bluuebunny/crossref_metadata_2025 huggingface dataset:
Notizen: Low Temperature Magnetic Susceptibility of Sm2(WO4)3
Authors: Lal H.B. , Dar Naseeb
Published: February 2015

The magnetic susceptibility of powder samples of Sm2(WO4)3 has been measured in the temperature range 4.2 to 300 K. At low temperatures the measured values disagree with those calculated for Sm3+-ions using Van Vleck's theory. The high values below 100 K are assigned to magnetic exchange and dipol interactions. There might be magnetic ordering below 4.2 K. The effects of the crystal field and impurities have been shown to be unimportant.
Studies by the Electron Cyclotron Resonance(ECR)-Technique IX: Interactions of Low-Energy Electrons with the Molecules CH2Cl2 and CHCl3 in the Gas Phase
Authors: Christodoulides A. A. , Schumacher R. , Schindler R. N.
Published: February 2015

The capture of thermal electrons by the molecules CH2Cl2 and CHCl3 is reinvestigated and discussed. An attempt is presented to describe the reaction path in terms of potential energy diagrams.
Höhere Triplettanregungszustände von Fluoren, Carbazol und Benzologen: CNDO-CI-Berechnungen und Triplett-Triplett-Absorptionsmessungen
Authors: Fratev F. , Hermann H. , Olbrich G. , Polansky O. E. , Zander M.
Published: February 2015

CNDO-Cl calculations of triplet-triplet excitation energies on fluorene, carbazole and their monobenzologues are in good agreement with the results from triplet-triplet absorption measurements. An assignment of the observed triplet data is given. It is shown that the quantum-chemical treatment should be useful in cases where the experimental data are difficult to obtain.
Dipole Centres in Rare-Earth-Doped CaF2
Authors: Kiessling J. , Scharmann A.
Published: February 2015

The reorientation of dipole centres in CaF2: RE3+ (RE: Gd, Tb, Lu) is investigated by the method of ionic thermocurrent (ITC). ITC peaks below 200 K are caused by reorientation of RE3+-F--complexes and related dipole centres, whereas peaks above 200 K seem to be of other origin. Both types of ITC peaks cannot be discriminated by polarization field strength dependence.
Korngrößenabhängigkeit der Ummagnetisierungsvorgänge im Reineisen
Authors: Deimel P. , Röde B. , Wislaug R.
Published: February 2015

The Barkhausen-Spectra of pure iron have been measured for four recrystallized wire specimens of different grain size. The pulse size distributions show a strong dependence on this parameter. The number of the Barkhausen-pulses increases with decreasing grain size. The comparison of the spectra measured at an external field in the vicinity of the coercive force with those measured at a field where domain rotation begins shows that in the latter region the size and number of jumps is larger. Measurements of the counting rate of the Barkhausen jumps versus the external magnetic field show two maxima instead of normally one at the coercive force. This unusual behaviour could be explained with the successive change of Bloch wall types in certain sections of the hysteresis loop and their different interaction with dislocations.
Über die doppelbrechende und die piezo- elektrische Phase von Mischkristallen von NH4Cl oder NH4Br mit Partnern mit gleichem Anion / The Birefringent and the Piezoelectric Phase of Mixed Crystals of NH4Cl or NH4Br with Partners Having the Same Anion
Authors: Brauer Peter , Bußmann Annette
Published: February 2015

Previous investigations of the range of the birefringent phase of mixed crystals having at room temperature the symmetry Pm3m of NH4Cl or NH4Br with simple halides of monovalent cations and the same anion are extended to the nonisomorphic partners KBr, RbBr or RbCl. The disappear-ance of the inversion symmetry in the cubic low temperature phase has been proved by experiment.
The Rotational Spectrum of Monothioformic Acid. II. cis-and trans-HC(:O)SD, DC(:O)SH, HC(:O)34 SH1,2
Authors: Hocking William H. , Winnewisser Gisbert
Published: February 2015

The rotational spectra of three isotopically substituted species of monothioformic acid, DCOSH, HCOSD, HCO34SH, have been investigated. Transitions arising from two different isomeric forms have been observed in each instance. Rotational constants and quartic centrifugal distortion constants have been determined for all species using Watson’s reduced Hamiltonian. It has been established that the two abundant isomers of monothioformic acid are the planar cis and trans thiol rotamers. The structure of cis-HC ( :O ) SH is found to be: r ( C - H ) =1.100 Å, r ( S - H ) =1.336 Å, r ( C - S ) =1.771 Å, r(C=0) =1.210 Å, ∢(OCS) =122.4°, ∢(HSC) =94.7° and ∢(HCS) = 114.6°; whereas for trans-HC ( :O ) SH: r(C - H ) =1.100 Å, r (S - H) =1.351 Å, r (C - S) = 1.763 Å, r(C=O) = 1.218 Å, ∢(OCS) =126.0°, ∢(HSC) = 92.7 ° and ∢(HCS) =111.8°.
Matrix Elements of the Lorentzian Term
Authors: Rao Ch. V. S. Ramachandrá
Published: February 2015

Recursion formulae for the matrix elements of the Lorentzian term 1/(C2 + q2) as well as 1/(C2 + q2)2, on the basis of harmonic oscillator eigenfunctions, are obtained. A practical application where these formulae would be useful is discussed
Thermostatik der Elektrolytlösungen / Thermostatics of Electrolyte Solutions
Authors: Ehrsam Christian
Published: February 2015

To overcome certain difficulties arising in connection with the application of thermodynamics to systems with electrolytes, a model for electrolyte solutions is proposed which can be analysed in terms of thermostatics. On the basis of this model, a thermostatics of electrolyte solutions is developed. The electrochemical potential μ̃ appears as the composite quantity μ + z F λ0, where μ (the chemical potential) and λ0 are Lagrange multipliers. The usual definition of μ̃ is found to be questionable
Anisotropie der elektrischen Leitfähigkeit verschiedener Elektrolyte in einem nematischen flüssigen Kristall / Anisotropy of the Electric Conductivity of Several Electrolytes in a Nematic Liquid Crystal
Authors: Heppke G. , Schneider F.
Published: February 2015

The electric conductivity of twelve electrolytes dissolved in a nematic liquid crystal is investigated. The anisotropy ratio of the electric conductivity varies between 1.23 and 1.68 at room temperature, the highest values being caused by elongated ions. For some of the electrolytes the temperature dependence of the anisotropy ratio indicates the presence of cybotactic groups in the nematic phase
The Problem of Runaway Solutions in the Lorentz-Dirac Theory
Authors: Sorg M.
Published: February 2015

A rigorous non-existence proof for runaway solutions in the finite-size model of the electron is given. Since a consistent point limit, such as the Lorentz-Dirac equation claims to be, should not exhibit features which are completely missing in the more general theory of finite extension, it is proposed that the point-like approximation of the finite-size theory be the integrodifferential formulation of the Lorentz-Dirac theory. This point of view is supported by a new discussion of the hyperbolic motion in the latter theory.
Wiek-Regeln mit Zwischenzuständen und die Neue Tamm-Dancoff-Methode mit Zwischenzuständen / On Wick Rules with Intermediate States and the New Tamm-Dancoff Method with Intermediate States
Authors: Friederich A. , Gerling W.
Published: February 2015

Instead of emphasizing the ground state as is done in Green's function method, we take a finite-dimensional subspace of the Hilbert space: the space of the "intermediate states". A systematic introduction of intermediate states is effected by an extension of the method of generating functionals: we combine the generating functionals of the n-point Green's functions to a "matrix functional" T, and form new matrix functionals, which are matrix functions of T. The aim of this paper is to develop the functional calculus in such a way that the transition from scalar functionals to matrix functionals is straightforward, and the method of obtaining further results becomes clear. Following the lines of Dürr and Wagner we get u η-and ζ-rules with intermediate states". Using them we define a truncation procedure for the equations of motion of the n-point Green's functions, the "New Tamm-Dancoff method with intermediate states". This extension makes it possible to treat the effect of nearby levels in many body systems with Green's functions. In ad-dition to well-known approximations, such as the Hartree-Fock and the Hartree-Bogoliubov theory, the RPA and the quasiparticle RPA, we obtain a series of new approximations. Among these are the "Hartree-Fock theory with intermediate states" and the "random-phase approximation with intermediate states", which we already applied with great success to some exactly soluble models.
A Theory of the Excess Chemical Potential of Metals in Alloys as Related to Electrochemical Measurements
Authors: Leribaux Henri R.
Published: February 2015

Recent measurements of electromotive forces in electrochemical cells have shown the feasibility of measuring relative chemical potentials of alloy components. The excess chemical potential is formulated from the excess Gibbs free energy ⊿GE = ⊿UE+P ⊿VE-T ⊿SE (at constant P and T). The excess internal energy ⊿UE is evaluated from the structure-dependent internal energy of the metals. T ⊿SE is taken as zero (to a good approximation in lithium-magnesium). P ⊿VE is found to be negligible at atmospheric pressure. A calculation is made for the alloy Li-Mg at about 600 °C for the excess chemical potential

where Ni is the number of lithium ions, which is found to be of the right magnitude compared to two sets of experimental results.
Time Reversal Behaviour and Reciprocity Theorem of Transport-Relaxation-Equations
Authors: Waldmann L.
Published: February 2015

The coefficient matrices in the transport-relaxation-equations (moment equations of generalized thermo-hydrodynamics) depend on the polynomials used in the expansion of the underlying kinetic equation. The known behaviour under time reversal of these polynomials, Eq. (7), entails symmetries of the fore-mentioned coefficient matrices, Eqs. (12) and (16). From these symmetries a reciprocity theorem for two stationary solutions of the transport-relaxation-equations is derived, Eqs. (21 a und b) : the divergence of a certain vector field, bilinear in the two solutions, vanishes. The relaxation matrix does not appear in this form. The theorem is useful for investigating the proliferation of the Onsager symmetries from the basic differential equations into the linear algebraic relations between the few global quantities governing “discontinuous systems”. A simple example in heat conduction is worked out. A more complicated case and the role of a magnetic field are briefly considered. Equivalent with (21 a) is the kinetic reciprocity theorem (40).
Theory of Dispersion Energy and Solvent Effects on Molecular Spectra
Authors: Mahanty J. , Rao C. N. R.
Published: February 2015

The theory of dispersion energy has been shown to directly give an explicit expression for the solvent shifts in the spectra of non-polar solute molecules.
Transanular Interaction in [2.2]Phanes: [2.2](2,7)Pyrenophane
Authors: Schweitzer D. , Hausser K. H. , Kirrstetter R. G. H. , Staab H. A.
Published: February 2015

The emission spectra of [2.2] (2,7) pyrenophane and the zero field splitting parameters D und E of its excited triplet state were measured in glasses and in small single crystals at 1.3 K. The results are being compared with monomer pyrene and 2,7-dimethylpyrene in liquid and solid solutions as well as in single crystals.
Millimeter Wave Spectrum of Excited Vibrational States of Potassium Hydroxide, KOH and KOD
Authors: Pearson E. F. , Winnewisser B. P. , Trueblood M. B.
Published: February 2015

Rotational transitions in the millimeter wave region are reported for a number of excited vibrational states of KOH and KOD. From an analysis of the J-dependence of the l-type resonance interactions the separation of the l sublevels of several ν1 ν2
l 0 states has been obtained. The cubic anharmonic contributions to α1 and α2 were determined and the sign and isotopic variation of α2 are shown to be consistent with a nearly harmonic bending potential function. An re structure has been determined from the data using a calculated value for α3 . On the basis of the present data, a severely anharmonic bending potential function for KOH can be excluded. Our results are compared with those for the heavier alkali hydroxides.
On Hyperfine and Fine Structure of Excited Charge-Transfer-Complexes
Authors: Möhwald H. , Böhm A.
Published: February 2015

The charge-transfer (CT)-crystal naphthalene (N)-1,2,4,5-tetracyanobenzene (TCNB) was doped with various guest acceptors. CT-complexes of these acceptors with N are formed acting as a triplet energy trap in the crystal. This provides a method to investigate oriented CT-complexes ESR-spectroscopically. In favorable cases the hyperfine structure (Hfs) in the ESR-spectra can be resolved and interpreted. The Hfs of the complexes N-hexacyanobenzene and N-pentacyano-toluene show that in the crystalline complex the triplet electrons are distributed over no more than two molecules. This finding suggests a strong exciton-phonon-coupling which causes a breakdown of the inversion symmetry upon excitation. The spectra of naphthalene-s-trinitrobenzene (TNB) yield the spin density on the three equivalent protons of TNB and demonstrate that the triplet electrons are also equally distributed over the three nitrogen atoms.

As further systems, complexes of extremely large CT-character, c1
2, in the triplet state are studied (e. g. N-chloranil).

The data obtained from the measurements of the Hfs-and of the zero-field-splitting (ZFS) -parameters are compared, proving that previous models and approximations in deriving c1
2 are essentially correct. It is also shown that the ZFS-parameter D (A+D+) of the hypothetical purely ionic state is negative and for different complexes its value is very close to that obtained in earlier theoretical calculations (-0.027 cm-1).
Three-Dimensional Electron Microscopy of Individual Biological Objects Part III. Experimental Results on Yeast Fatty Acid Synthetase
Authors: Hoppe W. , Schramm H. J. , Sturm M. , Hunsmann N. , Gaßmann J.
Published: February 2015

Experimental results of three-dimensional reconstructions of individual fatty acid synthetase (FAS) molecules are reported. The discussion of the structures has been concentrated on the symmetry relations within the molecules. A molecular structure with 6 copies arranged in point group 32 is probable. The limits of minimal radiation dose reconstruction are estimated.
Oxygen Isotope Effect on 55Mn Nuclear Magnetic Shielding in Permanganate
Authors: Haase A. R. , Lutz O. , Müller M. , Nolle A.
Published: February 2015

By Fourier transform NMR spectroscopy the 55 Mn resonance lines of the different permanganate species

55Mn 16O4-n
18On
- (n=0, 1, 2, 3, 4)

have been resolved in aqueous solutions of potassium permanganate. An isotope effect on the Larmor frequency of 55 Mn of (0.599 + 0.015) ppm to lower frequency was found for the substitution of an 16O atom by an 18O atom in the permanganate ion. An oxygen exchange rate in the permanganate-water system is given.
Pion Mass Difference in Bars-Halpern-Yoshimura Unified Gauge Model
Authors: Sinha Satya N.
Published: February 2015

Pion mass difference has been calculated in the renormalizable gauge model of Bars-Halpern-Yoshimura. It is found that the soft pion mass difference is finite in the lowest order perturbative calculation, similar to the result obtained in the unified model of Salam-Weinberg. The mass difference of Kaon has also been discussed.
Initial-Value Problem for the Non-local Generalization of the Lorentz-Dirac Equation
Authors: Sorg M.
Published: February 2015

Although the equation of motion, recently proposed for the classical radiating electron, is of non-local character in proper time, the Newtonian initial data (position and velocity) are sufficient to guarantee existence and uniqueness of the solutions. The corresponding existence proof is accomplished by the Picard-Lindelöf method of successive approximations. This method indicates the possibility of a perturbation expansion of the exact solution in terms of the non-locality parameter. Such a perturbation expansion does not seem to be possible in the Lorentz-Dirac theory.
Inverse Operator Technique for Treating Senftleben-Beenakker Effects without Using the Spherical Approximation
Authors: Köhler W. E. , Knaap H. F. P.
Published: February 2015

The inverse operator technique used for the treatment of magnetic field influence on transport processes in polyatomic gases is extended to the case where the spherical approximation for the relaxation coefficient of [W]p [J]q polarizations cannot be used. The general procedure is outlined and subsequently illustrated for the magnetic field influence on the heat conductivity.
The Formation of Molecules in Three Atom Collisions using the Eikonal Approximation
Authors: Czuchaj E.
Published: February 2015

A new approach to the calculation of a teratomic recombination rate constant k(T) has been dem-onstrated. An expression for k(T) has been obtained in the eikonal approximation. The numerical calculation has been carried out for the Rb*-Xe system. Good agreement in the order of magnitude between the present results and the experimental data of Carrington et al. has been obtained.
Polar Solvent Structure in the Debye-Hückel Theory of Strong Electrolytes
Authors: Holub K. , Kornyshev A. A.
Published: February 2015

A general formula is derived for the potential energy of an ion in an ionic solution using all assumptions of the Debye-Hückel theory except the assumption of constant permittivity. For the solvent the spatial correlation of polarization fluctuations is taken into account. The potential energy of an ion in it's ionic atmosphere is calculated for different models of the spatial correlation of polarization fluctuations and the corresponding excess free energy and activity coefficient of an ion is evaluated. It is concluded that the Debye-Hückel theory using a constant value of e should only be valid for electrolyte concentrations lower than 10-7 mol · dm-3 . The paper intends to show the consequences of dropping the assumption of constant permittivity and so encourage further efforts towards a more exact treatment of the problem.
Ultrasound Absorption in Mixtures of Phenol with Carbontetrachloride and Cyclohexane
Authors: Mang H. , Kohler Friedrich
Published: February 2015

Ultrasound absorption has been measured in binary mixtures of phenol with carbontetrachloride and cyclohexane covering the complete concentration range at 20, 30, 40, and 50 °C. Absorption maxima in dilute phenolic solutions are interpreted as arising from cyclic association of phenol to trimers or tetramers.
Ion Formation in Field Desorption of Salts
Authors: Röllgen F. W. , Giessmann U. , Heinen H. J.
Published: February 2015

It is shown that field emission of cations from adsorption layers of salts results from an ionic conductivity of the salt layers.
Anharmonic Force Field and Isotopic Relations of Ozone
Authors: Hennig P. , Strey G.
Published: February 2015

The anharmonic force constants of ozone up to fourth order have been determined from recently published spectroscopic data of 16O3 and 18O3. For the first time all experimental data presently available have been used in a least squares fit. Compared with recent work, the correct formula for the Darling-Dennison resonance parameter γ has been used now. The nonuniqueness of the solution is discussed. In addition, isotopic rules for various spectroscopic parameters are derived.
Photoleitung in 2,3-Dimethylnaphthalin bei gepulster Lichteinstrahlung / Transient Photocurrents in 2,3-Dimethylnaphthalene Single Crystals
Authors: Falter W.-W.
Published: February 2015

Hole currents are observed by illuminating 2,3 DN single crystals with 347 nm and 337 nm. The probability of generating free holes is a function of temperature and electric field-strength. In the cleavage plane of the crystals the mobility does not depend on the direction of the applied field and amounts to 2.6·10-1 cm2/Vsec at room temperature, which exceeds the related value measured perpendicularly to the plane by a factor of four. The temperature-dependence of the mobility indicates shallow hole-trapping exspecially close to the surface. The trap depth is estimated to be 10-2 eV. Temperature also influences the pulse shape, by which one can conclude that hole traps of 0.2 eV and ≲ 0.1 eV exist in a thin surface layer. Photocurrents exited with 347 nm increase stronger than quadratically with the electric field. Deep hole traps, being also restricted to the surface region of the crystals, are made responsible for this fact.
Temperaturabhängigkeit des kernmagnetischen Relaxationsverhaltens von Wasserprotonen in nativer Stärke / The Temperatur Behaviour of the Transverse Relaxation of the Protons of Water Molecules in Native Starch
Authors: Hennig H.-J. , Lechert H.
Published: February 2015

Measurements of the temperature behaviour of the transverse relaxation of the protons of water molecules in native potatoe starch show two sorption states and an exchange of protons between these states. From model calculations of Woessner and Zimmermann the occupation of the states and the exchange rate can be evaluated. The portion of more tightly bound water molecules comes out to be about 17%. The energy of activation of the exchange decreases with increasing water content and lies with values in the range of 26 to 31 kJ/mol distinctly below the values observed usually for proton-exchange processes in similar systems.
Elastische und thermoelastische Konstanten von Y3Fe5O12-, Nd3Ga5O12-und Sm3Ga5O12-Granaten / Elastic and Thermoelastic Constants of Y3Fe5O12-, Nd3Ga5O12-und Sm3Ga5O12-garnets
Authors: Haussühl S. , Mateika D. , Tolksdorf W.
Published: February 2015

Elastic and thermoelastic constants of cubic Y3Fe5O12-, Nd3Ga5O12-, and Sm3Ga5O12-garnets are measured hy ultra-sonic methods. The small differences of the elastic properties within the group of gallium garnets are nearly quantitatively described by the r−4 -rule, thus indicating the dominant role of ionic bonds. These garnets exhibit a similar thermoelastic behaviour. A slight but significant depression of the elastic constants is observed in Y3Fe5O12.
Sharp Resonances in Radiationless Transitions
Authors: Howard W. E. , Schlag E. W.
Published: February 2015

We have observed extremely sharp Doppler-free resonances in the measurement of molecular lifetimes of ex-cited states in the low pressure gas-phase of naphthalene. These resonances are seen at extremely low magnetic fields and have a width of only 3 Gauss. Their extreme sharpness of 2.8 × 10−4 cm−1 is within a factor of 2 of the natural width of the radiationless transition, and some 130 fold below the Doppler width of the state considered. Such sharp resonances should provide unique insights into the states and dynamics of radiationless processes. They are probably due to sharp field dependent changes in the non-radiative coupling strength of the spin-orbit transition into the triplet.
Phase Diagrams of Binary Mixtures of Phenylenediamines and Dihydroxybenzenes
Authors: Dhillon M. S.
Published: February 2015

Solid - liquid equilibria for o-phenylenediamine + resorcinol, m-phenylenediamine + pyrocatechol, + resorcinol and p-phenylenediamine + pyrocatechol, + resorcinol have been studied by the thaw-melt method. The types and melting temperatures of the complexes formed in theses mixtures were ascertained from the phase diagrams.
Promptes und verzögertes Spektrum des reinen Dibenzofuran-Kristalls / Prompt and, Delayed Spectrum of the Pure Dibenzofuran-crystal
Authors: Hoffmann K. D. , Schmillen A. , Wolff H.
Published: February 2015

Prompt and, Delayed Spectrum of the Pure Dibenzofuran-crystal The mirror symmetry of the prompt emission and the transmission spectrum allows to estimate the S1→S0 O-O transition to be at 32.64 · 103 cm-1.

The correspondence of the prompt emission spectrum of the DBF-crystal with the spectra of the solutions of DBF in bencene and methyl-alcohol as well as measurements of the delayed spectrum indicate a high purity of the crystal.

Decay-time measurements of the delayed fluorescence and the delayed spectrum as a function of intensity of excitation light demonstrate the long wave emission in the delayed to be the phosphorescence of DBF.
A Practical Method to Derive Canonical Transformations in a Closed Form and it’s Application to an Antiresonant Electron-Phonon-System
Authors: Sigmund E.
Published: February 2015

A practical method for the calculation of canonical exponential transformations in closed analytic forms is presented. An application to an antiresonant electron-phonon system is given. In particular the optical zero phonon line is calculated, which reflects the resonant nature of the system
Hyperfeinstruktur des RbBr / Hyperfine Structure of RbBr
Authors: Tiemann E. , Hölzer B. , Hoeft J.
Published: February 2015

The rotational transition J=2 → 3 of RbBr at 8.4 GHz was measured. The analysis of the hyperfine structure resulted in the quadrupole coupling constants of the isotopic species 85Rb79Br, 85Rb81Br, 87Rb79Br, and 87Rb81Br in the ground vibrational state. From the observation of 85Rb79Br in the excited vibrational states υ = 1 and 2 the vibrational dependence of the quadrupole coupling constants was derived:

e qυ Q(85Rb) = (-47.20 + 0.28(υ+1/2) ±0.25) MHz;

e qυ Q(79Br) = (3.08 + 0.75 (υ+1/2) ±0.30) MHz
Hydrogen Bond Studies
Authors: Berglund Bo , Tegenfeldt Jörgen
Published: February 2015

The quadrupole splittings in the deuterium NMR spectrum from single crystals of deuterated sodium Perchlorate monohydrate, NaClO4-D2O, have been measured at 25 °C and - 55 °C. At room temperature, the 180° flip frequency of the D2O molecules is large compared to the difference between the splittings for the two deuterons. The average quadrupole coupling constant (e2 q Q/h) and asymmetry parameter η are 134.1(4) kHz and 0.621(5), respectively. At -55 °C, the electric field gradient tensors for each of the two deuterons were observed corresponding to slowly flipping water molecules, and e2 qQ/h and η for the two deuterons are 231.5(6) and 226.7(6) kHz and 0.196(4) and 0.195(5), respectively. The results indicate that the hydrogen positions in NaClO4-H2O are dynamically disordered
An ESR Investigation of Illuminated Polycrystalline TiO,
Authors: Dyrek Chr. , Schindler R. N.
Published: February 2015

Formation of paramagnetic centers in polycrystalline TiO2 samples and changes thereof upon heat treatment, addition of oxygen, and illumination, respectively, are described. From the tem­perature dependence of the disappearance of a photoprodueed Ti3+ signal with g= 1.96 an apparent activation energy of ~ kcal/mole is estimated for the electron annihilation processes.
Laufzeitmessungen in Fluoren-Einkristallen / Transit Time Measurements in Fluorene Single Crystals
Authors: Eckhardt H.
Published: February 2015

The hole drift mobility in single crystals of fluorene was determined by transit time measurements. At room temperature the mobility along the c-axis is (0,82 ± 0,14) cm2/Vs and in the abplane (0,72 ± 0,1) cm2/Vs. In the temperature ranges 200K<T<300K and 165K<T<300K μc and μab have been found to be ~T-1,5 and ~T-1,0, respectively. In both cases the mobility reaches a constant value for low temperatures (100 K). In the range 300 K<T<345 K μ decreases very strongly with increasing temperature {μ~T-5). Traps, especially deep and shallow surface traps, influence the pulse heighth and the pulse shape. From the change of the pulse shape with temperature a trap depth EH = 0,4 eV for shallow traps is determined.
Stark Effect Investigations in the 5d 6s (3D) 6p 2D3/2-State of Li I
Authors: Eckert H.-J. , Koch H. , Zimmermann P.
Published: February 2015

The Stark effect of the 5d 6s (3D) 6p 2D3/2-state of Lu I was investigated using the level crossing technique in combined magnetic and electric fields. From the broadening of the Hanle signal due to the shifts of the crossings in the electric field the Stark effect parameter |β| - 6(2) kHz/(kV/cm)2 was deduced. A theoretical study considering some of the mixing states is made.
The Partial Structure Factor of Sulphur in Liquid CS2 by Combining X -ray and Neutron Diffraction Results
Authors: Orton B. R.
Published: February 2015

The partial structure factor for sulphur in liquid CS2 at 20 °C has been computed by combining published x-ray and neutron diffraction results. Assuming that there are no correlations of molecular orientations, it is found that the main peak height of this sulphur-sulphur partial structure factor is smaller than that for carbon-carbon. This result is discussed in relation to the solid state structure and recent theoretical calculations.
Propagation and Absorption of Electromagnetic Waves in a Coaxial Plasma-Waveguide-System (m=1)
Authors: Kampmann B.
Published: February 2015

The dispersion relation of electromagnetic waves propagating in a coaxial plasma-waveguide-system is solved for a cold plasma. The influence of losses, discharge tube, and radial gradients of electron density are discussed in detail. Strong absorption is found near the dipole resonance of the plasma column.
Soret Coefficient of Liquified Simple Gases at Low Temperatures: the Kr-CH4 System
Authors: Longreé D. , Legros J. C. , Thomaes G.
Published: February 2015

The Soret coefficient for the krypton-methane system at 107.5 K has been measured. The results are compared with the thermodynamic theory of Prigogine, with a Rice Allnatt calculation, and with the Enskog theory for dense hard spheres gases.
Cherenkov Losses of a Relativistic Neutron in a Conducting Medium*
Authors: Sastry G. P. , Parida B. K.
Published: February 2015

Expressions are derived for the combined Cherenkov and Ohmic losses of a relativistic magnetic dipole moving in a (1) strongly and (2) weakly conducting medium
A Molecular Dynamics Study of Aqueous Solutions. VII. Improved Simulation and Comparison with X-Ray Investigations of a NaCl Solution
Authors: Pálinkás G. , Riede W. O. , Heinzinger K.
Published: February 2015

The molecular dynamics simulation has been improved by introducing the Ewald summation for ion-ion interactions. On the basis of the Pauling radii new Lennard-Jones parameters have been derived for the halide ions. The results of a simulation of a system consisting of 200 water molecules, 8 sodium and 8 chloride ions are compared with x-ray investigations of a 2 molal NaCl solution through the structure functions. The first neighbor model commonly used in the x-ray analysis of multicomponent liquids is fitted to the experimental structure function and to the structure function calculated from the radial pair correlation functions of the simulation. The parameters of the two fits and the radial pair correlation functions calculated from the fitted first neighbor model are compared. On the basis of this comparison the usefulness and the limitations of the first neighbor model are discussed
Effects of Ion Motion on Hydrogen Stark Profiles
Authors: Seidel Joachim
Published: February 2015

The influence of ion motion on Stark broadened hydrogen lines is studied using the Method of Model Microfields which allows a uniform unified treatment of electrons and ions. Contrary to former theoretical investigations, strong effects are found in the line centres of L-α, H-α, and H-β which agree well with recent experimental findings, especially those of Wiese, Kelleher, and Helbig.
Nahordnung von Mg-Cd-Legierungen beim Übergang fest flüssig / Short Range Order of Mg-Cd-alloys during the Transition from the Solid to the Molten State
Authors: Boos A. , Steeb S.
Published: February 2015

Recently1 a method was published for the determination of short range order parameters in binary melts and also a method for the determination of the concentration of different structures which form such a melt.

These methods are used in the present work to evaluate the atomic structure of Mg-Cd-melts and to reveal the changes in short range order during the melting process.
Chlorine Compounds in the Stratosphere: HOCl, HOOCl, and ClOO
Authors: Warneck Peter
Published: February 2015

Possible reactions leading to the formation and the loss of HOCl and HOOCl in the stratosphere are explored. Since such reactions must be exothermic, the heats of formation of the title com­pounds are discussed first. Values adopted are ΔHf
0(HOCl) = -22 ±3, ΔHf
0(ClOO) = 20.5 ± 0.4, ΔHf
0(HOOCl) = -17 kcal/mol. Several important reactions are then identified. The most significant reactions apepar to be

HO2 + CIO → HOCl + O2

HOCl + hν → OH + Cl < 400nm

OH + ClO + M → HOOCl + M

HO2 + ClOO → OH + ClO.

From estimates of the associated rate coefficients and photodissociation factors the steady state concentrations of HOCl and HOOCl are derived. Both are sufficiently low to exclude a significant influence upon the steady state concentrations of CIO and Cl.
123Te and 125Te Fourier Transform NMR Investigations
Authors: Buckler K. U. , Kronenbitter J. , Lutz  , Nollle A.
Published: February 2015

The NMR signals of 123Te and 125Te have been observed in solutions of K2TeO3 and Na2TeO3 in D2O. In these solutions the ratios of Larmor frequencies ν(125Te)/ν(123Te), ν(125Te)/v(2H) and ν(125Te)/ν(23Na) have been determined with high accuracy. With the measured chemical shifts of 2H, 23Na, 125Te relative to infinitely diluted solutions the ratios of the Larmor frequencies are extrapolated and values of the magnetic moments are given. The relaxation times T1 and T2 are very different for 125Te in TeO3
2-: a ratio T1/T2 of 8.2 ± 0.4 has been found. No nuclear Overhauser effect due to dipole-dipole interaction of 125Te with the water protons has been detected.
Notizen: Monte-Carlo Simulation of a Two-dimensional Dipolar Lattice
Authors: Romano S.
Published: February 2015

Monte-Carlo calculations were carried out on a system consisting of 256 point-dipoles, whose centres are fixed in a two-dimensional square lattice with the usual boundary con­dition; the Epstein-Ewald-Kornfeld algorithm was used in evaluating the electrostatic energy. No evidence of a first-order phase transition was found, and the results suggest there might be a second-order one. Additional calculations were carrierd out using the mean-field theory, which was found to overestimate the transition temperature by about a factor two.
Self-Diffusion of Tl+ in Molten Thalium Nitrate
Authors: Zuca S. , Constantinescu M.
Published: February 2015

The self-diffusion coefficient of Tl+ in molten TlNO3 in a temperature range of about 100° above the melting point was measured by the "diffusion-into-the capillary" method. The obtained results are discussed in terms of ionic interactions occuring in TlNO3 melt.
Angular Forces and Normal Vibrations in Platinum
Authors: Kharoo H. L. , Gupta O. P. , Hemkar M. P.
Published: February 2015

A lattice dynamical study of platinum has been made on the basis of the improved Clark-Gazis-Wallis model considering volume forces of Krebs' nature. The phonon dispersion relations obtained for the three symmetry directions have been compared with the recent inelastic neutron scattering experiments. The specific heat at constant volume has been calculated by Blackman's root sampling technique for temperatures above Θ/10, and below this temperature the calculations are carried out by employing the modified Houston spherical six-term integration procedure. The computed lattice specific heats in terms of the effective Debye temperatures Θ are compared with the available calorimetric data. The theory is in good agreement with the experimental data.
The Structure of Molten Nickel-Phosphorus Alloys
Authors: Waseda Yoshio , Toguri J. M.
Published: February 2015

Detailed analyses of the x-ray scattering intensities of molten nickel-phosphorus alloys ranging from 0 to 30 at.% phosphorus have been carried out. The three partial structures required to characterize the binary alloys have been estimated. The interatomic distance of P -P pairs was found to be about 3.2 Å, and thus phosphorus atoms cannot exist as nearest neighbours in molten Ni-P alloys, at least within the present experimental composition range. It was confirmed that this arrangement of atoms contributed to the characterisic structure in which the expansion of the Ni -Ni distance was unavoidable. Calculations have also been carried out in terms of the dense random-packing model of binary spheres. The calculations were consistent with the experimental results.
Zur Berechnung der chemischen Verschiebung unter besonderer Berücksichtigung des paramagnetischen Terms / Attempts to the Calculation of the Chemical Shift with Especial Consideration of the Paramagnetic Term
Authors: Sterk H. , Suschnigg J. J.
Published: February 2015

Attempts to the Calculation of the Chemical Shift with Especial Consideration of the Paramagnetic Term The calculation of the paramagnetic term according to the Pople formalism of the chemical shift is expanded. The hitherto constant value of the energy gap between the ground state and the excited states is replaced by the value of the lowest lying excitation. This leads to a remarkably better differentiation of the paramagnetic terms of different compounds. The influence is shown on ethane, ethene and ethine.
Zur Anwendbarkeit der Mindo/3-Methode auf die Untersuchung von Grundzustandsreaktionen / Ort the Applicability of the Mindo/3-Method for the Study of Groundstatereactions
Authors: Fleischhauer Jörg
Published: February 2015

An ab inito calculation of the H2-binding-energy is com­ pared with the results of the Mindo/31-Theory with and without configuration interaction to study the applicability of this semiempirical Method for the description of bond-breakening.
Potential Energy Surfaces for Alkali-Trimers
Authors: Mohammad S. Noor
Published: February 2015

Semi-empirical potential energy surfaces for alkali-trimers are derived from the simplest form of London's approximation, by evaluating the Coulomb and exchange integrals as half of the sum and difference of two new interaction potential curves for the 1Σg
+ and 3Σu
+ states of the corresponding alkali dimers. The trimers attain maximum stability in their linear symmetric configuration. The force constants corresponding to stretching and bending deformations of the homonuclear trimers have been calculated for the linear symmetric configuration. Unlike the stretching, the bending deformation is seen to be very much insensitive to the ground state energy variation of the trimers.
Monte Carlo Calculations on Molten Silver Bromide
Authors: Margheritis Chiara , Sinistri Cesare
Published: February 2015

Using crystal data in the range 20-300 °C, the AgBr interionic pair potentials were calculated. By means of these potentials the melt was computer simulated with the Monte Carlo method at three different temperatures (694, 1000 and 1778 K). The system thus obtained is relaxed and it behaves as if an important cohesive force, like the homopolar one, would be lacking.

It was empirically proved that if the interionic repulsive potentials are reduced by about 40% the experimental values of the density and of the internal energy are reproduced.
Effect of Polar States on Superexchange Interaction. Application to Some Dimeric Copper (II) Complexes and to CuCl2 · 2H2O Linear Chain
Authors: Amoretti G.
Published: February 2015

The effect of polar states on the superexchange interaction between two identical spin 1/2 magnetic ions is examined. The one-body potential contributions to the effective exchange constant Jeff are written in terms of the splitting 2Δ0 between the bonding and antibonding single particle lower-states of the dimeric complex. Moreover, the energies of the basis triplet and singlet states are obtained in an approximated form as functions of Δ0 and of two-body molecular integrals. The resulting Jeff, that is the splitting between the lowest singlet and the triplet, differs from that of the pure Heitler-London treatment owing to the ionic contributions to the singlet wavefunction. The theory is applied to some dimeric copper (II) complexes and to CuCl2 · 2H2O linear chain. It is shown that the polar state corrections are generally small, but that they may become important in the case of copper chlorine, where the various contributions to the Heitler-London exchange constant tend to balance each other to give a very small value. Moreover, antiferromagnetic coupling for CuCl2 · 2H2O is accounted for on the basis of a σ-ground state for the single unit, rather than a π one. The conditions to fit the experimental value of Jeff are also discussed.
Ionization, Excitation and Electron Affinity of Naphthalene, Studied with HAM/3
Authors: Åsbrink L. , Fridh C. , Lindholm E.
Published: February 2015

The electronic structure of naphthalene is calculated using the new semiempirical method HAM/3. The calculated photoelectron spectrum is in reasonable agreement with the measured spectrum. The excitation energies are obtained directly in HAM as the difference of the energies of the unoccupied and the occupied orbitals, and the calculated UV spectrum is in good agreement with experiment. The electron affinities are also obtained directly and are also in agreement with recent measurements. The absorption spectrum of the naphthalene anion is in reasonable agreement with experiment also regarding intensities. All calculations did not require more 76 seconds computer time although no advantage was taken of the symmetry of the molecule.
Induktion smektischer Phasen in binären Mischungen nematischer Flüssigkristalle / Induction of Smectic Phases in Binary Mixtures of Nematic Liquid Crystals
Authors: Heppke G. , Richter E.-J.
Published: February 2015

Binary mixtures of 4-n-alkyl- and 4-w-alkyloxy-4′-cyanobiphenyls with homologous 4,4′-di-n-alkyloxy-azoxybenzenes exhibit the induction of a smectic phase. From some of the phase diagram it can be concluded that the induced smectic phases (ISP) are of the SA type, and this is probably true for all mixtures studied. The thermal stability of the induced smectic phases can not be correlated with the clearing temperatures of the single components, but a dependence on their ability to form smectic phases is very likely. It is postulated that mixtures of terminal polar and terminal non polar nematic liquid crystals are generally able to exhibit the induction of smectic phases.
Determination of Ionic Mobilities of Uranium in n-Propanol and n-Butanol at 25 °C
Authors: Marx G. , Nitsche H.
Published: February 2015

In the system UO2(NO3)2 · 6H2O/n-Propanol the limiting ionic conductance of (1/2UO2
2+) was found to be 12.31 cm2 Ω-1 mol-1 at 25 °C, its association constant being 3.6 · 109 l2 mol-2 . The corresponding values in the system UO2(NO3)2 · 2H2O/n-Butanol are:

λ°=23.57 cm2 Ω-1 mol-1 and KA = 1.5 · 1011 l2 mol-2.
Der Tensor des elektrischen Feldgradienten am Cl-Atom des Äthylchlorids aus mikrowellenspektroskopischen Messungen / The Tensor of the Electric Field Gradient at the Cl-Nucleus of Äthylchlorid from Microwave Spectroscopic Measurements
Authors: Braun Walter
Published: February 2015

From microwave spectra of the molecules CH3CH2
35Cl, CD3CH2
35Cl, CH3CD2
35Cl, CD3CD2
35Cl, CD2HCD2
35Cl-sy, CH2DCH2
35Cl-sy the field gradient tensor at the Cl-nucleus was determined. The investigation results in an asymmetry parameter of 0.015 and a small deviation between the field gradient axis and the C-Cl-bond axis of 0.7°. The complete field gradient tensor in the principal axis system was determined for the molecules CD2HCD2
35Cl-asy, CH2DCH2
35Cl-asy and CH3CHD35Cl.
The Microwave Spectrum of Disilylsulfide
Authors: Dössel K.-F. , Sutter D. H.
Published: February 2015

We report an analysis of the rotational spectrum of (SiH3)2S, leading to the rotational constants A, B, C and the internal rotation parameters V3, θ and Iα.
Calibration of the Spectral Radiance of a Low Current Carbon Arc between 185 nm and 340 nm
Authors: Einfeld D. , Stuck D.
Published: February 2015

The spectral radiance Lλ of a low current carbon arc (current 7.3 amps, voltage 65 V) has been calibrated in the spectral range from the air cut-off (λ ≈ 185 nm) to 340 nm with an uncertainty of ± 3% utilizing the electron synchrotron radiation of DESY, Hamburg. In the wavelength range above 260 nm these values differ by less than ± 6% from the measurements of Magdeburg and Schurer.
Absorption and Fluorescence Spectra of some 1,3,4-Oxadiazole Derivatives in n-Paraffins at 77 K
Authors: Bałuk P. , Kawski A.
Published: February 2015

The quasilinear absorption and fluorescence spectra of 2- (1-naphthyl) -5-phenyl 1,3,4 oxadiazole, 2-(2-naphthyl)-5- phenyl 1,3,4 oxadiazole, 2-(1-naphthyl) -5-(4-biphenylyl) - 1,3,4 oxadiazole and 2-(2-naphthyl)-5-(4-biphenylyl)-1,3,4 oxadiazole have been studied in n-hexane, decane and nonane at 77 K. An analysis of the vibrational structure in the first electronic excited singlet state (S1) and in the ground state (S0) is given. Internal oscillations in the investigated molecules found from the quasilinear spectra are in agreement with those found in the infrared spectra.
On the Green-To-Red Line Intensity Ratio in the Solar Corona
Authors: Mital H. P. , Narain U.
Published: February 2015

Green-to-red line intensity ratios have been investigated by including various processes, like radiative recombination via bound levels, autoionization, dielectronic recombination, etc. An improvement in the value of coronal temperature is found.
1,2,4-Triazole Complexes, IV
Authors: Engelfriet D. W. , Groeneveld W. L.
Published: February 2015

Magnetic susceptibility measurements on single crystals of Mn(II)(trz)2(NCS)2 in the temperature range 1.8 - 300 K are reported. The compound has two-dimensional structural and magnetic properties. The data from susceptibility measurements are accounted for by considering the material to be a quadratic-layer, S = 5/2 Heisenberg antiferromagnet. From the comparison of the data with predictions from series expansions the intralayer exchange constant was found to be J/k = -0.25 K. A transition to the antiferromagnetic state is observed at TN = 3.29 K with the b axis being the preferred axis. Magnetization measurements at 1.8 K along the b axis reveal a spin-flop transition at 10.8 kOe. The occurence of a second discontinuity in the magnetization curve at 15.6 kOe is explained by assuming that the spin system goes to the spin-flop state via an intermediate spin arrangement, as is suggested by the presence of tilted MnN6 octahedra. From pulsed-field magnetization measurements at 1.17 K, a saturation field Hc = 74 kOe is found which also leads to J / k = -0.25 K. With the aid of neutron powder diffraction at 1.2 K the magnetic space group was determined to be Apb′a 2′! Preliminary results from heat capacity measurements on the corresponding Fe(II), Co(II), Ni(II) and Cu(II) compounds are reported.
Theoretische Untersuchungen an einem Elektronenstrahlerzeuger mit Spitzenkathode / Theoretical Investigation of an Electron Gun with a Point Cathode
Authors: Rauh H. , Kern D.
Published: February 2015

Electron-optical properties of a gun with a point cathode are determined numerically by tracing a greater number of electron trajectories. In order to calculate the beam current density distribution, an attempt was made to describe the properties of the gun in terms of the parameters describing the initial conditions of the trajectories. Contrary to the conventional electron-optical imaging theory, the electron gun under consideration cannot be sufficiently characterized by a few aberration coefficients, since only a small fraction of the trajectories forming the electron beam would be covered by an expansion containing linear, third and fifth order terms, so that the series expansion method is not applicable.
On the Physical Dynamics of Laser Mode Sweeping in a Fabry-Perot Resonator of Varying Optical Length
Authors: Bodem F.
Published: February 2015

We present in this paper a basic analysis of the physical mechanism underlying the internal frequency modulation of a laser oscillator which is caused by a variation of the optical path length of its Fabry-Perot resonator. It is shown how adiabatic variations of the optical resonator length are continuously converted into frequency variations of the electromagnetic field energy trapped between the resonator mirrors by a rapid succession of small Doppler shifts, thus complying with the general principle of adiabatic invariance in oscillatory systems.