全文获取类型
收费全文 | 537篇 |
免费 | 12篇 |
国内免费 | 21篇 |
专业分类
力学 | 9篇 |
数学 | 510篇 |
物理学 | 4篇 |
综合类 | 47篇 |
出版年
2024年 | 3篇 |
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 3篇 |
2020年 | 7篇 |
2019年 | 12篇 |
2018年 | 10篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 5篇 |
2014年 | 16篇 |
2013年 | 53篇 |
2012年 | 22篇 |
2011年 | 32篇 |
2010年 | 30篇 |
2009年 | 54篇 |
2008年 | 39篇 |
2007年 | 38篇 |
2006年 | 27篇 |
2005年 | 29篇 |
2004年 | 25篇 |
2003年 | 7篇 |
2002年 | 19篇 |
2001年 | 8篇 |
2000年 | 18篇 |
1999年 | 9篇 |
1998年 | 14篇 |
1997年 | 13篇 |
1996年 | 12篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1978年 | 3篇 |
排序方式: 共有570条查询结果,搜索用时 0 毫秒
471.
Peixuan Weng 《Journal of Mathematical Analysis and Applications》2008,345(1):522-534
We consider a global reaction-diffusion population model with infinite distributed delay which includes models of Nicholson's blowflies and hematopoiesis derived by Gurney, Mackey and Glass, respectively. The existence of monotone wavefronts is derived by using the abstract settings of functional differential equations and Schauder fixed point theory. 相似文献
472.
The aim of the present paper is to study the regularity properties of the solution of a backward stochastic differential equation with a monotone generator in infinite dimension. We show some applications to the nonlinear Kolmogorov equation and to stochastic optimal control. 相似文献
473.
Yulia Kempner 《Discrete Mathematics》2010,310(22):3211-3218
A function F defined on the family of all subsets of a finite ground set E is quasi-concave, if F(X∪Y)≥min{F(X),F(Y)} for all X,Y⊆E. Quasi-concave functions arise in many fields of mathematics and computer science such as social choice, graph theory, data mining, clustering and other fields. The maximization of a quasi-concave function takes, in general, exponential time. However, if a quasi-concave function is defined by an associated monotone linkage function, then it can be optimized by a greedy type algorithm in polynomial time. Recently, quasi-concave functions defined as minimum values of monotone linkage functions were considered on antimatroids, where the correspondence between quasi-concave and bottleneck functions was shown Kempner and Levit (2003) [6]. The goal of this paper is to analyze quasi-concave functions on different families of sets and to investigate their relationships with monotone linkage functions. 相似文献
474.
Árpád Baricz 《Journal of Mathematical Analysis and Applications》2010,363(1):182-1146
In this paper our aim is to show that if a probability density function is geometrically concave (convex), then the corresponding cumulative distribution function and the survival function are geometrically concave (convex) too, under some assumptions. The proofs are based on the so-called monotone form of l'Hospital's rule and permit us to extend our results to the case of the concavity (convexity) with respect to Hölder means. To illustrate the applications of the main results, we discuss in details the geometrical concavity of the probability density function, cumulative distribution function and survival function of some common continuous univariate distributions. Moreover, at the end of the paper, we present a simple alternative proof to Schweizer's problem related to the Mulholland's generalization of Minkowski's inequality. 相似文献
475.
We apply the techniques of monotone and relative rearrangements to the nonrearrangement invariant spaces Lp()(Ω) with variable exponent. In particular, we show that the maps uLp()(Ω)→k(t)u*Lp*()(0,measΩ) and uLp()(Ω)→u*Lp*()(0,measΩ) are locally -Hölderian (u* (resp. p*) is the decreasing (resp. increasing) rearrangement of u (resp. p)). The pointwise relations for the relative rearrangement are applied to derive the Sobolev embedding with eventually discontinuous exponents. 相似文献
476.
In polyhedral combinatorics one often has to analyze the facial structure of less than full dimensional polyhedra. The presence
of implicit or explicit equations in the linear system defining such a polyhedron leads to technical difficulties when analyzing
its facial structure. It is therefore customary to approach the study of such a polytopeP through the study of one of its (full dimensional) relaxations (monotonizations) known as the submissive and the dominant
ofP. Finding sufficient conditions for an inequality that induces a facet of the submissive or the dominant of a polyhedron to
also induce a facet of the polyhedron itself has been posed in the literature as an important research problem. Our paper
goes a long way towards solving this problem. We address the problem in the framework of a generalized monotonization of a
polyhedronP, g-mon(P), that subsumes both the submissive and the dominant, and give a sufficient condition for an inequality that defines a facet
of g-mon(P) to define a facet ofP. For the important cases of the traveling salesman (TS) polytope in both its symmetric and asymmetric variants, and of the
linear ordering polytope, we give sufficient conditions trivially easy to verify, for a facet of the monotone completion to
define a facet of the original polytope itself.
Research supported by grant DMI-9201340 of the National Science Foundation and contract N00014-89-J-1063 of the Office of
Naval Research.
Research supported by MURST, Italy. 相似文献
477.
Mikael Barboteu Mircea Sofonea 《Journal of Mathematical Analysis and Applications》2009,358(1):110-2991
We consider a mathematical model which describes the quasistatic process of contact between a piezoelectric body and an electrically conductive support, the so-called foundation. We model the material's behavior with a nonlinear electro-viscoelastic constitutive law; the contact is frictionless and is described with the Signorini condition and a regularized electrical conductivity condition. We derive a variational formulation for the problem and then we prove the existence of a unique weak solution to the model. The proof is based on arguments of nonlinear equations with multivalued maximal monotone operators and fixed point. Then we introduce a fully discrete scheme, based on the finite element method to approximate the spatial variable and the backward Euler scheme to discretize the time derivatives. We treat the unilateral contact conditions by using an augmented Lagrangian approach. We implement this scheme in a numerical code then we present numerical simulations in the study of two-dimensional test problems, together with various comments and interpretations. 相似文献
478.
Convergence of the variable two-step BDF time discretisation of nonlinear evolution problems governed by a monotone potential operator 总被引:1,自引:0,他引:1
Etienne Emmrich 《BIT Numerical Mathematics》2009,49(2):297-323
The initial-value problem for a first-order evolution equation is discretised in time by means of the two-step backward differentiation formula (BDF) on a variable time grid. The evolution equation is governed by a monotone and coercive potential operator. On a suitable sequence of time grids, the piecewise constant interpolation and a piecewise linear prolongation of the time discrete solution are shown to converge towards the weak solution if the ratios of adjacent step sizes are close to 1 and do not vary too much. 相似文献
479.
Stochastic evolution equations in Banach spaces with unbounded nonlinear drift and diffusion operators driven by a finite
dimensional Brownian motion are considered. Under some regularity condition assumed for the solution, the rates of convergence
of various numerical approximations are estimated under strong monotonicity and Lipschitz conditions. The abstract setting
involves general consistency conditions and is then applied to a class of quasilinear stochastic PDEs of parabolic type.
The research of the second named author is partially supported by the research project BMF2003-01345. 相似文献
480.
Manoj Changat 《Discrete Mathematics》2004,286(3):185-194
The induced path transit function J(u,v) in a graph consists of the set of all vertices lying on any induced path between the vertices u and v. A transit function J satisfies monotone axiom if x,y∈J(u,v) implies J(x,y)⊆J(u,v). A transit function J is said to satisfy the Peano axiom if, for any u,v,w∈V,x∈J(v,w), y∈J(u,x), there is a z∈J(u,v) such that y∈J(w,z). These two axioms are equivalent for the induced path transit function of a graph. Planar graphs for which the induced path transit function satisfies the monotone axiom are characterized by forbidden induced subgraphs. 相似文献