全文获取类型
收费全文 | 565952篇 |
免费 | 7054篇 |
国内免费 | 1003篇 |
专业分类
电工技术 | 10508篇 |
综合类 | 466篇 |
化学工业 | 90063篇 |
金属工艺 | 23335篇 |
机械仪表 | 18499篇 |
建筑科学 | 12529篇 |
矿业工程 | 4312篇 |
能源动力 | 14429篇 |
轻工业 | 45767篇 |
水利工程 | 6941篇 |
石油天然气 | 14961篇 |
武器工业 | 39篇 |
无线电 | 60277篇 |
一般工业技术 | 116222篇 |
冶金工业 | 95557篇 |
原子能技术 | 14681篇 |
自动化技术 | 45423篇 |
出版年
2021年 | 5483篇 |
2019年 | 5268篇 |
2018年 | 9202篇 |
2017年 | 9410篇 |
2016年 | 9832篇 |
2015年 | 6025篇 |
2014年 | 10244篇 |
2013年 | 26104篇 |
2012年 | 15774篇 |
2011年 | 21090篇 |
2010年 | 16970篇 |
2009年 | 18817篇 |
2008年 | 19069篇 |
2007年 | 18768篇 |
2006年 | 16286篇 |
2005年 | 14743篇 |
2004年 | 14008篇 |
2003年 | 13691篇 |
2002年 | 13247篇 |
2001年 | 12852篇 |
2000年 | 12330篇 |
1999年 | 12011篇 |
1998年 | 27650篇 |
1997年 | 20039篇 |
1996年 | 15627篇 |
1995年 | 12005篇 |
1994年 | 10859篇 |
1993年 | 10616篇 |
1992年 | 8333篇 |
1991年 | 8102篇 |
1990年 | 7990篇 |
1989年 | 7763篇 |
1988年 | 7479篇 |
1987年 | 6748篇 |
1986年 | 6533篇 |
1985年 | 7390篇 |
1984年 | 6700篇 |
1983年 | 6437篇 |
1982年 | 5779篇 |
1981年 | 5897篇 |
1980年 | 5630篇 |
1979年 | 5733篇 |
1978年 | 5663篇 |
1977年 | 6178篇 |
1976年 | 7685篇 |
1975年 | 5108篇 |
1974年 | 4903篇 |
1973年 | 4980篇 |
1972年 | 4279篇 |
1971年 | 4038篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
943.
The basic characteristics of the multi-effect boiling (MEB) desalination system are presented. Recent developments are considered, and a thermodynamic analysis and evaluation of the heat transfer areas required for the MEB system are given. In comparing the heat transfer areas, water pretreatment and salt concentration, pumping power requirement and stability of the MEB and multi-stage flash (MSF) systems, MEB seems to have definite advantages over MSF. However, in the absence of well-proven large capacity MEB units, and in view of the good experience with and reliability of MSF systems, large producers of desalted water favor continued installation of MSF systems. 相似文献
944.
945.
946.
Computing must become much more human centered--for example, by presenting personalized information to users and by respecting personal preferences when controlling multiple devices or invoking various services. Appropriate representation of the information's semantics and of the functionality of devices and services will be critical to such personalized computing. Symbolic artificial intelligence techniques provide the method of choice for the required semantic-representation and reasoning capabilities. 相似文献
947.
/sup T/he University of Minnesota's Scout is a small cylindrical robot capable of rolling and jumping. Models describing the robot's motion are developed. These models can be employed for motion prediction and simulation. The results suggest that the determining factor of the Scout's behavior is the length of the winch cable. 相似文献
948.
The authors argued that AI systems must be able to manipulate their own internal representations automatically to deal with an infinitely complex and ever-changing world and to scale up to rich, complex applications. Such manipulation must go beyond changing beliefs and learning new concepts in terms of old concepts; it must be able to change ontology's underlying syntax and semantics. Initial progress has been made, but further progress is urgently needed owing to the demands of autonomous multiagent systems. Understanding and implementing this ability must be a major focus of AI for the next 50 years. 相似文献
949.
Design and Implementation of a Flexible Manufacturing Control System Using Neural Network 总被引:1,自引:0,他引:1
Magdy M. Abdelhameed Farid A. Tolbah 《International Journal of Flexible Manufacturing Systems》2002,14(3):263-279
Design and implementation of a sequential controller based on the concept of artificial neural networks for a flexible manufacturing system are presented. The recurrent neural network (RNN) type is used for such a purpose. Contrary to the programmable controller, an RNN-based sequential controller is based on a definite mathematical model rather than depending on experience and trial and error techniques. The proposed controller is also more flexible because it is not limited by the restrictions of the finite state automata theory. Adequate guidelines of how to construct an RNN-based sequential controller are presented. These guidelines are applied to different case studies. The proposed controller is tested by simulations and real-time experiments. These tests prove the successfulness of the proposed controller performances. Theoretical as well as experimental results are presented and discussed indicating that the proposed design procedure using Elman's RNN can be effective in designing a sequential controller for event-based type manufacturing systems. In addition, the simulation results assure the effectiveness of the proposed controller to outperform the effect of noisy inputs. 相似文献
950.