全文获取类型
收费全文 | 5811篇 |
免费 | 794篇 |
国内免费 | 549篇 |
专业分类
化学 | 257篇 |
力学 | 701篇 |
综合类 | 152篇 |
数学 | 4838篇 |
物理学 | 1206篇 |
出版年
2024年 | 12篇 |
2023年 | 49篇 |
2022年 | 79篇 |
2021年 | 90篇 |
2020年 | 143篇 |
2019年 | 141篇 |
2018年 | 169篇 |
2017年 | 202篇 |
2016年 | 241篇 |
2015年 | 131篇 |
2014年 | 240篇 |
2013年 | 492篇 |
2012年 | 276篇 |
2011年 | 337篇 |
2010年 | 303篇 |
2009年 | 347篇 |
2008年 | 401篇 |
2007年 | 371篇 |
2006年 | 371篇 |
2005年 | 335篇 |
2004年 | 306篇 |
2003年 | 251篇 |
2002年 | 260篇 |
2001年 | 198篇 |
2000年 | 220篇 |
1999年 | 163篇 |
1998年 | 141篇 |
1997年 | 142篇 |
1996年 | 102篇 |
1995年 | 116篇 |
1994年 | 72篇 |
1993年 | 77篇 |
1992年 | 59篇 |
1991年 | 37篇 |
1990年 | 48篇 |
1989年 | 27篇 |
1988年 | 21篇 |
1987年 | 20篇 |
1986年 | 22篇 |
1985年 | 16篇 |
1984年 | 19篇 |
1983年 | 8篇 |
1982年 | 16篇 |
1981年 | 6篇 |
1980年 | 9篇 |
1979年 | 9篇 |
1978年 | 13篇 |
1977年 | 13篇 |
1974年 | 7篇 |
1973年 | 7篇 |
排序方式: 共有7154条查询结果,搜索用时 15 毫秒
881.
Chacha and Bensayah [Asymptotic modeling of a Coulomb frictional Signorini problem for the von Kármán plates, C. R. Mécanique 336 (2008), pp. 846–850] have studied the asymptotic modelling of Coulomb frictional unilateral contact problem between an elastic nonlinear von Kármán plate and a rigid obstacle. The main result obtained is that the leading term of the asymptotic expansion is characterized by a two-dimensional Signorini problem but without friction. In this article, we extend this study to the case of a shallow shell under generalized Marguerre-von Kármán conditions. 相似文献
882.
883.
Nguyen Ngoc Luan 《Applicable analysis》2013,92(9):1694-1704
This paper establishes several new facts on generalized polyhedral convex sets and shows how they can be used in vector optimization. Among other things, a scalarization formula for the efficient solution sets of generalized linear vector optimization problems is obtained. We also prove that the efficient solution set of a generalized linear vector optimization problem in a locally convex Hausdorff topological vector space is the union of finitely many generalized polyhedral convex sets and it is connected by line segments. 相似文献
884.
Yan Xiaoyan 《The Journal of mathematical sociology》2013,37(4):359-389
A definition of fuzzy clique in social networks is suggested which overcomes five limitations of current definitions. This definition is based on the networks in which the 0–1 strengths, the weighted strengths, and fuzzy strengths are all allowed. The fuzzy distance in such a network is defined. The node‐clique and clique‐clique coefficients are suggested. The core and the periphery of fuzzy cliques are discussed formally. A “cone like” property of the cores is discovered. The network structures are discussed using the new definition. A “no circle” property of networks is found. Basic fuzzy tools and the related algorithms are also discussed. Some examples are analyzed to demonstrate the theory. 相似文献
885.
886.
Hung-Yuan Chen 《代数通讯》2013,41(10):3709-3721
Let R be a noncommutative prime ring with extended centroid C, and let D: R → R be a nonzero generalized derivation, f(X 1,…, X t ) a nonzero polynomial in noncommutative indeterminates X 1,…, X t over C with zero constant term, and k ≥ 1 a fixed integer. In this article, D and f(X 1,…, X t ) are characterized if the Engel identity is satisfied: [D(f(x 1,…, x t )), f(x 1,…, x t )] k = 0 for all x 1,…, x t ∈ R. 相似文献
887.
Surjeet Kour 《代数通讯》2013,41(11):4100-4110
It is shown that the derivation y r ? x + (xy s + g)? y , where 0 ≤ r < s are integers, is a simple derivation of k[x, y], the polynomial ring in two variables over a field k of characteristic zero. 相似文献
888.
Masayoshi Yoshikawa 《代数通讯》2013,41(5):2046-2060
We will investigate the structure of noncommutative imprimitive association schemes of rank 6 and the representation of their adjacency algebras. From this investigation, we will construct new integral standard generalized table algebras with three parameters. These algebras are noncommutative, imprimitive, and 6-dimensional. 相似文献
889.
给出了解病态线性方程组的一种新的Jacobi迭代算法,并证明了算法的收敛性;通过具体算例说明了算法的实用性和有效性. 相似文献
890.
A new family of finite-dimensional simple modular Lie superalgebra ? is constructed based on results of Y. Z. Zhang and Q. C. Zhang [J. Algebra, 2009, 321: 3601–3619]. The simplicity and generators of ? are discussed and the derivation superalgebra of ? is characterized. Furthermore, the invariance of the nonnatural filtration of ? is determined by the method of minimal dimension of image spaces. 相似文献