全文获取类型
收费全文 | 3407篇 |
免费 | 411篇 |
国内免费 | 423篇 |
专业分类
化学 | 280篇 |
晶体学 | 11篇 |
力学 | 162篇 |
综合类 | 112篇 |
数学 | 3201篇 |
物理学 | 475篇 |
出版年
2024年 | 7篇 |
2023年 | 27篇 |
2022年 | 45篇 |
2021年 | 54篇 |
2020年 | 122篇 |
2019年 | 100篇 |
2018年 | 99篇 |
2017年 | 124篇 |
2016年 | 110篇 |
2015年 | 94篇 |
2014年 | 123篇 |
2013年 | 303篇 |
2012年 | 169篇 |
2011年 | 192篇 |
2010年 | 187篇 |
2009年 | 232篇 |
2008年 | 207篇 |
2007年 | 238篇 |
2006年 | 192篇 |
2005年 | 202篇 |
2004年 | 174篇 |
2003年 | 160篇 |
2002年 | 135篇 |
2001年 | 135篇 |
2000年 | 126篇 |
1999年 | 86篇 |
1998年 | 91篇 |
1997年 | 83篇 |
1996年 | 73篇 |
1995年 | 43篇 |
1994年 | 51篇 |
1993年 | 26篇 |
1992年 | 31篇 |
1991年 | 14篇 |
1990年 | 24篇 |
1989年 | 10篇 |
1988年 | 11篇 |
1987年 | 15篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 21篇 |
1983年 | 10篇 |
1982年 | 11篇 |
1981年 | 15篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1978年 | 9篇 |
1977年 | 12篇 |
1976年 | 3篇 |
1975年 | 2篇 |
排序方式: 共有4241条查询结果,搜索用时 31 毫秒
1.
M. Amar D. Andreucci R. Gianni C. Timofte 《Journal of Mathematical Analysis and Applications》2021,493(2):124533
We prove a well-posedness result for two pseudo-parabolic problems, which can be seen as two models for the same electrical conduction phenomenon in heterogeneous media, neglecting the magnetic field. One of the problems is the concentration limit of the other one, when the thickness of the dielectric inclusions goes to zero. The concentrated problem involves a transmission condition through interfaces, which is mediated by a suitable Laplace-Beltrami type equation. 相似文献
2.
ABSTRACTThe Coupled-Cluster (CC) theory is one of the most successful high precision methods used to solve the stationary Schrödinger equation. In this article, we address the mathematical foundation of this theory with focus on the advances made in the past decade. Rather than solely relying on spectral gap assumptions (non-degeneracy of the ground state), we highlight the importance of coercivity assumptions – Gårding type inequalities – for the local uniqueness of the CC solution. Based on local strong monotonicity, different sufficient conditions for a local unique solution are suggested. One of the criteria assumes the relative smallness of the total cluster amplitudes (after possibly removing the single amplitudes) compared to the Gårding constants. In the extended CC theory the Lagrange multipliers are wave function parameters and, by means of the bivariational principle, we here derive a connection between the exact cluster amplitudes and the Lagrange multipliers. This relation might prove useful when determining the quality of a CC solution. Furthermore, the use of an Aubin–Nitsche duality type method in different CC approaches is discussed and contrasted with the bivariational principle. 相似文献
3.
AbstractRealistic stochastic modeling is increasingly requiring the use of bounded noises. In this work, properties and relationships of commonly employed bounded stochastic processes are investigated within a solid mathematical ground. Four families are object of investigation: the Sine-Wiener (SW), the Doering–Cai–Lin (DCL), the Tsallis–Stariolo–Borland (TSB), and the Kessler–Sørensen (KS) families. We address mathematical questions on existence and uniqueness of the processes defined through Stochastic Differential Equations, which often conceal non-obvious behavior, and we explore the behavior of the solutions near the boundaries of the state space. The expression of the time-dependent probability density of the Sine-Wiener noise is provided in closed form, and a close connection with the Doering–Cai–Lin noise is shown. Further relationships among the different families are explored, pathwise and in distribution. Finally, we illustrate an analogy between the Kessler–Sørensen family and Bessel processes, which allows to relate the respective local times at the boundaries. 相似文献
4.
5.
M.A. Tawhid 《Journal of Optimization Theory and Applications》2002,113(1):149-164
In this paper, we give some sufficient conditions for the local uniqueness of solutions to nonsmooth variational inequalities where the underlying functions are H-differentiable and the underlying set is a closed convex set/polyhedral set/box/polyhedral cone. We show how the solution of a linearized variational inequality is related to the solution of the variational inequality. These results extend/unify various similar results proved for C
1 and locally Lipschitzian variational inequality problems. When specialized to the nonlinear complementarity problem, our results extend/unify those of C
2 and C
1 nonlinear complementarity problems. 相似文献
6.
7.
许明浩 《武汉大学学报(理学版)》1996,(1)
讨论如下Hilbert空间中的半线性随机发展方程的Cauchy问题 dy(t)=[Ay(t) f(t,y(t))]dt G(t,y(t))dw(t) y(O)=V_u的适度解的存在唯一性,在更一般的条件下,得到了该问题的适度解的存在唯一性。 相似文献
8.
9.
10.
T-型树谱唯一性的一个简单刻画 总被引:1,自引:0,他引:1
图G称为谱唯一的,如果任何与G谱相同的图一定与G同构.一棵树称为T-型树如果其仅有一个最大度为3的顶点.本文给出了T-型树谱唯一性的一个简单刻画,从而完全解决了T-型树的谱唯一性问题. 相似文献