全文获取类型
收费全文 | 546篇 |
免费 | 48篇 |
国内免费 | 58篇 |
专业分类
化学 | 13篇 |
力学 | 8篇 |
综合类 | 33篇 |
数学 | 526篇 |
物理学 | 72篇 |
出版年
2023年 | 11篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 11篇 |
2019年 | 10篇 |
2018年 | 13篇 |
2017年 | 11篇 |
2016年 | 10篇 |
2015年 | 10篇 |
2014年 | 15篇 |
2013年 | 25篇 |
2012年 | 14篇 |
2011年 | 16篇 |
2010年 | 11篇 |
2009年 | 27篇 |
2008年 | 51篇 |
2007年 | 37篇 |
2006年 | 40篇 |
2005年 | 38篇 |
2004年 | 33篇 |
2003年 | 32篇 |
2002年 | 32篇 |
2001年 | 14篇 |
2000年 | 31篇 |
1999年 | 27篇 |
1998年 | 32篇 |
1997年 | 21篇 |
1996年 | 20篇 |
1995年 | 14篇 |
1994年 | 11篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有652条查询结果,搜索用时 15 毫秒
11.
P. Danchev 《Lithuanian Mathematical Journal》2007,47(2):129-134
We prove the following theorem: Any abelian p-group is an n-Σ-group which is a strong ω-elongation of a totally projective group by a p
ω+n
-projective group precisely when it is totally projective. In particular, each p-torsion p
ω+n
-projective n-Σ-group is a direct sum of countable p-groups of length not exceeding ω + n and vice versa. These two claims generalize our recent results in [6] and [7].
Published in Lietuvos Matematikos Rinkinys, Vol. 47, No. 2, pp. 155–162, April–June, 2007. 相似文献
12.
J. M. Speight 《Theoretical and Mathematical Physics》2007,152(1):1043-1055
We study the dynamics of magnetic bubble solitons in a two-dimensional isotropic antiferromagnetic spin lattice in the case
where the exchange integral J(x, y) is position dependent. In the near-continuum regime, this system is described by the relativistic
O(3) sigma model on a space-time with a spatially inhomogeneous metric determined by J. We use the geodesic approximation
to describe the low-energy soliton dynamics in this system: the n-soliton motion is approximated by geodesic motion in the
moduli space M
n
of static n-solitons equipped with the L
2 metric γ. We obtain explicit formulas for γ for various natural choices of J(x, y). Based on these, we show that single soliton
trajectories are refracted with J−1 being analogous to the refractive index and that this refraction effect allows constructing simple bubble lenses and bubble
guides. We consider the case where J has a disk inhomogeneity (with the value J
+ outside a disk and J
− < J
+ inside) in detail. We argue that for sufficiently large J
+/J
−, this type of antiferromagnet supports approximate quasibreathers: two or more coincident bubbles confined within the disk
spin internally while their shape oscillates with a generically incommensurate period.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 152, No. 1, pp. 191–208, July, 2007. 相似文献
13.
毛小兵 《南昌大学学报(理科版)》2003,27(1):23-25
对局部对称共形平坦黎曼流形中具有平坦法丛的极小子流形作了一些讨论,得到了极小子流形是全测地的两个充分条件。 相似文献
14.
Most operational models in atmospheric physics, meteorology and climatology nowadays adopt spherical geodesic grids and require “ad hoc” developed interpolation procedures. The author does a comparison between chosen representatives of linear, distance-based and cubic interpolation schemes outlining their advantages and drawbacks in this specific application field. Numerical experiments on a standard test problem, while confirming a good performance of linear and distance-based schemes in a single interpolation step, also show their minor accuracy with respect to the cubic scheme in the more realistic simulation of advection of a meteorological field. 相似文献
15.
Manuel Fernández-López Eduardo García-Río Demir N. Kupeli 《Annals of Global Analysis and Geometry》2002,21(1):1-13
A characterization of time functions on a spacetime is made by using theMöbius equation. It is shown that a time function characterized in this wayyields past timelike geodesic incompleteness and local Lorentzian warpedproduct decomposition of spacetime, provided that the stress-energy tensoris a fluid. Also, by imposing additional assumptions on the stress-energytensor and global analytic structure of the spacetime, more restrictivedecompositions closer to Robertson–Walker spacetimes are obtained. 相似文献
16.
TheImprovementofFischer'sInequalityandHadamard'sInequalityHuangLiping(黄礼平)(DepartmentofBasicSciences,XiangtanMiningInstitute,... 相似文献
17.
18.
A. Nowakowski 《Journal of Optimization Theory and Applications》1986,50(1):129-147
In this paper, on the basis of Young's method (Ref. 1), sufficient conditions for a strong relative minimum in an optimal control problem are given. Young's method generalizes geodesic coverings and the simplest Hilbert integral from the standard variational calculus. This paper carries Young's method over to nonparametric problems. 相似文献
19.
Friedbert Prü fer Franco Tricerri Lieven Vanhecke 《Transactions of the American Mathematical Society》1996,348(11):4643-4652
We first prove that a Riemannian manifold with globally constant additive Weyl invariants is locally homogeneous. Then we use this result to show that a manifold whose Laplacian commutes with all invariant differential operators is a locally homogeneous space.
20.
《复变函数与椭圆型方程》2012,57(12):1071-1075
We show in this article that there exists conjugate points at infinity in infinite dimensional Teichmüller spaces. 相似文献