全文获取类型
收费全文 | 25711篇 |
免费 | 2372篇 |
国内免费 | 1196篇 |
专业分类
电工技术 | 1110篇 |
技术理论 | 3篇 |
综合类 | 3125篇 |
化学工业 | 2165篇 |
金属工艺 | 633篇 |
机械仪表 | 889篇 |
建筑科学 | 6368篇 |
矿业工程 | 2089篇 |
能源动力 | 792篇 |
轻工业 | 859篇 |
水利工程 | 1646篇 |
石油天然气 | 832篇 |
武器工业 | 261篇 |
无线电 | 1267篇 |
一般工业技术 | 1454篇 |
冶金工业 | 1985篇 |
原子能技术 | 217篇 |
自动化技术 | 3584篇 |
出版年
2024年 | 57篇 |
2023年 | 274篇 |
2022年 | 662篇 |
2021年 | 753篇 |
2020年 | 723篇 |
2019年 | 578篇 |
2018年 | 496篇 |
2017年 | 661篇 |
2016年 | 760篇 |
2015年 | 873篇 |
2014年 | 1586篇 |
2013年 | 1375篇 |
2012年 | 1570篇 |
2011年 | 1960篇 |
2010年 | 1598篇 |
2009年 | 1714篇 |
2008年 | 1565篇 |
2007年 | 1941篇 |
2006年 | 1746篇 |
2005年 | 1486篇 |
2004年 | 1264篇 |
2003年 | 1149篇 |
2002年 | 1003篇 |
2001年 | 763篇 |
2000年 | 657篇 |
1999年 | 499篇 |
1998年 | 319篇 |
1997年 | 273篇 |
1996年 | 214篇 |
1995年 | 152篇 |
1994年 | 155篇 |
1993年 | 104篇 |
1992年 | 75篇 |
1991年 | 51篇 |
1990年 | 51篇 |
1989年 | 33篇 |
1988年 | 34篇 |
1987年 | 18篇 |
1986年 | 11篇 |
1985年 | 13篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1966年 | 3篇 |
1962年 | 2篇 |
1959年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
61.
62.
Fumio Negoro 《Knowledge》2003,16(7-8):383-397
The purpose of our study is to build up relationships between requirement and source programs with our originally thought-out rules. When other rules to be derived from these original rules are applied to software development, even a single instruction in a programming language could be determined, and the program would satisfy the requirement. More specifically speaking, these rules will turn into a formula or a prototype of software programs. Hence, when the variables in the requirement are placed in the formula, we can get a required program in an automatic way. 相似文献
63.
绿色植物能吸收CO2 ,释放O2 ,清除有毒污染物 ,阻滞灰尘 ,杀灭细菌等致病微生物 ;在矿区环境污染治理时 ,应切实加强矿区绿化工作 ,扩大植被覆盖率 ,保持矿区生态平衡 ,促进矿区的可持续发展。 相似文献
64.
Maarja Kruusmaa 《Journal of Intelligent and Robotic Systems》2003,38(1):55-83
This paper presents a self-adapting approach to global level path planning in dynamic environments. The aim of this work is to minimize risk and delays in possible applications of mobile robots (e.g., in industrial processes). We introduce a hybrid system that uses case-based reasoning as well as grid-based maps for decision-making. Maps are used to suggest several alternative paths between specific start and goal point. The casebase stores these solutions and remembers their characteristics. Environment representation and casebase design are discussed. To solve the problem of exploration vs. exploitation, a decision-making strategy is proposed that is based on the irreversibility of decisions. Forgetting strategies are discussed and evaluated in the context of case-based maintenance. The adaptability of the system is evaluated in a domain based on real sensor data with simulated occupancy probabilities. Forgetting strategies and decision-making strategies are evaluated in simulated environments. Experiments show that a robot is able to adapt in dynamic environments and can learn to use paths that are less risky to follow. 相似文献
65.
66.
67.
简述了攀钢含铁尘泥的基本特性、攀钢含铁尘泥利用技术现状及存在的问题。根据目前国内外钢铁企业含铁尘泥综合利用技术的动态、经验,并结合攀钢的实际情况,提出了攀钢含铁尘泥利用技术的发展方向。 相似文献
68.
No authorship indicated 《Canadian Metallurgical Quarterly》2004,59(5):352
The 2004 Gold Medal Award for Life Achievement in the Application of Psychology was awarded to Edwin A. Fleishman, for his significant contributions to the science and applications of psychology, which he has sustained over his remarkable career. He is cited for his research, which has had a profound influence on our understanding of human capabilities, their measurement, their development, and their application in the world of work. Through his many influential leadership roles, as president of the International Association of Applied Psychology and three divisions of the American Psychological Association, and as editor of the Journal of Applied Psychology, he has helped shape our profession. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
69.
70.