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   100725篇
  免费   8167篇
  国内免费   4352篇
电工技术   5706篇
技术理论   6篇
综合类   6315篇
化学工业   16769篇
金属工艺   6204篇
机械仪表   7047篇
建筑科学   8217篇
矿业工程   3442篇
能源动力   2950篇
轻工业   6336篇
水利工程   1700篇
石油天然气   7421篇
武器工业   819篇
无线电   10843篇
一般工业技术   11700篇
冶金工业   4930篇
原子能技术   1040篇
自动化技术   11799篇
  2024年   458篇
  2023年   1805篇
  2022年   3190篇
  2021年   4362篇
  2020年   3387篇
  2019年   2740篇
  2018年   2952篇
  2017年   3323篇
  2016年   3079篇
  2015年   4159篇
  2014年   4971篇
  2013年   5910篇
  2012年   6386篇
  2011年   6818篇
  2010年   5842篇
  2009年   5578篇
  2008年   5434篇
  2007年   5134篇
  2006年   5461篇
  2005年   4756篇
  2004年   3024篇
  2003年   2860篇
  2002年   2689篇
  2001年   2430篇
  2000年   2356篇
  1999年   2665篇
  1998年   2110篇
  1997年   1744篇
  1996年   1722篇
  1995年   1428篇
  1994年   1174篇
  1993年   746篇
  1992年   653篇
  1991年   445篇
  1990年   354篇
  1989年   307篇
  1988年   232篇
  1987年   151篇
  1986年   122篇
  1985年   70篇
  1984年   54篇
  1983年   45篇
  1982年   41篇
  1981年   28篇
  1980年   26篇
  1979年   16篇
  1978年   1篇
  1965年   1篇
  1959年   4篇
  1951年   1篇
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
141.
142.
This paper addresses the stability issue of discrete-time switched systems with guaranteed dwell-time. The approach of switched homogeneous Lyapunov function of higher order is formally proposed. By means of this approach, a necessary and sufficient condition is established to check the exponential stability of the considered system. With the observation that switching signal is actually arbitrary if the dwell time is one sample time, a necessary and sufficient condition is also presented to verify the exponential stability of switched systems under arbitrary switching signals. Using the augmented argument, a necessary and sufficient exponential stability criterion is given for discrete-time switched systems with delays. A numerical example is provided to show the advantages of the theoretical results.  相似文献   
143.
144.
145.
Person re-identification receives increasing attentions in computer vision due to its potential applications in video surveillance. In order to alleviate wrong matches caused by misalignment or missing features among cameras, we propose to learn a multi-view gallery of frequently appearing objects in a relatively closed environment. The gallery contains appearance models of these objects from different cameras and viewpoints. The strength of the learned appearance models lies in that they are invariant to viewpoint and illumination changes. To automatically estimate the number of frequently appearing objects in the environment and update their appearance models online, we propose a dynamic gallery learning algorithm. We specifically build up two datasets to validate the effectiveness of our approach in realistic scenarios. Comparisons with benchmark methods demonstrate promising performance in accuracy and efficiency of re-identification.  相似文献   
146.
Lu  Zhao  Lin  Yu-Ru  Huang  Xiaoxia  Xiong  Naixue  Fang  Zhijun 《Multimedia Tools and Applications》2017,76(8):10855-10879
Multimedia Tools and Applications - Nowadays, microblogging has become popular, with hundreds of millions of short messages being posted and shared every minute on a variety of topics in social...  相似文献   
147.
Deng  Juan  Zhao  Shu  Wang  Yan  Wang  Lei  Wang  Hong  Sha  Hong 《Multimedia Tools and Applications》2017,76(7):10097-10117
Multimedia Tools and Applications - Most of the existing image encryption algorithms based on compressive sensing are too complex to operate. An image compression-encryption scheme with simple...  相似文献   
148.
In this paper, we address two important issues in the video concept detection problem: the insufficiency of labeled videos and the multiple labeling issue. Most existing solutions merely handle the two issues separately. We propose an integrated approach to handle them together, by presenting an effective transductive multi-label classification approach that simultaneously models the labeling consistency between the visually similar videos and the multi-label interdependence for each video. We compare the performance between the proposed approach and several representative transductive and supervised multi-label classification approaches for the video concept detection task over the widely used TRECVID data set. The comparative results demonstrate the superiority of the proposed approach.  相似文献   
149.
In a graph theory model, clustering is the process of division of vertices into groups, with a higher density of edges within groups than between them. In this paper, we introduce a new clustering method for detecting such groups and use it to analyse some classic social networks. The new method has two distinguished features: non-binary hierarchical tree and the feature of overlapping clustering. A non-binary hierarchical tree is much smaller than the binary-trees constructed by most traditional methods and, therefore, it clearly highlights meaningful clusters which significantly reduces further manual efforts for cluster selections. The present method is tested by several bench mark data sets for which the community structure was known beforehand and the results indicate that it is a sensitive and accurate method for extracting community structure from social networks.  相似文献   
150.
OMT在企业物流分析中的应用   总被引:2,自引:1,他引:1  
文章介绍了面向对象的模型化技术(OMT)的基本概念,分析了它的实现过程,即对象模型、动态模型、和过程模型的建立,并以一个具体的实例说明其在企业物流分析中的应用。  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