全文获取类型
收费全文 | 3642篇 |
免费 | 143篇 |
国内免费 | 134篇 |
专业分类
化学 | 99篇 |
力学 | 197篇 |
综合类 | 3篇 |
数学 | 3139篇 |
物理学 | 481篇 |
出版年
2025年 | 10篇 |
2024年 | 25篇 |
2023年 | 47篇 |
2022年 | 49篇 |
2021年 | 44篇 |
2020年 | 74篇 |
2019年 | 107篇 |
2018年 | 78篇 |
2017年 | 74篇 |
2016年 | 53篇 |
2015年 | 66篇 |
2014年 | 174篇 |
2013年 | 393篇 |
2012年 | 226篇 |
2011年 | 245篇 |
2010年 | 195篇 |
2009年 | 325篇 |
2008年 | 293篇 |
2007年 | 240篇 |
2006年 | 180篇 |
2005年 | 124篇 |
2004年 | 118篇 |
2003年 | 125篇 |
2002年 | 74篇 |
2001年 | 63篇 |
2000年 | 58篇 |
1999年 | 60篇 |
1998年 | 56篇 |
1997年 | 61篇 |
1996年 | 57篇 |
1995年 | 38篇 |
1994年 | 44篇 |
1993年 | 19篇 |
1992年 | 21篇 |
1991年 | 11篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1986年 | 6篇 |
1985年 | 15篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 11篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1973年 | 3篇 |
排序方式: 共有3919条查询结果,搜索用时 0 毫秒
71.
Symmetry of graphs has been extensively studied over the past fifty years by using automorphisms of graphs and group theory which have played and still play an important role for graph theory, and promising and interesting results have been obtained, see for examples, [L.W. Beineke, R.J. Wilson, Topics in Algebraic Graph Theory, Cambridge University Press, London, 2004; N. Biggs, Algebraic Graph Theory, Cambridge University Press, London, 1993; C. Godsil, C. Royle, Algebraic graph theory, Springer-Verlag, London, 2001; G. Hahn, G. Sabidussi, Graph Symmetry: Algebraic Methods and Application, in: NATO ASI Series C, vol. 497, Kluwer Academic Publishers, Dordrecht, 1997]. We introduced generalized symmetry of graphs and investigated it by using endomorphisms of graphs and semigroup theory. In this paper, we will survey some results we have achieved in recent years. The paper consists of the following sections.
- 1. Introduction
- 2. End-regular graphs
- 3. End-transitive graphs
- 4. Unretractive graphs
- 5. Graphs and their endomorphism monoids.
Keywords: Graph; Endomorphism; Monoid; Generalized symmetry; End-regular; End-transitive; Unretractive 相似文献
72.
Boris S. Mordukhovich Nguyen Mau Nam 《Journal of Mathematical Analysis and Applications》2009,350(2):663-679
This paper is devoted to the development of variational analysis and generalized differentiation in the framework of Asplund spaces. We mainly concern the study of a special class of set-valued mapping given in the form where both F and Q are set-valued mappings between Asplund spaces. Models of this type are associated with solutions maps to the so-called (extended) generalized equations and play a significant role in many aspects of variational analysis and its applications to optimization, stability, control theory, etc. In this paper we conduct a local variational analysis of such extended solution maps S and their remarkable specifications based on dual-space generalized differential constructions of the coderivative type. The major part of our analysis revolves around coderivative calculus largely developed and implemented in this paper and then applied to establishing verifiable conditions for robust Lipschitzian stability of extended generalized equations and related objects. 相似文献
73.
A general design for the relaxed proximal point algorithm using the notion of A-maximal-relaxed accretiveness is developed, and then the convergence analysis for this algorithm in the context of solving a general class of nonlinear inclusion problems is examined along with some other results of interest involving A-maximal-relaxed accretive mappings in a real Banach space setting. 相似文献
74.
75.
In this paper, we are concerned with epiconvergent sequences of nonsmooth functions. From a general principle of upper set
convergence of set-valued maps we derive stability results for various objects in generalized differentiability. In particular,
we establish stability results for the Clarke generalized gradient of locally Lipschitz functions, respectively for the generalized
Hessian of C
1,1 functions.
相似文献
76.
一种新型的N部件串联可修系统及其可靠性分析 总被引:4,自引:0,他引:4
本文研究一种Ⅳ部件串联可修系统的一个新模型,该模型在经典。部件串联可修系统中引入了修理工可多重延误休假的概念,并且考虑了修理工使用修理设备在修理失效部件过程中可能因修理设备失效而立即更换修理设备对整个系统可靠性造成的影响,假定修理工的延误休假时间、部件的寿命和修理设备的寿命均服从指数分布,部件的修理时间、修理设备的更换时间和修理工的休假时间均服从一般连续型分布,通过使用补充变量法和广义马尔可夫过程方法得到了系统和修理设备的一些重要可靠性指标. 相似文献
77.
Generalized convexity and inequalities 总被引:1,自引:0,他引:1
G.D. Anderson M.K. Vamanamurthy M. Vuorinen 《Journal of Mathematical Analysis and Applications》2007,335(2):1294-1308
Let R+=(0,∞) and let M be the family of all mean values of two numbers in R+ (some examples are the arithmetic, geometric, and harmonic means). Given m1,m2∈M, we say that a function is (m1,m2)-convex if f(m1(x,y))?m2(f(x),f(y)) for all x,y∈R+. The usual convexity is the special case when both mean values are arithmetic means. We study the dependence of (m1,m2)-convexity on m1 and m2 and give sufficient conditions for (m1,m2)-convexity of functions defined by Maclaurin series. The criteria involve the Maclaurin coefficients. Our results yield a class of new inequalities for several special functions such as the Gaussian hypergeometric function and a generalized Bessel function. 相似文献
78.
79.
本文给出一类E-Vandermonde矩阵和广义E-Vandermonde矩阵可逆的条件及逆的矩阵表达式,并给出了求逆的迭代公式. 相似文献
80.
1.IntroductionThetwcawayerrorcomponentregressionmodelmsybeexpressedasif=o
相似文献