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   11564篇
  免费   1017篇
  国内免费   1394篇
化学   710篇
晶体学   16篇
力学   624篇
综合类   303篇
数学   10416篇
物理学   1906篇
  2024年   14篇
  2023年   128篇
  2022年   117篇
  2021年   188篇
  2020年   217篇
  2019年   274篇
  2018年   259篇
  2017年   301篇
  2016年   322篇
  2015年   252篇
  2014年   518篇
  2013年   780篇
  2012年   471篇
  2011年   673篇
  2010年   629篇
  2009年   809篇
  2008年   881篇
  2007年   957篇
  2006年   779篇
  2005年   704篇
  2004年   532篇
  2003年   612篇
  2002年   522篇
  2001年   405篇
  2000年   472篇
  1999年   418篇
  1998年   386篇
  1997年   299篇
  1996年   226篇
  1995年   122篇
  1994年   130篇
  1993年   78篇
  1992年   59篇
  1991年   53篇
  1990年   43篇
  1989年   28篇
  1988年   33篇
  1987年   16篇
  1986年   14篇
  1985年   42篇
  1984年   34篇
  1983年   18篇
  1982年   29篇
  1981年   19篇
  1980年   20篇
  1979年   25篇
  1978年   16篇
  1977年   13篇
  1976年   9篇
  1936年   5篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
Boundedness of commutators on homogeneous Herz spaces   总被引:9,自引:0,他引:9  
The boundedness on homogeneous Herz spaces is established for a large class of linear commutators generated by BMO(R n ) functions and linear operators of rough kernels which include the Calderón-Zygmund operators and the Ricci-Stein oRfiUatory singular integrals with rough kernels. Project supponed in pan by the National h’atural Science Foundation of China (Grant No. 19131080) and the NEDF of China.  相似文献   
5.
A general theory of operators on Boson Fock space is discussed in terms of the white noise distribution theory on Gaussian space (white noise calculus). An integral kernel operator is generalized from two aspects: (i) The use of an operator-valued distribution as an integral kernel leads us to the Fubini type theorem which allows an iterated integration in an integral kernel operator. As an application a white noise approach to quantum stochastic integrals is discussed and a quantum Hitsuda–Skorokhod integral is introduced. (ii) The use of pointwise derivatives of annihilation and creation operators assures the partial integration in an integral kernel operator. In particular, the particle flux density becomes a distribution with values in continuous operators on white noise functions and yields a representation of a Lie algebra of vector fields by means of such operators.  相似文献   
6.
In this note, we use inexact Newton-like methods to find solutions of nonlinear operator equations on Banach spaces with a convergence structure. Our technique involves the introduction of a generalized norm as an operator from a linear space into a partially ordered Banach space. In this way, the metric properties of the examined problem can be analyzed more precisely. Moreover, this approach allows us to derive from the same theorem, on the one hand, semilocal results of Kantorovich-type, and on the other hand, global results based on monotonicity considerations. By imposing very general Lipschitz-like conditions on the operators involved, on the one hand, we cover a wider range of problems, and on the other hand, by choosing our operators appropriately, we can find sharper error bounds on the distances involved than before. Furthermore, we show that special cases of our results reduce to the corresponding ones already in the literature. Finally, several examples are being provided where our results compare favorably with earlier ones.  相似文献   
7.
This paper through discussing subdifferentiability and convexity of convex functions shows that a Banach space admits an equivalent uniformly [locally uniformly, strictly] convex norm if and only if there exists a continuous uniformly [locally uniformly, strictly] convex function on some nonempty open convex subset of the space and presents some characterizations of super-reflexive Banach spaces. Supported by NSFC  相似文献   
8.
Using the continuous shape space formalism, we develop an immune system model involving both B lymphocytes and antibody molecules. The binding and cross-linking of receptors on B cells stimulates the cells to divide and, with a lag, to secrete antibody. Using the method of multiple scales, we show how to correctly formulate long-time-scale equations for the population dynamics of B cells, the total antibody concentration, and rate of antibody secretion. We compare our model with previous phenomenological formulations.  相似文献   
9.
10.
谢胜利 《大学数学》2002,18(3):9-12
本文定义了二阶微分方程的弱 Carathéodory解 ,在不涉及紧型条件的情形下 ,直接用迭代法证明了 Banach空间二阶非线性常微分方程两点边值问题存在唯一解 ,并给出逼近解迭代序列的误差估计 ,对周期边值问题得到类似的结果  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