bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Correlated Basis Function Method and its Application to Liquid 3He, Nuclear Matter and Neutron Matter
Authors: Nitsch J. 
Published: February 2015

Abstract
The method of correlated basis functions is studied and applied to the Fermi systems: liquid 3 He, nuclear matter and neutron matter. The reduced cluster integrals xijkl... and so the sub-normalization integrals Iijkl... are generalized to coinciding quantum numbers out of the set {i, j, k, I,...}. This generalization has an important consequence for the radial distribution function g (r) (and then for the liquid structure function) ; g(r) has no contributions of the order O (A-1). For 3 He the state-independent two-body correlation function g(r) is calculated from the Euler-Lagrange equation (in the limit of r → 0) for the unrenormalized two-body energy functional. For nuclear matter and neutron matter we adopt the three-parameter correlation function of Bäckman et al. Then the energy expectation values are calculated by including up to the three-body terms in the unrenormalized and renormalized version of the correlated basis functions method. The experimental ground-state energy and density of liquid s He can be well reproduced by the present method with the Lennard-Jones-(6 -12) potential. The same method is applied to the nuclear matter and neutron matter calculations with the OMY-potential. The results of the energy expectation values indicate a practical superiority of the unrenormalized cluster expansion method over the renormalized one.
Microwave Diagnostics of a Strong Arc Discharge Plasma in SF6
Authors: Musil J. , Žáček F. 
Published: February 2015

Abstract
The paper deals with the microwave free-space diagnostics of high collision arc discharge plasmas. It is found that information about the electron density N and the collision frequency ν in such a plasma can be obtained from the energy transmitted through the plasma by an electromagnetic wave. The phase of the electromagnetic wave cannot be used since it is almost the same as that of a wave passing through vacuum. These basic concepts are verified experimentally at a frequency of 37.5 GHz.
It is shown how the time dependence of the electron density in a plasma with constant and with time variable collision frequency may be evaluated.
Direkte Bestimmung der Geschwindigkeitskonstanten des Durchtritts vom kleinen zum großen Hohlraumsystem im Molekularsieb Typ 13 X für Sr-und Ba-Ionen / Direct Determination of the Rate Constants for the Sr- and Ba-exchange Between the Small and Large Channels in LMS 13 X
Authors: Frohnecke K. , Fischbach H. 
Published: February 2015

Abstract
Direct Determination of the Rate Constants for the Sr-and Ba-exchange Between the Small and Large Channels in LMS 13X The rate constants for the intracristalline Sr-and Ba-exchange between the small and large diameter channels of LMS 13X were measured. For this matter the method of interrupting the ion exchange was modified. It is assumed, that a first order reaction takes place. Using the rate constants and the diffusion coefficients, which were measured by Hoinkis and Levi, the total exchange of Sr 2+ and Ba 2+ could be calculated.
Die Sekundärelektronen-Ausbeute verschiedener Materialien bei Beschuß mit leichten Ionen hoher Energie / Secondary Electron Yield from Various Materials under the Impact of Light Ions at High Energies
Authors: Beck H. P. , Langkau R. 
Published: February 2015

Abstract
The backward emission of secondary electrons from thick targets of graphite, aluminum, copper, molybdenum and tantalum under the impact of protons, deuterons, 3 He-ions and a-particles has been measured for incident energies in the MeV-range. The data are discussed within the scope of theoretical considerations based on low-energy studies taking into account the contribution due to ;< 5-rays.
Das Rotationsspektrum des IBr / Rotational Spectrum of IBr
Authors: Tiemann E. , Möller Th. 
Published: February 2015

Abstract
The microwave spectrum of IBr was measured in the low rotational transition J = 3 ← 2 in order to resolve the hyperfine structure as completely as possible. Rotational constants and quadrupole coupling constants were derived for both nuclei. The observation of the rotational spectrum in different vibrational states yields the vibrational dependence of the rotational constants as well as of the hyperfine parameters. The Dunham potential coefficients a0, a1, a2, a3 are given.
UV Absorption Spectra of Methyl, Cyclopropyl Ketones
Authors: Al-Khafaji Jabria A. , Shanshal Muthana 
Published: February 2015

Abstract
The UV absorption spectra of some 1, alkyl, cyclopropyl, methyl ketones are recorded in different solvents. For the 1, methyl, cyclopropyl, methyl ketone (3) a Δ - π* band is observed in organic solvents. The spectra are discussed in terms of a second order perturbation of both Walsh and MO′s of cyclopropane and the carbonyl group. It is found that the hypsodiromic shift of the n-π* band in the cyclopropyl ketones is due to a destabilization of the π* MO. The appearance of a Δ - π* in (3) is due to a rotation of the carbonyl group from the bisected conformation and a stabilization of the π* MO.
On the Lattice Parameters of the Orthorhombic Low Temperature Phase of Crystalline Acetylene-d2
Authors: Koski Harri K. 
Published: February 2015

Abstract
Acetylene-d2, C2D2 , is known to exist in two crystal structures. The neutron powder diffraction data of the orthorhombic phase for temperatures between 4.2 K and 148.7 K have been analyzed and the refined lattice parameters and the calculated unit cell volume tabulated. By expressing the observations as functions of the vibrational energy, values for the Debye characteristic temperature and the static lattice and zero-point quantities are calculated with the method of least squares. Theoretical values for the coefficient of thermal expansion, quantities proportional to the isothermal compressibility, and the calculated density of solid C2D2 are given. The average frequencies associated with the characteristic temperatures for the lattice vibrations along the a-and b-axes are calculated. Finally, an estimate for the latent heat of the cubic-orthorhombic transition is obtained from the Clausius-Clapeyron equation.
Die Excimerenkinetik des 3,4-Benzo[a]pyrens / Excimer Formation Kinetics of 3,4 Benzo[a]pyrene
Authors: Hafner F. , Frey R. , Hauser M. , Heidt G. 
Published: February 2015

Abstract
The photophysical and kinetic constants are completely determined by photostationary and time-dependent fluorescence measurements. Deviations from the usual reaction scheme at higher concen-trations are caused by a quenching process of the excimer by the unexcited monomer. This diabatic process which is not observed with pyrene and naphthalene takes place in spite of the short excimer lifetime. A possible correlation between internal conversion and diabatic reactivity is discussed.
EMF Measurements on the Thermocell Ag(T1)/AgI/Ag(T2)
Authors: Shahi K. , Chandra S. 
Published: February 2015

Abstract
Thermal emf measurements have been carried out on AgI using reversible silver electrodes be-tween 75° and 300 °C. A sharp change in the magnitude of the thermoelectric power (Θ) has been observed at 146 °C corresponding to the β to a phase transition. The results may be represented by the equations
β-AgI: θ =- [(0.351 ±0.032) (103/T)+0.203 ± 0.083]mV/K, 70-146 °C,
a-AgI: θ =- [(0.052 ± 0.011) (103/T)+0.531 ± 0.031]mV/K, 146-300 °C.
From these the heats of transport of the Ag+ interstitials and ions respectively in the two phases have been calculated to be (0.351-h/2), h being the heat of formation of a Frenkel defect pair in β-AgI, and 0.052 eV, whereas the activation energies for conduction are 0.38 and 0.051 eV respectively. These results are compared with those of previous authors.
Notizen: Diffusion im flüssigen System Chlorbenzol + Brombenzol / Diffusion in the Liquid System Chlorobenzene + Bromobenzene
Authors: Haase R. , Kottmann R. , Dücker K.-H. 
Published: February 2015

Abstract
Results of measurements of the diffusion coefficient D for the ideal liquid system chlorobenzene+bromobenzene are presented. They cover the whole composition range at 295 K (≈ 22 °C). Within experimental accuracy, D is a linear function of the mole fractions. The product D η (η: viscosity) is a more complicated function of composition.
Notizen: Specific Volume Studies on Some Nematic Liquid Crystals
Authors: Bahadur Birendra 
Published: February 2015

Abstract
The temperature variation of the specific volume of two nematic liquid crystals (HBT and OBT) has been observed in both the nematic and isotropic regions. A sudden jump is observed in the vicinity of the nematic-isotropic transition indicating a first order phase transition. Pretransitional effects are found to occur only on the nematic side of the transition. This accords with the Maier-Saupe theory. Some parameters such as SK , A, the adiabatic compressibility, the Rao number, and the van der Waals constant are also determined.
Zur Theorie des stimulierten Raman-Effektes an Kristallen/ Theory of Stimulated Raman Effect in Cyrstals
Authors: Borstel G. , Merten L. , Rath K. 
Published: February 2015

Abstract
The theory of stimulated Raman effect in biaxial and uniaxial crystals is presented on the basis of a parametric process. For the system consisting of Stokes wave and polariton wave a dispersion relation is derived which allows to predict the threshold value of the stimulated process and the gain factor for real crystals.
Theory of the Polarized Fluorescence Experiment
Authors: Frehland Eckart 
Published: February 2015

Abstract
The static polarized fluorescence experiment is investigated for the most general case of arbitrary orientation distributions of transition moments in the fluorescent sample and arbitrary rearrangements of transition moments during the excited fluorescent state. It is shown that all available information is contained in a tensor of fourth order. The maximum number of independent components of this tensor is 36. Hence in the general case 36 polarized intensities must be measured in order to utilize the maximum available information. For special symmetries of orientation distributions this number is drastically reduced. In the case of vanishing rearrangement it is 15, for planar arrays (axial symmetry) not exceeding 11 and for spherical symmetry only 2. The results may be extended to the time-dependent polarized fluorescence experiment.
Study on the Ionic Bombardment in a Glow Discharge Lamp
Authors: Blum F. , Büger P. A. , Murphy R. J. 
Published: February 2015

Abstract
The surface of copper alloys was studied by means of a scanning electron microscope after having been sputtered by a glow discharge source under typical conditions for spectrochemical analysis. The surface topography developed during the process of sputtering gave the following two results: It would appear that the energy spread of the bombarding ions is small and the variation in the angles of incidence of these ions is less than usually accepted.
Vibration-Rotation Interaction in the Microwave Spectrum of KOH
Authors: Kuijpers P. , Törring T. , Dymanus A. 
Published: February 2015

Abstract
The fine structure of the microwave transition J=6←5 of 39KOH and 41KOH has been studied. The analysis results in improved vibration-rotation interaction constants, a1 , a2, y22, yll and ql. It is shown that coupling between the bending and stretching vibrational modes contributes to the observed frequencies.
Protonenspin-Relaxation durch Spinrotationswechselwirkung in kristallinen Methylnaphthalinen/Proton Spin-Lattice Relaxation on Crystalline Methylnaphthalenes by Spin-Rotational Interaction
Authors: Schütz J. U. von 
Published: February 2015

Abstract
The high temperature behavior of the longitudinal proton spin relaxation time T1 of several methyl naphthalene crystals, differing in the arrangement and number of the substituted CH3-groups, was investigated in a large magnetic field range. It could be prooved - for the first time via proton spin relaxation - that in solids the fast reorientation of CH3-groups with low hindering barriers can lead to remarkable contributions to the total relaxation rate by spin-rotational interaction, in addition to the well known dipolar interaction discussed in preceeding works.
Bandstruktur der linearen Polyacene
Authors: Tyutyulkov N. N. , Polansky O. E. , Fabian J. 
Published: February 2015

Abstract
For infinite polyacenes the energy gap (ΔE∞) is given by ΔE =

, where Δcorr is a factor determined by the electronic correlation and Δgeom is a molecular geometry dependent factor. We find in the selected case Δcorr>Δgeom .The energy gap values calculated with this formula are in good agreement with the values calculated from the spectroscopic data of polyacenes (0.8-0.9 eV).
Many-Body-Systems and Exciton Model in New-Tamm-Dancoff- Formulation
Authors: Wahl F. 
Published: February 2015

The NTD-method is a procedure to compute differences of eigenvalues in quantum mechanical problems: ωαβ=λα-λβ.
It is an instruction to transform and truncate an infinite linear system of eigenvalue equations ω τk=

Ak
m τm which is derived with the aid of fundamental field equations or corresponding
Hamilton-operators, as e.g. with Heisenberg's nonlinear spinor equation. In this paper we want to test the NTD-method for a many-body-model in solid state physics. We elaborate on the physical and mathematical aspects by choosing a suitable transformation τ → φ = C τ to get a new linear 1 system ω φk=

Bkk+2iφk+2i which permits a truncation to evaluate approximation of states. The efficiency of this method is demonstrated by treating a two-body-system in presence of polarisation quanta, known as exciton model
Ion Chemistry of Phosphirane and Structure of the Phosphirane Molecular Ion
Authors: Profous Zdenek-Christian , Wanczek Karl-Peter , Hartmann Hermann 
Published: February 2015

The mass spectrum and the ion molecule reactions of phosphirane and of mixtures of phosphirane with NH3 , NH2D, NHD2 and ND3 have been studied by ion cyclotron resonance spectrometry. Almost all important product ions are formed by PH-group transfer reactions, where ethene is generated as the neutral particle. Only two of the more abundant ions, the protonated molecule, H2P(CH2)2
+ and the ion m/e=63, P2H+, are formed via other reaction pathways. Secondary, tertiary and quarternary product ions with the general formula R(PH)n
+ (R: phosphirane fragment, n-1, 2, 3) have been detected.
The molecular ion is proved to have a cyclic structure. Two possible structures of the product ions with two and three phosphorus atoms are discussed: a structure with an open phosphorus chain, leaving the phosphirane ring intact and a ring extended structure, produced by a ring extension reaction of the PH-group.
Several rate constants of the ion molecule reactions of the phosphirane molecular ion are given
Valence and Core Electron Spectra of Mg in MgO in Evoporated Thin Films
Authors: Haider N. C. , Alonso J. , Swartz W. E. 
Published: February 2015

X-ray photoelectron spectra (XPS) are obtained for Mg in MgO using high quality (purity 99.999%) Mg films prepared and oxidized under pressures of 10-6 ~ 10-8 torr and measured on an ESCA-36 spectrometer at a pressure of 10-8 torr. AlKα line source was used for excitation, and the minimum of Au valence band at 5.0 eV was chosen for calibration.
With increased oxidation the valence band shifts about 1.0 eV towards the Fermi level, but with extreme contamination it disappears completely. Accurate measurements of binding energies have been made of Mg in pure Mg, and Mg in MgO. The average shift resulting from oxidation is 1.1 eV for Mg(2s) and 1.5 eV for Mg(2p) core levels. It is also observed that the contamination effect due to oxygen decreases with increasing film thickness. The present results are compared with the previous results, and a new interpretation is offered by postulating the formation of two kinds of oxides, stoichiometric and chemisorbed layers in Mg on oxidation
Hyperbolic Motion in the Finite-size Model of the Radiating Electron
Authors: Sorg M. 
Published: February 2015

Abstract
Within the framework of the finite-size model of the electron recently dovelopped the case of hyperbolic motion is studied rigorously by means of an exact solution. The energy-momentum balance is discussed as well as the critical phenomena arising if the external field strength comes into the range of order of the maximal self-field strength of the particle. It is found that the commonly accepted Lorentz-Dirac-Rohrlich theory is only a good approximation for small values of the external field strength.
The Behaviour of Populations in a Rapidly Expanding Plasma Flow
Authors: Nishida Michio 
Published: February 2015

Abstract
The distributions of populations of helium atoms in a source flow expansion were calculated for the two different conditions Te = 7500K, Ne = 1014cm-3 and Te = 5000 K, Ne = 1013cm-3. The populations in the levels higher than n = 20 were taken to be in locally thermal equilibrium with the electrons. The steady state consideration was applied to the populations of the levels from n = 7 to n = 19. For the levels lower than n=6 the expansion flow term was included. The results show that the calculated population densities of the lower levels deviate greatly from those estimated from the steady state consideration.
Applicability of the Uniformly Expanding Universe Model to Laser Produced Plasmas
Authors: Lengyel L. , Salvat M. 
Published: February 2015

Abstract
The similarity model commonly used in laser plasma calculations is shown to be identical with the uniformly expanding universe model analysed by Heckmann1. A solution is found to the corresponding gasdynamic equations also for the case of nonvanishing entropy production. The solution is analytic for a class of heat input rates. Heat input is shown to affect the gas motion in an exponential manner. The limitations on the applicability of this model to laser plasma compression and expansion calculations are discussed.
Adiabatische Korrektur der Born-Oppenheimer-Näherung beim PbS/Adiabatic Correction of the Born-Oppenheimer Approximation of PbS
Authors: Tiemann E. , Stieda W. U. , Törring T. , Hoeft J. 
Published: February 2015

Abstract
The rotational microwave spectrum of PbS was measured in a frequency range from 65 to 105 GHz in order to determine the higher order isotopic effect of the rotational constant. From this we deduce (by calculating the nonadiabatic and the Dunham-correction) the adiabatic correction of the Born-Oppenheimer approximation, which depends linearly on the reciprocals of the masses of the two atoms in a diatomic molecule. Because of the small mass variation by isotopic substitution for the heavier molecules of the IV/VI-compounds the relative accuracy of the primary measurements must be of the order of 10-6 . The least square fit of 112 rotational transitions yields a relative error of 10-7 for the rotational constant Y01 . The adiabatic corrections from Pb and S differ by a factor of 50, which was unexpected.
Röntgenbeugungsuntersuchung an geschmolzenem Selen und Tellur sowie an Legierungen des Systems Selen—Tellur/ X-ray Diffraction Study of Molten Selenium, and Tellurium and of Molten Selenium — Tellurium-Alloys
Authors: Hoyer W. , Thomas E. , Wobst M. 
Published: February 2015

Abstract
At temperatures just above the melting point molten Selenium seems to be a mixture of long chains and eight-membered rings. With increasing temperature the number of rings and the average chain length decrease. At 460 °C the average chain length lies in the range of 10 atoms.
In a slightly supercooled Tellurium-melt the number of first neighbours is two. The atoms are arranged in chains. Selenium rich Se-Te-alloy-melts are built up of mixed chains. It seems to be possible, that a smaller part of atoms forms Se6Te2 rings. At Tellurium concentrations higher than approximately 50 at.-% the chainlike structure with two next nearest neighbours changes to a disturbed Arsen-like short range order. The number of electrons in the first coordination shell, the short range order parameter introduced by Cowley and the partial coordination numbers show that Se-Te-alloys are of the "solution system" type, but in the whole concentration range for each atom there is a tendency to have "strange coordination".
An X-ray Optical Method for the Determination of Diffusion Properties in Very Thin Bimetallic Films
Authors: Wagendristel A. 
Published: February 2015

Abstract
The change of x-ray optical properties during diffusional alloy formation can be used for the evaluation of diffusion parameters in bimetallic thin film couples. The most pronounced phenomenon governed by these properties are the known Kiessig interferences which can be observed in the specular scattered x-ray beam at very small glancing angles. From these interference patterns diffusion data can be obtained by a comparison with calculated reflection curves based on a proper model for diffusion.
The most useful thickness range for this method is below 1000 Å, where common x-ray techniques lose their applicability. Since the changes in the interference patterns are most significant in the early diffusion stages, this technique is most suitable for observing initial interdiffusion, which very often occurs with enhanced diffusion rates.
The experimental check of the method is performed in the Au-Ag system. Bimetallic films of the pure components were annealed at temperatures between 200 and 300 °C. In this temperature range diffusion parameters from 10-16 to 10-14 cm2/s were found in good agreement with values obtained by other techniques.
Double Dielectric Relaxation of Non-Confocal Membrane-Covered Ellipsoidal Particle Suspensions
Authors: Ichimura Hideo , Feinstein David , Schwartz Richard F. 
Published: February 2015

Abstract
The complex dielectric constant of suspensions of membrane-covered ellipsoidal particles is formulated in terms of the complex dielectric constant of the interior, the membrane and the medium, the volume ratios p and q, and the shape factors n1 and n2. It is not necessary for the two ellipsoidal interfaces (one between the interior and the membrane, the other between the membrane and the medium) to be confocal, nor for the thickness of the membrane to be uniform. The result is factorized to demonstrate double relaxation.
In addition, the blurring mechanism of multiple relaxation is naively explained.
A New Method for Surface Ionization of Organic Molecules by Attachment of Alkali Ions in Moderate Electric Fields
Authors: Röllgen F. W. , Schulten H.-R. 
Published: February 2015

Abstract
It is shown that polar organic molecules may be ionized at metal surfaces by attachment of alkali ions in moderate electric fields. Lithium salts adsorbed on tungsten surfaces were employed for this method of ionization. The alkali ion attachment results from a surface reaction in the transition region between a thermal and field ionization. The particular advantage of this ionization method lies in the production of very simple mass spectra which contain no decomposition products of ions.
Molekularstruktur und Fluoreszenz aus ππ*-angeregten Zuständen organischer Moleküle/ Molecular Structure and Fluorescence from ππ* Excited States of Organic Molecules
Authors: Fratev Filip 
Published: February 2015

Abstract
Molecular The classification of the types of excited molecular structures suggested in a preceding paper1, can be used for interpretation and prediction of fluorescence ability of large classes of conjugated organic molecules. Possible electronic conditions for S2- and dual fluorescence are discussed. An extension of Kasha's rule is suggested.