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   1625606篇
  免费   37177篇
  国内免费   7025篇
工业技术   1669808篇
  2021年   15705篇
  2020年   13013篇
  2019年   17021篇
  2018年   19763篇
  2017年   19512篇
  2016年   25042篇
  2015年   20094篇
  2014年   31355篇
  2013年   91651篇
  2012年   40436篇
  2011年   54582篇
  2010年   46522篇
  2009年   54209篇
  2008年   50037篇
  2007年   47654篇
  2006年   48210篇
  2005年   43193篇
  2004年   45095篇
  2003年   44694篇
  2002年   43207篇
  2001年   40464篇
  2000年   38511篇
  1999年   38275篇
  1998年   61722篇
  1997年   49290篇
  1996年   42004篇
  1995年   34703篇
  1994年   31714篇
  1993年   31264篇
  1992年   26681篇
  1991年   24064篇
  1990年   24294篇
  1989年   23226篇
  1988年   21815篇
  1987年   20017篇
  1986年   19619篇
  1985年   22946篇
  1984年   22714篇
  1983年   20546篇
  1982年   19359篇
  1981年   19493篇
  1980年   18162篇
  1979年   18655篇
  1978年   17893篇
  1977年   18538篇
  1976年   21029篇
  1975年   16055篇
  1974年   15562篇
  1973年   15685篇
  1972年   13188篇
排序方式: 共有10000条查询结果,搜索用时 609 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