全文获取类型
收费全文 | 9919篇 |
免费 | 472篇 |
国内免费 | 445篇 |
专业分类
化学 | 494篇 |
晶体学 | 17篇 |
力学 | 187篇 |
综合类 | 34篇 |
数学 | 8623篇 |
物理学 | 1481篇 |
出版年
2023年 | 66篇 |
2022年 | 57篇 |
2021年 | 80篇 |
2020年 | 131篇 |
2019年 | 224篇 |
2018年 | 236篇 |
2017年 | 173篇 |
2016年 | 156篇 |
2015年 | 146篇 |
2014年 | 254篇 |
2013年 | 721篇 |
2012年 | 256篇 |
2011年 | 411篇 |
2010年 | 337篇 |
2009年 | 583篇 |
2008年 | 709篇 |
2007年 | 740篇 |
2006年 | 610篇 |
2005年 | 433篇 |
2004年 | 372篇 |
2003年 | 347篇 |
2002年 | 260篇 |
2001年 | 226篇 |
2000年 | 221篇 |
1999年 | 205篇 |
1998年 | 204篇 |
1997年 | 157篇 |
1996年 | 201篇 |
1995年 | 190篇 |
1994年 | 184篇 |
1993年 | 158篇 |
1992年 | 141篇 |
1991年 | 86篇 |
1990年 | 102篇 |
1989年 | 98篇 |
1988年 | 95篇 |
1987年 | 142篇 |
1986年 | 109篇 |
1985年 | 142篇 |
1984年 | 93篇 |
1983年 | 70篇 |
1982年 | 137篇 |
1981年 | 117篇 |
1980年 | 106篇 |
1979年 | 53篇 |
1978年 | 91篇 |
1977年 | 92篇 |
1976年 | 85篇 |
1975年 | 11篇 |
1973年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
91.
We characterize boundedness, compactness and weak compactness of Volterra operators acting between different weighted Banach spaces of entire functions with sup‐norms in terms of the symbol g; thus we complement recent work by Bassallote, Contreras, Hernández‐Mancera, Martín and Paul 3 for spaces of holomorphic functions on the disc and by Constantin and Peláez 16 for reflexive weighted Fock spaces. 相似文献
92.
Let φ be a Young function, Ω be a locally compact space, and μ be a positive Radon measure on Ω. We consider a strict topology (in the sense of Sentilles‐Taylor) on the Orlicz function space and investigate various properties of this locally convex topology. We also study the Orlicz space of a locally compact group G with a left Haar measure under the strict topology and certain other natural locally convex topologies. Finally we present some results on various continuity properties of convolution operators on under the topology and other natural ones. 相似文献
93.
In this paper we consider two linear differential systems on a time scale. Both systems depend linearly on a complex spectral parameter λ. We prove that if all solutions of these two systems are square integrable with respect to a given weight matrix for one value λ0, then this property is preserved for all complex values λ. This result extends and improves the corresponding continuous time statement, which was derived by Walker (1975) for two non‐hermitian linear Hamiltonian systems, to appropriate differential systems on arbitrary time scales. The result is new even in the purely discrete case, or in the scalar time scale case, as well as when both time scale systems coincide. The latter case also generalizes a limit circle invariance criterion for symplectic systems on time scales, which was recently derived by the authors. 相似文献
94.
This paper considers the class of all mappings of the form where h and g are analytic in the unit disk U, normalized by , and such that is logharmonic with respect to an analytic self‐map a of U. A distortion estimate and the radius of starlikeness are obtained for this class. Additionally, a solution to the problem of minimizing the moments of order p over the class is found, as well as an estimate for arclength. 相似文献
95.
We present a form of the Mean Value Theorem (MVT) for a continuous function f between metric spaces, connecting it with the possibility to choose the relation of f in a homeomorphic way. We also compare our formulation of the MVT with the classic one when the metric spaces are open subsets of Banach spaces. As a consequence, we derive a version of the Mean Value Propriety for measure spaces that also possesses a compatible metric structure. 相似文献
96.
Symmetrisers and generalised solutions for strictly hyperbolic systems with singular coefficients 下载免费PDF全文
This paper is devoted to strictly hyperbolic systems and equations with non‐smooth coefficients. Below a certain level of smoothness, distributional solutions may fail to exist. We construct generalised solutions in the Colombeau algebra of generalised functions. Extending earlier results on symmetric hyperbolic systems, we introduce generalised strict hyperbolicity, construct symmetrisers, prove an appropriate Gårding inequality and establish existence, uniqueness and regularity of generalised solutions. Under additional regularity assumptions on the coefficients, when a classical solution of the Cauchy problem (or of a transmission problem in the piecewise regular case) exists, the generalised solution is shown to be associated with the classical solution (or the piecewise classical solution satisfying the appropriate transmission conditions). 相似文献
97.
The Green function for the mixed problem for the linear Stokes system in domains in the plane 下载免费PDF全文
We construct the Green function for the mixed boundary value problem for the linear Stokes system in a two‐dimensional Lipschitz domain. 相似文献
98.
Giulio Peruginelli 《代数通讯》2015,43(1):197-211
We describe an algorithm to compute the different factorizations of a given image primitive integer-valued polynomial f(X) = g(X)/d ∈ ?[X], where g ∈ ?[X] and d ∈ ? is square-free, assuming that the factorizations of g(X) in ?[X] and d in ? are known. We translate this problem into a combinatorial one. 相似文献
99.
We consider extensions of certain states. The states are defined on the systems of sets that are closed under the formation of the symmetric difference (concrete quantum logics). These systems can be viewed as certain set‐representable quantum logics enriched with the symmetric difference. We first show how the compactness argument allows us to extend states on Boolean algebras over such systems of sets. We then observe that the extensions are sometimes possible even for non‐Boolean situations. On the other hand, a difference‐closed system can be constructed such that even two‐valued states do not allow for extensions. Finally, we consider these questions in a σ‐complete setup and find a large class of such systems with rather interesting state properties. 相似文献
100.
Consider the lattice of bounded linear operators on the space of Borel measures on a Polish space. We prove that the operators which are continuous with respect to the weak topology induced by the bounded measurable functions form a sublattice that is lattice isomorphic to the space of transition kernels. As an application we present a purely analytic proof of Doob's theorem concerning stability of transition semigroups. 相似文献