全文获取类型
收费全文 | 1317篇 |
免费 | 101篇 |
国内免费 | 210篇 |
专业分类
化学 | 23篇 |
力学 | 44篇 |
综合类 | 50篇 |
数学 | 1439篇 |
物理学 | 72篇 |
出版年
2024年 | 1篇 |
2023年 | 15篇 |
2022年 | 22篇 |
2021年 | 13篇 |
2020年 | 41篇 |
2019年 | 31篇 |
2018年 | 35篇 |
2017年 | 48篇 |
2016年 | 49篇 |
2015年 | 28篇 |
2014年 | 48篇 |
2013年 | 93篇 |
2012年 | 56篇 |
2011年 | 68篇 |
2010年 | 70篇 |
2009年 | 83篇 |
2008年 | 97篇 |
2007年 | 99篇 |
2006年 | 87篇 |
2005年 | 85篇 |
2004年 | 41篇 |
2003年 | 89篇 |
2002年 | 60篇 |
2001年 | 49篇 |
2000年 | 59篇 |
1999年 | 56篇 |
1998年 | 30篇 |
1997年 | 39篇 |
1996年 | 28篇 |
1995年 | 20篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1973年 | 1篇 |
排序方式: 共有1628条查询结果,搜索用时 398 毫秒
81.
Piotr Gwiazda 《Mathematical Methods in the Applied Sciences》2005,28(18):2201-2223
This paper concerns measure‐valued solutions for the two‐dimensional granular avalanche flow model introduced by Savage and Hutter. The system is similar to the isentropic compressible Euler equations, except for a Coulomb–Mohr friction law in the source term. We will partially follow the study of measure‐valued solutions given by DiPerna and Majda. However, due to the multi‐valued nature of the friction law, new more sensitive measures must be introduced. The main idea is to consider the class of x‐dependent maximal monotone graphs of non‐single‐valued operators and their relation with 1‐Lipschitz, Carathéodory functions. This relation allows to introduce generalized Young measures for x‐dependent maximal monotone graph. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
82.
设$\varphi$为群${\rm Aut}(N)$的同态,记$H_\varphi\times N$为群$N$借助于群$H$的半直积.设$G$为有限不可解群,本文证明: 若$G$中最高阶元素个数为40, 则$G$同构于下列群之一:(1)~$Z_{4\varphi}\times A_5$,\,${\rm ker}\varphi=Z_2$; (2)~$D_{8\varphi}\times A_5,\,{\rm ker}\varphi=Z_2\times Z_2$; (3)~$G/N=S_5$, $N=Z(G)=Z_2$; (4)~$G/N=S_5$, $N=Z_2\times Z_2,\,N\cap Z(G)=Z_2$. 相似文献
83.
求出了(n-3)-filiform李代数的极大环面,并证明了(n-3)-filiform李代数是可完备化的. 相似文献
84.
Claudia A. Sanza 《Central European Journal of Mathematics》2008,6(3):372-383
n×m-valued Łukasiewicz algebras with negation were introduced and investigated in [20, 22, 23]. These algebras constitute a
non trivial generalization of n-valued Łukasiewicz-Moisil algebras and in what follows, we shall call them n×m-valued Łukasiewicz-Moisil algebras (or LM
n×m
-algebras). In this paper, the study of this new class of algebras is continued. More precisely, a topological duality for
these algebras is described and a characterization of LM
n×m
-congruences in terms of special subsets of the associated space is shown. Besides, it is determined which of these subsets
correspond to principal congruences. In addition, it is proved that the variety of LM
n×m
-algebras is a discriminator variety and as a consequence, certain properties of the congruences are obtained. Finally, the
number of congruences of a finite LM
n×m
-algebra is computed.
相似文献
85.
In this paper, we study a second order variational problem for locally convex hypersurfaces, which is the affine invariant analogue of the classical Plateau problem for minimal surfaces. We prove existence, regularity and uniqueness results for hypersurfaces maximizing affine area under appropriate boundary conditions.
86.
非紧超凸度量空间中的一个新的极大元定理及其对抽象经济的应用 总被引:2,自引:0,他引:2
在非紧超凸度量空间中建立了一个新的极大元定理.作为应用,获得了连续选择及其不动点定理和一个Browder-Fan不动点定理.最后,新建了非紧超凸度量空间中的定性对策和抽象经济的平衡点存在定理. 相似文献
87.
Finite groups of Lie type form the greater part of known finite simple groups. An important class of subgroups of finite groups
of Lie type are so-called reductive subgroups of maximal rank. These arise naturally as Levi factors of parabolic groups and
as centralizers of semisimple elements, and also as subgroups with maximal tori. Moreover, reductive groups of maximal rank
play an important part in inductive studies of subgroup structure of finite groups of Lie type. Yet a number of vital questions
dealing in the internal structure of such subgroups are still not settled. In particular, we know which quasisimple groups
may appear as central multipliers in the semisimple part of any reductive group of maximal rank, but we do not know how normalizers
of those quasisimple groups are structured. The present paper is devoted to tackling this problem.
Supported by RFBR (grant No. 05-01-00797) and by SB RAS (Young Researchers Support grant No. 29 and Integration project No.
2006.1.2).
__________
Translated from Algebra i Logika, Vol. 47, No. 1, pp. 3–30, January–February, 2008. 相似文献
88.
The problem of the boundedness of the Riesz potential I
α
, 0 < α < n, in local Morrey-type spaces is reduced to the boundedness of the Hardy operator in weighted L
p
-spaces on the cone of non-negative non-increasing functions. This allows obtaining sufficient conditions for the boundedness
in local Morrey-type spaces for all admissible values of the parameters. Moreover, for a certain range of the parameters,
these sufficient conditions coincide with the necessary ones.
V. Guliyev’s research was partially supported by the grant of the Azerbaijan-U. S. Bilateral Grants Program II (project ANSF
Award / AZM1-3110-BA-08) and the Turkish Scientific and Technological Research Council (TUBITAK, programme 2221, no. 220.01-619-4889). 相似文献
89.
Representations of distributive semilattices in ideal lattices of various algebraic structures 总被引:2,自引:0,他引:2
We study the relationships among existing results about representations of distributive semilattices by ideals in dimension
groups, von Neumann regular rings, C*-algebras, and complemented modular lattices. We prove additional representation results
which exhibit further connections with the scattered literature on these different topics.
Received March 2, 1998; accepted in final form November 9, 2000. 相似文献
90.
Veli B. Shakhmurov 《中国科学A辑(英文版)》2008,51(7):1215-1231
The unique continuation theorems for the anisotropic partial differential-operator equations with variable coeffcients in Banach-valued Lp-spaces are studied.To obtain the uniform maximal regularity and the Carleman type estimates for parameter depended differential-operator equations,the suffcient conditions are founded.By using these facts,the unique continuation properties are established.In the application part,the unique continuation properties and Carleman estimates for finite or infinite systems of quasielliptic partial differential equations are studied. 相似文献