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   664篇
  免费   26篇
  国内免费   2篇
化学   421篇
晶体学   7篇
力学   25篇
数学   102篇
物理学   137篇
  2022年   8篇
  2021年   19篇
  2020年   15篇
  2019年   20篇
  2018年   13篇
  2017年   18篇
  2016年   31篇
  2015年   23篇
  2014年   25篇
  2013年   54篇
  2012年   48篇
  2011年   59篇
  2010年   28篇
  2009年   40篇
  2008年   46篇
  2007年   35篇
  2006年   30篇
  2005年   22篇
  2004年   27篇
  2003年   11篇
  2002年   18篇
  2001年   12篇
  2000年   10篇
  1999年   4篇
  1998年   7篇
  1996年   6篇
  1995年   9篇
  1994年   7篇
  1993年   2篇
  1992年   3篇
  1991年   6篇
  1989年   3篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1985年   3篇
  1983年   2篇
  1982年   2篇
  1979年   3篇
  1978年   1篇
  1977年   3篇
  1976年   1篇
  1974年   1篇
  1966年   1篇
  1932年   1篇
  1914年   1篇
  1913年   1篇
  1905年   1篇
  1904年   1篇
  1890年   1篇
排序方式: 共有692条查询结果,搜索用时 15 毫秒
1.
2.
Journal of Solid State Electrochemistry - The present work proposes a new electrochemical sulfite biosensor based on babassu mesocarp nanoparticles (BMNPs) immobilized on the surface of a pyrolytic...  相似文献   
3.
Journal of Dynamics and Differential Equations - In this paper we focus on a class of symmetric vector fields in the context of singularly perturbed fast-slow dynamical systems. Our main question...  相似文献   
4.
5.
Journal of Sol-Gel Science and Technology - Lithium ferrite (LiFe5O8) in the cubic crystal system is a very important and versatile material for several technological applications as it possesses...  相似文献   
6.
Cellulose - Core–shell nanoparticles (NPs) based on metal oxides, namely magnesium oxide (MgO) and silica (SiO2), are a fantastic alternative for natural fibers’ functionalization. In...  相似文献   
7.
Singular perturbations problems in dimension three which are approximations of discontinuous vector fields are studied in this paper. The main result states that the regularization process developed by Sotomayor and Teixeira produces a singular problem for which the discontinuous set is a center manifold. Moreover, the definition of sliding vector field coincides with the reduced problem of the corresponding singular problem for a class of vector fields.   相似文献   
8.
The phase behaviour of a number of N‐alkylimidazolium salts was studied using polarizing optical microscopy, differential scanning calorimetry and X‐ray diffraction. Two of these compounds exhibit lamellar mesophases at temperatures above 50°C. In these systems, the liquid crystalline behaviour may be induced at room temperature by shear. Sheared films of these materials, observed between crossed polarisers, have a morphology that is typical of (wet) liquid foams: they partition into dark domains separated by brighter (birefringent) walls, which are approximately arcs of circle and meet at “Plateau borders” with three or more sides. Where walls meet three at a time, they do so at approximately 120° angles. These patterns coarsen with time and both T1 and T2 processes have been observed, as in foams. The time evolution of domains is also consistent with von Neumann's law. We conjecture that the bright walls are regions of high concentration of defects produced by shear, and that the system is dominated by the interfacial tension between these walls and the uniform domains. The control of self‐organised monodomains, as observed in these systems, is expected to play an important role in potential applications.  相似文献   
9.
The European Physical Journal C - We argue that high-quality data on the reaction $$e^+e^-\rightarrow \pi ^+\pi ^-\eta $$ will allow one to determine the doubly-virtual form factor $$\eta...  相似文献   
10.
To improve physical motivation of mechanical modeling for semi-crystalline polymers, a better understanding of micro-mechanisms and a quantification of the mechanical response at the microstructure scale are needed. Strain field evolutions during deformation would be useful information but experimental techniques are still lacking for these materials. In this paper, an in-situ Digital Image Correlation (DIC) technique in the Scanning Electron Microscope (SEM) was developed to access strain fields at the spherulitic scale of a polypropylene. The evolution of strain heterogeneities during deformation were analyzed and correlated to the microstructure.  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