全文获取类型
收费全文 | 1990篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
航空 | 986篇 |
航天技术 | 368篇 |
综合类 | 2篇 |
航天 | 637篇 |
出版年
2022年 | 5篇 |
2021年 | 22篇 |
2019年 | 9篇 |
2018年 | 170篇 |
2017年 | 149篇 |
2016年 | 48篇 |
2015年 | 31篇 |
2014年 | 36篇 |
2013年 | 48篇 |
2012年 | 75篇 |
2011年 | 167篇 |
2010年 | 152篇 |
2009年 | 182篇 |
2008年 | 158篇 |
2007年 | 156篇 |
2006年 | 22篇 |
2005年 | 78篇 |
2004年 | 37篇 |
2003年 | 28篇 |
2002年 | 20篇 |
2001年 | 39篇 |
2000年 | 21篇 |
1999年 | 12篇 |
1998年 | 27篇 |
1997年 | 11篇 |
1996年 | 21篇 |
1995年 | 18篇 |
1994年 | 26篇 |
1993年 | 15篇 |
1992年 | 18篇 |
1991年 | 4篇 |
1989年 | 14篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 3篇 |
1985年 | 26篇 |
1984年 | 18篇 |
1983年 | 10篇 |
1982年 | 11篇 |
1981年 | 16篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1974年 | 8篇 |
1972年 | 8篇 |
1968年 | 6篇 |
1967年 | 5篇 |
1966年 | 5篇 |
排序方式: 共有1993条查询结果,搜索用时 46 毫秒
441.
R.A. Gowen A. Smith A.D. Fortes S. Barber P. Brown P. Church G. Collinson A.J. Coates G. Collins I.A. Crawford V. Dehant J. Chela-Flores A.D. Griffiths P.M. Grindrod L.I. Gurvits A. Hagermann H. Hussmann R. Jaumann A.P. Jones K.H. Joy O. Karatekin K. Miljkovic E. Palomba W.T. Pike O. Prieto-Ballesteros F. Raulin M.A. Sephton S. Sheridan M. Sims M.C. Storrie-Lombardi R. Ambrosi J. Fielding G. Fraser Y. Gao G.H. Jones G. Kargl W.J. Karl A. Macagnano A. Mukherjee J.P. Muller A. Phipps D. Pullan L. Richter F. Sohl J. Snape J. Sykes N. Wells 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
442.
An approach to the analysis of electric arc process stability in plasma systems of ignition is considered depending on the
ignition system power circuit parameters, speed of plasma-generating air, and combustion chamber inlet pressure. Also solved
is the problem on determination of the calculated value of the maximum admissible speed of plasma-generating air that corresponds
to the critical regime of stable arcing in plasma spark plug at the GTE start. 相似文献
443.
A technique of evaluating the micromechanical characteristics (namely, microhardness, microdurability, microbrittleness and
static crack resistance coefficient) using microindentation as applied to plasma zirconia-based thermal barrier coatings is
presented. 相似文献
444.
The results of studying the characteristics of a two-phase flow being formed during adiabatic water efflux through axisymmetric
cylindrical and Laval nozzle channels are presented. Experiments were carried out with saturated water in the range of initial
pressures 0.6–4.0 MPa. The fluid efflux was performed into the air with atmospheric pressure. The generalizing relations for
calculating thrust pulse and critical flowrate were obtained. 相似文献
445.
A. L. Tukmakov V. G. Tonkonog A. G. Kochenkov S. A. Kusyumov 《Russian Aeronautics (Iz VUZ)》2011,54(4):402-411
A physical and mathematical model of a boiling-up fluid flow in the variable crosssection channels is proposed. The numerical
model is based on the solution of the Navier-Stokes nonstationary equations for compressible fluid by the implicit finite-difference
method. We present the results of the numerical modeling for two-phase flow characteristics at the initial stage of the evaporation
process and the steady-state quasistationary flow of a two-phase medium. 相似文献
446.
447.
V. A. Ivanov D. V. Ivanov N. V. Ryabova Luong Viet Loc E. V. Katkov 《Russian Aeronautics (Iz VUZ)》2017,60(2):286-291
The paper presents the methods and algorithms for positioning the dynamic (moving) objects using the oblique-incidence ionospheric sounding by chirp signals. Full-scale experiments have been performed to determine a distance to an object and its location. 相似文献
448.
449.
David Mimoun Naomi Murdoch Philippe Lognonné Kenneth Hurst William T. Pike Jane Hurley Tanguy Nébut William B. Banerdt SEIS Team 《Space Science Reviews》2017,211(1-4):383-428
The SEIS (Seismic Experiment for Interior Structures) instrument on board the InSight mission to Mars is the critical instrument for determining the interior structure of Mars, the current level of tectonic activity and the meteorite flux. Meeting the performance requirements of the SEIS instrument is vital to successfully achieve these mission objectives. The InSight noise model is a key tool for the InSight mission and SEIS instrument requirement setup. It will also be used for future operation planning. This paper presents the analyses made to build a model of the Martian seismic noise as measured by the SEIS seismometer, around the seismic bandwidth of the instrument (from 0.01 Hz to 1 Hz). It includes the instrument self-noise, but also the environment parameters that impact the measurements. We present the general approach for the model determination, the environment assumptions, and we analyze the major and minor contributors to the noise model. 相似文献
450.
A. V. Bykov G. V. Kondrashev S. G. Parafes’ I. K. Turkin 《Russian Aeronautics (Iz VUZ)》2016,59(3):331-337
Theoretical and experimental methods of investigating the performance of an electric actuator of maneuverable unmanned aerial vehicle (UAV) is considered in order to solve the aeroelasticity tasks. Models of the stability analysis for the rudder–actuator system as well as the examples of numerical and experimental studies of this system performance are given. 相似文献