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   2610篇
  免费   103篇
  国内免费   2篇
化学   1448篇
晶体学   2篇
力学   177篇
数学   607篇
物理学   481篇
  2023年   24篇
  2022年   13篇
  2021年   55篇
  2020年   39篇
  2019年   36篇
  2018年   57篇
  2017年   41篇
  2016年   116篇
  2015年   93篇
  2014年   86篇
  2013年   173篇
  2012年   144篇
  2011年   146篇
  2010年   113篇
  2009年   83篇
  2008年   129篇
  2007年   137篇
  2006年   123篇
  2005年   99篇
  2004年   96篇
  2003年   70篇
  2002年   75篇
  2001年   42篇
  2000年   39篇
  1999年   26篇
  1998年   22篇
  1997年   28篇
  1996年   28篇
  1995年   25篇
  1994年   21篇
  1993年   29篇
  1992年   29篇
  1991年   24篇
  1990年   27篇
  1989年   23篇
  1988年   17篇
  1986年   17篇
  1985年   19篇
  1984年   20篇
  1983年   20篇
  1982年   22篇
  1981年   22篇
  1980年   24篇
  1979年   15篇
  1978年   11篇
  1977年   16篇
  1976年   14篇
  1974年   13篇
  1973年   10篇
  1934年   11篇
排序方式: 共有2715条查询结果,搜索用时 156 毫秒
1.
We prove a well-posedness result for two pseudo-parabolic problems, which can be seen as two models for the same electrical conduction phenomenon in heterogeneous media, neglecting the magnetic field. One of the problems is the concentration limit of the other one, when the thickness of the dielectric inclusions goes to zero. The concentrated problem involves a transmission condition through interfaces, which is mediated by a suitable Laplace-Beltrami type equation.  相似文献   
2.
Letters in Mathematical Physics - We propose that the grand canonical topological string partition functions satisfy finite-difference equations in the closed string moduli. In the case of genus...  相似文献   
3.
4.
5.
This paper deals with the Cauchy–Dirichlet problem for the fractional Cahn–Hilliard equation. The main results consist of global (in time) existence of weak solutions, characterization of parabolic smoothing effects (implying under proper condition eventual boundedness of trajectories), and convergence of each solution to a (single) equilibrium. In particular, to prove the convergence result, a variant of the so-called ?ojasiewicz–Simon inequality is provided for the fractional Dirichlet Laplacian and (possibly) non-analytic (but C1) nonlinearities.  相似文献   
6.
7.
8.
By combining frontal polymerization and radical‐induced cationic polymerization, it was possible to cure thick samples of an epoxy monomer bleached by UV light. The effect of the relative amounts of cationic photoinitiator and radical initiator was thoroughly investigated and was related to the front's velocity and its maximum temperature. The materials obtained were characterized by quantitative conversion also in the deeper layers, not reached by UV light. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2066–2072, 2004  相似文献   
9.
We present a new generic problem solving approach for over-constrained problems based on Max-SAT. We first define a Boolean clausal form formalism, called soft CNF formulas, that deals with blocks of clauses instead of individual clauses, and that allows one to declare each block either as hard (i.e., must be satisfied by any solution) or soft (i.e., can be violated by some solution). We then present two Max-SAT solvers that find a truth assignment that satisfies all the hard blocks of clauses and the maximum number of soft blocks of clauses. Our solvers are branch and bound algorithms equipped with original lazy data structures, powerful inference techniques, good quality lower bounds, and original variable selection heuristics. Finally, we report an experimental investigation on a representative sample of instances (random 2-SAT, Max-CSP, graph coloring, pigeon hole and quasigroup completion) which provides experimental evidence that our approach is very competitive compared with the state-of-the-art approaches developed in the CSP and SAT communities. Research partially supported by projects TIN2004-07933-C03-03 and TIC2003-00950 funded by the Ministerio de Educación y Ciencia. The second author is supported by a grant Ramón y Cajal.  相似文献   
10.
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