bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theory of Optical Band Shape for A1g —T1u Transition. II
Authors: Nasu Keiichiro 
Published: February 2015

Abstract
A theory of the optical band shape for A1g - T1u transitions is developed based on the method of the characteristic function. It covers the region of weak coupling between the electrons and the phonon modes of a1g , eg and t2g symmetries, and takes account of the phonon dispersion. It is bound that the cumulant function of the characteristic function can be described by a two-time phonon correlation function which includes the multi-phonon correlation due to the Jahn-Teller effect. A Dyson equation of the phonon correlation function is solved under specific conditions where the contribution from the eg modes is neglected and the phonons have a Lorentzian dispersion. Analytical expressions are given for intensity, peak shift and broadening of a few lower phonon side bands, and it is found that the one phonon side band of the t2g mode shifts to higher frequencies than that of the a1g mode.
Notizen: Redetermination of the Dissociation Energy of Europium Monoxide and Its Bearing on Atmospheric Release Experiments
Authors: Hildenbrand D. L. , Murad Edmond 
Published: February 2015

Abstract
The dissociation energy, D0
0, of EuO has been redetermined and found to be 4.80 + 0.11 eV. This value is substantially lower than previous data indicated. The results of recent atmospheric release of europium metal are discussed in light of this finding.
Messungen der Knight-shift in flüssigen Cu-Ga-Legierungen mit Mn-Verunreinigungen/Knight-Shift in Liquid Cu-Ga Alloys with Mn Impurities
Authors: Zollner R. , Sotier S. , Holzhey Ch. , Lüscher E. 
Published: February 2015

Abstract
In a series of liquid Cu-Ga alloys, the 63Cu and 71Ga Knight-shift K was measured in a high temperature NMR-Spectrometer from 400 to 1200 °C. Alloying the Cu-Ga host with 2% Mn causes a strong change in K which comes mainly from nuclei in the nearest neighborhood (l.n.n.) of Mn. This gives a first estimate of the conduction electron spin polarisation close to Mn. The data are compared to previous results in the Cu-Al-Mn system.
Comment on the Analysis of Microwave Rotational Zeeman Effect Spectra of Symmetric Top Molecules
Authors: Engelbrecht L. , Sutter D.H. 
Published: February 2015

Abstract
It is pointed out that the translational Lorentz effect which has been neglected in all previous analysis of rotational Zeeman spectra has considerable effects on the overall appearance of the Zeeman multiplets if the rotational transitions show first order Stark effect. This situation occurs for symmetric tops and for E-species transitions of molecules with low barrier internal rotations. Inclusion of the translational Lorentz effect leads to corrections to the published g‖-values of symmetric tops which are far outside the quoted experimental uncertainties. As an example numerical results are given for CH3F and CH3CCH.
Die Übertragung der LCAO-Interpolationsmethode auf Gitterelektronen im Magnetfeld / The LCAO Interpolation Method Applied to Crystal Electrons in a Magnetic Field
Authors: Müller H. G. 
Published: February 2015

The splitting of the energy levels of crystal electrons in homogeneous magnetic fields of moderate strength is described in terms of the matrix elements of the LCAO method. The matrix elements are regarded as adjustable parameters connected with the energy structure of the crystal electron without magnetic field. The translational symmetry of the crystal in a magnetic field is exactly taken into account, and the matrix elements contain the symmetry of the point group of the material.
The resulting eigenvalue equation is a system of linear difference equations. In analogy to the treatment of a similar one-dimensional difference equation for the differential equation of Mathieu type the eigenvalues result from an investigation of a vector recursion formula. In connection with this method the limiting cases magnetic field and crystal potential approaching zero are discussed in short
Phase Transitions in the Alkali C1 —n. C4 Alkanoates
Authors: Ferloni P. , Sanesi M. , Franzosini P. 
Published: February 2015

The enthalpies and entropies of fusion and of solid state transitions in Li formate and acetate; Li, Na, K, Rb, Cs propionates; Li, Rb, Cs n.butyrates were determined by differential scanning calorimetry. Supplementary information was provided through conductance measurements on solids. The collected data, together with those from previous papers, allowed to give a picture of the thermal behaviour of the alkali C1-n. C4 alkanoates.
Heat capacity data on solid and molten Na formate, acetate and propionate were also determined
Particles and Antiparticles According to Covariant Schrödinger Equations
Authors: Bopp Fritz 
Published: February 2015

Abstract
We introduce manifestly covariant Schrödinger equations. This has the advantage that the energies of particles are always positive. Charges of particles and antiparticles have opposite signs. The physical vacuum equals the formal one. - All that occurs because manifestly covariant Schrödinger equations yield pairs of operators which differ only in some signs of eigenvalues: (i) The number of particles and the charge, (ii) the space-time wave vector and the space time momenta, (iii) the kinematical and the dynamical angular momenta.
Shock Compression of Plane Targets by Laser Ablation
Authors: Kessel C. G. M. van 
Published: February 2015

Abstract
The properties of laser ablation driven shockwaves in plane transparent targets are investigated using high speed photography. The pressure, density and temperature of the compressed state behind the shockwave is determined with the shockwave Hugoniots of the target materials. The shockwave propagation is explained by a modified blastwave model and the energy transfer to the shock compressed region is estimated.
Reflexionserscheinungen bei Torsions-Alfvén-Wellen in inhomogenen Magnetfeldern/ Reflection Phenomena of Torsional Alfvén Waves in Inhomogeneous Magnetic Fields
Authors: Räuchle E. , Schüller P. G. 
Published: February 2015

Abstract
The propagation of torsional Alfen waves in a cylindrical plasma is investigated. Superimposed on the plasma are various types of spatially inhomogeneous axisymmetric magnetic fields. Characteristic examples are: in the direction of propagation spatially decreasing, increasing and periodically modulated magnetic fields. The wave lengths are of the same order of magnitude as the characteristic lengths of the inhomogeneities. Strong reflection is observed which depends on wave frequency and strength of the field inhomogeneity. There exists good agreement between experimental results and numerical calculations.
Wellenabsorption in einem Plasma mit zwei Ionensorten/ Wave Absorption in a Plasma with Two Ion Species
Authors: Schlüter H. , Schürger G. 
Published: February 2015

Abstract
A theoretical study is carried out for the resistive loading of an rf power source inductively coupled to a plasma cylinder which is immersed in a magnetic field. The plasma is assumed to consist of electrons, two ion and two neutral species. The results are compared with measurements in a hydrogen plasma.
Energieübertragung zwischen gleich-und ungleichartigen Molekülen in Lösung III. Experimente über Fluoreszenzlöschung durch absorbierende Fremdstoffe/ Energy Transfer Among Like and Unlike Molecules in Solution III. Study of Fluorescence Quenching by Foreign Absorbing Substances
Authors: Kawski A. , Stoń M. 
Published: February 2015

Abstract
Energy Transfer Among Like and Unlike Molecules in Solution 111. Study of Fluorescence Quenching by Foreign Absorbing Substances Radiationless energy transfer between unlike molecules (heterotransfer) in fluid solutions was studied by the quenching of fluorescence by foreign absorbing substances. The quenching of electronic excitation energy of 2-aminopurine and 2-aminopyrimidine, acting as sensitizers, and by acridine or 9-methylanthracene, acting as acceptors, was investigated in ethanol and compared with the theory of "multi-shell model" of a luminescent centre. In fluid solutions the critical distance for energy transfer is little depended on the diffusion. Good agreement was found with the equation taking into account only the excitation energy migration.
X-ray Diffraction Study of Molten Te and Tl-Te Alloys
Authors: Waseda Y. , Tamaki S. 
Published: February 2015

Abstract
X-ray diffraction patterns have been obtained from molten Te at 470, 520 and 570 °C. The heights of the peak maxima in the structure factor were much the same in contrast with those of typical molten metals such as sodium.
Molten Tl-Te alloys have been studied by X-ray diffraction for the alloy compositions 25, 33.3, 50, 60 and 75 at% Te at 500 °C and at about 20 °C above the liquidus. The total structure factors for the 25 and 33.3 at% Te alloys were almost the same as that of pure Tl. This implies that the atomic arrangement of these molten alloys is very close to that of pure Tl. Although a drastic change is not found in the general form of the structure factor, the parameter of the range of local atomic order abruptly increases on passing from Tl2Te to more Te-rich alloys. The three partial structures were also evaluated from the observed X-ray intensities assuming that each partial structure is independent of the relative abundance of the constituent elements in the alloys.
The Dependence of the Oxygen Isotope Fractionation in the Hydration Water of CuSO4 · 5 H2O on the Crystallization Temperature
Authors: Götz D. , Heinzinger K. , Klemm A. 
Published: February 2015

Abstract
The fractionation of the oxygen isotopes in the water collected by stepwise dehydration of CuSO4·5H2O has been measured for the crystallization temperatures 25, 40 and 50 °C. From X-ray and neutron diffraction studies it is known that three different kinds of water, differing in their binding in the crystal, exist in CuSO4 · 5 H2O. On the basis of the results reported here it is concluded that isotopic equilibrium exists between the different kinds of water in the crystal and the mother liquor during the crystallization process. In addition it is shown that on stepwise dehydration the water molecules from the different types of sites can be separated. Consequently, the measurements provide the possibility to determine crystallization temperatures from intracrystalline oxygen isotope fractionation alone. Possible applications in isotope geothermometry are discussed.
Bloch-Wave Analysis in Electron Diffraction Experiments with a CaF2 Single-Crystal Wedge
Authors: Ishida K. , Johnson A. W. S. , Lehmpfuhl G. 
Published: February 2015

Abstract
The fine-structure spots in an electron diffraction pattern from a crystal wedge represent the strong partial waves of strongly excited Bloch waves. Diffraction experiments near the [100] and the [110] zone axes of a CaF2 crystal were carried out in order to determine from a fine-structure profile analysis the low-indexed structure potentials V111, V200 and V220 the absorption coefficients of different Bloch waves. Under these experimental conditions there exist three strong Bloch waves; one is concentrated at the rows of Ca atoms, another along the rows of F atoms and a third is concentrated in the space between the atom rows. The absorption coefficients depend in a characteristic way on the density of atoms along the atom rows. This density is different for the two projections leading to different absorption coefficients. A strong background due to inelastic scattering was observed mainly in one strong reflection which was supposed to be due to phonon excitation.
Double Resonance Modulation as a Standard Technique in Microwave Spectroscopy II. Line Shape and Integrated Intensity
Authors: Stiefvater Otto L. 
Published: February 2015

Abstract
It is shown that there occur two easily distinguishable line shapes in DRM spectroscopy. These reflect the change of the integrated intensity of the signal transition when pump radiation is applied. They readily permit deductions concerning the position of the shared energy level. This result is useful for the analysis of complicated spectra, as is illustrated with examples.
An expression is derived which permits the determination of the integrated intensity of absorption lines by DRM techniques alone. It does not require knowledge of the absolute value of the pump power and provides, therefore, a convenient basis for relative intensity measurements without recurrence to Stark effect modulation.
Notizen: Atomic Ordering in Superconducting Nb3Al
Authors: Hechler K. , Volk P. 
Published: February 2015

Abstract
Samples of Nb3Al produced by a melting process in an arc furnace show a pronounced increase in Tc by annealing them at 750 °C for 48 hours. This behaviour is accompanied by a small decrease in the lattice constant and an increase in the long-range order parameter. These two effects are thought to be responsible for the increase in Tc.
Notizen: A Contribution to the Microwave Spectrum of Dimethylether-D6 in Excited Torsional States
Authors: Lutz H. , Dreizler H. 
Published: February 2015

Abstract
A number of rotational transitions of (CD3)2O in the excited torsional states ν̃=l1 and ν̃=l2 were recorded in the region from 8.0 to 40.0 GHz. The potential parameter V3 and the angle α between the axis of internal rotation and the b-axis were fitted to line splittings. The results are V3 = 2545 cal/mole and α = 60.8°.
Variationsmethode zur Berechnung der Grundzustandsenergie
Authors: Freudenhammer A. 
Published: February 2015

Abstract
Variational Method for Calculations of the Groundstate Energy For Hamiltonians without any symmetry properties, a variational method for the calculation of the groundstate energy is proposed. The numerical computation for the case of the few-electron-problem is based on the evaluation of functional integrals.
Struktur von Aluminium-Indium-Schmelzen mittels Röntgen-Weitwinkelbeugung
Authors: Hoehler Jochen , Steeb Siegfried 
Published: February 2015

Abstract
Structure By transmission of Mo-Kα-radiation, intensity curves were obtained from molten Al and molten In as well as from Al-In alloys containing 10, 20, 30, 40, 70, 80, 90, and 95.3 a/o Al. Radial distribution functions were calculated from these experimental curves. From the RDF's the con-centration dependency of the number NI and the distance rI of nearest neighbours was obtained. The concentration dependency of nearest neighbours reveals the segregation tendency of molten Al-In alloys. The small angle scattering observed in the intensity curves is in agreement with this result and will be treated in a subsequent paper.
Schallgeschwindigkeitsmessung in Al-In-Schmelzen zur Bestimmung der Kompressibilität und der partiellen Strukturfaktoren (s = 0)
Authors: Hoehler Jochen , Steeb Siegfried 
Published: February 2015

Abstract
The adiabatic velocity of ultrasound u in molten AI, In, and Al-In alloys was measured at various concentrations and temperatures. For the alloys the u(T) curves consist of two linear regions with a transition region. The function ⊿u/⊿T and the compressibility versus concentration show positive deviation from linearity. In the latter case the deviation at 1000 °C is smaller than that at 880 °C. The partial structure factors aij(O) were obtained, aAl,Al(0) and aIn,In(0) showing rather high positive, and aAl,In(0) rather high negative values. Thus the segregation tendency becomes obvious. This also can be deduced from the plot of Nń [which is a linear combination of the aij (0) ] versus concentration.
Multi Peak ESCA Bands in Substituted Benzenes and Heterocyclic Compounds
Authors: Pignataro S. , Distefano G. 
Published: February 2015

Abstract
The ESCA spectra of several substituted benzenes and heterocyclic compounds were obtained. Multi peak structures are observed in the various energy regions. The effects are generally interpreted as due to shake up phenomena involving intramolecular charge-transfer transitions between a "donor" and an "acceptor" group in the molecule. A quantitative model for such kind of phenomena is given. It rationalizes the fact that: 1) These shake up processes are, to a large extent, specific to the atoms of the acceptor groups; 2) the shake up energies found for the atoms of the donor part of the molecule (ED) are generally higher than that (EA) observed for the atoms pertaining to the acceptor group; when it is possible to correlate the shake up transitions to an U.V. one, the energy of the ultraviolet absorption transition seems generally intermediate between ED and Ex. The analytical, spectroscopic and chemical importance of multi peak structures of ESCA bands is emphasized. In particular, the fact that it is not generally recognized that the shake up phenomena may cause strong broadening of the bands is criticized in connection with both the evaluation of ionization energies and the deconvolution procedures.
On an Ionic Approximation to Donor-Acceptor and Ion-Molecule Bonding, with Reference to Solvation Effects
Authors: Hooydonk G.van 
Published: February 2015

Abstract
An ionic, i. e. essentially electrostatic, approximation to donor-acceptor bonding between neutral species, ion-molecule interactions and corresponding solvation effects is forwarded. Drago's E-C equation for donor-acceptor reactions and the elimination of solvation procedure (ESP), presented by Drago et al., can consistently by incorporated in the general scheme. The theory yields further correct values for bulk ion-solvation enthalpies of cations H+,Li+,Na+,K+,Rb+ in water with the aid of ionization energies and electron affinities only. The formulae deduced for these types of chemical bonding represent the equivalent of the electronegativity-based theory for the description of ordinary chemical bonding between atoms, introduced earlier.
Slip Effects in Mixtures of Monatomic Gases for General Surface Accommodation
Authors: Lang H. , Müller W. J. C. 
Published: February 2015

Abstract
Macroscopic slip velocity, macroscopic temperature jump, thermal creep velocity and diffusion slip velocity for a mixture of monatomic gases are calculated by using a method developed recently (modified Maxwell-method) for a general gas-gas and gas-surface interaction law, and for a possibly anisotropic surface. The results are expressed in terms of accommodation coefficients of first and second order. Specialization is made for a binary gas mixture. For a comparison the results obtained by Maxwell's original method and general surface accommodation are given. In the case of surface-anisotropy several new slip effects occur.
Miscibility Gaps in Fused Salts
Authors: Margheritis Chiara , Flor Giorgio , Sinistri Cesare 
Published: February 2015

Abstract
An analysis was made of the demixing phenomena in the reciprocal ternaries Li, Me/Br, F (Me = Zn, Pb, Cd). It was found that the system Li, Zn/Br, F shows only a "tendency" to demix; the system Li, Pb/Br, F exhibits a miscibility gap (MG) which could be completely detected in the whole composition square; finally the system Cd, Li/Br, F shows a MG which was only partially measured along the stable diagonal. The trend in demixing of these systems agrees with the values of the standard enthalpy variations of the metathetical reactions.
Kinetics and Mechanism of MAg4I5 Formation in the Solid-State Reactions Between β-Agl and MI (M = K, Rb, NH4)
Authors: Flor Giorgio , Massarotti Vincenzo , Riccardi Riccardo 
Published: February 2015

Abstract
The kinetics of MAg4I5 (M=K, Rb, NH4) formation from β-AgI and MI are investigated on pellets by the contact method. For all the three reactions involved, the governing mechanism is found to be the cation counter-diffusion while the rate-determining step is the diffusion of M+ . On the basis of Wagner's theory the self-diffusion coefficients of K+ , Rb+ and NH4
+ are evaluated in the three compounds.
Viskosität des flüssigen Systems Chlorbenzol + Brombenzol
Authors: Haase R. , Lethen M. , Dücker K.-H. 
Published: February 2015

Abstract
Results of measurements of the viscosity and of the molar volume for the ideal liquid system chlorobenzene + bromo-benzene are presented. They cover the whole composition range between 0 °C and 80 °C. Both the composition and the temperature dependence of the viscosity are discussed.
ENDOR Relaxation Study on Phenyl Substituents
Authors: Plato M. , Biehl R. , Möbius K. , Dinse K. P. 
Published: February 2015

Abstract
The proton ENDOR spectra of various phenyl substituted hydrocarbon radicals in solution show a marked temperature dependence of the positions, widths, and amplitudes of particular lines. These effects are analyzed in terms of three relaxation mechanisms: (i) internal hindered rotation and (ii) torsional oscillations of the phenyl rings, and (iii) molecular tumbling. From the tempera-ture dependence of relaxation effects caused by mechanism (i) hindrance potentials for internal rotation of phenyl rings could be determined. The results are in good agreement with the pre-dictions of simple π-MO theory. Relaxation effects caused by (ii) turned out to be negligible. Mechanism (iii) produces strong variations in linewidths at low temperatures due to the different hyperfine anisotropics depending on nuclear position.
Different Temperature Dependence of Magnetic Susceptibility of Different Molecular Complexes of Copper (II) with 7-Hydroxy-4-methyl-5-aza-hept-4-en-2-on
Authors: Merz L. , Haase W. 
Published: February 2015

Abstract
Two principally different molecular structures in the crystalline state are known from the copper (II) complex with 7-hydroxy-4-methyl-5-aza-hept-4-en-2-on. The magnetic susceptibilities of three forms of this compound [α-(CuEIA)4, β-(CuEIA)4, and β-(CuEIA)4·2 C6H6] have been measured in the temperature range 2.6-300 K. The results indicate that principally different molecular structures correspond to principally different magnetic properties. While the α-form shows antiferromagnetic spin coupling in the S′ = 0 ground state, the electrons in the β-form are coupled ferromagnetically in the S′ = 2 ground state. A fitting procedure of a theoretical equation based on the isotropic HDVV-model led to a satisfactory agreement between calculated and experimental data for α-(CuEIA)4 and β-(CuEIA)4 , while this was not possible for β-(CuEIA)4·2C6H6 . The exchange parameters obtained for α-(CuEIA)4 (g=2.13, J12= -17cm-1, J13=+3.5cm-1, and Na=60-10-8 cgs-emu) are in good agreement with the values given by Ginsberg et al. For β-(CuEIA)4 a weak antiferromagnetic intercluster interaction could be determined at low tempera­tures. The fitting procedure yielded the following values: g=2.05, J12=-6.4 cm-1, J13=+24.2 cm-1, Na=10·10-6 cgs-emu, ⊖=-0.27°.
Geometry of Titration Systems An Application of Horn’s Theory to the Determination of pK-Values
Authors: Willamowski Klaus-Dieter , Rössler Otto E. 
Published: February 2015

Abstract
Following a brief summary of Horn’s theory, the geometry of an n-step titration is presented. This suggests a simple and accurate method for the determination of pK-values from concentration measurements. Mathematically, the affine invariance of barycentric coordinates is exploited. Formal analogies between titration process and kinetics are discussed.
Contribution of the Walsh Orbitals to the Excited States of Conjugated Cyclopropyl Molecules (A PMO Treatment)
Authors: Shanshal Muthana 
Published: February 2015

Abstract
The molecular orbital energies of some conjugated cyclopropyl derivatives are evaluated using 2nd order perturbation. The basis includes the Hückel MOs of the conjugated segment and the Walsh MOs of cyclopropane. The obtained MO sequence is used to discuss the UV absorption spectra of the molecules. It is found that the absorption bands of most of these molecules correspond to Δ-π* or Δ-Δ* excitations and not to π-π* transitions as had been assumed.