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   65064篇
  免费   7418篇
  国内免费   3925篇
电工技术   5521篇
技术理论   3篇
综合类   5181篇
化学工业   9792篇
金属工艺   3447篇
机械仪表   4275篇
建筑科学   5598篇
矿业工程   2194篇
能源动力   1733篇
轻工业   6113篇
水利工程   1471篇
石油天然气   2803篇
武器工业   732篇
无线电   7951篇
一般工业技术   6881篇
冶金工业   2318篇
原子能技术   839篇
自动化技术   9555篇
  2024年   193篇
  2023年   1255篇
  2022年   2494篇
  2021年   3265篇
  2020年   2667篇
  2019年   1977篇
  2018年   2330篇
  2017年   2488篇
  2016年   2260篇
  2015年   3419篇
  2014年   4132篇
  2013年   4688篇
  2012年   5332篇
  2011年   5535篇
  2010年   4690篇
  2009年   4204篇
  2008年   4051篇
  2007年   3708篇
  2006年   3447篇
  2005年   2779篇
  2004年   1920篇
  2003年   1416篇
  2002年   1255篇
  2001年   1089篇
  2000年   1069篇
  1999年   904篇
  1998年   685篇
  1997年   561篇
  1996年   547篇
  1995年   419篇
  1994年   362篇
  1993年   265篇
  1992年   242篇
  1991年   175篇
  1990年   134篇
  1989年   138篇
  1988年   69篇
  1987年   50篇
  1986年   37篇
  1985年   29篇
  1984年   19篇
  1983年   11篇
  1982年   24篇
  1981年   15篇
  1980年   26篇
  1979年   6篇
  1977年   1篇
  1966年   2篇
  1959年   13篇
  1951年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Shu  Fei  Dinneen  Jesse David  Chen  Shiji 《Scientometrics》2022,127(6):3613-3628
Scientometrics - Examining the relationships among scientific disciplines is important today, but existing methods are limited by the contents and structure of their bibliographic databases. We...  相似文献   
6.
7.
This study aims to fabricate mineral-loading nanocarriers using natural materials. The interaction patterns between ovalbumin (OVA) and four water-soluble polyphenols, namely ferulic acid (FA), (-)-Epigallo-catechin 3-gallate (EGCG), gallic acid (GA) and epicatechin (EC), were investigated. Results showed that the optimised conditions for preparing stable OVA–polyphenol complexes are at the OVA–polyphenol ratio of 4:1 at pH 6, under which OVA–FA and OVA–EGCG showed the highest stability and mineral-loading capacity among four OVA–polyphenol complexes. The fluorescence results indicated that the addition of EGCG and FA induced a significant fluorescence quenching to OVA. The interaction between OVA and polyphenols involved hydrogen bonding, hydrophobic interaction and electrostatic interaction. Fourier transform infrared spectroscopy (FTIR) analysis suggested that both FA and EGCG enhanced the stability and orderliness of the structure of OVA. The transmission electron microscopy images also exhibited the spherical structure of OVA after the addition of FA and EGCG. Furthermore, scanning electron microscope–energy dispersive X-ray spectrum results suggested that OVA–FA and OVA–EGCG complexes were better mineral carriers than OVA–GA and OVA–EC. This study may serve as the theoretical support for the promising application of OVA in the fabrication of mineral-loading nanocarriers in functional food and pharmaceutic.  相似文献   
8.
The present work was conducted to illustrate the mechanism of gel formation of myofibrillar proteins (MPs) under different microwave heating times. The results showed that the denaturation enthalpy (ΔH) of the MPs significantly decreased when the heating time increased from 3 to 9 s and then completely disappeared as the heating time progressed, indicating that the MPs gradually denatured and subsequently aggregated with increasing heating time, which was further verified by the changes in the secondary structure, electrophoretic bands, and gel properties (e.g., water holding capacity and textural profiles) of the MPs. Microstructural images indicated that the MP gel formed under 12 s had the most compact network, indicating that extended microwave heating time could induce quality deterioration of MP gels. Moreover, the hydrophobic forces, electrostatic forces, and disulphide bonds of the MPs gradually intensified with increasing microwave heating time, suggesting that both non-covalent and covalent bonds could promote molecular denaturation and subsequent aggregation of MPs. In addition, correlation analysis revealed that the changes in the molecular conformation of MPs induced by different microwave heating times could effectively regulate the formation of MP gels and their related properties.  相似文献   
9.
10.
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