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   1607651篇
  免费   32965篇
  国内免费   10119篇
电工技术   38959篇
技术理论   7篇
综合类   10811篇
化学工业   279904篇
金属工艺   68336篇
机械仪表   47634篇
建筑科学   51500篇
矿业工程   13187篇
能源动力   51644篇
轻工业   125339篇
水利工程   16767篇
石油天然气   40633篇
武器工业   831篇
无线电   204128篇
一般工业技术   297912篇
冶金工业   189373篇
原子能技术   34997篇
自动化技术   178773篇
  2021年   18145篇
  2020年   13781篇
  2019年   16144篇
  2018年   18235篇
  2017年   17803篇
  2016年   23494篇
  2015年   19838篇
  2014年   31559篇
  2013年   91370篇
  2012年   40946篇
  2011年   54748篇
  2010年   47712篇
  2009年   55445篇
  2008年   50518篇
  2007年   48165篇
  2006年   49405篇
  2005年   43790篇
  2004年   44361篇
  2003年   43861篇
  2002年   42884篇
  2001年   39667篇
  2000年   37860篇
  1999年   37003篇
  1998年   52522篇
  1997年   44128篇
  1996年   38660篇
  1995年   32675篇
  1994年   30465篇
  1993年   30189篇
  1992年   26890篇
  1991年   23939篇
  1990年   24214篇
  1989年   23257篇
  1988年   21876篇
  1987年   20047篇
  1986年   19378篇
  1985年   22687篇
  1984年   22658篇
  1983年   20586篇
  1982年   19455篇
  1981年   19628篇
  1980年   18266篇
  1979年   18795篇
  1978年   17985篇
  1977年   18126篇
  1976年   19953篇
  1975年   16231篇
  1974年   15691篇
  1973年   15783篇
  1972年   13266篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
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   
122.
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   
123.
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   
124.
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   
125.
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   
126.
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   
127.
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   
128.
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   
129.
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   
130.

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