全文获取类型
收费全文 | 540篇 |
免费 | 14篇 |
国内免费 | 31篇 |
专业分类
化学 | 74篇 |
力学 | 51篇 |
数学 | 272篇 |
物理学 | 188篇 |
出版年
2023年 | 6篇 |
2021年 | 8篇 |
2020年 | 17篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 11篇 |
2016年 | 9篇 |
2015年 | 12篇 |
2014年 | 22篇 |
2013年 | 44篇 |
2012年 | 17篇 |
2011年 | 35篇 |
2010年 | 22篇 |
2009年 | 37篇 |
2008年 | 36篇 |
2007年 | 38篇 |
2006年 | 38篇 |
2005年 | 22篇 |
2004年 | 21篇 |
2003年 | 21篇 |
2002年 | 30篇 |
2001年 | 15篇 |
2000年 | 17篇 |
1999年 | 12篇 |
1998年 | 19篇 |
1997年 | 19篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 8篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有585条查询结果,搜索用时 212 毫秒
31.
32.
Marco Castrillón López Jaime Muñz Masquó 《International Journal of Theoretical Physics》2007,46(4):1020-1026
It is proved that the Euler–Lagrange equations of a Yang-Mills type Lagragian is independent with respect to the chosen pairing
in the Lie algebra. Moreover, the Hamilton-Cartan equations of these Lagrangians are obtained and proved to be also independent
with respect to the pairing.
PACS Numbers 2003: 02.20.Qs, 02.20.Sv, 02.20.Tw, 02.40.Ma, 02.40.Vh, 11.10.Ef, 11.15.Kc
Mathematics Subject Classification 2000: Primary 70S15, Secondary 58A20, 58E15, 58E30, 70S05, 70S10, 81T13 相似文献
33.
Daryl Geller Domenico Marinucci 《Journal of Mathematical Analysis and Applications》2011,375(2):610-630
The construction of needlet-type wavelets on sections of the spin line bundles over the sphere has been recently addressed in Geller and Marinucci (2008) [14], and Geller et al. (2008, 2009) [12] and [13]. Here we focus on an alternative proposal for needlets on this spin line bundle, in which needlet coefficients arise from the usual, rather than the spin, spherical harmonics, as in the previous constructions. We label this system mixed needlets and investigate in full their properties, including localization, the exact tight frame characterization, reconstruction formula, decomposition of functional spaces, and asymptotic uncorrelation in the stochastic case. We outline astrophysical applications. 相似文献
34.
35.
Kjetil Røysland 《Journal of Fourier Analysis and Applications》2008,14(2):267-285
We give an equivariant version of Packer and Rieffel’s theorem on sufficient conditions for the existence of orthonormal wavelets
in projective multiresolution analysis. Suppose that the scaling functions are invariant with respect to some finite group
action. We give sufficient conditions for the existence of wavelets with similar invariance.
Research supported in part by the Research Council of Norway, project number NFR 154077/420. Some of the final work was also
done with the support from the project NFR 170620/V30. 相似文献
36.
Armen Glebovich Sergeev 《中国科学A辑(英文版)》2008,51(4):695-706
We study harmonic maps from Riemann surfaces M to the loop spaces ΩG of compact Lie groups G, using the twistor approach. We conjecture that harmonic maps of the Riemann sphere ℂℙ1 into ΩG are related to Yang-Mills G-fields on ℝ4.
This work was partly supported by the RFBR (Grant Nos. 04-01-00236, 06-02-04012), by the program of Support of Scientific
Schools (Grant No. 1542.2003.1), and by the Scientific Program of RAS “Nonlinear Dynamics” 相似文献
37.
L. R. Chen 《Optics Communications》2001,190(1-6):141-145
We investigate the conversion of cross-phase modulation (XPM) to intensity distortion due to dispersion in fibre Bragg grating (FBG) filters. We find that there can be significant XPM-induced intensity distortion, especially near the edges of the filter passband where the in-band dispersion is increasingly pronounced. Since FBG filter dispersion occurs above and beyond that in standard single-mode fibre, this enhances XPM-induced intensity distortion arising from dispersion and should be accounted for in system design. 相似文献
38.
Usha N Bhosle 《Proceedings Mathematical Sciences》2001,111(3):271-291
LetG be a connected semisimple affine algebraic group defined over C. We study the relation between stable, semistable G-bundles
on a nodal curveY and representations of the fundamental group ofY. This study is done by extending the notion of (generalized) parabolic vector bundles to principal G-bundles on the desingularizationC ofY and using the correspondence between them and principal G-bundles onY. We give an isomorphism of the stack of generalized parabolic bundles onC with a quotient stack associated to loop groups. We show that if G is simple and simply connected then the Picard group of
the stack of principal G-bundles onY is isomorphic to ⊕m Z,m being the number of components ofY. 相似文献
39.
In this paper we give a vanishing result for cohomology groups of symmetric powers of the co-normal bundle of a non-degenerate
smooth subvariety X of projective space, then we use this theorem to give a Barth type vanishing theorem.
相似文献
40.
Let Y be a projective variety over a field k (of arbitrary characteristic). Assume that the normalization X of Y is such that is normal, being the algebraic closure of k. We define a notion of strong semistability for vector bundles on Y. We show that a vector bundle on Y is strongly semistable if and only if its pull back to X is strongly semistable and hence it is a tensor category. In case , we show that strongly semistable vector bundles on Y form a neutral Tannakian category. We define the holonomy group scheme of Y to be the Tannakian group scheme for this category. For a strongly semistable principal G‐bundle , we construct a holonomy group scheme. We show that if Y is an integral complex nodal curve, then the holonomy group of a strongly semistable vector bundle on Y is the Zariski closure of the (topological) fundamental group of Y. 相似文献