bluuebunny/crossref_metadata_2025_split huggingface dataset:
Verbesserung des Meß-und Auswerteverfahrens zur Bestimmung der gemeinsamen und partiellen Diffusionskoeffizienten am Beispiel von Kupfer-Gold-Legierungen/An Improved Method for Measuring and Analysing Chemical and Intrinsic Diffusion Coefficients Applied to Copper-Gold Alloys
Authors: Heumann Th. , Rottwinkel Th. 
Published: February 2015

Abstract
A method is described which enables the determination of the chemical diffusion coefficients D̃ in a binary system as well as the intrinsic diffusion coefficients of both components with sufficient accuracy. The difference in concentration between the diffusion couples should not exceed 5 at%. Numerous diffusion profiles at different annealing times are taken by electron microprobe analysis from each specimen before calculating D̃ according to a method proposed by Sauer and Freise Combining the results for different pairs of specimens with overlapping concentration range mean values of D̃ are obtained in the total concentration range unter consideration. An analytical expression for D̃ is given, which is used to determine the diffusion profile for a special diffusion couple according to the method of Wagner4 . By this one obtains the total diffusion profile including the flat ends which cannot be accurately determinated by electron microprobe analysis. The determination of the intrinsic diffusion coefficients according to van Loo5 is based on these calculated profiles with additional knowledge of the position of the welding interface. This method has been applied to diffusion measurements in Cu-Au alloys. The following relation for D̃ has been found in the concentration range between 0 and 32 at% Au at 911 °C
D̃(N)Cu Au
911 °C =3,71·10-10 + 5.04·10-9 N+1.76·10-10 N2 + 1.01 -10-11 N3 [cm2 sec-1 ]. N = mole fraction of Au.
Erzeugung von freien Defektelektronen in 2,3 Dimethylnaphthalin- Einkristallen mit schwach absorbiertem Licht/ Photo generation of Holes in 2,3-Dimethylnaphthalene by Weakly Absorbed Light
Authors: Falter W.-W. 
Published: February 2015

Abstract
Irradiation of 2,3 DN single crystals by 5 nsec light pulses from a nitrogen laser (337 nm) and by 20 nsec light pulses from a Q-switched ruby laser (347 nm, second harmonic) respectively, causes generation of free holes. Centers which are most probably associated with crystal defects are electronically excited by the incident light directly or by energy transfer from the primary excited 2,3 DN. The excited centers are quenched by charge transfer interaction with 2,3 DN. Mobile holes are separated from the localized negatively charged centers subject to the applied electric field. The centers are distributed uniformly over most of the volume, but in a region closer than 1 μm to the surface the concentration increases rapidly. In this surface layer also a high density of hole traps are found to exist, which are responsible for the temperature dependent rise of the photocurrent pulses below room temperature. At high current densities recombination between ionized centers and drifting holes becomes important. The recombination coefficient is found to be 10-5 cm3 /sec. Analysation of the fast (60 nsec) rise of the photocurrent pulses above room temperature gives information about the lifetime of the excited centers and about the lifetime of the singlet excitons in the surface layer. Values of ≈ 30 nsec for the centers and ≲ 10 nsec for the excitons are found. The volume lifetime of the singlet excitons is measured to be 80 nsec.
Energieübertragung in Anthracen dotierten 2,3 Dimethyl- naphthalin-Einkristallen im Temperaturbereich 4K < T < 300 K / Energy Transfer in Anthracene Doped 2,3 Dimethylnaphthalene Single Crystals
Authors: Ganz P. 
Published: February 2015

The fluorescence spectra and the decay time of emission bands of pure and anthracene doped 2,3 Dimethylnaphthalin single crystals excited by short light pulses were examined for temperatures of 4 to 300 K.
On raising the temperature from 40 to 120 K the decay time and the relative quantum yield of 2,3 DN decreases, the emission is shifted by about 150 cm-1 to higher energies and simultanously the energy transfer to the anthracene impurity molecule increases.
A model calculation is presented which allows a theoretical interpretation of the experimental results
Mößbauer-spektroskopische Untersuchungen am System Fe1+xSb mit NiAs-Struktur/ Mössbauer-spectroscopy in the system Fe1+xSb with NiAs-structure
Authors: Richter F. W. , Schmidt K. 
Published: February 2015

Measurements in the system Fe1+xSb for 0.13 ≦ x ≦ 0.30 and in the temperature range 10 K ≦ T ≦ 625 K are represented.
In the paramagnetic phase one observes a small quadrupole splitting of ΔνQ=0.272 (8) mm/s, independent of the non-stoechiometric portion x. From the temperature dependence of the isomeric shift δ a Debye-temperature θ= (766 ± 100) K was determined.
Néel temperatures are found to be about 211 K, varying smoothly with x, according to an increased number of bipyramidal FeII-atoms and therefore a stronger influence of the ferromagnetic coupling with octaedral FeI-atoms.
The measured Mössbauer spectra in the antiferromagnetically ordered phase can only be interpreted as a superposition of several magnetic line-sextets, probably due to a variation of the local magnetic field at the site of 57Fe, with different numbers of nearest Fe-atoms. An exact assignment of the analysed fields to the number of nearest Fe-atoms was not possible.
The magnetic saturation fields are in between 95 kG and 155 kG increasing with x. The direction of the local fields are found to be parallel to the plane (001) of the NiAs-lattice.
Ein Verfahren zur Untersuchung von Phasenumwandlungen flüssiger Kristalle durch elektrische Leitfähigkeitsmessungen/ Investigation of Phase Transitions in Liquid Crystals by Means of Electrical Conductivity Measurements
Authors: Heppke G. , Schneider F. 
Published: February 2015

Abstract
A procedure for determining the transition temperatures of liquid crystals is described which is based on observation of the electrical conductivity as a function of temperature. It is found in particular that plotting the function d lg x/dT against the temperature gives a resolution and a sensitivity comparable to that of thermal methods of analysis (DTA and DSC). Dynamic orientation effects of the liquid crystals in the sample cell which usually lead to an increase in sensitivity are discussed. The phase diagram of the system 4,4ʹ-di-n-pentyloxy-azoxybenzene/4,4ʹ-di-n-heptyloxy-azoxybenzene determined using the electrical conductivity method is presented.
Graph Theory in Chemistry II. Graph-Theoretical Description of Heteroconjugated Molecules
Authors: Graovac A. , Polansky O. E. , Trinajstić N. , Tyutyulkov N. 
Published: February 2015

Abstract
The Sachs' formula which relates the structure of a (vertex-and edge) -weighted graph and its characteristic polynomial is given. Weighted graphs are used to represent conjugated molecules containing the variety of heteroatoms and heterobonds. Vertices and edges in such molecular graphs have different weights following the deviation of the corresponding (Hiickel) Coulomb and resonance integrals from the standard (benzene) values.
Notizen: Low Temperature Magnetic Susceptibility of Sm2(WO4)3
Authors: Lal H.B. , Dar Naseeb 
Published: February 2015

Abstract
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

Abstract
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.
Korngrößenabhängigkeit der Ummagnetisierungsvorgänge im Reineisen
Authors: Deimel P. , Röde B. , Wislaug R. 
Published: February 2015

Abstract
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

Abstract
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

Abstract
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°.
The Problem of Runaway Solutions in the Lorentz-Dirac Theory
Authors: Sorg M. 
Published: February 2015

Abstract
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

Abstract
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.
Time Reversal Behaviour and Reciprocity Theorem of Transport-Relaxation-Equations
Authors: Waldmann L. 
Published: February 2015

Abstract
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).
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Phase Diagrams of Binary Mixtures of Phenylenediamines and Dihydroxybenzenes
Authors: Dhillon M. S. 
Published: February 2015

Abstract
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

Abstract
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.
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