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   9715篇
  免费   94篇
  国内免费   53篇
电工技术   232篇
综合类   52篇
化学工业   267篇
金属工艺   312篇
机械仪表   149篇
建筑科学   61篇
矿业工程   15篇
能源动力   45篇
轻工业   25篇
水利工程   14篇
石油天然气   37篇
武器工业   11篇
无线电   368篇
一般工业技术   136篇
冶金工业   57篇
原子能技术   118篇
自动化技术   7963篇
  2024年   7篇
  2023年   3篇
  2022年   23篇
  2021年   18篇
  2020年   26篇
  2019年   24篇
  2018年   30篇
  2017年   29篇
  2016年   27篇
  2015年   40篇
  2014年   245篇
  2013年   214篇
  2012年   810篇
  2011年   2313篇
  2010年   1135篇
  2009年   975篇
  2008年   691篇
  2007年   595篇
  2006年   479篇
  2005年   614篇
  2004年   527篇
  2003年   590篇
  2002年   288篇
  2001年   14篇
  2000年   17篇
  1999年   29篇
  1998年   20篇
  1997年   25篇
  1996年   10篇
  1995年   12篇
  1994年   11篇
  1993年   6篇
  1992年   6篇
  1991年   1篇
  1990年   1篇
  1989年   2篇
  1988年   3篇
  1987年   1篇
  1981年   1篇
排序方式: 共有9862条查询结果,搜索用时 15 毫秒
1.
The patterning of contact holes by selecting out-of-focus image plane (defocus) using attenuated phase shift masks (APSM) has been studied. Defocus is found to enhance the image modulation at low partial coherence for contact holes with negative local average of mask function. Semi-dense holes up to 130 nm in 8% APSM have been printed by 0.5 μm defocus at a partial coherence of 0.31 using KrF scanner with highest numerical aperture of 0.68. However, these holes were closed with in-focus imaging. Defocus is also found to be beneficial for patterning the pitches that have extensive side lobes with in-focus imaging.  相似文献   
2.
A stochastic realization problem of a stationary stochastic process is re-visited, and a new stochastically balanced realization algorithm is derived in a Hilbert space generated by second-order stationary processes. The present algorithm computes a stochastically balanced realization by means of the singular value decomposition of a weighted block Hankel matrix derived by a “block LQ decomposition”. Extension to a stochastic subspace identification method explains how the proposed abstract algorithm is implemented in system identification.  相似文献   
3.
4.
This paper presents a system that can perform pedestrian detection and tracking using vision-based techniques. A very important issue in the field of intelligent transportation system is to prevent pedestrians from being hit by vehicles. Recently, a great number of vision-based techniques have been proposed for this purpose. In this paper, we propose a vision-based method, which combines the use of a pedestrian model as well as the walking rhythm of pedestrians to detect and track walking pedestrians. Through integrating some spatial and temporal information grabbed by a vision system, we are able to develop a reliable system that can be used to prevent traffic accidents happened at crossroads. In addition, the proposed system can deal with the occlusion problem. Experimental results obtained by executing some real world cases have demonstrated that the proposed system is indeed superb.  相似文献   
5.
In this article, we present a parallel image processing system based on the concept of reactive agents. Our system lies in the oRis language, which allows to describe finely and simply the agents’ behaviors to detect image features. We also present a method of segmentation using a multi-agent system, and two biological applications made with oRis. The stopping of this multi-agent system is implemented through a technique issued from immunology: the apoptosis.  相似文献   
6.
7.
This paper proposes a frequency domain algorithm for Wiener model identifications based on exploring the fundamental frequency and harmonics generated by the unknown nonlinearity. The convergence of the algorithm is established in the presence of white noise. No a priori knowledge of the structure of the nonlinearity is required and the linear part can be nonparametric.  相似文献   
8.
This paper generalizes the frequency-domain results on the delay-type Nehari problem in the stable case to the unstable case. The solvability condition of the delay-type Nehari problem is formulated in terms of the nonsingularity of three matrices. The optimal value γopt is the maximal γ∈(0,∞) such that one of the three matrices becomes singular. All sub-optimal compensators are parameterized in a transparent structure incorporating a modified Smith predictor.  相似文献   
9.
本文详细叙述了海上靶场角度量录取糸统的组成、测试原理及其功能设计,简要介绍了该系统在靶扬的应用情况.  相似文献   
10.
The selection of valuable features is crucial in pattern recognition. In this paper we deal with the issue that part of features originate from directional instead of common linear data. Both for directional and linear data a theory for a statistical modeling exists. However, none of these theories gives an integrated solution to problems, where linear and directional variables are to be combined in a single, multivariate probability density function. We describe a general approach for a unified statistical modeling, given the constraint that variances of the circular variables are small. The method is practically evaluated in the context of our online handwriting recognition system frog on hand and the so-called tangent slope angle feature. Recognition results are compared with two alternative modeling approaches. The proposed solution gives significant improvements in recognition accuracy, computational speed and memory requirements.  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