全文获取类型
收费全文 | 9858篇 |
免费 | 1013篇 |
国内免费 | 1194篇 |
专业分类
化学 | 258篇 |
力学 | 261篇 |
综合类 | 186篇 |
数学 | 9170篇 |
物理学 | 2190篇 |
出版年
2024年 | 19篇 |
2023年 | 108篇 |
2022年 | 114篇 |
2021年 | 164篇 |
2020年 | 246篇 |
2019年 | 344篇 |
2018年 | 303篇 |
2017年 | 313篇 |
2016年 | 350篇 |
2015年 | 252篇 |
2014年 | 511篇 |
2013年 | 821篇 |
2012年 | 435篇 |
2011年 | 582篇 |
2010年 | 556篇 |
2009年 | 752篇 |
2008年 | 740篇 |
2007年 | 736篇 |
2006年 | 633篇 |
2005年 | 561篇 |
2004年 | 464篇 |
2003年 | 478篇 |
2002年 | 462篇 |
2001年 | 292篇 |
2000年 | 319篇 |
1999年 | 308篇 |
1998年 | 264篇 |
1997年 | 240篇 |
1996年 | 148篇 |
1995年 | 82篇 |
1994年 | 81篇 |
1993年 | 49篇 |
1992年 | 44篇 |
1991年 | 36篇 |
1990年 | 22篇 |
1989年 | 25篇 |
1988年 | 22篇 |
1987年 | 8篇 |
1986年 | 9篇 |
1985年 | 21篇 |
1984年 | 27篇 |
1983年 | 16篇 |
1982年 | 25篇 |
1981年 | 14篇 |
1980年 | 22篇 |
1979年 | 12篇 |
1978年 | 10篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1936年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
设γ:[-1,1]→R~n是R~n中的曲线,沿曲线的γ的Hilbert变换是如下定义的主值积分: Hf(x)=P.V.integral -1 to 1 f(x-γ(t))dt/t,相应的极大算子定义为: Mf(x)=sup 1/h| integral O to h f(x-γ(t))dt|. 对高阶单调曲线本文证明了相应的算子M和H都是L~p(R~n)有界的,从而改进了Nestlerode的结果。 相似文献
943.
Ding Qing 《数学年刊B辑(英文版)》1994,15(1):35-42
This paper establishes a new Laplacian comparison theorem which is specially useful to the manifolds of nonpositive curvature.It leads naturally to the corresponding heat kernel comparison and eigenvalue comparison theorems. Furthermore, a lower estimate of L^2-spectrum of an n-dimensional non-compact complete Cartan-Hadamard manifold is given by (n-1)k/4,provided its Ricci curvature ≤-(n-1)k(k=const.≥0). 相似文献
944.
R S Kaushal 《Pramana》1994,42(4):315-318
The ground state of a class of potentials described byV(x)=a
20
x
2+a
1/x
2 is investigated. This potential possesses some distinct features like that of a symmetric double-well potential, and can
be used in modelling the fusion process of two identical nuclei as well. 相似文献
945.
映入E(q,p)的复合算子 总被引:3,自引:0,他引:3
§ 1 . Introduction LetD ={z:|z| <1}betheunitdiskofcomplexplane,H(D)bethespaceofallana lysticfunctionsonD ,denoteLebesguemeasureonDbydm ,normalizedsothatm(D) =1.Fora ∈D ,σa(z) =a-z1- az istheMobiustransformationofDtoitselfandg(z,a) =log|1- aza-z|istheGreenfunctionofDwithsingularityata.Everyanalyticself mapφ :D →DoftheunitdiskinducesthroughcompositionalinearcompositionoperatorCφfromH(D)toitself.Itisawell knownconsequenceofLittlewood’ssubordinationprinciple( [1],[2 ])that… 相似文献
946.
The mathematical structure of the optical cubic-quintic Schrödinger equation is investigated in a special way by considering a potential depending upon the modulus of the wave-functions involved. In this context, an associated operator is defined. 相似文献
947.
This paper is concerned with the Poincaré-Steklov operator that is widely used in domain decomposition methods. It is proved that the inverse of the Poincaré-Steklov operator can be expressed explicitly by an integral operator with a kernel being the Green's function restricted to the interface. As an application, for the discrete Poincaré-Steklov operator with respect to either a line (edge) or a star-shaped web associated with a single vertex point, a preconditioner can be constructed by first imbedding the line as the diameter of a disk, or the web as a union of radii of a disk, and then using the Green's function on the disk. The proposed technique can be effectively used in conjunction with various existing domain decomposition techniques, especially with the methods based on vertex spaces (from multi-subdomain decomposition). Some numerical results are reported.
948.
Oleg Safronov 《Journal of Mathematical Analysis and Applications》2007,326(1):192-208
For a large class of multi-dimensional Schrödinger operators it is shown that the absolutely continuous spectrum is essentially supported by [0,∞). We require slow decay and mildly oscillatory behavior of the potential in a cone and can allow for arbitrary non-negative bounded potential outside the cone. In particular, we do not require the existence of wave operators. The result and method of proof extends previous work by Laptev, Naboko and Safronov. 相似文献
949.
Chao Liu Lin Huang Dexing Feng 《Journal of Mathematical Analysis and Applications》2007,331(1):655-668
In this paper, a class of pendulum-like systems in infinite-dimensional Hilbert spaces is investigated. A frequency domain criterion guaranteeing the systems with the property of Lagrange stability is established. 相似文献
950.
È. M. Saydamatov 《Siberian Advances in Mathematics》2007,17(3):213-226
In the article we study the questions of well-posedness of general nonlocal boundary value problems for pseudodifferential equations in the Besov-type limit spaces. 相似文献