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   1514562篇
  免费   29193篇
  国内免费   7122篇
电工技术   34451篇
综合类   6431篇
化学工业   276686篇
金属工艺   64876篇
机械仪表   43544篇
建筑科学   46685篇
矿业工程   11338篇
能源动力   51605篇
轻工业   113709篇
水利工程   15124篇
石油天然气   37328篇
武器工业   131篇
无线电   200593篇
一般工业技术   286340篇
冶金工业   155603篇
原子能技术   34105篇
自动化技术   172328篇
  2021年   16656篇
  2020年   12561篇
  2019年   15388篇
  2018年   15556篇
  2017年   14733篇
  2016年   22046篇
  2015年   18157篇
  2014年   30115篇
  2013年   89957篇
  2012年   37275篇
  2011年   49544篇
  2010年   43586篇
  2009年   52103篇
  2008年   45672篇
  2007年   42202篇
  2006年   45741篇
  2005年   39813篇
  2004年   42023篇
  2003年   41865篇
  2002年   41043篇
  2001年   37802篇
  2000年   36135篇
  1999年   35061篇
  1998年   43771篇
  1997年   38326篇
  1996年   34707篇
  1995年   30429篇
  1994年   28547篇
  1993年   28328篇
  1992年   26055篇
  1991年   23162篇
  1990年   23422篇
  1989年   22460篇
  1988年   21007篇
  1987年   19242篇
  1986年   18631篇
  1985年   21968篇
  1984年   22261篇
  1983年   20247篇
  1982年   19234篇
  1981年   19311篇
  1980年   17889篇
  1979年   18487篇
  1978年   17675篇
  1977年   17207篇
  1976年   17685篇
  1975年   15956篇
  1974年   15479篇
  1973年   15568篇
  1972年   13010篇
排序方式: 共有10000条查询结果,搜索用时 31 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