全文获取类型
收费全文 | 1523篇 |
免费 | 177篇 |
国内免费 | 212篇 |
专业分类
化学 | 44篇 |
晶体学 | 1篇 |
力学 | 75篇 |
综合类 | 40篇 |
数学 | 1528篇 |
物理学 | 224篇 |
出版年
2024年 | 4篇 |
2023年 | 12篇 |
2022年 | 12篇 |
2021年 | 19篇 |
2020年 | 43篇 |
2019年 | 39篇 |
2018年 | 52篇 |
2017年 | 65篇 |
2016年 | 31篇 |
2015年 | 34篇 |
2014年 | 49篇 |
2013年 | 292篇 |
2012年 | 53篇 |
2011年 | 73篇 |
2010年 | 49篇 |
2009年 | 77篇 |
2008年 | 83篇 |
2007年 | 94篇 |
2006年 | 81篇 |
2005年 | 88篇 |
2004年 | 70篇 |
2003年 | 77篇 |
2002年 | 64篇 |
2001年 | 62篇 |
2000年 | 72篇 |
1999年 | 54篇 |
1998年 | 56篇 |
1997年 | 40篇 |
1996年 | 33篇 |
1995年 | 28篇 |
1994年 | 21篇 |
1993年 | 18篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1974年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有1912条查询结果,搜索用时 31 毫秒
61.
用 732型强酸性阳离子交换树脂分离富集 ,并与改进的流动注射 (双流路 )相结合 ,建立了新型、高效的流动注射 -阳离子交换预富集 - ICP- AES在线分析体系。研究了酸度、流速、淋洗剂浓度等的选择、共存离子的干扰情况并应用于矿样的分析。 Ca,Mg,Al,Fe各元素的检出限分别为 0 .9μg/ L,0 .6 μg/ L,5.5μg/ L,1 .4μg/ L;1 0次测量的相对标准偏差分别为 3.4 4% ,1 .53% ,1 .6 0 % ,2 .58%。回收率在 93.0 %~ 1 0 1 .4 %之间。分析速度可达每小时 4 0个样品。 相似文献
62.
Abstract: We consider an approximation problem related to strongly irreducible operators, that is, does the direct sum of a strongly irreducible operator in B∞(Ω) and certain operator have a small compact perturbation which is a strongly irreducible operator in B∞(Ω)? In this paper, we prove that the direct sum of any strongly irreducible operator in B∞(Ω) and certain biquasitriangular operator have small compact perturbations which are strongly irreducible operators in B∞(Ω). 相似文献
63.
Under the conditions of a strong Coulomb repulsion between electrons at a lattice site, we now study the equations for the
self-energy part of the electron Green’s function, which we previously obtained using the generating functional method. These
equations have a form close to that corresponding to the self-consistent Born approximation in the weak-coupling theory. In
these equations, we omit the dependence of the self-energy on the momentum, which corresponds to the infinite-dimensional
space limit. We then numerically solve the integral equations, where all the variables depend only on the frequency, and obtain
results consistent with the dynamical mean field theory. In particular, we show that as the Coulomb repulsion increases, the
three-peak structure of the quasiparticle spectrum changes into a two-peak structure and the metal–insulator phase transition
occurs. The proposed method can be used to study other models of the theory of strongly correlated systems.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 154, No. 1, pp. 63–76, January, 2008. 相似文献
64.
证明存在Hammock位于有限表示型代数A上BB-倾斜模T_A诱导的AR-箭图上和代数B=End(T_A)的AR-箭图上,并用Hammock对BB-倾斜模T_A进行刻画. 相似文献
65.
The paper is devoted to a careful analysis of the shape-preserving properties of the strongly continuous semigroup generated
by a particular second-order differential operator, with particular emphasis on the preservation of higher order convexity
and Lipschitz classes. In addition, the asymptotic behaviour of the semigroup is investigated as well. The operator considered
is of interest, since it is a unidimensional Black-Scholes operator so that our results provide qualitative information on
the solutions of classical problems in option pricing theory in Mathematical Finance.
The paper is dedicated to Professor Luigi Albano on the occasion of his 70th birthday. 相似文献
66.
Xin Tang 《Frontiers of Mathematics in China》2008,3(3):371-397
In this paper, we construct families of irreducible representations for a class of quantum groups U
q
(ƒ
m
(K)). First, we give a natural construction of irreducible weight representations for U
q
(ƒ
m
(K)) using methods in spectral theory developed by Rosenberg. Second, we study the Whittaker model for the center of U
q
(ƒ
m
(K)). As a result, the structure of Whittaker representations is determined, and all irreducible Whittaker representations are
explicitly constructed. Finally, we prove that the annihilator of a Whittaker representation is centrally generated.
相似文献
67.
We discuss the existence of tilting modules which are direct limits of finitely generated tilting modules over tilted algebras.
相似文献
68.
令T是以{Wk}∞k=1B(Cn)为权序列的内射算子权移位.设T是强不可约的,而且sup1k<∞‖W-1k‖< ∞.用A′(T)表示T的换位代数,radA′(T)表示A′(T)的Jacobson根.本文刻划了radA′(T)并且证明了商代数A′(T)/radA′(T)是交换的. 相似文献
69.
70.
刻划了赋序列范数的矢值B anach序列空间ss(E)的强暴露性和暴露性,给出了它们的判据. 相似文献