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   2587篇
  免费   127篇
  国内免费   4篇
化学   1866篇
晶体学   21篇
力学   69篇
数学   191篇
物理学   571篇
  2024年   8篇
  2023年   20篇
  2022年   78篇
  2021年   107篇
  2020年   88篇
  2019年   118篇
  2018年   117篇
  2017年   93篇
  2016年   124篇
  2015年   100篇
  2014年   111篇
  2013年   132篇
  2012年   193篇
  2011年   206篇
  2010年   141篇
  2009年   84篇
  2008年   139篇
  2007年   142篇
  2006年   155篇
  2005年   136篇
  2004年   101篇
  2003年   67篇
  2002年   65篇
  2001年   32篇
  2000年   19篇
  1999年   11篇
  1998年   20篇
  1997年   15篇
  1996年   17篇
  1995年   3篇
  1994年   12篇
  1993年   8篇
  1992年   7篇
  1991年   3篇
  1990年   4篇
  1989年   6篇
  1988年   2篇
  1987年   3篇
  1985年   6篇
  1984年   3篇
  1982年   3篇
  1981年   4篇
  1980年   2篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1975年   1篇
  1974年   3篇
  1970年   1篇
排序方式: 共有2718条查询结果,搜索用时 0 毫秒
101.
Russian Journal of Applied Chemistry - Method is suggested for obtaining biochar materials by treatment of a finely dispersed (≤0.1 mm) bark of aspen and(or) larch with a 40% formaldehyde...  相似文献   
102.
Technical Physics - Based on the analysis of results from different authors using direct numerical simulations of the liquid flow in a flat channel, the effect of Reynolds number on the...  相似文献   
103.
The effect of the promotion of nanocrystalline MgO aerogels with small amounts of vanadium and carbon on the destructive sorption of the Freons CF2Cl2 and CFCl3 was studied. It was found that the introduction of the promoters considerably shortened the induction period of the reaction. The pretreatment of samples modified with vanadium in an oxidizing or reducing atmosphere did not significantly affect the duration of the induction period. It was established that the acceleration of the reaction by fine-particle carbon did not depend on the mutual arrangement of carbon and MgO: on the surface of MgO nanoparticles, in the form of their mechanical mixture, or at separate positions in a reactor. It was concluded that the modifiers catalytically affect the interaction of MgO aerogels with Freons to accelerate the formation of active centers on the surface of their nanoparticles.  相似文献   
104.
Enterococcus faecalis is one of most important nosocomial and often multi‐antibiotic resistant pathogens responsible for infections that are difficult to treat. Previously, a cell‐wall polysaccharide termed diheteroglycan (DHG) was isolated and characterized as a promising vaccine candidate. However, the configuration of its lactic acid (LA) residue attached to the galactofuranoside unit was not assessed, although it influences conformation of DHG chain in terms of biological recognition and immune evasion. This study proves the R configuration of the LA residue by means of chemical analysis, investigation of intramolecular NMR nuclear Overhauser effects and molecular dynamics simulations of native DHG and corresponding R and S models, which were obtained by using pyranoside‐into‐furanoside rearrangement. As alternative treatment and prevention strategies for E. faecalis are desperately needed, this discovery may offer the prospect of a synthetic vaccine to actively immunize patients at risk.  相似文献   
105.
Nanofluidics encompasses a wide range of advanced approaches to study charge and mass transport at the nanoscale. Modern technologies allow us to develop and improve artificial nanofluidic platforms that confine ions in a way similar to single-ion channels in living cells. Therefore, nanofluidic platforms show great potential to act as a test field for theoretical models. This review aims to highlight ionic Coulomb blockade (ICB)—an effect that is proposed to be the key player of ion channel selectivity, which is based upon electrostatic exclusion limiting ion transport. Thus, in this perspective, we focus on the most promising approaches that have been reported on the subject. We consider ion confinements of various dimensionalities and highlight the most recent advancements in the field. Furthermore, we concentrate on the most critical obstacles associated with these studies and suggest possible solutions to advance the field further.  相似文献   
106.
107.
108.
Fast Fourier transform (FFT) based approaches have been successful in application to modeling of relatively rigid protein–protein complexes. Recently, we have been able to adapt the FFT methodology to treatment of flexible protein–peptide interactions. Here, we report our latest attempt to expand the capabilities of the FFT approach to treatment of flexible protein–ligand interactions in application to the D3R PL-2016-1 challenge. Based on the D3R assessment, our FFT approach in conjunction with Monte Carlo minimization off-grid refinement was among the top performing methods in the challenge. The potential advantage of our method is its ability to globally sample the protein–ligand interaction landscape, which will be explored in further applications.  相似文献   
109.
110.
In order to interpret results of temperature dependent Hall measurements in heteroepitaxial ZnO-thin films, we adopted a multilayer conductivity model considering carrier-transport through the interfacial layer with degenerate electron gas as well as the upper part of ZnO layers with lower conductivity. This model was applied to the temperature dependence of the carrier concentration and mobility measured by Hall effect in a ZnO-layer grown on c-sapphire with conventional high-temperature MgO and low-temperature ZnO buffer. We also compared our results with the results of maximum entropy mobility-spectrum analysis (MEMSA). The formation of the highly conductive interfacial layer was explained by analysis of transmission electron microscopy (TEM) images taken from similar layers.  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