全文获取类型
收费全文 | 4128篇 |
免费 | 185篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 36篇 |
综合类 | 6篇 |
化学工业 | 950篇 |
金属工艺 | 39篇 |
机械仪表 | 74篇 |
建筑科学 | 337篇 |
矿业工程 | 12篇 |
能源动力 | 125篇 |
轻工业 | 444篇 |
水利工程 | 45篇 |
石油天然气 | 11篇 |
武器工业 | 1篇 |
无线电 | 267篇 |
一般工业技术 | 650篇 |
冶金工业 | 463篇 |
原子能技术 | 17篇 |
自动化技术 | 838篇 |
出版年
2023年 | 29篇 |
2022年 | 44篇 |
2021年 | 62篇 |
2020年 | 53篇 |
2019年 | 75篇 |
2018年 | 91篇 |
2017年 | 88篇 |
2016年 | 111篇 |
2015年 | 72篇 |
2014年 | 141篇 |
2013年 | 304篇 |
2012年 | 188篇 |
2011年 | 288篇 |
2010年 | 209篇 |
2009年 | 209篇 |
2008年 | 214篇 |
2007年 | 223篇 |
2006年 | 171篇 |
2005年 | 169篇 |
2004年 | 123篇 |
2003年 | 103篇 |
2002年 | 111篇 |
2001年 | 63篇 |
2000年 | 78篇 |
1999年 | 78篇 |
1998年 | 68篇 |
1997年 | 71篇 |
1996年 | 81篇 |
1995年 | 52篇 |
1994年 | 48篇 |
1993年 | 45篇 |
1992年 | 47篇 |
1991年 | 33篇 |
1990年 | 32篇 |
1989年 | 38篇 |
1988年 | 29篇 |
1987年 | 36篇 |
1986年 | 34篇 |
1985年 | 36篇 |
1984年 | 50篇 |
1983年 | 41篇 |
1982年 | 38篇 |
1981年 | 32篇 |
1980年 | 32篇 |
1979年 | 21篇 |
1978年 | 26篇 |
1977年 | 21篇 |
1976年 | 26篇 |
1975年 | 25篇 |
1973年 | 13篇 |
排序方式: 共有4315条查询结果,搜索用时 15 毫秒
31.
Lowe Rob; Bennett Paul; Walker Ian; Milne Sarah; Bozionelos George 《Canadian Metallurgical Quarterly》2003,22(5):464
The theory of planned behavior suggests attitudes are a product of salient beliefs. This study examined whether aggregating salient beliefs was plausible within a more biologically centered information-processing environment. A neural network was used to examine associations among beliefs relating to exercise intention. Data on intentions and behavioral, normative, and control beliefs from 114 respondents were used to train (by error backpropagation) a neural network to associate beliefs with intention. The R2 between the network's estimated and self-reported intention was .66. The network's representation comprised 6 belief profiles associated with high, moderate, or low behavioral intention. The neural network accommodated complex relationships among beliefs and belief-intention associations and indicated how high-level constructs such as attitudes may be viewed as the best fit (compromise state) between aroused beliefs. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
32.
Ian McKeown 《Coloration Technology》1994,110(4):136-137
Over the last few years, Polaroid has been actively trying to reduce the amount of waste produced at its sites. In this article, Ian McKeown looks at the measures taken at the UK site in Scotland to achieve this aim. 相似文献
33.
This paper describes the application of Fault Tree Analysis to the design phase of a robot manipulator for hazardous waste retrieval. The robot is to be deployed in single-shell under-ground storage tanks at the US Department of Energy (DOE) site in Hanford, Washington. These tanks contain a variety of highly radioactive waste types, necessitating extremely safe and reliable manipulator operation. Based on preliminary design drawings of this long-reach manipulator, fault trees were constructed for several critical failure scenarios. Analysis of the trees revealed a number of ways to improve the safety and reliability of the manipulator design. This paper presents a summary of the fault tree analysis, with a discussion of the applicability of qualitative and quantitative fault tree methods to hazardous waste robotics. 相似文献
34.
Research has continued in the field sidechain liquid crystal polymers over recent years, but it is becoming clearer that this research is being directed away from the traditional technology areas of electro-optic devices and researchers are developing new and exciting applications for this novel state of matter. 相似文献
35.
Salvatore A. Bruno Donald K. Swanson Ian Burn 《Journal of the American Ceramic Society》1993,76(5):1233-1241
Advantages of chemically prepared powders for electronic ceramics have been demonstrated for a number of multilayer capacitor (MLC) dielectrics. A cost-efficient precipitation process was developed to produce undoped or doped crystalline barium titanate powder with a narrow particle size distribution close to 0.5 μm. More complex compositions, e.g., barium-neodymium titanate, were amorphous as precipitated but could be crystallized by calcination below 1000°C. Additional compositional modifications, to adjust electrical properties or to lower sintering temperature, were accomplished by doping the surface of the powder particles using a solution coating process. Exceptional fired densities and electrical performance were obtained. 相似文献
36.
GJ Wetscher G Perdikis DH Kretchmar RG Stinson D Bagchi EJ Redmond TE Adrian RA Hinder 《Canadian Metallurgical Quarterly》1995,40(6):1297-1305
Free radical-mediated esophagitis was studied during duodenogastroesophageal reflux (mixed reflux) or acid reflux in rats. The influence of reflux on esophageal glutathione levels was also examined. Mixed reflux caused more gross mucosal injury than acid reflux. Gross mucosal injury occurred in the mid-esophagus. Total glutathione (GSH) in the esophageal mucosa of control rats was highest in the distal esophagus. The time course of esophageal GSH in rats treated by mixed reflux showed a significant decrease 4 hr after initiation of reflux, followed by a significant increase from the 12th hour on. Mucosal GSH was increased in both reflux groups after 24 hr but significantly more so in the mixed than in the acid reflux group. The free radical scavenger superoxide dismutase (SOD) prevented esophagitis and was associated with decreased GSH levels. GSH depletion by buthionine sulfoximine (BSO) prevented esophagitis and stimulated SOD production in the esophageal mucosa. It is concluded that gastroesophageal reflux is associated with oxidative stress in the esophageal mucosa. The lower GSH levels in the mid-esophagus may predispose to damage in this area. Duodenogastroesophageal reflux causes more damage than pure acid reflux. Oxidative stress leads to GSH depletion of the esophageal mucosa in the first few hours following damage but then stimulates GSH production. GSH depletion by BSO does not worsen esophagitis since it increases the esophageal SOD concentration. 相似文献
37.
38.
Chen Jiaoyan Hu Pan Jimenez-Ruiz Ernesto Holter Ole Magnus Antonyrajah Denvar Horrocks Ian 《Machine Learning》2021,110(7):1813-1845
Machine Learning - Semantic embedding of knowledge graphs has been widely studied and used for prediction and statistical analysis tasks across various domains such as Natural Language Processing... 相似文献
39.
Bian Jia-Wang Zhan Huangying Wang Naiyan Li Zhichao Zhang Le Shen Chunhua Cheng Ming-Ming Reid Ian 《International Journal of Computer Vision》2021,129(9):2548-2564
International Journal of Computer Vision - We propose a monocular depth estimation method SC-Depth, which requires only unlabelled videos for training and enables the scale-consistent... 相似文献
40.