首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4217篇
  免费   6篇
  国内免费   12篇
航空   2293篇
航天技术   1082篇
综合类   9篇
航天   851篇
  2018年   172篇
  2017年   143篇
  2016年   58篇
  2015年   37篇
  2014年   55篇
  2013年   78篇
  2012年   100篇
  2011年   236篇
  2010年   208篇
  2009年   242篇
  2008年   266篇
  2007年   230篇
  2006年   63篇
  2005年   133篇
  2004年   93篇
  2003年   105篇
  2002年   53篇
  2001年   102篇
  2000年   49篇
  1999年   79篇
  1998年   93篇
  1997年   73篇
  1996年   91篇
  1995年   124篇
  1994年   98篇
  1993年   69篇
  1992年   102篇
  1991年   42篇
  1990年   36篇
  1989年   87篇
  1988年   32篇
  1987年   28篇
  1986年   32篇
  1985年   87篇
  1984年   91篇
  1983年   59篇
  1982年   83篇
  1981年   92篇
  1980年   34篇
  1979年   42篇
  1978年   32篇
  1977年   22篇
  1976年   21篇
  1975年   37篇
  1974年   24篇
  1973年   18篇
  1972年   29篇
  1969年   17篇
  1967年   20篇
  1966年   16篇
排序方式: 共有4235条查询结果,搜索用时 187 毫秒
201.
The DB-8 detectors of the ISS radiation monitoring system (RMS) have operated almost continuously onboard the ISS service module since August 2001 till December 2014. The RMS data obtained were used for the daily monitoring of the radiation environment aboard the station. This paper considers the technique of RMS data analysis that allows one to distinguish the contributions of galactic cosmic rays and the Earth’s inner radiation belt to the daily dose based on the dosimetry data obtained as a result of the station’s passage in areas of the highest geomagnetic latitudes. The paper presents the results of an analysis of the dosimetry data based on this technique for 2005–2011, as well as a comparison with similar results the authors obtained previously using the technique based on an analysis of the dosimetry data obtained during station passages in the area of the South Atlantic Anomaly.  相似文献   
202.
203.
204.
205.
A method of determining the maximum permissible values for diagnostic signs, being an integral part of health and usage monitoring systems (HUMS) of the helicopter transmission units, has been developed based on a probabilistic approach.  相似文献   
206.
Based on an integrated approach, we solve the optimization problem for energy content and weight-dimensional characteristics of the electric servo drive by synthesis of structure and analysis of characteristics for different power supplies. The generalized power supply model, developed for different power supply of drive control systems, is given.  相似文献   
207.
The problem and features of measuring the speed and the direction angle of the wind vector relative to the longitudinal helicopter axis during parking, starting and takeoff-landing modes by onboard means are considered. The construction principles, information processing algorithms and advantages of onboard system for measuring the wind vector parameters based on ion-beacon and aerometric measuring channels, are disclosed.  相似文献   
208.
209.
A methodology of creating a loading imitation model of a single-rotor helicopter with artificial neural network algorithms is considered. Stages of creation, the structure, and an algorithm of searching for an optimal neural networks configuration of loading imitation model are presented.  相似文献   
210.
A weak but statistically reliable dependence of the diurnal activity of oscillations in the ionospheric Alfvén resonator on orientation of the interplanetary magnetic field ahead of the magnetospheric front has been detected based on observations of ULF oscillations at Sayan solar observatory Mondy of the Institute of Solar–Terrestrial Physics. The interpretation of the result has been proposed. The essence is that the electromagnetic fluctuations penetrate into the magnetosphere from the interplanetary environment and influence the ionospheric resonator. The formulation of the problem and the method of solving it are part of the broad program of the experimental and theoretical study of the influence of the interplanetary magnetic field on the oscillation regime of ULF oscillations of the magnetosphere.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号