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   1565360篇
  免费   28140篇
  国内免费   7114篇
工业技术   1600614篇
  2021年   15680篇
  2020年   12038篇
  2019年   14805篇
  2018年   17011篇
  2017年   16424篇
  2016年   22116篇
  2015年   17626篇
  2014年   28953篇
  2013年   88295篇
  2012年   37616篇
  2011年   51339篇
  2010年   44216篇
  2009年   52133篇
  2008年   47447篇
  2007年   45184篇
  2006年   46382篇
  2005年   41541篇
  2004年   43380篇
  2003年   43100篇
  2002年   41891篇
  2001年   38957篇
  2000年   37137篇
  1999年   36569篇
  1998年   53061篇
  1997年   44115篇
  1996年   38597篇
  1995年   32797篇
  1994年   30561篇
  1993年   30183篇
  1992年   26828篇
  1991年   24004篇
  1990年   24204篇
  1989年   23299篇
  1988年   21798篇
  1987年   20047篇
  1986年   19520篇
  1985年   22884篇
  1984年   22853篇
  1983年   20713篇
  1982年   19522篇
  1981年   19624篇
  1980年   18259篇
  1979年   18840篇
  1978年   18020篇
  1977年   18126篇
  1976年   19941篇
  1975年   15994篇
  1974年   15524篇
  1973年   15611篇
  1972年   13177篇
排序方式: 共有10000条查询结果,搜索用时 15 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