Open Access Published by De Gruyter Open Access

Volume 3 Issue 3

September 2005

Issue of Open Physics

Submit manuscript

Contents
Journal Overview

Open Access September 1, 2005

High-lying doubly excited states of He and H−: electron correlations and classification schemes

Spyros Themelis

Page range: 324-338

More Download PDF

Abstract

High-lying doubly excited states of He and H− are studied and energies and intrinsic characteristics of their wave-functions are reported. Results for energies of 3Po and 1D doubly excited states associated with the hydrogenic thresholds up to N = 20 are presented and compared to available data from the literature. The classification of these doubly excited states by approximate quantum numbers is reexamined.

Open Access September 1, 2005

Tunnelling time of a gaussian wave packet through two potential barriers

Vittoria Petrillo, Vladislav Olkhovsky

Page range: 339-350

More Download PDF

Abstract

The resonant and non-resonant dynamies of a Gaussian quantum wave packet travelling through a double barrier system is studied as a function of the initial characteristics of the spectrum and of the parameters of the potential. The behaviour of the tunnelling time shows that there are situations where the Hartman effect occurs, while, when the resonances are dominant, and in particular for b>π/Δk (b being the inter-barrier distance and Δk the spectrum width), the tunnelling time becomes very large and the Hartman effect does not take place.

Open Access September 1, 2005

Radiative spectra of thermal electromagnetic noise induced by planar realistic dielectrics

Illarion Dorofeyev, Harald Fuchs, Katja Sobakinskaya

Page range: 351-375

More Download PDF

Abstract

Spectral characteristics of stochastic fields and their spatial derivatives in various planar structures composed by lossy materials described by realistic dielectric functions are numerically calculated based on solutions to the problems of multipolar electromagnetic fields in a plane layered geometry. A displacement of the maximum of the spectral power densities for spatial derivatives of fluctuating fields to the high-frequency domain, a resonant increase in the density of states of the fluctuating fields at the frequencies of interface excitations and interference modes for the radiative part of the spectra, the influence of geometry on the density of states, and other peculiarities are found by numerical calculations and graphically demonstrated. Interpretations of the above effects are provided.

Open Access September 1, 2005

Hydrostatic equilibrium and Tsallis’ equilibrium for self-gravitating systems

Jiulin Du

Page range: 376-381

More Download PDF

Abstract

Self-gravitating systems are generally thought to behavior non-extensively due to the long-range nature of gravitational forces. We discuss a relation between the nonextensive parameter q of Tsallis statistics, the temperature gradient and the gravitational potential based on the equation of hydrostatic equilibrium for self-gravitating systems. It is suggested that the nonextensive parameter in Tsallis statistics has a clear physical meaning with regard to the non-isothermal nature of the systems with long-range interactions. Tsallis’ equilibrium distribution for the self-gravitating systems describes the property of hydrostatic equilibrium of the systems.

Open Access September 1, 2005

Theoretical investigation of the electronic structure of a ferroelectric SbSI cluster at a phase transition

Algirdas Audzijonis, Gediminas Gaigalas, Leonardas Žigas, Audrius Pauliukas, Raimundas Žaltauskas, Aurimas Čerškus, Jurgis Narusis

Page range: 382-394

More Download PDF

Abstract

This paper presents the theoretical investigation of energy levels of valence bands (VB) and core levels (CL) of the ferroelectric SbSl single crystals in antiferroelectric and ferroelectric phases. Since the best approximation for the deep VB levels is a calculation by the Hartree-Fock method, the molecular model of a SbSI crystal was used for calculations. This model of the crystal was also used for calculations of the total density of states. It was found that the VB and CL of this ferroelectric semiconductor are sensitive to the small lattice distortion at the phase transition, and that an average of the total density of states, when all atoms participate in oscillations of all normal modes, are more similar to the experimental X-ray photoelectron spectra (XPS). The experimental splitting of CL obtained by XPS was compared with the theoretically calculated one by two different methods. The cluster model calculations showed that the splitting of the CL in SbSI might be caused by photoelectron emission from the atoms, which have different valence state, at the surface.

Open Access September 1, 2005

Study of solid-solution hardening in binary aluminium-based alloys

Mohamed Draissia, Mohamed-Yacine Debili

Page range: 395-408

More Download PDF

Abstract

Solid-solution formation in binary aluminium-based alloys is due essentially to the combined effects of the size and valence of solvent and solute atoms, as expected by the four Hume-Rothery rules. The lattice parameter of aluminium in the solid solution of the sputtered Al−Fe films is [Al-a (Å)=4.052−6.6×10−3Y]. The increasing and decreasing evolution of the lattice parameter of copper [Cu-a (Å)=3.612+1.8×10−3Z] and aluminium [Al-a (Å)=4.048−1.6×10−3X] in the sputtered Al-1.8 to 92.5 at. % Cu films is a result of the difference in size between the aluminium and copper atoms. The low solubility of copper in aluminium (<1.8 at % Cu) is due to the valences of solvent and solute atoms in contrast with other sputtered films prepared under similar conditions, such as Al−Mg (20 at. % Mg), Al−Ti (27 at. % Ti), Al−Cr (5at. % Cr) and Al−Fe (5.5 at. % Fe) where the solubility is due to the difference in size.

Open Access September 1, 2005

Conditions for the emergence of spatially asymmetric retrieval states in an attractor neural network

Kostadin Koroutchev, Elka Korutcheva

Page range: 409-419

More Download PDF

Abstract

In this paper we show that during the retrieval process in a binary symmetric Hebb neural network, spatially localized states can be observed when the connectivity of the network is distance-dependent and a constraint on the activity of the network is imposed, which forces different levels of activity in the retrieval and learning states. This asymmetry in the activity during retrieval and learning is found to be a sufficient condition to observe spatially localized retrieval states. The result is confirmed analytically and by simulation.

Open Access September 1, 2005

A theoretical approach to local attenuation measurements of shear waves by MRE. Preliminary experimental results

Tomasz Klinkosz, Czesław Lewa, Guillaume Madelin, Eric Thiaudiere

Page range: 420-432

More Download PDF

Abstract

An essential highlight of the presented method is the employment of Magnetic Resonance Elastography (MRE) for local measurements of the attenuation of elastic shear waves introduced into a biological sample. Such a measurement can be accomplished by combining the MRE method with those methods, in which collective displacement of spins is induced by external physical factors, such as variable electric field, strong magnetic field gradient or longitudinal elastic wave. A theoretical basis of the method involving external factors and results of preliminary experiments have been presented in this paper.

Open Access September 1, 2005

Contribution of superstring Z′ boson on the polarization effects in proton proton collisions

Rasul Muradov, Azar Ahmadov

Page range: 433-455

More Download PDF

Abstract

In this work we investigate the single- and the double-spin asymmetries at the collisions of polarized protons pp → (γ *, Z 0, Z′) + X within the scope of QCD, the electroweak interaction and superstring E 6 theory. The helicity amplitude method is used. Analytical expressions for the single- and the double-spin asymmetries are obtained and their dependence on the transverse momentum of the lepton pair is investigated at the three different values of invariant masses of the lepton pair. The pure contribution coming from the superstring Z′ boson on the single- and double- spin asymmetries has been extracted. The results obtained allow investigation of the spin structure of the proton.

Open Access September 1, 2005

Structural and optical properties of WO3 electrochromic layers prepared by the sol-gel method

Abdoljavad Novinrooz, Masoomeh Sharbatdaran, Hassan Noorkojouri

Page range: 456-466

More Download PDF

Abstract

Thin layers of tungsten trioxide have been prepared from an aqueous solution of peroxotungstic acid (PTA) using the sol-gel method. Compositional, structural and optical characteristics of WO3 coated on indium tin oxide (ITO) conductive glass substrates were studied using X-ray diffractometery (XRD), cyclic voltammetery (CV), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Monoclinic and triclinic crystalline structures for thin film and powdered WO3 were confirmed by XRD analysis. SEM micrograph of annealed samples revealed micro cracks due to a decrease in density and a contraction of layers. EDX analysis showed that 1∶2 ratio of oxygen and tungsten atoms in the prepared films is obtained at heat treatment temperatures higher than 200 °C. Furthermore, the annealed samples showed very good electrochromic behavior in cyclic voltammetery studies. Refractive index “n” and extinction coefficient “k” values were found to be reduced by increasing the wavelength and decreasing the temperature.

About this journal

Get easy access to the latest Open Physics' most cited and most downloaded papers with only one click!

Table of contents 2022 & 2021

Open Physics is a peer-reviewed, open access, electronic journal devoted to the publication of fundamental research results in all fields of physics. The journal provides the readers with free, instant, and permanent access to all content worldwide; and the authors with extensive promotion of published articles, long-time preservation, language-correction services, no space constraints and immediate publication.
Open Physics is listed inter alia by Clarivate Analytics (formerly Thomson Reuters) - Current Contents/Physical, Chemical and Earth Sciences, JCR and SCIE. Our standard policy requires each paper to be reviewed by at least two Referees and the peer-review process is single-blind.

Special / Topical Issues:

Special Issue on Predicting Patern Alterations in Nature
Guest Editors:
Prof. Abdon Atangana, University of the Free State, South (Lead Guest Editor)
Prof. Dr. Emile Franc Goufo, University of South Africa
Prof. Dr Seda İğret Araz, Siirt University, Turkey

The journal publishes research and review articles, rapid and short communications, comments and replies that cover the following areas of physical sciences:

Acoustics
Astrophysics,
Atomic and Molecular Physics,
Biological and Medical Physics,
Complex Networks, Socio- and Econophysics,
Computational Physics,
Condensed Matter Physics,
Cosmology and Gravitation,
Fluid Mechanics,
Geophysics,
Nanophysics,
Optics and Lasers,
Particle and Nuclear Physics,
Plasma Physics,
Statistical and Nonlinear Physics,
Surface Physics,
Theoretical and Mathematical Physics.

Why submit and read

Open Physics is a premier source of a high quality research. All published articles are made freely and permanently accessible online.

Authors benefit from fair and constructive peer review, language-correction services and extensive promotion of each published article.
The journal uses continuous publication model - accepted manuscripts are published quickly after the acceptance.
Thanks to Open Access, all articles are freely available to everyone, without any restrictions. There are more liberal policies on copyrights (authors retain copyright) and on self-archiving (no embargo periods). The journal is archived in Portico.

For the information on Article Processing Charges please go to Supplementary Information section below and view "Article Processing Charges" document (in PDF).
Detailed information on Editorial Policy, Publication Ethics, Instructions for Authors etc. can be found below and in the Supplementary Information section.