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   1541258篇
  免费   28483篇
  国内免费   7830篇
电工技术   35520篇
技术理论   5篇
综合类   7402篇
化学工业   272280篇
金属工艺   65310篇
机械仪表   43549篇
建筑科学   47344篇
矿业工程   11851篇
能源动力   50439篇
轻工业   117794篇
水利工程   15565篇
石油天然气   38451篇
武器工业   370篇
无线电   198288篇
一般工业技术   288078篇
冶金工业   180367篇
原子能技术   34042篇
自动化技术   170916篇
  2021年   15992篇
  2020年   12103篇
  2019年   14843篇
  2018年   15975篇
  2017年   15373篇
  2016年   21580篇
  2015年   17890篇
  2014年   29188篇
  2013年   88702篇
  2012年   37038篇
  2011年   49906篇
  2010年   43870篇
  2009年   52061篇
  2008年   46528篇
  2007年   44012篇
  2006年   46285篇
  2005年   40706篇
  2004年   42265篇
  2003年   41952篇
  2002年   41090篇
  2001年   38232篇
  2000年   36544篇
  1999年   35886篇
  1998年   50809篇
  1997年   42612篇
  1996年   37474篇
  1995年   31884篇
  1994年   29749篇
  1993年   29665篇
  1992年   26471篇
  1991年   23560篇
  1990年   23888篇
  1989年   22936篇
  1988年   21462篇
  1987年   19660篇
  1986年   19075篇
  1985年   22390篇
  1984年   22553篇
  1983年   20438篇
  1982年   19387篇
  1981年   19538篇
  1980年   18065篇
  1979年   18647篇
  1978年   17890篇
  1977年   17719篇
  1976年   19063篇
  1975年   16086篇
  1974年   15611篇
  1973年   15650篇
  1972年   13150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