全文获取类型
收费全文 | 2910篇 |
免费 | 100篇 |
国内免费 | 15篇 |
专业分类
化学 | 2023篇 |
晶体学 | 13篇 |
力学 | 52篇 |
数学 | 467篇 |
物理学 | 470篇 |
出版年
2022年 | 16篇 |
2021年 | 34篇 |
2020年 | 70篇 |
2019年 | 41篇 |
2018年 | 34篇 |
2017年 | 23篇 |
2016年 | 77篇 |
2015年 | 67篇 |
2014年 | 74篇 |
2013年 | 123篇 |
2012年 | 117篇 |
2011年 | 117篇 |
2010年 | 97篇 |
2009年 | 91篇 |
2008年 | 110篇 |
2007年 | 121篇 |
2006年 | 130篇 |
2005年 | 120篇 |
2004年 | 105篇 |
2003年 | 97篇 |
2002年 | 110篇 |
2001年 | 58篇 |
2000年 | 65篇 |
1999年 | 62篇 |
1998年 | 54篇 |
1997年 | 61篇 |
1996年 | 66篇 |
1995年 | 66篇 |
1994年 | 55篇 |
1993年 | 53篇 |
1992年 | 55篇 |
1991年 | 41篇 |
1990年 | 38篇 |
1989年 | 46篇 |
1988年 | 25篇 |
1987年 | 19篇 |
1986年 | 28篇 |
1985年 | 30篇 |
1984年 | 32篇 |
1983年 | 35篇 |
1981年 | 30篇 |
1980年 | 29篇 |
1979年 | 32篇 |
1978年 | 32篇 |
1977年 | 24篇 |
1976年 | 24篇 |
1975年 | 19篇 |
1974年 | 24篇 |
1973年 | 30篇 |
1971年 | 19篇 |
排序方式: 共有3025条查询结果,搜索用时 15 毫秒
1.
In this article we introduce a natural extension of the well-studied equation for harmonic maps between Riemannian manifolds by assuming that the target manifold is equipped with a connection that is metric but has non-vanishing torsion. Such connections have already been classified in the work of Cartan(1924).The maps under consideration do not arise as critical points of an energy functional leading to interesting mathematical challenges. We will perform a first mathematical analysis of these maps which we will call harmonic maps with torsion. 相似文献
2.
Volker Elling. 《Mathematics of Computation》2006,75(256):1721-1733
A particular case of initial data for the two-dimensional Euler equations is studied numerically. The results show that the Godunov method does not always converge to the physical solution, at least not on feasible grids. Moreover, they suggest that entropy solutions (in the weak entropy inequality sense) are not well posed.
3.
Volker John 《国际流体数值方法杂志》2004,44(7):777-788
This paper presents a numerical study of a two‐dimensional time‐dependent flow around a cylinder. Its main objective is to provide accurate reference values for the maximal drag and lift coefficient at the cylinder and for the pressure difference between the front and the back of the cylinder at the final time. In addition, the accuracy of these values obtained with different time stepping schemes and different finite element methods is studied. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
4.
5.
6.
7.
8.
Mesophase behaviour of 2,5-dibenzoyloxy-p-benzoquinone derivatives and tetrahydrobenzene tetraesters
Sibylle Berg Volker Krone Helmut Ringsdorf Udo Quotschalla Helmut Paulus 《Liquid crystals》1991,9(2):151-163
The synthesis of 2,5-dibenzoyloxy-p-benzoquinone derivatives, their products after reduction and tetraesters from tetrahydroxybenzene prepared from those products is described. Their phase behaviour was investigated by differential scanning calorimetry and polarizing microscopy and is discussed in terms of their detailed structure. 相似文献
9.
In this article we prove a local existence and uniqueness theorem for the Kadomtsev-Petviashvili Equation (u
t
+u
xxx
+uu
x
)
x
−u
yy
=0) in the Sobolev spaces of orders≥3, with initial values in the same spaces, and periodic boundary conditions. This theorem improves previous results based
upon the application of singular perturbation techniques. 相似文献
10.