bluuebunny/crossref_metadata_2025 huggingface dataset:
Mischungswärmen und Verbindungsbildung in binären flüssigen Systemen
Authors: Becker F. , Fries E. W. , Kiefer M. , Pflug H. D.
Published: February 2015

The heats of mixing of binary liquid systems with strong specific interactions are treated by means of simple equilibrium models based on the concept of the ideal associated solution. In this paper unsymmetrical heat-of-mixing curves Hᴍ = f(NA
0) are analysed in terms of two different twostep equilibrium models, i . e . A+2 B ⇄ AB2 (I), and A+B2 ⇄ AB+B (II). Iterative calculation methods for determining the four equilibrium parameters from experimental data are given, including approximative methods for obtaining an initial set of these parameters. The method is applied to new experimental data on the systems (1) tetrahydrofurane-chloroform, (2) methyl isobutyl ketone-sulphuric acid, and (3) pyridine-chloroform, obtained at 25° by a continuous enthalpy titration method. It is shown that the data of the systems (1) and (2) can be very well fitted by the equations of model (I), whilst model (II) is valid for the system (3). Complete thermodynamic data for all three systems are given, and the reasons why these systems fulfil the assumptions of the two-step equilibrium models are discussed.
Nachweis von organischen Molekülkomplexen über deren negative Ionen
Authors: Knof Hans , Kraft Dieter
Published: February 2015

Molecular polymeres of organic compounds could be identified with a special mass spectrometer by their negative ions without fragmentation from acetone, methanol, and formic acid. Verification of these measurements was obtained by the investigation of deuterated samples. Molecular ions were measured up to trimers. Benzene and cyclohexane did not show polymer ions. The measured pressure dependence indicates preference of electron attachment in ion production against ion molecule reactions. The complexes are held together by the intermolecular dipole forces.
Der Debye-Sears-Effekt zur Bestimmung der elastischen Konstanten von Silicium
Authors: Metzger H. , Kessler F. R.
Published: February 2015

Der Debye-Sears-Effekt (Lichtbeugung an Ultraschallwellen) wird als Methode zur Bestimmung der elastischen Konstanten auf den nahen ultraroten Spektralbereich ausgedehnt und auf Silicium angewendet. Als Lichtquelle dient ein He-Ne-Gaslaser mit einer Wellenlänge von 1,1523 μm. Die Ultraschallfrequenz liegt bei 57 MHz.

Für die Intensitätsverhältnisse des gebeugten Lichtes läßt sich die Raman-Nathsche Theorie des Phasengitters benutzen; hieraus können die vorliegenden Brechungsindexschwankungen bestimmt werden.

Die 7 kristallographisch verschiedenen Schallgeschwindigkeiten bzw. die 3 elastischen Konstanten des Siliciums werden angegeben und den aus Impulsmeßverfahren bekannten Literaturwerten vergleichend gegenübergestellt.

Aus der Resonanzverstimmung bei optisch gemessener Temperaturerhöhung gelingt es, die Temperaturkoeffizienten der Schallgeschwindigkeiten zu messen und daraus die Temperaturkoeffizienten der elastischen Konstanten zu berechnen.
Temporal Development of Giant Pulses in Passively Q-switched Laser Oscillators
Authors: Darée K. , Puell H.
Published: February 2015

The development of giant pulses in a passively Q-switched laser oscillator has been investigated in the case of a high power, multimode system. An experimental technique is described which allows the study of the pulse development over more than two decades of laser power. For powers ≲ 0.1 maximum power an exponential increase of light flux is found. The time constant of this exponential part is calculated, and the relevant parameters are discussed. Calculated and measured time constants are in satisfactory agreement. In addition, it is shown that there is a connexion between the risetime of the pulse and the output energy, power, and divergence of the laser beam. As an example, the optimalization of a laser system for microplasma production is considered.
Spektroskopische Untersuchung von Hetero-Excimeren mit heterozyklischen aromatischen Kohlenwasserstoffen als Elektronakzeptoren
Authors: Rehm Dieter
Published: February 2015

Heterocyclic aromatic hydrocarbons form hetero-excimers with electron donors. The correlation which exists between the energy corresponding to the complex emission maximum and the redoxpotentials of acceptors and donors shows that charge-transfer interaction is predominant in these hetero-excimers.

For some complexes the thermodynamic parameters of complex formation as well as the dipole moments in the excited state are reported.
Microwave Relaxation and Association of 3,5 Dimethyl 3-Hexanol
Authors: Hanna F. F. , Abd-El-Nour K. N.
Published: February 2015

The dielectric constant (ε′) and dielectric loss (ε′′) of 3,5 dimethyl 3-hexanol in heptane have been measured for dilute and concentrated solutions at five wavelengths between 25 cm and 2 mm and at 20°, 40° and 60 °C. The data have been analysed and two relaxation times are obtained. The long relaxation time is attributed to the rotation of the whole molecule and the short relaxation time to the relaxation of the OH-group. For the range of concentrations used, the results show that associates are hardly detectable.
Berechnung der Elektronendichte von Alkanen nach dem S-DIAG-Verfahren zur Interpretation chemischer Verschiebungen
Authors: Janoschek R.
Published: February 2015

Mit dem nichtempirischen Verfahren S-DIAG werden unter Verwendung sphärischer Gauß-Funktionen die Elektronendichten an den Kohlenstoffkernen und an den Protonen einiger Alkane berechnet. Im Gegensatz zu semiempirischen Verfahren liefern die hier berechneten Elektronendichten im Gang vollkommene Übereinstimmung mit den gemessenen chemischen Verschiebungen.
Quantitative Zerlegung binärer Legierungsschmelzen in verschiedene Strukturanteile /A Method for Quantitative Subdivision of a Two-Component Melt or a Two-Component Amorphous Substance Into Their Structural Constituents by Diffraction Experiments
Authors: Steeb S. , Bühner H . F .
Published: February 2015

Based on the experimental fact that the average coordination number in a binary liquid alloy is not constant, a refined model for the structure of such melts consists of two structural fractions: a) one which shows the same partial coordination number as the relevant solid intermetallic compound and

b) the other, in which the atoms of both kinds are distributed at random. The application of this model to previous X-ray diffraction measurements on Mg -Sn, Mg -Pb, Mg -Ag, and Au-Al alloys permits to subdivide the respective melts into the structural fractions mentioned above.

The partial concentrations are plotted vs. the total concentrations. Finally, it is pointed out that the same method may be employed to determine the crystalline fraction in amorphous solids and in liquid semi-conductors quantitatively.
Adsorption von CO auf einer Palladium(111)-Oberfläche
Authors: Ertl G. , Koch J.
Published: February 2015

The adsorption of CO on a clean Pd(lll) surface has been studied by means of low energy electron diffraction (LEED), contact potential measurements and flash desorption. At coverages ㊀ between 1/3 and 1/2 ordered adsorption phases are observed for which structure models are derived. The maximum increase of the work function Δϕ is about 1 eV; Δϕ is proportional to ㊀. Adsorption isotherms have been measured between 100 and 300 °C and the isosteric heat of adsorption Ead has been determined as a function of ㊀. Ead is constant (34 kcal/mole) up to ㊀ = 1/3 and then decreases owing to structural influences and intermolecular interactions.
Die Ionisierungsquerschnitte von Stickstoff-und Halogen-Kohlenwasserstoffderivaten
Authors: Grosse Hans-Jörg , Bothe Hans-Karl
Published: February 2015

Mit einem 1968 beschriebenen Ionisierungsquerschnittsdetektor mit Kr85 -β-Strahlenquelle wurden die relativen Werte der Ionisierungsquerschnitte von Stickstoff-und Halogen-Kohlen-wasserstoffderivaten bestimmt. Führt man empirisch bestimmte "Bindungsquerschnitte" analog zu der früheren Arbeit1 ein, so stimmen die aus „Bindungsquerschnitten“ berechneten Ionisie-rungsquerschnitte innerhalb des Meßfehlers von 2% mit den gemessenen überein. Ein Vergleich der experimentell ermittelten Werte mit den nach den Verfahren von OTVOS und STEVENSON2 (1956), LAMPE, FRANKLIN und FIELD3 (1957) und STEVENSON und SCHISSLER4 (1961) berech-neten Daten zeigt, daß die Methode von OTVOS und STEVENSON zwar die günstigste Übereinstim-mung für eine Reihe von Verbindungen ergibt, die maximale Abweichung bezüglich des experi-mentellen Ionisierungsquerschnittes bei stickstoff-und halogenhaltigen Kohlenwasserstoffderiva-ten jedoch 11,5% bzw. 14,7% beträgt. Die Ursache dieser Abweichungen im Gegensatz zu den aus „Bindungsquerschnitten“ erhaltenen Ionisierungsquerschnitten ist auf die Vernachlässigung des Einflusses der chemischen Bindung auf die Größe des Ionisierungsquerschnittes zurück-zuführen. Die Größe der „Bindungsquerschnitte“ und ihre Anwendungsgesetze können mit Hilfe der Ultraviolett-Absorptionsspektren erklärt werden.
Unelastische Elektronenstreuung an 140Ce bis 3,5 MeV Anregungsenergie
Authors: Pitthan R.
Published: February 2015

From electron scattering experiments (scattering angle 141°, primary energies 60 and 50 MeV) ground state radiation widths were determined for the levels at 1.60 (2+), 2.08 (4+), 2.46 (3-), 2.90, 3.12, and 3.32 MeV.

Spins and parities of the last three levels which were known as 1+ or 2+, could be classified as 2 +.
Band Structure in the Excitation Spectrum of Type II Superconductors
Authors: Schattke W
Published: February 2015

The periodic structure of the mixed state leads to some band splitting in rough analogy to the electrons in a metal. The density of states for tunneling perpendicular to the flux lines shows an appreciable depression at energies ħω ≈ (ħ2/2m) kF|l|, l being a reciprocal lattice vector of the flux lattice normal to the tunneling surface.
Self-diffusion in Molten Silver Iodide
Authors: Andréasson Dan , Behn Anders , Sjöblom Carl-Axel
Published: February 2015

The self-diffusion coefficients of the cation (D+) and of the anion (D-) have been measured in molten silver iodide be­ tween 580 °C and 620 °C with the porous-frit technique. At 610 °C it is found that D+ = D-=5A × 10-5 cm2 s-1. At the melting point (556 °C) D+ melt (4.4 × 10-5 cm2 s-1) is very close to D+ solid (4.3 × 10-5 cm2 s-1) . The Klemm friction coefficients do not indicate the existence of complex entities. D+ and D- calculated according to the Nernst-Einstein equation agree with observed data within 20%.
Lorentz-und metrikinvariante Skalare
Authors: Fleischmann R.
Published: February 2015

Auf die Sonderstellung der metrikinvarianten (universell gequantelten) Skalare der Physik wird hingewiesen. Aus ihnen können die übrigen Größen definiert werden mit Hilfe von Länge und Zeit. Eine bevorzugte Stellung haben die alternierenden Differentialformen, weil sie sich als Ganzes wie metrikinvariante Skalare verhalten. Der Begriff orthogonal geht nicht ein.
Das Kernniveauschema von Yb 175
Authors: Breitig Dieter
Published: February 2015

The Yb174 (n,γ) -spectrum has been measured in the energy region of 26 -1500 keV. More than half of the observed 239 y-lines were placed in a level scheme. Precise energies have been determined for the states and their deexcitation has been studied in detail. New rotational bands, with the configurations { ([624 ↑]n + [512 ↑]n + [514 ↓]n)3/2 +[642 ↓]}, [651 ↓] and [642 ↓] are proposed at 1067, 1356 and 1937 keV. Calculations show that these bands strongly mix through Coriolis coupling. Additional and previously unknown states of the [624 ↑] and [633 ↑] bands are proposed. Level energies and y-branching ratios are explained reasonably well through a multi­ band mixing calculation of the configurations with negative parity.
Absolutbestimmung der kohärenten Streuamplitude von Schwefel und der totale Wirkungsquerschnitt für subthermische Neutronen
Authors: Trüstedt W.D.
Published: February 2015

Die Bestimmung der kohärenten Streuamplitude des gebundenen Schwefelatoms mit Hilfe des Neutron-Schwerkraftrefraktometers des Forschungsreaktors München ergab a = (2,847 + 0,001) F. Der totale Wirkungsquerschnitt von flüssigem Schwefel (135 °C und 176 °C) für Neutronen- Energien 4 · 10-3 > E > 0,15 · 10-3 eV wurde gemessen. Der Beitrag der Selbstdiffusion des Schwefels zum inelastischen Streuquerschnitt wird beredinet.
Hochenergetische Konversionselektronen und das Niveauschema von 200Hg
Authors: Mampe W. , Egidy T. von , Kaiser W. , Schreckenbach K.
Published: February 2015

Approximately 165 conversion electron lines from slow neutron capture in 199Hg have been measured with the beta spectrometer at the reactor FRM between 900 keV and 8 MeV. The high energy K-conversion coefficients of El and Ml transitions are separated distinctly and agree very well with theoretical calculations, which have been performed by several groups recently. High energy L-conversion electron coefficients have been measured for the first time with such a degree of accuracy that different multipole orders are separated and a comparison with theoretical values is possible. 6 known levels above 2 MeV have been assigned 1+ and 14 new levels have been established. 145 lines have been placed into the level scheme and new level energies have been calculated. A new 0+ level has been found at 1856.97 ± 0.1 keV.
Die plötzliche Kernladungsänderung als Anregungsmechanismus optischer Übergänge
Authors: Luchner K. , Parsche H. , Micklitz H.
Published: February 2015

The sudden change of nuclear charge (β-decay) produces a finite probability for the excitation of the outer electron shell. The emission spectrum of a gaseous Xe133-source exhibits light from the daughter Cs+, excited by the sudden change of nuclear charge, as shown by a spectral analysis. The probability for this excitation, p ∼ 6 · 10-2 per β-decay, is found in coincidence with the β-particles from the upper part of the β-spectrum; this value is lowered if also the low-energy part of the β-spectrum is included in observation; this seems to indicate a breakdown of the sudden approximation around 20 keV. The absolute values of p for Kr85 and Xe133 are discussed. The photon yield from the Kr85-decay in solid state for high Eβ is not a constant, as it is in the gaseous state, but decreases with Eβ , suggesting nonradiative transitions induced by the β-recoil.
Cross Section for "Ultracold" Neutrons I. Theory of Magnetic Scattering
Authors: Binder K.
Published: February 2015

Very cold neutrons (typical wavelengths are about 102 Å) are available by recently developed techniques 2. The features of the scattering of these “ultracold” neutrons are investigated in the present paper discussing a few examples of magnetic scattering. The diffraction of neutrons by the vortex lattice in superconductors is treated as an example of elastic scattering, while in most other cases the scattering is inelastic. We discuss the scattering by ferromagnetic magnons at low temperatures and the critical scattering from an isotropic ferromagnet above the critical tempera­ture. Simple models are used to derive the total cross sections. It is shown that relevant information about the inealsticity can be gained by the measurement of total cross sections in these cases.
Präzise Messung der totalen Wirkungsquerschnitte von Wismut, Blei, Silizium und Kohlenstoff für 130 eV-Neutronen
Authors: Dilg W. , Vonach H.
Published: February 2015

A precise transmission measurement of the cross sections of Bismuth, Lead, Silicone and Carbon for 130 eV neutrons (Co-resonance) has been carried out. A new resonance method has been applied, using epithermal reactor neutrons, which have been scattered twice from Co-foils. - We obtained the total 130 eV cross sections: Bi: 9,182 ± 0,007 b, Pb: 11,295 ± 0,009 b, Si:2,0442 ± 0,0018 b, C: 4,746 ± 0,007 b. From these results the coherent nuclear scattering lengths (bound), Bi: 8,646 ± 0,005 fm, Pb : 9,524 ± 0,004 fm, C: 6,660 ± 0,006 fm, have been calculated, under consideration of various corrections (absorption, Schwinger-scattering, Incoherence, Neutron-Electron-Interaction, energy-dependence of nuclear-scattering).
Untersuchung des Neutroneneinfang-Mechanismus in der Reaktion 80Se(n,γ)81Se und der Kernstruktur von 77Se, 78Se und 81Se mit Hilfe von (n,γ)-Reaktionen / Neutron Capture Mechanism in the Reaction 80Se(n,γ) 81Se and Nuclear Structure of 77Se, 78Se and 81Se, Studied In The (n,γ) -Reaction
Authors: Rabenstein D. , Vonach H.
Published: February 2015

Gamma radiation from the capture of neutrons in natural Se and in enriched 76Se and 80Se has been studied with different Ge (Li)-detectors, with a Ge(Li)-NaJ pair spectrometer and with a Ge (Li) -Ge (Li) two-paramater γ-γ coincidence system. These measurements resulted in a considerable improvement of the level schemes of 77Se, 78Se and 81Se. The 81Se and the 107Ag level schemes are compared, and the applicability of phonon-particle coupling to low-lying states of 81Se is discussed. In the case of 77Se, some properties may be possibly better described by the Nilsson model. It is rather clear, however, that both models can only be regarded as limited approximations and that more refined models are required for Se nuclei.

The well-known, unusually small isomeric cross section ratio of 81Se, and the weak population of p-single-quasiparticle states by primary transitions from the capture state 80Se + n, which shows up in our measurements, may be understood by assuming a capture state containing a doorway state with a simple collective excitation.
Investigation of Lithium Precipitates in Germanium Crystals by Anomalous X-Ray Transmission
Authors: Wenzl Helmut F.
Published: February 2015

The precipitation of lithium dissolved in germanium crystals and the re-solution of the precipitates during heating has been studied by means of anomalous transmission of x-rays. The effective absorption coefficient depends sensitively on the spacial distribution of lithium interstitials, and is enhanced enormously if pair correlations increase, as is the case during clustering. On the basis of Dederidis' theory and knowledge about the Geli phase diagram, the experiments provide relations between concentration and radius of the precipitates, distortion parameters, and average and local concentration of lithium interstitials.
Untersuchung der Wendelinstabilität an einem wandstabilisierten Wasserstoffbogen
Authors: Mentel Jürgen
Published: February 2015

The formation of a steady helical instability in a wall-stabilized hydrogen arc at low currents is investigated experimentally. To determine the onset-point of the instability theoretically the basic equations of electrodynamics and the balance of mass, momentum and energy are solved in the limiting case of vanishing growth-rate of the instability, taking into account the dissipative terms as well as the temperature dependence of the density. It turns out that the destabilizing J X B-forces, which try to deflect the arc by a convective heat-transfer, are balanced by the thermal stabilization of the tube-wall as well as by the unsym metrical energy-production in the curved arc. Onset-point and pitch of the helix result from the theory in full agreement with the measurements.
Kraftkonstanten der Siliciumtetrahalogenide und Schwingungsberechnungen an Chlorbromsilanen SiClnBr4–n
Authors: Höfler Friedrich
Published: February 2015

Ausgehend von den nach verschiedenen Verfahren erhaltenen Kraftfeldern von SiF4 und SiCl4 werden für SiBr4 und SiJ4 Kraftkonstantensätze angegeben. Zur Berechnung der Grundschwingungen von SiCl3Br, SiCl2Br2 und SiClBrs eignen sich Kraftkonstanten, die direkt oder nach geeigneter Mittelung bzw. Abstufung von SiCl4 und SiBr4 übertragen werden. Eine Neuaufnahm e des Raman- Spektrums von SiClBr3 ergibt, daß ν6 in Übereinstimmung mit der Berechnung bei 161 cm-1 liegt.
Berechnung der elektrostatischen Wechselwirkungsenergie für ein Kristallgitter zylindersymmetrischer Teilchen
Authors: Neckel A. , Kuzmany P. , Vinek G.
Published: February 2015

A method is presented for the calculation of the electrostatic interaction energy in a crystal lattice taking into account the real charge distribution of the particles. For this purpose the charge distribution of a particle is represented by a superposition of multipole moments. The crystal potential is expanded into amultipole expansion, the resulting lattice sums being evaluated according to Ewald's method. The present paper is restricted to the treatment of molecules or molecule-ions of cylindrical symmetry.
Berechnung der Gitterenergie der Alkalihydrogenfluoride KHF2, RbHF2 und CsHF2
Authors: Neckel A. , Kuzmany P. , Vinek G.
Published: February 2015

In the paper of Neckel , Kuzmany , and Vinek5 a procedure was proposed for the calculation of the electrostatic interaction energy of a crystal lattice provided the multipole moments of the particles are known. In the present paper a method for calculating multipole moments using LCAO-MO-wave functions is discussed. The multipole moments for the [FHF]--ion and the Madelung energy of KHF2 , RbHF2 and CsHF2 are evaluated. The results are com pared with calculations obtained by using a point charge model. For KHF2 , RbHF2 and CsHF2, the total lattice energies are evaluated.
Quasi-elastic Scattering of Neutrons for the Study of Random Motions in Solids
Authors: Stiller H. , Springer T.
Published: February 2015

Investigations on motions of hydrogen atoms in metals, on rotational diffusion in molecular solids and on fluctuations of protons at hydrogen bonds are reviewed as examples for experiments with incoherent neutron scattering requiring high resolution.
The Conductance of the Alkali Halides I. Sodium Chloride in Sulfolane-water Mixtures, at 25 °C and 35 °C
Authors: Castagnolo M. , Jannelli L. , Petrella G. , Sacco A.
Published: February 2015

Abstract The electrochemical behaviour of sodium chloride in water-sulfolane mixtures, at 25 °C and 35 °C, was investigated, the concentration of the salt ranging within (1÷7)·10-3 moles/liter and the dielectric constant (D) of the solvent mixtures within 78 and 44.

Analyzing the data by the Fuoss, Onsager and Skinner treatment, Λ0, aL, A , aA and Λ0 η values were obtained. At both temperatures, Λ0 is a smooth function of the solvent compositions; a re­markable association seems evident at D < 60 ; log A vs. 1/D plots are linear; the contact distances

of the ions are lower than in other isodielectric media.

Except for a limited region close to pure water, the Walden product Λ0 η is constant (1.20 at

25 °C and 1.19 at 35 °C) in the whole solvent composition range.
Schwingungs-und Kernresonanzspektren von Trijodsilan und gemischten Trihalogensilanen
Authors: Hengge E. , Hofler F.
Published: February 2015

Die aus den Raman-Spektren erhaltenen Grundschwingungen von HSiJ3 , HSiClJ2 (I), HSiCl2J (II), HSiBrJ2 (III) und HSiBr2J (IV) sowie von SiBr2J2 und SiBrJ3 werden mitgeteilt. Die Zuordnung erfolgt nach spektralen Übergängen und wird durch Kraftfelder gesichert. Die bisher unbekannten Mischhalogenide I - IV entstehen durch Äquilibrierung von HSiJ3 und HSiCl3 bzw. HSiJ3 und SiBr4; sie werden auch über ihre 1H-NMR-Parameter τ (SiH) und J (29SiH) charakterisiert.
Notizen: Über die Lumineszenz von ZnS—Ga-Kristallen
Authors: Szigeti G. , Hársy M. , Schanda J.
Published: February 2015

Es wird gezeigt, daß das Verhalten der Lumineszenz- und Photoleitfähigkeit von ZnS-Kristallen, die aus einer Ga- Schmelze gezüchtet sind, mit dem Modell der Donor-Akzeptor- Paare beschrieben werden kann. Die grüne und rote Emission wird als Rekombination des angeregten bzw. Grundzustandes des Ga-Ions mit einer Zn-Lücke gedeutet. Auch der Einfluß der Stöchiometrie und Temperatur auf die Anregungs- und Emissionsspektren kann mit dem Donor-Akzeptor-Modell erklärt werden.
On a Unified Theory of Twocentre Harmonic Oscillator Integrals I. The Onedimensional Oscillator
Authors: Wltschel W .
Published: February 2015

Twocentre harmonic oscillator overlap integrals, arbitrary transition integrals and collision energy etchange integrals for equal and different frequencies of the oscillators are contained in a generalized Franck-Condon-integral which is solved by operator methods in the second quantization representation.
Mischungswärmen und Verbindungsbildung in binären flüssigen Systemen
Authors: Becker F. , Kiefer M.
Published: February 2015

The enthalpies of mixing at 25° of diethyl ether, di-n-propyl ether, di-n-butyl ether, di-isopropyl ether, propylene oxide, tetrahydrofuran, and tetrahydropyran with chloroform are determined by an isothermal titration method. As a result, the functions HM-f(N CHCl3) are obtained with a step width of 0.025 of the mole fraction and a relative accuracy of 1 per cent or better. Evaluation of the heat of mixing data by means of equilibrium models ("ideal associated mixture") shows that the systems of aliphatic ethers with chloroform behave rather precisely as one-step equilibria of the type A + B = AB (A = ether; B = chloroform). In the systems of cyclic ethers with chloroform, a se­cond equilibrium step, AB + B = AB2 , must be considered, the importance of which decreases with increasing ring size of the ether. The equilibrium data calculated for the seven ether-diloroform systems are discussed.
Main Absorption Region of some Pure Normal Alcohols and of Mixtures of Butyl Alcohol with Non-Polar Solvents
Authors: Hanna F . F . , Hakim I. K .
Published: February 2015

The dielectric constant ε' and dielectric loss ε" are measured for pure n-butyl, n-amyl, n-octyl, n-dodecyl alcohols and for concentrated solutions of n-butyl alcohol in four non-polar solvents at three frequencies between 100 and 400 MHz at three temperatures between 20 and 60 °C. The effective dipole moment has been calculated for the concentrated solutions and the results obtained are discussed. The relaxation times of the concentrated solutions of n-butyl alcohol are in general higher than that of pure n-butyl alcohol (contrary to what was found before in case of n-decyl alcohol) but decreases with increasing dilution.
Thermodiffusion im kritischen Verdampfungsgebiet binärer Systeme
Authors: Haase R. , Borgmann H.-W. , Dücker K.-H. , Lee W.-P.
Published: February 2015

Es werden Messungen des Thermodiffusionsfaktors für das fluide System Methan + Propan beschrieben und diskutiert. Dabei liegt der Druck zwischen 40 und 75 bar, die mittlere Temperatur bei rund 73 °C, der mittlere Molenbruch des Methans zwischen 0,23 und 0,63. Das System befindet sich in der Nähe eines kritischen Verdampfungspunktes, und zwar teils im Gaszustand, teils im hyperkritischen Gebiet. Die Prüfung eines auf Plausibilitätsbetrachtungen beruhenden Ansatzes für den Thermodiffussionsfaktor bei fluiden Zweistoffsystemen (Haase 1950) führt zu einem qualitativ befriedigenden Bild. Insbesondere ist die Aussage, daß der Thermodiffusionsfaktor bei Annäherung an einen kritischen Punkt unendlich wird, mit den Messungen am vorliegenden System und auch an anderen binären fluiden Systemen verträglich.
Innermolekulare Beweglichkeit und dielektrische Relaxation bei drei polaren Molekülgruppen
Authors: Klages G. , Krauss G.
Published: February 2015

lntermolecular Rotation and, Dielectric Relaxation of Three Polar Groups Benzene derivations mono and para-disubstituted by chloromethyl, methoxy and acetyl groups have been investigated. Their complex dielectric constant was measured in dilute mesitylene solutions from -30° to 70 °C and also in benzene and carbon disulfide solutions at 20 °C for frequencies between 0.3 and 135 GHz. Already, chlorobenzene as a rigid molecule shows un-symmetrical absorption curves with flatter slopes at higher frequencies, where the influence of far infrared (FIR) absorption bands becomes noticeable. This additional absorption at millimetre waves can be approximated by a Debye-term. In a first approximation, its time constant is characterized by solvent and temperature and, therefore, has also been taken into account in deriving the relaxation time distribution from the absorption curves of the other molecules. For the discussion it has been assumed that molecules with free rotating groups in para position should have their absorption maximum at higher frequencies than the mono derivatives. Under these conditions relaxation time distributions of molecules with the CH2Cl-group can be derived from the measured absorption curves in such a way that the microwave absorption alone corresponds to the Budo model of a rotating group. The same interpretation may be given for molecules with the OCH3-group. The acetyl group must be considered rigid. Moreover, the paper discusses the activation energies for group rotation, the very high contribution to the FIR-absorption by the orientation polarisation of the investigated groups and the relaxation times of rigid molecules with different orientation of their dipole moment with respect to the long molecular axis
Normal Coordinate Analysis and Mean Amplitudes of Vibration in Acetonitrile-Boron Trifluoride
Authors: Devarajan V. , Cyvin S. J.
Published: February 2015

A complete normal coordinate analysis for the complex acetonitrile-boron trifluoride has been carried out for the first time. Mean amplitudes of vibration, Bastiansen-Morino linear shrinkages, and the most important Coriolis coupling constants have also been determined
Oxygen Isotope Ratios in the Crust of Iron Meteorites
Authors: Heinzinger K. , Iunge C. , Schidlowski M.
Published: February 2015

The separation factor, aM-0= (18O/16O) magnetite/' (18O/16O) atmospheric oxygen, between the magnetite crust of iron meteorites and atmospheric oxygen has been determined to be 0.9946 ± 0.0005. It is concluded that this fractionation of the oxygen isotopes is the consequence of an equilibrium isotope effect at high temperatures. It can be assumed that this is also valid for cosmic spherules, which are mainly ablation products of iron meteorites. As these spherules are found in sediments of different geological ages, their oxygen isotope ratio can give information on the development of atmospheric oxygen.

The difference of the oxygen isotope ratios between magnetite from the lithosphere and airborne magnetite can be used to distinguish between terrestrial and extraterrestrial material.
Relativistic Doppler Effect and Group Velocity in Homogeneous Nonlinear and Inhomogeneous Plasmas
Authors: Nicolis John S. , Athanassoula E.
Published: February 2015

We study the variations of the received frequencies (Complex Doppler effect) from a source moving uniformly in a homogeneous isotropic plasma and emitting a uniform EM plane wave with amplitude E0, as a function of ωe/Eo where ωe is the plasma frequency. The ratio of the velocity U of the source over the group velocity Ugr of the transmitted wave is then calculated from the slope of the Doppler curves.

When the plasma is inhomogeneous (one-dimensional stratification) the Doppler effect depends on the particular profile of the refractive index and its higher (even) derivatives with respect to the direction of stratification z. In this case the ratio U/Ugr=f(z) is given as the solution of a higher order differential equation with inhomogeneous part depending on the slope of the Doppler curve with respect to frequency. Typical cases involving symmetrical and transition profiles are examined. Harmonic generation in the plasma is not taken into account.
Einfluß von Quanteneffekten der Methylgruppenrotation auf die Kernrelaxation in Festkörpern
Authors: Haupt J.
Published: February 2015

By treating the hindered methyl group rotation in solids quantum-mechanically the proton spin lattice relaxation at low temperatures is calculated in first and second order. For low hindering barriers (smaller than 1 kcal/mole) significant differences from the usual relaxation theory are obtained. The inverse correlation time 1/τ0 is essentially given by the rate of non magnetic transitions between the zeroth and first torsional state; and as a consequence the apparent activation energy at low temperatures is given by the difference between these levels. For a given To the relaxation is by a factor ω0/Λ0 (Λ0 is the tunneling frequency) less effective than in the classical case. Good agreement between earlier measurements and this theory is obtained by considering at low efficiency factors also the magnetic interaction between the methylprotons and the surrounding protons. In this way the experimentally observed two relaxation maxima and the ω0-dependence can be explained too.
Mean Amplitudes of Vibration and Coriolis Coupling Constants for Methyl Silyl Acetylene
Authors: Devarajan V.
Published: February 2015

Mean amplitudes of vibration, Bastiansen-Morino linear shrinkages and the most important first order Coriolis coupling constants have been calculated for the molecule Methyl Silyl Acetylene. The effect of torsional vibration on the nonbonded mean amplitudes has also been investigated
Stability to Localized Modes for a Class of Axisymmetric Magnetohydrodynamic Equilibria
Authors: Küppers G. , Tasso H.
Published: February 2015

Mercier’s criterion is computed numerically for an exact class of axisymmetric MHD equilibria having possibly elliptical cross sections and a flat current profile. The main result is that the toroidal current density and the plasma beta can be increased by one order of magnitude if a) the eccentricity of the magnetic surfaces, b) the poloidal current, and c) the aspect ratio are adequately chosen, and if the ellipses are vertical.
Untersuchung der Ion-Molekül-Reaktionen des Thiothionylfluorids mit Hilfe der Ionen-Cyclotronresonanz-Spektrometrie / Investigation Of Ion-Molecule Reactions Of Thiothionylfluorid By Ion Cyclotron Resonance Spectrometry
Authors: Wanczek K.-P. , Lebert K.-H. , Hartmann H.
Published: February 2015

The ion-molecule reactions of thiothionylfluoride have been studied by ion cyclotron resonance spectrometry. The major secondary ions are S2F3
+ , S3F+ , and S3F2
+. In a consecutive reaction of S3F2
+ the tertiary ion S4F2
+ is formed. The rate constant of the IMR with the greatest yield

S2F2
+
+ SSF2 → S3F2
+
+ SF

was estimated to

k = 2 · 10-9 cm 3 molecule -1 sec -1 .

The results were compared with the mass spectrum of thiothionylfluoride. They permit conclusions on chemical reactions of lower sulphurfluorides.
Bildung von van der Waals-Komplexen organischer Moleküle
Authors: Knof Hans , Hausen Volker , Krafft Dieter
Published: February 2015

An electron attachment ion source was modified in order to be used for quantitative measurement of pure organic substances at pressures up to 1.5 ·10-3 Torr in the space around the ion source. The ion intensity was determined by counting the electron pulses produced by single ions in the secondary electron multiplier. This resulted in higher sensitivities. The measurements of different organic compounds showed that molecular polymers are held together primarily by hydro-gen bonding and by dipole interaction. No molecular polymers could be identified in nonpolar substances. The pressure dependence of the ion intensities indicates that the molecular polymers originate from the gas phase of the reservoir. During the ionization process the hydroxide loses its hydrogen atom as was shown with deuterated samples.
Atom-gJ -Faktoren und Lebensdauern der z3 F-Terme im Titan I-Spektrum / Atomic gJ-Values and, Lifetimes of the z 3F-States in the Titanium I-Spectrum
Authors: Hese A.
Published: February 2015

Stimulated by a complete theoretical investigation of the odd configurations in the Titanium Ispectrum the optical double resonance method has been applied to measure the atomic gJ-values and lifetimes of the excited 3d2 4s 4p z 3F2,3,4-states. Using a Titanium atomic beam in natural isotope composition the following values were deduced from the position and the width of the radiofrequency transition signals:

.

The experimental results shall be discussed with respect to other experimental and theoretical values.
Notizen: A Simpler Formula for Certain Integrals in the Theory of the Mössbauer Line Shape
Authors: Cleveland Bruce
Published: February 2015

It is shown that the integrals Qm which occur in the problem of the Mössbauer thick-absorber line shape can be expressed as the real part of a polynomial of degree m.
A Note on the Integral Equation Formulation of Dynamical Theory
Authors: Gjønnes Jon
Published: February 2015

The coupled integral equations for dynamical scattering are developed from the general integral equation. The results are given in the forward scattering approximation. Extension to bade scattering is briefly mentioned. Expressions for distorted crystals are derived both in the column approximation and beyond. The formulation is suggested to be very useful as a basis for perturbation methods.
A Theoretical Analysis of the Weak-beam Method of Electron Microscopy
Authors: Cockayne D.J.H.
Published: February 2015

The geometry of lattice defects can be studied in detail using the weak-beam method 1 of high resolution electron microscopy. In this paper the theoretical basis of the method is discussed, and the experimental conditions which are necessary if particular methods of image interpretation are to be used are considered.
Affine Deformation von linearem Polyäthylen / Affine Deformation of Linear Polyethylene
Authors: Hosemann R , Loboda-Čačković J , Čačković H
Published: February 2015

Linear polyethylene, as an example of high polymers, can have a shape in the molten state and has a "memory" to rebuild the shape it had before having been hot or cold stretched. It is proved that these processes are three dimensional affine deformations of a colloidal superstructure. This superstructure can be characterized as the centres of the crystalline domains in the melt crystallized material, which are interconnected by "non-individual" molecules. It forms the holder of the memory which shows a rubberlike elasticity. The maximum draw ratio up to which the drawing remains a pure affine deformation lies for Lupolen 6001 H (BASF) at approximately 10. The processes within the crystalline domains are very complicated and will not be treated here. It turns out that every single crystalline domain of the melt crystallized material is transformed by stretching into about 20 smaller crystalline domaians which lie together like a string of pearls and form parts of the so-called ultrafibrils of the stretched material. Heated above the melting point, the domains regain their former shape, but with disordered inner structure.

Part of these result were already deal whit during the spring meeting of the Fachausschuß ″Phyisk der Hochpolymeren″ of the German Physical Society, 9-13 March 1971 in Berlin.
Some Characteristics of Dynamical Diffraction at a Bragg Angle of about π/2
Authors: Köhra K , Matsushita T
Published: February 2015

The diffraction phenomena of X-rays in the case ΘB≅π/2 are studied on the basis of dynamical theory. The angular width of diffraction for ΘB= π/2, 2√|χh| , is about 103 times as broad as the one for ΘB ⪡π/2, 2|Xh|/sin ΘB . Similar characteristic phenomena are expected for electrons. The π/2 Bragg angle diffraction would be utilized as X-ray resonator.
Röntgenographi sche Untersuchungen über das Verhalten kondensi erter Materie bei sehr hohen Verdi chtungen und Drucken / X-ray flash investigations on the behaviour of condensed matter at high compressions and pressures
Authors: Schaaffs W , Krehl P
Published: February 2015

An electric spark of high energy density is produced by discharging a capacitor through closely spaced electrodes immersed in a liquid dielectric. A hot plasma arises which is surrounded by a compression ring of highly compressed matter. The shape and state of motion of the compression ring are photographed by the aid of X-ray flashes. Out of the magnitude of the compression, and since the broadening velocity of the compression ring goes nearly to zero, it is concluded that the original liquid in the compression ring undergoes, for a time, a solidification by shock wave pro-cesses. These investigations were carried out in organic liquids and water.
Neubestimmung; der Halbwertszeit des 87Rubidiums durch Vergleich von Messungen an den getrennten Isotopen 87Rb und 85Rb / Redetermination of the half-life of 87rb by comparison of the separated isotopes 85rb and 87rb
Authors: Neumann Walter , Huster E
Published: February 2015

Because of the discrepancies between different determina­tions of the half-life T of 87Rb and the importance of T for measuring geological ages we decided to compare the separat­ed isotopes. All experimental errors are the same in both cases, and the difference of the counting rates has to be attri­buted to 87Rb. In this manner we got T = (4.88 + 0.10) • 1010 y
On the application of OVFF to MX6 type ions
Authors: Rai J. N. , Tiwary S. N. , Rai S. N.
Published: February 2015

Force constants for nine ions belonging to Oh point group have been evaluated by using Orbital Valence Force Field. The constants have been compared with their values obtained by using Urey-Bradley Force Field. The validity of the two methods has been discussed
Influence of Electron and Ion Pressure Near the Lower Hybrid Resonance
Authors: Babu R. , Lammers B. , Schlüter H.
Published: February 2015

Near the lower hybrid resonance the power transfer from electromagnetic waves to a plasma cylinder is calculated with the inclusion of electron and ion pressures. Ion-electron collisions are accounted for in addition to the collisions of charged particles with neutrals. Drastic deviations from calculations neglecting the pressure effects occur for plasmas of low electron density and/or small radial extent. Different ranges of a specific ratio comparing the influence of collision with that of pressure terms are investigated.
Notizen: Low-temperature Heat Capacity and Paramagnetic Susceptibility Measurements on some Tetragonal Nickel(II) Compounds
Authors: Klaaijsen F. W. , Reedijk J .
Published: February 2015

Zero-field splittings have been determined for the spin triplet ground state of Ni(II) in Ni (pyrazole) 4Cl2 and Ni(pyrazole) 4Br2, by means of heat capacity measurements in the 1-80 K region and by paramagnetic susceptibility measurements in the 2-80 K region.

The results of both measurements can be fitted with theory using the spin Hamiltonian

H=gßHS+D[Sz
2-S(S+1)/3]+E(Sx
2-Sy
2)

with the parameter D equal to 7.2 cm-1 for the chloride and 5.4 cm-1 for the bromide. The value of E appeared to be close to zero for both compounds, indicating nearly axial symmetry.

The anisotropic g-values (calculated from the susceptibility) are g⊥ = 2.21 ± 0.03 and g||= 2.14 for the chloride and g⊥ =2.20, g|| =2.12 for the bromide.
Zur Entstehung primärer Gasentladungszonen bei elektrischen Drahtexplosionen / On the Formation of Gas Discharge Zones in Electrical Wire Explosions
Authors: Jäger Helmut
Published: February 2015

Electrical explosions of wires in a conventional condenser discharge circuit have been investigated by correlated electrical and optical diagnostic techniques. Variations of the circuit parameters show details of the explosion phenomena which cause early ignitions of gas discharges at restricted regions of the wire. Under normal conditions these discharges lead to inhomogeneities of the explosion column and prevent further heating of the wire material. A short review about the phenomena is given.
Absorption and Fluorescence Measurements in Compensated Cholesteric Mesophases. Part I: Orientation of Chromophores in Liquid Crystal Solvents
Authors: Mainusch K. -J. , Müller U. , Pollmann P. , Stegemeyer H.
Published: February 2015

A mixture of cholesteric compounds of opposite helical twisting power at a definite temperature Tn gets nematic properties because the long molecular axes take a parallel arrangement. If the sample is placed between lecithin-treated quartz plates the long axes at Tn switch by an angle of 90° into a direction normal to the cover surfaces. As the orientation of the cholesteric molecules is transferred to the anisotropic solute molecules this effect has been detected by means of measure­ment of absorptivity and fluorescence efficiency of soluted chromophores. By the method described a possibility opens to determine the direction of optical transitions by a very simple technique.
Zur Struktur der Schuster-Bande / On the Structure of the Schuster Band
Authors: Weisbeck Roland
Published: February 2015

The emission spectrum of a low pressure microwave discharge in ammonia reveals the Schuster band between 5600 and 5700 Å superposed by many intense lines, about one half of which belong to the α-band of the NH2 radical. The other lines have not been identified; presumably, they may be ascribed to a polyatomic molecule consisting of N and H atoms.
The Molecular Zeeman Effect in Selenophene
Authors: Czieslik W. , Sutter D. , Dreizler H. , Norris C. L. , Rock S. L. , Flygare W. H.
Published: February 2015

The molecular Zeeman effect in the rotational spectrum of selenophene has been observed. The molecular g-values and the magnetic susceptibility anisotropics for selenophene 80Se are: gaa = -0.0849±0.0012, gbb= -0.0428±0.0011, gcc = + 0.365 ±0.0010, 2 Xaa-Xcc=50.15±0.80, 2 Xbb-Xcc-Zaa = 51.83 ± 1.3. From the comparison of the value ⊿X=2 Xcc-Xaa-Xbb in furan, thiophene and selenophene we conclude that the aromaticities of these molecules would be in the order: furan < thiophene ≌ selenophene.
Concentration Quenching and Depolarisation of Photoluminescence in Solutions
Authors: Bojarski C , Dudkiewicz J
Published: February 2015

The emission anisotropy r/r0 and quantum yield η/η0 of the photoluminescence of glycerin-water solutions of Na-fluorescein has been measured at concentrations 10-6 - 3·10-1 M. The drop of η/η0 is connected with a repolarisation effect, which is interpreted by a completed theory of con-centrational depolarisation of photoluminescence (CDPL), accounting the self-quenching by non-luminescent dimers and the remigration of excitation energy. The dimerisation constant and the critical concentrations have been determined.
Molar Volumes in Molten KCl, RbCl, TlCl, KCl-TlCl, and RbCl-TlCl
Authors: Buckle E.R. , Tsaoussoglou P.E.
Published: February 2015

Densities in molten KCl, RbCl, TlCl, KCl-TlCl and RbCl-TlCl at various temperatures (t °C) were measured to within ±0.1% by iridium pyknometry. For the pure melts the results fit empirical equations of the form ρ=a-bt. The molar volumes at the melting points were derived and tested against other melting-point data for thermodynamic consistency. In the mixtures the volumes deviate from additivity in both directions, and it is again evident that the sign and magnitude of the deviation at a given composition are sensitive to temperature. In the present systems the negative deviations are much less persistent at high temperatures than in KBr -TIBr.
Relaxation of Diffused Zinc Atoms During Short-Range-Ordering in Cu-30% Zn Alloy
Authors: Youssef T. H.
Published: February 2015

The internal friction which is a diffusion dependent physical property has been used as a means to determine the kinetics of short range order in (Cu-30% Zn) alloy. Curves of relative (Q~ l /Q0~ 1) against annealing time have been plotted for various annealing temperatures. An average activation energy of 1.7 eV was found for the ordering process, which is equal to the activation energy for zinc diffusion in coarse grained copper. When an alloy having short range order (SRO), is quenched from high temperatures, excess vacan-cies are liberated which will enhance diffusion, and hence the ordering rate during subsequent anneal-ing. Due to this enhanced ordering rate, the equi-librium degree of short range order canbe achieved in reasonable times even at rather low temperatures, provided that vacancies are mobile at these tempera-tures. For copper-zinc alloys in the alpha phase, the existence of SRO has been theoretically 1 establish-ed and experimentally demonstrated by many wor-kers (cf. CLAREBROUGH et al. 2). Evidence from diffuse X-ray and/or neutron scattering experiments is not available because of the small difference in scattering power of copper and zinc 3 atoms. Long range order in alpha brass above — 30 °C is im-probable 3 because of the rather low ordering en-ergy of the system.