全文获取类型
收费全文 | 2156篇 |
免费 | 199篇 |
国内免费 | 246篇 |
专业分类
化学 | 157篇 |
晶体学 | 4篇 |
力学 | 147篇 |
综合类 | 62篇 |
数学 | 1607篇 |
物理学 | 624篇 |
出版年
2024年 | 7篇 |
2023年 | 34篇 |
2022年 | 30篇 |
2021年 | 48篇 |
2020年 | 70篇 |
2019年 | 58篇 |
2018年 | 43篇 |
2017年 | 49篇 |
2016年 | 69篇 |
2015年 | 59篇 |
2014年 | 126篇 |
2013年 | 124篇 |
2012年 | 81篇 |
2011年 | 102篇 |
2010年 | 113篇 |
2009年 | 119篇 |
2008年 | 138篇 |
2007年 | 166篇 |
2006年 | 132篇 |
2005年 | 116篇 |
2004年 | 107篇 |
2003年 | 112篇 |
2002年 | 116篇 |
2001年 | 81篇 |
2000年 | 78篇 |
1999年 | 89篇 |
1998年 | 65篇 |
1997年 | 66篇 |
1996年 | 47篇 |
1995年 | 28篇 |
1994年 | 35篇 |
1993年 | 20篇 |
1992年 | 11篇 |
1991年 | 13篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 4篇 |
1957年 | 1篇 |
排序方式: 共有2601条查询结果,搜索用时 0 毫秒
111.
A multidimensional advection scheme in 3D based on the use of face‐matched flux polyhedra to integrate the volume fraction evolution equation is proposed. The algorithm tends to reduce the formation of ‘over/undershoots’ by alleviating the over/underlapping of flux polyhedra, thus diminishing the need to use local redistribution algorithms. The accuracy and efficiency of the proposed advection algorithm, which are analyzed using different tests with prescribed velocity field, compare well with other multidimensional advection methods proposed recently. The algorithm is also applied, in combination with a Navier–Stokes solver, to reproduce the impact of a water droplet falling through air on a pool of deep water. The interfacial curvature is calculated using a height‐function technique with adaptive stencil adjustment, which provides improved accuracy in regions of low grid resolution. The comparison of the numerical results with experimental results shows a good degree of agreement. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
112.
We study the prolongation of semibasic projectable tangent valued k-forms on fibered manifolds with respect to a bundle functor F on local isomorphisms that is based on the flow prolongation of vector fields and uses an auxiliary linear r-th order connection on the base manifold, where r is the base order of F. We find a general condition under which the Frölicher-Nijenhuis bracket is preserved. Special attention is paid to the curvature of connections. The first order jet functor and the tangent functor are discussed in detail. Next we clarify how this prolongation procedure can be extended to arbitrary projectable tangent valued k-forms in the case F is a fiber product preserving bundle functor on the category of fibered manifolds with m-dimensional bases and local diffeomorphisms as base maps. 相似文献
113.
Takumi Yokota 《Geometriae Dedicata》2008,133(1):169-179
In this paper, we consider the behavior of the total absolute and the total curvature under the Ricci flow on complete surfaces
with bounded curvature. It is shown that they are monotone non-increasing and constant in time, respectively, if they exist
and are finite at the initial time. As a related result, we prove that the asymptotic volume ratio is constant under the Ricci
flow with non-negative Ricci curvature, at the end of the paper.
相似文献
114.
115.
Vy khoi Le 《Czechoslovak Mathematical Journal》2008,58(2):541-560
The paper is about a sub-supersolution method for the prescribed mean curvature problem. We formulate the problem as a variational
inequality and propose appropriate concepts of sub-and supersolutions for such inequality. Existence and enclosure results
for solutions and extremal solutions between sub-and supersolutions are established. 相似文献
116.
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.
117.
J. Carlos Díaz-Ramos Eduardo García-Río Luis Hervella 《Annali di Matematica Pura ed Applicata》2005,184(1):115-130
Total scalar curvatures of geodesic spheres obtained by integrating the second-order scalar invariants of the curvature tensor are investigated. The first terms in their power-series expansions are derived and these results are used to characterize the two-point homogeneous spaces among Riemannian manifolds with adapted holonomy. Dedicated to Professor L. VanheckeMathematics Subject Classification (2000) 53C25, 53C30 相似文献
118.
119.
Given a positive function F on S^n which satisfies a convexity condition, we introduce the r-th anisotropic mean curvature Mr for hypersurfaces in R^n+1 which is a generalization of the usual r-th mean curvature Hr. We get integral formulas of Minkowski type for compact hypersurfaces in R^n+1. We give some new characterizations of the Wulff shape by the use of our integral formulas of Minkowski type, in case F=1 which reduces to some well-known results. 相似文献
120.
By variational methods, for a kind of Yamabe problem whose scalar curvature vanishes in the unit ball BN and on the boundary S^N-1 the mean curvature is prescribed, we construct multi-peak solutions whose maxima are located on the boundary as the parameter tends to 0^+ under certain assumptions. We also obtain the asymptotic behaviors of the solutions. 相似文献