全文获取类型
收费全文 | 1557篇 |
免费 | 76篇 |
国内免费 | 15篇 |
专业分类
化学 | 1023篇 |
晶体学 | 3篇 |
力学 | 58篇 |
数学 | 249篇 |
物理学 | 315篇 |
出版年
2024年 | 2篇 |
2023年 | 23篇 |
2022年 | 61篇 |
2021年 | 82篇 |
2020年 | 48篇 |
2019年 | 47篇 |
2018年 | 23篇 |
2017年 | 30篇 |
2016年 | 90篇 |
2015年 | 56篇 |
2014年 | 64篇 |
2013年 | 75篇 |
2012年 | 94篇 |
2011年 | 110篇 |
2010年 | 65篇 |
2009年 | 66篇 |
2008年 | 82篇 |
2007年 | 69篇 |
2006年 | 93篇 |
2005年 | 88篇 |
2004年 | 69篇 |
2003年 | 49篇 |
2002年 | 49篇 |
2001年 | 27篇 |
2000年 | 18篇 |
1999年 | 14篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 18篇 |
1995年 | 11篇 |
1994年 | 11篇 |
1993年 | 10篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 8篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 9篇 |
1976年 | 1篇 |
1966年 | 1篇 |
1908年 | 2篇 |
1900年 | 1篇 |
1870年 | 1篇 |
排序方式: 共有1648条查询结果,搜索用时 15 毫秒
101.
We study in a self-consistent way the impact of the emission of bulk gravitons on the (homogeneous) cosmology of a three-brane embedded in a five-dimensional spacetime. In the low energy regime, we recover the well known result that the bulk affects the Friedmann equation only via a radiationlike term C/a(4), called dark or Weyl radiation. In the high energy regime, we find that the Weyl parameter C is no longer constant but grows rapidly. Consequently, C today is determined by the past history of the brane universe and depends on the number of relativistic degrees of freedom at the high/low energy transition. 相似文献
102.
Emilio Musso Lorenzo Nicolodi 《Abhandlungen aus dem Mathematischen Seminar der Universit?t Hamburg》1999,69(1):123-138
We study surfaces with plane lines of curvature in the framework of Laguerre geometry and provide explicit representation
formulae for these surfaces in terms of a potential function. As an application, we explicitly integrate allL- minimal surfaces with plane curvature lines.
Partially supported by MURST 40. 相似文献
103.
Lorenzo Pellerito M.Teresa Lo Giudice G.C. Stocco John D. Donaldson Susan M. Grimes Peter J. Smith 《Polyhedron》1985,4(4):747-756
The complexes R2SnCl2·(H2glygly), (H2glygly = glycylglycine) (R = Me, Bun, Octn, Ph) and RSnCl3·(H2glygly) 相似文献
104.
A new metabolite, 3,6-dimethyl-4,10-dihydroxy-2-oxaspiro[4.5]dec-7-en-1,9-dione (1a), was isolated from a strain of Mycosphaerella rosigena grown on potato-agar medium. The structure was determined on the basis of chemical and spectroscopic evidence and confirmed by X-ray analysis. 相似文献
105.
Valter Franceschini 《Journal of statistical physics》1980,22(3):397-406
For some high values of the Rayleigh numberr, the Lorenz model exhibits laminar behavior due to the presence of a stable periodic orbit. A detailed numerical study shows that, forr decreasing, the turbulent behavior is reached via an infinite sequence of bifurcations, whereas forr increasing, this is due to a collapse of the stable orbit to a hyperbolic one. The infinite sequence of bifurcations is found to be compatible with Feigenbaum's conjecture. 相似文献
106.
107.
We study the full counting statistics of electric current to several drain terminals with spin-dependent entrance conductances. We show that the statistics of charge transfers can be interpreted in terms of single electrons and spin-singlet pairs coming from the source. If the source contains transport channels of high transparency, a significant fraction of electrons comes in spin-singlet pairs. 相似文献
108.
Lorenzo?BertiniEmail author Emilio N.M.?Cirillo Enzo?Olivieri 《Communications in Mathematical Physics》2005,258(2):405-443
In this paper we develop a general theory which provides a unified treatment of two apparently different problems. The weak Gibbs property of measures arising from the application of Renormalization Group maps and the mixing properties of disordered lattice systems in the Griffiths’ phase. We suppose that the system satisfies a mixing condition in a subset of the lattice whose complement is sparse enough namely, large regions are widely separated. We then show how it is possible to construct a convergent multi-scale cluster expansion.The authors acknowledge the support of Cofinanziamento MIUR. 相似文献
109.
We show that the solutions to the non-stationary Navier–Stokes equations in
(d=2,3) which are left invariant under the action of discrete subgroups of the orthogonal group O(d) decay much faster as
than in generic case and we compute, for each subgroup, the precise decay rates in space-time of the velocity field. 相似文献
110.
Ayari A Danneau R Requardt H Ortega L Lorenzo JE Monceau P Currat R Brazovskii S Grübel G 《Physical review letters》2004,93(10):106404
Using high-resolution x-ray scattering in the presence of an applied current, we report evidence for a dynamical decoupling between the two NbSe3 charge-density waves (CDWs), Q1 (T(C1)=145 K) and Q2 (T(C2)=59 K), coexisting below T(C2). Simultaneous and oppositely directed shifts of the relevant CDW superlattice spots develop above a threshold current which we identify as the depinning threshold I(C1) for the more strongly pinned upper CDW Q1 (I(C1) approximately 10I(C2)). In contrast with shifts induced by current conversion processes, the present effect is not current polarized and is not limited to the current-contact regions. We propose a model which explains this instability through a sliding-induced charge transfer between the two electronic reservoirs corresponding to the Q1 and Q2 CDWs. 相似文献