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Lohr D. A. Zanetti L. J. Anderson B. J. Potemra T. A. Hayes J. R. Gold R. E. Henshaw R. M. Mobley F. F. Holland D. B. Acuña M. H. Scheifele J. L. 《Space Science Reviews》1997,82(1-2):255-281
The primary objective of the investigation is the search for a body-wide magnetic field of the near Earth asteroid Eros. The Near Earth Asteroid Rendezvous (NEAR) 3-axis fluxgate magnetometer includes a sensor mounted on the high-gain antenna feed structure. The NEAR Magnetic Facility Instrument (MFI) is a joint hardware effort between GSFC and APL. The design and magnetics approach achieved by the NEAR MFI effort entailed low-cost, up-front attention to engineering solutions which did not impact the schedule. The goal of the magnetometer is reliable magnetic field measurements within 5 nT, which necessitates the use of an extensive spacecraft magnetic interference model but is achievable with the full year's orbital data set. Such a goal has been shown viable with recent in-flight calibration data and comparisons to the WIND magnetometer data. The NEAR MFI effort has succeeded in providing magnetic field measurements for the first flight in NASA's Discovery line. 相似文献
685.
The ACE Magnetic Fields Experiment 总被引:2,自引:0,他引:2
Smith C.W. L'Heureux J. Ness N.F. Acuña M.H. Burlaga L.F. Scheifele J. 《Space Science Reviews》1998,86(1-4):613-632
The magnetic field experiment on ACE provides continuous measurements of the local magnetic field in the interplanetary medium.
These measurements are essential in the interpretation of simultaneous ACE observations of energetic and thermal particles
distributions. The experiment consists of a pair of twin, boom- mounted, triaxial fluxgate sensors which are located 165 inches
(=4.19 m) from the center of the spacecraft on opposing solar panels. The electronics and digital processing unit (DPU) is
mounted on the top deck of the spacecraft. The two triaxial sensors provide a balanced, fully redundant vector instrument
and permit some enhanced assessment of the spacecraft's magnetic field. The instrument provides data for Browse and high-level
products with between 3 and 6 vector s−1 resolution for continuous coverage of the interplanetary magnetic field. Two high-resolution
snapshot buffers each hold 297 s of 24 vector s−1 data while on- board Fast Fourier Transforms extend the continuous data
to 12 Hz resolution. Real-time observations with 1-s resolution are provided continuously to the Space Environmental Center
(SEC) of the National Oceanographic and Atmospheric Association (NOAA) for near- instantaneous, world-wide dissemination in
service to space weather studies. As has been our team's tradition, high instrument reliability is obtained by the use of
fully redundant systems and extremely conservative designs. We plan studies of the interplanetary medium in support of the
fundamental goals of the ACE mission and cooperative studies with other ACE investigators using the combined ACE dataset as
well as other ISTP spacecraft involved in the general program of Sun-Earth Connections.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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N.U. Crooker J.T. Gosling V. Bothmer R.J. Forsyth P.R. Gazis A. Hewish T.S. Horbury D.S. Intriligator J.R. Jokipii J. Kóta A.J. Lazarus M.A. Lee E. Lucek E. Marsch A. Posner I.G. Richardson E.C. Roelof J.M. Schmidt G.L. Siscoe B.T. Tsurutani R.F. Wimmer-Schweingruber 《Space Science Reviews》1999,89(1-2):179-220
Corotating interaction regions (CIRs) in the middle heliosphere have distinct morphological features and associated patterns
of turbulence and energetic particles. This report summarizes current understanding of those features and patterns, discusses
how they can vary from case to case and with distance from the Sun and possible causes of those variations, presents an analytical
model of the morphological features found in earlier qualitative models and numerical simulations, and identifies aspects
of the features and patterns that have yet to be resolved.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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月球表面的辐射剂量是影响航天员安全和月表驻留时间的重要参数,通过对月表的粒子辐射测量可以为航天员的辐射安全防护提供重要依据.利用嫦娥四号着陆器上搭载的月表中子与辐射剂量探测仪二年的观测数据得到:月表粒子辐射在硅中的平均总吸收剂量率为12.66±0.45μGy·h-1,中性粒子吸收剂量率为2.67±0.16μGy·h-1.辐射剂量率随时间出现缓慢的下降,LET谱的变化则很小.同时观测到了2020年12月太阳活动末期由于银河宇宙线福布斯下降导致的辐射剂量率降低. 相似文献
690.
C.Q. Xiang F.S. Wei X.S. Feng J.F. Wang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2005,36(12):2308-2312
The evolution of coronal mass ejection/shock system is investigated by numerically solving the usual set of two-dimensional single-fluid polytropic magnetohydrodynamic equations from 1 Rs to 1 AU in the meridian plane. The simulation result reveals that the coronal mass ejection/shock system formed near the sun evolves into the magnetic cloud/shock system near the earth’s orbit through the following three phases: the initial formation, the dominant latitudinal expansion and the similar expansion. 相似文献