全文获取类型
收费全文 | 419011篇 |
免费 | 4086篇 |
国内免费 | 981篇 |
专业分类
电工技术 | 7074篇 |
综合类 | 272篇 |
化学工业 | 65530篇 |
金属工艺 | 19227篇 |
机械仪表 | 13046篇 |
建筑科学 | 9349篇 |
矿业工程 | 3258篇 |
能源动力 | 8989篇 |
轻工业 | 32995篇 |
水利工程 | 5292篇 |
石油天然气 | 13190篇 |
武器工业 | 24篇 |
无线电 | 42849篇 |
一般工业技术 | 86927篇 |
冶金工业 | 73547篇 |
原子能技术 | 12289篇 |
自动化技术 | 30220篇 |
出版年
2021年 | 3371篇 |
2018年 | 5980篇 |
2017年 | 6038篇 |
2016年 | 6474篇 |
2015年 | 3815篇 |
2014年 | 6538篇 |
2013年 | 17132篇 |
2012年 | 10219篇 |
2011年 | 13458篇 |
2010年 | 11013篇 |
2009年 | 12471篇 |
2008年 | 12868篇 |
2007年 | 12724篇 |
2006年 | 11088篇 |
2005年 | 10303篇 |
2004年 | 9707篇 |
2003年 | 9385篇 |
2002年 | 9375篇 |
2001年 | 9236篇 |
2000年 | 8891篇 |
1999年 | 8825篇 |
1998年 | 20656篇 |
1997年 | 15271篇 |
1996年 | 11719篇 |
1995年 | 8909篇 |
1994年 | 7994篇 |
1993年 | 7961篇 |
1992年 | 6220篇 |
1991年 | 6211篇 |
1990年 | 6116篇 |
1989年 | 6055篇 |
1988年 | 5983篇 |
1987年 | 5208篇 |
1986年 | 5259篇 |
1985年 | 5900篇 |
1984年 | 5619篇 |
1983年 | 5247篇 |
1982年 | 4885篇 |
1981年 | 5196篇 |
1980年 | 4898篇 |
1979年 | 5066篇 |
1978年 | 5206篇 |
1977年 | 5752篇 |
1976年 | 7368篇 |
1975年 | 4781篇 |
1974年 | 4673篇 |
1973年 | 4711篇 |
1972年 | 4206篇 |
1971年 | 3833篇 |
1970年 | 3342篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
G. A. Zeinalova A. E. Mushailov A. Kh. Mamedova É. A. Nagieva 《Chemistry and Technology of Fuels and Oils》1989,25(2):78-80
Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 2, pp. 14–15, February, 1989. 相似文献
92.
Dr. G. Pönisch 《Computing》1987,39(1):1-17
A direct method is described for computing a hysteresis point (double turning point) corresponding to a cusp point of a system ofn nonlinear equations inn variables depending on two parameters. By addition of two equations a minimally extended system ofn+2 nonlinear equations is constructed for which the hysteresis point is an isolated solution. An efficient implementation of Newton's method is presented not requiring evaluations of second derivatives of the original problem. Two numerical examples show the efficiency of theQ-quadratically convergent method. 相似文献
93.
Consideration was given to the decision making procedures based on the fuzzy messages of experts whose preferences on the set of collective decisions can also be fuzzy. 相似文献
94.
95.
I. N. Polandov V. K. Novik O. K. Gulish B. P. Bogomolov V. B. Morozov 《Measurement Techniques》1989,32(9):888-890
Translated from Izmeritel'naya Tekhnika, No. 9, pp. 34–35, September, 1989. 相似文献
96.
97.
We have designed, developed, and tested a very promising thermal image analysis method for polygraph testing. The method achieved a correct classification rate of CCR= 84% on the test population to our avail. This method, once refined, can serve as an additional channel for increasing the reliability and accuracy of traditional polygraph examination. We extract subtle facial temperature fluctuation patterns through nonlinear heat transfer modeling. The modeling transforms raw thermal data to blood flow rate information. Then, we use the slope of the average periorbital blood flow rate as the feature of a binary classification scheme. The results come to support our previous laboratory findings about the importance of periorbital blood flow in anxious states. 相似文献
98.
99.
Fuzzy logic was first suggested as the mechanism by which humans drive cars. This paper addresses the use of fuzzy logic and algorithms towards the intelligent autonomous motion control of land vehicles. To cope with vehicle complexities, internal parametric changes, and with unpredictable environmental effects, the controllers that are presented, whilst heuristic in nature, are self-organizing or self-learning in that they generate automatically by observation an experiential rule base that models the vehicle, and via an appropriate performance index an optimal control rule base that is robust to large parametric changes. The methodology presented is applicable to any complex process which is too difficult to model or control using conventional methods, or which has relied on the experience of a human operator. An overview of fuzzy logic and static fuzzy logic control (akin to expert systems) is provided, together with illustrative examples. 相似文献
100.
Translated from Atomnaya Énergiya, Vol. 67, No. 2, pp. 97–100, August, 1989. 相似文献