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   3618篇
  免费   40篇
  国内免费   13篇
电工技术   18篇
综合类   12篇
化学工业   159篇
金属工艺   26篇
机械仪表   23篇
建筑科学   16篇
矿业工程   1篇
能源动力   19篇
轻工业   183篇
水利工程   7篇
石油天然气   5篇
无线电   48篇
一般工业技术   87篇
冶金工业   3007篇
原子能技术   2篇
自动化技术   58篇
  2024年   3篇
  2023年   3篇
  2022年   31篇
  2021年   32篇
  2020年   18篇
  2019年   24篇
  2018年   31篇
  2017年   15篇
  2016年   12篇
  2015年   20篇
  2014年   26篇
  2013年   81篇
  2012年   42篇
  2011年   44篇
  2010年   33篇
  2009年   42篇
  2008年   30篇
  2007年   22篇
  2006年   18篇
  2005年   19篇
  2004年   15篇
  2003年   16篇
  2002年   5篇
  2001年   5篇
  2000年   4篇
  1999年   99篇
  1998年   946篇
  1997年   571篇
  1996年   357篇
  1995年   176篇
  1994年   147篇
  1993年   207篇
  1992年   28篇
  1991年   14篇
  1990年   22篇
  1989年   17篇
  1988年   23篇
  1987年   18篇
  1986年   19篇
  1985年   21篇
  1984年   4篇
  1983年   10篇
  1982年   14篇
  1981年   20篇
  1980年   27篇
  1978年   11篇
  1977年   96篇
  1976年   210篇
  1975年   7篇
  1955年   4篇
排序方式: 共有3671条查询结果,搜索用时 457 毫秒
41.
42.
43.
To determine whether physical match between studied and tested items influences blood flow increases in the hippocampal formation associated with recognition memory, positron emission tomography (PET) was used to measure changes in regional cerebral blood flow while healthy volunteers made old/new judgements about line drawings of objects. Some objects were tested in the same size and orientation as they had appeared earlier during the study phase of the experiment; other objects were tested in a different size or orientation than when they were studied. Blood flow increases in the vicinity of the hippocampal formation were observed in the same object condition compared with the size change and the orientation change conditions, even though recognition accuracy was affected significantly only by orientation change. Results add to previous findings suggesting that physical similarity between studied items and test cues may contribute to hippocampal activation during episodic retrieval.  相似文献   
44.
45.
Medical networks offer discounted fees, control of the workers' compensation case, quality monitoring, and managed care services. As channeling of workers' compensation cases to networks increases, credentialed physicians will benefit.  相似文献   
46.
LA Mastaj  DJ Tartakow  AJ Borislow  MS Fogel 《Canadian Metallurgical Quarterly》1994,15(1):74, 76, 78-80, passim; quiz 86
Infections present a significant hazard in the orthodontic office because they can be transmitted by blood or saliva through direct or indirect contact, droplets, aerosols, or contaminated instruments and equipment. Because the incidence of certain microbial cross-infections in the dental environment has not been well documented, orthodontic personnel may not take the problem of cross-infection as seriously as they should, and they may transmit or contract more infections than they realize. The use of effective infection-control procedures in the orthodontic office and laboratory will prevent cross-contamination that may extend to the orthodontist, office staff, assistants, and patients. The goal of this article is to present infection control in a simple, yet comprehensive, manner, and to encourage all orthodontic practitioners to implement essential infection-control procedures in their practices.  相似文献   
47.
48.
49.
50.
Retrobulbar hematoma is a rare complication of blunt periorbital trauma with the potential disastrous consequence of visual impairment and blindness. The preoperative assessment, diagnostic symptoms and signs, as well as the treatment of this condition are reviewed. The patients presented as well as a review of the literature confirm that although retrobulbar hematoma is a rare complication of blunt periorbital trauma, irreversible visual sequelae can be prevented by prompt diagnosis and immediate surgical and pharmacological therapy.  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