Published by De Gruyter

Volume 59 Issue 1-2

Issue of Zeitschrift für Naturforschung A

Submit manuscript

Contents
Journal Overview

Open Access June 2, 2014

Ground-State Energy of a Weakly Interacting Bose Gas: Calculation Without Regularization

Christoph Weiss, Martin Block, Dave Boers, André Eckardt, Martin Holthaus

Page range: 1-13

More Download PDF

Abstract

The textbook calculation of the ground-state energy of a dilute gas of Bose particles is examined in detail, and certain mathematical inconsistencies are pointed out. On the basis of this analysis, a refined approach suitable for soft interaction potentials which lend themselves to a low-order Born approximation is developed. This procedure emphasizes the low-density character of the resulting formula for the ground-state energy, and avoids all divergent expressions at intermediate stages of the computation. It is stressed that the standard Bogoliubov approximation, if not augmented by some additional device, leads to an error which manifests itself already in the lowest order of the density. - PACS 03.75.Hh, 05.30.Jp, 03.65.Nk.

Open Access June 2, 2014

The Structures and the Interactions of Soliton in two (2+1)-dimensional KdV-Type Equations

Hang-yu Ruan

Page range: 14-22

More Download PDF

Abstract

Exact solutions in two (2+1)-dimensional KdV-type (Sawada-Kodera and Boussinesq) equations are presented by using the bilinear method. The N-breather solution, the solution to describe the interaction between a line soliton and a y-periodic soliton, and the solution to express the interaction between two y-periodic solitons are included in our results. Detailed behavior of interactions between a line soliton and a y-periodic soliton for the SK equation and between two y-periodic solitons for the BS equation are illustrated both analytically and graphically. For these two equations, we only discuss the repulsive interaction keeping the shapes of the soliton unchanged.

Open Access June 2, 2014

Elliptic Function Solutions of (2+1)-dimensional Longwave – Shortwave Resonance Interaction Equation via a sinh-Gordon Expansion Method

Zhenya Yan

Page range: 23-28

More Download PDF

Abstract

With the aid of symbolic computation, the sinh-Gordon equation expansion method is extended to seek Jacobi elliptic function solutions of (2+1)-dimensional long wave-short wave resonance interaction equation, which describe the long and short waves propagation at an angle to each other in a two-layer fluid. As a result, new Jacobi elliptic function solutions are obtained. When the modulus m of Jacobi elliptic functions approaches 1, we also deduce the singular oliton solutions; while when the modulus m→0, we get the trigonometric function solutions. - PACS: 02.30.Jr, 03.40.Kf

Open Access June 2, 2014

Study on New Doubly-periodic Solutions of two Coupled Nonlinear Wave Equations in Complex and Real Fields

Zhenya Yan

Page range: 29-34

More Download PDF

Abstract

In this paper, new doubly-periodic solutions in terms of Weierstrass elliptic functions are investigated for the coupled nonlinear Schr¨odinger equation and systems of two coupled real scalar fields. Solitary wave solutions are also given as simple limits of doubly periodic solutions. - PACS: 03.40.Kf; 02.30Ik

Open Access June 2, 2014

Magnetic and Electric Studies of a New Cu(II) Perovskite-like Material

Mohga F. Mostafa, Ahmed A. A Youssef

Page range: 35-46

More Download PDF

Abstract

Thermal analysis of a lipid-like bilayer of [(CH 2 ) 9 (NH 3 ) 2 ]CuCl 4 indicates one minor transition at 303 K and the following five major ones (with entropies in J/K-mole): The initial magnetic susceptibility at 320 Hz and a magnetic field of 160 A/m in the temperature range 75 - 290 K revealed a Curie-Weiss behavior of phase (V) and possible ferromagnetic ordering of phases (VI) and (IV) at low temperatures. The variation of the dielectric permittivity with temperature at 60.0 Hz - 100 kHz indicates large changes of the dipole moment at the transition temperatures. The conductivity is thermally activated and frequency dependent, following the universal power law: σ (ω) =σ dc +A(T)ω s(T) . Values of s being phase dependent. For phase (I), T > 383 K, band type conduction prevails. Hopping conduction is found in phases(II) and (III). Comparison with other Cuand Cd-containing materials is made. -PACS: 76, 77

Open Access June 2, 2014

Defect Structure of the Tetragonal Cu²⁺ Center in PbTio₃: Cu²⁺ Crystal

Xiao-Xuan Wu, Wen-Chen Zheng, Sheng Tang

Page range: 47-50

More Download PDF

Abstract

The defect structure of the tetragonal Cu 2+ center in PbTiO 3 : Cu 2+ crystal is studied by analyzing the EPR g factors and hyperfine structure constants. From the study, we suggest that an oxygen vacancy occurs in the nearest-neighbors site of Cu 2+ due to charge compensation, and that the offcenter displacement of Cu 2+ is smaller than that of the replaced host ion Ti 4+ . The reasonableness of the defect structure is discussed.

Open Access June 2, 2014

A NMR Spin-Echo Study of Diffusion in Molten Salts

Günter Palmer, Joachim Richter, Manfred D. Zeidler

Page range: 51-58

More Download PDF

Abstract

Pressure-dependent measurements of the cationic self-diffusion coefficients of molten (Na, Li)NO 3 were carried out at 613 K. The pressure range lies between ambient pressure and 200 MPa. A new high-pressure probe, operating with heating coils, was constructed from titanium alloy. The temperature difference across the probe could be confined to 2.5 K. By use of a switchable high-frequency coil the nuclei lithium and sodium could be measured in succession within the same sample. The activation volumes are composition-dependent and range from 5 to 9 cm 3 mol −1 .

Open Access June 2, 2014

An NMR Spin-Echo Study of Diffusion in a Room-Temperature Molten Salt

Günter Palmer, Joachim Richter, Manfred D. Zeidler

Page range: 59-63

More Download PDF

Abstract

Pressure-dependent measurements of self-diffusion in the room-temperature molten salt (RTMS) N,N-butylmethylimidazoliumhexafluorophosphate were carried out at 298 and 308 K. The pressure range lied between ambient pressure and 300 MPa. In addition, methanolic solutions of this RTMS were investigated at ambient pressure. The self-diffusion coefficients of both components are reported as functions of concentration and temperature in the range 293 - 313 K. A modified version of a recently published high-pressure probe is described.

Open Access June 2, 2014

Synthetic, Infrared, ¹H And ¹³C NMR Spectral Studies on Potassium Salts of N-Chloroarylsulphonamides

K. Jyothi, B. Thimme Gowda

Page range: 64-68

More Download PDF

Abstract

Several N-chloroarylsulphonamides of the configuration, 4-X-C 6 H 4 SO 2 (K)NCl・xH 2 O (where X = H, CH 3 , C 2 H 5 , F, Cl or Br) and i-X, j-YC 6 H 3 SO 2 (K)NCl・xH 2 O (where i-X, j-Y = 2,3-(CH 3 ) 2 ; 2,4- (CH 3 ) 2 ; 2,5-(CH 3 ) 2 ; 2-CH 3 ,4-Cl; 2-CH 3 ,5-Cl; 3-CH 3 ,4-Cl; 2,4-Cl 2 or 3,4-Cl 2 ) are prepared, characterised, and their infrared spectra in the solid state and NMR spectra in solution are measured and correlated. Comparison of the infrared spectra of the potassium salts of N-chloro-arylsulphonamides with the corresponding arylsulphonamides shows that the strong absorptions in the range 947 - 933 cm −1 are due to N-Cl stretching vibrations. The effect of ring substitution on the N-Cl frequencies is non-uniform. The frequencies in the ranges 1404 - 1370 cm −1 and 1149 - 1125 cm −1 are respectively assigned to S=O asymmetric and symmetric vibrations. The effect of substitution in the phenyl ring in terms of electron withdrawing and electron donating groups is non-systematic. Empirical correlations relating the chemical shifts to the structures are considered. The chemical shifts of aromatic protons and carbons in all the N-chloroarylsulphonamides have been calculated by adding substituent contributions to the shift of benzene, as per the principle of substituent addition. Considering the approximation made, the agreement between the calculated and experimental chemical shifts is reasonably good.

Open Access June 2, 2014

Infrared, ¹H and ¹³C NMR Spectral Studies on Di- and Tri-substituted N-Aryl Amides, 2,6-X₂C₆H₃NHCOCH_{3 – I}X_i and 2,4,6-X₃C₆H₂NHCOCH_{3 – I}X_i (X = Cl or CH₃ and I = 0, 1, 2 or 3)

B. Thimme Gowda, K. M. Usha, K. Jyothi

Page range: 69-76

More Download PDF

Abstract

Several di- and tri-substituted amides of the general formula, 2,6-X 2 C 6 H 3 NHCOCH 3−i X i and 2,4,6-X 3 C 6 H 2 NHCOCH 3−i X i (X = Cl or CH 3 and i = 0, 1, 2, or 3) are prepared, characterised, and their infrared spectra in the solid state and 1 H and 13 C NMR spectra in solution are studied. The C=O stretching vibrations of N-(2,6-dichlorophenyl)- and N-(2,6-dimethylphenyl)-amides appear as strong absorptions in the ranges 1707 - 1658 cm −1 and 1700 - 1647 cm −1 , respectively, while the N-H stretching vibrations of N-(2,6-dichlorophenyl)- and N-(2,6-dimethylphenyl)-amides appear as strong vibrations in the ranges 3271 - 3209 cm −1 and 3285 - 3214 cm −1 , respectively. The N-H stretching vibrations of N-(2,4,6-trichlorophenyl)- and N-(2,4,6-trimethylphenyl)- amides also appear as strong absorptions in the ranges 3370 - 3212 and 3283 - 3225 cm −1 , respectively, while those of the C=O vibrations appear in the ranges 1688 - 1617 and 1704 - 1647 cm −1 . The analysis of the C=O and N-H absorption frequencies of all amides of the general formula X i C 6 H 5 − i NHCOCH 3−i X i (where X = Cl or CH 3 , and i = 0, 1, 2 or 3) indicates that their variations do not show regular trends with substitution either in the phenyl ring or in the side chain. The chemical shifts of both the aromatic protons and the aromatic carbons of all the amides are calculated in two ways, either by adding the incremental shifts due to -COCH 3−i X i groups and the substituents in the benzene ring to the chemical shifts of the corresponding aromatic protons or carbons of the parent aniline, or by adding the incremental shifts due to -NHCOCH 3−i X i groups and the substituents in the benzene ring to the chemical shift of the benzene proton or carbon. The calculated chemical shifts of the aromatic protons and carbons of all the substituted amides by both methods lead to almost the same values in most cases and agree well with the observed chemical shifts, indicating that the principle of additivity of the substituent effects is valid in these compounds.

Open Access June 2, 2014

Electrical Conductivity of Molten Binary Ndbr₃ – Alkali Bromide Mixtures

S. Gadzuric, E. Ingier-Stocka, L. Rycerz, M. Gaune-Escard

Page range: 77-83

More Download PDF

Abstract

Electrical conductivity of liquid binary NdBr 3 - alkali metal bromide mixtures was measured as a function of temperature over the whole composition range. Prior to these measurements, NdBr 3 and alkali bromides were reinvestigated: a new assessment of literature data was made because of the discrepancy with reference values on NdBr 3 , LiBr and CsBr. The classical Arrhenius equation describes well our electrical conductivity data for mixtures. These results are discussed in terms of complex formation in the melts.

Open Access June 2, 2014

Phase Diagram of the TbBr₃-KBr Binary System

L. Rycerz, M. Gaune-Escard

Page range: 84-90

More Download PDF

Abstract

The phase equilibrium of the TbBr 3 -KBr has been established by Differential Scanning Calorimetry. This system has the three compounds K 3 TbBr 6 , K 2 TbBr 5 , and KTb 2 Br 7 and two eutectics located at (χ Tb = 0.163 (885 K) and (χ Tb = 0.433 (697 K). K 3 TbBr 6 undergoes a solid-solid phase transition at 691 K and melts congruently at 983 K with the corresponding enthalpies 8.0 and 48.0 kJ mol −1 . K 2 TbBr 5 melts incongruently at 725 K, and KTb 2 Br 7 at 741 K. The latter forms at 694 K, a temperature very close to that (697 K) of one of the two eutectics also existing in the binary system.

Open Access June 2, 2014

Steady State and Dynamic Photophysical Properties of 2-Benzoimidazoleacetonitrile- α-Phenylmethylenes and 1-Aryl-2,2-Dicyanoethenes

Irina Petkova, Peter Nikolov, Stefan Metzova

Page range: 91-96

More Download PDF

Abstract

The steady state and dynamic photophysical characteristics of newly synthesized 2-benzoimidazoleacetonitrile- α-phenylmethylenes (BIA’s) and 1-aryl-2,2-dicyanoethenes (DCE’s) have been investigated in solution at 300 K and in a frozen matrix at 77 K. The compounds have a very low or no emission in solution at 300 K both in non-polar and polar solvents. While in BIA’s a significant fluorescence ability is registered in a frozen ethanol matrix at 77 K, freezing solutions of DCE’s at 77 K does not lead to the appearance of either fluorescence or phosphorescence at 77 K even in the presence of C 2 H 5 J. The comparison of the fluorescence ability in aprotic and protic solvents does not show any evidence for the specific influence of the protondonating ability of the solvents on the weak fluorescence caused by the formation of intramolecular hydrogen bonds in excited states. The high fluorescence quantum yield of BIA’s in a frozen matrix at 77 K indicates that intramolecular libration of two heavy groups in the allyl chain is the reason for the weak fluorescence at 300 K. Quantum-chemical calculations support the hypothesis of quenching processes in the excited state of BIA’s at 300 K.

Open Access June 2, 2014

Studies on Room Temperature Ferroelectric Liquid Crystal, 12CN5(R*)

A. K. George, Venkata G. K. M. Pisipati, C. Carboni, S.H. Al Harthi, J. Naciri

Page range: 97-99

More Download PDF

Abstract

Characterization studies are performed on a ferroelectric liquid crystal, 12CN5(R*). Phase sequence and transition temperatures are obtained by polarized thermal microscopy. Temperature variation of spontaneous polarization and tilt angle in the smectic C* phase are found to agree with the mean-field predictions. Results obtained for the variation of the switching time and torsional viscosity with temperature are also presented.

Open Access June 2, 2014

Zero-field Splitting and Local Lattice Distortions for Fe³⁺ Ions in Some I_b-III_b-VI₂ Semiconductors

Wen-Chen Zheng, Hui-Ning Dong, Sheng Tang, Jian Zi

Page range: 100-102

More Download PDF

Abstract

The EPR zero-field splitting D for Fe 3+ ions in some I b -III b -VI 2 semiconductors is calculated with the superposition model. The calculated D values, when using the local rotation angles τ (Fe 3+ ) for Fe 3+ in CuGaS 2 and AgGaS 2 crystals, are consistent with the observed values, whereas for Fe 3+ in CuAlS 2 crystal they are not. The calculated results are discussed. The local lattice distortions except the local rotation angles τ for Fe 3+ in CuAlS 2 are suggested.

Open Access June 2, 2014

The Electron Paramagnetic Resonance Spectrum of γ-Irradiated Dimethyl Malonic Acid

Biray Aşik, Mehmet Birey

Page range: 103-104

More Download PDF

Abstract

The electron paramagnetic resonance of γ -Irradiated single crystals of dimethyl malonic acid [(CH 3 ) 2 C(COOH) 2 ] has been studied for different orientations of the crystal in a magnetic field. The radicals produced by gamma irradiation have been investigated between 123 and 300 K. The spectra were found to be temperature independent, and radiation damage centres were attributed to [(CH 3 ) 2 C(COOH) 2 ]+ radicals. The g factor and hyperfine coupling constants were found to be almost isotropic with average values g = 2.0036, a (COOH) 2 = 0.5 mT, a (CH 3 ) 2 = 2.1 mT, respectively, and spin density ρ = 91% of the [(CH 3 ) 2 C(COOH) 2 ]+ radical.

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 & Optical Physics
Chemical Physics
Dynamical Systems & Nonlinear Phenomena
Fundamental Concepts of Physical Sciences
Gravitation & Cosmology
Hydrodynamics & Plasma Physics
Nuclear Physics & Particle Physics
Quantum Field 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 59 Issue 1-2

Issue of Zeitschrift für Naturforschung A

Ground-State Energy of a Weakly Interacting Bose Gas: Calculation Without Regularization

Abstract

The Structures and the Interactions of Soliton in two (2+1)-dimensional KdV-Type Equations

Abstract

Elliptic Function Solutions of (2+1)-dimensional Longwave – Shortwave Resonance Interaction Equation via a sinh-Gordon Expansion Method

Abstract

Study on New Doubly-periodic Solutions of two Coupled Nonlinear Wave Equations in Complex and Real Fields

Abstract

Magnetic and Electric Studies of a New Cu(II) Perovskite-like Material

Abstract

Defect Structure of the Tetragonal Cu2+ Center in PbTio3: Cu2+ Crystal

Abstract

A NMR Spin-Echo Study of Diffusion in Molten Salts

Abstract

An NMR Spin-Echo Study of Diffusion in a Room-Temperature Molten Salt

Abstract

Synthetic, Infrared, 1H And 13C NMR Spectral Studies on Potassium Salts of N-Chloroarylsulphonamides

Abstract

Infrared, 1H and 13C NMR Spectral Studies on Di- and Tri-substituted N-Aryl Amides, 2,6-X2C6H3NHCOCH3 – IXi and 2,4,6-X3C6H2NHCOCH3 – IXi (X = Cl or CH3 and I = 0, 1, 2 or 3)

Abstract

Electrical Conductivity of Molten Binary Ndbr3 – Alkali Bromide Mixtures

Abstract

Phase Diagram of the TbBr3-KBr Binary System

Abstract

Steady State and Dynamic Photophysical Properties of 2-Benzoimidazoleacetonitrile- α-Phenylmethylenes and 1-Aryl-2,2-Dicyanoethenes

Abstract

Studies on Room Temperature Ferroelectric Liquid Crystal, 12CN5(R*)

Abstract

Zero-field Splitting and Local Lattice Distortions for Fe3+ Ions in Some Ib-IIIb-VI2 Semiconductors

Abstract

The Electron Paramagnetic Resonance Spectrum of γ-Irradiated Dimethyl Malonic Acid

Abstract

Defect Structure of the Tetragonal Cu²⁺ Center in PbTio₃: Cu²⁺ Crystal

Synthetic, Infrared, ¹H And ¹³C NMR Spectral Studies on Potassium Salts of N-Chloroarylsulphonamides

Infrared, ¹H and ¹³C NMR Spectral Studies on Di- and Tri-substituted N-Aryl Amides, 2,6-X₂C₆H₃NHCOCH_{3 – I}X_i and 2,4,6-X₃C₆H₂NHCOCH_{3 – I}X_i (X = Cl or CH₃ and I = 0, 1, 2 or 3)

Electrical Conductivity of Molten Binary Ndbr₃ – Alkali Bromide Mixtures

Phase Diagram of the TbBr₃-KBr Binary System

Zero-field Splitting and Local Lattice Distortions for Fe³⁺ Ions in Some I_b-III_b-VI₂ Semiconductors