全文获取类型
收费全文 | 946篇 |
免费 | 38篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 9篇 |
综合类 | 3篇 |
化学工业 | 102篇 |
金属工艺 | 11篇 |
机械仪表 | 40篇 |
建筑科学 | 47篇 |
能源动力 | 20篇 |
轻工业 | 73篇 |
水利工程 | 7篇 |
石油天然气 | 2篇 |
无线电 | 165篇 |
一般工业技术 | 189篇 |
冶金工业 | 200篇 |
原子能技术 | 4篇 |
自动化技术 | 123篇 |
出版年
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2019年 | 4篇 |
2018年 | 18篇 |
2017年 | 13篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 25篇 |
2013年 | 55篇 |
2012年 | 31篇 |
2011年 | 40篇 |
2010年 | 34篇 |
2009年 | 34篇 |
2008年 | 33篇 |
2007年 | 45篇 |
2006年 | 44篇 |
2005年 | 22篇 |
2004年 | 37篇 |
2003年 | 36篇 |
2002年 | 36篇 |
2001年 | 25篇 |
2000年 | 21篇 |
1999年 | 31篇 |
1998年 | 72篇 |
1997年 | 58篇 |
1996年 | 35篇 |
1995年 | 23篇 |
1994年 | 17篇 |
1993年 | 19篇 |
1992年 | 17篇 |
1991年 | 17篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 9篇 |
1987年 | 3篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 10篇 |
1973年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有995条查询结果,搜索用时 0 毫秒
991.
In this paper, extended object-oriented Petri nets (EOPNs) are proposed for the effective modelling of semiconductor wafer fabrication systems (SWFSs). To cope with their complexity in terms of the re-entrant process route and the mixed production mode, a special type of transition called main-bus gate is introduced, which may lead each kind of product to undergo every re-entrant processing stage. In addition, the hierarchical approach is also applied to cope with the complexity. An etching area that processes 0.25?µm logic IC products is taken as an illustration to present the detailed modelling procedures by EOPNs, and the resulting model validates that the EOPNs may cope well with complex SWFSs modelling. 相似文献
992.
One of the difficulties in modelling dynamic production systems is the representation of changes to the system along time. Coloured Petri nets with changeable structure (CPN-CS) are capable of modelling systems subject to change. However, this is restricted to functionality modelling of the system. In this paper, we extend CPN-CSs into temporized CPN-CS (TCPN-CS). The extension is carried out by associating relevant modelling elements with time parameters and modifying the mechanism for structure change of the CPN-CS model. TCPN-CS makes it possible to model a dynamic production system considering both functionality and performance. A case study is provided to show that TCPN-CS is effective for modelling dynamic production systems. 相似文献
993.
994.
R. K. Wong T. Fung K. S. Leung Y. Leung 《International journal of remote sensing》2013,34(11):2427-2436
A 'loss-effective' compression method which based on the change detection of raw image data is proposed for dealing with a sequence of satellite images. The average compression ratio we gained, compared with some typical satellite image formats, is about 2:1 to 3 :1. This sounds not so impressive when compared with the most current compression techniques which used in multimedia processing. However, some information will be lost in those methods, while our approach is information-loss effective, which is crucial for further satellite image analysis. Moreover, the framework can be combined with different compression algorithms to obtain different trade-offs between the compression ratio and the computation time. Experimental results based on real satellite images are included. Finally, other issues including the further optimization of the methods and some other possible applications of the method are discussed. 相似文献
995.
Professor Gordon McKay has a long,exciting and distinguished professional career as a chemical engineer.From his early days in industry through to his most recent appointment as professor and Acting Head of Department of Chemical and Biomolecular Engineering at the Hong Kong University of Science and Technology(HKUST),he has made a substantial contribution to the profession.Professor 相似文献