全文获取类型
收费全文 | 789篇 |
免费 | 22篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 812篇 |
出版年
2023年 | 7篇 |
2022年 | 13篇 |
2021年 | 17篇 |
2020年 | 10篇 |
2019年 | 9篇 |
2018年 | 20篇 |
2017年 | 21篇 |
2016年 | 23篇 |
2015年 | 17篇 |
2014年 | 26篇 |
2013年 | 57篇 |
2012年 | 22篇 |
2011年 | 46篇 |
2010年 | 25篇 |
2009年 | 26篇 |
2008年 | 36篇 |
2007年 | 32篇 |
2006年 | 25篇 |
2005年 | 18篇 |
2004年 | 21篇 |
2003年 | 25篇 |
2002年 | 18篇 |
2001年 | 22篇 |
2000年 | 8篇 |
1999年 | 19篇 |
1998年 | 40篇 |
1997年 | 23篇 |
1996年 | 21篇 |
1995年 | 18篇 |
1994年 | 16篇 |
1993年 | 11篇 |
1992年 | 11篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 14篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 14篇 |
1984年 | 3篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 12篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1973年 | 3篇 |
1963年 | 1篇 |
排序方式: 共有812条查询结果,搜索用时 0 毫秒
1.
2.
Michael V. Antony 《Minds and Machines》1991,1(3):321-341
Fodor and Pylyshyn (1988) have argued that the cognitive architecture is not Connectionist. Their argument takes the following form: (1) the cognitive architecture is Classical; (2) Classicalism and Connectionism are incompatible; (3) therefore the cognitive architecture is not Connectionist. In this essay I argue that Fodor and Pylyshyn's defenses of (1) and (2) are inadequate. Their argument for (1), based on their claim that Classicalism best explains the systematicity of cognitive capacities, is an invalid instance of inference to the best explanation. And their argument for (2) turns out to be question-begging. The upshot is that, while Fodor and Pylyshyn have presented Connectionists with the important empirical challenge of explaining systematicity, they have failed to provide sufficient reason for inferring that the cognitive architecture is Classical and not Connectionist. 相似文献
3.
The crystallization behaviour of three amorphous alloys, Co50Ni25Si15B10, Ni50Co25Si15B10 and Ni50Co25P15B10, was studied by means of differential thermal analysis in conjunction with scanning transmission electron microscopy. Isochronal annealing showed a strong dependence of crystallization on scan rate over the range of 1.99 to 20.70 K min–1. At high Co/Ni ratios, a sequential two-stage crystallization process involving primary MS-I phase followed by MS-II phase precipitation was observed. At low Co/Ni ratios MS-I and MS-II crystallization were concurrent and inseparable. Replacement of the metalloid Si with P as the glass-former dramatically reduced the activation energy for crystallization as well as the crystallization temperature. A mechanistic understanding of these findings was pursued in light of TEM/STEM microanalysis 相似文献
4.
5.
6.
7.
It is shown, by means of Lagrangian momentum and power balances across the slug nose in slug flow, that the power dissipated due to sudden expansion of the fluid in the film immediately downstream of the slug nose is greater than the power lost due to viscous action at the pipe wall but that it may not be large enough to materially aid particle transport. This has the implication that sand transport in intermittent flow may be considered as transport in a hybrid flow of hydraulic conveying and stratified flow when the length of the mixing section at the slug nose is short compared to the length of the slug body. 相似文献
8.
M J Scotter S A Thorpe S L Reynolds L A Wilson D J Lewis 《Food Additives & Contaminants》1992,9(3):237-242
Retail samples of livers from calf (23), ox (18), lamb (17), pig (15), chicken (16) and turkey (1) were analysed to determine levels of vitamin A (all trans-retinol) and to aid assessment of the effects of using vitamin supplemented compound feedingstuffs for livestock. For comparison, 22 liver samples from lambs reared on diets not containing vitamin-supplemented compound feedingstuffs and four samples of liver from ox which had received supplemented feed but not during the last four months prior to slaughter were also analysed. The chosen method of analysis utilized saponification, solvent extraction and normal-phase high performance liquid chromatography with fluorescence detection. For all species analysed, the levels of vitamin A ranged from 10 to 1100 mg/kg, with all but seven at or below 400 mg/kg. For lamb and ox livers, the mean levels were 310 mg/kg and 200 mg/kg respectively for retail samples. The mean levels were 220 mg/kg (lamb) and 120 mg/kg (ox) in liver samples from animals fed controlled diets. The results are of the same order as those reported over recent years. 相似文献
9.
10.
Vision and navigation for the Carnegie-Mellon Navlab 总被引:7,自引:0,他引:7
Thorpe C. Hebert M.H. Kanade T. Shafer S.A. 《IEEE transactions on pattern analysis and machine intelligence》1988,10(3):362-373
A distributed architecture articulated around the CODGER (communication database with geometric reasoning) knowledge database is described for a mobile robot system that includes both perception and navigation tools. Results are described for vision and navigation tests using a mobile testbed that integrates perception and navigation capabilities that are based on two types of vision algorithms: color vision for road following, and 3-D vision for obstacle detection and avoidance. The perception modules are integrated into a system that allows the vehicle to drive continuously in an actual outdoor environment. The resulting system is able to navigate continuously on roads while avoiding obstacles 相似文献