全文获取类型
收费全文 | 6440篇 |
免费 | 12篇 |
国内免费 | 11篇 |
专业分类
航空 | 2777篇 |
航天技术 | 2012篇 |
综合类 | 197篇 |
航天 | 1477篇 |
出版年
2021年 | 52篇 |
2019年 | 37篇 |
2018年 | 224篇 |
2017年 | 165篇 |
2016年 | 146篇 |
2015年 | 64篇 |
2014年 | 167篇 |
2013年 | 195篇 |
2012年 | 190篇 |
2011年 | 305篇 |
2010年 | 241篇 |
2009年 | 344篇 |
2008年 | 358篇 |
2007年 | 251篇 |
2006年 | 142篇 |
2005年 | 195篇 |
2004年 | 162篇 |
2003年 | 191篇 |
2002年 | 234篇 |
2001年 | 265篇 |
2000年 | 85篇 |
1999年 | 126篇 |
1998年 | 144篇 |
1997年 | 108篇 |
1996年 | 141篇 |
1995年 | 178篇 |
1994年 | 138篇 |
1993年 | 76篇 |
1992年 | 112篇 |
1991年 | 39篇 |
1990年 | 44篇 |
1989年 | 95篇 |
1988年 | 35篇 |
1987年 | 42篇 |
1986年 | 42篇 |
1985年 | 167篇 |
1984年 | 144篇 |
1983年 | 96篇 |
1982年 | 113篇 |
1981年 | 160篇 |
1980年 | 48篇 |
1979年 | 29篇 |
1978年 | 35篇 |
1977年 | 35篇 |
1976年 | 27篇 |
1975年 | 31篇 |
1974年 | 35篇 |
1972年 | 32篇 |
1971年 | 31篇 |
1969年 | 27篇 |
排序方式: 共有6463条查询结果,搜索用时 875 毫秒
621.
V. Génot C. Jacquey M. Bouchemit M. Gangloff A. Fedorov B. Lavraud N. André L. Broussillou C. Harvey E. Pallier E. Penou E. Budnik R. Hitier B. Cecconi F. Dériot D. Heulet J.-L. Pinçon 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
AMDA (Automated Multi-Dataset Analysis), a new data analysis service, recently opened at the French Plasma Physics Data Center (CDPP). AMDA is developed according to the Virtual Observatory paradigm: it is a web-based facility for on-line analyses of space physics. Data may come from its own local database as well as remote ones. This tool allows the user to perform classical manipulations such as data visualization, parameter computation and data extraction. AMDA also offers innovative functionalities such as event searches on the content of the data in either visual or automated ways, generation, use and management of time tables (event lists). The general functionalities of AMDA are presented in the context of Space Weather with example scientific use cases. 相似文献
622.
V. G. Gainutdinov 《Russian Aeronautics (Iz VUZ)》2010,53(3):277-282
An algorithm is proposed for computer-aided calculation of required values of aircraft controlling moments and aerodynamic
moment coefficients for stable fulfillment of flight trajectories specified by design flight performance. 相似文献
623.
A three-dimensional design model of a helicopter tubular skid landing gear based on the application of the large beam displacement
theory is presented. The design model takes into account special features of constructive, physical and geometrical deformation
nonlinearity. The analysis of a real helicopter structure is given that confirms sufficient validity of calculation results
obtained using the model developed by comparing with the results of the finite element analysis. 相似文献
624.
Yu. P. Kataev 《Russian Aeronautics (Iz VUZ)》2012,55(2):192-195
In this paper, a proper choice of technological parameters for a shot peening process is considered, namely, the shot diameter, shot blast velocity, density of shot material, and depth of a plastically deformed layer-depending on the material being processed. The data presented can be used in calculations of technological parameters of FV monolithic panel shaping. 相似文献
625.
C.J. Hailey T. Aramaki S.E. Boggs P.v. Doetinchem H. Fuke F. Gahbauer J.E. Koglin N. Madden S.A.I. Mognet R. Ong T. Yoshida T. Zhang J.A. Zweerink 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
The General Antiparticle Spectrometer (GAPS) is a new approach to the indirect detection of dark matter. It relies on searching for primary antideuterons produced in the annihilation of dark matter in the galactic halo. Low energy antideuterons produced through Standard Model processes, such as collisions of cosmic-rays with interstellar baryons, are greatly suppressed compared to primary antideuterons. Thus a low energy antideuteron search provides a clean signature of dark matter. In GAPS antiparticles are slowed down and captured in target atoms. The resultant exotic atom deexcites with the emission of X-rays and annihilation pions, protons and other particles. A tracking geometry allows for the detection of the X-rays and particles, providing a unique signature to identify the mass of the antiparticle. A prototype detector was successfully tested at the KEK accelerator in 2005, and a prototype GAPS balloon flight is scheduled for 2011. This will be followed by a full scale experiment on a long duration balloon from Antarctica in 2014. We discuss the status and future plans for GAPS. 相似文献
626.
C. P. T. Groth D. L. De Zeeuw T. I. Gombosi K. G. Powell 《Space Science Reviews》1999,87(1-2):193-198
A parallel adaptive mesh refinement (AMR) scheme is described for solving the governing equations of ideal magnetohydrodynamics
(MHD) in three space dimensions. This solution algorithm makes use of modern finite-volume numerical methodology to provide
a combination of high solution accuracy and computational robustness. Efficient and scalable implementations of the method
have been developed for massively parallel computer architectures and high performance achieved. Numerical results are discussed
for a simplified model of the initiation and evolution of coronal mass ejections (CMEs) in the inner heliosphere. The results
demonstrate the potential of this numerical tool for enhancing our understanding of coronal and solar wind plasma processes.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
627.
A regulated peak-power tracking (RPPT) system for space power application is proposed. Large-signal stability analysis is provided to understand the main four different modes of operations of the system, as well as the mode transitions. A simple and effective control scheme for the system is also proposed. Small-signal analysis is performed thereafter to provide design optimization, and the predictions are verified by computer simulations 相似文献
628.
The results of a preliminary analysis of microperturbations on the International Space Station during physical exercises of the crew are presented. The goal of this paper is to identify the parameters of perturbations
when physical exercises are performed. The results of measurements by sensors of microaccelerations of both Russian and American
segments during physical exercises in the service module of the Russian segment are analyzed. 相似文献
629.
A method is substantiated to ensure energy security for the satellite communication systems (SCS) at a close position of the
radio interception receiver. This is done by lowering the carrier frequency down to f
0 = 60…80 MHz and by applying spaced measurements with n ≥ 4 receiving antennas. 相似文献
630.
A. V. Tavrov O. I. Korablev A. V. Rodin I. I. Vinogradov A. Yu. Trokhimovsky A. Yu. Ivanov L. V. Ksanfomaliti D. A. Orlov 《Cosmic Research》2011,49(2):99-109
In order to observe exoplanets we propose a space-based achromatic stellar coronagraph combined with a 0.8–1.5 m telescope.
We develop an achromatic common path interferometer for observing an exoplanet (a faint off-axis source) on the background
of a hoste star (bright axial source). An image of the star and its copy acquire an achromatic phase shift by 180° and interfere
in antiphase. The achromatic phase shift is caused by geometric phase in the scheme of a three-dimensional interferometer.
The interference process divides spatially the dark and light fields of the star image redirecting them to the opposite sides
of a beam splitter. The interference process does not weaken the image of a planet, with equal intensities it is redirected
to both sides of a beam splitter. The suggested scheme of common path interferometer ensures mechanical stability. The background
signal is experimentally demonstrated to be reduced by six orders of magnitude. 相似文献