首页 | 本学科首页   官方微博 | 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   6733篇
  免费   516篇
  国内免费   5篇
电工技术   66篇
综合类   1篇
化学工业   1742篇
金属工艺   178篇
机械仪表   173篇
建筑科学   263篇
矿业工程   22篇
能源动力   266篇
轻工业   944篇
水利工程   40篇
石油天然气   42篇
无线电   496篇
一般工业技术   1500篇
冶金工业   245篇
原子能技术   56篇
自动化技术   1220篇
  2024年   28篇
  2023年   64篇
  2022年   77篇
  2021年   219篇
  2020年   207篇
  2019年   176篇
  2018年   299篇
  2017年   329篇
  2016年   381篇
  2015年   225篇
  2014年   328篇
  2013年   663篇
  2012年   381篇
  2011年   506篇
  2010年   385篇
  2009年   404篇
  2008年   361篇
  2007年   327篇
  2006年   264篇
  2005年   192篇
  2004年   175篇
  2003年   148篇
  2002年   148篇
  2001年   80篇
  2000年   84篇
  1999年   76篇
  1998年   82篇
  1997年   74篇
  1996年   66篇
  1995年   49篇
  1994年   46篇
  1993年   38篇
  1992年   31篇
  1991年   30篇
  1990年   16篇
  1989年   21篇
  1988年   19篇
  1987年   15篇
  1986年   14篇
  1985年   26篇
  1984年   12篇
  1983年   12篇
  1982年   19篇
  1981年   18篇
  1980年   12篇
  1979年   14篇
  1978年   13篇
  1977年   15篇
  1976年   13篇
  1974年   11篇
排序方式: 共有7254条查询结果,搜索用时 46 毫秒
991.
992.
Neural Computing and Applications - In this paper we introduce an efficient soft demapping method for amplitude phase shift keying (APSK) constellations using extreme learning machine (ELM). The...  相似文献   
993.
994.
995.
Küçük  Ö.  Eraslan  O.  Eskitascioglu  G.  Belli  S. 《Strength of Materials》2020,52(2):317-324
Strength of Materials - The aims of this finite elemental stress analysis (FEA) study were to evaluate the effects of loading direction, crown coverage, and adjacent teeth on stress distribution in...  相似文献   
996.
In this study, the use of Cu and Ni interlayers have been investigated for functional core-rim composite part production with WC-Co 9?wt-% feedstock/steel. For this purpose, different experiments have been performed and joining condition, shear strength and microstructure of the intermediate region have been examined. It has been found that AISI 4340 insert/WC-Co have been joined and 85.8?MPa shear strength achieved, but high speed steel insert has not joined. Moreover, it has been determined that better results are obtained with Ni interlayer. Under the same conditions, when the 40?µm Ni interlayer has been used between AISI 4340 core and WC-Co rim, shear strength has been increased approximately twice and has been 162.7?MPa.  相似文献   
997.
The aim of this study was to develop alginate and zein films containing natamycin, a natural antifungal agent, in order to limit/prevent the mould growth on the surface of kashar cheeses. The films were prepared by casting, and characterized in terms of antimicrobial and mechanical properties (tensile strength, elongation-at-break, and elastic modulus), and their morphology was examined by scanning electron microscopy (SEM). Mechanical properties of the zein films were found to be weaker than the alginate films. SEM analysis indicated that alginate films have a more regular structure than zein films, and a more homogenous distribution was observed at lower concentrations of natamycin. The antifungal activities of both films increased as the natamycin concentration (100, 200, 500, 1000, 2000, and 4000 ppm) increased; however, alginate films exhibited relatively high antifungal activity. The effects of films on the shelf life of kashar cheeses inoculated with Aspergillus niger and Penicillium camemberti were investigated during their storage under refrigerator conditions for 45 days. At high-natamycin concentrations, zein films showed higher antifungal activity against both fungi at the end of the storage period.  相似文献   
998.
999.
1000.
To ensure the marketing of fresh fish‐based products, it is necessary to develop fast methods that assess its freshness in real time. This study therefore evaluated the applicability of a photochromic time–temperature indicator (TTI) to monitor the time and temperature history during the period of validity of the whole fish of the cobia specimen stored in ice. The TTI response was both visibly interpreted as well as adaptable to measurement using suitable equipment. The results showed that the smart indicator activated during 6 s of ultraviolet light showed a similar rate of deterioration of the analysed product visual response, proving to be a dynamic shelf life indicator that can assure consumers the ultimate quality point of the entire cobia easily, cheaply and accurately.  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