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   2846篇
  免费   132篇
  国内免费   13篇
化学   2152篇
晶体学   10篇
力学   126篇
数学   327篇
物理学   376篇
  2023年   31篇
  2022年   59篇
  2021年   59篇
  2020年   67篇
  2019年   65篇
  2018年   43篇
  2017年   36篇
  2016年   89篇
  2015年   81篇
  2014年   94篇
  2013年   147篇
  2012年   217篇
  2011年   256篇
  2010年   124篇
  2009年   142篇
  2008年   218篇
  2007年   204篇
  2006年   207篇
  2005年   196篇
  2004年   169篇
  2003年   134篇
  2002年   115篇
  2001年   51篇
  2000年   28篇
  1999年   20篇
  1998年   20篇
  1997年   20篇
  1996年   22篇
  1995年   6篇
  1994年   8篇
  1993年   8篇
  1992年   14篇
  1991年   4篇
  1990年   1篇
  1989年   2篇
  1988年   6篇
  1987年   3篇
  1986年   1篇
  1985年   2篇
  1984年   3篇
  1982年   3篇
  1981年   3篇
  1980年   1篇
  1979年   1篇
  1978年   2篇
  1977年   3篇
  1976年   2篇
  1975年   1篇
  1974年   1篇
  1971年   1篇
排序方式: 共有2991条查询结果,搜索用时 15 毫秒
91.
A straightforward procedure leading to the flavone cirsimaritin and its 4′-O-β-d-glycosylation to afford cirsimarin, its corresponding flavone glucopyranoside, is described. The biological properties of cirsimarin, measured on human adipocytes, showed potent effects on both lipolysis and lipogenesis. Cirsimarin could therefore be considered as an efficient tool in the struggle against excessive adipose tissue deposition and as a potential candidate in the treatment of obesity.  相似文献   
92.
93.
This paper deals with the modelling and numerical simulation of isothermal bubbly flows with multi-size bubbles. The study of isothermal bubbly flows without phase change is a first step towards the more general study of boiling bubbly flows. Here, we are interested in taking into account the features of such isothermal flow associated to the multiple sizes of the different bubbles simultaneously present inside the flow. With this aim, several approaches have been developed. In this paper, two of these approaches are described and their results are compared to experimental data, as well as to those of an older approach assuming a single average size of bubbles. These two approaches are (i) the moment density approach for which two different expressions for the bubble diameter distribution function are proposed and (ii) the multi-field approach. All the models are implemented into the NEPTUNE_CFD code and are compared to a test performed on the MTLOOP facility. These comparisons show their respective merits and shortcomings in their available state of development.  相似文献   
94.
95.
In the era of systems biology, computational and high-throughput experimental biological approaches are increasingly being combined to provide global snapshots of entire genomes and proteomes under tissue- and disease-specific conditions. The aim is to identify proteins changing in concentration and/or post-translational state and/or location, and develop a better molecular level understanding of the operation of biological systems. Here we describe an approach for comparative proteomics that builds upon the combination of high-performance nano-scale separations with the high-mass measurement accuracy, mass-resolving power and sensitivity of Fourier transform ion cyclotron resonance mass spectrometry to provide broad dynamic range, comprehensive and quantitative proteome measurements.  相似文献   
96.
Straightforward access to anhydrovinblastine starting from the parent alkaloid leurosine is reported. The key deoxygenation step was first optimized on a model substrate. However, applied to leurosine, only the low-valent Cp2TiCl gave satisfactory results.  相似文献   
97.
Electrochemical blocking is a type of single-entity electrochemical measurement particularly well adapted to the detection of insulating particles. The digital detection of ultralow concentrations of artificial entities such as polymer particles or biotargets such as proteins and bacteria represents an exceptional opportunity for sensing applications. In this review, we explore the latest development in the field of electrochemical blocking and propose some perspectives.  相似文献   
98.
99.
100.
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