Decoherence of spin-deformed bosonic model

The decoherence rate and some parameters affecting it are investigated for the generalized spin-boson model. We consider the spin-bosonic model when the bosonic environment is modeled by the deformed harmonic oscillators. We show that the state of the environment approaches a non-linear coherent state. Then, we obtain the decoherence rate of a two-level system which is in contact with a deformed bosonic environment which is either in thermal equilibrium or in the ground state. By using some recent realization of f$f$-deformed oscillators, we show that some physical parameters strongly affect the decoherence rate of a two-level system.     

Correlation of highly charged ion and X-ray emissions from the laser-produced plasma in the presence of non-linear phenomena

Flux of X-ray radiation emitted from the Ta plasma, produced by the fundamental (1ω) and the third harmonic (3ω) frequencies of the high-power iodine laser PALS, was studied in dependence on the laser focus position. One or two (three) maxima, corresponding to the hard or soft component of the emitted spectrum, can appear, according to the experimental conditions. These dependencies are compared with those published by other authors, and also with our results concerning the highly charged ion generation. At laser intensities above I _L～ 10¹⁴ W/cm², the participation of non-linear processes in the pre-formed plasma was confirmed.     

Applicability of the multi-hit model to calculate the track etch rate in µm-scale in CR-39 detectors

An attempt was made to test the applicability of the multi-hit model in CR-39 SSNTD etched for a few micrometers. In this work the detector response (V _t ) as a function of the particle restricted energy loss (REL) was determined from the well-known Poisson's distribution. The model can describe the function V _t (REL) for a given ion through three registration parameters (ν, C, REL _o ). The model was used to fit the experimental data of V _t vs. REL that were quoted from the literature at different REL regions. A computer algorithm was developed to calculate, numerically, these parameters from the non-linear V _t (REL) function. It was found that the multi-hit model can predict V _t for a short as well as a long REL range in CR-39, within µm-scale, with good accuracy. The ν, C and REL _o parameters that satisfy the best possible fit for such data have been obtained and their physical meaning was stated as well.     

Non-linear realizations,Goldstone bosons of broken Lorentz rotations and effective actions for p-branes

We consider the non-linear realizations of the Poincare group for p  -branes with local subgroup SO(1,p)×SO(D−(p+1))$\mathit{SO}(1,p)\times \mathit{SO}(D-(p+1))$. The Nambu–Goto p-brane action is constructed using the Maurer–Cartan forms of the unbroken translations. We perform a throughout phase space analysis of the action and show that it leads to the canonical action of a p-brane. We also construct some higher order derivative terms of the effective p-brane action using the MC forms of the broken Lorentz transformations.     

Linear Mohr-Coulomb strength parameters from the non-linear Hoek-Brown rock masses

Most conventional computer codes, design practice and standards in rock engineering are formulated in terms of a linear Mohr-Coulomb (MC) failure criterion. However, experimental data shows that the failure of almost all types of rock masses follows a modified Hoek-Brown (HB) failure criterion that is non-linear. In order to avoid the difficulty resulting from the non-linearity of the strength envelope of rock masses in calculation of bearing capacity, the equivalent MC strength parameters from the modified HB failure criterion are developed for practical use in engineering. From the results, it is found that the equivalent strength parameters depend on not only the non-linear HB failure criterion but also the surcharge load and self-weight, which is different from the published results.     

Linear transformations on codes

This paper studies and classifies linear transformations that connect Hamming distances of codes. These include irreducible linear transformations and their concatenations. Their effect on the Hamming weights of codewords is investigated. Both linear and non-linear codes over fields are considered. We construct optimal linear codes and a family of pure binary quantum codes using these transformations.     

Estimation of curl in paper using a combination of shape measurement and least-squares modelling

Curl is a quality problem that makes paper less suitable for printing. A paper sheet that has structural variations in its thickness such as gradients of fibre orientation, density and filler content, will curl and hence assume a cylindrical shape when its humidity content is changed. We propose a method to measure curl that can be used for automated analysis of the paper quality. The shape of the curled paper is measured using a stereoscopic camera system, which is capable of viewing a random pattern that is projected onto the specimen. The shape of the object is found by calculating the perspective difference in the camera set-up using digital image correlation. The quality parameters that are searched for are the magnitude of curl, which is defined as the inverse of the radius of curvature and the orientation of the curled paper. These parameters are estimated by performing a least-squares fit of a cylindrical shape to the three-dimensional measurement data. The least-squares model is non-linear and an iterative technique based on the Gauss–Newton algorithm is used.     

Universal relations for non-linear magnetoelastic solids

In the light of recent and growing interest in the applications of magneto-sensitive elastomers and the corresponding theoretical analysis of their properties, this paper is devoted to the derivation of universal relations for these materials, that is connections between the components of a stress tensor and the components of the magnetic (induction) field vector that hold independently of the choice of constitutive law within a considered class of such laws. Here, attention is focussed on isotropic magnetoelastic materials. In particular, within this framework, it is shown that in general there is only one possible universal relation for these materials, but for particular classes of constitutive laws or for special deformations there can be more than one. The theory is exemplified by application to the problem of homogeneous triaxial deformation combined with a simple shear.     

Swift-Hohenberg方程的打靶法

§ 1　IntroductionIn this paper we shall study the formation of spatially periodic patterns in extendedsystems described by Swift- Hohenberg equationut=ku - 1 +2x22 u - u3 ,k∈ R. (1.1)This equation was first proposed in 1976 by Swiftand Hohenberg[12 ] as a simple model forthe Rayleigh- B nard instability of roll waves.However,since then an effective m odel e-quation has been proved for a variety of system s in physics and mechanics.The Swift- Hohenberg equation has been studied a …     

Conjugate resonances and bifurcations in nonlinear systems under biharmonical excitation

Using a bistable oscillator described by a Duffing equation as an example, resonances caused by a biharmonical external force with two different frequencies (the so-called vibrational resonances) are considered. It is shown that, in the case of a weakly damped oscillator, these resonances are conjugate; they occur as either the low and high frequency is varied. In addition, the resonances occur as the amplitude of the high-frequency excitation is varied. It is also shown that the high-frequency action induces the change in the number of stable steady states; these bifurcations are also conjugate, and are the cause of the seeming resonance in an overdamped oscillator.