bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Interpretation of Absorption Spectra of Technetium (IV) and Rhenium (IV) Hexahalides
Authors: Jørgensen Chr. Klixbüll , Schwochau Klaus
Published: March 2015

Absorption spectra of aqueous solutions of TcX6
- and ReX6
- (X = F, Cl, Br, I) are measured between 8 000 and ∼ 50 000 cm-1 and theoretically discussed. The electron transfer spectra indicate the optical electronegativity xopt= 2.25 for Tc (IV) and 2.05 for the less oxidizing Re (IV). The spectrochemical parameter Δ is determined to 28 400 cm-1 in TcF6 and 32 800 cm-1 in ReF6
-. The nephelauxetic effect is evaluated from the spin-forbidden intra-sub-shell transitions in all eight species, and from the two spin-allowed bands of TcF6
- The vibrational structure of the narrow absorption bands and the possible weak distortion from octahedral symmetry of Tc (IV) hexahalides are discussed.
The Electrical Conductivity of Molten Lithium Molybdate
Authors: Kvist Arnold , Lundén Arnold
Published: March 2015

The electrical conductivity of Li2MoO4 has been measured on both sides of the melting point in order to see whether this salt has a high temperature modification with properties similar to α-Li2SO4. This was found not to be the case. The temperature dependence of the conductivity was studied for the melt, giving

κ= —2.518 + 6.999·10-3 t-1.356·10-6 t2 Ω-1Q-1 cm-1 (704-950°C).

There is a discrepancy between our results and recent measurements by MORRIS and ROBINSON. Possible explanations are discussed.
Feldionen-Massenspektren organischer Moleküle. II. Amine
Authors: Beckey H. D. , Wagner G.
Published: March 2015

The field ion mass spectra of unbranched and branched amines with carbon numbers from C2 to C10 are discussed. Both thin platinum wires and tips have been used for production of the ionizing high fields. Some general rules are derived from the mass spectra which are consistent with the theoretical model used for interpretation of field ion mass spectra. The results lead to an extension of the model to polar molecules, regarding the influence of orientation of the molecules on the field ion mass spectra.
Interference and Radial Distribution Functions of Liquid Copper, Silver, Tin, and Mercury
Authors: Wagner C. N. J. , Ocken H. , Joshi M. L.
Published: March 2015

The x-ray scattering from liquid copper, silver, tin, and mercury was measured at temperatures of 1125°C, 1050°C, 335°C, and 28°C, respectively, from the open surface of horizontal samples using a focusing theta-theta diffractometer, quartz crystal monochromator positioned in the diffracted beam, scintillation detector, and pulse height discriminator. The effect on the measured intensities of the positioning of the sample with respect to the diffractometer axis and the meniscus of the liquid were considered. Calibration of the primary beam intensity by measurements on liquid mercury provided an alternate check of the standard normalization procedures for copper, silver, and tin. After calculation of the interference functions, atomic and radial distribution functions were evaluated from which interatomic distances and coordination numbers were obtained. The interatomic distances in the liquid were in good agreement with the GOLDSCHMIDT diameters of the respective elements.
Dynamical Theory of Electron Diffraction for Finite Crystals
Authors: Fujimoto Fuminori
Published: March 2015

The dynamical theory of electron diffraction for a finite crystal is developed by using higher BORN approximations. The general formula obtained here is applied to wedge-shaped and spherical crystals. In the latter case, the intensity, integrated intensity and line breadth of the DEBYE-SCHERRER ring are calculated. The results indicate an anomaly of line breadth.
Verstärkung der Fluoreszenz von Chelaten der Seltenen Erden durch zusätzliche Koordination
Authors: Butter E. , Kreher K.
Published: March 2015

It is shown that the fluorescence of various Eu-chelates (dibenzoylmethide, benzoylacetonate, acetylacetonate and β-naphthoylacetonate) is much enhanced by additional coordination of ophenanthroline or α.α'-dipyridil. Complexes of the composition Eu (β-diketone)3-Phen, Eu(β- diketone)3-Dip etc. could be isolated and the absorption and the fluorescence in various solvents was studied. Compared to the trischelates the temperature dependence of the additional coordinated chelates is remarkably reduced.
Notizen: A Redetermination of the Isotopic Composition of Atmospheric Neon
Authors: Eberhardt P. , Eugster O. , Marti K.
Published: March 2015

A redetermination of the isotopic composition of atmospheric neon gave abundance ratios 20Ne/22Ne = 9.80 ± 0.08 and 20Ne/21Ne = 338.0 ± 2 .5 , corresponding to percentage abundances of 90.50 ± 0.07 , 0.268 ±0.002 and 9.23 ±0.07 for 20Ne, 21Ne and 22Ne, respectively. These abundances correspond to an atomic weight of 20.179 ± 0.002 for atmospheric neon.
Messung der Absorptionsoszillatorenstärken von NI-Multipletts am Kaskadenlichtbogen im Wellenlängenbereich zwischen 1000 und 1800 Å
Authors: Labuhn Franz
Published: March 2015

The absorption oscillator strengths of 35 NI-multiplets between 1000 and 1800 A are measured in emission. The light source is a wall-stabilized cascade arc burning in definite argon-nitrogen mixtures. Normal-intensities are produced by the same source. The evaluation of particle densities is carried out without assuming constancy of mixture ratio and knowledge of any transition probability.
Untersuchung von einfachen π-Elektronensystemen mit Hilfe von Elektronenspin-Resonanz und Polarographie
Authors: Möbius K.
Published: March 2015

It was the intention of this study to test the molecular orbital approximations of HÜCKEL and McLACHLAN by means of the experimental methods of EPR and polarography. In the experimental part problems are discussed as to electrolytic generation of free radicals and as to the ERP method with g-factors being measured with an accuracy of ± 2 ppm. In the theoretical part the molecular orbital theories of HÜCKEL and MCLACHLAN are summerized with particular regard to quantities which can be measured by EPR and polarography. A simple model of a σ → π → σ* excitation is developed which predicts a linear correlation between g-factor shift and π-energy of the lowest half-filled orbital. The validity of the model is discussed in terms of the g-factor theory recently deduced by STONE. The results of the experiments are presented in a subsequent paper.
Der Verstärkungsfaktor der Photoleitung bei diskretem Haftstellenniveau und nachlieferndem Kontakt
Authors: Harth W. , Dommaschk W.
Published: March 2015

Für Photoleiter mit tiefliegenden Rekombinationszentren, einem einzelnen Haftstellenniveau und nachlieferndem Kontakt wird der Verstärkungsfaktor unter Vernachlässigung der Löcherleitung untersucht. Die Spannungscharakteristik des Verstärkungsfaktors und ihre Abhängigkeit von den verschiedenen Parametern, insbesondere von der Lage des Haftstellenniveaus, werden numerisch ermittelt. Für das in der Spannungscharakteristik meist auftretende scharfe Maximum wird ein Ausdruck angegeben, der zwei bereits bekannte Grenzfälle einschließt. Es zeigt sich, daß der maximale Verstärkungsfaktor besonders bei hoher Haftstellenkonzentration, tiefer Temperatur und geringer Einstrahlung den Sättigungswert um mehrere Größenordnungen überschreiten kann. Seinen größten Wert erreicht er jeweils dann, wenn das Haftstellenniveau in der Nähe des FERMI-Niveaus liegt.
Feldionen-Massenspektren organischer Moleküle IV. Olefine
Authors: Beckey H. D. , Schulze P.
Published: March 2015

The field ion mass spectra of the olefins are discussed. It is shown that the double bond and the bond next to it are very stable against field dissociation. The fragment patterns of all olefins show some features due to the stable configuration of the allyl radical or the allyl ion respectively. This is verified by some energetic calculations, by which the spectra of some olefins are explained, too. The stabilities of paraffins and olefins against field dissociation are compared.
Hochaufgelöste Protonenresonanzspektren mit direkter magnetischer Dipol-Dipol-Wechselwirkung, Teil III
Authors: Englert G. , Saupe A.
Published: March 2015

The analysis of the proton magnetic resonance spectra of a 3-protonsystem with C2-symmetry and of a special 4-protonsystem (rotating methylgroup and one interacting proton) is given in terms of the magnetic dipole-dipole couplings and the chemical shifts. The application to the spectrum of 3,5-dichloro-benzoic acid, dissolved in nematic 6-n-hexyloxy-2-naphthoic acid, and to 2,3,5,6- and 2,3,4,6-tetrachloro-anisole and 2,3,5,6-tetrachloro-toluene, dissolved in nematic 4,4-di-n-hexyloxy- or -heptyloxy-azoxybenzene gives information on the molecular orientation and the anisotropy of the chemical shifts. The ratio of the proton-proton distances of the toluene compound is determined.
Nachweis metastabiler Ionen mit langen Lebensdauern
Authors: Tatarczyk H. , Zahn U. von
Published: March 2015

In order to search for metastable ions with long lifetimes hydrocarbon molecules are ionized by electron impact and the fragment ions preselected by a magnetic spectrometer. Subsequently these selected ions M0
+ pass a drift tube where they may decay into ions M1
+, Μ2
+, .... Behind the drift tube a quadrupole spectrometer is used to analyze the ion current for its mass components M0
+, M1
+

For selected species of fragment ions M0
+ of n-butane, n-pentane, and n-hexane it was found that between 10% and 20% of M0+ decay in the time interval of 10 μs to 150 μs after ionization. Furthermore, 150 μs after ionization (0.040 ± 0.025) % of mass 86+ ions from n-hexane decompose into 56+ fragment ions per 1 μs.
Electromigration Mobilities of Cadmium in Molten Cadmium Bromide, Pure and with Dissolved Cadmium Metal
Authors: Holmlid Inge
Published: March 2015

The mass effect of the cadmium ions for electromigration in pure molten cadmium bromide has been determined to —0.075 ± 0.004. An electromigration experiment with a solution of cadmium metal in molten cadmium bromide is discussed. It is concluded that the dissolved metal has a smaller mobility than the cadmium ions.
Kraftkonstantenberechnung nach einer Methode der nächsten Lösung
Authors: Fadini A.
Published: March 2015

Die Berechnung von Molekülkraftkonstanten aus der Säkulargleichung | G•F—λΕ|= 0 führt im allgemeinen auf eine unendliche reelle Lösungsmannigfaltigkeit F, wenn nur die inverse Matrix G der kinetischen Energie und die Spektralmatrix L=Diag(λi) mit i=1, 2,..., n bekannt sind. Bei einer Reihe von Molekülen können Näherungslösungen Fnäh bestimmt werden, und wir geben ein Verfahren an, durch das aus F eine Matrix Fmin als Kraftkonstantenmatrix ausgewählt wird, die der Näherungslösung Fnäh am nächsten liegt. Für dieses sogen, erweiterte inverse Eigenwertproblem der Ordnung n=2 wird die Bedingung für die Existenz eines reellen Lösungsbereiches angegeben, die Lösungsmethode als Näherungsverfahren explizit dargestellt und das mathematische Modell der nächsten Lösung geometrisch interpretiert. An den beiden Molekülen BrCN und OCS wird das Verfahren erprobt. Im Falle gleicher Eigenwerte existiert für n=2 nur die eine reelle Lösung F (λ)=λ•G-1.
Untersuchung von Strahlungsdefekten in GaP mittels Elektronenresonanz
Authors: Kimmel H.
Published: March 2015

Aus der Hyperfeinstruktur der Elektronenresonanz-Spektren von Elektronen- und Protonenbestrahltem GaP ergibt sich, daß Defekte auftreten, in denen ungepaarte Elektronen in Wechselwirkung entweder mit zwei Ga-Atomen oder mit zwei P-Atomen stehen. Bei den beobachteten Defekten dürfte es sich um die dem Si—Α-Zentrum entsprechenden Defekte dieser im Zinkblende-Gitter kristallisierenden binären Verbindung handeln.
Das Eutektikum InSb—Mg3Sb2
Authors: Müller A. , Wilhelm M.
Published: March 2015

InSb und Mg3Sb2 bilden ein lamellares Eutektikum. Die eutektisdie Konzentration liegt bei 2,2 Gew.-Proz. Mg3Sb2.

Die Mg3Sb2-Lamellen verwachsen im eutektischen Gefüge mit {111}-Flächen von InSb. Es besteht Grund zur Annahme, daß die Verwachsungsflächen der Mg3Sb2-Lamellen (0001)-Ebenen im Gitter von α-Mg3Sb2 sind.

Die Abhängigkeit des Lamellenabstandes von der Kristallisationsgeschwindigkeit wurde untersucht.
Instabilitäten, Turbulenz und Funkelrauschen in Halbleitern II Vom eigenen Magnetfeld bewirkte Strominstabilitäten
Authors: Handel P. H.
Published: March 2015

Es wird gezeigt, daß in Gegenwart einer quer zur Stromrichtung verlaufenden Potentialschwelle im Halbleiter das eigene Magnetfeld des Stromes I Instabilitäten im Plasma der Ladungsträger hervorruft. Diese sind mit den Pinch-Instabilitäten verwandt. Während bei letzteren die instabilen Glieder quadratisch von I abhängen, tritt hier wegen dem starken elektrischen Feld der Potentialschwelle eine lineare I-Abhängigkeit der instabilen Glieder auf. Dadurch ergibt sich eine viel kleinere kritische Stromstärke als bei dem Pinch-Effekt. Diese bei Kontakten, Korngrenzen u. a. Halbleiterinhomogenitäten, sowie allgemein bei Potentialschwellen auftretenden Instabitiläten sind am ehesten geeignet, schon bei kleinen Belastungen hydromagnetische Turbulenz im zweikomponentigen Ladungsträgerplasma auszulösen.
The Variation of the Adiabatic Invariant of the Harmonic Oscillator
Authors: Knorr G. , Pfirsch D.
Published: March 2015

The variation of the adiabatic invariant μ of a harmonic oscillator or gyrating particle in a time varying homogeneous magnetic field is given as an absolutely converging series. This solution is used to discuss the behaviour of the adiabatic invariant for slow and fast as well as small and large variations of the oscillator strength.

General estimates are obtained for the dependence of the oscillator strength which is twice differentiable or which is analytic. For the latter case it is found that Δμ tends to zero at least as exp [ — (2 d — ε)/α] for α → 0; 2 d is the width of the analytic strip of ω (α t); α characterizes the slowness of the variation and ε is any number 2 d > ε > 0.
Theorie der stoßfreien Plasmasäule unter Berücksichtigung des Wandverlustes
Authors: Ecker G. , Kanne H.
Published: March 2015

The collision-free plasma column has been investigated without a magnetic field in the normal and subnormal region neglecting wall losses. This neglection simplifies the analysis appreciably since it allows to describe the electrons by a BOLTZMANN distribution. However, in the subnormal region and in strong magnetic fields the wall loss is a decisive factor. Therefore our investigation extends the theory including this effect.

Starting from the transport equations particle density and potential distributions as well as the current-voltage characteristic are found by numerical integration.

With increasing magnetic field the particle density profiles grow wider whereas the potential distribution grows flatter. These effects are particularly pronounced in the subnormal region. In this region the I/V-characteristic shows a negative slope, which for a given current decreases with increasing magnetic field.
Das dielektrische Verhalten der Ferroelektrika bei einer Umwandlung zweiter Ordnung
Authors: Müser Horst E. , Unruh Hans-Günther
Published: March 2015

For ferroelectric crystals with a second order transition the phenomenological theory predicts an infinite value of the dielectric constant at the CURIE-point. The highest value observed in the case of Rochelle salt is only about 104. This is not caused by the methods of sample preparation or measurement but by a dispersion of the permittivity. The temperature dependence of the dielectric constant and of the dielectric modulus (dielectric impermeability) at constant frequency is examined. The influence of several relaxation mechanisms on the formation of the spontaneous polarization is discussed.
Abgeschirmte piezoelektrische Potentiale um Versetzungen in piezoelektrischen Kristallen
Authors: Merten Ludwig
Published: March 2015

Die Abschirmung von piezoelektrischen Potentialen um Versetzungen in piezoelektrischen Halbleitern läßt sich sehr allgemein behandeln. Bei Darstellung dieser abgeschirmten Potentiale als FouRIER-Reihen in φ, die nur geradzahlige Harmonische enthalten, sind die r-abhängigen FOURIER-Koeffizienten des Index 2n Summen aus der modifizierten HANKELschen Funktion und der sogen. LOMMELschen Funktion 2n-ter Ordnung. (τ, φ: Polarkoordinaten in den Ebenen ⊥ zur Versetzungslinie.)
Die Reaktionen 30Si(d, p)31Si und 30Si(3He, d)31P
Authors: Betigeri M. , Bock R. , Duhm H. H. , Martin S. , Stock R.
Published: March 2015

Es wurden die Reaktionen 30Si(d, p)31Si bei Ed = 10 MeV und 30Si(3He, d)31P bei E3He = 15 MeV mit einem Breitbandmagnetspektrographen untersucht. Für 31Si wurden Winkelverteilungen für 20 Niveaus von 5° bis 120° gemessen und mit einer DWBA Analyse wurden l-Werte und spektroskopische Faktoren bestimmt. Auf Grund der Targetzusammensetzung wurden zugleich mit dem 31Si 23 Niveaus im 29Si gemessen, deren spektroskopische Faktoren mit früheren Messungen 1 übereinstimmen. Die l = 2 Winkelverteilungen sind strukturiert oder flach je nach dem dem Spin 3/2+ oder 5/2+ des Endzustandes, so daß sich durch Vergleich auch die Spins der Niveaus im 31Si bestimmen ließen. Im 31P wurden die l-Werte und relativen spektroskopischen Faktoren aus 4 Spektren bei 4 ausgewählten Winkeln bestimmt. Eine Interpretation der Niveaustruktur und der spektroskopischen Faktoren von 31Si und 31P nach den Schalenmodellrechnungen von GLAUDEMANS et al. 2 schlägt fehl, vor allem da in den Rechnungen die d5/2 Schale als abgeschlossen betrachtet wird. Die versuchsweise Anwendung des NILssoN-Models führt auf kleine Deformationen | η | < 2, ohne die Niveauleiter indessen exakt erklären zu können.
Über die Formierung der Oberflächensperrschicht von Siliciumdetektoren
Authors: Bader R. , Kalbitzer S.
Published: March 2015

Es wurde der Formierungsvorgang von Oberflächensperrschichten auf goldbedampftem n-Silicium untersucht, wobei Goldschichtdicke, Temperatur und Sauerstoffdruck variiert wurden. Gemessen wurde in allen Fällen die Verzögerungszeit, die zwischen dem Zeitpunkt der Sauerstoffzufuhr und der Ausbildung der Sperrschicht liegt. Die Aktivierungsenergie der Sauerstoffdiffusion beträgt 0,85 ± 0,04 eV. Die Verzögerungszeit ist quadratisch von der Goldschichtdicke abhängig und zeigt weiterhin eine Druckabhängigkeit.
Molecular Motion in Liquids and Solutions. II.
Authors: Krüger G. J. , Müller-Warmuth W. , Van Steenwinkel R.
Published: March 2015

Two methods are utilized to study the relaxation behaviour and molecular motion in solutions of free radicals in toluene: the investigation of longitudinal and transversal solvent proton relaxation at a properly chosen frequency (48 MHz), and the determination of enhancement factors of the dynamic proton polarization over a large frequency range. The temperature dependence of the quantities concerned is measured between +70°C and —120°C.

The results can be interpreted in terms of a pure dipole-dipole interaction between proton and electron spins whose time dependence is provided by translational random motions of the molecules and rotational tumbling of associated complexes. The activation energies for both processes are 3.1 kcal/mole and 7.8 kcal/mole, respectively. The solvation is only very weak. The relative contribution of rotational tumbling is R=0.26, from which the average co-ordination number is estimated to be less than one.
K-Ar-Altersbestimmungen an Ultrabasiten des Baltischen Schildes
Authors: Kirsten T. , Gentner W.
Published: March 2015

The K-Ar-ages of five ultrabasic rocks from the Baltic Shield were determined. K-Ar-ages of 3.7 to 8.8 x 109 y were obtained. Two samples were cut into fractions with different potassium content and a partial correlation of the argon content with the potassium content in the separated fractions was noticed. The question of extraneous argon causing higher age values is discussed. Taking into consideration the previous results obtained by GERLING et al., it may be said, that extremely high Ar40/K-ratios are the rule for ultrabasic rocks from the Baltic Shield. As a consequence of this fact, it is not likely that all these rocks have the age only of the precambrian pluton in which they are incorporated. Assuming that the alpinotype peridotites were transported upwards in the form of solid fractions from the upper mantle, it is possible, that actually radiogenic argon exists more or less in the sample.

The highest Ar40/K-ratios (according to ages ranging from 5.9 to 10.9 x 109 y) exhibit the samples with potassium contents below 100 ppm. Samples with potassium contents more than 1‰ have much smaller Ar40/K-ratios (according to ages from 4.2 to 5 x 109 y) . Excess argon probably causes the extremely high “ages” of more than 7 x 109 y. The ages from relative potassium-rich samples will eventuible show the true age. The most likely value for this age is 4.2 x 109 y, measured for a peridotite with 0.49% potassium content.
Die Lösungsmittelabhängigkeit der Intensität von Elektronenbanden. I. Theorie
Authors: Liptay W.
Published: March 2015

Die Lösungsmittelabhängigkeit der Intensität von Elektronenbanden wird auf eine Lösungsmittelabhängigkeit der Übergangsmomente zurückgeführt. Eine Störungsrechnung zweiter Ordnung in Dipol-Dipol-Approximation zeigt, daß die Lösungsmittelabhängigkeit des Übergangsmoments wesentlich durch die Beeinflussung des Übergangsmoments durch ein äußeres elektrisches Feld gedeutet werden kann. Für gelöste Moleküle, die ein permanentes elektrisches Dipolmoment besitzen, wirkt das durch das Dipolmoment induzierte Reaktionsfeld wie ein äußeres elektrisches Feld. Der Betrag des effektiven Reaktionsfeldes hängt von der Dielektrizitätskonstante und dem Brechungsindex des Lösungsmittels ab, wodurch schließlich der Hauptanteil der Lösungmittelabhängigkeit der Intensität von Elektronenbanden verursacht wird. Einen im allgemeinen kleinen Beitrag liefert ein weiteres Glied, das durch Dispersionswechselwirkungen erklärt werden kann und das bei der meist geringen Lösungsmittelabhängigkeit von dipollosen Molekülen oder von Molekülen mit einem kleinen Dipolmoment eine Rolle spielen kann. Größere Lösungsmittelabhängigkeiten der Intensität sind nur bei Molekülen mit größeren Dipolmomenten zu erwarten. Die Ursachen sind von ähnlicher Natur wie die Ursachen der Bandenverschiebung in Abhängigkeit vom Lösungsmittel 1.
Schwingungsspektren von Derivaten des Pentaerythrits
Authors: Geiseler G. , Ratz L.
Published: March 2015

Infrared absorption spectra (4000—400 cm-1) and RAMAN spectra of the pentaerythritol halides have been examined. By comparison with spectra of similar compounds and by a normal coordinate analysis with the aid of the GF-Matrix-Method of WILSON and on the basis of a modified valence force field it was possible to assign a great deal of the normal vibrations. The influence of the halogen atoms on the frequency of characteristic vibrations has been discussed.
Untersuchungen der IR-Gruppenintensitäten einiger monosubstituierter Pyridin- und Benzolderivate
Authors: Joeckle R. , Schmid E. D. , Mecke R.
Published: March 2015

Der Einfluß des Hetero-N-Atoms auf die Elektronendichteverteilung in Pyridin wurde bei einer Reihe von monosubstituierten Pyridin- und Benzolderivaten mit Hilfe vergleichender Messungen von Gruppenintensitäten IGr der im Substituenten lokalisierten Valenzschwingungen untersucht (Gr = CH3, CH2, CN und NH2). Neben einem Reichweiteeffekt ist ein stark alternierender Effekt auf IGr zu beobachten. Durch Einbau einer CH2-Gruppe zwischen Ring und funktioneller Gruppe (Φ —CH2—Gr) wird die Wirkung beider Effekte abgeschwächt. Verglichen mit der entsprechenden Benzolverbindung nimmt IGr monosubstituierter Pyridinderivate bei den Gruppen — CH3, — CH2 und — CN ab, bei — NH2 hingegen zu. Dieser Sachverhalt läßt sich u. E. folgendermaßen interpretieren: Das Hetero-N-Atom induziert auf Grund seiner Elektronenakzeptorwirkung in den Bindungsorbitalen Momente der Richtung A-—B+ (A sei das ringnahe Atom). Bei Gruppen der Polarität A-—B+ führt dies zu einer Erhöhung, bei Gruppen der Polarität A+—B- zu einer Verkleinerung des resultierenden Bindungsdipolmoments. Obwohl im allgemeinen kein einfacher Zusammenhang zwischen IGr und den Ableitungen der Bindungsdipolmomente (მμ/მR)j, Gr und den Bindungsdipolmomenten μj, Gr selbst besteht, gilt möglicherweise allgemein: Die Gruppenintensität nimmt als Folge der Akzeptorwirkung eines Heteroatoms ab, wenn die Polarität der in der Gruppe enthaltenen Bindungen A+—B- ist. Bei umgekehrter Polarität nimmt andererseits IGr zu. Die Größe der Änderungen hängt von der Art der Gruppe ab. Mit Hilfe der erhaltenen Gruppenintensitäten war es ferner möglich, dem Hetero-N-Atom des Pyridins folgende Substituentenparameter (ΗΑΜΜΕΤT-Konstanten) zuzuordnen:

σN, ortho = 0,68 ± 0,10; σN, meta = 0,33 ± 0,10; σN, para = 0,66 ± 0,10 .
Paramagnetische Elektronenresonanz thermisch und durch Strahlung erzeugter Zentren in Bornitrid
Authors: Römelt G.
Published: March 2015

By X-rays, ultraviolet, and γ-radiation or by heating to more than 1850 °C in powdered or sintered boronnitride centres are produced, which give an EPR-spectrum with 10 lines a=7.8 ± 0.1 Gauss apart with g=2.0027 ± 0.0003 for BN of natural isotopic composition (81.17% 11B; 18.83% 10B), and a single line for 10BN enriched to 91% 10B. The spectra are analysed as built up from 4 systems of spectra, caused by surroundings of 3 boron atoms, 3, 2, 1, or 0 of which are 11B, each occuring with the proper probability. The intensity of the different systems was calculated by assuming GAussian line shape and equal | ψ (0) |2 and line width for 11B and 10B. It is possible, that the EPR is caused by impurity atoms on the places of N or in the centre of B3N3-rings. Other spectra caused in BN by X-rays or by neutrons in a pile are discussed elsewhere 3, 8.
Zur Bestimmung des Fano-Faktors von Ge(Li)-Detektoren
Authors: Ruge Ingolf , Eichinger Peter
Published: March 2015

Within the last two years the FANO factor F for Ge (Li)-detectors, which defines the theoretical limit for the resolution in the area of spectroscopy in regard to the detector, was found out experimentally several times. The values obtained for F vary between 0.7 and 0.15. In order to find out the reasons for these variations the dependence of the energy resolution on the electric field was examined at various gamma-energies for several Ge (Li)-detectors. Even at very high electric fields (several kilovolts/cm) still a field dependence especially at high gamma-energies appeared, which could be explained in terms of charge collection time. As condition for an exact determination of the FANO factor the extrapolation of the resolution to field strength infinity is set up; with this method the value of the FANO factor for Ge (Li)-detectors, used here, was estimated to 0.20 ±0.05.
EPR-Untersuchungen an kupferdotierten Triglyzinsulfat- und Glyzin-Einkristallen
Authors: Windsch W. , Welter M.
Published: March 2015

Der Einbau von Kupferionen in Triglyzinsulfat- und Glyzin-Einkristalle wird untersucht. Die Dotierung der Kristalle erfolgt beim Züchten durch Einbau von Kupfer (II) -Glyzinat-Komplexen aus der Mutterlösung. Es werden die Molekularbahnen für die Symmetrie D2h konstruiert. Aus den experimentell bestimmten Parametern des Spin-Hamilton-Operators werden die Bindungsparameter des orthorhombischen Komplexes berechnet und diskutiert. Der Einfluß der Kupferdotierung auf die ferroelektrischen Eigenschaften von Triglyzinsulfat wird diskutiert.
The Internal Conversion Electron Spectrum of 147Nd
Authors: Bashandy E. , El-Haliem A. Abd
Published: March 2015

The internal conversion electron spectrum following the β-decay of 147Nd has been studied using, an iron yoke and an iron free double focussing β-ray spectrometer at a momentum resolution of about 0.2%. A total of 66 transitions has been ascribed to this decay. On the basis of statistical analysis of sum relationships for the transition energies, combined with earlier reported coincidence results, a decay scheme involving 16 excited levels is suggested. The experimental data indicate a higher state at 763 keV. Its energy is close to the high state observed in other promethium nuclei.

The multipolarity assignment for each transition was obtained by comparing the observed conversion line intensity ratios with the theoretical line intensity ratios of SLIV and BAND. From the multipolarity values obtained, the spins and parities of the excited levels in 147Pm are assigned and discussed in terms of recent nuclear models.
Zum Hinderungspotential der internen Rotation der Methylgruppen in Dimethyldisulfid
Authors: Sutter D. , Dreizler H. , Rudolph H. D.
Published: March 2015

The barrier to the internal rotation of the two methyl-tops has been calculated from quartet splittings of six rotational transitions with J values up to five. Using the data of the r0-structure, one obtains s= (4 V3)/ (9 F) = 43.4. If s and the direction cosine λα are fitted simultaneously to the multiplet splittings, which leads to an angle of about 2° between the S—C-bond and the axis of internal rotation, one obtains s=43.78. A brief sketch of the method used to diagonalize the complex HAMILTONian matrix is given.
Zur Aktivität von Methyltorsionsschwingungen in Zweikreiselmolekülen
Authors: Dreizler H.
Published: March 2015

Für Moleküle mit zwei äquivalenten Methylgruppen wird ein Vorschlag formuliert, die Aktivität der Methyltorsionsschwingungen durch eine Wechselwirkung zwischen den Torsionsschwingungen und der Rotation zu verstehen. Die Wechselwirkung zwischen den beiden Methyltorsionsschwingungen ist für diese Betrachtung nicht wesentlich.
The Electrical Conductivity and Density of Solid and Molten Li2SO4 — Ag2SO4
Authors: Kvist Arnold
Published: March 2015

The electrical conductivity of solid and molten Li2SO4—Ag2SO4 has been measured for different concentration values. Density measurements of molten Li2SO4, Ag2SO4 and equimolar (Li, Ag) 2SO4 show that the system can be considered ideal. The equivalent conductivity of molten (Li, Ag)2SO4 can be calculated from the conductivities of the pure salts by assuming that the cations are moving in groups, each group containing about four cations.
Gefügeformen im Eutektikum InSb — NiSb
Authors: Müller A. , Wilhelm M.
Published: March 2015

Im anomalen Eutektikum InSb —NiSb können drei Arten des Matrixgefüges unterschieden werden: polykristallin, monokristallin, faserig. Gewinnung von Eutektikum der drei Gefügearten, sowie deren Einfluß auf die Ausrichtung des nadeligen, eingeschlossenen Gefügebestandteils NiSb werden beschrieben. Der Quotient aus Besetzungsdichte der Nadeln und Kristallisationsgeschwindigkeit ist konstant und gleich 8,2 × 104 min/mm3.
K-Conversion Coefficients of Transitions in In114 and Cd114
Authors: El-Nesr M. S. , Awwad Z. , El-Aassar M. R.
Published: March 2015

The K-conversion coefficients of the 192 keV isomeric transition in In114 and the 556 and 722 keV transitions in Cd114 have been measured for the first time by means of a high resolution double focusing β-ray spectrometer, using the internal-external conversion method. The results obtained are:

αk (192 keV-In114) = 2.3653 ± 0.3075,

in excellent agreement with the theoretical value 2.4638 for pure E4 transition calculated by SLIV and BAND, and

αK (556 keV-Cd114) = 0.00419 ± 0.00046,

αK (722 keV - Cd114) = 0.00207 ± 0.00025,

both results in excellent agreement with the theoretical values for pure electric quadrupole radiation 0.00432 and 0.00218 respectively computed by SLIV and BAND. These data confirm the essentially pure E4 character of the 5 + → 1 +, 192 keV transition in In114 and the pure E2 character of the 4 + → 2 +, 722 keV and 2 + → 0 +, 556 keV transitions in Cd114. The conversion coefficient measurements reported here in Cd114 and In114 (Z=48 and 49) and in earlier studies (Z=22 - 28 and 56) indicate that E2-conversion coefficients in the Z region below 60 are in good agreement with theory.
Gas-Solid Interaction
Authors: Sanesi Manlio , Wagner Vittoriano
Published: March 2015

The adsorption of vapours of C6H6, CCl4 and cyclo-C6H12 respectively on γ-Al2O3 is followed by means of electric capacity measurements, and the dielectric isotherms are drawn for the three heterogeneous systems. The shape of the isotherms is discussed, and equations are proposed for calculating the apparent dielectric constants of the adsorbates from the slopes of the isotherms.
Schalenmodellrechnungen beim Kern O18 mit geschwindigkeitsabhängigen Zwei-Teilchen-Potentialen
Authors: Grote Hans
Published: March 2015

The energies of the low lying levels and the absolute position of the ground state of the nucleus O18 are calculated using five velocity-dependent potentials. The calculation is based on the shell model with two outer neutrons in the potential of the Ο16 core. The interaction potential as well as the core potential are fitted to experimental data, leaving no free parameters in the final result.

The wave functions of the harmonic oscillator are used in each case of the five velocity-dependent potentials. An additional computation is carried out using one of these potentials and taking into account the perturbation of the wave functions. It turns out that, for satisfactory application of the velocity-dependent potentials in shell model calculations, this perturbation should be considered.
Paramagnetische Elektronenresonanz von 99Tc(IV) in Hexahalogeno-Komplexen
Authors: Römelt Gerhard
Published: March 2015

The hyperfine structure of 99Tc (IV) in mixed crystals of K2[TcCle] — K2 [PtCl6] and K2 [TcF,] —K2 [PtFe] was measured at 3 cm wavelength and at 1.7°K and 77°K respectively. The parameters of the chloro-complex are gmax =1.9896, gmin =1.9876, Amax=1.361 × 10-2 cm-1, Amin = 1.337 × 10-2 cm-1; in addition to the Δm=0 transitions, the forbidden Δm= ±1 transitions were observed. The parameters of the polycrystalline fluoro-complex were determined to g=3.884, A=3.34 × 10-2 cm-1, B=1.76 × 10-2 cm-1.
Untersuchung der Dynamowirkung einer nichtspiegelsymmetrischen Turbulenz an einfachen Modellen
Authors: Krause F. , Steenbeck M.
Published: March 2015

A turbulent conducting fluid is considered. In the case of homogeneous, isotropic turbulence with no reflection symmetry OHM’S law for the global fields reads i=σ(E+αB), α=const. Evidence is given for dynamo maintenance of the electromagnetic fields by solving the equations of two simple models: The turbulent motion takes place in a sphere, which is embedded in a nonconducting space in the first case and in a conducting space with the same conductivity in the second case.
A Non-Steady-State Method of Measuring the Thermal Conductivity of Transparent Liquids
Authors: Gustafsson Silas E.
Published: March 2015

A plane source method has been developed for non-steady-state measurements of the thermal conductivity of transparent liquids. The plane source is realized by using an electrically heated metal foil, suspended in the liquid. The temperature distribution is described by using the concept of instantaneous heat sources giving a simple expression of the optical path, which is recorded with wave-front-shearing interferometry. The thermal diffusivity is determined simply by measuring the positions of the fringes, locating the points where the gradient of the optical path is constant and knowing the times between two subsequent exposures. The accuracy of the method, which is an absolute one, is demonstrated. The average deviation from the recommended values of the thermal conductivity was found to be 0.37%.
Zerfallszeiten von Molekülionen. II
Authors: Hertel I. , Ottinger Ch.
Published: March 2015

The previously described apparatus for the measurement of decomposition times of short-lived organic ions has been modified. With the improved version the accessible range of times between ionization and decomposition extends now from about 5·10-9 sec to 5·10-6 sec, although in one case times as short as 3 · 10-9 sec could be distinguished. The substances studied were benzonitrile, n-butane, n-heptane and benzene. The logarithm of the differentially measured decomposition rate was plotted versus the logarithm of the time. All of these plots were found to be straight lines, indicating approximate decomposition laws di/dt ∼ t-r. From the empirical parameter r the distribution of rate constants contributing to the overall decay was evaluated. This distribution led to a determination of the function k(E) which describes the increase of the rate constant k with increasing internal energy E in the ion and is an important molecular property, hitherto only calculable under various assumptions. The calibration of the energy scale of k(E) was based on previous measurements of ionization curves of “normal” and “metastable” fragments. The k(E)-curves for butane and heptane are compared with the most recent experimental and theoretical breakdown curves, with generally good agreement with regard to the energy scale and relative rate constants. The absolute magnitude of the rate constants is surprisingly small and the rise with energy quite slow. It appears that for the decomposition of benzonitrile no rate constants larger than 5·108 sec-1 occur. The amount of fragmentation taking place in times shorter than 10-8 sec was accordingly found to be much smaller than generally assumed; in benzonitrile only 35% of all mass 76 fragments present after 10-6 sec are formed within the first 10-8 sec.

For butane and heptane partial mass spectra for an observation time of 10-8 sec could be evaluated. They are significantly different from the ordinary mass spectra due to different decomposition laws for different fragments.

For benzonitrile, the decomposition function was also measured for different electron energies, starting near threshold. The expected result, a decreasing contribution from high rate constants with decreasing Uel, was established and also reproduced by a calculation.
Vergleich der Intensitäten der mit verschiedenen Methoden gemessenen Zerfälle metastabiler Molekülionen
Authors: Ottinger Ch.
Published: March 2015

Relative intensities of ten previously measured metastable transitions in heptane are compared with tabulated values. The discrepancies can be explained by the different mode of observation, namely in an essentially double-focussing spectrometer as opposed to a 180° spectrometer. A detailed consideration of the influence of small amounts of energy set free in the decompositions shows that the resulting peak broadening can influence the measured peak height greatly, while the lateral broadening of the beam, due to the same energies, can be neglected. After correction for these effects the two sets of metastable intensities were found to be much better correlated.
Some Contributions to Polaron Theory
Authors: Dowson A. E. K. , Haar D. ter
Published: March 2015

We give a microscopic derivation of the single-phonon electron-lattice interaction in an ionic crystal usually employed in polaron theory. We then examine the nature of the coupling with the acoustic lattice modes and, for a simple, one-dimensional model, find conditions under which discontinuous changes in the binding energy of an acouston may occur.
Zum Übergang von der Wellenoptik zur geometrischen Optik in der allgemeinen Relativitätstheorie
Authors: Ehlers Jürgen
Published: March 2015

The transition from the (covariantly generalized) MAXWELL equations to the geometrical optics limit is discussed in the context of general relativity, by adapting the classical series expansion method to the case of curved space time. An arbitrarily moving ideal medium is also taken into account, and a close formal similarity between wave propagation in a moving medium in flat space time and in an empty, gravitationally curved space-time is established by means of a normal hyperbolic optical metric.
Quantenstatistik eines Vielteilchensystems mit Coulomb-Wechselwirkungen
Authors: Kremp D. , Schmttz G.
Published: March 2015

Aus der BOGOLJUBow-Hierarchie für die reduzierten Dichteoperatoren wird die Zweiteilchen-Dichtematrix bis zur Ordnung e2 für ein System geladener Teilechn im Gleichgewicht berechnet. Mit dieser Funktion wird dann für den Fall n λ3⪡ 1 die Korrelationsenergie und die freie Energie bis zur Ordnung e4 bestimmt.
Röntgenspektroskopische Untersuchung der chemischen Bindung in Oxiden
Authors: Chun Hans-Ulrich , Hendel Dieter
Published: March 2015

This paper reports about the fine structure in the O—K-spectra of the oxides BeO, MgO, CaO, SrO, BaO, Sc2O5, Y2O3, La2O3, Sm2O3, Yb2O3, NiO and ZnO. The spectra show the satellite lines α3, α4, α5, α6 on the short wavelength side of the main line α1,2 and a shoulder β′ on its long wavelength side. The wavelengths of all lines depend on the nature of the oxide. For the positions of the lines Kα1.2 in the spectra no systematic relation to other data of the oxides is observed. On the other hand the distance of the a4-satellite from the α1,2-line decreases with increasing electronegativity of the metal atom in the oxide. This distance can be used as a measure for the ionic character of the metal-oxygen bond in these compounds.
Eine IR-spektroskopische Untersuchung der Natur der Gruppierung H9O4
+ in Säurelösungen
Authors: Zundel G. , Metzger H.
Published: March 2015

5 μ thick polystyrene sulphonic acid films were investigated by means of IR spectroscopy. The dependence of the integral extinction of the bending vibration of H2O on the number of H20 molecules present per excess proton shows the special nature of the H904
+ group in the network of hydrate structures. The three protons of the central “H3O+” group (see Fig. 2) tunnel in their hydrogen bridges and play the part of the excess proton, while the external water molecules retain their individuality as vibrating groups. The H9O4
+ group must accordingly be represented by the four proton boundary structures shown in Fig. 2. The hydration degree dependence of the extinction coefficient of the H2O bending vibration is discussed.
Dynamics of Water in Crystal Hydrates
Authors: Berthold Ingo , Weiss Alarich
Published: March 2015

The 1H-NMR spectra of Na2S2O62 H20 and Li2S2Oe· 2 H20 single crystals have been investi-· gated at room temperature. The influence on the NMR spectra by the dynamical behaviour of the water molecules is discussed. The direction cosines of the different p—p lines were determined with a modified PAKE formula given by PEDERSEN. The parameters of the librational motions of the water molecules were calculated by the help of infrared data. The equilibrium H —H-distance in the water molecules was found to be 1.52 A.
Interference Functions, Pair Distribution Functions and Electron Transport Properties of Liquid Mercury-Indium Alloys
Authors: Halder N.C. , Wagner C.N.J.
Published: March 2015

X-ray diffraction patterns of liquid Hg-In alloys with 5, 12, 25, 35, 42, 50 and 62 atomic percent In were measured at room temperature (25°C). The interference and radial distribution functions, I(K) and 4 π r2 ρ(r), respectively, were refined by an error analysis program. The position K1=4π sin Θ1/λ of the first peak maximum of I(K) does not change upon alloying, i. e., K1=2.29 A-1. The interference function of In plotted in reduced coordinates K/K1 agrees with that calculated from the hard sphere model with a packing density of 45%. A small asymmetry of the first peak towards larger K values might be discernible in In, whereas the Hg and Hg-In interference functions show a relatively large asymmetry, and their subsequent peaks appear at larger K/K1 values than those of the hard sphere model and In. The interatomic distances r1 and the numbers of electrons ηE in the first coordination shell show only a small deviation from a linear relationship when plotted as a function of concentration.

Since 1(K) for K<2 kF, where kF is the FERMI radius, are rather similar for Hg, In and all measured alloys, the electrical resistivity and thermoelectric power were evaluated using the random model and ANIMALU and HEINE pseudopotentials. The predicted resistivity was found to increase from 30µΩcm for pure Hg to 43 µΩcm for 35 atomic per cent In alloy and then to decrease to 24 µΩcm for pure In. The measured values of the resistivity decrease from 96 µΩcm for Hg to 30 µΩcm for pure In. Beyond the first eutectic composition, i. e., about 35 atomic per cent In concentration, the predicted resistivity curve decreases similarly to the measured resistivity curve. The discrepancy is attributed to the low density of states for Hg at the FERMI level. The predicted thermoelectric power decreases gradually from 1.22 µV/°K for pure Hg to 0.23 µV/°K for 62 atomic per cent In alloy, the value for pure In being 0.59 µV/°K. The measured values of thermoelectric power at 100°C decrease first from -6.5 µV/°K for pure Hg to -7.1 µV/°K for 5 atomic per cent In alloy and then increase to -0.7µV/°K for pure In. The discrepancy in the predicted values has been attributed to the energy dependence term of the pseudopotentials near the FERMI surface, particularly for pure Hg.
On The Brightness Wave of Electroluminescent ZnS (Powders and Single Crystals)
Authors: Levialdi A. , Romeo N. , Saitta G.
Published: March 2015

We describe a new method for analyzing the brightness wave which accounts for the temperature-dependence of the secondary peak, provides a different interpretation of the enhancement effect in ac+dc and gives a more detailed analysis of the spectral composition of the different harmonic components.
Die Temperaturabhängigkeit der Wärmeleitfähigkeiten von gasförmigem Normal- und Ortho-Deuterium bei Temperaturen des flüssigen Wasserstoffes
Authors: Uebelhack W. , Eichenauer W. , Heinzinger K. , Klemm A.
Published: March 2015

The relative difference of the thermal conductivities of gaseous ortho- and normal-deuterium has been measured at three different temperatures 18,5°K, 19,8°K and 21,1°K. The results are 0,97 ·10-3, 1,08 ·10-3 and 1,45 ·10-3 respectively, with an accuracy of ±10%. They are compared with the relative difference of the viscosities for the two deuterium modifications. This comparison leads to a difference in ƒtr and ƒint for ortho- and normal-deuterium in the EUCKEN relation.
Properties of High Lying Levels in 199Au
Authors: Bashandy E. , El-Sayad G. M.
Published: March 2015

The energy level spectrum of 199Au excited in the decay of the 30 min activity of 199Pt was investigated by means of a high resolution, double focussing β-ray spectrometer. The K- and L-conversion ratios of the 196 and 221 keV γ rays show that both are pure E2 transitions. The internal K-conversion coefficients of the 541, 790 and 960 keV γ rays were determined by the internalexternal conversion method, and the following results were obtained:

αK (541) =0.059 ± 0.007; αK (790) =0.023 ± 0.003; αK (960) = 0.062 ± 0.008.

The multipolarity assignments of these transitions were studied on the basis of the conversion coefficients. These data and the studies of other workers were combined to obtain the spins and parities 5/2 +, 1/2 +, 3/2 + and 9/2 + for the 541, 737, 790 and 960 keV levels in 199Au.
Beugung langsamer Elektronen an Oktaederflächen von Magnetit
Authors: Szostak R. , Molière K.
Published: March 2015

A (111) face of a Fe3O4 crystal, after heating to 800°C and cooling down in the ultra-high vacuum of the LEED apparatus, gives a pattern in which the stronger reflection spots of the magnetite structure are surrounded by weak satellites, arranged in a narrow hexagonal network. These may be interpreted as due to multiple diffraction on the Fe3O4-substrate and a very thin (111) layer of a different cubic structure extended epitaxially on the magnetite surface. The lattice constant of the layer would be approximately 53.5% of that of the substrate. - If oxygen (100 · 10-6 Torr · sec) at room temperature is given into the apparatus the satellites disappear and only the magnetic spots are to be seen in the LEED pattern. - The two patterns may be reproduced alternately by heating and oxidizing in the described manner as often as one likes to repeat the cycle.

The surface layer produced by heating in the UHV may be tentatively attributed to a (111) film of a cubic structure similar to that of FeO, having an anomalous lattice parameter parallel to the surface, expanded by 4.5% in comparison with a (111) netplane of a bulk FeO crystal.