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   1476486篇
  免费   27223篇
  国内免费   6949篇
电工技术   33979篇
综合类   6362篇
化学工业   268589篇
金属工艺   63484篇
机械仪表   41186篇
建筑科学   45887篇
矿业工程   11294篇
能源动力   50101篇
轻工业   110606篇
水利工程   14955篇
石油天然气   37243篇
武器工业   131篇
无线电   194902篇
一般工业技术   278944篇
冶金工业   151537篇
原子能技术   33722篇
自动化技术   167736篇
  2021年   15424篇
  2020年   11769篇
  2019年   14567篇
  2018年   14447篇
  2017年   13646篇
  2016年   20725篇
  2015年   17181篇
  2014年   28577篇
  2013年   87554篇
  2012年   34710篇
  2011年   46379篇
  2010年   41349篇
  2009年   49880篇
  2008年   43569篇
  2007年   40559篇
  2006年   44358篇
  2005年   38657篇
  2004年   41040篇
  2003年   41011篇
  2002年   40114篇
  2001年   37086篇
  2000年   35497篇
  1999年   34374篇
  1998年   42253篇
  1997年   37369篇
  1996年   33975篇
  1995年   29913篇
  1994年   28161篇
  1993年   28000篇
  1992年   25890篇
  1991年   22967篇
  1990年   23305篇
  1989年   22305篇
  1988年   20893篇
  1987年   19126篇
  1986年   18518篇
  1985年   21884篇
  1984年   22215篇
  1983年   20207篇
  1982年   19193篇
  1981年   19271篇
  1980年   17858篇
  1979年   18468篇
  1978年   17658篇
  1977年   17175篇
  1976年   17605篇
  1975年   15946篇
  1974年   15470篇
  1973年   15562篇
  1972年   13004篇
排序方式: 共有10000条查询结果,搜索用时 31 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