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   1514747篇
  免费   28003篇
  国内免费   7045篇
工业技术   1549795篇
  2021年   14833篇
  2020年   11974篇
  2019年   14755篇
  2018年   17277篇
  2017年   16756篇
  2016年   22117篇
  2015年   17597篇
  2014年   28886篇
  2013年   88216篇
  2012年   36557篇
  2011年   50015篇
  2010年   43855篇
  2009年   52120篇
  2008年   46105篇
  2007年   43567篇
  2006年   45130篇
  2005年   40278篇
  2004年   42194篇
  2003年   42034篇
  2002年   38561篇
  2001年   35645篇
  2000年   33322篇
  1999年   33519篇
  1998年   50974篇
  1997年   41775篇
  1996年   36047篇
  1995年   31967篇
  1994年   29641篇
  1993年   29565篇
  1992年   25855篇
  1991年   23135篇
  1990年   23581篇
  1989年   22465篇
  1988年   20989篇
  1987年   19277篇
  1986年   18716篇
  1985年   22011篇
  1984年   22060篇
  1983年   19969篇
  1982年   19027篇
  1981年   19140篇
  1980年   17767篇
  1979年   18224篇
  1978年   17540篇
  1977年   17431篇
  1976年   18684篇
  1975年   15779篇
  1974年   15278篇
  1973年   15399篇
  1972年   12880篇
排序方式: 共有10000条查询结果,搜索用时 15 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