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   2087652篇
  免费   89807篇
  国内免费   50160篇
电工技术   81300篇
综合类   64325篇
化学工业   335019篇
金属工艺   100697篇
机械仪表   81211篇
建筑科学   87877篇
矿业工程   34516篇
能源动力   63154篇
轻工业   181831篇
水利工程   34216篇
石油天然气   54968篇
武器工业   8877篇
无线电   251226篇
一般工业技术   336667篇
冶金工业   219145篇
原子能技术   42177篇
自动化技术   250413篇
  2022年   30577篇
  2021年   41492篇
  2020年   30778篇
  2019年   27491篇
  2018年   29152篇
  2017年   30936篇
  2016年   35976篇
  2015年   40647篇
  2014年   58180篇
  2013年   121999篇
  2012年   81068篇
  2011年   95630篇
  2010年   86486篇
  2009年   92153篇
  2008年   89983篇
  2007年   86588篇
  2006年   82485篇
  2005年   70231篇
  2004年   64165篇
  2003年   56657篇
  2002年   54607篇
  2001年   50973篇
  2000年   46477篇
  1999年   40268篇
  1998年   57258篇
  1997年   46728篇
  1996年   40283篇
  1995年   33920篇
  1994年   31407篇
  1993年   31060篇
  1992年   27209篇
  1991年   24309篇
  1990年   24492篇
  1989年   23569篇
  1988年   22088篇
  1987年   20177篇
  1986年   19677篇
  1985年   23049篇
  1984年   22986篇
  1983年   20910篇
  1982年   19660篇
  1981年   19806篇
  1980年   18505篇
  1979年   19024篇
  1978年   18074篇
  1977年   18490篇
  1976年   20530篇
  1975年   16250篇
  1974年   15742篇
  1973年   15844篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
151.
Journal of Computer and Systems Sciences International - The solution of the problem of determining the trajectory control of the observation process of a mobile digital direction finder in the...  相似文献   
152.
Vieira  Elizabeth S. 《Scientometrics》2022,127(5):2747-2772

It is widely recognised that science in Africa will benefit from international research collaboration (IRC), and therefore studies have been done on IRC in Africa (hereafter: Africa-related IRC research). However, there is no information on the development of Africa-related IRC research, the geographical location of the scientists interested in the topic, the visibility of the literature and the themes researched. This information makes it possible to understand relevant aspects in the context of IRC in Africa, which are useful for identifying IRC strengths, weaknesses and opportunities. It also allows paving the way for future research on this topic. Using discipline–specific terms, bibliometric, and thematic analysis, I collected the literature on Africa-related IRC research indexed in the Web of Science Core Collection (WoS). The results showed that the number of publications on the topic has increased, few African countries have researched the topic, a third of the publications were written exclusively by African scientists, and the topic has high visibility. The panoply of publications revealed that patterns, driving factors, effects, networks, asymmetries, and policies concerning IRC were the main themes researched.

  相似文献   
153.
Marrone  Mauricio  Lemke  Sascha  Kolbe  Lutz M. 《Scientometrics》2022,127(7):3857-3878
Scientometrics - Computer-assisted methods and tools can help researchers automate the coding process of literature reviews and accelerate the literature review process. However, existing...  相似文献   
154.
Chemical and Petroleum Engineering - The hydrodynamics of oxidation towers used for bitumen production were studied using a model tower having transparent walls. Experiments were carried out in two...  相似文献   
155.
Journal of Engineering Physics and Thermophysics - A numerical investigation has been made into the interaction of slender (5–20 calibers) steel cylinder strikers with orthotropic compost...  相似文献   
156.
Journal of Engineering Physics and Thermophysics - Results of investigation into the influence of a corrosion process on thermotechnical characteristics of heat pipes of low-temperature range are...  相似文献   
157.
Deshmukh  P.  Sar  S. K.  Smječanin  N.  Nuhanović  M.  Lalwani  R. 《Radiochemistry》2022,64(4):532-542
Radiochemistry - Magnetically modified waste bark of the Aegle marmelos tree was prepared by using green synthesis method and was used in a batch system for U(VI) removal from aqueous solution. The...  相似文献   
158.
Kamar  M. S.  Shalan  A. S.  Youssef  W. M.  Hussein  A. E. M.  Khawassek  Y. M.  Taha  M. H. 《Radiochemistry》2022,64(2):244-256
Radiochemistry - Ferrugination, sericitization, desulfitization, chloritization, and kaolinitization of hydrothermal origin are the main wall rock alterations occurring within the NNW shear zones...  相似文献   
159.

Modern metrics for evaluating agreement coefficients between the experimental results and expert opinion are compared, and the possibility of using these metrics in experimental research in automatic text processing by machine learning methods is assessed. The choice of Cohen’s kappa coefficient as a measure of expert opinion agreement in the NLP and Text Mining problems is justified. An example of using Cohen’s kappa coefficient for evaluating the level of agreement between the opinion of an expert and the results of ML classification and the measure of agreement of expert opinions in the alignment of sentences of the Kazakh-Russian parallel corpus is given. Based on this analysis, it is proved that Cohen’s kappa coefficient is one of the best statistical methods for determining the level of agreement in experimental studies due to its ease of use, computing simplicity, and high accuracy of the results.

  相似文献   
160.
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