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   600804篇
  免费   7937篇
  国内免费   1164篇
电工技术   10997篇
综合类   1091篇
化学工业   93558篇
金属工艺   23845篇
机械仪表   19314篇
建筑科学   13342篇
矿业工程   4692篇
能源动力   14816篇
轻工业   47410篇
水利工程   7421篇
石油天然气   15007篇
武器工业   43篇
无线电   61865篇
一般工业技术   119137篇
冶金工业   111828篇
原子能技术   14830篇
自动化技术   50709篇
  2021年   5562篇
  2019年   5315篇
  2018年   9637篇
  2017年   10038篇
  2016年   10815篇
  2015年   6756篇
  2014年   10635篇
  2013年   26497篇
  2012年   17649篇
  2011年   23271篇
  2010年   17581篇
  2009年   19510篇
  2008年   19591篇
  2007年   19301篇
  2006年   16796篇
  2005年   17743篇
  2004年   16366篇
  2003年   15585篇
  2002年   14036篇
  2001年   13551篇
  2000年   12598篇
  1999年   12484篇
  1998年   32064篇
  1997年   22791篇
  1996年   17457篇
  1995年   13102篇
  1994年   11648篇
  1993年   11455篇
  1992年   8513篇
  1991年   8319篇
  1990年   8204篇
  1989年   7969篇
  1988年   7692篇
  1987年   6916篇
  1986年   6671篇
  1985年   7524篇
  1984年   6760篇
  1983年   6496篇
  1982年   5892篇
  1981年   6048篇
  1980年   5791篇
  1979年   5789篇
  1978年   5748篇
  1977年   6727篇
  1976年   8833篇
  1975年   5198篇
  1974年   4936篇
  1973年   5017篇
  1972年   4313篇
  1971年   4075篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
991.
992.
993.
The basic characteristics of the multi-effect boiling (MEB) desalination system are presented. Recent developments are considered, and a thermodynamic analysis and evaluation of the heat transfer areas required for the MEB system are given. In comparing the heat transfer areas, water pretreatment and salt concentration, pumping power requirement and stability of the MEB and multi-stage flash (MSF) systems, MEB seems to have definite advantages over MSF. However, in the absence of well-proven large capacity MEB units, and in view of the good experience with and reliability of MSF systems, large producers of desalted water favor continued installation of MSF systems.  相似文献   
994.
995.
996.
Computing must become much more human centered--for example, by presenting personalized information to users and by respecting personal preferences when controlling multiple devices or invoking various services. Appropriate representation of the information's semantics and of the functionality of devices and services will be critical to such personalized computing. Symbolic artificial intelligence techniques provide the method of choice for the required semantic-representation and reasoning capabilities.  相似文献   
997.
/sup T/he University of Minnesota's Scout is a small cylindrical robot capable of rolling and jumping. Models describing the robot's motion are developed. These models can be employed for motion prediction and simulation. The results suggest that the determining factor of the Scout's behavior is the length of the winch cable.  相似文献   
998.
The authors argued that AI systems must be able to manipulate their own internal representations automatically to deal with an infinitely complex and ever-changing world and to scale up to rich, complex applications. Such manipulation must go beyond changing beliefs and learning new concepts in terms of old concepts; it must be able to change ontology's underlying syntax and semantics. Initial progress has been made, but further progress is urgently needed owing to the demands of autonomous multiagent systems. Understanding and implementing this ability must be a major focus of AI for the next 50 years.  相似文献   
999.
Design and implementation of a sequential controller based on the concept of artificial neural networks for a flexible manufacturing system are presented. The recurrent neural network (RNN) type is used for such a purpose. Contrary to the programmable controller, an RNN-based sequential controller is based on a definite mathematical model rather than depending on experience and trial and error techniques. The proposed controller is also more flexible because it is not limited by the restrictions of the finite state automata theory. Adequate guidelines of how to construct an RNN-based sequential controller are presented. These guidelines are applied to different case studies. The proposed controller is tested by simulations and real-time experiments. These tests prove the successfulness of the proposed controller performances. Theoretical as well as experimental results are presented and discussed indicating that the proposed design procedure using Elman's RNN can be effective in designing a sequential controller for event-based type manufacturing systems. In addition, the simulation results assure the effectiveness of the proposed controller to outperform the effect of noisy inputs.  相似文献   
1000.
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