全文获取类型
收费全文 | 4837篇 |
免费 | 354篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 45篇 |
综合类 | 5篇 |
化学工业 | 1022篇 |
金属工艺 | 94篇 |
机械仪表 | 123篇 |
建筑科学 | 195篇 |
矿业工程 | 14篇 |
能源动力 | 144篇 |
轻工业 | 573篇 |
水利工程 | 43篇 |
石油天然气 | 11篇 |
无线电 | 429篇 |
一般工业技术 | 1005篇 |
冶金工业 | 576篇 |
原子能技术 | 23篇 |
自动化技术 | 894篇 |
出版年
2023年 | 56篇 |
2022年 | 53篇 |
2021年 | 138篇 |
2020年 | 110篇 |
2019年 | 99篇 |
2018年 | 174篇 |
2017年 | 210篇 |
2016年 | 222篇 |
2015年 | 151篇 |
2014年 | 205篇 |
2013年 | 412篇 |
2012年 | 350篇 |
2011年 | 298篇 |
2010年 | 284篇 |
2009年 | 263篇 |
2008年 | 250篇 |
2007年 | 203篇 |
2006年 | 170篇 |
2005年 | 153篇 |
2004年 | 106篇 |
2003年 | 111篇 |
2002年 | 113篇 |
2001年 | 58篇 |
2000年 | 41篇 |
1999年 | 65篇 |
1998年 | 147篇 |
1997年 | 99篇 |
1996年 | 67篇 |
1995年 | 61篇 |
1994年 | 59篇 |
1993年 | 53篇 |
1992年 | 26篇 |
1991年 | 27篇 |
1990年 | 24篇 |
1989年 | 21篇 |
1988年 | 23篇 |
1987年 | 26篇 |
1986年 | 25篇 |
1985年 | 25篇 |
1984年 | 14篇 |
1983年 | 13篇 |
1982年 | 19篇 |
1981年 | 18篇 |
1980年 | 15篇 |
1979年 | 18篇 |
1978年 | 10篇 |
1977年 | 10篇 |
1976年 | 19篇 |
1974年 | 10篇 |
1973年 | 10篇 |
排序方式: 共有5196条查询结果,搜索用时 241 毫秒
31.
The first stages of nickel electrodeposition on amorphous carbon and polycrystalline silver substrates have been studied under galvanostatic conditions. An island growth mode is observed on the two types of substrate. For equivalent conditions the cluster density is higher on silver substrates than on carbon substrates. Dissolution of some nickel clusters is observed a short time after the onset of electrolysis on carbon substrates. This is confirmed by the evolution of the current efficiency and the evolution of the metal surface cluster density as a function of the quantity of electricity. 相似文献
32.
33.
34.
Previous studies have shown that bizarre and common images produce equivalent levels of recall in unmixed-list designs. Using unmixed lists, we tested the view that bizarre images would be less susceptible than common images to common sources of interference. In all experiments, subjects imaged a list of either bizarre or common sentences and then performed some kind of interfering task before recalling the initial list of sentences. Experiment 1 showed that bizarre images were better accessed than common images after imaging an intervening list of common sentences. Also, components of common images tended to be better recalled than those of bizarre images after imaging an intervening list of bizarre sentences. Experiments 2a and 2b showed that interfering tasks consisting of studying lists of common concrete nouns did not differentially affect memory for bizarre and common images. In Experiment 3, labeling and imaging an interfering list of common pictures produced higher recall of bizarre images. Generally, bizarre images appeared to be less susceptible than common images to interference from certain types of common encodings. Importantly, the superior recall of bizarre images was always due to greater image (sentence) access, whereas higher recall of common images was associated with greater recovery of the image (sentence) constituents. Explanation of the precise pattern of results requires consideration of the distinctive properties of bizarre images. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
35.
36.
András Nagy 《Polymer Bulletin》1985,14(3-4):259-264
Summary The Kennedy-Smith plot routinely used for the characterization of end-reactive (telechelic) polyisobutylenes has been recast to increase its accuracy and thus to increase its diagnostic value for the compositional analysis of telechelic polymers containing chromophores. A detailed error estimation is given. The plotting method and error limits are shown for representative mono-, di-, and tri-ended telechelic polyisobutylenes. 相似文献
37.
Comments on J. J. Magnavita's (see record 1993-42219-001) assertion that Freud's purported discovery of unconscious processes and psychic structures "laid the groundwork for the scientific investigation of emotional disorders and techniques for their amelioration." Freud fabricated an architectonic structure from hypothetical constructs that were developed over 150 yrs of psychophilosophical and clinical investigations of psychotherapy. The concepts popularized by Freud are often seen as increasingly antiquated or as impediments to a contemporary science of the mind. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
38.
39.
40.