bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optically Thin Hydrogen Plasma with Self-Consistent Electron Velocity Distribution
Authors: Oxenius J. 
Published: February 2015

Abstract
Occupation numbers of the atomic levels and degree of ionization of a stationary optically thin hydrogen plasma are calculated for temperatures in the range 8000 °K ≲ T ≲ 16000 °K and for electron densities in the range 109 cm-3 ≲ ne ≲ 1017 cm-3. The electron velocity distribution is not supposed to be Maxwellian, rather, it is obtained in a self-consistent way from the corresponding kinetic equation which is solved simultaneously with the equations that describe the statistical steady-state of the atomic levels. Besides spontaneous radiative bound-bound transitions and radiative recombinations, inelastic electron-atom collisions as well as elastic electronelectron and electron-atom collisions are taken into account. Hydrogen atoms are approximated by model atoms having four bound levels and a continuum. The numerical results show that for temperatures T ≲ 10000 °K the tail of the electron distribution function differs markedly from that of a Maxwell distribution, except in the case of high electron densities. Likewise, the selfconsistently calculated values of the atomic occupation numbers and of the degree of ionization there deviate strongly, up to several orders of magnitude, from those obtained by assuming a Maxwellian velocity distribution of the electrons.
Calculation of the Force Acting on an Impurity in a Metal Submitted to an Electric Field or a Temperature Gradient
Authors: Gerl Maurice 
Published: February 2015

Abstract
Using the Bosvieux-Friedel polarization model, the charge carrier induced force on an impurity in a normal metal submitted to a temperature gradient or an electric field is calculated, and a connection is made between the two phenomena. The results are interpreted in terms of the specific resistivity and thermoelectric power of the impurity in the matrix.
A crude estimation of the force due to phonon scattering on an impurity in a temperature gra­ dient is given
Elektron-eiektron-doppelresonanz mit hilfe einer neuartigen mikrowellen-briickcn-anordnung
Authors: Vieth H. M. , Brunner H. , Hausser K. H. 
Published: February 2015

Abstract
A new type of X-band microwave bridge is described. It consists of a cavity and a helix arranged in an orthogonal manner in order to obtain maximal decoupling.
A variable frequency double resonance spectrometer com­prising this arrangement is used to measure ELDOR of free radicals in solution
Nonresonant Diffusion of Particles in Stochastic Fields
Authors: Biskamp D. , Pfirsch D. 
Published: February 2015

Abstract
A Fokker-Planck equation for the non-resonant scattering of particles by general weakly turbulent electromagnetic fields is derived using a simple quantum-mechanical method. The equation is compared with the corresponding weak turbulence equation as given e. g. in Kadomtsev's book and two applications are discussed.
Konzentrationslöschung durch Energieübertragung bei der Lumineszenz von Lösungen
Authors: Bojarski C. , Kuśba J. , Obermüller G. , Oberm G 
Published: February 2015

Abstract
Die Absorptionsspektren und Quantenausbeuten der Fluoreszenz von Rhodamin 6 G werden in zwei verschiedenen Wasser-Glycerinmischungen in Abhängigkeit von der Rhodaminkonzentration untersucht. Die beobachtete Konzentrationslöschung wird auf die Bildung von Rhodamindimeren zurückgeführt und die Abnahme der Quantenausbeute mit theoretischen Vorstellungen über die Kon­zentrationslöschung durch Energieübertragung zu den Dimeren verglichen.
Correlation Factor for the Diffusion of Charged Impurities in the Diamond Structure
Authors: Mehrer H . 
Published: February 2015

Abstract
The correlation factor for impurity diffusion by a vacancy-mechanism is a function of the vacancy-jump frequencies in the surroundings of the diffusing atom. Since in Si and Ge the vacancy can act as an acceptor, a long-range Coulomb interaction between donor atoms and vacancies exists. The usual assumption, that only a few vacancy-jump frequencies in the immediate surroundings of the vacancy are different from the jump frequency in the pure matrix, is not justified in this case.
A very general expression for the correlation factor of impurity-diffusion in the diamond structure is deduced. Vacancy-jump frequencies for jumps which originate from first-, second-, and third-nearest neighbours are treated explicitely. For more remote jumps the Coulomb force is taken into account as a drift force operating on the migrating vacancy. After specializing the general expression it is compared with the well-known ,,four-frequency-model" of Manning.
Interaction of 14.0 MeV-Neutrons with 12C in Stilbene
Authors: Fabian H.-U. 
Published: February 2015

Abstract
The pulse height spectrum of all heavy charged particles induced by 14.0 MeV neutrons in a 1" × 1" stilbene scintilla­ tor was measured using a pulse shape discriminator and the associated particle technique. The proton pulse spectrum was subtracted and the remaining alpha-pulse distribution is shown in a diagram. The sum of the cross sections for the reactions 12C (n, n') 3 α and 12C (n, α)9 Be was determined to be σc= (260±20) mb.
The Dissociation Energy of the Molecule PdGe
Authors: Peeters R. , Auwera-Mahieu A.M. Vander , Drowart J . 
Published: February 2015

Abstract
The dissociation energy of the molecule PdGe w as determined by the mass spectrometric Knudsen cell method: D0
0 (PdGe) =256.6± 12 kJ mol-1 (61.4 ± 3 kcal mol-1) .
Absolute Spin Assignments of Dy161 and Dy163 Neutron Resonances and the Hyperfine Coupling Constants in Dy163
Authors: Brunhart G. , Postama Hans , Rorer D.C. , Sailor V.L. , Vanneste L. 
Published: February 2015

Abstract
A method and equipment are described for measuring the spin dependence of slow neutron cross sections. The neutron beam from the High Flux Beam Reactor (HFBR) is polarized by Bragg reflection from a magnetized 92% Co-8% Fe single crystal which process also serves to select the neutron energy. Nuclei in the target are statically polarized in a field of ∼ 35 kOe at temperatures ranging from 0.05 to 0.10 K. Large nuclear polarizations are obtained in polycrystalline ferromagnetic dysprosium metal because of the large magnetic hyperfine interaction. The total angular momenta, /, of the compound states corresponding to the first several resonances in Dy161 and Dy163 were determined by measuring the transmission of the target with the neutron beam alternately polarized parallel and antiparallel to the nuclear polarization. Quantitative results at two resonances of opposite spin permit absolute /-value assignments (i. e., the assignments are independent of any knowledge of the absolute signs of the nuclear magnetic moments).
Results were as follows:
Isotope 163 161 161 161 161 161 161 161 161 163 161 161
E0 (eV) 1.71 2.72 3.69 4.35 7.75 10.40 10.87 12.65 14.3 16.25 16.7 18.5
J 2 3 2 2 3 2 3 2 (?) 2 3 (?) 2
The hyperfine interaction constants for Dy163, obtained by measuring the nuclear polarization as a function of temperature, were A/k = 0.100 ± 0.005 K, and P/k = 0.008 ± 0.001 K where A and P are, respectively, the magnetic and the electric hyperfine interaction constants.
Nuclear Gamma Resonance Study of the Ir —Fe and Ir —Ni Alloy Systems
Authors: Mössbauer R.L. , Lengsfeld M. , Lieres W. Von , Potzel W. , Teschner T. , Wagner F. E. , Kaindl G. 
Published: February 2015

Abstract
The Ir-Fe and Ir-Ni alloy systems were studied over the whole composition range by means of the nuclear resonance absorption of the 73 keV y-rays of 193Jr and of the 14.4 keV y-rays of 57Fe. The magnetic hyperfine field at the Ir-nuclei in Ir-Ni alloys decreases approximately linearly with the Ir concentration from - 460 kOe at 4.2 K in very dilute alloys to zero at about 20 at.-% Ir. This behaviour is paralleled by the decrease of the magnetic moment per Ni atom as determined from bulk magnetization measurements. The hyperfine fields at both Ir and Fe were measured for the ferromagnetic bcc phase of the Ir-Fe system. They turned out to be virtually independent of concentration with values of about -1400 kOe and - 330 kOe, respectively. Linewidths increasing with the Ir concentration indicate a distribution of hyperfine fields. The fee phase of the Ir-Fe system has been found to be paramagnetic at 4.2 K throughout the range of its existence. The dependence of the hyperfine fields on concentration is discussed in terms of a rigid 3d-band model combined with local shielding. A discussion of the concentration dependence of the 193Ir and 57Fe isomer shifts has to take into account lattice expansion as well as band repopulation effects.
hcp-Argoneinkristalle: Zucht und Messung der Doppelbrechung
Authors: Hagele W. , Probst W. , Dellian K. , Hingsammer J. , Lüscher E. 
Published: February 2015

Abstract
A procedure for growing hcp argon single crystals doped with oxygen is described. The hcp crystal structure is confirmed by birefingence and neutron scattering experiments. The birefringence at 77 °K of a hcp argon single crystal doped with 2% oxygen is determined to be ne-n0 = + (2.11 ± 0.63) · 10-6. From this result one can calculate the Lorentz field factors, obtaining fo = (333 328.6 ± 1.4) · 10-6 and fe = (333 342.7 ± 2.8) · 10-8. Using Ewald's theory of structural birefringence to determine σ = c/a from the measured birefringence yields σ = (163 451 ± 3) · 10-5. This value definitely excludes the ideal hcp structure (σ = 1.63299), in contrast with the results of X-ray measurements.
Investigation on the Primary Spins of the 235U Fission Fragments
Authors: Armbruster P. , Labus H. , Reichelt K. 
Published: February 2015

Abstract
The prompt γ-radiation emitted in 235U thermal fission has been investigated in a multiparameter experiment, γ-yield, time-distribution, energy spectrum and nuclear anisotropy of the emission have been measured, especially γ-yield and anisotropy as a function of fragment mass and γ-energy. The mass dependence of the primary spins of the fragments can be deduced from these measurements. A value of 7 h̶ for the average primary spin and an increase of the primary spins within each fission product group is obtained. This dependence is explained within an adiabatic model of scission due to the mass dependence of the deformation of the fragments.
Electron Paramagnetic Resonance Study of Copper (II)-tetrammine Nitrate in Solution
Authors: Vierke G. 
Published: February 2015

Abstract
The electron paramagnetic resonance of copper (II)-tetrammine nitrate in solution of methanol and water has been investigated. The data obtained from the spectra at room temperature and 97 °K together with the optical transition energies determined from single crystal polarized absorption spectra at 77 °K by other authors were used to calculate the LCAO-MO bonding parameters. The bonding orbital of the ammonia molecule cannot be described by the concept of sp2 hybridization which was exclusively used in the theory. Therefore a calculation of the overlap integral S(n) for α bonding and of the superhyperfine splitting was carried out in terms of an arbitrary hybridization parametern. For ammonia, n was taken from the Duncan-Pople hybrid wave function for the lone pair orbital. The o bonding and the out-of-plane π bonding appear to have a moderate degree of covalency (α = Ϭ = 0.91; α’= 0.49). The covalent in-plane n bonding is somewhat stronger (β = 0.87) but is by no means so strongly covalent as is observed in compounds with ligands which do not exclusively coordinate through the lone pair electrons.
At low temperature nine ligand nuclear superhyperfine structure lines corresponding to the interaction of four magnetically equivalent nitrogen nuclei have been observed. The value of α' derived from the superhyperfine splitting is in excellent agreement with that obtained from the copper nucleus hyperfine structure.
Streumessungen am System LiCs und das Singulett-Potential dieses Moleküls / Total scattering Cross Section Measurements for LiCs and the Singlet Potential of this Molecule
Authors: Kanes H. , Pauly H. , Vletzke E. 
Published: February 2015

Abstract
The velocity dependence of the total collision cross section has been measured for the system LiCs in the energy range from 15-1000 eV. Using the observed glory undulation together with spectroscopic data a potential for the singlet ground state of LiCs is proposed.
Image Converter and Intensiner Investigations on Luminous Fronts (Ionizing Waves) in Nitrogen Discharges in a Homogeneous Field
Authors: Koppitz J. 
Published: February 2015

Abstract
In this paper optical space and time resolved measurements on the later development of Kanal (streamer) and Townsend discharges in nitrogen are treated. In both discharges fast luminous fronts (the so called ionizing waves) arise: in the streamer discharge between the primary streamer stage and the spark stage, and in the Townsend discharge during the transition to the glow.
For the streamer discharge new experimental results are given, especially at high overvoltages. In the case of the Townsend discharge the development of an idealized, nearly one dimensional dis­charge is treated. The experimental results are in good agreement with theoretical considerations. In contrast to this idealized discharge often strong constrictions are found during the development to the glow, so that the discharge becomes nearly filamentary. The reasons for this behaviour are discussed and the way to avoid it.
Notizen:Ein Experiment zur retrograden Bewegung von Lichtbögen
Authors: Bartels Klaus 
Published: February 2015

Abstract
Eine elektrische Bogenentladung bewegt sich in einem transversalen magnetischen Feld senkrecht zu diesem Feld und zur Stromrichtung. Im allgemeinen erfolgt diese Bewegung im Sinne der Ampereschen Re­ gel, bei niedrigem Druck jedoch kann sich der Bogen in entgegengesetzter, "retrograder" Richtung bewegen. Zur Deutung dieser retrograden Bewegung eines freibrennenden Lichtbogens wurde eine Reihe von Hy-* Sonderdruckanforderungen an Seminar für Didaktik der Physik, Pädagogische Hochschule Ruhr, Abteilung Essen, D -4300 Essen, Henri-Dunant-Straße 65. 1 Eine Übersicht findet man in A. E i d i n g e r u . W. R i e d e r , Arch. Elektrotechnik 43, 94 [1957].
Notizen:Allgemeine Aussagen über Aktivitätskoeffizienten bei Elektrolytschmelzen
Authors: Haase R. 
Published: February 2015

Abstract
Wir betrachten eine flüssige Mischung, die aus zwei Elektrolyten mit je zwei Ionenarten besteht. Dabei soll eine Ionenart den beiden Elektrolyten gemeinsam sein. Reispiele stellen die Salzschmelzen N aN 03-f AgNOs und PbCl2 + PbBr2 dar. An Hand dieses relativ ein­ fachen Typs von binären Elektrolytschmelzen, der schon vor kurzem1 hinsichtlich der Transporteigenschaften untersucht worden ist, sollen einige thermodynamische Gesetzmäßigkeiten abgeleitet und diskutiert werden. Diese betreffen die Abhängigkeit der Aktivitätskoeffi­ zienten von der Zusammensetzung sowie die Beziehun­ gen zwisdien den Aktivitätskoeffizienten der einzelnen Teilchenarten und denen der Komponenten. Obwohl man heute, auch bei der Thermodynamik der Elektro­ lytschmelzen, in zunehmendem Maße zur Beschreibung durch "Zusatzfunktionen" übergeht2, ist das hier zu besprechende Problem in Zusammenhang mit einer all­ gemeinen Formulierung der Grenzgesetze für unend­ liche Verdünnung wichtig. Molekularstatistisch sind ja die primären Einheiten nicht die Komponenten oder ionischen Bestandteile, sondern die wirklich vorhande­ nen Teilchenarten. Die beiden Elektrolyte der binären Schmelze werden als Komponente 1 und Komponente 2 bezeichnet. Die­ jenige Ionenart, die nur in der Komponente 1 bzw. 2 vorkommt, wird Teilchenart a bzw. b genannt. Die den beiden Komponenten gemeinsame Ionensorte heißt Teil­ chenart c. Die Zahl der Ionen der Sorte a bzw. b, die aus einem Molekül der Komponente 1 bzw. 2 bei der Dissoziation hervorgehen, wird mit r a bzw. vb bezeich­ net, während das Symbol vc bzw. vc' die Zahl der Ionen der Sorte c bedeutet, die aus einem Molekül der Kom­ ponente 1 bzw. 2 stammen. So gilt etwa für die Salz­ schmelze N aC l(l) +M gC l2(2) : n = ^Na+ = 1,
Notizen:Anisotropie der 195Pt-KMR-Verschiebungen kristalliner Platin(II)-Verbindungen
Authors: Keller H. J. , Rupp H. H. 
Published: February 2015

Abstract
Wie wir bereits kürzlich am Beispiel des kristallinen K2PtCl4 zeigen konnten1, tritt bei quadratisch koordi­nierten Platinkomplexen eine Anisotropie der chemi­schen Verschiebung des 195Pt-KMR-Signals in der Grö­ßenordnung von 1% auf. Um den Einfluß von im Sinne der "spektroskopischen Reihe" verschieden starken Li­ganden auf die magnetische Anisotropie zu überprüfen, haben wir nun zusätzlich Kristalle der Verbindungen (2) - (4) der Tab. 1 untersucht.
Fluorescence Investigations on Intramolecular Energy Transfer in Alkyl-Fluorenole and Alkyl-Anthracene
Authors: Fick E. , Herler H. , Heusinger H. 
Published: February 2015

Fluorescence investigations of alkyl fluorenole- and alkyl anthracene-solutions in n-hexane or cyclohexane resp. were performed for β- and UV-excitation. The observed influence of scavengers for electrons or positive ions on the fluorescence intensity for β-excitation reveals that charge trans­fer is the predominant process for the intermolecular energy transfer from solvent to solute.
The fluorescence intensity of alkyl fluorenoles and alkyl anthracenes increases with increasing number n of CH2-groups in the alkyl chain, reaching a plateau for n ~ 6. This gives evidence for intramolecular energy transfer within the CH2-Chain with a limited range. Using a simple model in alkyl fluorenoles for the transfer probability from Cn to Cn-i in the chain a value of 0.65 could be deduced. The model derived for n-alkyl fluorenoles fits to the values of branched alkyl fluorenoles as well.
The results obtained from the fluorescence measurements are compared with those on C - H- bond breakage in the aliphatic chain, derived from investigations of hydrogen production and ra­dical formation. Possible mechanisms for intramolecular energy transfer are discussed.
Einfluß von Fehlstellen und Verunreinigungen auf den Ordnungs-Unordnungs-Übergang im hexagonalen Eis Ih
Authors: Sesselmann I. , Helmreich D. 
Published: February 2015

Abstract
Die Temperaturabhängigkeit der longitudinalen elastischen Konstanten c33 von reinem und c33HF von HF-dotiertem schweren Eis wurde im Bereich zwischen 80 und 200 °K mit einer Phasenvergleichstechnik gemessen. Beim HF-dotierten D2O-Eis wurde unterhalb 150 °K eine positive Anomalie gefunden. Reines D2O-Eis verhält sich im gemessenen Temperaturbereich normal.
Die Ergebnisse können erklärt werden durch mikroskopische, im Hochtemperaturbereich stabile Keime der Tieftemperaturphase, die beim Abkühlen Zentren der neuen Phase werden.
The Specific Heat of Pure and Doped Ice Near 120 °K
Authors: Pick M. A. , Wenzl H. , Engelhardt H. 
Published: February 2015

Abstract
. The specific heat of pure and doped ice Ih single crystals was measured from 80°K to 230 °K with a differential heat-fiux calorimeter. In the region near 120 °K the specific heat exhibits a positive anomaly which is explained by a partial ordering of the ice.
Thermally Stimulated Currents in the Range of Unity Gain Factor
Authors: Bragagnolo J. A. , Dussel G. , Böer K. W. , Dussel G. A. 
Published: February 2015

Abstract
Thermally stimulated current-curves in CdS platelets with slit electrodes change their character when the photoelectric gain-factor increases above one. Here the photocurrent remains essentially frozen-in up to temperatures at which marked thermal quenching sets in. A positive space charge region is assumed to be responsible for the frozen-in photocurrent. A reliable TSC-analysis of the trap distribution can be conducted only for gain factors considerably below one.
The Concept of Reversibility and Irreversibility in Thermostatics
Authors: Schröter Joachim 
Published: February 2015

Abstract
First a general definition of reversibility is given which is in accordance with the mechanical concept of reversibility. This definition is applied to thermostatics. It is shown that the smooth curves in the space of equilibrium parameters can be approximated arbitrarily by irreversible or by almost reversible real processes. The work done during an almost reversible process is given by a Pfaffian form. The converse is also true. If the differential work is given by a Pfaffian form the processes are practically reversible. Finally the uniqueness of a Pfaffian form is shown, if it is used as differential work.
Impedances of Warm Plasmas near the Lower Hybrid Resonance
Authors: Babu R. , Schlüter H. 
Published: February 2015

Abstract
With full electromagnetic treatment electron pressure effects are included in the calculation of plasma impedances and power transfer to a plasma cylinder in the domain of the lower hybrid resonance. The general results are applied to cases of interest in radio frequency discharges with azimuthally symmetric excitation and zero coil-plasma-gap. For these specific situations the effects of electron pressure are found to be small.
Thermodynamik heterogener Gasgleichgewichte II. Gasphasenzusammensetzung und chemische Transportreaktionen in den Systemen Wolfram — Halogen (Fluor, Chlor, Brom)
Authors: Neumann G. M. , Gotschalk G. 
Published: February 2015

Abstract
Zur Beurteilung der Frage nach der Möglichkeit und der Richtung eines chemischen Transportes von Wolfram in den Wolfram-Halogen Systemen bei Vorliegen eines Temperaturgradienten werden die Gleichgewichtszusammensetzungen der Heterogensysteme berechnet. Die Berechnungen werden mit Hilfe von Computerprogrammen für die mit Wolfram als Festkörper koexistierende Gasphase für Temperaturen von 500-bis 3600 °K und für Halogen-Anfangsdrucke von 1 -10-6 atm durchgeführt.
Aus der Temperaturabhängigkeit der Massenbilanz des Wolframs ergibt sich die prinzipielle Möglichkeit von Transportreaktionen in diesen Systemen. Von besonderem Interesse ist die Umkehr der Transportrichtung, die für die einzelnen Wolfram-Halogen Systeme charakteristisch ist.
Die Ergebnisse der Berechnungen werden durch experimentelle Beobachtungen bestätigt.
The Use of the Modified Extended Hiickel Method in the Dynamics of Molecules Containing Multiple Bonds
Authors: Yeranos Walter A. 
Published: February 2015

Abstract
Using the acetylene, ethylene and ethane series, the applicability of the Modified Extended Hiickel Method in the determination of the atomization energies as well as stable configurations of molecules has been demonstrated. It is believed, moreover, that within the procedual framework of our proposed technique the proportionality constants Fσ (HH) =2.00, Fσ (CH) =1.75, Fσ (CC) = 2.10 and Fπ (CC)=1.45 should prove adequate in the semi-empirical study of the atomization energies, stable configurations (and potential barriers) of all the hydrocarbons, be they aliphatic or aromatic.
MOS-Sandwich-Gitter-Diode zur Erzeugung von Feldionisationsfeidstärken an der Phasengrenze Festkörper/Gas
Authors: Gentsch H. , Prüller H. 
Published: February 2015

Abstract
The sandwich grid diode is a new means of producing extremly high elektrical fields at a solid surface. The ability to ionize gases and to produce field electrons with such a thin film system permits an estimate of the maximal field strength. It is interesting to note, that with this diode one can produce fields higher than 5-107 V/cm in gases up to atmospheric pressure without the risk of a discharge. This fact may become of some importance for the study of field induced desorption and catalysis.
Aktivitätskoeffizienten bei Salzschmelzen mit drei Komponenten
Authors: Richter Joachim 
Published: February 2015

Abstract
The activity coefficients of molten salts with three components will be defined, and the logarithms of these activity coefficients will be represented as power series in the mole fractions of the two other components with integral exponents. Power series with three empirical parameters have proved useful as first approach for low molecular nonelectrolyte solutions, and they also describe the activity coefficients of a ternary melt adequately. In the appendix a general formula will be given for the activity coefficients of a melt composed arbitrarily containing water as an additional com­ponent.