全文获取类型
收费全文 | 772篇 |
免费 | 46篇 |
国内免费 | 102篇 |
专业分类
化学 | 138篇 |
晶体学 | 6篇 |
综合类 | 1篇 |
数学 | 511篇 |
物理学 | 222篇 |
综合类 | 42篇 |
出版年
2024年 | 4篇 |
2023年 | 12篇 |
2022年 | 11篇 |
2021年 | 15篇 |
2020年 | 15篇 |
2019年 | 26篇 |
2018年 | 17篇 |
2017年 | 12篇 |
2016年 | 15篇 |
2015年 | 17篇 |
2014年 | 19篇 |
2013年 | 32篇 |
2012年 | 21篇 |
2011年 | 45篇 |
2010年 | 21篇 |
2009年 | 59篇 |
2008年 | 80篇 |
2007年 | 60篇 |
2006年 | 66篇 |
2005年 | 42篇 |
2004年 | 41篇 |
2003年 | 26篇 |
2002年 | 34篇 |
2001年 | 37篇 |
2000年 | 20篇 |
1999年 | 24篇 |
1998年 | 20篇 |
1997年 | 13篇 |
1996年 | 24篇 |
1995年 | 16篇 |
1994年 | 11篇 |
1993年 | 13篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有920条查询结果,搜索用时 15 毫秒
101.
102.
We introduce the notion of internal fundamental sequence and prove that any shape morphism from an arbitrary compactum X to an internally movable compactum Y is induced by an internal fundamental sequence. We use this special kind of fundamental sequences to give characterizations and some properties of AANRC-sets and AANRN-sets. The paper ends with a section devoted to internal FANR's. 相似文献
103.
We present a systematic characterization of the domain of a generator of a one parameter group on certain C∗-subalgebras of via finite-dimensional estimates. Our approach yields an example of a densely defined closed symmetric derivation on a C∗-subalgebras of whose domain is not closed with respect to the C1-functional calculus. This completes and complements the earlier example of McIntosh (J. Funct. Anal. 30 (1977) 264). Our methods are partly based on the theory of adjoint C0-semigroups. 相似文献
104.
We study Riesz transforms associated with a sublaplacian H on a solvable Lie group G, where G has polynomial volume growth. It is known that the standard second order Riesz transforms corresponding to H are generally unbounded in Lp(G). In this paper, we establish boundedness in Lp for modified second order Riesz transforms, which are defined using derivatives on a nilpotent group GN associated with G. Our method utilizes a new algebraic approach which associates a distinguished choice of Cartan subalgebra with the sublaplacian
H. We also obtain estimates for higher derivatives of the heat kernel of H, and give a new proof (without the use of homogenization theory) of the boundedness of first order Riesz transforms. Our
results can be generalized to an arbitrary (possibly non-solvable) Lie group of polynomial growth. 相似文献
105.
A. Guichardet 《Journal of multivariate analysis》1976,6(1):138-158
The following is an expository paper, containing few and sometimes incomplete proofs, on continuous tensor products of Hilbert spaces and of group representations, and on the irreducibility of the latter; the principal results in the last direction are due to Verchik, Gelfand, and Graiev. The theory of continuous tensor products of Hilbert spaces, based on a fundamental theorem of Araki and Woods, is closely related to that of conditionally positive definite functions; it relies on the technique of symmetric Hilbert spaces, which also can be used to give a new proof of the classical Lévy-Khinchin formula (see A. Guichardet, (1973). J. Multiv.3 249–261.). Another basic tool for what follows is the 1-cohomology of unitary representations of locally compact groups; here, the main results are due to P. Delorme; let us mention, for instance, his results for the case of a group G containing a compact subgroup K such that is commutative, using a Lévy-Khinchin's type formula for K-invariant functions due to Gangolli, Faraut, and Harzallah. We add that the results exposed in that paper should have interesting connections with the central limit theorems à la Parthasarathy-Schmidt (see K. Parthasarathy, (1974). J. Multiv. Anal.4 123–149). 相似文献
106.
First-order regularity of convex functions on Carnot Groups 总被引:1,自引:0,他引:1
Matthieu Rickly 《Journal of Geometric Analysis》2006,16(4):679-702
We prove that h-convex functions on Carnot groups of step two are locally Lipschitz continuous with respect to any intrinsic
metric. We show that an additional measurability condition implies the local Lipschitz continuity of h-convex functions on
arbitrary Carnot groups.
To the Memory of Q. G. 相似文献
107.
Xiang Ma 《manuscripta mathematica》2006,120(2):163-179
Using moving frame method, we study the Möbius geometry of a pair of conformally immersed surfaces in
. Two new invariants θ and ρ associated with them arise naturally as well as the notion of touch and co-touch. As an application, adjoint transform is defined for any Willmore surface in
. It always exists locally, hence generalizes known duality theorems of Willmore surfaces. Finally we characterize a pair of adjoint Willmore surfaces in terms of harmonic map. 相似文献
108.
Malliavin's celebrated theorem on the failure of spectral synthesis for the Fourier algebra A(G) on nondiscrete abelian groups was strengthened to give failure of weak synthesis by Parthasarathy and Varma. We extend this to nonabelian groups by proving that weak synthesis holds for A(G) if and only if G is discrete. We give the injection theorem and the inverse projection theorem for weak X-spectral synthesis, as well as a condition for the union of two weak X-spectral sets to be weak X-spectral for an A(G)-submodule X of VN(G). Relations between weak X-synthesis in A(G) and A(G×G) and the Varopoulos algebra V(G) are explored. The concept of operator synthesis was introduced by Arveson. We extend several recent investigations on operator synthesis by defining and studying, for a V∞(G)-submodule M of B(L2(G)), sets of weak M-operator synthesis. Relations between X-Ditkin sets and M-operator Ditkin sets and between weak X-spectral synthesis and weak M-operator synthesis are explored. 相似文献
109.
We present a new construction of finite Gelfand pairs by looking at the action of the full automorphism group of a finite spherically homogeneous rooted tree of type r on the variety V(r,s) of all spherically homogeneous subtrees of type s.This generalizes well-known examples as the finite ultrametric space, the Hamming scheme and the Johnson scheme.We also present further generalizations of these classical examples. The first two are based on Harary's notions of composition and exponentiation of group actions. Finally, the generalized Johnson scheme provides the inductive step for the harmonic analysis of our main construction. 相似文献
110.
Nicholas J. Kuhn 《Advances in Mathematics》2006,201(2):318-378
Let K(n) be the nth Morava K-theory at a prime p, and let T(n) be the telescope of a vn-self map of a finite complex of type n. In this paper we study the K(n)*-homology of Ω∞X, the 0th space of a spectrum X, and many related matters.We give a sampling of our results.Let PX be the free commutative S-algebra generated by X: it is weakly equivalent to the wedge of all the extended powers of X. We construct a natural map
sn(X):LT(n)P(X)→LT(n)Σ∞(Ω∞X)+ 相似文献