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   120313篇
  免费   9706篇
  国内免费   4699篇
电工技术   6903篇
技术理论   2篇
综合类   6067篇
化学工业   20047篇
金属工艺   6870篇
机械仪表   8206篇
建筑科学   6491篇
矿业工程   2247篇
能源动力   4323篇
轻工业   8611篇
水利工程   2151篇
石油天然气   3557篇
武器工业   1017篇
无线电   16124篇
一般工业技术   17511篇
冶金工业   7173篇
原子能技术   1546篇
自动化技术   15872篇
  2024年   314篇
  2023年   1401篇
  2022年   2679篇
  2021年   4135篇
  2020年   3041篇
  2019年   2696篇
  2018年   3133篇
  2017年   3526篇
  2016年   3756篇
  2015年   4201篇
  2014年   5822篇
  2013年   7294篇
  2012年   8762篇
  2011年   9611篇
  2010年   8358篇
  2009年   8233篇
  2008年   8018篇
  2007年   7106篇
  2006年   6569篇
  2005年   5453篇
  2004年   4461篇
  2003年   4179篇
  2002年   4164篇
  2001年   3602篇
  2000年   2497篇
  1999年   1982篇
  1998年   2122篇
  1997年   1502篇
  1996年   1216篇
  1995年   878篇
  1994年   703篇
  1993年   572篇
  1992年   406篇
  1991年   359篇
  1990年   343篇
  1989年   303篇
  1988年   240篇
  1987年   204篇
  1986年   147篇
  1985年   122篇
  1984年   100篇
  1983年   76篇
  1982年   48篇
  1981年   48篇
  1980年   38篇
  1979年   36篇
  1978年   32篇
  1977年   40篇
  1976年   63篇
  1975年   22篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
971.
This study determines a robust schedule for a flexible job-shop scheduling problem with flexible workdays. The performance criteria considered in this study are tardiness, overtime and robustness. Furthermore, the problem is addressed in a Pareto manner, and a set of Pareto-optimal solutions is determined for this purpose. In consideration of all the aforementioned features, a goal-guided neighbourhood function is proposed based on efficient problem-dependent move-filtering methods. Two metaheuristic algorithms, named goal-guided multi-objective tabu search and goal-guided multi-objective hybrid search, are proposed in this work based on this neighbourhood function. The effectiveness of these approaches is demonstrated via empirical studies.  相似文献   
972.
In many fields, there is the need to monitor quality characteristics defined as the ratio of two random variables. The design and implementation of control charts directly monitoring the ratio stability is required for the continuous surveillance of these quality characteristics. In this paper, we propose two one‐sided exponentially weighted moving average (EWMA) charts with subgroups having sample size n > 1 to monitor the ratio of two normal random variables. The optimal EWMA smoothing constants, control limits, and ARLs have been computed for different values of the in‐control ratio and correlation between the variables and are shown in several figures and tables to discuss the statistical performance of the proposed one‐sided EWMA charts. Both deterministic and random shift sizes have been considered to test the two one‐sided EWMA charts' sensitivity. The obtained results show that the proposed one‐sided EWMA control charts are more sensitive to process shifts than other charts already proposed in the literature. The practical application of the proposed control schemes is discussed with an illustrative example. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
973.
The electroencephalogram (EEG) is the frequently used signal to detect epileptic seizures in the brain. For a successful epilepsy surgery, it is very essential to localize epileptogenic area in the brain. The signals from the epileptogenic area are focal signals and signals from other area of the brain region nonfocal signals. Hence, the classification of focal and nonfocal signals is important for locating the epileptogenic area for epilepsy surgery. In this article, we present a computer aided automatic detection and classification method for focal and nonfocal EEG signal. The EEG signal is decomposed by Dual Tree Complex Wavelet Transform (DT‐CWT) and the features are computed from the decomposed coefficients. These features are trained and classified using Adaptive Neuro Fuzzy Inference System (ANFIS) classifier. The proposed system achieves 98% sensitivity, 100% specificity, and 99% accuracy for EEG signal classification. The experimental results are presented to show the effectiveness of the proposed classification method to classify the focal and nonfocal EEG signals. © 2016 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 26, 277–283, 2016  相似文献   
974.
975.
976.
977.
978.
979.
980.
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