首页 | 官方网站   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   1529198篇
  免费   27820篇
  国内免费   6945篇
工业技术   1563963篇
  2021年   14700篇
  2020年   11957篇
  2019年   14693篇
  2018年   17167篇
  2017年   16498篇
  2016年   22065篇
  2015年   17550篇
  2014年   28797篇
  2013年   88104篇
  2012年   37072篇
  2011年   50654篇
  2010年   43943篇
  2009年   51853篇
  2008年   46928篇
  2007年   44305篇
  2006年   45879篇
  2005年   40879篇
  2004年   42779篇
  2003年   42516篇
  2002年   39131篇
  2001年   36082篇
  2000年   33660篇
  1999年   33805篇
  1998年   52263篇
  1997年   42989篇
  1996年   36574篇
  1995年   32360篇
  1994年   29993篇
  1993年   29942篇
  1992年   26155篇
  1991年   23338篇
  1990年   23697篇
  1989年   22637篇
  1988年   21161篇
  1987年   19481篇
  1986年   18874篇
  1985年   22184篇
  1984年   22160篇
  1983年   20093篇
  1982年   19136篇
  1981年   19283篇
  1980年   17918篇
  1979年   18347篇
  1978年   17663篇
  1977年   17819篇
  1976年   19453篇
  1975年   15841篇
  1974年   15342篇
  1973年   15462篇
  1972年   12997篇
排序方式: 共有10000条查询结果,搜索用时 77 毫秒
91.
Journal of Materials Science: Materials in Electronics - Nonlinear optical organometallic single crystal of manganese mercury thiocyanate (MMTC) has been grown by SR method in aqueous solution. The...  相似文献   
92.
Journal of Materials Science: Materials in Electronics - Sn–Zn–Cu is one of the most popular soldering alloys, especially when it has been doped with Bi, which has proved very...  相似文献   
93.

ResearchGate has emerged as a popular professional network for scientists and researchers in a very short span. Similar to Google Scholar, the ResearchGate indexing uses an automatic crawling algorithm that extracts bibliographic data, citations, and other information about scholarly articles from various sources. However, it has been observed that the two platforms often show different publication and citation data for the same institutions, journals, and authors. While several previous studies analysed different aspects of ResearchGate and Google Scholar, the quantum of differences in publications, citations, and metrics between the two and the probable reasons for the same are not explored much. This article, therefore, attempts to bridge this research gap by analysing and measuring the differences in publications, citations, and different metrics of the two platforms for a large data set of highly cited authors. The results indicate that there are significantly high differences in publications and citations for the same authors captured by the two platforms, with Google Scholar having higher counts for a vast majority of the cases. The different metrics computed by the two platforms also differ in their values, showing different degrees of correlation. The coverage policy, indexing errors, author attribution mechanism, and strategy to deal with predatory publishing are found to be the main probable reasons for the differences in the two platforms.

  相似文献   
94.
Filtration Waves     
Journal of Engineering Physics and Thermophysics - Equations and relations have been obtained for describing one-dimensional filtration waves in a homogeneous isotropic porous medium in plane,...  相似文献   
95.
Journal of Engineering Physics and Thermophysics - A laminar boundary layer in a gas flow near a disk rotating at a constant angular velocity under the conditions of a significant radial...  相似文献   
96.
Journal of Engineering Physics and Thermophysics - An overview of the development of mathematical models used to describe the relationship between the parameters of the state of real gases is...  相似文献   
97.
Kulemin  V. V.  Martynov  K. V.  Krasavina  E. P.  Rumer  I. A.  Kulyukhin  S. A. 《Radiochemistry》2022,64(2):158-163
Radiochemistry - The distribution of uranium between different phases of cast stone matrices fabricated by fusion of basalt and uranium-bearing SiO2-based collectors was investigated. It was found...  相似文献   
98.
Savruk  M. P.  Kravets  V. S.  Chornenkyi  A. B. 《Materials Science》2022,57(4):492-501
Materials Science - We develop an analytic-numerical algorithm for the determination of the optimal shape of smooth holes (with minimum stress concentration) in quasiorthotropic plates subjected to...  相似文献   
99.
Journal of Engineering Physics and Thermophysics - The possibility of intensifying the drying of materials by noncontact ultrasonic action at a frequency of 22 kHz at sound pressure levels up to...  相似文献   
100.
Yakunin  S. A. 《Radiochemistry》2022,64(4):482-490
Radiochemistry - As applied to the radioactive waste vitrification technology, published data on the behavior of cesium and its release into the gas phase are reviewed. The volatility of cesium...  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-23

京公网安备 11010802026262号