全文获取类型
收费全文 | 9382篇 |
免费 | 664篇 |
国内免费 | 1217篇 |
专业分类
化学 | 3257篇 |
晶体学 | 48篇 |
力学 | 184篇 |
综合类 | 148篇 |
数学 | 6226篇 |
物理学 | 1400篇 |
出版年
2024年 | 5篇 |
2023年 | 100篇 |
2022年 | 127篇 |
2021年 | 229篇 |
2020年 | 234篇 |
2019年 | 291篇 |
2018年 | 273篇 |
2017年 | 295篇 |
2016年 | 217篇 |
2015年 | 202篇 |
2014年 | 339篇 |
2013年 | 1029篇 |
2012年 | 314篇 |
2011年 | 436篇 |
2010年 | 374篇 |
2009年 | 522篇 |
2008年 | 584篇 |
2007年 | 753篇 |
2006年 | 572篇 |
2005年 | 529篇 |
2004年 | 460篇 |
2003年 | 493篇 |
2002年 | 422篇 |
2001年 | 339篇 |
2000年 | 291篇 |
1999年 | 285篇 |
1998年 | 284篇 |
1997年 | 250篇 |
1996年 | 186篇 |
1995年 | 112篇 |
1994年 | 129篇 |
1993年 | 82篇 |
1992年 | 78篇 |
1991年 | 58篇 |
1990年 | 43篇 |
1989年 | 43篇 |
1988年 | 42篇 |
1987年 | 42篇 |
1986年 | 24篇 |
1985年 | 41篇 |
1984年 | 23篇 |
1983年 | 15篇 |
1982年 | 19篇 |
1981年 | 19篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1978年 | 11篇 |
1977年 | 12篇 |
1976年 | 4篇 |
1936年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
11.
Rose Morris-Wright 《Journal of Pure and Applied Algebra》2021,225(1):106468
Parabolic subgroups are the building blocks of Artin groups. This paper extends previous results of Cumplido, Gebhardt, Gonzales-Meneses and Wiest, known only for parabolic subgroups of finite type Artin groups, to parabolic subgroups of FC-type Artin groups. We show that the class of finite type parabolic subgroups is closed under intersection. We also study an analog of the curve complex for mapping class group constructed by Cumplido et al. using parabolic subgroups. We extend the construction of this complex, called the complex of parabolic subgroups, to FC-type Artin groups. We show that this simplicial complex is, in most cases, infinite diameter and conjecture that it is δ-hyperbolic. 相似文献
12.
《Discrete Mathematics》2022,345(4):112767
Let R be a finite commutative chain ring, be the dihedral group of size 2n and be the dihedral group ring. In this paper, we completely characterize left ideals of (called left -codes) when . In this way, we explore the structure of some skew-cyclic codes of length 2 over R and also over , where S is an isomorphic copy of R. As a particular result, we give the structure of cyclic codes of length 2 over R. In the case where is a Galois field, we give a classification for left -codes over , for any positive integer N. In both cases we determine dual codes and identify self-dual ones. 相似文献
13.
《Discrete Mathematics》2022,345(10):112984
Let G be a generalized dicyclic group with identity 1. An inverse closed subset S of is called minimal if and there exists some such that . In this paper, we characterize distance-regular Cayley graphs of G under the condition that S is minimal. 相似文献
14.
15.
16.
17.
18.
19.
A novel, rational‐designed approach to access various heteroaryl‐substituted alkyl thioethers was developed via docking‐migration cascade process. By utilizing three components involving alkene, dual‐function reagent, and thioetherificating reagent, radical heteroarylalkylation of alkenes followed by thiolation of the alkyl radical intermediates proceeded smoothly, manifesting well compatibility of substrates and cascade transformations. Furthermore, this protocol also features mild conditions, broad substrate scope, and wide product diversity. 相似文献
20.
Let x=(x',x')with x'∈Rk and x'∈R^N-k andΩbe a x'-symmetric and bounded domain in R^N(N≥2).We show that if 0≤a≤k-2,then there exists a positive constant C>0 such that for all x'-symmetric function u∈C0^∞(Ω)with∫Ω|■u(x)|^N-a|x'|^-adx≤1,the following uniform inequality holds1/∫Ω|x|^-adx∫Ωe^βa|u|N-a/N-a-1|x'|^-adx≤C,whereβa=(N-a)(2πN/2Γ(k-a/2)Γ(k/2)/Γ(k/2)r(N-a/2))1/N-a-1.Furthermore,βa can not be replaced by any greater number.As the application,we obtain some weighted Trudinger–Moser inequalities for x-symmetric function on Grushin space. 相似文献