Zobrazeno 1 - 10
of 59
pro vyhledávání: '"Goncalves, L. L."'
The one-dimensional extended isotropic XY model (s=1/2) in a transverse field with uniform long-range interactions among the \textit{z} components of the spin is considered. The model is exactly solved by introducing the gaussian and Jordan-Wigner tr
Externí odkaz:
http://arxiv.org/abs/0912.1986
Autor:
De Lima, J. P., Goncalves, L. L.
The isotropic XY model $(s=1/2)$ in a transverse field, with uniform long-range interactions among the transverse components of the spins, on the inhomogeneous periodic chain, is studied. The model, composed of $N$ segments with $n$ different exchang
Externí odkaz:
http://arxiv.org/abs/0805.1753
The static and dynamic properties of the anisotropic XY-model $(s=1/2)$ on the inhomogeneous periodic chain, composed of $N$ cells with $n$ different exchange interactions and magnetic moments, in a transverse field $h,$ are determined exactly at arb
Externí odkaz:
http://arxiv.org/abs/cond-mat/0701630
This paper presents a fractal analysis of radiographic patterns obtained from specimens with three types of inserted welding defects: lack of fusion, lack of penetration, and porosity. The study focused on patterns of carbon steel beads from radiogra
Externí odkaz:
http://arxiv.org/abs/cond-mat/0612467
In this work we apply tools developed for the study of fractal properties of time series to the problem of classifying defects in welding joints probed by ultrasonic tecniques. We employ the fractal tools in a preprocessing step, producing curves wit
Externí odkaz:
http://arxiv.org/abs/cond-mat/0612416
Autor:
de Lima, J. P., Goncalves, L. L.
The $XXZ$ model $(s = 1/2)$ in a transverse field on a double chain with a uniform long-range interaction among the $z$ components of the spins is considered. The nearest-neighbour interactions are restricted to the components in the $xy$ plane and t
Externí odkaz:
http://arxiv.org/abs/cond-mat/0610670
The static and dynamic properties of the isotropic XY-model $(s=1/2)$ on the inhomogeneous periodic chain, composed of \emph{N} segments with \emph{n} different exchange interactions and magnetic moments, in a transverse field \emph{h} are obtained e
Externí odkaz:
http://arxiv.org/abs/cond-mat/0501525
Autor:
Goncalves, L. L., Goncalves, L. B.
We present in this paper a numerical investigation of literary texts by various well-known English writers, covering the first half of the twentieth century, based upon the results obtained through corpus analysis of the texts. A fractal power law is
Externí odkaz:
http://arxiv.org/abs/cond-mat/0501361
In this paper it is presented a detailed numerical investigation of acoustic emission signals obtained from test samples of fibreglass reinforced polymeric matrix composites, when subjected to tensile and flexural tests. Various fractal indices, char
Externí odkaz:
http://arxiv.org/abs/cond-mat/0412478
The one-dimensional XXZ model (s=1/2) in a transverse field, with uniform long-range interactions among the transverse components of the spins, is studied. The model is exactly solved by introducing the Jordan-Wigner transformation and the integral G
Externí odkaz:
http://arxiv.org/abs/cond-mat/0405593