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   1493260篇
  免费   27575篇
  国内免费   7102篇
电工技术   34540篇
综合类   6419篇
化学工业   270807篇
金属工艺   64855篇
机械仪表   42879篇
建筑科学   45906篇
矿业工程   11513篇
能源动力   50263篇
轻工业   111451篇
水利工程   15102篇
石油天然气   37892篇
武器工业   144篇
无线电   197017篇
一般工业技术   283836篇
冶金工业   152291篇
原子能技术   34054篇
自动化技术   168968篇
  2021年   15613篇
  2020年   11880篇
  2019年   14645篇
  2018年   16150篇
  2017年   15634篇
  2016年   21457篇
  2015年   17349篇
  2014年   28646篇
  2013年   87765篇
  2012年   35210篇
  2011年   47885篇
  2010年   42823篇
  2009年   51305篇
  2008年   44609篇
  2007年   42034篇
  2006年   44315篇
  2005年   39499篇
  2004年   41406篇
  2003年   41296篇
  2002年   40264篇
  2001年   36897篇
  2000年   35399篇
  1999年   34314篇
  1998年   41096篇
  1997年   36820篇
  1996年   33856篇
  1995年   29909篇
  1994年   28121篇
  1993年   27927篇
  1992年   26049篇
  1991年   23144篇
  1990年   23523篇
  1989年   22553篇
  1988年   21117篇
  1987年   19427篇
  1986年   18783篇
  1985年   22136篇
  1984年   22370篇
  1983年   20281篇
  1982年   19217篇
  1981年   19297篇
  1980年   17914篇
  1979年   18544篇
  1978年   17759篇
  1977年   17416篇
  1976年   18244篇
  1975年   16039篇
  1974年   15565篇
  1973年   15640篇
  1972年   13136篇
排序方式: 共有10000条查询结果,搜索用时 20 毫秒
111.
Cybernetics and Systems Analysis - The authors propose a method for solving the problem of approach of controlled objects in dynamic game problems with a terminal payoff function. The method is...  相似文献   
112.
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   
113.
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   
114.
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   
115.
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   
116.
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   
117.
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   
118.
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   
119.
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   
120.

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   
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