全文获取类型
收费全文 | 6706篇 |
免费 | 230篇 |
国内免费 | 60篇 |
专业分类
化学 | 5041篇 |
晶体学 | 49篇 |
力学 | 240篇 |
综合类 | 2篇 |
数学 | 899篇 |
物理学 | 765篇 |
出版年
2024年 | 14篇 |
2023年 | 68篇 |
2022年 | 347篇 |
2021年 | 349篇 |
2020年 | 228篇 |
2019年 | 264篇 |
2018年 | 236篇 |
2017年 | 182篇 |
2016年 | 336篇 |
2015年 | 230篇 |
2014年 | 246篇 |
2013年 | 597篇 |
2012年 | 420篇 |
2011年 | 463篇 |
2010年 | 274篇 |
2009年 | 233篇 |
2008年 | 320篇 |
2007年 | 303篇 |
2006年 | 256篇 |
2005年 | 226篇 |
2004年 | 195篇 |
2003年 | 159篇 |
2002年 | 170篇 |
2001年 | 64篇 |
2000年 | 70篇 |
1999年 | 49篇 |
1998年 | 34篇 |
1997年 | 47篇 |
1996年 | 43篇 |
1995年 | 38篇 |
1994年 | 40篇 |
1993年 | 33篇 |
1992年 | 36篇 |
1991年 | 31篇 |
1990年 | 46篇 |
1989年 | 27篇 |
1988年 | 23篇 |
1987年 | 29篇 |
1986年 | 27篇 |
1985年 | 36篇 |
1984年 | 23篇 |
1983年 | 19篇 |
1982年 | 25篇 |
1981年 | 22篇 |
1980年 | 14篇 |
1979年 | 17篇 |
1978年 | 12篇 |
1977年 | 14篇 |
1976年 | 11篇 |
1975年 | 7篇 |
排序方式: 共有6996条查询结果,搜索用时 15 毫秒
991.
Mohamed Bouali 《Mathematical Notes》2018,104(1-2):176-196
A β-matrix model with singular potential is described. A global asymptotic of the density of eigenvalues or the statistical density is obtained by using the equilibrium measure method. The large n-limit density of eigenvalues generalizes Wigner’s semicircle law. 相似文献
992.
993.
M. Ezzat Mohamed Mohammed M. Al-Shomrani M. I. Elashiry 《Periodica Mathematica Hungarica》2018,76(2):265-270
A subgroup H of a finite group G is quasinormal in G if it permutes with every subgroup of G. A subgroup H of a finite group G is \(\mathfrak {F}_{hq}\)-supplemented in G if G has a quasinormal subgroup N such that HN is a Hall subgroup of G and \((H\cap N)H_{G}/ H_{G} \le Z_{\mathfrak {F}}(G/H_{G})\), where \(H_{G}\) is the core of H in G and \({Z}_{\mathfrak {F}} (G/H_{G})\) is the \(\mathfrak {F}\)-hypercenter of \({G/H}_{G}\). This paper concerns the structure of a finite group G under the assumption that some subgroups of G are \(\mathfrak {F}_{hq}\)-supplemented in G. 相似文献
994.
On a resolvent approach for perturbed semigroups and application to $$L^1$$-neutron transport theory
We give new sufficient and practical conditions in terms of the generators ensuring the stability of the critical or the essential type of a perturbed \(C_0\)-semigroup in general Banach spaces. We apply our theoretical results in order to investigate the control and in particular the time asymptotic behavior of solutions to a broad class of transport equations in \(L^1\)-spaces and higher dimension. Our results improve, complete and enrich several earlier works. 相似文献
995.
Abderrahim Aslimani Imad El Ghazi Mohamed El Kadiri Sabah Haddad 《Annali dell'Universita di Ferrara》2018,64(1):25-46
We study the existence and the regularity of the biharmonic Green kernel in a Brelot biharmonic space whose associated harmonic spaces have Green kernels. We show by some examples that this kernel does not always exist. We then introduce and study the adjoint of the given biharmonic space. This study was initiated by Smyrnelis, however, it seems that several results were incomplete and we clarify them here. 相似文献
996.
997.
998.
Mohamed Bouali 《Complex Analysis and Operator Theory》2018,12(7):1707-1727
In this paper we investigate a Lévy–Khinchin type integral formula of negative definite functions defined over the Olshanski spherical pair of infinite hermitian matrices. 相似文献
999.
Mohamed Bekiri 《复变函数与椭圆型方程》2018,63(10):1421-1437
Using a variational method, we prove the existence of nodal solutions to prescribed scalar Q- curvature type equations on compact Riemannian manifolds with boundary. These equations are fourth-order elliptic equations with critical Sobolev growth. 相似文献
1000.
Jacques Carlier Mohamed Haouari Mohamed Kharbeche Aziz Moukrim 《European Journal of Operational Research》2010,202(3):859
This study investigates an optimization-based heuristic for the robotic cell problem. This problem arises in automated cells and is a complex flow shop problem with a single transportation robot and a blocking constraint. We propose an approximate decomposition algorithm. The proposed approach breaks the problem into two scheduling problems that are solved sequentially: a flow shop problem with additional constraints (blocking and transportation times) and a single machine problem with precedence constraints, time lags, and setup times. For each of these problems, we propose an exact branch-and-bound algorithm. Also, we describe a genetic algorithm that includes, as a mutation operator, a local search procedure. We report the results of a computational study that provides evidence that the proposed optimization-based approach delivers high-quality solutions and consistently outperforms the genetic algorithm. However, the genetic algorithm delivers reasonably good solutions while requiring significantly shorter CPU times. 相似文献