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   2949篇
  免费   119篇
  国内免费   50篇
化学   1768篇
晶体学   28篇
力学   149篇
综合类   16篇
数学   588篇
物理学   569篇
  2023年   21篇
  2022年   23篇
  2021年   46篇
  2020年   67篇
  2019年   69篇
  2018年   75篇
  2017年   73篇
  2016年   116篇
  2015年   91篇
  2014年   123篇
  2013年   225篇
  2012年   193篇
  2011年   204篇
  2010年   191篇
  2009年   133篇
  2008年   163篇
  2007年   143篇
  2006年   129篇
  2005年   124篇
  2004年   87篇
  2003年   70篇
  2002年   102篇
  2001年   73篇
  2000年   56篇
  1999年   40篇
  1998年   38篇
  1997年   35篇
  1996年   39篇
  1995年   21篇
  1994年   21篇
  1993年   18篇
  1992年   14篇
  1991年   16篇
  1990年   19篇
  1989年   15篇
  1988年   9篇
  1986年   15篇
  1985年   12篇
  1984年   12篇
  1983年   18篇
  1982年   14篇
  1981年   22篇
  1980年   11篇
  1979年   11篇
  1978年   16篇
  1977年   12篇
  1976年   13篇
  1975年   14篇
  1974年   15篇
  1964年   8篇
排序方式: 共有3118条查询结果,搜索用时 15 毫秒
1.
2.
Kwak  Do Y.  Park  Hyeokjoo 《Numerical Algorithms》2022,91(1):449-471
Numerical Algorithms - We develop a formal construction of a pointwise divergence-free basis in the nonconforming virtual element method of arbitrary order for the Stokes problem introduced in Zhao...  相似文献   
3.
Nonlinear Dynamics - Two types of constitutive equations consisting of instantaneous and power type hereditary contributions are proposed in order to model generalized capacitor (inductor). The...  相似文献   
4.
5.
Journal of Applied and Industrial Mathematics - In this paper, we introduce a nonlinear Lanchester-type model involving supply units. The model describes a battle where the Blue party consisting of...  相似文献   
6.
Czechoslovak Mathematical Journal - We give a complete characterization of closed sets F ? ?2 whose distance function dF:= dist(·, F) is DC (i.e., is the difference of two convex...  相似文献   
7.
Respiratory infections are a real threat for humans, and therefore the pig model is of interest for studies. As one of a case for studies, Actinobacillus pleuropneumoniae (APP) caused infections and still worries many pig breeders around the world. To better understand the influence of pathogenic effect of APP on a respiratory system—lungs and tracheobronchial lymph nodes (TBLN), we aimed to employ matrix-assisted laser desorption/ionization time-of-flight mass spectrometry imaging (MALDI-TOF MSI). In this study, six pigs were intranasally infected by APP and two were used as non-infected control, and 48 cryosections have been obtained. MALDI-TOF MSI and immunohistochemistry (IHC) were used to study spatial distribution of infectious markers, especially interleukins, in cryosections of porcine tissues of lungs (necrotic area, marginal zone) and tracheobronchial lymph nodes (TBLN) from pigs infected by APP. CD163, interleukin 1β (IL-1β) and a protegrin-4 precursor were successfully detected based on their tryptic fragments. CD163 and IL-1β were confirmed also by IHC. The protegrin-4 precursor was identified by MALDI-TOF/TOF directly on the tissue cryosections. CD163, IL-1β and protegrin-4 precursor were all significantly (p < 0.001) more expressed in necrotic areas of lungs infected by APP than in marginal zone, TBLN and in control lungs.  相似文献   
8.
Physics of the Solid State - Changes in the structure and properties of the Ni1&nbsp;–&nbsp;xCuxFe2O4 ferrites-spinel magnetic nanoparticles depending on the Cu ion concentration (0...  相似文献   
9.
10.
A fully quantitative theory of the relationship between protein conformation and optical spectroscopy would facilitate deeper insights into biophysical and simulation studies of protein dynamics and folding. In contrast to intense bands in the far-ultraviolet, near-UV bands are much weaker and have been challenging to compute theoretically. We report some advances in the accuracy of calculations in the near-UV, which were realised through the consideration of the vibrational structure of the electronic transitions of aromatic side chains.  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