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   4932篇
  免费   209篇
  国内免费   11篇
化学   3413篇
晶体学   27篇
力学   144篇
数学   711篇
物理学   857篇
  2023年   40篇
  2022年   50篇
  2021年   63篇
  2020年   63篇
  2019年   65篇
  2018年   93篇
  2017年   68篇
  2016年   150篇
  2015年   135篇
  2014年   149篇
  2013年   314篇
  2012年   322篇
  2011年   362篇
  2010年   215篇
  2009年   196篇
  2008年   305篇
  2007年   299篇
  2006年   252篇
  2005年   246篇
  2004年   237篇
  2003年   170篇
  2002年   171篇
  2001年   114篇
  2000年   120篇
  1999年   85篇
  1998年   61篇
  1997年   35篇
  1996年   68篇
  1995年   50篇
  1994年   52篇
  1993年   48篇
  1992年   34篇
  1991年   46篇
  1990年   42篇
  1989年   36篇
  1988年   33篇
  1987年   29篇
  1986年   29篇
  1985年   39篇
  1984年   41篇
  1983年   26篇
  1982年   28篇
  1981年   23篇
  1980年   19篇
  1979年   17篇
  1978年   22篇
  1977年   16篇
  1976年   8篇
  1975年   11篇
  1973年   9篇
排序方式: 共有5152条查询结果,搜索用时 15 毫秒
1.
Journal of Analytical Chemistry - The present development involved a flow injection strategy using a mini-column of multiwalled carbon nanotubes and fluorescent detection (λex of 283 nm,...  相似文献   
2.
Meccanica - In this work we study, from the numerical point of view, a one-dimensional thermoelastic problem where the thermal law is of type III. Quasi-static microvoids are also assumed within...  相似文献   
3.
4.
Abstract

Realistic stochastic modeling is increasingly requiring the use of bounded noises. In this work, properties and relationships of commonly employed bounded stochastic processes are investigated within a solid mathematical ground. Four families are object of investigation: the Sine-Wiener (SW), the Doering–Cai–Lin (DCL), the Tsallis–Stariolo–Borland (TSB), and the Kessler–Sørensen (KS) families. We address mathematical questions on existence and uniqueness of the processes defined through Stochastic Differential Equations, which often conceal non-obvious behavior, and we explore the behavior of the solutions near the boundaries of the state space. The expression of the time-dependent probability density of the Sine-Wiener noise is provided in closed form, and a close connection with the Doering–Cai–Lin noise is shown. Further relationships among the different families are explored, pathwise and in distribution. Finally, we illustrate an analogy between the Kessler–Sørensen family and Bessel processes, which allows to relate the respective local times at the boundaries.  相似文献   
5.
6.
7.
8.
We consider Ising-spin systems starting from an initial Gibbs measure ν and evolving under a spin-flip dynamics towards a reversible Gibbs measure μ≠ν. Both ν and μ are assumed to have a translation-invariant finite-range interaction. We study the Gibbsian character of the measure νS(t) at time t and show the following: (1) For all ν and μ, νS(t) is Gibbs for small t. (2) If both ν and μ have a high or infinite temperature, then νS(t) is Gibbs for all t > 0. (3) If ν has a low non-zero temperature and a zero magnetic field and μ has a high or infinite temperature, then νS(t) is Gibbs for small t and non-Gibbs for large t. (4) If ν has a low non-zero temperature and a non-zero magnetic field and μ has a high or infinite temperature, then νS(t) is Gibbs for small t, non-Gibbs for intermediate t, and Gibbs for large t. The regime where μ has a low or zero temperature and t is not small remains open. This regime presumably allows for many different scenarios. Received: 26 April 2001 / Accepted: 10 October 2001  相似文献   
9.
This Note deals with the controllability of Stokes and Navier–Stokes systems with distributed controls with support in possibly small subdomains. We first present a new global Carleman inequality for the solutions to Stokes-like systems that leads to the null controllability at any time T>0. Then, we present a local result concerning exact controllability to trajectories of the Navier–Stokes system. To cite this article: E. Fernández-Cara et al., C. R. Acad. Sci. Paris, Ser. I 338 (2004).  相似文献   
10.
We studied the effectiveness of potable water treatment processes that consist of the stages of coagulation-flocculation-decantation, using iron-based coagulants, in eliminating gamma-emitting man-made radioisotopes of cesium, strontium, and americium from two natural waters with different degrees of mineralization. The resulting decontamination was found to depend on the chemical behavior of each of the radionuclides considered, on the pH at which the process of coagulation is carried out, and on the concentration of the other stable cations present. This revised version was published online in July 2006 with corrections to the Cover Date.  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