bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interpretation of the Structure of LEED Intensity Spectra in τ-Matrix Approximation for the Platinum (100) Surface
Authors: Heinz K. , Lieske N. , Müller K. 
Published: February 2015

Abstract
LEED intensity spectra of the clean (00 and ⅕ 0 beams) and cesium covered (½ 0 beam) Pt(100) surface at normal or nearly normal incidence are compared with a double diffraction approach developed for the scattering process. A second order scattering approach is always restricted to cases where strong attenuation or weak scattering of the propagating electrons can be assumed. The comparison shows that many (but not all) intensity features of Pt(100) can be attributed to first and second order scattering processes only. Some of the maxima are likely to represent resonances. For proper assignment an effective inner potential is chosen that accounts for slowly varying dynamical effects as well as distortions of the crystal. The approach reveals only interpretations rather than predictions. However, it needs nearly no computational effort.
The Proton Distribution in Ice —Ih Investigated by Light Scattering
Authors: Claus R. , Plagge W. , Bilgram J. 
Published: February 2015

Abstract
Oriented single crystalline samples of Ih-ice have been investigated by light scattering. The lade of observable phonon directional dispersion effects shows that ferroelectric domains with dimensions of the order of light wave lengths as stated earlier in the literature, do not exist. The depolarization ratio of the phonons originating from O-H stretching vibrations is found to be independent of the wave vector direction. This demonstrates clearly that the proton distribution is statistical.
109Ag Nuclear Magnetic Resonance Studies of Organic and Inorganic Silver Complexes
Authors: Jucker K. , Sahm W. , Schwenk A. 
Published: February 2015

Abstract
The NMR lines of 109Ag have been investigated in solutions of several silver salts in acetonitrile, propionitrile, pyridine, and ethylenediamine, and also in aqueous solutions of Na2S2O3 and ethyl-amine. In these solvents the Ag+ -ions form one or several complexes. In any case a single NMR line was to be detected, i. e. a rapid chemical exchange between different complexes in a sample may be assumed. The concentration dependence of the chemical shifts was determined with high accuracy for these solutions. From these results the chemical shift data of some defined complexes were derived. The chemical shifts of mixtures of AgCl and AgBr and also of AgCl and Agl dissolved in 70% aqueous solution of ethylamine are linear functions of the anions mole fraction. In two samples of AgNO3 dissolved in organic solvents, the ratio υ(109Ag)/υ(107Ag) = 1.149 640 (1) was measured in good agreement with the value from silver salts in aqueous solutions; i. e. no primary isotopic effect was to be detected within these limits of error (0.9 ppm).
Simple Semiempirical Method of Calculating van der Waals Interactions in Thin Films from Lifshitz Theory
Authors: Vassilieff Chr. St. , Ivanov I. B. 
Published: February 2015

Abstract
The influence of different representations of the dispersion dependence ε (i ξ) on calculating van der Waals interactions from Lifshitz theory is studied. It is shown that with satisfactory accuracy ε (i ξ) can be described by means of Krupp's empirical formula [ε (i ξ) -1]/[ε (i ξ) +1] = a · exp(-b ξ). Making use of that formula a simple expression for the Hamaker function A (h, T) is obtained. Numerical calculations are carried out, the results being compared with those of other authors and with experimental data.
Infrared-Microwave Double Resonance and Double Photon Transitions in FCN
Authors: Jones Harold 
Published: February 2015

Abstract
The utility of a conventional microwave spectrometer in determining the relative disposition of a CO2 -laser line and a molecular transition and ultimately the exact frequency of an infrared transition, is demonstrated by making use of three non-linear spectroscopic effects, high frequency Stark effect, IR-MW double resonance and IR-MW double photon transitions. New situations are encountered in the production of the double photon transitions and the observation of the high frequency Stark effect. From a combination of the double photon transitions with double resonance signals produced in single d. c. Stark components it was concluded that the R (2) transition of the υ1 band of the linear molecule FCN lies 104 ± 15 MHz lower in frequency than the R(20), 9.4 μm CO2 -laser line i.e. R(2) transition = 1079.58711 ± 0.0005 cm-1 .
Calculation of Magnetic Shielding and Susceptibility of H2O and FOH with Gauge Invariant Gaussian Basis Set
Authors: Žaucer Matjaz , Pumpernik Danilo , Hladnik Milan , Ažman Andrej 
Published: February 2015

Abstract
Susceptibility and magnetic shieldings of all nuclei are calculated for water and hypofluorous acid. A finite perturbation SCF method with gauge invariant gaussian basis set is used. Results calculated with a slightly extended basis set agree well with experimental values.
Soret Coefficient and Thermoelectric Power of Thermocells Containing Molten Binary Mixtures
Authors: Haase R. 
Published: February 2015

Abstract
For an ionic melt consisting of two components and of three ion constituents, we derive the interrelation between the Soret coefficient and the initial and final values of the thermoelectric power of a thermocell containing the melt considered. We only use the general formulas of Thermodynamics of Irreversible Processes and there is no restriction with respect to the valency types of the electrolytes.
Bestimmung partieller Diffusionskoeffizienten binären Legierungen vom Substitutionstyp mit Hilfe dünner Scheibenpaare / Determination of the Intrinsic Diffusion-coefficients of Binary Solid Solution Alloys with the Aid of Thin Plates
Authors: Heumann Th. 
Published: February 2015

Abstract
Determination of the Intrinsic Diffusion-coefficients of Binary Solid Solution Alloys with the Aid of Thin Plates A new method for determining intrinsic diffusion-coefficients in binary solid solutions of the substitutional typ is described. For this, thin plates are used having such a thickness that during annealing the specimen becomes nearly homogenious. From the shift of the original interface one obtaines the ratio of the intrinsic diffusion-coefficients for the concentration in the Kirkendall interface.
Excess Volumes of Mixtures of Acetone, Chloroform, Carbon tetrachloride, 1,4-Dioxane and Tetrahydrofuran with o-Dichlorobenzene
Authors: Dhillon M. S. 
Published: February 2015

Abstract
Excess volumes of mixtures of o-dichlorobenzene with acetone, chloroform, carbon tetrachloride, 1,4-dioxane, and tetrahydrofuran have been measured at 293.15 K as a function of composition. The excess volume data have been used to check the one-fluid theory of mixtures with van der Waals's and Guggenheim's equations of state.
Potentiom etrie Studies of the Lithium Interaction with Urea and N-Methylacetamide in Aqueous Solution
Authors: Schäfer O. F. 
Published: February 2015

Abstract
Potentiometrie measurements of the K+ and Li+ activity in the presence of 4M urea or N-methylacetamide have been performed. The results support the view that Li+ associates with amides.
Renormalization Group Approach to a One-Dimensional Cooperative T–e Jahn-Teller System
Authors: Brühl S. , Sigmund E. 
Published: February 2015

Abstract
A linear chain of T-e molecules exhibiting the cooperative Jahn-Teller effect is considered. Following Nauenberg's1 treatment of the one-dimensional Ising model a renormalization group approach is used. The series-expansion of the free energy is put into a closed form.
Bandstruktur von Polymeren mit konjugierten Bindungen II. Bandstruktur der p-Polyphenylea / Band Structure of Polymers with Conjugated Bonds: II. Band Structure of p-Polyphenyls
Authors: Tyutyulkov N. N. , Polansky O. E. 
Published: February 2015

Abstract
It is shown that the energy gap for any arbitrary homonuclear alternant system is given by the expression

where ⊿corr is the correlation correction, and ⊿geom and ⊿top are factors respectively determined by the geometry and the topology of the molecule.
For the infinite p-polyphenyls the correlation correction ⊿corr equals to zero; this means that the width of the energy gap depends only on the topology and geometry of the system.
NOTIZEN: Use of 95Mo NMR for Identification of Molybdenum (VI) Chalcogenide Anions in Aqueous Solution
Authors: Lutz O. , Nolle A. , Kroneck P. 
Published: February 2015

Abstract

95Mo Fourier transform nuclear magnetic resonance studies were made on aqueous solutions of oxo thiomolybdates. Chemical shifts up to 2200 ppm were found for the different unambiguously assigned species MoO4-nSn
2- (n = 0, 1, 2, 3, 4).
Theory of Boundary Conditions for the Boltzmann Equation
Authors: Waldmann L. 
Published: February 2015

Abstract
In preceding papers, Refs. 1,2, boundary conditions were developed for transport-relaxation equations by aid of a general reciprocity postulate for the interface. The same method is now used for the linearized Boltzmann equation. A new scheme emerges: the kinetic boundary conditions consist in a linear functional relation between interfacial "forces and fluxes" - in the sense of non-equilibrium thermodynamics - which are, broadly speaking, given by the sum and the difference of the molecular distribution function and its time-reversed, at the wall. The general properties of the kernels occurring in this atomistic boundary law are studied. The phenomenological surface coefficients of (generalized) linear thermo-hydrodynamics, as e. g. temperature jump, slip coefficients etc., can in a simple way be expressed by the kernel of the atomistic boundary law. This kernel is explicitly worked out for completely thermalizing wall collisions.
P Phase Fluorometer Study of the Excited State Reactions of 4-Methylumbelliferone
Authors: Bauer R. K. , Kowalczyk A. , Balter A. 
Published: February 2015

Abstract
The fluorescence spectra and decay times (the phase differences between the modulated exciting light and the fluorescence) of 4-methylumbelliferone in ethanol-water-acid solutions were investigated. The excited state reaction rates and lifetimes of three forms of the studied dye were evaluated.
X-Ray Attenuation in Silicon and Germanium in the Energy Range 25 to 50 keV
Authors: Gerward L. , Thuesen G. 
Published: February 2015

Abstract
The X-ray attenuation coefficients of silicon and germanium single crystals have been measured using an energy-dispersive method with particular emphasis on the energy range 25 to 50 keV. The experimental results are compared with theoretical calculations of the photoelectric absorption as well as the attenuation due to the Compton scattering and thermal diffuse scattering.
Collisional “Selection Rules” for Asymmetric Top Molecules
Authors: Schrepp W. , Mäder H. , Dreizler H. , Sutter D. 
Published: February 2015

Abstract
Selection rules for collision-induced rotational transitions of asymmetric top molecules are derived by first order perturbation treatment. The theoretical results are in agreement with the results from four-level double resonance experiments in the microwave range.
Optische Kernspin Polarisation (ONP) in Anthracen dotiert mit Phenazin im Temperaturbereich 1,4…300 K / Optical Nuclear Polarisation (ONP) in Anthracene doped with Phenazine in the Temperature Range 1.4…300 K
Authors: Dittrich G. , Stehlik D. , Hausser H. 
Published: February 2015

Abstract
ONP of proton spins in anthracene doped with 1000 ppm phenazine has been measured as a function of the external magnetic field Hp and its orientation with respect to the crystalline axes for the temperatures: 300, 78, 4.2 and 1.4 K. At 300 K characteristic features in magnetic fields up to 150 G are similar to results observed in doped fluorene crystals. They are interpreted as due to ONP as a consequence of level anti-crossing (LAC) in the triplet state of guest-host complexes. The zero-field splitting tensor is: D*= ±0.0101 (2) cm-1, ∣E*∣≲∣ ± 0.000811 cm-1 with the principal axes z* ∥ b, y* and x* in the ac-plane with ∢ (y*, a) =30 + 1°. No complex formation is observed at or below 78 K.
The most prominent feature at all temperatures is the field dependence of ONP when the magnetic field is oriented along the projection of the long molecular in-plane axes of the anthracene molecules. The excitable triplet states in the doped anthracene crystal are discussed in terms of their qualification as ONP-active states.
Synthesis of Fermium and Transfermium Elements Using Calcium-48 Beam
Authors: Gupta Raj K. , Săndulescu Aurel , Greiner Walter 
Published: February 2015

Abstract
The fragmentation theory is used to suggest possible targets to be used with the 48Ca ion beam produced recently at the JINR U-300 heavy-ion cyclotron. Calculations are made for 100 ≦ Z ≦ 116 and are supported by a successful test experiment for the isotope 252102.
Experimental Investigation about the Mechanism of Fission-Fragment Induced Desorption
Authors: Fürstenau N. , Knippelberg W. , Krueger F. R. , Weiß G. , Wien K. 
Published: February 2015

Abstract
The physical processes involved in the fission-fragment induced desorption of molecular and atomic ions from surfaces have been investigated by measuring absolute ion yields, distributions of radial and axial initial energy components and isotopic effects. For this purpose several modifications of the time-of-flight spectrometer were put in practice. By studying multiple ion desorption per fission-fragment correlations between various molecular fragments were identified. The results are compared with predictions of reaction models. The observed phenomena are in agreement with a break-down of the polar-binding potential at the surface caused partially by the low energy electron plasma produced by the fission-fragment.
Population of 3s, 3p, and 3d Sublevels of Atomic Hydrogen after Dissociative Excitation of some Alkanes by Electron Impact
Authors: Hartfuß H. J. , Röll H. 
Published: February 2015

Abstract
The intensity ratios within the Balmer-line Hα have been determined after pulsed electron impact excitation and dissociation of the alkanes CH4, C5H12, C6H14, C7H16, C8H18 and C9H20 . A time resolved technique has been used to separate the line-components by their different life­ times. No contribution of the 3p-level to the intensity of Hα could be detected, as was found earlier in the case of some other hydrogen containing molecules 2, 3. The ratio of the intensity contribution originating in 3s population to the total Ha intensity was found to be between 0.57 and 0.66 de­pending on the target molecule.
Über die Ausbreitung von Stoßwellen elektrischer Drahtexplosionen in Wasser
Authors: Schöfer R. , Seydel U. , Jäger H. 
Published: February 2015

Abstract
Pressure profiles of shod: waves of underwater wire explosions are recorded by means of piezoresistive pressure probes at different distances from the wire. Basing on an expansion of the theory of Brinkley and Kirkwood the time behaviour of characteristic quantities of the shock waves for a large intervall of the travelling distance can be determined by only a few measured values. In this way also statements may be made about the behaviour of the shock wave at those distances at which direct measurements are not possible. Furthermore, conclusions on the conditions for the formation of the shock wave can be made.
Determination of Phase Angles and Absolute Values of the Structure Potential V0002of Cadmium Sulfide from Equal Thickness Fringesin Electron Micrographs
Authors: Ichimiya A. , Uyeda R. 
Published: February 2015

Abstract
Fringe spacings were measured at the three different diffraction conditions: 0002-Bragg position, 0004-Bragg position and the symmetric position for 000l systematic reflections. The absolute value |V0002| and the phase angle Φ0002 were determined by analyzing the ratios of fringe spacings with a 15-beam calculation. The values determined were |V0002| = 6.5 ± 0.5 Volt and tan Φ0002 = -0.54 ± 0.04 on the origin at a cadmium atom. From these values the atom form factors at the position of 0002 reflection were calculated as fx
cd = 42.4 ± 0.5 and fx
s= 13.0 ±0.2, assuming the parameter u determined by X-ray diffraction.
Potentiometrische Messungen an asymmetrischen calciumselektiven Membranelektroden
Authors: Schäfer O. F. 
Published: February 2015

Abstract
Potentiometrie measurements with asymmetric calcium-selective membranes using a three compartment flow-through cell were carried out. These membranes exhibited a behav iour which depended on their orientation with respect to the solutions. Whilst with one orientation of the membranes Nernstian behaviour was observed, in the opposite case con­ siderable asymmetry potentials appeared.
On the Thermal Behaviour of Long-chain Rubidium n. Alkanoates
Authors: Ferloni P. , Zangen M. , Franzosini P. 
Published: February 2015

Abstract
Differential scanning calorimetry allowed to state the main phase relationships in Rb n. alkanoates from octanoate to dodecanoate, and to measure the pertinent heat effects. Before becoming (on heating) a clear melt each homologue can exist as a mesomorphic liquid over a 130 -140 K wide interval. The collected results are compared with those previously obtained for the corresponding Li, Na, K and Cs salts.
Birefringence in the Boundary Layer of a Rarefied Heat Conducting Gas
Authors: Vestner H. , Beenakker J. J. M. 
Published: February 2015

Abstract
In a heat conducting diatomic gas enclosed between parallel plates, the second rank tensor polarization of the rotational angular momenta is non-zero only near the plates. Therefore the gas is birefringent only in a boundary layer which is a few mean free paths thick. The birefringence is calculated with the help of a differential equation and a boundary condition for the tensor polarization. The difference in the index of refraction for light polarized parallel, respectively perpendicular to the temperature gradient is evaluated for the gases N2 and CO with the information obtained from the field effects on viscosity and on thermal conductivity, and from thermomagnetic pressure difference measurements. The effect is estimated to be of measurable size.
Nonlinear Peierls-Boltzmann Equation for Phonons: Structure and Stability of Solutions
Authors: Kaiser Fr. 
Published: February 2015

Abstract
Phonon transport in locally disturbed media is considered. The steady state solutions of the Peierls-Boltzmann type equations are studied. In particular, the flux-dependence of local excitations is investigated. It is proven that for a large class of scattering processes only two types of steady states are possible: a hysteresis type and a threshold one. 4 different types of factorization procedures are applied and it is shown that for these cases the steady states remain nearly unchanged. The stability conditions are reformulated in such a way that one can give a geometrical interpretation. The only stable solutions are nodes. The necessary modification of our model system to allow for limit cycles is indicated. Also, a more complicated situation, where the interaction Hamiltonian HI is a superposition of terms of different order, is investigated. The resulting steady state solution is again a hysteresis.
Electron Den sities from Stark Widths of the HeI 5016 Å and HeI 3889 Å Lines and Helium - Neon Laser Interferometry
Authors: Chiang W. T. , Murphy D. P. , Chen Y. G. , Griem H. R. 
Published: February 2015

Abstract
Measurements of the neutral helium line widths were made in a high pressure electric shock tube plasma of electron density ~ 1 X 10 17cm-3 and temperature ~ 1.5 eV. The measured half-widths are in ~10% agreement with the calculated widths based on GBKO theory. Electron densities were independently determined using a He-Ne laser interferometer. A factor ~ 1.7 discrepancy between measured and calculated Stark widths (or electron densities) reported by Kusch and recently by Einfeld and Sauerbrey could not be confirmed.
Pseudopotential Theory for Atoms and Molecules
Authors: Szasz Levente 
Published: February 2015

Abstract
An exact pseudopotential theory is presented for atoms and molecules with arbitrary number of valence and core electrons and arbitrary number of nuclei. Using the variation method an equation is derived for the best many-valence-electron wave function which is orthogonalized to the core orbitals. Using this equation the exact equation is derived for the many-valence-electron pseudo-wavefunction which does not have to satisfy any orthogonality conditions. The Hamiltonian of the pseudopotential equation is of surprisingly simple structure and does not depend on the energy and/or on the wave function of the valence electrons. It is shown that the simple model Hamiltonian which is used in many pseudopotential calculations can be derived from the exact equation by two plausible approximations. The theory is elucidated on the example of atoms with two valence electrons.
Supercompression of Intense Ion Beams in a Collapsing Pinch
Authors: Winterberg F. 
Published: February 2015

Abstract
Intense ion beams produced in magnetically insulated diodes become fast plasma jets in the drift tube. If a pinch discharge is made over these fast jets they can be magnetically compressed to very small diameters of less than 10-2 cm. Such fast highly focused plasma beams may have important applications for the ignition of thermonuclear microexplosions.
Surface Structure Analysis of Cs/Pt(100) by LEED
Authors: Grandke T. , Heinz K. 
Published: February 2015

Abstract
The intensity spectra of the platinum (100) surface covered with cesium have been analysed by means of a dynamical calculation (RFS) of the diffraction processes using a simplified model of the adsorbate layer. Convergence problems were introduced by the relatively large size of the cesium atoms and the superstructure unit mesh. Yet the agreement between theory and experiment allows to determine a spacing of 4.25 + 0.1 Å between the bulk crystal and the overlayer. According to the model most cesium atoms occupy hollow positions on the topmost (100) bulk layer of platinum. However, there is also a considerable amount of bridge positions giving a mixture of sites, which is responsible for the streaking of special spots observed in experiment.
An Electron-Diffraction Investigation of the Molecular Structure of Toluene
Authors: Iijima Takao 
Published: February 2015

Abstract
The structural parameters of toluene have been deter­ mined by gas-phase electron diffraction. The bond distances in rg are as follows: C-C(ring) 1.399± 0.002 Å, C-C (me­thyl) 1.524± 0.007 Å, C -H(ring) 1.11 ± 0.01 Å. and C-H-(methyl) 1.10 ±0.02 Å.
EPR of VO2+ in ZnCs2(SO4)2 · 6 H2O Single Crystals
Authors: Jain V. K. , Srinivasan T. M. 
Published: February 2015

Abstract
The EPR of VO2+ is studied in single crystals of ZnCs2(SO)4)2 · 6 H2O at X-band. The V-0 axis is found to have two orientations. The spin-Hamiltonian parameters at 298 K are determined.
Dielectric Polarisation of Some Heterocyclic Compounds and Role of π-Electrons in Solution
Authors: Srivastava A. N. 
Published: February 2015

Abstract
The dielectric moments at 35 °C of quinoline, pyridine and isoquinoline dissolved in four non-polar solvents viz. benzene, carbon tetrachloride, cyclohexane and dioxane are found to increase in this sequence in accordance with the molecular structure of these solutes. The surprisingly high moments of quinoline and pyridine in carbon tetrachloride indicate the formation of charge transfer complexes in­ volving the π-electron systems of the solutes.
Die Temperaturabhängigkeit der antiferro- magnetischen Kopplungsenergie in Chromoxid / The Dependency of the Antiferromagnetic Coupling Energy Upon Temperature in Chromium Oxide
Authors: Dräger K. , Gerling R. 
Published: February 2015

For Cr2O3 moderately doped with Ga2O3 it is shown by electronspin resonance that the energy of antiferromagnetic coupling increases by about 20% when the temperature is lowered to the Neel-point Tɴ.
This result indicates the early start of far distance order when still local ordering is to be expected