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   202981篇
  免费   2397篇
  国内免费   629篇
电工技术   3528篇
综合类   152篇
化学工业   29637篇
金属工艺   8207篇
机械仪表   6145篇
建筑科学   4973篇
矿业工程   1312篇
能源动力   5250篇
轻工业   17364篇
水利工程   2324篇
石油天然气   4112篇
武器工业   9篇
无线电   23349篇
一般工业技术   40847篇
冶金工业   37503篇
原子能技术   5147篇
自动化技术   16148篇
  2021年   1677篇
  2019年   1627篇
  2018年   2668篇
  2017年   2740篇
  2016年   2882篇
  2015年   1853篇
  2014年   3156篇
  2013年   9104篇
  2012年   5198篇
  2011年   7210篇
  2010年   5742篇
  2009年   6494篇
  2008年   6552篇
  2007年   6630篇
  2006年   5691篇
  2005年   5306篇
  2004年   5075篇
  2003年   4980篇
  2002年   4617篇
  2001年   4746篇
  2000年   4637篇
  1999年   4779篇
  1998年   11469篇
  1997年   8203篇
  1996年   6473篇
  1995年   4726篇
  1994年   4328篇
  1993年   4132篇
  1992年   3263篇
  1991年   3117篇
  1990年   2903篇
  1989年   2984篇
  1988年   2865篇
  1987年   2441篇
  1986年   2357篇
  1985年   2747篇
  1984年   2539篇
  1983年   2358篇
  1982年   2108篇
  1981年   2227篇
  1980年   2044篇
  1979年   2145篇
  1978年   2133篇
  1977年   2385篇
  1976年   3219篇
  1975年   1847篇
  1974年   1775篇
  1973年   1788篇
  1972年   1453篇
  1971年   1352篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
This paper presents results of reliability investigation of 20 V N-Drift MOS transistor in 0.13 μm CMOS technology. Due to high performances required for CMOS applications, adding high voltage devices becomes a big challenge to guarantee the reliability criteria. In this context, new reliability approaches are needed. Safe Operating Area are defined for switch, Vds limited and Vgs limited applications in order to improve circuit designs. For Vds limited applications, deep doping dose effects in drift area are investigated in correlation to lifetime evaluations based on device parameter shifts under hot carrier stressing. To further determine the amount and locations of hot carriers injections, accurate 2D technological and electrical simulations are performed and permit to select the best compromise between performance and reliability for N-Drift MOS transistor.  相似文献   
83.
84.
This paper is devoted to presenting controllability and stabilizability issues associated to a class of nonsmooth dynamical systems, namely complementarity dynamical systems. The main existing results are summarized, and some possible research directions are provided. Convex analysis and complementarity problems are claimed to be the main analysis tools for control related studies. This paper mainly focuses on mechanical applications.  相似文献   
85.
The Metaflow architecture, a unified approach to maximizing the performance of superscalar microprocessors, is introduced. The Metaflow architecture exploits inherent instruction-level parallelism in conventional sequential programs by hardware means, without relying on optimizing compilers. It is based on a unified structure, the DRIS (deferred-scheduling, register-renaming instruction shelf), that manages out-of-order execution and most of the attendant problems. Coupling the DRIS with a speculative-execution mechanism that avoids conditional branch stalls results in performance limited only be inherent instruction-level parallelism and available execution resources. Although presented in the context of superscalar machines, the technique is equally applicable to a superpipelined implementation. Lightning, the first implementation of the Metaflow architecture, which executes the Sparc RISC instruction set is described  相似文献   
86.
87.
88.
89.
90.
Neural networks and blood cell identification   总被引:1,自引:0,他引:1  
The objective of this project is to propose a method of identifying cells found in human blood and to classify them based upon their morphological features using neural networks. The project focuses on three major blood cell types, namely, erythrocytes, leukocytes and platelets. The data are collected using peripheral blood smears from clinical patients. The image acquisition requires 100x magnification on all the blood smears, the preprocessing involves the use of median and edge enhance filters; the feature extraction is done by performing the wavelet transform on the images. Finally classification of the blood cell types is done using ALOPEX and Back Propagation trained neural networks. The efficacy of both networks is then compared by comparing their outputs and number of iterations required to reach the final result.  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