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   904篇
  免费   99篇
  国内免费   151篇
化学   5篇
力学   71篇
综合类   33篇
数学   1026篇
物理学   19篇
  2024年   2篇
  2023年   9篇
  2022年   9篇
  2021年   9篇
  2020年   21篇
  2019年   24篇
  2018年   28篇
  2017年   34篇
  2016年   36篇
  2015年   32篇
  2014年   33篇
  2013年   59篇
  2012年   31篇
  2011年   41篇
  2010年   45篇
  2009年   62篇
  2008年   55篇
  2007年   63篇
  2006年   60篇
  2005年   52篇
  2004年   48篇
  2003年   61篇
  2002年   42篇
  2001年   36篇
  2000年   38篇
  1999年   49篇
  1998年   25篇
  1997年   24篇
  1996年   25篇
  1995年   12篇
  1994年   26篇
  1993年   9篇
  1992年   5篇
  1991年   7篇
  1990年   5篇
  1989年   2篇
  1988年   3篇
  1986年   1篇
  1985年   2篇
  1984年   5篇
  1983年   2篇
  1982年   4篇
  1981年   3篇
  1980年   1篇
  1979年   5篇
  1978年   3篇
  1977年   2篇
  1975年   1篇
  1972年   1篇
  1936年   1篇
排序方式: 共有1154条查询结果,搜索用时 15 毫秒
31.
《Mathematische Nachrichten》2017,290(2-3):349-366
In this paper, we give a new characterization for the boundedness of weighted differentiation composition operator from logarithmic Bloch spaces to Bloch‐type spaces and calculate its essential norm in terms of the n‐th power of induced analytic self‐map on the unit disk. From which a sufficient and necessary condition of compactness of this operator follows immediately.  相似文献   
32.
In this paper,an initial boundary value problem with homogeneous Neumann boundary condition is studied for a reaction-diffusion system which models the spread of infectious diseases within two population groups by means of self and criss-cross infection mechanism. Existence,uniqueness and boundedness of the nonnegative global solution (u1,u2,u3,u4),existence of the limit of the solution as t→+∞,namely,(u1,u2,u3,u4)→(u*1,0,u*3,0),are proved.  相似文献   
33.
Applying the improved Rayleigh SchrSdinger perturbation theory based on an integral equation to helium-like ions in ground states and treating electron correlations as perturbations, we obtain the second-order corrections to wavefunctions consisting of a few terms and the third-order corrections to energicity. It is demonstrated that the corrected wavefunctions are bounded and quadratically integrable, and the corresponding perturbation series is convergent. The results clear off the previous distrust for the convergence in the quantum perturbation theory and show a reciprocal development on the quantum perturbation problem of the ground state helium-like systems.  相似文献   
34.
In this paper, we suggest and analyze a three-step iterative scheme for asymptotically nonexpansive mappings in Banach spaces. The new iterative scheme includes Ishikawa-type and Mann-type interations as special cases. The results obtained in this paper represent an extension as well as refinement of previous known results.  相似文献   
35.
UNIFORMBOUNDEDNESSANDUNIFORMSTABILITYOFAKINDOFDELAY──DIFFERENTIALEQUATIONS¥ZhengBunan(GuangxiNormalUniversity)Abstract:Thispa...  相似文献   
36.
Let be a nonempty closed convex subset of a real Banach space and be a Lipschitz pseudocontractive self-map of with . An iterative sequence is constructed for which as . If, in addition, is assumed to be bounded, this conclusion still holds without the requirement that Moreover, if, in addition, has a uniformly Gâteaux differentiable norm and is such that every closed bounded convex subset of has the fixed point property for nonexpansive self-mappings, then the sequence converges strongly to a fixed point of . Our iteration method is of independent interest.

  相似文献   

37.
Klimkin  V. M.  Sribnaya  T. A. 《Mathematical Notes》2003,74(1-2):56-63
Conditions for the uniform continuity of a family of weakly regular set functions defined on an algebra of subsets of a -topological space (T,) and taking values in an arbitrary topological space are found.  相似文献   
38.
Abstract For the multidimensional ARMA system A(z)y_k=C(z)w_k it is shown that stability(det A(z)≠0,z:│z│≤1)of A(z) is equivalent to the trajectory boundedness in the mean square sense(MSS)which,as a rule,is a consequence of a successful stochastic adaptive control leading the closed-loop of an ARMAXsystem to a steady state ARMA system.In comparison with existing results the stability condition imposed onC(z)is no longer needed.The only structural requirement on the system is that det A(z) and det C(z) have nounstable common factor.  相似文献   
39.
We show that for below certain critical indices there are functions whose Jacobi or Laguerre expansions have almost everywhere divergent Cesàro and Riesz means of order .

  相似文献   

40.
mapping properties will be established in this paper for singular Radon transforms with rough kernels defined by translates of a real-analytic submanifold in .

  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