全文获取类型
收费全文 | 15508篇 |
免费 | 224篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 184篇 |
综合类 | 5篇 |
化学工业 | 1501篇 |
金属工艺 | 414篇 |
机械仪表 | 186篇 |
建筑科学 | 415篇 |
矿业工程 | 13篇 |
能源动力 | 235篇 |
轻工业 | 664篇 |
水利工程 | 108篇 |
石油天然气 | 30篇 |
无线电 | 723篇 |
一般工业技术 | 1238篇 |
冶金工业 | 1079篇 |
原子能技术 | 129篇 |
自动化技术 | 8815篇 |
出版年
2023年 | 35篇 |
2022年 | 78篇 |
2021年 | 102篇 |
2020年 | 91篇 |
2019年 | 97篇 |
2018年 | 112篇 |
2017年 | 126篇 |
2016年 | 120篇 |
2015年 | 138篇 |
2014年 | 391篇 |
2013年 | 571篇 |
2012年 | 1093篇 |
2011年 | 2670篇 |
2010年 | 1382篇 |
2009年 | 1267篇 |
2008年 | 1094篇 |
2007年 | 932篇 |
2006年 | 738篇 |
2005年 | 878篇 |
2004年 | 763篇 |
2003年 | 799篇 |
2002年 | 482篇 |
2001年 | 117篇 |
2000年 | 90篇 |
1999年 | 110篇 |
1998年 | 113篇 |
1997年 | 92篇 |
1996年 | 114篇 |
1995年 | 84篇 |
1994年 | 86篇 |
1993年 | 78篇 |
1992年 | 65篇 |
1991年 | 48篇 |
1990年 | 57篇 |
1989年 | 75篇 |
1988年 | 39篇 |
1987年 | 51篇 |
1986年 | 45篇 |
1985年 | 60篇 |
1984年 | 61篇 |
1983年 | 54篇 |
1982年 | 44篇 |
1981年 | 48篇 |
1980年 | 28篇 |
1979年 | 38篇 |
1978年 | 32篇 |
1977年 | 24篇 |
1976年 | 21篇 |
1975年 | 28篇 |
1974年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Brian Dipert 《电子设计技术》2008,15(6):60-60,62,64,66
认为蜂窝系统是未来收看移动电视的唯一方法很可能是不对的。开路电视广播和卫星电视服务提供商也希望能在移动电视浪潮中成功获利。 相似文献
12.
13.
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
14.
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
15.
16.
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
17.
Lash Steven J.; Stephens Robert S.; Burden Jennifer L.; Grambow Steven C.; DeMarce Josephine M.; Jones Mark E.; Lozano Brian E.; Jeffreys Amy S.; Fearer Stephanie A.; Horner Ronnie D. 《Canadian Metallurgical Quarterly》2007,21(3):387
Although continuing care is strongly related to positive treatment outcomes for substance use disorder (SUD), participation rates are low and few effective interventions are available. In a randomized clinical trial with 150 participants (97% men), 75 graduates of a residential Veterans Affairs Medical Center SUD program who received an aftercare contract, attendance prompts, and reinforcers (CPR) were compared to 75 graduates who received standard treatment (STX). Among CPR participants, 55% completed at least 3 months of aftercare, compared to 36% in STX. Similarly, CPR participants remained in treatment longer than those in STX (5.5 vs. 4.4 months). Additionally, CPR participants were more likely to be abstinent compared to STX (57% vs. 37%) after 1 year. The CPR intervention offers a practical means to improve adherence among individuals in SUD treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
18.
Hitsman Brian; Borrelli Belinda; McChargue Dennis E.; Spring Bonnie; Niaura Raymond 《Canadian Metallurgical Quarterly》2003,71(4):657
The authors conducted a meta-analysis of published studies to (a) evaluate the premise that a history of major depression is associated with failure to quit smoking and (b) identify factors that moderate the relationship between history of depression and cessation outcome. Fifteen studies met the selection requirements and were coded for various study methodology and treatment characteristics. DSTAT was used to calculate individual study effect sizes, determine the mean effect size across studies. and test for moderator effects. No differences in either short-term (≤ 3 months) or long-term abstinence rates (≥ 6 months) were observed between smokers positive versus negative for history of depression. Lifetime history of major depression does not appear to be an independent risk factor for cessation failure in smoking cessation treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
19.
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
20.