首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   110870篇
  免费   16929篇
  国内免费   76篇
电工技术   1256篇
综合类   68篇
化学工业   30606篇
金属工艺   1740篇
机械仪表   2103篇
建筑科学   4000篇
矿业工程   143篇
能源动力   2584篇
轻工业   16818篇
水利工程   942篇
石油天然气   355篇
武器工业   5篇
无线电   10136篇
一般工业技术   23653篇
冶金工业   18057篇
原子能技术   388篇
自动化技术   15021篇
  2023年   600篇
  2022年   857篇
  2021年   2145篇
  2020年   2803篇
  2019年   4604篇
  2018年   5450篇
  2017年   5577篇
  2016年   6248篇
  2015年   5530篇
  2014年   6128篇
  2013年   9809篇
  2012年   6791篇
  2011年   6501篇
  2010年   5755篇
  2009年   5404篇
  2008年   5130篇
  2007年   4683篇
  2006年   3803篇
  2005年   3232篇
  2004年   3015篇
  2003年   2791篇
  2002年   2619篇
  2001年   2064篇
  2000年   2000篇
  1999年   1587篇
  1998年   5509篇
  1997年   3543篇
  1996年   2308篇
  1995年   1402篇
  1994年   1144篇
  1993年   1179篇
  1992年   439篇
  1991年   458篇
  1990年   409篇
  1989年   388篇
  1988年   360篇
  1987年   317篇
  1986年   325篇
  1985年   368篇
  1984年   315篇
  1983年   247篇
  1982年   311篇
  1981年   329篇
  1980年   318篇
  1979年   208篇
  1978年   209篇
  1977年   487篇
  1976年   1012篇
  1975年   146篇
  1973年   154篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
91.
92.
93.
94.
95.
96.
Csáji  Balázs Cs.  Kis  Krisztián B. 《Machine Learning》2019,108(8-9):1677-1699
Machine Learning - We propose a data-driven approach to quantify the uncertainty of models constructed by kernel methods. Our approach minimizes the needed distributional assumptions, hence,...  相似文献   
97.
Water Resources Management - This paper aims to evaluate the possibility of using non-utilized hydraulic energy in urban water distribution systems. For this purpose, the viability and possible...  相似文献   
98.
For decades now, Douglas Crimp’s landmark 1980 essay ‘The Photographic Activity of Postmodernism’ has shaped our understanding of modernism’s aftermath, at least as it unfolded in North America and Western Europe. Less remembered, however, is the degree to which the procedures of disjunction, copying, appropriation, and outright theft that he highlighted were epitomised not just by contemporary photography, but by photomontage in particular. This article recovers the debates that led critics such as Crimp, Abigail Solomon-Godeau, Christopher Phillips, Benjamin Buchloh and others to turn to photomontage as one of their principal objects of concern in what became known as the postmodern critique of photography. Why was montage tasked to perform this critical function, particularly by people around the journal October who had not otherwise devoted the balance of their writing to photography’s history? The article suggests that these men and women, along with the contemporary artists they foregrounded, manifested what Mary Anne Doane has called a ‘desire for signification’, a reaction in the late 1970s against the mute theatricality of minimalist and conceptual art. Photomontage reintroduced representation to contemporary art and to the canon of art history. But unlike the reemerging illusionism in painting that also manifested this desire, montage guarded against an uncomplicated realism by highlighting and critiquing operations of representation in a manner that painting no longer could.  相似文献   
99.
In the quest for new antibacterial agents, a series of novel long- and medium-chain mono- and disubstituted β-lactones was developed. Their activity against three pathogenic mycobacteria—M. abscessus, M. marinum, and M. tuberculosis—was assessed by the resazurin microtiter assay (REMA). Among the 16 β-lactones synthesized, only 3-hexadecyloxetan-2-one (VM005) exhibited promising activity against M. abscessus, whereas most of the β-lactones showed interesting activities against M. marinum, similar to that of the classical antibiotic, isoniazid. Regarding M. tuberculosis, six compounds were found to be active against this mycobacterium, with β-lactone VM008 [trans-(Z)-3-(hexadec-7-en-1-yl)-4-propyloxetan-2-one] being the best growth inhibitor. The promising antibacterial activities of the best compounds in this series suggest that these molecules may serve as leads for the development of much more efficient antimycobacterial agents.  相似文献   
100.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号