全文获取类型
收费全文 | 16170篇 |
免费 | 1204篇 |
国内免费 | 933篇 |
专业分类
化学 | 905篇 |
晶体学 | 17篇 |
力学 | 1913篇 |
综合类 | 195篇 |
数学 | 13506篇 |
物理学 | 1771篇 |
出版年
2024年 | 32篇 |
2023年 | 156篇 |
2022年 | 215篇 |
2021年 | 238篇 |
2020年 | 367篇 |
2019年 | 366篇 |
2018年 | 419篇 |
2017年 | 453篇 |
2016年 | 433篇 |
2015年 | 328篇 |
2014年 | 687篇 |
2013年 | 1265篇 |
2012年 | 739篇 |
2011年 | 848篇 |
2010年 | 749篇 |
2009年 | 1013篇 |
2008年 | 1065篇 |
2007年 | 1125篇 |
2006年 | 1018篇 |
2005年 | 785篇 |
2004年 | 683篇 |
2003年 | 754篇 |
2002年 | 644篇 |
2001年 | 479篇 |
2000年 | 498篇 |
1999年 | 466篇 |
1998年 | 420篇 |
1997年 | 375篇 |
1996年 | 286篇 |
1995年 | 225篇 |
1994年 | 163篇 |
1993年 | 147篇 |
1992年 | 138篇 |
1991年 | 114篇 |
1990年 | 89篇 |
1989年 | 42篇 |
1988年 | 43篇 |
1987年 | 48篇 |
1986年 | 50篇 |
1985年 | 61篇 |
1984年 | 67篇 |
1983年 | 31篇 |
1982年 | 37篇 |
1981年 | 31篇 |
1980年 | 24篇 |
1979年 | 26篇 |
1978年 | 21篇 |
1977年 | 16篇 |
1976年 | 14篇 |
1936年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
Giovanni Cupini Marcello Guidorzi Cristina Marcelli 《Journal of Differential Equations》2007,243(2):329-348
Classical one-dimensional, autonomous Lagrange problems are considered. In absence of any smoothness, convexity or coercivity condition on the energy density, we prove a DuBois-Reymond type necessary condition, expressed as a differential inclusion involving the subdifferential of convex analysis. As a consequence, a non-existence result is obtained. 相似文献
92.
We study problems of interpolation of positive linear operators in couples of ordered Banach spaces. From this viewpoint, we study couples of noncommutative spaces L 1, L ∞ associated with weights and traces on von Neumann algebras. 相似文献
93.
94.
D.L. Skuratov Yu.L. Ratis I.A. Selezneva J. Pérez P. Fernández de Córdoba J.F. Urchueguía 《Applied Mathematical Modelling》2007
This paper deals with modelling the workpiece temperature field produced during the grinding process. The proposed model is given in terms of a two-dimensional boundary-value problem where the interdependence among the grinding wheel, the workpiece and the coolant is described by two variable functions in the boundary condition. An explicit integral form solution is constructed using the Laplace and Fourier transforms and the Green’s function method. 相似文献
95.
96.
程建纲 《数学物理学报(A辑)》2005,25(4):482-488
该文考虑两点边值问题[1/q(t)][q(t)y′(t)]′+p(t)f(y(t))= 0,λ_1 y(α)-λ_2y′(α)=0 and y(β)=B非负解的存在性, 其中p(t)可能在t=α或t=β附近具有奇异性, f(0)≥0,
lim_(y→+∞)f(y)/y=+∞, 并且存在y>0, 使得f(y)<0. 相似文献
97.
Piotr Rybka 《Journal of Differential Equations》2002,181(2):340-366
We study the behavior of solutions of the modified Stefan problem in the plane for polygonal interfaces. We are particularly interested in a solution near a singularity of either the loss of a facet or the breaking of a facet. We establish precise regularity results if a facet disappears. We use them to establish the existence of a weak solution with singular data, i.e., when some of the zero-crystalline-curvature facets have zero length. 相似文献
98.
A. M. Chebotarev 《Mathematical Notes》2002,71(3-4):408-427
We prove that a quantum stochastic differential equation is the interaction representation of the Cauchy problem for the Schrödinger equation with Hamiltonian given by a certain operator restricted by a boundary condition. If the deficiency index of the boundary-value problem is trivial, then the corresponding quantum stochastic differential equation has a unique unitary solution. Therefore, by the deficiency index of a quantum stochastic differential equation we mean the deficiency index of the related symmetric boundary-value problem.In this paper, conditions sufficient for the essential self-adjointness of the symmetric boundary-value problem are obtained. These conditions are closely related to nonexplosion conditions for the pair of master Markov equations that we canonically assign to the quantum stochastic differential equation. 相似文献
99.
We derive a moderate deviation principle for the lower tail probabilities of the length of a longest increasing subsequence in a random permutation. It refers to the regime between the lower tail large deviation regime and the central limit regime. The present article together with the upper tail moderate deviation principle in Ref. 12 yields a complete picture for the whole moderate deviation regime. Other than in Ref. 12, we can directly apply estimates by Baik, Deift, and Johansson, who obtained a (non-standard) Central Limit Theorem for the same quantity. 相似文献
100.
In this paper, we establish the existence of upper and lower solutions for a periodic boundary value problems (PBVP for short) of impulsive differential equations. which guarantees the existence of at least one solution for the problem. As an application, these results are applied to PBVP of ODE and some examples are given to illustrate our results. 相似文献