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   6889篇
  免费   26篇
  国内免费   16篇
电工技术   69篇
综合类   15篇
化学工业   562篇
金属工艺   245篇
机械仪表   174篇
建筑科学   41篇
矿业工程   130篇
能源动力   82篇
轻工业   70篇
水利工程   67篇
石油天然气   180篇
武器工业   1篇
无线电   213篇
一般工业技术   661篇
冶金工业   3999篇
原子能技术   221篇
自动化技术   201篇
  2022年   38篇
  2021年   73篇
  2020年   51篇
  2019年   57篇
  2018年   90篇
  2017年   122篇
  2016年   121篇
  2015年   56篇
  2014年   92篇
  2013年   106篇
  2012年   111篇
  2011年   138篇
  2010年   128篇
  2009年   113篇
  2008年   112篇
  2007年   109篇
  2006年   81篇
  2005年   77篇
  2004年   58篇
  2003年   64篇
  2002年   63篇
  2001年   62篇
  2000年   55篇
  1999年   151篇
  1998年   1266篇
  1997年   754篇
  1996年   440篇
  1995年   278篇
  1994年   223篇
  1993年   236篇
  1992年   58篇
  1991年   43篇
  1990年   72篇
  1989年   64篇
  1988年   81篇
  1987年   63篇
  1986年   77篇
  1985年   63篇
  1983年   51篇
  1982年   44篇
  1981年   58篇
  1980年   62篇
  1979年   37篇
  1978年   51篇
  1977年   124篇
  1976年   198篇
  1975年   55篇
  1974年   46篇
  1973年   40篇
  1972年   37篇
排序方式: 共有6931条查询结果,搜索用时 0 毫秒
1.
Type testing for fault currents for medium-voltage circuit breakers rated at 15 kV to 72.5 kV is addressed. The ANSI designation of a new class of definite-purpose circuit breakers capable of switching transformer secondary faults and the introduction of the requirement for short-line-fault tests for breakers rated 72.5 kV and below have increased the difficulty of performing type tests in a testing laboratory. It is concluded that synthetic testing using the parallel current injection circuit is described in ANSI C37.081 provides the best available method for proving these complex requirements for medium-voltage circuit breakers  相似文献   
2.
Introduction of the BER? KOMPAKS® automated system at the Vyksa Metallurgical Plant to safely and efficiently manage the operation of the plant’s equipment has allowed the facility to begin operating that equipment based on real-time evaluations of its actual physical condition. Introduction of the new system has also allowed better coordination of repair-scheduling with ongoing production operations, significantly improved the reliability and readiness of the equipment for operation at 100% capacity, completely eliminated the human factor from the process of monitoring the condition of equipment, and made it possible to check the quality and timeliness of equipment maintenance and repair work so as to ensure safe, efficient operation of the entire production complex.  相似文献   
3.
4.
5.
Following the search for new design solutions to develop within the framework of channel trends the reactor with enhanced safety the Research and Development Institute of Power Engineering has developed the design of the multiloop boiling water reactor (MKER). The MKER enhanced safety is attained when involving the inherent safety features, passive safety systems as well as the accident consequences confinement devices. The design realizes several advantages which are typical of the channel-type reactors, namely: the design desintegration simplifying the manufacture, control, equipment delivery and decreasing, versus the pressure vessel reactors, the accident effect if it proceeds in an explosive manner; small operating reactivity margin and fuel burnup increased due to continuous refuelling; fuel cycle flexibility allowing comparatively easily to adopt the reactor to the conjuncture of the country fuel balance; multiloop circuit of the main coolant which reduces the degree and effect of the accidents connected with the equipment and pipings rupture; monitoring of the channels and fuel assemblies leak-tightness.  相似文献   
6.
Formulation of the problem of designing the optimal structure of an active system was considered within the framework of the game-theoretical model of interaction of its participants. Solution and the results of studying the control mechanisms in applications such as in-house management and multiagent systems were presented.  相似文献   
7.
8.
9.
Stability-optimal solutions were established for the problem of control of the aperiodic, delay, and oscillatory plants approximated by the dynamic models representing a serial connection of the inertial units, inertial delay unit, and inertial units with oscillatory unit.  相似文献   
10.
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