全文获取类型
收费全文 | 10235篇 |
免费 | 55篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 139篇 |
综合类 | 1篇 |
化学工业 | 655篇 |
金属工艺 | 313篇 |
机械仪表 | 82篇 |
建筑科学 | 49篇 |
矿业工程 | 2篇 |
能源动力 | 84篇 |
轻工业 | 80篇 |
水利工程 | 10篇 |
石油天然气 | 13篇 |
无线电 | 409篇 |
一般工业技术 | 270篇 |
冶金工业 | 104篇 |
原子能技术 | 90篇 |
自动化技术 | 7997篇 |
出版年
2024年 | 5篇 |
2023年 | 19篇 |
2022年 | 41篇 |
2021年 | 57篇 |
2020年 | 33篇 |
2019年 | 33篇 |
2018年 | 65篇 |
2017年 | 53篇 |
2016年 | 50篇 |
2015年 | 37篇 |
2014年 | 257篇 |
2013年 | 253篇 |
2012年 | 825篇 |
2011年 | 2319篇 |
2010年 | 1154篇 |
2009年 | 991篇 |
2008年 | 704篇 |
2007年 | 608篇 |
2006年 | 463篇 |
2005年 | 591篇 |
2004年 | 531篇 |
2003年 | 590篇 |
2002年 | 294篇 |
2001年 | 13篇 |
2000年 | 11篇 |
1999年 | 18篇 |
1998年 | 26篇 |
1997年 | 15篇 |
1996年 | 18篇 |
1995年 | 11篇 |
1994年 | 7篇 |
1993年 | 16篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 15篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 14篇 |
1985年 | 8篇 |
1984年 | 15篇 |
1983年 | 9篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 14篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 8篇 |
1975年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
In this paper, we consider the classical finite mixture model, which is an effective tool for modeling lifetime distributions for random samples from heterogeneous populations. We discuss new results on stochastic comparison for two finite mixtures when each of them is drawn from one of the following semiparametric families, i.e., proportional hazards, accelerated lifetime and proportional reversed hazards. 相似文献
2.
Navab SinghAuthor Vitae Moitreyee Mukherjee-RoyAuthor VitaeSohan Singh MehtaAuthor Vitae 《Microelectronics Journal》2003,34(4):237-245
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
3.
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
4.
5.
Chia-Jung Pai Author Vitae Author Vitae Yu-Ming Liang Author Vitae Author Vitae Sei-Wang Chen Author Vitae 《Pattern recognition》2004,37(5):1025-1034
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
6.
V. Rodin Author Vitae A. Benzinou Author VitaeAuthor Vitae P. Ballet Author VitaeAuthor Vitae J. Tisseau Author VitaeAuthor Vitae 《Pattern recognition》2004,37(4):631-645
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
7.
8.
N. E. Wijeysundera M. N. A. Hawlader Chan Wee Boon Andy M. Kamal Hossain 《International Journal of Refrigeration》2004,27(5):1997
An ice slurry generation system was developed using direct contact heat transfer between water and the coolant, Fluroinert FC-84. The location of the coolant nozzle is an important design consideration to avoid clogging due to freezing of water. An ice fraction of up to about 40 percent was obtained with the nozzle located at the bottom of the ice slurry tank and the jet directed upwards into the water. Two simplified model were developed to extract the heat transfer coefficient between the coolant drops and the water. The first model requires as input the average drop diameter and the residence time while the second model uses the measured drop diameter distribution. The estimated heat transfer coefficients are much smaller than those computed using single-sphere correlations. 相似文献
9.
Er-Wei Bai Author Vitae 《Automatica》2003,39(9):1521-1530
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
10.
Qing-Chang Zhong Author Vitae 《Automatica》2003,39(3):499-508
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