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   1493758篇
  免费   27329篇
  国内免费   6896篇
电工技术   34193篇
综合类   6360篇
化学工业   268317篇
金属工艺   64054篇
机械仪表   41913篇
建筑科学   46070篇
矿业工程   11362篇
能源动力   50322篇
轻工业   112910篇
水利工程   14862篇
石油天然气   37512篇
武器工业   129篇
无线电   195772篇
一般工业技术   283137篇
冶金工业   158041篇
原子能技术   33897篇
自动化技术   169132篇
  2021年   15449篇
  2020年   11812篇
  2019年   14597篇
  2018年   15229篇
  2017年   14425篇
  2016年   21040篇
  2015年   17254篇
  2014年   28643篇
  2013年   87828篇
  2012年   35135篇
  2011年   47174篇
  2010年   41929篇
  2009年   50501篇
  2008年   44209篇
  2007年   41342篇
  2006年   44581篇
  2005年   39020篇
  2004年   41390篇
  2003年   41289篇
  2002年   40486篇
  2001年   37183篇
  2000年   35694篇
  1999年   34587篇
  1998年   42751篇
  1997年   37947篇
  1996年   34673篇
  1995年   30410篇
  1994年   28631篇
  1993年   28395篇
  1992年   26238篇
  1991年   23325篇
  1990年   23655篇
  1989年   22734篇
  1988年   21307篇
  1987年   19508篇
  1986年   18955篇
  1985年   22358篇
  1984年   22486篇
  1983年   20492篇
  1982年   19334篇
  1981年   19443篇
  1980年   18030篇
  1979年   18662篇
  1978年   17812篇
  1977年   17629篇
  1976年   18667篇
  1975年   16071篇
  1974年   15616篇
  1973年   15670篇
  1972年   13175篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
At present, the development and implementation of digital transformation are the keys to promoting high-quality industry development. The new digital fabrication method of robotic 3D printing is a research area being studied by many to tackle the issue of the declining productivity of traditional construction methods. Although many studies have been done, most of the current 3D printing projects are facing limitations in terms of scale. In order to bridge the gap, this article proposed a mass customization 3D printing framework system for large-scale projects. This article discusses how mass customization is made possible through the joint operation of the FUROBOT software and 3D printing hardware. By taking the east gate of Nanjing Happy Valley Plaza as a case study, the article demonstrates and studies the feasibility of the large-scale mass customization 3D printing framework system.  相似文献   
112.
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   
113.
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   
114.
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   
115.
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   
116.
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   
117.
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   
118.
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   
119.
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   
120.
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   
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