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   8026篇
  免费   477篇
  国内免费   14篇
电工技术   85篇
综合类   3篇
化学工业   1931篇
金属工艺   177篇
机械仪表   147篇
建筑科学   301篇
矿业工程   14篇
能源动力   254篇
轻工业   760篇
水利工程   75篇
石油天然气   28篇
武器工业   6篇
无线电   606篇
一般工业技术   1632篇
冶金工业   1046篇
原子能技术   48篇
自动化技术   1404篇
  2023年   55篇
  2022年   94篇
  2021年   169篇
  2020年   162篇
  2019年   137篇
  2018年   189篇
  2017年   201篇
  2016年   260篇
  2015年   178篇
  2014年   280篇
  2013年   619篇
  2012年   455篇
  2011年   562篇
  2010年   380篇
  2009年   384篇
  2008年   518篇
  2007年   448篇
  2006年   381篇
  2005年   315篇
  2004年   289篇
  2003年   252篇
  2002年   214篇
  2001年   134篇
  2000年   117篇
  1999年   125篇
  1998年   163篇
  1997年   130篇
  1996年   126篇
  1995年   103篇
  1994年   127篇
  1993年   87篇
  1992年   78篇
  1991年   56篇
  1990年   56篇
  1989年   70篇
  1988年   52篇
  1987年   27篇
  1986年   35篇
  1985年   49篇
  1984年   50篇
  1983年   33篇
  1982年   34篇
  1981年   43篇
  1980年   34篇
  1979年   25篇
  1978年   28篇
  1977年   22篇
  1976年   18篇
  1975年   20篇
  1974年   25篇
排序方式: 共有8517条查询结果,搜索用时 13 毫秒
1.
Journal of Materials Science - For transformers and inductors to meet the world’s growing demand for electrical power, more efficient soft magnetic materials with high saturation magnetic...  相似文献   
2.
Multimedia Tools and Applications - Changes in appearance present a tremendous problem for the visual localization of an autonomous vehicle in outdoor environments. Data association between the...  相似文献   
3.
Treating neuroinflammation-related injuries and disorders through manipulation of neuroinflammation functions is being heralded as a new therapeutic strategy. In this study, a novel pectic galactan (PG) polysaccharide based gene therapy approach is developed for targeting reactive gliosis in neuroinflammation. Galectin-3 (Gal-3) is a cell protein with a high affinity to β-galactoside sugars and is highly expressed in reactive gliosis. Since PG carries galactans, it can target reactive gliosis via specific carbohydrate interaction between galactan and Gal-3 on the cell membrane, and therefore can be utilized as a carrier for delivering genes to these cells. The carrier is synthesized by modifying quaternary ammonium groups on the PG. The resulting quaternized PG (QPG) is found to form complexes with plasmid DNA with a mean diameter of 100 nm and have the characteristics required for targeted gene therapy. The complexes efficiently condense large amounts of plasmid per particle and successfully bind to Gal-3. The in vivo study shows that the complexes are biocompatible and safe for administration and can selectively transfect reactive glial cells of an induced cortical lesion. The results confirm that this PG-based delivery system is a promising platform for targeting Gal-3 overexpressing neuroinflammation cells for treating neuroinflammation-related injuries and neurodegenerative diseases.  相似文献   
4.
5.
6.
Bile acids have been reported as important cofactors promoting human and murine norovirus (NoV) infections in cell culture. The underlying mechanisms are not resolved. Through the use of chemical shift perturbation (CSP) NMR experiments, we identified a low-affinity bile acid binding site of a human GII.4 NoV strain. Long-timescale MD simulations reveal the formation of a ligand-accessible binding pocket of flexible shape, allowing the formation of stable viral coat protein–bile acid complexes in agreement with experimental CSP data. CSP NMR experiments also show that this mode of bile acid binding has a minor influence on the binding of histo-blood group antigens and vice versa. STD NMR experiments probing the binding of bile acids to virus-like particles of seven different strains suggest that low-affinity bile acid binding is a common feature of human NoV and should therefore be important for understanding the role of bile acids as cofactors in NoV infection.  相似文献   
7.
8.
9.
A sizable part (~2%) of the human genome encodes for proteases. They are involved in many physiological processes, such as development, reproduction and inflammation, but also play a role in pathology. Mast cells (MC) contain a variety of MC specific proteases, the expression of which may differ between various MC subtypes. Amongst these proteases, chymase represents up to 25% of the total proteins in the MC and is released from cytoplasmic granules upon activation. Once secreted, it cleaves the targets in the local tissue environment, but may also act in lymph nodes infiltrated by MC, or systemically, when reaching the circulation during an inflammatory response. MC have been recognized as important components in the development of kidney disease. Based on this observation, MC chymase has gained interest following the discovery that it contributes to the angiotensin-converting enzyme’s independent generation of angiotensin II, an important inflammatory mediator in the development of kidney disease. Hence, progress regarding its role has been made based on studies using inhibitors but also on mice deficient in MC protease 4 (mMCP-4), the functional murine counterpart of human chymase. In this review, we discuss the role and actions of chymase in kidney disease. While initially believed to contribute to pathogenesis, the accumulated data favor a more subtle view, indicating that chymase may also have beneficial actions.  相似文献   
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