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   1517622篇
  免费   27582篇
  国内免费   6931篇
工业技术   1552135篇
  2021年   15434篇
  2020年   11831篇
  2019年   14614篇
  2018年   14863篇
  2017年   14047篇
  2016年   21063篇
  2015年   17373篇
  2014年   28783篇
  2013年   87924篇
  2012年   36204篇
  2011年   48509篇
  2010年   42238篇
  2009年   50397篇
  2008年   45409篇
  2007年   42628篇
  2006年   45651篇
  2005年   39907篇
  2004年   42458篇
  2003年   42307篇
  2002年   41364篇
  2001年   38381篇
  2000年   36652篇
  1999年   35634篇
  1998年   46985篇
  1997年   40611篇
  1996年   36362篇
  1995年   31517篇
  1994年   29582篇
  1993年   29128篇
  1992年   26543篇
  1991年   23643篇
  1990年   23880篇
  1989年   22951篇
  1988年   21455篇
  1987年   19723篇
  1986年   19194篇
  1985年   22582篇
  1984年   22703篇
  1983年   20577篇
  1982年   19432篇
  1981年   19183篇
  1980年   17832篇
  1979年   18488篇
  1978年   17681篇
  1977年   17741篇
  1976年   19300篇
  1975年   15888篇
  1974年   15449篇
  1973年   15523篇
  1972年   13088篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
21.
Refractories and Industrial Ceramics - The paper introduces a promising technology for utilizing a traditional scheme for implementing a flow-through micro-arc oxidation method to restore localized...  相似文献   
22.
Theoretical Foundations of Chemical Engineering - On the basis of the classic concepts of the theory of solid-phase combustion, for the first time, a model with a detailed scheme of chemical...  相似文献   
23.
24.
Multimedia Tools and Applications - Recently, many concepts in technology has been changed. According to the digital transformation trends, Internet of Things (IoT) represents an interested...  相似文献   
25.
In this study, dilute chemical bath deposition technique has been used to deposit CdZnS thin films on soda-lime glass substrates. The structural, morphological, optoelectronic properties of as-grown films have been investigated as a function of different Zn2+ precursor concentrations. The X-ray diffractogram of CdS thin-film reveals a peak corresponding to (002) plane with wurtzite structure, and the peak shift has been observed with the increase of the Zn2+ concentration upon formation of CdZnS thin film. From morphological studies, it has been revealed that the diluted chemical bath deposition technique provides homogeneous distribution of film on the substrate even at a lower concentration of Zn2+. Optical characterization has shown that the transparency of the film is influenced by Zn2+ concentration and when the Zn2+ concentration is varied from 0 M to 0.0256 M, bandgap values of resulting films range from 2.42 eV to 3.90 eV while. Furthermore, electrical properties have shown that with increasing zinc concentration the resistivity of the film increases. Finally, numerical simulation validates and suggests that CdZnS buffer layer with composition of 0.0032 M Zn2+ concentration would be a promising candidate in CIGS solar cell.  相似文献   
26.
Combustion, Explosion, and Shock Waves - Results of a numerical study of mixing, ignition, and combustion of a cold hydrogen jet propagating along the lower wall of a channel parallel to a...  相似文献   
27.
Multimedia Tools and Applications - In this work, a new fuzzy logic-based algorithm is proposed for the enhancement of low light color images. A generalization of a fuzzy set known as an...  相似文献   
28.
Multimedia Tools and Applications - Endometriosis is a common gynecologic condition typically treated via laparoscopic surgery. Its visual versatility makes it hard to identify for non-specialized...  相似文献   
29.
Multimedia Tools and Applications - The three-dimensional models of brain tumors serve as diagnostic assistance for physicians, surgeons, and radiologists. The proposed system establishes an...  相似文献   
30.

We discuss the temperature dependence of a common low temperature local thermometer, a tunnel junction between a superconductor and a normal metal (NIS junction). Towards the lowest temperatures its characteristics tend to saturate, which is usually attributed to selfheating effects. In this technical note, we reanalyze this saturation and show that the temperature independent subgap current of the junction alone explains in some cases the low temperature behavior quantitatively.

  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