全文获取类型
收费全文 | 5432篇 |
免费 | 50篇 |
国内免费 | 16篇 |
专业分类
航空 | 2651篇 |
航天技术 | 1658篇 |
综合类 | 34篇 |
航天 | 1155篇 |
出版年
2021年 | 56篇 |
2019年 | 32篇 |
2018年 | 213篇 |
2017年 | 170篇 |
2016年 | 103篇 |
2015年 | 62篇 |
2014年 | 142篇 |
2013年 | 145篇 |
2012年 | 174篇 |
2011年 | 310篇 |
2010年 | 228篇 |
2009年 | 326篇 |
2008年 | 363篇 |
2007年 | 229篇 |
2006年 | 115篇 |
2005年 | 182篇 |
2004年 | 137篇 |
2003年 | 175篇 |
2002年 | 105篇 |
2001年 | 164篇 |
2000年 | 80篇 |
1999年 | 109篇 |
1998年 | 121篇 |
1997年 | 87篇 |
1996年 | 92篇 |
1995年 | 128篇 |
1994年 | 124篇 |
1993年 | 69篇 |
1992年 | 100篇 |
1991年 | 53篇 |
1990年 | 37篇 |
1989年 | 88篇 |
1988年 | 40篇 |
1987年 | 42篇 |
1986年 | 36篇 |
1985年 | 102篇 |
1984年 | 87篇 |
1983年 | 78篇 |
1982年 | 88篇 |
1981年 | 122篇 |
1980年 | 41篇 |
1979年 | 36篇 |
1978年 | 32篇 |
1977年 | 25篇 |
1976年 | 29篇 |
1975年 | 22篇 |
1974年 | 23篇 |
1973年 | 23篇 |
1972年 | 23篇 |
1971年 | 21篇 |
排序方式: 共有5498条查询结果,搜索用时 15 毫秒
51.
F. S. Khairullin 《Russian Aeronautics (Iz VUZ)》2009,52(4):480-483
We consider a possibility to apply the method of analyzing the complex-shaped shells, proposed in [1], for determining the
stress strain state of thin shells with a degenerating domain. The results of numerical calculations are presented. 相似文献
52.
A. Sh. Dzhabrailov Yu. V. Klochkov S. S. Marchenko A. P. Nikolaev 《Russian Aeronautics (Iz VUZ)》2007,50(2):115-120
We demonstrate that it is possible to express each component of the displacement vector for the interior point of the finite element (FE) through all components of nodal unknowns in curvilinear coordinates. The effectiveness of the valid technique of vector approximation for displacement fields has been verified on an example. 相似文献
53.
The fastest pulsar and the slowest nova; the oldest galaxies and the youngest stars; the weirdest life forms and the commonest
dwarfs; the highest energy particles and the lowest energy photons. These were some of the extremes of Astrophysics 2006.
We attempt also to bring you updates on things of which there is currently only one (habitable planets, the Sun, and the Universe)
and others of which there are always many, like meteors and molecules, black holes and binaries. 相似文献
54.
N. N. Makarov 《Russian Aeronautics (Iz VUZ)》2008,51(1):60-66
The problem is formulated and a technique is revealed for synthesizing the optimal strategy of troubleshooting and constructing an operation algorithm for the information-control system of inspection and diagnostics of the aircraft equipment state. 相似文献
55.
The characteristics of the insulator wear process in the discharge chamber of a stationary plasma thruster (SPT) are analyzed. The results of studying the erosion resistance to ionic spraying of different ceramic compositions are presented. It is shown experimentally that the integral characteristics (the value of thrust and thrust efficiency) as well as the SPT lifetime can be improved in changing from the conventional hot-pressed boron silicate (BN + SiO2) ceramics to the BN + Si3N4 ceramic compositions. 相似文献
56.
V. A. Ovchinnikov 《Russian Aeronautics (Iz VUZ)》2007,50(2):146-149
We analyze the effect of injection both of uniformly distributed over the entire cylinder surface and of the optimal one on the velocity distribution at the outer border of the boundary layer and, as a result, on friction. 相似文献
57.
The results of studying an incompressible gas flow field in a periodic element of the porous structure made up of the same radius spheres are presented; the studies were based on the solution of the Navier-Stokes equations using FLUENT software. The possibilities to accelerate the solution process with the use of parallel calculations are investigated and the calculation results under changes of pressure differential in the periodic element are given. 相似文献
58.
T. Yu. Gainutdinova 《Russian Aeronautics (Iz VUZ)》2007,50(2):215-217
In this paper, a program package for solving problems in the field of thin-walled three-dimensional FV structure design is described. 相似文献
59.
A. I. Belousov S. V. Falaleev A. S. Vinogradov P. V. Bondarchuk 《Russian Aeronautics (Iz VUZ)》2007,50(4):390-394
Problems arising in introduction of gasodynamic seals in aircraft engines are considered. The operation of a face gasodynamic seal as part of a natural gas pump is analyzed and its efficiency in the presence of oil is shown. 相似文献
60.
A system for measuring the altitude-airspeed parameters of rotorcraft and very light flight vehicles
In this paper, a problem on measuring the altitude-airspeed parameters (AAPs) of rotorcraft and very light flight vehicles is considered. Some ways of improving systems used to measure the parameters of FV elements and units have been determined. Also suggested and substantiated are the principles and designs of the basic variants of these measuring systems as well as the algorithms of their operation. 相似文献