bluuebunny/crossref_metadata_2025 huggingface dataset:
Erweiterung der Neuen Tamm-Dancoff-Methode auf Phasen- übergänge in Vielteilchensystemen / Extension of the New Tamm-Dancoff Method to Phase Transitions in Many-Body Systems
Authors: Friederich A. , Gerling W. , Bleuler K.
Published: February 2015

We extend the New Tamm-Dancoff method by introducing intermediate states. In this way we are able to treat with the Green's function method the effect of nearby levels in many-body systems. We formulate the η-and the ζ-function method with intermediate states. Aldready in first order, the ζ-function method yields a whole series of new approximations in addition to known theories such as the Hartree-Fock theory and the Hartree-Bogoliubov theory. As an example we study intensively "the Hartree-Fock theory with intermediate states". The ζ-function method which is based on the η-function method yields in first order in addition to RPA, quasi-particle RPA and other approximations "RPA with intermediate states". We apply the Hartree-Fock theory with intermediate states and RPA with intermediate states to the exactly solvable Lipkin model.
Mikrowellenspektrum, rotationsspektroskopische Konstanten und r0-Struktur des CSFCl / Microwave Spectrum, Spectroscopic Constants and r0 Structure of CSFCl
Authors: Kohrmann Hans Joachim , Zeil Werner
Published: February 2015

The microwave spectra of following isotopic species 12. 12C32S19F35Cl, 12C32S19F37Cl, 12C34S19F35Cl, 13C32S19F35Cl have been measured. The rotational constants and the centrifugal distortion constants have been determined and a r0 structure calculated.

The structure parameters are: rCS 1.595° Å, rCF 1.326° Å, rCCl 1.715° Å, ∢ SCF 123.82°, SCCl 127.12°.
The Interaction of a Large Amplitude Travelling Wave with a Cylindrical Plasma
Authors: Finken K. H. , Stampa A. , Tuczek H.
Published: February 2015

In connection with the problem of radio frequency heating of plasma, the interaction of a high power wave (0.1 GWatts) with a cylindrical plasma is investigated experimentally for frequencies near the ion cyclotron frequency and in the region between the ion cyclotron frequency and the lower hybrid frequency. It is found that a geometric resonance can be excited in which more than 90% of the wave energy is absorbed by the plasma. At frequencies around the ion cyclotron frequency, the macroscopic properties of the plasma, including distortion of the wave by large amplitude effects, can be fairly well explained by a MHD-model assuming an anomalous resistivity. The enlarged collision frequency is attributed to the presence of turbulence which is excited by drift currents connected with the wave.
On Drago's E-C Equation, Pearson's HSAB Rule and the Ionic Approximation to Chemical Bonding
Authors: Van Hooydonk G.
Published: February 2015

An attempt is made to explain the E-C formalism for ionic interactions in terms of the ionic approximation to chemical bonding. Dravo's E-C equation is seen to be a first approximation to the bond energy equation as it is given by the ionic bonding approach. The meaning of the ratio C/E is discussed and its relation with the hardness and softness of interacting species, as these occur in Pearson's HSAB rule, shows that the electron affinity or electronegativity of elements completely determines the chemical behaviour of ionic species. This analysis illustrates the consistency of the ionic approximation to chemical bonding.
The Elastic Constants of a Nematic Liquid Crystal
Authors: Gruler Hans
Published: February 2015

The elastic constants of a nematic liquid and of a solid crystal were derived by comparing the Gibbs free energy with the elastic energy. The expressions for the elastic constants of the nematic and the solid crystal are isomorphic: k ∝ ∣ D ∣ /1. In the nematic phase ∣ D ∣ and I are the mean field energy and the molecular length. In the solid crystal, ∣ D ∣ and l correspond to the curvature of the potential and to the lattice constant, respectively. The measured nematic elastic constants show the predicted l dependence.
Röntgen-Beugungsuntersuchungen an geschmolzenem Tellur / X-ray Diffraction Study of Molten Tellurium
Authors: Hoyer W. , Thomas E. , Wobst M.
Published: February 2015

X-ray Diffraction Study of Molten Tellurium An X-ray diffraction apparatus with focusing geometry used for the investigation of free surfaces of melts and a computer programme for the analysis of scattering intensities are discribed. The results of our measurements on molten tellurium at 480, 550 and 620 °C are presented and compared with a model of the temperature change of the short range order in molten tellurium as described by Cabane, Tourand and Breuil 14-17.

The important result is that the number of nearest neighbours is approximately 3 at all the 3 temperatures. This suggests that the short range order is changing at the melting point from a chain structure to an antimony-like structure.
The Structure of Liquid Silver-Copper Alloys
Authors: Lukens W. E. , Wagner C. N. J.
Published: February 2015

Mo-Kα X-rays have been used as a radiation probe to evaluate the interference functions l(K) (also called structure factors) of liquid Ag, Cu and Ag-Cu alloys with 16.5, 28, 37, 50, 57, 71 and 85 at.% Cu at temperatures about 50 °C above the liquidus. Employing the transmission technique, I(K) has been determined in the range of K = 4 π sin θ/λ between 0.8 and 12.5 Å-1. The partial interference functions Iij(K) have been calculated, and it was found that the assumption of concentration independence of Iij(K) yielded reduced partial distribution functions Gij(r), the weighted sum of which were in excellent agreement with G(r), the Fourier transform of F(K) =K[l(K)-1]. The position of the first peak in G(r) and the coordination number η show a positive deviation from a straight line when plotted as a function of concentration.
Infinite Matrices, Ritz Theorem and Bound State Problems
Authors: Mitra A. K.
Published: February 2015

The straight forward application of the Ritz variational technique has been shown to be a very convenient method for obtaining numerically the first few discrete eigenvalues of the Schroedinger operator with certain special types of potentials. This method solves essentially the (finite) matrix eigenvalue problem obtained by truncating the infinite matrix representing the Schroedinger operator with respect to the Coulomb wave functions. The Ritz theorem justifies the validity of this truncation procedure.
E-Typ-verzögerte Fluoreszenz von Circobiphenyl in einer Kunststoffmatrix / E-type delayed fluorescence of circobiphenyl in a plastic matrix
Authors: Zander M.
Published: February 2015

In 1. c. 1 war gezeigt worden, daß Circobiphenyl (I) die aufgrund seines relativ kleinen S1-T1-Inter-valls von ca. 4kK zu erwartende E-Typ-verzögerte Fluoreszenz zeigt.
Energy Transfer and Superradiance Between Two High Temperature Carbon or Nitrogen Plasmas
Authors: Norton B. A.
Published: February 2015

Efficient superradiant wavelength conversion and focus-sing in the vacuum UV region below 300 Å is described for Carbon and Nitrogen plasmas. In this scheme a plasma containing predominantly Helium-like ions is pumped with optically thick resonance radiation from Hydrogen-like ions in a neighbouring plasma of higher temperature. Such a two-plasma system could exist in the earth's atmosphere, or in the laboratory by irradiating a suitable target with a high-powered laser. The power requirements in the latter case are within present capabilities.
Ionisierungs- und Auftrittspotentialmessungen an Dialkylsulfoxiden
Authors: Potzinger Peter , Stracke Heinz-Ulrich , Küpper Wolfgang , Gollnick Klaus
Published: February 2015

Ionisation- and appearance potentials of some dialkylsulfoxides and their major fragment ions were determined. In addition to the determination of dissociation energies in the ions and heats of formation of the ions and ionic fragments, a value of 66 kcal/mole for the C-S dissociation energy in neutral dialkyl sulfoxides was obtained.
Niederfrequente dielektrische Relaxation von K+-Ionen in der zweidimensionalen Tunnel-Struktur von K3Sb5O14 / Low-Frequency Dielectric Relaxation of K+-lons in the Two-Dimensional Tunnel Structure of Ka5Sb5O14
Authors: Schön Günter , Staudt Ulrich
Published: February 2015

The compound K3Sb5O14 was synthetisized single-phase and examined by means of dielectric spectroscopy from 30 Hz to 10 MHz. Three separate regions of dielectric absorption with broad distributions of relaxation times have been found. Temperature-dependend measurements up to 200 °C yielded enthalpies of activation between 15 and 20 kcal/mole.
Angular Momentum and Discrete Symmetries in the Spinor Bethe-Salpeter Equation
Authors: Bauhoff W.
Published: February 2015

The group-theoretical basis for the angular momentum reduction of the spinor Bethe-Salpeter equation is discussed. We construct amplitude of definite angular momentum by analogy to the nonrelativistic problem and discuss the differences. The additional decomposition because of discrete symmetries is explained. Finally, we relate the states to those obtained in the non-relativistic quark model.
Frequency Dependence of Proton Spin Relaxation in Liquid Crystalline PAA
Authors: Wölfel W. , Noack F. , Stohrer M.
Published: February 2015

We report on measurements of the Larmor frequency dependence of the proton spin relaxation time T1 in the nematic and isotropic phase of p-azoxyanisole (frequency range: 3.8 kHz ≦ ωL/2 π≦75 MHz) . In both cases our results clearly support the Pincus-Cahane mechanism of spin relaxation by order fluctuations ("ωL−½-law") and exclude the alternative translational dif­fusion model (“ωL+½-law”). For the isotropic phase it was possible to evaluate the correlation time τ of the liquid crystalline order fluctuations from the observed T1 dispersion. As a function of the deviation ⊿ν=ν-νc from the critical nematic-isotropic transition temperature, νc= (136± 0.5)°C, we found τ=2.71·10-7-⊿ν-0.25s .
Thermal Instability in Plasma with Finite Larmor Radius
Authors: Sharma R. C. , Prakash Kirti
Published: February 2015

The effects of the finite Larmor radius of the ions on the thermal instability of a plasma are investigated. When the instability sets in as stationary convection, the finite Larmor radius is found to have a stabilizing effect. The conditions for the nonexistence of overstability are investigated. The case with horizontal magnetic field is discussed.
Zur Ladungstrennung bei der sensibilisierten Löcherinjektion in Anthracenkristallen / Charge Separation and Sensitized Hole Injection into Anthracene Crystals
Authors: Michel-Beyerle M. E. , Bube W. , Haberkorn R.
Published: February 2015

The dependence of the sensitized injection current and of the crystal's sensitized delayed fluorescence on the electric and magnetic field is utilized to examine the process of charge separa-tion at the phase boundary crystal/water electrode. Hole currents, sensitized by electron transfer interaction between rhodamine B molecules in their lowest excited singlet state and the anthracene crystal, can be shown to originate from a thermal injection process. This conclusion is further supported by the changed phenomenology of the injection current and the delayed fluorescence in the presence of molecular oxygen in the aqueous electrode. In this case an alternative injection reaction predominates due to the oxygen enhancement of the intersystem crossing rate and thus of the sensitized population of triplet excitons in the crystal, the latter ones injecting holes through electron transfer to oxygen present at the surface.

Neglecting image-and Coulomb forces at the interface crystal/electrolyte, an analytical ex-pression for the current-voltage relation can be given which includes the influence of the space charge. This expression does well agree with the experimental current-voltage characteristics ob-served for different surface recombination rates of charge carriers.
The Conductance of Sodium Perchlorate in Water-sulfolane Mixtures at 35 °C
Authors: Petrella Giuseppe , Castagnolo Maurizio , Sacco Antonio
Published: February 2015

Measurements on the conductance of dilute solutions of sodium Perchlorate, at 35 °C, in water-sulfolane mixtures over the entire solvent composition range are reported. Experimental data were analyzed by the 1965 Fuoss-Onsager-Skinner equations.

No detectable ion association was found for this electrolyte, unlike sodium chloride in the same solvent mixtures. The association order KA(Cl-)>KA(ClO4
-) is in contrast with that observed in protic solvents [KA(ClO4
-)>KA(Cl-)] and is similar to that found in aprotic solvents. This shows that in water-sulfolane mixtures, association phenomena are mainly controlled by sulfolane.

The lack of transport numbers for water-sulfolane mixtures precludes unambiguous explanations for Waiden products A0η.
Focusing of an Intense Relativistic Electron Beam by a Hollow Conical Laser Beam
Authors: Winterberg F.
Published: February 2015

Estimates suggest that the nonlinear transverse radiation pressure produced within a plasma by a convergent annular high power laser beam may lead to the focusing of an intense relativistic electron down to a radius of ~10-4 cm. The transverse radiation pressure results from the dielectric property of a plasma in conjunction with the phenomena of the self-focusing of intense laser light. The tightly focused electron beams would make possible the release of thermonuclear energy by micro-explosions.
Herkunft der kleinen Maxima bei geschmolzenem Au, Ag und bei festem amorphem Ga / Origin of the Small Maxima inAu, Ag, and Ga
Authors: Richter H. , Breitling G.
Published: February 2015

Between the first and second maxima of the atomic distribution curves of molten Au, Ag, and solid liquid-like amorphous Ga a small, but sharp maximum at [r1′] Au, Ag · √2 3.84 Å and [r1] Ga · √3 4.83 Å occurs. Hence [ri′] Au,Ag = 2.72 Å and [ri]Ga = 2.79 Å follows as the shortest atomic distances of structure II and of the spherical close packing (structure I), respectively.

According to the structural model of Richter and Breitling in molten Au and Ag the shortest oblique distance of the square chain I of structure II shows up by the [ri′] Au,Ag· √2-distance. On the other side in solid amorphous Ga the shortest oblique distance of the rhombohedron chain II of structure I appears at the [ri]Ga· √3-distance. In both cases the respective maximum must be very small because of the large variations in distance of the shortest oblique distances.
Investigation of the Structure of the v5 Band of Monofluoroacetylene
Authors: Huhanantti Mikko , Kauppinen Jyrki
Published: February 2015

The rotational structure of the bending fundamental v5 of monofluoroacetylene around 366 cm -1 was investigated. The measurements were performed using a Michelson type Fourier spectrometer with a resolution of about 0.05 cm -1 . The values B0=0.32373 cm -1 , a5
-= - 6.00 x 10 -4 cm -1 , q5= 6.3 x 10 -4 cm -1 and D = 11.2 x 10 -8 cm -1 were obtained from the analyses of the P-, Q-, and R-branches. In addition, some hot bands accompanying the fundamental were studied.
Transporteigenschaften und Quantenoszillationen von Te-und Sn-dotiertem Bi94Sb6 / Transport Properties and Quantum Oscillations of Te- and Sn-Doped Bi94Sb6
Authors: Schneider G. , Trommer R.
Published: February 2015

Electronic transport properties of undoped, Te- and Sn-doped Bi-Sb-alloys of approximate composition Bi94Sb6 were measured within the temperature range 10-300 K. Besides the electrical conductivity and thermoelectric power the magnetoresistance, the Hall effect and the thermoelectric power in a magnetic field were investigated. Measurements in low magnetic fields yield the mobility tensor for Te-doped samples and in connection with the Shubnikov-de Haas oscillations in higher magnetic fields the effective mass tensor of the electrons. Corresponding investigations on Sn-doped p-conducting samples in this paper give the mobility tensors of light and heavy holes and approximately the effective mass tensor. Here quantum oscillations of the thermoelectric power in a magnetic field were analysed.
Notizen: Energy of the Quasi-free Electron State in Liquid Argon, Krypton, and Xenon
Authors: Tauchert W. , Schmidt Werner F.
Published: February 2015

The energy of the conduction state in liquid argon, krypton, and xenon was measured by means of the photo-effect. The data are used to calculate the scattering lengths. The relation between scattering length and electron mobility is discussed.
Notizen: Vacancy Ordering in Anion-deficient LaNiO3
Authors: Gai P. L. , Rao C. N. R.
Published: February 2015

LaNiO3 loses oxygen in well-defined equilibrium stages. Electron diffraction studies show the presence of super-structure due to vacancy ordering in an anion-deficient sample.
Bremsstrahlung and Pair Production in the Field of Free Electrons
Authors: Haug E.
Published: February 2015

A formula is given for the doubly differential cross section of electron-electron bremsstrahlung which is exact in lowest-order perturbation theory. Angular distributions and energy spectra of the emitted photon are calculated in the center-of-mass system and the laboratory system. The cross section for pair production in the field of an electron (triplet production) can be derived from the analogous bremsstrahlung formula using the substitution rule. Angular distributions and energy spectra of the produced positron as well as the total cross section for triplet production are computed in the laboratory system. The results for bremsstrahlung and pair production are compared with previous theoretical calculations
Laser Frequency Stabilization by Means of Saturation Dispersion
Authors: Kramer G. , Weiß C. O. , Helmcke J.
Published: February 2015

A method for frequency stabilization of 3.39 μm He-Ne lasers, which makes use of the saturation dispersion of the v3 , P(7) methane transition is described. It is shown that with lasers which are stabilized by saturation effects, the absorptive and dispersive properties of the saturation resonance are not precisely distinguishable. This leads to a slightly asymmetric resonance and a shift of the apparent line-center. When using the dispersion for stabilization, the asymmetry can be detected and eliminated. Frequency stabilization to the true line center with an accuracy of 5 x 10-12 was attained
Reversible Creation and Annihilation of a Violet Fluorescence Band in Doped ZnS Crystals
Authors: Grasser R. , Roth G. , Scharmann A.
Published: February 2015

Annealing of doped (Cu, Ag, Au) ZnS crystals at 1200 °C and subsequent quenching or slow cooling, respectively, create or annihilate a violet fluorescence band, reversibly. The experimental results indicate that the emission must be due to isolated native defects in the ZnS lattice
Die Protonenresonanz von adsorbiertem Benzol an Zeolithen des Faujasittyps mit verschiedenen Si/Al-Verhältnissen / The Proton Resonance of Adsorbed Benzene in Zeolites of the Faujasite Type with Different Si/Al-ratioes
Authors: Lechert H. , Haupt W. , Kacirek H.
Published: February 2015

At high Si/Al-ratioes of faujasite type zeolites, the cations in S2-position at the walls of the large cages are the prefered centers of sorption. In the present paper, the shape of the resonance lines is studied for samples with Si/Alratioes high enough so that different numbers of these ions can be expected. For samples with Si/Al above 2.43, a narrow line can be observed at high coverages, superimposing the broad line and indicating benzene molecules with a higher mobility, the intensity of which increases with increasing Si/Al-ratio or decreasing number of S2-ions in the large cage. The possible importance of this observation for the catalytic activity of these substances is shortly discussed in connection with results of other authors
On the Fluorescence Quenching of Polycyclic Aromatic Hydrocarbons by Nitromethane
Authors: Dreeskamp H. , Koch E. , Zander M.
Published: February 2015

Fluorescence quenching of 22 polycyclic aromatic hydrocarbons by nitromethane in toluene and acetonitrile solutions has been studied. Contrary to Sawicki’s observations that the fluorescence of hydrocarbons with the fluoranthene skeleton is not quenched that of 11.12-and 3.4-benzofluor-anthene and fluoranthene itself is quenched. These compounds have a high energy of the fluorescence transition. The fluorescence quenching of the compounds investigated follows a dynamic quenching mechanism. The bimolecular rate constant of fluorescence quenching increases exponentially with the energy of the fluorescing state of alternant hydrocarbons.
Notizen:Kernmagnetische Relaxationszeit-Messungen an OH-Protonen einer kristallinen Kieselsäure/ Nuclear Magnetic Relaxation Measurements on the OH-Protons of a Crystalline Silicic Acid
Authors: Wittich E. K.-H. , Voitländer J. , Lagaly G.
Published: February 2015

The transversal relaxation times of the OH-protons of a crystalline silicic acid were measured. Two relaxation processes, clearly separated from each other, are related to the OH-protons in the silicate layers and to the OH-protons of water molecules in the interlayer spaces. From the initial magnetizations information is obtained about the water content in the interlayer space which does well agree with results given in thermal decomposition curves.
Quasi-Implicative Lattices and the Logic of Quantum Mechanics
Authors: Hardegree Gary M.
Published: February 2015

Mittelstaedt has defined the class of quasi-implicative lattices and shown that an ortholattice (orthocomplemented lattice) is quasi-implicative exactly if it is orthomodular (quasi-modular). He has also shown that the quasi-implication operation is uniquely determined by the quasi-implicative conditions. One of Mittelstaedt's conditions, however, seems to lack immediate intuitive motivation. Consequently, this paper seeks to provide a number of reformulations of the quasi-implicative conditions which are more intuitively plausible. Three sets of conditions are examined, and it is shown that each set of conditions is both necessary and sufficient to ensure that an ortholattice is orthomodular, and each set of conditions uniquely specifies the implication operation to be Mittelstaedt's quasi-implication. Various properties of the quasi-implication are then investigated. In particular, it is shown that the quasi-implication fails to satisfy a number of laws associated with the classical material conditional. Various weakenings of these laws, satisfied by the quasi-implication, are also discussed
Kontinuumsstrahlung des einfach ionisierten Helium-Plasmas im Spektralbereich von 300 nm bis 650 nm / Continuum Radiation of a Single Ionized Helium-Plasma in the Spectral Range 300 nm to 650 nm
Authors: Einfeld D. , Sauerbrey G.
Published: February 2015

The radiation emitted from a wall stabilized helium-plasma (ne ≈ 3 • 1022 m-3, T ≈ 38 000 K, duration of constant discharge current 0.4 ms) was investigated in the wavelength range 300 nm to 650 nm. From the emission coefficients of the continuum radiation Gaunt factors for the state with the principal quantum number 3 and the state 2 3P were determined. Gaunt factors for the terms 2 1S, 2 1P, 2 3S and 2 3P were calculated from the transition probalilities of highly excited states. Agreement to within the accuracy of the measurement was found between the experimental results and the Gaunt factors evaluated from the photoionisation cross-sections calculated by Goldberg. The Gaunt factors for the states 2 1P and 2 3S according to Anderson and Griem are in good agreement with our results; for the terms 2 3P and 2 1S a discrepancy exists. With the Gaunt factors reported here electron densities in a helium-plasma can be determined with a relative uncertainty of 10%. The ξ-factor calculated by Kriener and Schlüter could be confirmed, if Bremsstrahlung of neutral atoms is neglected
NMR Spin-Spin Coupling in HD
Authors: Sänger W. , Voitländer J.
Published: February 2015

The contact contribution to the nuclear spin-spin coupling constant in HD is evaluated variationally by using the nonsingular contact spatial part fm(r,a) =exp(-r/a)/2 a3, a=O (10-6) a.u. JHD is calculated to be 39 Hz and is independent of the sharp short-range part of the trial firstorder wavefunction to the order O (a)
A Model of the Structure of Liquid Germanium
Authors: Orton B. R.
Published: February 2015

A model of liquid germanium is proposed based on two near neighbour distances. The observed interference function at 1047 °C is reproduced, within experimental error, by the superposition of only two different partial interference functions which are approximated by hard sphere interference functions of packing density 0.41 and diameters 2.07 and 2.70 Å
Density-Functional Formalism
Authors: Szasz L. , Berrios-Pagan I. , McGinn G.
Published: February 2015

A new Density-Functional (DF) formula is constructed for atoms. The kinetic energy of the electrons is divided into two parts: the kinetic self-energy and the orthogonalization energy where these concepts are borrowed from the pseudopotential theory. For the radial part of the ortho-gonalization energy which replaces the radial part of the Fermi-energy of the Thomas-Fermi model we derived the expression

where p is the momentum, the ak's are constants and pε is the momentum width associated with the self-energy for which an expression is derived. Calculations were made for the total energies of neutral atoms, positive ions and for the He isoelectronic series. For neutral atoms the results match the Hartree-Fock energies within 1 % for atoms with N < 36; for atoms with N > 36 the results generally match the HF energes within 0.1%. For positive ions the results are fair; for the He series we achieved four or five-digit agreement between our energies and the HF results. For molecular applications a simplified model is developed in which the kinetic energy consist of the Weizsäcker term plus the Fermi energy reduced by a continuous function η(N). It is shown that the η(N) can be constructed in such a way that the energies computed closely approximate the HF energies for all neutral atoms.
An Improved Formula for the Radiative Tail in Electron Scattering
Authors: Borie E.
Published: February 2015

An exact formula for the radiative tail in electron scattering is presented in a form more convenient for numerical computation than previous versions.
Electron-Electron Bremsstrahlung in a Hot Plasma
Authors: Haug E.
Published: February 2015

Using the differential cross section for electron-electron (e-e) bremsstrahlung exact to lowest-order perturbation theory the bremsstrahlung spectra and the total rate of energy loss of a hot electron gas are calculated. The results are compared to the nonrelativistic and extreme-relativistic approximations available and to previous work. The e-e contribution to the bremsstrahlung emis-sion of a hydrogenic plasma is found to be not negligible at temperatures above ≈ 108 K, especially in the short-wavelength part of the spectrum.
CNDO-CI-Berechnungen zum Einfluß der N-Acylierung auf das Absorptions-und Phosphoreszenzspektrum von Carbazol/ CNDO-CI Calculations of the Effect of N-Acylation on the Absorption and Phosphorescence Spectra of Carbazole
Authors: Zander Maximilian , Fratev Filip , Olbrich Gottfried , Polansky Oskar E.
Published: February 2015

The observed blue shift of the carbazole chromophore by N-acylation has been verified by CNDO-CI-calculations of fluorene, carbazole and N-formyl-carbazole. From the CNDO-CI results which are in excellent agreement with the experimental data, a detailed analysis of the spectra is derived.
Double Resonance Modulation as a Standard Technique in Microwave Spectroscopy I. Principles and Operation
Authors: Stiefvater Otto L.
Published: February 2015

A versatile spectrometer with facilities for modulation by the microwave-microwave double resonance effect has been constructed for the continued evaluation of the double resonance modulation (DRM) technique. Investigation of the DR signal pattern and intensity for different modes of operation indicates that optimum results are achieved with a large frequency modulation of the pump radiation, and with one pump frequency precisely on resonance. The high sensitivity of the DRM spectrometer to the effects of not exactly resonant pump radiation leads to the occurrence of multiple double resonances (DRs) and makes double resonance double search experiments practicality feasible. The double resonance map is introduced as a convenient means for the presentation of DR-spectra, and miscellaneous practical aspects are reported.
Notizen: Magnetische Wechselwirkung der Elektronen/ Magnetic Interaction of Electrons
Authors: Heitzmann Martha
Published: February 2015

Magnetic Interaction of Electrons Electrons have, besides their charges, spins with magnetic dipolmoments. Therefore there are also magnetic forces, attractive or repulsive, between these particles at low distances. According to the position of the moments there is a distance in which the magnetic attraction has the same absolute value as the electric repulsion and will be larger at lower distances. This is discussed in the context of the formation of atoms, negative ions and molecules.
Notizen: Abschätzung der Lebensdauer des 317,9 keV- Zustandes in 129Xe/ Lifetime Estimation of the 317.9 keV-Level in 129Xe
Authors: Engel H. , Gerst E. , Schneider H. , Spitz R.
Published: February 2015

The 93.5 keV-317.9 keV-cascade was used in a delayed γ-γ-coincidence experiment to measure the lifetime of the 317.9 keV-level in 129Xe. The excited states of 129Xe were populated by the decay of 129Cs. A combination of a NaI (Tl) -and a Ge (Li) -detector was used. The evaluation of data resulted in the following estimation

T½(317.9 keV-level, 129Xe) < 500 ps.
Irreversible Thermodynamics of Nonequilibrium Alignment Phenomena in Molecular Liquids and in Liquid Crystals
Authors: Hess Siegfried
Published: February 2015

To treat nonequilibrium alignment phenomena in molecular liquids and in liquids crystals two points of the usual irreversible thermodynamics have to be modified. Firstly, in the specific energy a term quadratic in the alignment tensor is included. Secondly, terms up to 4th order in the alignment are taken into account in the entropy for a nonequilibrium situation. Then the entropy production is calculated. Constitutive laws are set up for the friction pressure tensor and for the tensor which characterizes the decay and the production of the alignment in the balance equation for the alignment tensor. As a first application, the nonlinear relaxation equation for the alignment is considered. For a uni-axial alignment zero and nonzero stable stationary values of the order parameter are found for temperatures above and below the temperature TK at which the transition from the isotropic to the nematic phase takes place. Small deviations from the equilibrium alignment decay exponentially. For temperatures below TK the relaxation time turns out to be anisotropic. In the appendix, the entropy associated with the alignment is calculated for a special case.
Calculations and Measurements of the Dynamic Stark Effect in Hydrogen
Authors: Rutgers W. R. , Kalfsbeek H. W.
Published: February 2015

A theory is given for the spectral profile of the first hydrogen Balmer line when the radiating neutral atom is under influence of both (quasi-) static and harmonically oscillating electric fields. Profiles, measured in a turbulent heating experiment, show a series of intensity maxima on the wings of the Balmer lines. If we assume a model for the spatial distribution of turbulent wave vectors, we can derive the fieldstrength and the direction of low-frequency (ion-acoustic) oscillations and the strength and frequency of high-frequency (Langmuir) oscillations.
ESR of Gamma Irradiated KHSO4 Single Crystal
Authors: Köksal F. , Yüksel H.
Published: February 2015

Potassium hydrogen sulphate single crystal has been γ-irradiated at room temperature and its electron spin resonance spectrum recorded by changing the H0 static magnetic field, around an orthogonal axes system. The electron spin resonance spectrum is a single line with a slightly anisotropic g factor. The paramagnetic species has been identified as SO3
- and the principal values of the g tensor has been determined as g1=g2=2.0060, g3 = 2.0045. Direction cosines of the principal

values of the g tensor with respect to the chosen axes have been determined. The spin-orbit contribution to the g-factor has been explained.
A Molecular Dynamics Study of Aqueous Solutions II. Cesium Chloride in H2O
Authors: Vogel P. C. , Heinzinger K.
Published: February 2015

Results of a molecular dynamics study of an aqueous CsCl solution are reported. The system consisted of 216 particles, 200 water molecules, 8 cesium ions and 8 chloride ions and was run over 8000 time steps equivalent of 9 · 10-13 sec. On the basis of radial pair correlation functions, average potential energy of the water molecules and pair interaction energy distribution the static properties of the first hydration shells of the ions are discussed in detail. The self diffusion coefficient for the water molecules is calculated and compared with NMR measurement as well as with molecular dynamics calculations for pure water at elevated temperatures and pressures.
X-Ray Diffraction Study of HCP Metals II. Line Broadening in Polycrystalline Zn and Mg Powder
Authors: Halder N. C. , Johnston E. E.
Published: February 2015

Microstructures of polycrystalline hexagonal close packed (hep) Zn and Mg have been studied by x-ray diffraction line broadening analysis using the integral breadth method, and the Fourier coefficient method. For these two methods, several diffraction peaks were considered to obtain two suitable peak combinations. For the room temperature powder samples, the root mean square (rms) strain was observed to be extremely small. The particle size was anisotropic in both samples with the Zn powder showing more particle size variation than Mg. The average particle size for Zn was about 750 Å, which was over twice the average particle size of 295 Å observed in Mg. The two fault probabilities for Zn turned out to be negligible or zero. Mg, on the other hand, was found to have small, but definite fault probabilities. The deformation fault probability a was 4.5X10-4 and the growth fault prob-ability β was 6.5X10-4 . These results can be compared with the previous work of hep Cd at room temperature, which was found to have no growth fault probability β and a deformation fault prob-ability a amounting to 3X10-3 . This value is higher than that observed in Mg, because for Cd the two fault probabilities were obtained by neglecting the particle size of about 650 Å which actually did exist in the sample.
Analysis of Conducting and Insulating Surfaces by Means of Secondary Ion Mass Spectrometry (SIMS)
Authors: Paz M. De , Macciò C.
Published: February 2015

Using a simple home built apparatus, the surface contamination of various samples maintained at high vacuum conditions is investigated by means of SIMS technique. On a polycrystalline copper surface, at a sample temperature of about 140 K, residual water vapour condensation occurs and ions H+(H2O)n with 1≦n≦11 appear in the positive ion spectrum. On the contrary, on a LiF crystal no water contamination is observed down to 120 K; moreover, on a KI sample, one of the most hygroscopic salts among the alkali halides, only at 130 K an appreciable H2O contamination is detected.
Relative O(1D) Quantum Yields in the near UV Photolysis of Ozone at 298 K
Authors: Moortgat G. K. , Warneck P.
Published: February 2015

Mixtures of O3 with excess N2O were photolysed in the wavelength region 290 - 335 nm using monochromatic light with a band width of 4 nm. The resulting primary product atomic singlet oxygen, O(1D), in reacting with N2O produces in part NO which subsequently reacts with O3 giving rise to a weak infrared chemiluminescence. The emission was monitored with a cooled photomultiplier. The emission intensity is directly proportional to the rate of O(1D) production and it has been utilised to derive the relative O(1D) quantum yield as a function of wavelength between 295 and 320 nm. The data were normalised to a quantum yield of unity of 300 nm and corrections were applied to reduce the error resulting from the spectral band width of photolysing radiation. The O(1D) quantum yields show a temperature dependence. At 298 K the quantum yield is unity up to 305 nm, then declines to zero at 319 nm. At the dissociation limit, taken to occur at γ = 310.3 nm, the quantum yields is 0.57, i. e. considerably below unity. The implications of this result as well as the tail toward longer wavelengths and the temperature dependence are discussed. Ozone absorption cross sections are also reported.
Beweglichkeit und Bildung von Cluster-Ionen im eigenen Gas in He, Ne und Ar unter hohen Drucken
Authors: Heide R. von der
Published: February 2015

A time-of-flight technique is used for the measurement of positive ions mobilities in helium, neon and argon in the 1 - 25 atm pressure range at 25 °C. The reduced mobilities b0 vary with the reduced electric field E/p0 and exhibit different saturation values, which are interpreted in terms of the Langevin theory and connected with the formation of cluster ions:

He+
33 (b0 = 7.4 cm2/Vs), Ne+
13 (3.1), Ne+33 (2.25), Ar+
13 (1.23) and Ar+
33 (0.82).

In Argon also the reduced mobility of Ar+ and Ar+
2 were measured: b0 = 1.56 and 1.84cm2/Vs.
Electron Spin Relaxation of (Diphenyl) in Dimethoxyethane
Authors: Köksal F. , Krüger G. J.
Published: February 2015

The electron relaxation times T1 and T2 have been measured by ESR pulse techniques in solutions of normal and perdeuterated (diphenyl)- in dimethoxyethane at various radical concentrations and temperatures. The results are discussed in terms of different relaxation mechanisms. The most important contribution to spin-lattice relaxation at high concentration is dipolar interaction with other radical electrons modulated by translational diffusion. Spin-spin relaxation has in addition contributions from electron exchange and ion pairing.
Bilokale Feldtheorie der Elementarteilchen
Authors: Vollendorf F.
Published: February 2015

The basic idea of this article is that in a bilocal field theory the Lorentz group can be replaced by the larger group SO (4;4) which contains SO (3;1) as a subgroup. On this basis a system of 24 coupled differential equations is introduced. In the special case of the pion the connection with the local field theory is discussed. It turns out that the application of the local field theory is limited by the reduced Compton wave length λ/2 π of the pion.
Effect of Anisotropy on the Critical Behaviour of Three- Dimensional Heisenberg Ferromagnets
Authors: Shanker R. , Singh R. A.
Published: February 2015

The anisotropic nearest-neighbour Heisenberg model for the simple cubic lattice has been investigated by interpolating the anisotropy between the Ising and isotropic Heisenberg limits via general spin high-temperature series expansions of the zero-field suspectibility. This is done by estimating the critical temperature (Tc(3)) and the susceptibility exponent γ from the analysis of the series by the Ratio and Pade approximants methods. It is noted that Tc(3) varies with anisotropy while γ is almost the same for the anisotropic system, and a jump in it occurs for the isotropic case in agreement with the universality hypothesis. The effect of anisotropy on the susceptibility is also shown. Further, it is seen that estimates of γ for the two extreme limits agree well with those of previous theoretical as well as experimental investigations. In addition, critical temperatures have been summarised in a relation, and expressions for the magnetisation have been derived.
The Microwave Spectrum of 2,6-Difluoropyridine
Authors: Stiefvater Otto L. , Lui Stephen , Ladd John A.
Published: February 2015

Hyperfine splittings of rotational transitions of 2,6-difluoropyridine have been analysed to yield the 14N quadrupole coupling constants. Their values are:

Χaa = 1.82 ± 0.05 MHz, Χbb = - 4.16 ± 0.02 MHz, Χcc = 2.34 ± 0.05 MHz. The electric dipole moment has been determined from Stark effects as fi = 3.82 ± 0.06 D, and satellites in the rotation spectrum have been correlated with the five lowest fundamental vibrations of this molecule.

The dipole moment, the quadrupole data and the structural differences between 2,6-difluoropyridine and pyridine itself can all be accounted for by the change in the electron distribution due to the fluorine substituents.
Zum Mechanismus der 6JHH-Kopplungen in bicyclischen Systemen
Authors: Sterk H. , Wachmann A.
Published: February 2015

Concerning the Mechanism of 9 JHH Couplings in Bicyclic Systems Experimental investigations on bicyclic aromatic systems show the missing of an exocyclic long range coupling. The explanation for this fact can be found by assuming that the through space mechanism owns a greater influence on the amount of the long range coupling constants. On the basis of the different amounts of through space interaction between para-and exocyclic couplings the experimental results can be explained.
ESR of Paramagnetic Species Produced by Gamma Irradiation in Cadmium Oxalate Three Hydrate Single Crystal
Authors: Köksal F. , Yiiksel H.
Published: February 2015

Paramagnetic species produced in a single crystal of cadmium oxalate three hydrate (CdC2O4 · 3H2O) by gamma irradiation have been investigated with the method of electron spin resonance. Only one radical species was observed at room temperature. Analysis of the experimental results leads to the conclusion that the species has the form RCHOH in which the unpaired electron is concentrated at the carbon atom and interacts with the two hydrogen atoms. The ESR pattern was observed nearly undiminished for more than three months after the irradiation. The g factor was found to be only very slightly anisotropic with an average value of 2.0124. The hyperfine interaction tensors of the unpaired electron with the two H nuclei have been determined.
Stöße zwischen Thalliumatomen im 62D-Zustand und Molekülen
Authors: Gelbhaar B. , Hanle W.
Published: February 2015

Energy transfer between the 62D3/2 and 62D5/2 energy levels of thallium, induced by Tl-H2 and Tl-N2 collisions have been investigated. The following cross sections for energy transfer Q(62D3/2 → 62D5/2) and quenching Q(62D3/2) have been determined:

Tl-H2: Q(62D3/2 → 62D5/2) = 87 · 10-16 cm2; Q(62D5/2) = 43 · 10-16 cm2;

Tl-N2: Q(62D3/2 → 62D5/2) = 71 · 10-16 cm2; Q(62D5/2) = 94 · 10-16 cm2.
Präzise Bestimmung von freien Wirkungsquerschnitten für Neutronen / Precision Measurements of Free Cross Sections for Neutrons
Authors: Waschkowski W. , Koester L.
Published: February 2015

Rotating activation foils with resonance energies of 1.26 eV and 5.19 eV have been applied for exact measurements of neutron cross sections. The detector consisted of a sandwich of two rotating foils and was suitable for determining exactly the neutron flux at the resonance energy and energy changes in the neutron beam. The cross sections of polycrystalline samples showed uncertainties greater than the statistical error. The more accurate measurements on liquid samples yielded the following scattering cross sections of free atoms for neutrons of zero energy:

Lead: σ0(Pb) = (11.261 ±0.006) b,

Bismuth: σ0(Bi) = (9.300±0.003) b, and

Sulfur: σ0(S) = (0.985 ±0.004) b.

These data are of interest for an investigation of the neutron-electron interaction.
Der effektive Spin als Modell zur Beschreibung von ESR- Hyperfeinspektren polykristalliner Systeme / The Effective Spin as a Model to describe ESR-Hyperfine Spectra of poly cry stalline Samples
Authors: Dräger K.
Published: February 2015

Paramagnetic ions with hyperfine interaction generally have an involved ESR-spectrum. For host lattices of cubic symmetry it will be shown that while going from single crystals to powdered systems the true spin quantum number S can be substituted by an effective spin quantum number S' = ½. Using an isotropic spin Hamilton operator the energy-levels and their eigenfunctions as well as the transition probabilities are calculated explitely.

The model is then applied to the ESR-spectrum of manganese-doped polycrystalline CaO. The theoretical spectrum fits the experimental up to 2·10-5 and is in every respect comparable to results of the 3rd order perturbation theory. Above all the model reproduces the true values for the g-factor and the hyperfine coupling constant A as known from single crystal investigations. This is also verified for Mn2+ -ions on cubic sites of MgO and BaO.
Die Struktur epitaktisch aufgedampfter Goldfilme
Authors: Fischer W. , Wißmann P.
Published: February 2015

The texture of 400 Å thick gold films was investigated by plotting the intensities obtained with the help of a texture analyser in a pole figure diagramm. The films had been evaporated under UHV conditions on (111)-, (110)-and (100)-oriented silicon substrates.

The gold films always show a preferred (111)-orientation. This preferred orientation, however, may manifest itself in a (111) fibre texture or a single crystal structure due to different orientation and heating pretreatment of the substrate. Quantitative statements are given on crystal misorienta-tion and azimuthal alignment. The sixfold symmetry of the pole figures can be traced back to the influence of twin stacking faults.
Spektroskopische Messung der radialen Temperaturverteilung in Quecksilber-Hochdrucklampen mit Metallhalogenzusätzen / Spectroscopic Measurement of Radial Temperature Distribution in High-Pressure Mercury Lamps with Metal Halide Additives
Authors: Albrecht H. , Schiff A.
Published: February 2015

The radial temperature distribution in a Hg-high-pressure discharge with metal halogene additives (Sn-, Zn-Iodide) has been measured. Three different spectroscopic methods (Emission-, Absorption-, Bartels-and 2-lines-Method) are compared. The influence of the silica bulb is discussed. High incidence angles for the absorption measurements are realized by use of an elliptic mirror. Emission and absorption measurements in a definite time intervall of the 50 Hz-discharge current was done with signal averaging technique. The arc shows a constriction which is discussed.
NOTIZEN: Energies of Muonic Transitions in Cd and Br and Energies and Intensities of Nuclear Transitions in 78Se and 80Se
Authors: d'Oliveira A. Brandão , Egidy T. von
Published: February 2015

The energies of the muonic 2−1 and 3−2 transitions in Cd and Br have been measured. The c-parameter of the (c, t) Fermi distribution was determined. Energies and inten-sities of nuclear gamma rays in Se are given.
A Simple Variational Method for Quantitative Assessment of "Through-space" and "Through-bond" Interactions
Authors: Schmidt Hartmut , Schweig Armin
Published: February 2015

A simple method is described for separating "through-space" from "through-bond" interactions. The method is applied to 1,4-cyclohexadiene, 2,5-dihydrofuran, 2,5-dihydro-thiophene, and 2,5-dihydropyrrole.
Mittlere Schwingungsamplituden der Tetrahalogeno-Aluminate / Mean Amplitudes of Vibration for the Tetrahalogeno Aluminates
Authors: Baran Enrique J.
Published: February 2015

Mean Amplitudes of Vibration for the Tetrahalogeno Aluminates Mean amplitudes of vibration for the A1X4~ ions (X = F, CI, Br, I) have been calculated from known spectroscopic data, using the L-Matrix Method. The results are briefly discussed, especially in relation with those of isoelectronic species.