全文获取类型
收费全文 | 5560篇 |
免费 | 674篇 |
国内免费 | 637篇 |
专业分类
化学 | 3057篇 |
晶体学 | 33篇 |
力学 | 207篇 |
综合类 | 77篇 |
数学 | 2428篇 |
物理学 | 1069篇 |
出版年
2024年 | 2篇 |
2023年 | 42篇 |
2022年 | 58篇 |
2021年 | 95篇 |
2020年 | 167篇 |
2019年 | 166篇 |
2018年 | 173篇 |
2017年 | 233篇 |
2016年 | 185篇 |
2015年 | 200篇 |
2014年 | 288篇 |
2013年 | 965篇 |
2012年 | 270篇 |
2011年 | 303篇 |
2010年 | 267篇 |
2009年 | 320篇 |
2008年 | 351篇 |
2007年 | 361篇 |
2006年 | 350篇 |
2005年 | 293篇 |
2004年 | 278篇 |
2003年 | 248篇 |
2002年 | 204篇 |
2001年 | 146篇 |
2000年 | 161篇 |
1999年 | 111篇 |
1998年 | 133篇 |
1997年 | 72篇 |
1996年 | 90篇 |
1995年 | 81篇 |
1994年 | 62篇 |
1993年 | 36篇 |
1992年 | 28篇 |
1991年 | 16篇 |
1990年 | 18篇 |
1989年 | 15篇 |
1988年 | 16篇 |
1987年 | 13篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 10篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1973年 | 2篇 |
1936年 | 1篇 |
排序方式: 共有6871条查询结果,搜索用时 19 毫秒
71.
Abdollah Alhevaz 《代数通讯》2017,45(3):919-923
Ever since the introduction, skew inverse Laurent series rings have kept growing in importance, as researchers characterized their properties (such as Noetherianness, Armendarizness, McCoyness, etc.) in terms of intrinsic properties of the base ring and studied their relations with other fields of mathematics, as for example quantum mechanics theory. The goal of our paper is to study the primeness and semiprimeness of general skew inverse Laurent series rings R((x?1;σ,δ)), where R is an associative ring equipped with an automorphism σ and a σ-derivation δ. 相似文献
72.
73.
Tsiu-Kwen Lee 《代数通讯》2017,45(7):2967-2968
We give a short proof of Litoff’s theorem from the viewpoint of completely reducible modules. 相似文献
74.
Chillumuntala Jayaram 《代数通讯》2017,45(6):2394-2400
In this paper we establish some characterizations for weak π-rings. 相似文献
75.
Yeliz Kara 《代数通讯》2017,45(8):3627-3635
In this article, we focus on modules with the property that every projection invariant submodule is essential in a fully invariant direct summand. In contrast to π-extending condition, it is shown that the former property is inherited by direct summands and Morita invariant. An application of our results yields that the endomorphism ring of a free module enjoys the property. Moreover, we characterize generalized triangular matrix rings with the aforementioned property and apply to somewhat special cases. 相似文献
76.
For a torsion or torsion-free group G and a field F, we characterize the group algebra FG that is Armendariz. Armendariz property for a group ring over a general ring R is also studied and related to those of Abelian group rings and the quaternion ring over R. 相似文献
77.
We give an easier way to calculate a bijection from the set of isoclasses of tilted algebras of Dynkin type Δ to the set of configurations on the translation quiver ?Δ. 相似文献
78.
Yafit Natani 《代数通讯》2017,45(9):3872-3885
In this paper, we investigate the basis graph of the monoid algebra of a submonoid of the monoid of mappings from N = {1,…,n} to itself, defined by a nested sequence of compositions of N. Each such monoid is a left regular band (LRB), that is, a semigroup S satisfying x2 = x and xyx = xy for all x,y∈S. This class is su?ciently rich that every path algebra of an acyclic quiver can be embedded in such a monoid algebra. The multiplication in the monoid algebra has a particularly simple quasi-multiplicative form, allowing definition over the integers. Combining this with a formula for Ext-groups for LRBs due to Margolis et al. [6], we get a simple criterion for the nested composition algebras to be hereditary. 相似文献
79.
The transport dynamics in complex systems governing by anomalous diffusion modelled with Riesz fractional partial differential equations 下载免费PDF全文
Santanu Saha Ray 《Mathematical Methods in the Applied Sciences》2017,40(5):1637-1648
In this paper, numerical solutions of fractional Fokker–Planck equations with Riesz space fractional derivatives have been developed. Here, the fractional Fokker–Planck equations have been considered in a finite domain. In order to deal with the Riesz fractional derivative operator, shifted Grünwald approximation and fractional centred difference approaches have been used. The explicit finite difference method and Crank–Nicolson implicit method have been applied to obtain the numerical solutions of fractional diffusion equation and fractional Fokker–Planck equations, respectively. Numerical results are presented to demonstrate the accuracy and effectiveness of the proposed numerical solution techniques. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
80.
Hanchul PARK 《数学年刊B辑(英文版)》2017,38(6):1321-1334
This paper deals with two things.First,the cohomology of canonical extensions of real topological toric manifolds is computed when coefficient ring G is a commutative ring in which 2 is unit in G.Second,the author focuses on a specific canonical extensions called doublings and presents their various properties.They include existence of infinitely many real topological toric manifolds admitting complex structures,and a way to construct infinitely many real toric manifolds which have an odd torsion in their cohomology groups.Moreover,some questions about real topological toric manifolds related to Halperin's toral rank conjecture are presented. 相似文献