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Volume 61 Issue 9

Issue of Zeitschrift für Naturforschung A

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Open Access June 2, 2014

Variable Separation Solutions for the (2+1)-Dimensional Breaking Soliton Equation

Ya-Hong Hu, Jia-Cheng Lan, Zheng-Yi Ma

Page range: 423-429

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Abstract

With the variable separation approach and based on the general reduction theory, we successfully obtain the variable separation solutions for the (2+1)-dimensional breaking soliton equation using of the projective Riccati equation. Based on one of the variable separation solutions and by selecting appropriate functions, a new type of interaction between the multi-valued and the single-valued solitons, that is a compacton-like semi-foldon and a 4-compacton, is investigated.

Open Access June 2, 2014

New Travelling Wave Solutions for an Asymmetric Model of a Rod in a Lattice Fluid with Nonlinear Advection

Sayed A. Elwakil, Mohsen A. Zahran, Refaat Sabry, Emad K. El-Shewy

Page range: 430-438

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Abstract

Based on the modified extended tanh-function method, we consider the continuum problem of the driven diffusive flow of particles behind an impenetrable obstacle (rod) of the length L. The results show that the presence of an obstacle, whether stationary or moving, in a driven diffusive flow with nonlinear drift will distort the local concentration profile to a state which divided the (x,y)-plane into two regions. The concentration is relatively higher in one side than the other side, apart from the value of , where D is the diffusion coefficient and v is the drift velocity. This problem has relevance for the size segregation of particulate matter which results from the relative motion of different-size paricles induced by shaking. The obtained soultions include soliton, periodical, rational and singular solutions.

Open Access June 2, 2014

Change of Electroweak Nuclear Reaction Rates by CP- and Isospin Symmetry Breaking – A Model Calculation

Harald Stumpf

Page range: 439-456

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Abstract

Based on the assumption that electroweak bosons, leptons and quarks possess a substructure of elementary fermionic constituents, in previous papers the effect of CP-symmetry breaking on the effective dynamics of these particles was calculated. Motivated by the phenomenological procedure in this paper, isospin symmetry breaking will be added and the physical consequences of these calculations will be discussed. The dynamical law of the fermionic constituents is given by a relativistically invariant nonlinear spinor field equation with local interaction, canonical quantization, selfregularization and probability interpretation. The corresponding effective dynamics is derived by algebraic weak mapping theorems. In contrast to the commonly applied modifications of the quark mass matrices, CP-symmetry breaking is introduced into this algebraic formalism by an inequivalent vacuum with respect to the CP-invariant case, represented by a modified spinor field propagator. This leads to an extension of the standard model as effective theory which contains besides the “electric” electroweak bosons additional “magnetic” electroweak bosons and corresponding interactions. If furthermore the isospin invariance of the propagator is broken too, it will be demonstrated in detail that in combination with CP-symmetry breaking this induces a considerable modification of electroweak nuclear reaction rates.

Open Access June 2, 2014

On a Generating Function and its Probability Distributions. A Contribution to the Theory of Transition Rates I

Hans Kupka

Page range: 457-468

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Abstract

A function of two complex variables with two real parameters a and b is described, which generates a sequence of probability distributions of two integer variables m ≥ 0 and n ≥ 0. Closed expressions for the special b = 0 and general case b≠ 0 and recurrence equations for calculating the probability distributions are derived. The probability distribution for m = 0 and a large enough is qualitatively bell-shaped, and that for m ≠ 0 has multiple peak structures. In both cases, the b parameter influences solely the skewness of the curves. For small a values, the distributions fall rapidly from a value of nearly one, decreasing by a factor of 10 10 or more as n increases from zero to n = 10. The influence of the b parameter on their properties can be pronounced. Finally, we note an important property of the distributions when two or several of them are convoluted with one another. The result is expressed in terms of an addition theorem in respect to the parameter a and describes a multidimensional distribution.

Open Access June 2, 2014

On a Generating Function and its Probability Distributions. A Contribution to the Theory of Transition Rates II

Hans Kupka

Page range: 469-485

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Abstract

A previous theory of integer-valued probability distributions is extended to many dimensions, to develop a really systematic way of treating mode mixing. The mixing of the vibrational components arises through the rotation of the normal coordinates and consequently by mixing of the parameter components in consequence of a linear relationship. The multidimensional distribution (MD), is derived with the aid of a 2N-dimensional generating function (GF), which is holomorphic in a polydisc D2N(0,1), and the expansion of which in a multiple power series leads to coefficients, which are values of a MD for several occupation number sets (n 1 ,n 2 , . . . ,n N ) or (m 1 ,m 2 , . . . ,m N ). Symmetry or invariance properties of the MD in respect to the exchange of parameters and the exchange of the occupation number sets (n 1 ,n 2 , . . . ,n N ) and (m 1 ,m 2 , . . . ,m N ) are investigated. For the special case, if the mixing matrix is a unit matrix, the multidimensional GF reduces to a product of one-dimensional GFs, each of which depends on parameters and complex variables of one separate component only. The advantages and disadvantages of this separation will be discussed. For illustrative purpose, relief plots of the MD are presented, demonstrating the effect of mode mixing

Open Access June 2, 2014

Electronic Conductivity of NaCl-KCl Equimolar Melt Containing Eu(III) and Eu(II) Complexes by Electrochemical Impedance Spectroscopy

Sergey A. Kuznetsov, Marcelle Gaune-Escard

Page range: 486-490

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Abstract

The electronic conductivity of molten equimolar NaCl-KCl containing Eu(III) and Eu(II) complexes was studied by electrochemical impedance spectroscopy. The ratio between electronic and electrolyte resistance as a function of the electrode potential was determined. The electronic conductivity was found to be maximal when the amounts of Eu(III) and Eu(II) are about equal. The electronic conductivity of this melt does not exceed 2.3% of the ionic conductivity. Deviation from the molar ratio Eu(III)/Eu(II) = 1 led to a considerable diminution of the electronic conductivity.

Open Access June 2, 2014

The Ag I and Au I Resonance Line Broadening in Helium Plasma

Stevan Djeniže, Aleksandar Srećković, Srdjan Bukvić, Nikola Vitas

Page range: 491-498

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Abstract

The shapes and shifts of the resonance spectral lines of neutral silver (Ag I: 328.068 and 338.289 nm) and gold (Au I: 242.795 and 267.595 nm) have been measured in a laboratory helium plasma of about 18,500 K electron temperature and an electron density ranging between 0.78 · 10 23 and 1.24 · 10 23 m −3 . Stark broadening has been found as the dominant mechanism of the line shape and position formation. Our measured Ag I and Au I resonance line Stark widths (W) and shifts (d) are the first reliable experimental data. They are compared with calculated single Ag I and Au IW and d data based on a semiclassical approach. The measured values are higher than the calculated ones, especially of the Au I resonance lines. Besides, we have calculated the hyperfine structure (hfs) components and their relative intensities of the mentioned Ag I and Au I lines. Strong asymmetry between the red and blue components of the hfs was found. A modified version of the linear, low-pressure, pulsed arc was used as plasma source operated in helium with silver and gold atoms as impurities, evaporated from silver and gold cylindrical plates located in the homogeneous part of the discharge providing conditions free of self-absorption. At the above mentioned helium plasma conditions the splitting in the hyperfine structure (Δ hfs ) of the Ag I and Au I resonance lines has been overpowered by Stark and Doppler broadenings. We estimate that at electron densities below 10 20 m −3 and electron temperatures below 10,000 K the hfs components in the 267.595 nm and 242.795 nm Au I lines play an important role in the line shape formation, and the resulting line profiles can be used for temperature estimation in optically thin plasmas

Open Access June 2, 2014

Two-Dimensional Nutation NQR Broad-Line Spectra in Oriented Samples

Nicolay Sinyavsky, Irina Korneva, Michał Ostafin, Bolesław Nogaj, Mariusz Maćkowiak

Page range: 499-504

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Abstract

The NQR nutation method to determine the electric field gradient asymmetry parameter η in systems, where the resonance line is so broad that the radio frequency field can excite only a portion of the nuclear spins, is presented. In this situation, the recently developed spectroscopic methods are not applicable. Two-dimensional nutation NQR spectra of oriented powders are calculated and used to determine η at particular frequencies along a broad NQR line. The proposed method is useful for single crystals, oriented powders, glasses, and disordered systems even for small values of the asymmetry parameter. Therefore it can be used to evaluate fluctuations in η and the quadrupole coupling constant e 2 qQ due to inhomogeneities. We demonstrate the application of this method to oriented chalcogenide semiconducting glasses.

Open Access June 2, 2014

Theoretical Explanation of the EPR Parameters of Tetragonal Ti³⁺ Centers in ZnSe and CdS_0.75Se_0.25 Semiconductors

Xiao-Xuan Wu, Wen-Ling Feng, Qing Zhou, Wen-Chen Zheng

Page range: 505-508

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Abstract

The electron paramagnetic resonance (EPR) parameters (g factors g || , g⊥ and hyperfine structure constants A || , A⊥) of the tetragonal Ti 3+ centers in ZnSe and CdS 0.75 Se 0.25 semiconductors are calculated from high-order perturbation formulas based on the cluster approach. In these formulas, both the contribution from the spin-orbit coupling parameters of the central 3d n ion and that of ligands are considered. The calculated results show reasonable agreement with the observed values. The defect structures of the tetragonal Ti 3+ centers in both semiconductors caused by the static Jahn-Teller effect are suggested

About this journal

Objective
A Journal of Physical Sciences: Zeitschrift für Naturforschung A (ZNA) is an international scientific journal which publishes original research papers from all areas of experimental and theoretical physics. Authors are encouraged to pay particular attention to a clear exposition of their respective subject, addressing a wide readership. In accordance with the name of our journal, which means “Journal for Natural Sciences”, manuscripts submitted to ZNA should have a tangible connection to actual physical phenomena. In particular, we welcome experiment-oriented contributions.

Manuscripts considered for publication in A Journal of Physical Sciences: Zeitschrift für Naturforschung A undergo high-level refereeing. Mere formal correctness of a paper is not sufficient for its acceptance. Moreover, articles reporting a merely marginal extension of already existing knowledge are considered unsatisfactory. Instead, the key quality a publication in A Journal of Physical Sciences: Zeitschrift für Naturforschung A should possess is that it makes a genuine contribution to the advancement of its topic.

Topics

Atomic, Molecular & Chemical Physics
Dynamical Systems & Nonlinear Phenomena
Gravitation & Cosmology
Hydrodynamics
Quantum Theory
Solid State Physics & Materials Science
Thermodynamics & Statistical Physics

Article formats
Original research articles, research notes, letters and review articles from all areas of theoretical and experimental physics

Information on submission process

Volume 61 Issue 9

Issue of Zeitschrift für Naturforschung A

Variable Separation Solutions for the (2+1)-Dimensional Breaking Soliton Equation

Abstract

New Travelling Wave Solutions for an Asymmetric Model of a Rod in a Lattice Fluid with Nonlinear Advection

Abstract

Change of Electroweak Nuclear Reaction Rates by CP- and Isospin Symmetry Breaking – A Model Calculation

Abstract

On a Generating Function and its Probability Distributions. A Contribution to the Theory of Transition Rates I

Abstract

On a Generating Function and its Probability Distributions. A Contribution to the Theory of Transition Rates II

Abstract

Electronic Conductivity of NaCl-KCl Equimolar Melt Containing Eu(III) and Eu(II) Complexes by Electrochemical Impedance Spectroscopy

Abstract

The Ag I and Au I Resonance Line Broadening in Helium Plasma

Abstract

Two-Dimensional Nutation NQR Broad-Line Spectra in Oriented Samples

Abstract

Theoretical Explanation of the EPR Parameters of Tetragonal Ti3+ Centers in ZnSe and CdS0.75Se0.25 Semiconductors

Abstract

Theoretical Explanation of the EPR Parameters of Tetragonal Ti³⁺ Centers in ZnSe and CdS_0.75Se_0.25 Semiconductors