全文获取类型
收费全文 | 12952篇 |
免费 | 941篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 79篇 |
综合类 | 8篇 |
化学工业 | 5178篇 |
金属工艺 | 128篇 |
机械仪表 | 298篇 |
建筑科学 | 456篇 |
矿业工程 | 18篇 |
能源动力 | 329篇 |
轻工业 | 3271篇 |
水利工程 | 112篇 |
石油天然气 | 70篇 |
无线电 | 470篇 |
一般工业技术 | 1692篇 |
冶金工业 | 536篇 |
原子能技术 | 35篇 |
自动化技术 | 1222篇 |
出版年
2024年 | 41篇 |
2023年 | 180篇 |
2022年 | 918篇 |
2021年 | 1046篇 |
2020年 | 425篇 |
2019年 | 438篇 |
2018年 | 483篇 |
2017年 | 512篇 |
2016年 | 555篇 |
2015年 | 455篇 |
2014年 | 591篇 |
2013年 | 880篇 |
2012年 | 848篇 |
2011年 | 950篇 |
2010年 | 738篇 |
2009年 | 672篇 |
2008年 | 613篇 |
2007年 | 588篇 |
2006年 | 455篇 |
2005年 | 343篇 |
2004年 | 284篇 |
2003年 | 256篇 |
2002年 | 238篇 |
2001年 | 143篇 |
2000年 | 95篇 |
1999年 | 127篇 |
1998年 | 107篇 |
1997年 | 107篇 |
1996年 | 100篇 |
1995年 | 73篇 |
1994年 | 58篇 |
1993年 | 58篇 |
1992年 | 65篇 |
1991年 | 46篇 |
1990年 | 38篇 |
1989年 | 33篇 |
1988年 | 33篇 |
1987年 | 31篇 |
1986年 | 41篇 |
1985年 | 36篇 |
1984年 | 26篇 |
1983年 | 22篇 |
1982年 | 15篇 |
1981年 | 16篇 |
1980年 | 19篇 |
1979年 | 19篇 |
1978年 | 20篇 |
1977年 | 13篇 |
1976年 | 7篇 |
1975年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
In this paper a new nonlinear feedback control law for continuous stirred tank reactors, obtained by exact Input/Output (I/O) linearization and Sontag's input‐to‐state stability feedback control redesign methods, is studied. By the new feedback control law, a significant attenuation of the disturbance effect is guaranteed, with evident improvement with respect to control laws obtained by the exact I/O linearization method. The performed simulations validate the theoretical results. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
93.
In this paper, we propose novel elastic graph matching (EGM) algorithms for face recognition assisted by the availability of 3D facial geometry. More specifically, we conceptually extend the EGM algorithm in order to exploit the 3D nature of human facial geometry for face recognition/verification. In order to achieve that, first we extend the matching module of the EGM algorithm in order to capitalize on the 2.5D facial data. Furthermore, we incorporate the 3D geometry into the multiscale analysis used and build a novel geodesic multiscale morphological pyramid of dilations/erosions in order to fill the graph jets. We show that the proposed advances significantly enhance the performance of EGM algorithms. We demonstrate the efficiency of the proposed advances in the face recognition/verification problem using photometric stereo. 相似文献
94.
95.
Victor M.R. Penichet Author Vitae Maria D. Lozano Author Vitae Author Vitae Ricardo Tesoriero Author Vitae 《Journal of Systems and Software》2010,83(8):1478-1488
Groupware applications have special features that, if they were taken into account from the very beginning, could reasonably improve the quality of the system. Such features concern human-computer-human interactions, i.e. a further step in the human-computer interaction field: communication, collaboration, cooperation and coordination, time, space, and awareness are issues to be considered. This paper presents a novel approach to gather requirements for groupware applications. The proposal is based on a methodology that includes the use of templates to gather the information regarding the different types of requirements. The requirements templates have been extended to include new information to give account of specific features concerning groupware applications. The information gathered is managed in a CASE tool we have developed; then general and specific diagrams are automatic or semi-automatically generated. 相似文献
96.
Juan José Alfaro Saiz Author Vitae Raúl Rodríguez Rodriguez Author VitaeAuthor Vitae Maria Jose Verdecho Author Vitae 《Computers in Industry》2010,61(7):676-685
Recently, much attention has been given to performance management within collaborative environments resulting in a wide variety of performance measurement/management frameworks. However, practically all of these frameworks present a common gap regarding the information treatment needs that support these frameworks. This issue is even more important in the case of Small and Medium-sized Enterprises (SMEs) due to their special characteristics. For that purpose, this paper presents an approach called Global Performance Management (GPM) Framework composed of a methodology, an information architecture and a technological solution, focusing mainly on the information architecture. The methodology guides SMEs when defining, developing, deploying and operating the GPM framework. The information architecture consists of a set of elements that support the tasks of collection, treatment and analysis of the used information, which complement the methodology to build a real model for the GPM framework. Finally, the technological solution bridges the engineering and conceptual environment, with the real-world operational and executable environment, following the path defined by the methodology. The information architecture was applied to two European pilots, achieving satisfactory results, which are highlighted in the paper as well as the main barriers encountered and solutions provided. 相似文献
97.
98.
Tomoko Watanabe Traphagan Yueh-hui Vanessa Chiang Hyeseung Maria Chang Benjaporn Wattanawaha Haekyung Lee Michael Charles Mayrath Jeongwon Woo Hyo-Jin Yoon Min Jung Jee Paul E. Resta 《Computers & Education》2010
Using a framework of cognitive, social, and teaching presence, the nature of learning experiences in a three-dimensional virtual world environment (Second Life) and a text-chat learning environment without visuals (TeachNet) were investigated. A mixed method of code frequencies, coherence graphs, interviews, and a survey was used. The results revealed that the TeachNet debates included more cognitive presence codes that indicate higher levels of cognitive processing than in SL debates. The teams were significantly different from each other in the collaboration style for developing arguments and in the ways to use utterances associated with cognitive, social, and teaching presences, and the groups’ collaboration style became more established with more experience with the tasks. The three critical factors–tool, tasks and group cohesion–that affect cognitive, teaching, and social presence are discussed. 相似文献
99.
We present empirical results of an auction-based algorithm for dynamic allocation of tasks to robots. The results have been obtained both in simulation and using real robots. A distinctive feature of our algorithm is its robustness to uncertainties and to robot malfunctions that happen during task execution, when unexpected obstacles, loss of communication, and other delays may prevent a robot from completing its allocated tasks. Therefore tasks not yet achieved are resubmitted for bids every time a task has been completed. This provides an opportunity to improve the allocation of the remaining tasks, enabling the robots to recover from failures and reducing the overall time for task completion. 相似文献
100.
Maria Elena Bruni Francesca Guerriero 《International Transactions in Operational Research》2010,17(2):207-220
The aim of this paper is to investigate the use of heuristic information to efficiently solve to optimality the robust shortest path problem. Starting from the exact algorithm proposed by Murty and Her, we describe how this algorithm can be enhanced by using heuristic rules and evaluation functions to guide the search. The efficiency of the proposed enhanced approach is tested over a range of random generated instances. Our computational results indicate that the use of heuristic criteria is able to speed up considerably the search and that the enhanced exact solution method outperforms the state‐of‐the‐art algorithm proposed by Murty and Her in most of the instances. 相似文献