全文获取类型
收费全文 | 452356篇 |
免费 | 4978篇 |
国内免费 | 1311篇 |
专业分类
电工技术 | 7914篇 |
综合类 | 297篇 |
化学工业 | 70234篇 |
金属工艺 | 19926篇 |
机械仪表 | 14179篇 |
建筑科学 | 10180篇 |
矿业工程 | 3517篇 |
能源动力 | 10577篇 |
轻工业 | 36309篇 |
水利工程 | 5492篇 |
石油天然气 | 12609篇 |
武器工业 | 36篇 |
无线电 | 48920篇 |
一般工业技术 | 92715篇 |
冶金工业 | 79949篇 |
原子能技术 | 12116篇 |
自动化技术 | 33675篇 |
出版年
2021年 | 3796篇 |
2019年 | 3609篇 |
2018年 | 6586篇 |
2017年 | 6583篇 |
2016年 | 7076篇 |
2015年 | 4319篇 |
2014年 | 7277篇 |
2013年 | 19244篇 |
2012年 | 11447篇 |
2011年 | 15100篇 |
2010年 | 12263篇 |
2009年 | 13888篇 |
2008年 | 14234篇 |
2007年 | 14048篇 |
2006年 | 12273篇 |
2005年 | 11334篇 |
2004年 | 10503篇 |
2003年 | 10144篇 |
2002年 | 10069篇 |
2001年 | 10061篇 |
2000年 | 9543篇 |
1999年 | 9667篇 |
1998年 | 23503篇 |
1997年 | 17118篇 |
1996年 | 13218篇 |
1995年 | 10006篇 |
1994年 | 8848篇 |
1993年 | 8971篇 |
1992年 | 6854篇 |
1991年 | 6805篇 |
1990年 | 6514篇 |
1989年 | 6511篇 |
1988年 | 6438篇 |
1987年 | 5514篇 |
1986年 | 5580篇 |
1985年 | 6357篇 |
1984年 | 6026篇 |
1983年 | 5616篇 |
1982年 | 5215篇 |
1981年 | 5300篇 |
1980年 | 5205篇 |
1979年 | 5139篇 |
1978年 | 5251篇 |
1977年 | 5826篇 |
1976年 | 7277篇 |
1975年 | 4770篇 |
1974年 | 4536篇 |
1973年 | 4641篇 |
1972年 | 4056篇 |
1971年 | 3703篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
81.
N. M. Sanghavi Hema Venkatesh Varsha Tandel 《Drug development and industrial pharmacy》1994,20(7):1275-1283
Gilbenclamide, a widely used potent hypoglycaemic agent was solubllized using β -Cyclodextrin and β -Cyclodextrin derivatives. Complexes were prepared by kneading method in a molar ratio of 1:1 of the drug and the cyclodextrlns respectively. The Glibenclamide β -Cyelocextrin complex was characterized and evaluated by I.R. studies, Differential Scanning Calorimotry 6 X-ray diffractometry. The in-vitro dissolution rates of drug from inclusion complexes of β Cyclodextrins and its derivatives were compared. A significant Improvement In dissolution lor, rates of Gllbenclamide was observed with Inclusion complexes of all the Cyclodextrins. However, the solubilizing effect was more in case of β-Cyclodextrin derivatives. 相似文献
82.
A distributed problem solving system can be characterized as a group of individual cooperating agents running to solve common problems. As dynamic application domains continue to grow in scale and complexity, it becomes more difficult to control the purposeful behavior of agents, especially when unexpected events may occur. This article presents an information and knowledge exchange framework to support distributed problem solving. From the application viewpoint the article concentrates on the stock trading domain; however, many presented solutions can be extended to other dynamic domains. It addresses two important issues: how individual agents should be interconnected so that their resources are efficiently used and their goals accomplished effectively; and how information and knowledge transfer should take place among the agents to allow them to respond successfully to user requests and unexpected external situations. The article introduces an architecture, the MASST system architecture, which supports dynamic information and knowledge exchange among the cooperating agents. The architecture uses a dynamic blackboard as an interagent communication paradigm to facilitate factual data, business rule, and command exchange between cooperating MASST agents. The critical components of the MASST architecture have been implemented and tested in the stock trading domain, and have proven to be a viable solution for distributed problem solving based on cooperating agents 相似文献
83.
84.
Translated from Atomnaya Énergiya, Vol. 66, No. 6, pp. 423–424, June, 1989. 相似文献
85.
A. A. Konstantinov N. V. Kurenkov A. B. Malinin T. E. Sazonova S. V. Sepman 《Atomic Energy》1989,67(3):696-698
Translated from Atomnaya Énergiya, Vol. 67, No. 3, pp. 215–216, September, 1989. 相似文献
86.
N.C. Knowles 《Nuclear Engineering and Design》1989,116(1)
Geomechanical aspects of the storage of radioactive waste in salt formations have been studied extensively using finite element methods over the last 20 years. In consequence a range of computer programs and associated modelling techniques have been assembled. The paper is based on a benchmark exercise to compare the predictive abilities of a number of these programs and highlights the difficulties of making reliable a-priori estimates of long term behaviour. 相似文献
87.
Nagpal R. Zambonelli F. Sirer E.G. Chaouchi H. Smirnov M. 《Intelligent Systems, IEEE》2006,21(2):50-58
No generally accepted principles and guidelines currently exist to help engineers design local interaction mechanisms that result in a desired global behavior. However, several communities have developed ways of approaching this problem in the context of niched application areas. Because the ideas underlying these approaches are often obscured or underemphasized in technical papers, the authors review the role of self-organization in their work. They provide a better picture of the status of the emerging field of self-organizing systems or autonomic computing. 相似文献
88.
89.
This paper deals with the technical feasibility and economic viability of a grid connected wind-energy conversion system (WECS) used to cover the energy demand of an average habitable dwelling. The various parts of the wind-energy system are described and the useful electrical energy production is determined using a simulation program based on the Monte Carlo method. An economic analysis of the WEC system is performed using a computerized assessment tool. Important financial indices are calculated and financial scenarios investigated. 相似文献
90.
A method for fabricating single crystal blades that combines the techniques of seed crystals and selection is suggested. The method realizes the advantages of both techniques, i.e., the high structural perfection and the possibility of fabricating single crystals with specified spatial orientation. Metallographic and x-ray diffraction analyses are used to study the processes of nucleation of the single crystal structure of blade castings fabricated from high-temperature nickel alloys by the method of selection and seed crystals. A commercial process for fabricating cast single crystal turbine blades by the new method is suggested. 相似文献