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   180204篇
  免费   911篇
  国内免费   265篇
化学   90073篇
晶体学   2636篇
力学   9413篇
综合类   7篇
数学   20993篇
物理学   58258篇
  2020年   1865篇
  2019年   2301篇
  2018年   3414篇
  2017年   3538篇
  2016年   4178篇
  2015年   1874篇
  2014年   3623篇
  2013年   7088篇
  2012年   5571篇
  2011年   6624篇
  2010年   5551篇
  2009年   5664篇
  2008年   6391篇
  2007年   6350篇
  2006年   5650篇
  2005年   5002篇
  2004年   4845篇
  2003年   4384篇
  2002年   4528篇
  2001年   5006篇
  2000年   3696篇
  1999年   2832篇
  1998年   2610篇
  1997年   2461篇
  1996年   2258篇
  1995年   2051篇
  1994年   2007篇
  1993年   2044篇
  1992年   2074篇
  1991年   2381篇
  1990年   2315篇
  1989年   2386篇
  1988年   2264篇
  1987年   2299篇
  1986年   2128篇
  1985年   2657篇
  1984年   2672篇
  1983年   2320篇
  1982年   2376篇
  1981年   2278篇
  1980年   2078篇
  1979年   2395篇
  1978年   2548篇
  1977年   2640篇
  1976年   2733篇
  1975年   2539篇
  1974年   2467篇
  1973年   2635篇
  1972年   2154篇
  1971年   1973篇
排序方式: 共有10000条查询结果,搜索用时 490 毫秒
61.
62.
63.
64.
65.
66.
67.
68.
Russian Journal of General Chemistry - A method was developed for the synthesis of an organofluorine derivative of β-D-ribofuranoside. Biological tests revealed high insecticidal activity and...  相似文献   
69.
The current study attempted, for the first time, to qualitatively and quantitatively determine the phytochemical components of Elatostema papillosum methanol extract and their biological activities. The present study represents an effort to correlate our previously reported biological activities with a computational study, including molecular docking, and ADME/T (absorption, distribution, metabolism, and excretion/toxicity) analyses, to identify the phytochemicals that are potentially responsible for the antioxidant, antidepressant, anxiolytic, analgesic, and anti-inflammatory activities of this plant. In the gas chromatography-mass spectroscopy analysis, a total of 24 compounds were identified, seven of which were documented as being bioactive based on their binding affinities. These seven were subjected to molecular docking studies that were correlated with the pharmacological outcomes. Additionally, the ADME/T properties of these compounds were evaluated to determine their drug-like properties and toxicity levels. The seven selected, isolated compounds displayed favorable binding affinities to potassium channels, human serotonin receptor, cyclooxygenase-1 (COX-1), COX-2, nuclear factor (NF)-κB, and human peroxiredoxin 5 receptor proteins. Phytol acetate, and terpene compounds identified in E. papillosum displayed strong predictive binding affinities towards the human serotonin receptor. Furthermore, 3-trifluoroacetoxypentadecane showed a significant binding affinity for the KcsA potassium channel. Eicosanal showed the highest predicted binding affinity towards the human peroxiredoxin 5 receptor. All of these findings support the observed in vivo antidepressant and anxiolytic effects and the in vitro antioxidant effects observed for this extract. The identified compounds from E. papillosum showed the lowest binding affinities towards COX-1, COX-2, and NF-κB receptors, which indicated the inconsequential impacts of this extract against the activities of these three proteins. Overall, E. papillosum appears to be bioactive and could represent a potential source for the development of alternative medicines; however, further analytical experiments remain necessary.  相似文献   
70.
Molecular dynamics simulation was performed to study the formation of cluster structure, interfaces, and surfaces with different curvature radii in a perfect nanocrystal passed through by a nonlinear wave. It is shown that this process is a type of nanostructure self-organization in response to an external energy flux with subsequent development of a strong rotational field.  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