bluuebunny/crossref_metadata_2025 huggingface dataset:
Theory of Optical Band Shape for A1g —T1u Transition. II
Authors: Nasu Keiichiro
Published: February 2015

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

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.
Notizen: Semiempirical Calculations of the Static Electric Hyperpolarizabilities of Benzene
Authors: Meyer Hermann , Schweig Armin
Published: February 2015

Second hyperpolarizability values of benzene are cal-culated using the “finite perturbation theory” and the CNDO/2, MINDO/1 and MINDO/2 methods.
Steric Inhibition of Resonance in Ortho- substituted Diphenylsulphides Studied by Photo- electron (He I) Spectroscopy
Authors: Colonna F. P. , Distefano G. , Reichenbach G. , Santini S.
Published: February 2015

The analysis of the four lowest ionization energy values related to π MO's in diphenylsulphide and its o-o'-dimethyl and o-o-o'-o'-tetramethyl derivatives indicates that the conformation of the unsubstituted compound largely deviates from planarity, that this deviation increases with ortho-substitution and that the two phenyl rings in the tetramethyl derivative are nearly orthogonal to each other
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

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

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.
Renormalized and Unrenormalized Jastrow Expansions of the Liquid Structure Function for Dense Fermi Liquids
Authors: Nitsch Jürgen
Published: February 2015

We present approximate representations of the liquid structure function S(k) for Fermi systems in the framework of the renormalized and unrenormalized Jastrow theory. Using short range correlations we study the behavior of S(k) in the range of low momenta and compare our numerical results with the experimental data of the liquid structure function of liquid 3He. We conclude that the usual Jastrow ansatz Ψ = Πi<i f(rij)Φ for the trial wave function of a dense Fermi system, together with an application of the cluster expansion method developed by Clark and Westhaus, does not sufficiently describe these systems. Improvements are discussed
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
Untersuchungen zur Quantenausbeute und Stabilität der Verfärbung von UV-empfindlichen Spiropyranschichten, die als Aufzeichnungsmaterial in optischen Datenspeichern verwendet werden / Investigations on the Quantum Yield and Stability of the Coloration of UV-Sensitive Spiropyran Layers Used as a Recording Material for Optical Data Storage
Authors: Vollmer H.-P.
Published: February 2015

A model for the quantum yield of the coloration caused by UV-light in spiropyran layers is described. This model allows to calculate the sensitivity of layers having different compositions. The mechanism concerning the stability of the coloration is essentially clarified. Calculations of the stability for layers of different compositions are possible by a model describing the mechanism approximately
Tensorielle chemische Potentiale — eine notwendige Erweiterung der Gibbs'schen Thermodynamik / Tensorial Chemical Potentials — a Necessary Extension of Gibbs' Thermodynamics
Authors: Stuke B.
Published: February 2015

In a system with a non spherically symmetric pressure tensor, the chemical potential of at least one substance in the system has to be a tensor of the same character as the pressure. The necessary generalization of Gibbs' fundamental equations of thermodynamics is presented. Being already of consequence for equilibrium, this extension is more important for non-equilibrium thermodynamics, in particular for the proper thermodynamic formulation of general relaxation phenomena. Reasons are given why the distinction between dynamic and thermodynamic pressure, originating from the incomplete formulation of customary thermodynamics, is erroneous. Finally a tensorial temperature is introduced which can exist under extreme non-equilibrium conditions, e.g. shock waves
Mikrowellenspektrum und rotationsspektroskopische Konstanten der Methylchlorsilane: CH3SiH2Cl, CH3SiD2Cl und CD3SiD2Cl / Microwave Spectrum and Rotational Spectroscopic Constants of Methyl-chloro-silane: CH3SiH2Cl, CH3SiD2Cl and CD3SiD2Cl
Authors: Zeil W. , Braun W. , Haas B. , Knehr H. , Rückert F. , Dakkouri M.
Published: February 2015

The microwave spectra of the following isotopic species of Methyl-chloro-silane: CH3SiH2Cl, CH3SiD2 and CD3SiD2Cl have been measured and the rotational spectroscopic constants (rotational constants, centrifugal distortion constants and nuclear quadrupole coupling constants) have been determined
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
Vibrational Assignment and Force Constants of Cyclo Octaselenium, Se8, and of the Cyclo Tetraselenium(2+) Cation, Se4
2+
Authors: Steudel Ralf
Published: February 2015

Force constants have been calculated for Se8 (α-monoclinic selenium) after reassigning the literature values of the fundamental frequencies and using a modified Urey-Bradley force field with six force constants. Very good agreement between observed and calculated frequencies was obtained and valence force constants were calculated. A non-linear relationship holds for SeSe stretching force constants and bond distances. Using the Se8 force constants the fundamental frequencies of the square-planar Se4
2+ were calculated and compared with the observed values
A Note Concerning a Recent Comparison of Hydrogen-Like and Hartree-Fock Calculations of the Imaginary Parts of Atomic Scattering Factors for Silicon
Authors: Hildebrandt G. , Stephenson J. D.
Published: February 2015

A comparison is given between hydrogen-like and Hartree-Fock calculated and experimental absorption data for Silicon. Some values omitted in an earlier paper are added
Isotope Effect in the Knight Shift of Potassium
Authors: Sahm W. , Schwenk A.
Published: February 2015

The Knight shifts of the potassium isotopes 39K and 41K were determined with high accuracy: K(39) = 0.2 7 4 35(10)% and K(41) =0.274 93(12)%. The relative isotope effect ΔK/K = -0.210 (20)% is in agreement with the hyperfine structure anomaly 39Δ41
Ab Initio SCF Procedure with Localized Molecular Orbitals of Fragments
Authors: Koller J. , Ažman A.
Published: February 2015

An ab initio procedure is described with a basis set of localized orbitals of the fragments. The method was tested on three molecular systems. The results are in agreement with the results of LCAO calculations
Particles and Antiparticles According to Covariant Schrödinger Equations
Authors: Bopp Fritz
Published: February 2015

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Critical Pitch in Thin Cholesteric Films with Homeotropic Boundaries
Authors: Fischer Fred
Published: February 2015

Calculations of the planar cholesteric texture with homeotropic boundary conditions are presented. At a constant film thickness there is a critical twist t0c below which the planar texture has transformed into a homeotropic one. The additional influence of an external field is discussed for positive and negative anisotropy and with field orientations parallel or normal to the film plane. A general solution of the director field has been found for a normal orientation of the field. A properly adjusted twist t0 obtained by dilution of an optically active material in a nematic matrix opens a possibility to reduce the critical voltage in technical devices.
Rotationsspektrum von BaS
Authors: Tiemann E. , Ryzlewicz Ch. , Törring T.
Published: February 2015

The rotational spectrum of BaS was measured in the frequency range from 55 to 68 GHz, with a heated absorption cell up to 2000 K and a saturation modulation technique. The derived rotational constants and potential coefficients are given.
ENDOR Relaxation Study on Phenyl Substituents
Authors: Plato M. , Biehl R. , Möbius K. , Dinse K. P.
Published: February 2015

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

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

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

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.
Die Trägerdichte von eigenleitendem Silicium/ Carrier Concentration of Intrinsic Silicon
Authors: Wasserrab Th.
Published: February 2015

Since the measurements of Morin and Maita in 1954 it is customary to consider ni = 1.5·1010 cm-3 at T=300K as a standard value of the carrier concentration for intrinsic silicon. Recent measurements and theoretical examinations show a value of ni≈1.0·1010 cm-3 to be more realistic and of higher precision.
ππ and π– p → π0n Scattering in a Multiple-Reggeon-Cut Dual Absorptive Model
Authors: Braun W.
Published: February 2015

A dual absorptive amplitude, in which s-channel resonances are generated by summing up t-channel n-Reggeon cuts, is constructed. Adjusting the two free parameters of the model in the resonance region of π π scattering, the various π π differential high energy cross sections are calculated. The model is also applied to π N charge exchange, where a fit to the high energy data is obtained even without Reggeon-Pomeron cuts
Ion Acoustic Waves in a Density Gradient
Authors: D'Angelo N. , Michelsen P. , Pécseli H. L.
Published: February 2015

A damping-growth transition for ion acoustic waves propagating in a non-uniform plasma (e-folding lengths for the density ln) is observed at wavelengths λc ≈ 2 π ln. The experiment, conducted in a Q-device, supports calculations performed in connection with the problem of solar corona heating
Neuformulierung der von Gibbs begründeten Thermostatik / Reformulation of the Gibbsian Thermostatics
Authors: Ehrsam Christian
Published: February 2015

A generalized state space is introduced with the aim of reformulating the Gibbsian thermostatics. The fundamental criterion of equilibrium is cast in a form specially adapted to simple (multicomponent) systems. A discussion about stable equilibrium states of open systems leads to the familiar stability conditions. The thermodynamic potentials appear within a framework more general than that found in customary presentations; the concept of "generalized availability" is defined
Non-local Generalization of the Lorentz-Dirac Equation and the Problem of Runaway Solutions
Authors: Sorg M.
Published: February 2015

A new, covariant equation of motion for the radiating electron of finite extension is proposed. This new equation excludes the notorious runaway solutions and pre-acceleration
Electrical Properties of Some Divalent Transition Cupferrone Complexes
Authors: Aly H. F. , Abdel-Kerim F. M. , Afifi H. H.
Published: February 2015

From the temperature dependence of the electrical resistivity of the divalent Mn, Co, Ni, Cu and Zn cupferrone complexes it is concluded that these compounds behave as semiconductors. It is also found that the charge transfere (CT) energy as calculated from the UV absorption CT bands is always larger than that drived from the electrical resistivity
On the Thermal Behaviour of Earth-alkali Propionates and n.Butyrates
Authors: Ferloni P. , Sanesi M. , Franzosini P.
Published: February 2015

In a recent paper 1 the results of a calorimetric study on the phase transitions in the alkali C1-n • C4 alkanoates were reported. Continuing the systematic investigation on salts with organic anions, the present work deals with the enthalpies and entropies of fusion (F) and of a few solid state transitions (sstr's) in calcium, strontium and barium propionates and n • butyrates, a salt group for which, as far as we know, thermochemical information is completely lacking in the literature
Angular Momentum and Discrete Symmetries in the Spinor Bethe-Salpeter Equation. II
Authors: Bauhoff W.
Published: February 2015

The classification of states in the fermion-fermion Bethe-Salpeter equation is discussed. They are related to the states in the fermion-antifermion case discussed before. This enables us to obtain restrictions on the interaction in quark models. Some models used in the literature are thereby found to lead to unphysical predictions.
Picosecond Microphotography as a Diagnostic Method for Laser Produced Plasmas
Authors: Ariga S.
Published: February 2015

A single picosecond pulse from a mode-locked dye laser was used for time resolved microphotography of the gasdynamic phenomena occurring in a lasertarget interaction experiment. A time resolution of 5 ps and a spatial resolution of better than 10 μm were experimentally obtained. Results are presented for the case of laser irradiation of a thin foil, shock wave propagation in a transparent target, expansion of the hot plasma and blast wave formation in a background gas.
An Analysis of Nonsimilar Problems on Spherical Blast Waves
Authors: Higashino Fumio
Published: February 2015

An approximate analytical method that is valid for the entire propagation regime of a blast wave is established for point explosions. The method is based on an application of the shock ex-pansion method to boundary conditions. The numerical calculations were carried out for spherical flows with constant adiabatic exponent. The results show that the value of the shock decay coefficient gives good agreement with the numerically exact solution by Goldstine and von Neumann. The profiles of the pressure, density, and particle velocity behind the shock were obtained. The solutions show the possible profiles as compared to other existing analyses.
Reorientierung des Drehimpulses von Li2-Molekülen beim Stoß mit Edelgasatomen / Reorientation of the Angular Momentum of Li2-Molecules due to Collisions with Noble Gas Atoms
Authors: Bormann J. , Poppe D.
Published: February 2015

Laser-induced fluorescence has been used to investigate the reorientation of the molecular angular momentum due to inelastic collisions with atoms. We report on experiments for the Li2 (1IIu)-rare gas system, where the degree of polarisation of the emitted fluorescence has been measured. Within the framework of a classical theory mean angles for reorientation have been derived. Their dependence on the collision partner and the initial and final angular momentum is discussed.
Herstellung wasserstoffdurchlässiger V-, Nb-und Ta-Folien mit Hilfe der UHV-Bedampfungstechnik / Preparation of Hydrogen Permeable Foils of V, Nb and Ta by Means of Ultra High Vacuum Techniques
Authors: Boes N. , Züchner H.
Published: February 2015

A new sample preparation method for eliminating the hydrogen impermeable oxide surface layers of base metals like V, Nb and Ta is described.

Applying UHV-techniques the metal foils are heated inductively and subsequently coated with a thin metallic Pd-film. By this method the metals are cleaned, at the same time annealed, and protected successfully against the formation of new passive layers, as is shown by x-rays, SIMS, and AES investigations.
Anwendung elektrochemischer Verfahren zur Untersuchung der Diffusion von Wasserstoff-Isotopen in V, Nb und Ta / Application of Electrochemical Techniques for Studying Diffusion of Hydrogen Isotopes in V, Nb and Ta
Authors: Boes N. , Züchner H.
Published: February 2015

After suitable preparation (improvement) of samples H (D) -diffusion coefficients of V-, Nb-, and Ta-foils can be measured reliably at low H (D) -concentrations in the temperature range 0 to 100 °C by means of an electrochemical time-lag method.

A modified strain model indicates that the tetrahedral sites in bcc lattices have to be taken as the stable positions for the dissolved hydrogen. The elementary jump in the diffusion process from one tetrahedral site to the next passes directly through a tetrahedral plane. This model describes qualitatively the experimental results concerning the sequence of the activation energies for hydrogen diffusion in the three Vb-metals [E(Ta)>E(Nb)>E(V)].
A Conductometric Study of the Bi-Hgl2 System
Authors: Šušić M. V. , Mentus S. V.
Published: February 2015

The electric conductivity of the homogeneous liquid Bi-Hgl2 system was measured in the temperature range 260-540 °C for several Bi mole fractions ranging from 0.00 to 0.38. The specific conductivity-composition isotherms are indicative of the occurrence of electronic conductivity also before reaching a bismuth concentration sufficient for a complete conversion of HgI2 into Hg2I2 · As the temperature rises the share of electronic conductivity in the total conductivity abruptly increases. Comparing the properties of this system with those of the BiI3-Bi system the conclusion is drawn that electronic conductivity in liquids is due to free metal atoms.
Näherungslösung einer verallgemeinerten Nernst-Planck-Gleichung für ein eindimensionales Membranmodell / Approximative Solution of a Generalized Nernst-Planck-equation for a one Dimensional Membran-model
Authors: Schröter J. , Stormberg H.-P.
Published: February 2015

The starting-point of this paper are generalized Nernst Planck equations, which are deduced microscopically. Using a perturbation approach a result of this equation is given for a constant external field and a membran, which has a low concentration of fixed charges. The used conditions give a zeroth approximation which describes the homogeneous electrolyte. The first approximation shows the influence of the fixed charges, the friction between ions and membran and the influence of the correlations. The flows and the concentrations are then calculated for a system with equal concentrations on both sides of the membran.
Microwave Spectrum of Acetyl Cyanide in the Ground and Excited States. I
Authors: Scappini F. , Dreizler H.
Published: February 2015

The microwave spectra of acetyl cyanide, CH3COCN, in the ground and in the two lowest excited states have been investigated. The rotational constants and the quadrupole coupling constants have been evaluated for all these states. The internal rotation parameters have been refined with respect to previous works. Evidence for a rotation-torsion -vibration interaction has been found in the spectra of the excited states.
Gitterschwingungsspektren
Authors: Lutz H. D. , Willich P. , Haeuseler H.
Published: February 2015

Force constants and normal coordinates of MnS2 , FeS2 , RuS2, RuSe2, RuTe2, OsS2 and PtP2 are calculated based on the five ir active vibrations of the pyrite lattice. By setting up a valence force field consisting of short and long range M -X, X2 -X2 and M -M stretching constants it has proved possible to obtain good agreement between experimental and calculated frequencies with expection of FeS2 and RuS2 . The force constants corresponding to the shortest metal chalcogen distances (MnS2: 0.30, RuSe2: 0.88, RuTe2: 0.62, OsS2: 1.32, PtP2: 1.22 mdyn/Å) are mainly responsible for the ir frequencies. For RuSe2 and RuTe2, the forces between adjacent X2 groups are not negligible. Whereas the force constants of OsS2 and PtP2 are of comparable strength, the forces in MnS2 are significantly weaker than those in the other compounds. The normal coordinates of MnS2, OsS2 and PtP2 , and RuSe2 and RuTe2 show significant differences according to both the contribution of the 6 symmetry coordinates to the 5 ir active vibrations and the assignment of the spectra.
Elektronentransport in nichtthermischen Edelgasplasmen
Authors: Lehrke H. , Müller K. G.
Published: February 2015

For the transport of electrons in a non-thermal, weakly ionized plasma an analytical model and a detailed numerical calculation is presented. The following transport coefficients: mean energy, characteristic energy, mobility, diffusion coefficient, excitation and ionization coefficient for He, Ne, Ar, Kr, Xe are calculated in the region of reduced electric field 0.01 V/cm Torr ≦ Elp ≦ 100 V/cm Torr. The parameters of the model are developed using the existing experimental and our numerical data. With increasing E/p the dominant energy loss of the electrons changes from elastic to inelastic collisions and here from constant to increasing effective excitation energy. Three model regions of E/p result, in which the transport coefficients can be described as a power of E/p. The data presented here provide a starting point for further investigations of similarity rules and models of non-thermal plasmas.
Monte-Carlo-Rechnungen und Messungen zur Vielfachstreuung von schweren Ionen in dünnen Folien / Monte Carlo Calculations and Measurements Concerning the Multiple Scattering of Heavy Ions in Thin Films
Authors: Zienert J. , Güttner K. , Münzenberg G.
Published: February 2015

The behaviour of energetic heavy ions in thin films is simulated by means of a Monte Carlo method taking especially into account the energy loss of the scattered particles. Based on a variably matched screened Coulomb potential the calculations yield the angular and energy distributions of the transmitted ions. The results show a good agreement with the theory of Meyer. Furthermore for keV He ions scattering distributions have been measured in C, Al and Ag, which agree fairly well with the computations, if a suitable fit of the screening parameter is used in the Monte Carlo simulations.
Hard-sphere Results from Experimental Transport Behaviour of Molten Salts and Structural Properties
Authors: Loef J. J. van
Published: February 2015

A single component hard sphere description molten halides and nitrates, applied to self-diffusion and viscosity data, has led to a hard sphere size which for a given cation depends linearly upon the anionic radius. This correlation has been used to predict viscosity coefficients of fused alkali fluorides and to estimate the effective size of the NO3
- -anion in molten nitrates. The Stokes-Einstein relationship between η and D̅ is satisfied, where D̅= (D+ +D-)/2, and this relationship in combination with the observed linear dependence of T½/η] and D̅/T½ on the molar volume can in principle be used as a criterion for data selection.
The Influence of Recombination between Holes and Reduced Redox Ions on the Efficiency of Hole Injection from Electrolytic Contacts into Organic Insulator Crystals
Authors: Willig F. , Scherer G.
Published: February 2015

The efficiency of hole injection from electrolytic contacts into organic insulator crystals is con-trolled by hole generation and hole destruction at the crystal surface through oxidized and reduced redox ions respectively and by hole escape into the crystal bulk which competes with hole destruction. By increasing the concentration of reduced redox ions from virtually zero in a suitable system the transition has been studied from the one extreme case where all the generated holes contribute to the injection current to the other extreme case where the majority of the generated holes recombines with reduced redox ions before they can escape into the crystal bulk. From the experiments one can deduce that the generated hole spends less than 10-10 s within the reaction distance of its reduced parent redox ion, at external field strengths ≧ 104 V/cm, but returns to the crystal surface during a much longer time, e.g. during about 10-8 s at an external field strength of 105 V/cm, before it can escape finally into the crystal bulk.
Einfluß der Deuterierung auf die Excimerenkinetik des Pyrens
Authors: Heidt Günther
Published: February 2015

The effect of deuteration on all six photophysical and kinetic constants of pyrene excimer formation is investigated. The rate constants of monomer and excimer emission and the rate of dissociation of the excimer are not affected by deuteration. The increase of the radiationless deactivation of the monomer (anomalous effect) agrees with the theoretical expectation. The radiationless deactivation of the excimer at various temperatures shows no effect and therefore does not take place via the excimer triplet. The decrease of the excimer formation rate can be explained by the effect of deuteration on the partition function and hence on the entropy.
Mass Dependence of the Vibrational Eigenvector Matrix Elements in XY2 (C2v) Type Molecules
Authors: Ananthakrishnan T. R. , Girijavallabhan C. P. , Joseph K. Babu
Published: February 2015

Interesting linear relationships (one for hydrides and another for nonhydrides) are found to exist between a certain parameter c characterising the vibrational eigenvector matrix L and the mass ratio my/mx in the case of bent symmetric XY2 type molecules with small mass coupling.
Torsion-Torsion Interaction in the Microwave Spectrum of Dimethylether
Authors: Lutz H. , Dreizler H.
Published: February 2015

We report an analysis of the torsional fine structure of rotational lines of (CH3)2O in excited torsional states leading to the potential parameters V3 and V′12 of a Hamiltonian for the overall-and internal rotation.
Indirect Spin-Spin Coupling Between 17O and Other Quadrupolar Nuclei in Oxyanions
Authors: Lutz O. , Nepple W. , Nolle A.
Published: February 2015

Fourier transform NMR studies of 17O, 35Cl, 51V, 53Cr, 55Mn and 95Mo are reported for aqueous solutions of the oxyanions ClO4
-, VO4
3-, CrO4
2-, MnO4
-, and MoO4
2-, partly enriched in 17O. The indirect spin-spin coupling constant between 17O and the quadrupolar central nucleus is determined:

A linear dependence of the reduced coupling constants on the atomic number of the central nucleus in the isoelectronic series VO4
3-, CrO4
2- and MnO4
- was found.
Observation of Local Mode Polaritons by Frustrated Total Reflection
Authors: Nitsch W. , Falge H. J. , Claus R.
Published: February 2015

It is shown that local modes due to C13 -and N15 -Isotopes in their natural abundances of 1.12% and 0.36% in K3Cu(CN)4 can be observed by the frustrated total reflection technique (FTR) in spite of almost vanishing mode strengths. The observation is made possible by the dispersion of the polariton brandies which reduces the reflectivity in the resonance region.