Rotational gJ -factors of the following (IVa/VIa)-molecules have been measured: 72 Ge 32 S: -0.06828(11), 120 Sn 80 Se: 0.03007(10), 74 Ge 80 Se: -0.03765(6), 120 Sn 130 Te: -0.02212(13), 74 Ge 130 Te: -0.03193 (10), 208 Pb 32 S: -0.06440 (4), 120 Sn 32 S: -0.06120(7), 208 Pb 80 Se: -0.02764(7). The systematics of the rotational magnetic moments of class (IVa/VIa) -molecules are discussed.

Open Access June 2, 2014

Zum Rotationsspektrum des InBr / On the Rotational Spectrum of InBr

E. Tiemann, U. Köhler, J. Hoeft

Page range: 6-9

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Abstract

The hyperfine structure of the rotational transition J = 1→2 in the frequency range of 6.6 GHz was measured. The analysis yields the following quadrupole coupling constants: eqvQ ( 115 In) = [-634.62 + 2.52 (ν+1/2) ± 0.45] MHz, eqvQ ( 79 Br) = [110.38 + 0.50 (ν+1/2) ± 0.50] MHz, eqvQ ( 81 Br) = [91.88 + 0.45 (ν+1/2) ± 0.50] MHz. The new determinations are consistent with the systematic trends of the III/VII diatomic molecules and remove the discrepancies of the older measurements of Barrett and Mandel 1 .

Open Access June 2, 2014

Effect of a Ring on the Stability of Polycyclic Conjugated Molecules

Slobodan Bosanac, Ivan Gutman

Page range: 10-12

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Abstract

A graph theoretical method is developed which enables to calculate the contribution of a particular ring to the total π-electron energy of a conjugated molecule.

Open Access June 2, 2014

Ion-Molekül-Reaktionen und Ladungsaustausch bei Stößen von O^– auf O₂ / Ion-Molecule Reactions and Charge Transfer in Collisions of O^– on O₂

D. Vogt, W. Dreves, J. Mischke

Page range: 13-16

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Abstract

Investigations of the cross section for the reaction O - + O 2 → O 2 - + O have been made for laboratory kinetic energies 0-100 eV. The reaction shows a sharp maximum in the cross section at low energies (5 eV lab.). By the use of the primary ion 18 O - it can be shown that above 20 eV (lab.) there is only charge exchange whereas in the lower energy region ion-molecule-reactions as well as charge exchange occure. The reaction O - + O 2 → O + + … has also been observed above 27 eV (lab.).

Open Access June 2, 2014

⁸Li Emission in 1.8 GeV/c K^– -Meson Interactions in Nuclear Emulsion

P. Mandal, D. K. Bhattacharya, M. Saha, P. K. Sen, P. C. Bhattacharya, S. N. Ghosal

Page range: 17-20

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Abstract

Out of about 16,000 stars found by an area scan of 1.8 GeV/c K - -meson interactions with emulsion nuclei, 120 'hammer tracks' have been collected. The corrected production rate is (1.30 ± 0.12)^. The forward to backward ratio indicates isotropic emission of 8Li fragments. The emission of short recoils at the primary vertex shows a definite correlation with the 8 Li fragments.

Open Access June 2, 2014

The Emission Coefficient of the Continuum in an Argon and Nitrogen Plasma at High Temperatures

K. Erhardt, I. Meyer, P. Stritzke

Page range: 21-27

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Abstract

The continuum emission of an argon-and nitrogen plasma developed in an electrical discharge has been investigated in the wavelength range from 3000 Å to 6700 Å. To this purpose the time-and radial dependent plasma parameters such as temperature and the total pressure have been determined in the high conducting stage of the spark by measuring several line intensities. The continuum coefficient was calculated from these data according to the Kramers-Unsöld theory. The comparison of the theoretical and the measured values shows deviations which are discussed. In the case of the argon continuum the ξ-factors for T = 14 000 K agree with the calculated values of Schlüter and the experimental ones of Schulz-Gulde. In the case of the nitrogen plasma the ξ-factors have been determined in the temperature interval from 18 000 K to 45 000 K. Since at these temperatures the particles N II -N IV contribute to the total continuum coefficient, the measured ξ-factors can only be correlated to ξ II , ξ III , ... in a narrow temperature range. The measured correction factor ξ for λ = 5050 Å has been applied to determine the temperatures and the pressure of a laser produced spark. The plasma parameters agree with those determined by measuring the line-intensity of the N II -line at 5000 A.

Open Access June 2, 2014

The Double Diffraction Model for LEED-Intensity Spectra of the Clean Pt(100) Surface

K. Heinz, P. Heilmann, K. Müller

Page range: 28-32

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Abstract

The intensity spectra of the superstructure diffraction spots of the clean platinum (100) surface are presented for normal or nearly normal incidence. Their gross features are interpreted in terms of multiple diffraction contributions. It is shown that most of the maxima in the spectra can be explained by double diffraction processes from an idealized pure hexagonal surface layer and quadratic bulk layers. Alternative models in which the surface layer exchanges already all occuring reciprocal lattice vectors would predict additional peaks which, however, do not arise. Therefore superstructure features of the surface layer are assumed to be of second order. Thus double diffraction involving only idealized hexagonal and quadratic structures seems to dominate the diffraction behaviour of clean Pt(100).

Open Access June 2, 2014

Formation of Periodic Ripples in a Surface Skin

Fred Fischer

Page range: 33-39

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Abstract

A solid elastic skin on a liquid surface aquires a periodic ripple formation when a compressive strain surpasses a critical value. From a calculation the ripple wavelength is found to be proportional to the 3/4th power of the skin thickness. This instability can be described as a kind of second order phase transition, where a relative amplitude of the ripple wave is the order parameter. In addition, when the skin area is abruptly compressed the ripple wavelength depends on the magnitude of the compressive strain. Examples for skin rippling with wavelengths between 10 μm and 100 m are discussed.

Open Access June 2, 2014

Nonlinear Oscillations in Chemical Networks as Symmetries of Transformation Groups

H. G. Busse, B. Havsteen

Page range: 40-46

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Abstract

The description of phenomena created by nonlinear oscillators with the aid of transformation groups has been attempted. Such a treatment of the chemical model of Dreitlein and Smoes was met with success. The mathematical approach is based on an application of the canonical form theorem for one-parameter groups. Conditions for the occurence of limit cycles have been derived.

Open Access June 2, 2014

Comparative FTR- and Ramanspectroscopic Studies of Fundamental Mode Frequencies in LiNbO₂ and the Present Limit of Oblique Phonon Dispersion Analysis

E. Schuller, R. Claus, H. J. Falge, G. Borstel

Page range: 47-53

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Abstract

The assignments of fundamental mode frequencies in LiNbO 3 determined by IR-and Raman scattering-experiments show some characteristic differences. Comparative frustrated total reflection (FTR) -and Raman scattering-studies were carried out in order to find the origin of these discrepancies. The most serious deviation was due to the fact that in one case the ordinary phonon is observed by Raman scattering whereas the extraordinary mode is recorded only by FTR. It has been shown, on the other hand, that the oblique phonon dispersion technique did not provide arguments for the correct assignments. The main limit of the method is due to the fact that the influence of exciton states on polaritons hitherto is taken into account only by a constant high frequency dielectric 'function' (ε ∞ ). The uncertainty in the choice of a suitable ε ∞ -value allows fittings of quite diverging sets of experimentally determined fundamental frequencies.

Open Access June 2, 2014

Bestimmung partieller Diffusionskoeffizienten binären Legierungen vom Substitutionstyp mit Hilfe dünner Scheibenpaare / Determination of the Intrinsic Diffusion-coefficients of Binary Solid Solution Alloys with the Aid of Thin Plates

Th. Heumann

Page range: 54-56

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Abstract

Determination of the Intrinsic Diffusion-coefficients of Binary Solid Solution Alloys with the Aid of Thin Plates A new method for determining intrinsic diffusion-coefficients in binary solid solutions of the substitutional typ is described. For this, thin plates are used having such a thickness that during annealing the specimen becomes nearly homogenious. From the shift of the original interface one obtaines the ratio of the intrinsic diffusion-coefficients for the concentration in the Kirkendall interface.

Open Access June 2, 2014

Hypersonic Velocity, Absorption and Relaxation in Molten C_SNO₃

H. E. Gunilla Knape, Lena M. Torell

Page range: 57-60

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Abstract

Brillouin spectra of molten C S NO 3 were investigated for scattering angles between 40 and 140° and in a temperature interval of 420-520 °C. An Ar + singlemode laser was used for excitation and the total instrumental width was ~265 MHz. The measured frequency shifts and linewidths of the Brillouin components were used to determine velocities and attenuations of thermal sound waves in the frequency range 2.3-7.0 GHz. A dispersion of 4-5% was found between the present hyper sonic velocities and reported ultrasonic velocities. A considerable decrease in attenuation with frequency was observed in the investigated frequency range, with the value at high frequency ap proaching the classical attenuation. The results are in good agreement with Mountain's theory of a single relaxation time. The relaxation time of the bulk viscosity coefficient was calculated to 1.2×10 -10 S .

Open Access June 2, 2014

NMR Investigation of Order Fluctuations, Self-Diffusion and Rotational Motions in the Nematic Liquid Crystal MBBA by T₁-Relaxation Spectroscopy

V. Graf, F. Noack, M. Stohrer

Page range: 61-72

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Abstract

We report on measurements of the proton spin T 1 relaxation dispersion at various temperatures in the nematic phase of the liquid crystal MBBA in the Larmor frequency range from 2 kHz to 270 MHz, which exceeds previous studies by more than 3 orders of magnitude. The new results cannot be interpreted in terms of either order fluctuations or self-diffusion as recently proposed by Doane et al. 1 and Blinc et al. 2 , respectively. Instead, the dispersion and its temperature dependence indicate the significance of at least three relaxation mechanisms, namely order fluctuations (OF), self-diffusion (SD) and rotation of the molecular ellipsoids about the short axis (R). The combined OF-SD-R model presented in this work allows a quantitative analysis of the experimental findings! The correlation times and activation energies of the three molecular reorientations evaluated from the T 1 dispersion by means of a computer optimization procedure are in essential agreement with data provided by other spectroscopic methods [light scattering, tracer technique, dielectric relaxation], but differ from former NMR conclusions.

Open Access June 2, 2014

Systematic Patterns in the E1 Decays in ²¹Ne and ²³Na: A Means of Identifying High Spin States?

A. A. Pilt

Page range: 73-75

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Abstract

The El decays from members of the lowest K π = 1/2 - bands in 21 Ne and 23 Na are shown to exhibit remarkable, but dissimilar, patterns, which can be reproduced with a simple two-parameter expression. This may have useful application in identifying high-spin members of the K π = 1/2 - and 3/2 + bands in both nuclei.

Open Access June 2, 2014

Pseudo-exact Force Constants for Tetramethyls of Group IVA Metals and Molecular Force Fields for Some Tetrahedral Molecules or Ions

A. K. Dublish, B. B. Srivastava, D. K. Sharma, U. P. Verma, A. N. Pandey

Page range: 76-78

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Abstract

Recently reported Coriolis constants of tetrahedral tetramethyls of group IVA metals from the vapour phase IR spectra have been used to determine the pseudo-exact force constants with the aid of the point mass model. The symmetrized force constants for tetramethyls of group IVA and some tetrahedral molecules and ions have also been computed following thhe L-F approximation method. The results are compared with exact or pseudo-exact force constants and with those force constants obtained from different approximation methods. The validity of the method has been tested.

Open Access June 2, 2014

Untersuchung von Level-Crossing-Signalen an schnellen He-Atomen in inhomogenen Magnetfeldern / Investigation of Level-crossing Signals on High-velocity He-atoms in Inhomogeneous Magnetic Fields

G. v. Oppen, W.-D. Perschmann

Page range: 79-83

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Abstract

In level-crossing experiments on high-velocity atoms, the shape of the observed signals depends sensitively on inhomogeneities of the applied magnetic field. With regard to the interpretation of such signals, we investigated the magnetic-field dependence of He I-fluorescence light excited by He-ion-He-atom collisions. Due to the inhomogeneity of the applied magnetic field, the observed level-crossing signals have a distorted shape with an oscillating structure in the wings. Taking into account the motion of the excited atoms, the shape of the signals will be explained.

Open Access June 2, 2014

Population Density Measurements in a Partially Ionized Freejet Expansion Flow

Akira Kimura, Michio Nishida

Page range: 84-87

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Abstract

Population densities of the 4p and 5p levels of argon atoms were measured along a freejet centerline of partially ionized argon in a low density plasma wind tunnel. The measured axial distribution of the 4p[3/2] level population has been compared with a theoretical prediction using a modified Thomson's formula for the excitation cross sections.

Open Access June 2, 2014

Delayed Emission from Green Algae “Chlorella pyrenoidosa” at Various Temperatures

F. Drissler, W. Hägele, D. Schmid, H. C. Wolf

Page range: 88-95

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Abstract

Comparative studies of prompt and delayed emission from whole cells of Chlorella pyrenoidosa are presented for various temperatures between 4.2 and 300 K. Prompt emission was excited with continuous light (wavelengths between 420 and 670 nm). Light pulses (duration 6.9 msec) have been used to excite delayed emission. Their wavelength had to be shorter than 600 nm for investigations at 77 K. A linear dependence of the delayed emission intensity on the excitation intensity at low temperatures (4.2 and 77 K) favours a one-quantum-mechanism to be responsible for delayed light production. The response of the total intensities on temperature shows a similar behaviour for both types of emission up to 200 K. Above 200 K they behave quite differently.

Open Access June 2, 2014

Excess Volumes of Mixtures of Acetone, Chloroform, Carbon tetrachloride, 1,4-Dioxane and Tetrahydrofuran with o-Dichlorobenzene

M. S. Dhillon

Page range: 96-97

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Abstract

Excess volumes of mixtures of o-dichlorobenzene with acetone, chloroform, carbon tetrachloride, 1,4-dioxane, and tetrahydrofuran have been measured at 293.15 K as a function of composition. The excess volume data have been used to check the one-fluid theory of mixtures with van der Waals's and Guggenheim's equations of state.

Open Access June 2, 2014

Phase Diagrams of Binary Mixtures of Phenylenediamines and Dihydroxybenzenes

M. S. Dhillon

Page range: 98-100

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Abstract

Solid - liquid equilibria for o-phenylenediamine + resorcinol, m-phenylenediamine + pyrocatechol, + resorcinol and p-phenylenediamine + pyrocatechol, + resorcinol have been studied by the thaw-melt method. The types and melting temperatures of the complexes formed in theses mixtures were ascertained from the phase diagrams.

Open Access June 2, 2014

A Covariant Semi-Classical Theory of the Radiating Electron

M. Sorg

Page range: 101-102

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Abstract

A new semi-classical equation of motion is suggested for the radiating electron. The characteristic length of the new theory is the Compton wavelength λ c (= ħ/2 m c) instead of the classical electron radius which is used in all purely classical theories of the radiating electron. However, the lowest order approximation of the radiation reaction contains only the classical radius r c .

Open Access June 2, 2014

Some Theoretical Considerations About the Excited Singlet and Triplet States of Diformamide and N-Methyl Diformamide

Julio Marañon, Oscar M. Sorarrain

Page range: 103-104

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Abstract

The molecules of diformamide and N-methyl diformamide are analysed using the CNDO-CI method. Several excited singlet and triplet states corresponding to the three possible conformers and charge distributions are discussed.

Open Access June 2, 2014

Promptes und verzögertes Spektrum des reinen Dibenzofuran-Kristalls / Prompt and, Delayed Spectrum of the Pure Dibenzofuran-crystal

K. D. Hoffmann, A. Schmillen, H. Wolff

Page range: 105-106

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Abstract

Prompt and, Delayed Spectrum of the Pure Dibenzofuran-crystal The mirror symmetry of the prompt emission and the transmission spectrum allows to estimate the S 1 →S 0 O-O transition to be at 32.64 · 10 3 cm -1 . The correspondence of the prompt emission spectrum of the DBF-crystal with the spectra of the solutions of DBF in bencene and methyl-alcohol as well as measurements of the delayed spectrum indicate a high purity of the crystal. Decay-time measurements of the delayed fluorescence and the delayed spectrum as a function of intensity of excitation light demonstrate the long wave emission in the delayed to be the phosphorescence of DBF.

Open Access June 2, 2014

Potentiom etrie Studies of the Lithium Interaction with Urea and N-Methylacetamide in Aqueous Solution

O. F. Schäfer

Page range: 107-108

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Abstract

Potentiometrie measurements of the K + and Li + activity in the presence of 4M urea or N-methylacetamide have been performed. The results support the view that Li + associates with amides.

Open Access June 2, 2014

The Photoelectron Spectra of Cyclopropyl Ketones

Jabria A. Al-Khafaji, Muthana Shanshal

Page range: 109-110

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Abstract

The photoelectron spectra of 1-and 2-methyl-cyclopropyl ketones are reported. It is found that the shifts in the MO energies of ⊿ ext.as. and ⊿ ext.s . MO's of the three membered ring are parallel to the predictions based on the perturbation of the Walsh orbitals and on the MINDO/2 calculations.

Open Access June 2, 2014

Renormalization Group Approach to a One-Dimensional Cooperative T–e Jahn-Teller System

S. Brühl, E. Sigmund

Page range: 111-112

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Abstract

A linear chain of T-e molecules exhibiting the cooperative Jahn-Teller effect is considered. Following Nauenberg's 1 treatment of the one-dimensional Ising model a renormalization group approach is used. The series-expansion of the free energy is put into a closed form.

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 32 Issue 1

Issue of Zeitschrift für Naturforschung A

Titelei

Inhaltsverzeichnis

Magnetisches Dipolmoment der zweiatomigen (IVa/VIa)-Molekeln 1Σ-Grundzustand / Magnetic Dipole Moments of Diatomic (IVa/VIa)-Molecules in their 1Σ Ground State

Abstract

Zum Rotationsspektrum des InBr / On the Rotational Spectrum of InBr

Abstract

Effect of a Ring on the Stability of Polycyclic Conjugated Molecules

Abstract

Ion-Molekül-Reaktionen und Ladungsaustausch bei Stößen von O– auf O2 / Ion-Molecule Reactions and Charge Transfer in Collisions of O– on O2

Abstract

8Li Emission in 1.8 GeV/c K– -Meson Interactions in Nuclear Emulsion

Abstract

The Emission Coefficient of the Continuum in an Argon and Nitrogen Plasma at High Temperatures

Abstract

The Double Diffraction Model for LEED-Intensity Spectra of the Clean Pt(100) Surface

Abstract

Formation of Periodic Ripples in a Surface Skin

Abstract

Nonlinear Oscillations in Chemical Networks as Symmetries of Transformation Groups

Abstract

Comparative FTR- and Ramanspectroscopic Studies of Fundamental Mode Frequencies in LiNbO2 and the Present Limit of Oblique Phonon Dispersion Analysis

Abstract

Bestimmung partieller Diffusionskoeffizienten binären Legierungen vom Substitutionstyp mit Hilfe dünner Scheibenpaare / Determination of the Intrinsic Diffusion-coefficients of Binary Solid Solution Alloys with the Aid of Thin Plates

Abstract

Hypersonic Velocity, Absorption and Relaxation in Molten CSNO3

Abstract

NMR Investigation of Order Fluctuations, Self-Diffusion and Rotational Motions in the Nematic Liquid Crystal MBBA by T1-Relaxation Spectroscopy

Abstract

Systematic Patterns in the E1 Decays in 21Ne and 23Na: A Means of Identifying High Spin States?

Abstract

Pseudo-exact Force Constants for Tetramethyls of Group IVA Metals and Molecular Force Fields for Some Tetrahedral Molecules or Ions

Abstract

Untersuchung von Level-Crossing-Signalen an schnellen He-Atomen in inhomogenen Magnetfeldern / Investigation of Level-crossing Signals on High-velocity He-atoms in Inhomogeneous Magnetic Fields

Abstract

Population Density Measurements in a Partially Ionized Freejet Expansion Flow

Abstract

Delayed Emission from Green Algae “Chlorella pyrenoidosa” at Various Temperatures

Abstract

Excess Volumes of Mixtures of Acetone, Chloroform, Carbon tetrachloride, 1,4-Dioxane and Tetrahydrofuran with o-Dichlorobenzene

Abstract

Phase Diagrams of Binary Mixtures of Phenylenediamines and Dihydroxybenzenes

Abstract

A Covariant Semi-Classical Theory of the Radiating Electron

Abstract

Some Theoretical Considerations About the Excited Singlet and Triplet States of Diformamide and N-Methyl Diformamide

Abstract

Promptes und verzögertes Spektrum des reinen Dibenzofuran-Kristalls / Prompt and, Delayed Spectrum of the Pure Dibenzofuran-crystal

Abstract

Potentiom etrie Studies of the Lithium Interaction with Urea and N-Methylacetamide in Aqueous Solution

Abstract

The Photoelectron Spectra of Cyclopropyl Ketones

Abstract

Renormalization Group Approach to a One-Dimensional Cooperative T–e Jahn-Teller System

Abstract

Ion-Molekül-Reaktionen und Ladungsaustausch bei Stößen von O^– auf O₂ / Ion-Molecule Reactions and Charge Transfer in Collisions of O^– on O₂

⁸Li Emission in 1.8 GeV/c K^– -Meson Interactions in Nuclear Emulsion

Comparative FTR- and Ramanspectroscopic Studies of Fundamental Mode Frequencies in LiNbO₂ and the Present Limit of Oblique Phonon Dispersion Analysis

Hypersonic Velocity, Absorption and Relaxation in Molten C_SNO₃

NMR Investigation of Order Fluctuations, Self-Diffusion and Rotational Motions in the Nematic Liquid Crystal MBBA by T₁-Relaxation Spectroscopy

Systematic Patterns in the E1 Decays in ²¹Ne and ²³Na: A Means of Identifying High Spin States?