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   1498170篇
  免费   27743篇
  国内免费   6921篇
工业技术   1532834篇
  2021年   14714篇
  2020年   11901篇
  2019年   14694篇
  2018年   14971篇
  2017年   14160篇
  2016年   21211篇
  2015年   17455篇
  2014年   28952篇
  2013年   88298篇
  2012年   36579篇
  2011年   49031篇
  2010年   42529篇
  2009年   50686篇
  2008年   45843篇
  2007年   43115篇
  2006年   46043篇
  2005年   40229篇
  2004年   42722篇
  2003年   42494篇
  2002年   39368篇
  2001年   36035篇
  2000年   33698篇
  1999年   33146篇
  1998年   44687篇
  1997年   38597篇
  1996年   33994篇
  1995年   31070篇
  1994年   29122篇
  1993年   28693篇
  1992年   26057篇
  1991年   23222篇
  1990年   23530篇
  1989年   22477篇
  1988年   20997篇
  1987年   19312篇
  1986年   18860篇
  1985年   22259篇
  1984年   22374篇
  1983年   20233篇
  1982年   19144篇
  1981年   19193篇
  1980年   17833篇
  1979年   18484篇
  1978年   17684篇
  1977年   17770篇
  1976年   19328篇
  1975年   15893篇
  1974年   15454篇
  1973年   15535篇
  1972年   13093篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
91.
Journal of Materials Science: Materials in Electronics - Limited light absorption and acute charge recombination on the surface of ZnO nanostructure-based photoelectrodes are the basic challenges...  相似文献   
92.
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   
93.
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   
94.

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   
95.
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   
96.
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   
97.
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   
98.
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   
99.
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   
100.
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   
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