全文获取类型
收费全文 | 419篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
航空 | 277篇 |
航天技术 | 51篇 |
综合类 | 1篇 |
航天 | 94篇 |
出版年
2021年 | 5篇 |
2019年 | 3篇 |
2018年 | 69篇 |
2017年 | 37篇 |
2016年 | 3篇 |
2015年 | 5篇 |
2014年 | 4篇 |
2013年 | 15篇 |
2012年 | 12篇 |
2011年 | 37篇 |
2010年 | 12篇 |
2009年 | 15篇 |
2008年 | 20篇 |
2007年 | 22篇 |
2006年 | 10篇 |
2005年 | 17篇 |
2004年 | 11篇 |
2003年 | 15篇 |
2002年 | 3篇 |
2001年 | 7篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1968年 | 3篇 |
1967年 | 9篇 |
1966年 | 11篇 |
排序方式: 共有423条查询结果,搜索用时 46 毫秒
182.
InSight Mars Lander Robotics Instrument Deployment System 总被引:1,自引:0,他引:1
A. Trebi-Ollennu Won Kim Khaled Ali Omair Khan Cristina Sorice Philip Bailey Jeffrey Umland Robert Bonitz Constance Ciarleglio Jennifer Knight Nicolas Haddad Kerry Klein Scott Nowak Daniel Klein Nicholas Onufer Kenneth Glazebrook Brad Kobeissi Enrique Baez Felix Sarkissian Menooa Badalian Hallie Abarca Robert G. Deen Jeng Yen Steven Myint Justin Maki Ali Pourangi Jonathan Grinblat Brian Bone Noah Warner Jaime Singer Joan Ervin Justin Lin 《Space Science Reviews》2018,214(5):93
The InSight Mars Lander is equipped with an Instrument Deployment System (IDS) and science payload with accompanying auxiliary peripherals mounted on the Lander. The InSight science payload includes a seismometer (SEIS) and Wind and Thermal Shield (WTS), heat flow probe (Heat Flow and Physical Properties Package, HP3) and a precision tracking system (RISE) to measure the size and state of the core, mantle and crust of Mars. The InSight flight system is a close copy of the Mars Phoenix Lander and comprises a Lander, cruise stage, heatshield and backshell. The IDS comprises an Instrument Deployment Arm (IDA), scoop, five finger “claw” grapple, motor controller, arm-mounted Instrument Deployment Camera (IDC), lander-mounted Instrument Context Camera (ICC), and control software. IDS is responsible for the first precision robotic instrument placement and release of SEIS and HP3 on a planetary surface that will enable scientists to perform the first comprehensive surface-based geophysical investigation of Mars’ interior structure. This paper describes the design and operations of the Instrument Deployment Systems (IDS), a critical subsystem of the InSight Mars Lander necessary to achieve the primary scientific goals of the mission including robotic arm geology and physical properties (soil mechanics) investigations at the Landing site. In addition, we present test results of flight IDS Verification and Validation activities including thermal characterization and InSight 2017 Assembly, Test, and Launch Operations (ATLO), Deployment Scenario Test at Lockheed Martin, Denver, where all the flight payloads were successfully deployed with a balloon gravity offload fixture to compensate for Mars to Earth gravity. 相似文献
183.
Jill Tarter Robert Ackermann William Barott Peter Backus Michael Davis John Dreher Gerald Harp Jane Jordan Tom Kilsdonk Seth Shostak Ken Smolek 《Acta Astronautica》2011,68(3-4):340-346
The Search for ExtraTerrestrial Intelligence (SETI) finally has its own full-time telescope. The Allen telescope array (ATA) in Northern California was dedicated on October 11, 2007. This array, which will eventually be composed of 350 small radio antennas, each 6.1 m in diameter, is being built as a partnership between the SETI Institute and the University of California Radio Astronomy Laboratory. Last October, Paul G. Allen (who provided the funds for the technology development and the first phase of array construction) pushed a silver button and all 42 antennas of the current ATA-42 slewed to point in the direction of the distant galaxy M81. Specialized electronic backend detectors attached to the ATA began making a radio map of that galaxy and simultaneously began SETI observations of HIP48573, a G5V star near M81 on the sky and a distance of 264 light years from Earth. The Allen telescope array will greatly improve the speed of conducting SETI searches over the next few decades, and it will allow a suite of different search strategies to be undertaken. This paper summarizes some of the earliest SETI observations from the array, and describes the search strategies currently being planned. 相似文献
184.
First Results of the THEMIS Search Coil Magnetometers 总被引:1,自引:0,他引:1
O. Le Contel A. Roux P. Robert C. Coillot A. Bouabdellah B. de la Porte D. Alison S. Ruocco V. Angelopoulos K. Bromund C. C. Chaston C. Cully H. U. Auster K. H. Glassmeier W. Baumjohann C. W. Carlson J. P. McFadden D. Larson 《Space Science Reviews》2008,141(1-4):509-534
We present the first data from the THEMIS Search Coil Magnetometers (SCM), taken between March and June 2007 while the THEMIS constellation apogee moved from the duskside toward the dawnside. Data reduction, especially the SCM calibration method and spurious noise reduction process, is described. The signatures of magnetic fluctuations in key magnetospheric regions such as the bow shock, the magnetopause and the magnetotail during a substorm, are described. We also discuss the role that magnetic fluctuations could play in plasma transport, acceleration and heating. 相似文献
185.
Aubrey AD Chalmers JH Bada JL Grunthaner FJ Amashukeli X Willis P Skelley AM Mathies RA Quinn RC Zent AP Ehrenfreund P Amundson R Glavin DP Botta O Barron L Blaney DL Clark BC Coleman M Hofmann BA Josset JL Rettberg P Ride S Robert F Sephton MA Yen A 《Astrobiology》2008,8(3):583-595
The Urey organic and oxidant detector consists of a suite of instruments designed to search for several classes of organic molecules in the martian regolith and ascertain whether these compounds were produced by biotic or abiotic processes using chirality measurements. These experiments will also determine the chemical stability of organic molecules within the host regolith based on the presence and chemical reactivity of surface and atmospheric oxidants. Urey has been selected for the Pasteur payload on the European Space Agency's (ESA's) upcoming 2013 ExoMars rover mission. The diverse and effective capabilities of Urey make it an integral part of the payload and will help to achieve a large portion of the mission's primary scientific objective: "to search for signs of past and present life on Mars." This instrument is named in honor of Harold Urey for his seminal contributions to the fields of cosmochemistry and the origin of life. 相似文献
186.
Frank Sohl Mathieu Choukroun Jeffrey Kargel Jun Kimura Robert Pappalardo Steve Vance Mikhail Zolotov 《Space Science Reviews》2010,153(1-4):485-510
The state of knowledge about the structure and composition of icy satellite interiors has been significantly extended by combining direct measurements from spacecraft, laboratory experiments, and theoretical modeling. The existence of potentially habitable liquid water reservoirs on icy satellites is dependent on the radiogenic heating of the rock component, additional contributions such as the dissipation of tidal energy, the efficiency of heat transfer to the surface, and the presence of substances that deplete the freezing point of liquid water. This review summarizes the chemical evolution of subsurface liquid water oceans, taking into account a number of chemical processes occuring in aqueous environments and partly related to material exchange with the deep interior. Of interest are processes occuring at the transitions from the liquid water layer to the ice layers above and below, involving the possible formation of clathrate hydrates and high-pressure ices on large icy satellites. In contrast, water-rock exchange is important for the chemical evolution of the liquid water layer if the latter is in contact with ocean floor rock on small satellites. The composition of oceanic floor deposits depends on ambient physical conditions and ocean chemistry, and their evolutions through time. In turn, physical properties of the ocean floor affect the circulation of oceanic water and related thermal effects due to tidally-induced porous flow and aqueous alteration of ocean floor rock. 相似文献
187.
Farzad Kamalabadi Jianqi Qin Brian J. Harding Dimitrios Iliou Jonathan J. Makela R. R. Meier Scott L. England Harald U. Frey Stephen B. Mende Thomas J. Immel 《Space Science Reviews》2018,214(4):70
The Ionospheric Connection Explorer (ICON) Far Ultraviolet (FUV) imager, ICON FUV, will measure altitude profiles of OI 135.6 nm emissions to infer nighttime ionospheric parameters. Accurate estimation of the ionospheric state requires the development of a comprehensive radiative transfer model from first principles to quantify the effects of physical processes on the production and transport of the 135.6 nm photons in the ionosphere including the mutual neutralization contribution as well as the effect of resonant scattering by atomic oxygen and pure absorption by oxygen molecules. This forward model is then used in conjunction with a constrained optimization algorithm to invert the anticipated ICON FUV line-of-sight integrated measurements. In this paper, we describe the connection between ICON FUV measurements and the nighttime ionosphere, along with the approach to inverting the measured emission profiles to derive the associated O+ profiles from 150–450 km in the nighttime ionosphere that directly reflect the electron density in the F-region of the ionosphere. 相似文献
188.
美国空军和海军正联合开发适用于各军兵种的供应链和零部件跟踪系统.新系统的应用可以提高供应链效率、节省成本并为军民合作带来好处. 相似文献
189.
There have been many significant advances in understanding magnetic field reconnection as a result of improved space measurements
and two-dimensional computer simulations. While reviews of recent work have tended to focus on symmetric reconnection on ion
and larger spatial scales, the present review will focus on asymmetric reconnection and on electron scale physics involving
the reconnection site, parallel electric fields, and electron acceleration. 相似文献
190.
The information on the project being developed in Brazil for a flight to binary or triple near-Earth asteroid is presented.
The project plans to launch a spacecraft into an orbit around the asteroid and to study the asteroid and its satellite within
six months. Main attention is concentrated on the analysis of trajectories of flight to asteroids with both impulsive and
low thrust in the period 2013-2020. For comparison, the characteristics of flights to the (45) Eugenia triple asteroid of
the Main Belt are also given. 相似文献