuss how electric and magnetic field measurements can be used as a diagnostic tool to improve our understanding of the dynamics of Mercury’s magnetosphere. These points are of interest to the upcoming ESA-JAXA BepiColombo mission to Mercury. 相似文献
109.
R. A. Valitov 《Russian Aeronautics (Iz VUZ)》2012,55(1):95-100
A problem is posed and solved on determining the optimal parameters of a moving wall installed on the airfoil surface to prevent the boundary layer separation. As the wall parameters, its initial and final position and motion velocity are taken. To solve the problem, the optimization methods with penalty functions are used. The conclusions were drawn on selecting the efficient parameters of the moving wall in terms of the minimum of energy expenditure and friction drag. 相似文献
110.
In this paper, the results of an experimental study concerning average heat transfer in an annular channel with flow swirling by an endless screw and spherical grooves on the convex surface are presented. Also analyzed is the heat and hydraulic efficiency of grooves application under conditions being considered. 相似文献