全文获取类型
收费全文 | 98208篇 |
免费 | 1762篇 |
国内免费 | 434篇 |
专业分类
电工技术 | 915篇 |
综合类 | 2357篇 |
化学工业 | 14599篇 |
金属工艺 | 5036篇 |
机械仪表 | 3313篇 |
建筑科学 | 2815篇 |
矿业工程 | 604篇 |
能源动力 | 1596篇 |
轻工业 | 4753篇 |
水利工程 | 1382篇 |
石油天然气 | 392篇 |
无线电 | 10282篇 |
一般工业技术 | 19058篇 |
冶金工业 | 4833篇 |
原子能技术 | 370篇 |
自动化技术 | 28099篇 |
出版年
2023年 | 165篇 |
2022年 | 359篇 |
2021年 | 573篇 |
2020年 | 376篇 |
2019年 | 383篇 |
2018年 | 14804篇 |
2017年 | 13695篇 |
2016年 | 10380篇 |
2015年 | 1056篇 |
2014年 | 808篇 |
2013年 | 1237篇 |
2012年 | 4065篇 |
2011年 | 10456篇 |
2010年 | 9003篇 |
2009年 | 6223篇 |
2008年 | 7495篇 |
2007年 | 8466篇 |
2006年 | 687篇 |
2005年 | 1689篇 |
2004年 | 1481篇 |
2003年 | 1537篇 |
2002年 | 865篇 |
2001年 | 308篇 |
2000年 | 362篇 |
1999年 | 259篇 |
1998年 | 261篇 |
1997年 | 214篇 |
1996年 | 226篇 |
1995年 | 187篇 |
1994年 | 165篇 |
1993年 | 155篇 |
1992年 | 130篇 |
1991年 | 96篇 |
1990年 | 122篇 |
1989年 | 117篇 |
1988年 | 89篇 |
1987年 | 93篇 |
1986年 | 100篇 |
1985年 | 100篇 |
1984年 | 88篇 |
1983年 | 76篇 |
1982年 | 96篇 |
1981年 | 90篇 |
1980年 | 71篇 |
1979年 | 70篇 |
1978年 | 62篇 |
1977年 | 74篇 |
1976年 | 61篇 |
1955年 | 71篇 |
1954年 | 79篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Takeshi Shiofuku Norihiro Abe Yoshihiro Tabuchi Hirokazu Taki Shoujie He 《Artificial Life and Robotics》2008,13(1):290-293
This paper presents an approach of measuring in real-time the vector of finger that is pointing to an object. DSP is used
in the operation processing unit in order to do the real-time processing. The steps include the extraction of flesh-colored
regions from an image, the labeling of the flesh-colored regions, and the detection of two characteristic positions on the
finger so that the direction that the finger is pointing at will be calculated. The entire process takes about 29 msec, which
makes it possible to have the frame rate of 34 fps. With this frame rate, this measurement approach is considered real-time
and promising to be merged into other application systems.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献
32.
Yanqing Ji Hao Ying John Yen Shizhuo Zhu Daniel C. Barth‐Jones Richard E. Miller R. Michael Massanari 《国际智能系统杂志》2007,22(8):827-845
Discovering unknown adverse drug reactions (ADRs) in postmarketing surveillance as early as possible is highly desirable. Nevertheless, current postmarketing surveillance methods largely rely on spontaneous reports that suffer from serious underreporting, latency, and inconsistent reporting. Thus these methods are not ideal for rapidly identifying rare ADRs. The multiagent systems paradigm is an emerging and effective approach to tackling distributed problems, especially when data sources and knowledge are geographically located in different places and coordination and collaboration are necessary for decision making. In this article, we propose an active, multiagent framework for early detection of ADRs by utilizing electronic patient data distributed across many different sources and locations. In this framework, intelligent agents assist a team of experts based on the well‐known human decision‐making model called Recognition‐Primed Decision (RPD). We generalize the RPD model to a fuzzy RPD model and utilize fuzzy logic technology to not only represent, interpret, and compute imprecise and subjective cues that are commonly encountered in the ADR problem but also to retrieve prior experiences by evaluating the extent of matching between the current situation and a past experience. We describe our preliminary multiagent system design and illustrate its potential benefits for assisting expert teams in early detection of previously unknown ADRs. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 827–845, 2007. 相似文献
33.
34.
Comments that a critical element in the final report of the American Psychological Association (APA) Task Force on the Victims of Crime and Violence may be lost simply because of the enormity and complexity of the issues involved. The real nature of the victim's emotional experience is often not directly addressed by researchers or service providers in the mental health community. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
35.
Journal of Materials Science Letters - 相似文献
36.
37.
38.
39.
Tony Maillet Jacques Barbier Jr. Daniel Duprez 《Applied catalysis. B, Environmental》1996,9(1-4):251-266
A 1% Pd catalyst (38% dispersion) was prepared by impregnating a γ-alumina with palladium acetylacetonate dissolved in acetone. The behaviour of this catalyst in oxidation and steam reforming (SR) of propane was investigated. Temperature-programmed reactions of C3H8 with O2 or with O2 + H2O were carried out with different stoichiometric ratios S(S =[O2]/5[C3H8]). The conversion profiles of C3H8 for the reaction carried out in substoichiometry of O2 (S < 1) showed two discrete domains of conversion: oxidation at temperatures below 350°C and SR at temperatures above 350°C. The presence of steam in the inlet gases is not necessary for SR to occur: there is sufficient water produced in the oxidation to form H2 and carbon oxides by this reaction. Contrary to what was observed with Pt, an apparent deactivation between 310 and 385°C could be observed with Pd in oxidation. This is due to a reduction of PdOx into Pd0, which is much less active than the oxide in propane oxidation. Steam added to the reactants inhibits oxidation while it prevents the reduction of PdOx into Pd0. Compared to Pt and to Rh, Pd has a higher thermal resistance: no deactivation occurred after treatment up to 700°C and limited deactivation after treatment up to 900°C, provided that the catalyst is maintained in an oxygen-rich atmosphere during the cooling. 相似文献
40.