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   309231篇
  免费   5397篇
  国内免费   1327篇
电工技术   5014篇
综合类   548篇
化学工业   46016篇
金属工艺   11666篇
机械仪表   9024篇
建筑科学   7456篇
矿业工程   1637篇
能源动力   7615篇
轻工业   26629篇
水利工程   3297篇
石油天然气   5905篇
武器工业   47篇
无线电   35413篇
一般工业技术   62245篇
冶金工业   58269篇
原子能技术   7606篇
自动化技术   27568篇
  2021年   2867篇
  2020年   2247篇
  2019年   2615篇
  2018年   4839篇
  2017年   4909篇
  2016年   5179篇
  2015年   3384篇
  2014年   5505篇
  2013年   14207篇
  2012年   8990篇
  2011年   11511篇
  2010年   8955篇
  2009年   9992篇
  2008年   10587篇
  2007年   10401篇
  2006年   8764篇
  2005年   8056篇
  2004年   7949篇
  2003年   7634篇
  2002年   7284篇
  2001年   7184篇
  2000年   6812篇
  1999年   7197篇
  1998年   18511篇
  1997年   12935篇
  1996年   9825篇
  1995年   7367篇
  1994年   6462篇
  1993年   6493篇
  1992年   4554篇
  1991年   4357篇
  1990年   4255篇
  1989年   4216篇
  1988年   3908篇
  1987年   3514篇
  1986年   3523篇
  1985年   3903篇
  1984年   3610篇
  1983年   3321篇
  1982年   3149篇
  1981年   3189篇
  1980年   3153篇
  1979年   2931篇
  1978年   2964篇
  1977年   3298篇
  1976年   4420篇
  1975年   2485篇
  1974年   2439篇
  1973年   2458篇
  1972年   2054篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
101.
102.
103.
104.
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   
105.
Wireless Personal Communications - Cloud computing is a growing technology where lot of heterogeneous resources are available and large amount of requests are submitted by the customers...  相似文献   
106.
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   
107.
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   
108.
Russian Engineering Research - The machining precision in grinding a flexible shaft by sharp and blunt wheels is compared for a CNC system with a specified cycle of radial supply velocities. To...  相似文献   
109.
110.
International Journal of Computer Vision - Anticipating future situations from streaming sensor data is a key perception challenge for mobile robotics and automated vehicles. We address the problem...  相似文献   
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