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   1402597篇
  免费   26802篇
  国内免费   6825篇
电工技术   33783篇
综合类   6304篇
化学工业   264159篇
金属工艺   62662篇
机械仪表   38934篇
建筑科学   43962篇
矿业工程   11199篇
能源动力   50042篇
轻工业   99401篇
水利工程   13900篇
石油天然气   37215篇
武器工业   128篇
无线电   193070篇
一般工业技术   266655篇
冶金工业   116535篇
原子能技术   33632篇
自动化技术   164643篇
  2021年   15357篇
  2020年   11699篇
  2019年   14469篇
  2018年   13726篇
  2017年   12878篇
  2016年   20179篇
  2015年   17091篇
  2014年   28476篇
  2013年   87375篇
  2012年   32524篇
  2011年   43147篇
  2010年   40155篇
  2009年   49183篇
  2008年   40940篇
  2007年   37568篇
  2006年   42299篇
  2005年   36498篇
  2004年   39187篇
  2003年   39303篇
  2002年   38747篇
  2001年   34958篇
  2000年   33844篇
  1999年   32095篇
  1998年   29887篇
  1997年   30167篇
  1996年   29445篇
  1995年   27246篇
  1994年   26037篇
  1993年   25949篇
  1992年   25272篇
  1991年   22173篇
  1990年   22633篇
  1989年   21709篇
  1988年   20151篇
  1987年   18568篇
  1986年   17852篇
  1985年   21219篇
  1984年   21821篇
  1983年   19798篇
  1982年   18934篇
  1981年   18994篇
  1980年   17551篇
  1979年   18182篇
  1978年   17436篇
  1977年   16534篇
  1976年   16382篇
  1975年   15759篇
  1974年   15306篇
  1973年   15362篇
  1972年   12846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