bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Field-Induced Cholesteric-Nematic Transition in Cholesteric Liquid Crystals with Homeotropic Boundary Conditions
Authors: Brokx J. , Vertogen G. , Groesen E. W. C. van
Published: February 2015

The influence of homeotropic boundary conditions on the cholesteric-nematic transition is discussed, starting from the assumption that the director field consists of only components perpendicular to the helix axis, which is directed parallel to the boundary planes. Attention is paid to the solution of Cladis and Kléman for the simpler case without magnetic field. Their solution, consisting of regularly spaced line signularities, is derived in another more transparent way. Besides it is shown that even director fields without singularities are possible. The presence of a magnetic field complicates the solution considerably. Now the relevant Euler-Lagrange equation is solved in an approximate way by partly resorting to the difference method. The usefulness of the method is demonstrated by applying this technique to the nematic-cholesteric transition and the Fréedericksz transition in nematics.
Notizen: Bäcklund Transformation Groups of Non-Linear Evolution Equations and the Painlevé Property
Authors: Steeb W.-H. , Oevel W.
Published: February 2015

We show that the group theoretical reduction of evolution equations which admit Lie-Bäcklund transformation groups does not lead in general to ordinary differential equations with the Painlevé property.
Investigations of Cosmic-Ray-Produced Nuclides in Iron Meteorites: 5. More Data on the Nuclides of Potassium and Noble Gases, on Exposure Ages and Meteoroid Sizes
Authors: Voshage H. , Feldmann H. , Braun O.
Published: February 2015

The concentrations of the cosmic-ray-produced He-, Ne-, and Ar-nuclides in samples of 31 iron meteorites have been determined by mass spectrometry. Thereby, the number of samples analyzed in this laboratory has grown to 83. A critical examination of all these results was performed. The data of at least 52 samples prove to be useful to describe the "normal" abundance patterns of cosmogenic noble gases in iron meteorites; the description is accomplished by a new system of equations that correlate some properly selected abundance ratios with one another. The correlations serve as an instrument to recognize and diagnose certain abundance anomalies (3He-or 38Ar-deficiencies) which occur in about 25% of all samples analyzed. They allow to select those data which may unhesitatingly be applied in calculations concerning the irradiation histories of the respective meteorites. Another matter of concern for establishing these histories are the cosmic-ray-exposure ages. Mass spectrometric abundance analyses on meteoritic potassium have provided new data on the 41K/40K exposure ages of about 10 iron meteorites as well as on meteoroid sizes and sample depths. For two meteorites of the chemical group IIIAB, Joe Wright Mountains and Picacho, the age values obtained are 685 and 635 Ma, respectively. The results confirm our previous conclusion that the IIIAB-irons resided originally within a more or less contiguous partial volume (metallic core?) of their parent body and were ejected in consequence of a single impact event that happened about 670 Ma ago. Another motive for the present investigation was to measure the exposure ages for meteorites of the chemical groups IIICD and HIE. However, the new information obtained on their age distributions is still inadequate to answer some old questions concerning a possible relationship to the event that produced the IIIAB-meteoroids 670 Ma ago.
Neutron Diffraction Study on the Structure of Liquid Cs-Sb Alloys
Authors: Lamparter P. , Martin W. , Steeb S. , Freyland W.
Published: February 2015

By neutron diffraction experiments the total structure factors and the total pair correlation functions of liquid Cs-Sb alloys containing 85, 75, 65, and 50 at% Cs, respectively, were determined. The structural results confirm the non metallic properties of Cs-Sb melts.

The correspondence of the nearest neighbour atomic arrangement in liquid Cs75Sb25 and in the solid compound semiconductor Cs3Sb suggests a similar type of bonding, namely by valence bonds and ionic forces simultaneously. The stability of this compound in the molten state leads to a microsegregation tendency between compound forming regions and excess Cs in the concentration range from pure Cs up to 25 at% Sb, which is established by a small angle scattering effect.

Proceeding from Cs75Sb25 to Cs50Sb50, a continuous change in the structure takes place. Covalently bonded Sb chains are formed just as found in the corresponding solid compounds ASb (A = alkali metal). An additional diffraction peak in front of the main peak of the structure factors within this composition range implies the formation of rather large molecular clusters in the alloys.
ESR of Cation Radicals of Methyl-substituted Benzenes in a CF3CCl3 Matrix
Authors: Tabata M. , Lund A.
Published: February 2015

A new matrix, 1,1,1-trifluorotrichloroethane, CF3CCl3, has been employed in radiation chemistry studies to stabilise positive ions. As a test, positive ions of benzene, toluene, orto-, meta- and paraxylene and biphenyl have been generated by y-irradiation of the solutes contained in the CF3CCl3 matrix at 77 K. The ions have been investigated by ESR, and hyperfine couplings have been obtained. The data complement and correct the splitting values obtained previously in the adsorbed state.
Millimeter-Wave Spectrum of Ethyl Acetylene Centrifugal Distortion, Coriolis Interaction and Internal Rotation
Authors: Demaison J. , Boucher D. , Burie J. , Dubrulle A.
Published: February 2015

The rotational spectrum of ethyl acetylene has been investigated between 70 and 320 GHz. A Coriolis interaction has been found between the first excited state of the methyl torsion and the C - C = C in plane deformation. Splittings of transitions in the first excited torsional state show that the barrier hindering internal rotation of the methyl group amounts to 3271 cal/mole.
The Structure Factors of Liquid Metals in Low Q Region
Authors: Waseda Y.
Published: February 2015

The low Q structure factors have been determined in the region down to Q = 0.08A-1 for liquid Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Al and In at several temperatures by x-ray diffraction with the transmission mode. The low- Q structure factor is a slowly increasing function of Q, and its profile is quite similar among the liquid metals presently investigated. The long wavelength limit value of S(Q) derived from the present experimental structural data agrees well with that calculated from the isothermal compressibility for seven metals near the melting point. A differ­ence larger than 10% was found in the cases of liquid Cs, Ca and Al.
Schwingungsspektren von Sn2P2S6 / Vibrational Spectra of Sn2P2S6
Authors: Becker Robert , Brockner Wolfgang , Wibbelmann Claus
Published: February 2015

Far infrared, infrared and Raman spectra of tin hexathiohypodiphosphate Sn2P2S6 (mono­clinic modification II) have been recorded. The observed frequencies are assigned on the basis of P2S6
4-units with C2h symmetry in the crystal. The assignment is supported by the correlation D3d (dissolved P2S6
4- ion) → C2h. DTA-data have been determined and interpreted.
ESR-Untersuchung zur N-Inversion an freien Radikalen / N-Inversion in Free Radical Molecules Studied by ESR
Authors: Fischer Volker , Bühler Werner , Scheffler Klaus
Published: February 2015

The temperature dependence of the ESR spectra of 4-[(Mono-rsp. Di-organyl-amino)-methyl]- 2.6-di-tert.-butyl-phenoxyls is studied. The observed coalescence behaviour of the hfs-parameters of the methylene protons is interpreted by N-inversion in the amine group. Thus it is shown that the μsec time scale of ESR makes it possible to study these processes near ambient temperatures. Evaluation of rate constants and activation parameters was done by computer simulation of the DESR spectra. Comparing these values with those given by DNMR methods at low temperatures show that the radical state of the molecule has no significant effect on the inversion rate constants.
Notizen: Quadrupole Coupling in the Microwave Spectrum of Ethylisothiocyanate / An Application of Microwave Fourier Transform Spectroscopy
Authors: Kasten W. , Dreizier H. , Schwarz R.
Published: February 2015

We investigated the microwave spectrum of ethyliso-thiocyanate. CH3CH2 NCS, for the nitrogen quadrupole coupling. The spectrum was first measured and assigned by Sakaizumi, Ohashi, and Yamaguchi [1]. By comparing the measured rotational constants with those resulting from an assumed structure they concluded that the synperiplanar (cis) form was measured.
Notizen: Photodissoziation von CH2J2 und CHJ3 bei 298 nm / Photodissociation of CH2I2 and CHI3 at 298 nm
Authors: Nolte Rudolf , Seibert Albert , Seidel Wolfhart
Published: February 2015

Photofragmentation of CH2J2 and CHJ3 by a pulsed laser beam (λ = 298 nm) was analysed with respect to the fragment energies (TOF distribution). From the angular distribution of the fragments shape factors b were deter­mined.
Notizen: Fluorine Diffusion and Phase Transition in Superionic Conductor KSn2F5 as Studied by 19F NMR, Electrical Conductivity and DSC
Authors: Basler W. D. , Murin I. V. , Chernov S. V.
Published: February 2015

The diffusion of fluorine in KSn2F5 has been studied by T1 and T2 relaxation time measurements of 19F NMR (200-500 K) and pulsed magnetic Field gradient tech­niques (390-480 K). Near 423 K a sharp transition into the superionic state has been found, the fluorine diffusion increasing by a factor of 4 within a range of 3 K. Conduc­tivity measurements only show a change in the activation energy.
Finite Wavetrains in a One-Dimensional Medium
Authors: Kahlert C. , Rössler O. E.
Published: February 2015

A modified Rinzel-Keller equation of reaction-diffusion type is investigated analytically. Both on the ring and on the linear fiber, the possible existence of wavetrains containing an arbitrary finite number of impulses is demonstrated. The longest wavetrain shown explicitly consists of ten pulses. Unlike other approaches, the present method varies many parameters simultaneously. An implicit algebraic equation is formulated which contains all possible wave solutions of the system. This equation is then solved with a standard technique (Powell's algorithm). The results obtained extend the findings of other authors. The method can be applied, after appropriate modification, to other piecewise linear systems, that is, to other prototype reaction-diffusion systems
Concentration Dependence of the Interdiffusion Coefficients in Molten Alkali Nitrate — Silver Nitrate Mixtures
Authors: Hahne A. , Richter J.
Published: February 2015

To measure the composition dependence of the interdiffusion coefficients in molten mixtures of alkali nitrates and silver nitrate, a wave-front-shearing interferometer, together with an initial “plane source” was used.

With this technique, the diffusion coefficients were measured in nearly differential steps in the three mixtures (Na,Ag)NO3 , (K,Ag)NO3 , and (Rb,Ag)NO3 at 300°C. The composition dependence of the diffusion coefficients D of all three systems could be described by parabolas of the form

D = a + b x 2 + c x2
2,

where x2 denotes the mole fraction of the silver nitrate. The three coefficients a,b, and c all show a clear proportionality to the radii of the akali ions. Thus an extrapolation to the not measured systems (Li, Ag)NO3 and (Cs, Ag)NO3 was possible.
Determination of a High Potential Barrier Hindering Internal Rotation from the Ground State Spectrum
Authors: Stahl W. , Dreizler H. , Hayashi M.
Published: February 2015

We present an analysis of the rotational spectrum of ethylchloride-35Cl in the ground state. The 35Cl-hfs analysis was extended and the barrier to internal rotation determined from narrow splittings of high J-transitions.
A Method of Calculating Bound States in a Unified Field Model
Authors: Großer D. , Hailer B. , Hornung L. , Lauxmann T. , Stumpf H.
Published: February 2015

In a model in which the usual elementary particles (leptons, quarks, photons, weak bosons, gluons, and so on) are bound states of truly elementary fermions we present a method for the calculation of the masses of these bound states. The kinetic energy of this model contains derivatives of second order so that the four-fermion interaction becomes renormalizable. The method uses explicit representations for the Hilbert space vectors of bound states.
Structure of Ni-B-Melts by Means of X-Ray Diffraction
Authors: Nassif E. , Lamparter P. , Sedelmeyer B. , Steeb S.
Published: February 2015

The structural results for molten Ni81B19 are compared with the structure of a metallic glass which can be obtained at the same composition by rapid quenching the melt within a melt spin equipment. Structural relationship exists between the molten and the amorphous state. This feature follows especially from a marked asymmetry of the second maximum of the structure factor obtained from the melts, to which corresponds the splitting up of the second maximum in the total structure factor of the amorphous specimen. With the Ni53B47- and the Ni43B57 -melts which don't belong to the concentration range of glass-forming Ni-B-melts no peculiarities in the range of the second maximum of the structure factor were observed.
Vibronic Ground State Rotational Spectrum of 3-Bromothiophene
Authors: Hübner Dirk , Fliege Eckhard , Sutter Dieter H.
Published: February 2015

The rotational spectrum of 3-bromothiophene was investigated in the frequency range between 8 and 18 GHz by use of a microwave Fourier transform spectrometer. Both a- and b-type spectra were assigned for the vibronic ground state. Rotational constants, quartic centrifugal distortion constants and quadrupole coupling constants were obtained for the 79Br- and 81Br-isotopic species. For the analysis, the effective rotational Hamiltonian including centrifugal distortion in the form of Van Eijck's symmetric top reduction and bromine quadrupole coupling was set up in the coupled basis of the limiting symmetric top, J, K, I, F, MF>, and was diagonalized numerically. Spin rotation interaction was neglected
Microwave Spectrum and Nuclear Quadrupole Interaction of 3-Bromothiophene in Excited Vibrational States
Authors: Sasada Yoshiaki
Published: February 2015

The rotational spectra of 3-bromothiophene in the excited states of two vibrational modes were observed and the rotational constants, the centrifugal distortion constants, and the nuclear quadrupole coupling constants were determined. The wave numbers of the two vibrational modes were evaluated to be 210 cm-1 and 320 cm-1 by measuring relative intensities of the ground and excited vibrational transitions. Variations in the inertia defect for each of the vibrational modes are compared with the results of the approximate calculation.
Damage Tensors and Tensors of Continuity in Stress Analysis
Authors: Betten J.
Published: February 2015

Starting from a third order skew-symmetric tensor of continuity to represent area vectors (bivectors) of Cauchy's tetrahedron in a damaged state, a second order damage tensor is found which has the diagonal form with respect to the considered coordinate system.

The second part of the paper is concerned with the stresses in a damaged continuum. Introducing a linear operator of rank four a net-stress tensor is formulated. This tensor can be decomposed into a symmetric part and into an antisymmetric one, where only the symmetric part is equal to the net-stress tensor introduced by Rabotnov [7].

In view of the formulation of constitutive equations the non-symmetric property of the actual net-stress tensor is a disadvantage. Therefore, a pseudo-net-stress tensor is introduced, which is symmetric.
The dissociation of salicylic, 2,4-, 2,5-, and 2,6-dihydroxybenzoic acids in methanol-water mixtures at 25 °C
Authors: Poulias G. , Papadopoulos N. , Jannakoudakis D.
Published: February 2015

The dissociation constants and the molar conductivities at the limit of zero concentration of salicylic, 2,6-, 2,5-, and 2,4-dihydroxybenzoic acids have been determined in water-methanol mixtures at 25 °C. The experimental data have been analysed with the Lee and Wheaton conductance equation.
New Variational Formulation of Maxwell-Vlasov and Guiding Center Theories Local Charge and Energy Conservation Laws
Authors: Pfirsch D.
Published: February 2015

A new variational formulation of Maxwell-Vlasov and related theories is given in terms of a common Lagrangian density for both the "Vlasov particles" and the Maxwell fields. This formulation is used to derive in a consistent way, on the one hand, correct charge and current densities and, on the other, corresponding energy and energy flux densities. All of these densities generally show in addition to particle like contributions electric polarization and magnetization terms. By some limiting procedure collisionless guiding center theories with polarization drifts included are also treated. In this way local energy conservation laws are formulated for such theories, which has not been possible up to now
Fragmentation Rates of Aromatic Radical Anions and the π*— σ* Orbital Crossing Point
Authors: Villar H. O. , Castro E. A. , Rossi R. A.
Published: February 2015

The reaction coordinate of the fragmentation of aromatic radical anions with nucleofugal groups was studied by the INDO and MNDO techniques. The reaction coordinate turned out as the stretching between the nucleofugal group bonded to the carbon atom of the aryl moiety. It was found that to fragment a π* radical anion, the odd electron has to be transferred to the σ* molecular orbital of the aryl-nucleofugal bond by an orbital crossing, which is reached by the lengthening of this bond. There is a qualitative agreement between the length of the bond to reach the orbital crossing point and the experimental fragmentation rates of the aromatic radical anions. Finally, some considerations about the σ-π coupling are made, since it is defining the possibility of a transfer from the π* to the σ* molecular orbital.
Vibrational Dependence in the Molecular G- and Susceptibility- Tensors of Sulfur Dioxide
Authors: Hübner D. , Sutter D. H.
Published: February 2015

The high field rotational Zeeman effect of SO2 molecules in the first excited state of the bending vibration has been studied under high resolution. Within the experimental uncertainties no υ-dependence is observed for the magnetic susceptibility anisotropies, and the observed υ-dependence in the g-tensor elements appears to be essentially caused by the υ-dependence of the rotational constants. If this finding may be generalized to all small amplitude vibrations, prospects for sign of the electric dipole moment determinations from rotational Zeeman effect studies of different isotopic species are brighter than expected hitherto.
Sein oder Nichtsein als Grundfrage der Quantenphysik / To he or not to be as basic question in quantum physics
Authors: Bopp Fritz
Published: February 2015

The question is often asked how to interprete quantum physics. That question does not arise in classical physics, since Newton's axioms are immediately connected with basic ideas and experiences. The same is possible in quantum physics, if we remember how elementary particle physicists describe their experiments.

As Helmholtz has pointed out. the basic assumption of classical physics is that of geneidentity. That means: Bodies remain the same during their motion. Obviously, that is no longer true in quantum physics. Particles can be created and annihilated. Therefore creation and annihilation must be considered as basic processes. Motion only occurs, if a particle is annihilated in a certain point, if an equal one is created in an infinitesimally neighbouring point, and if this process is continuously going on during a certain time. Motions of that kind are compatible with the existence of some manifest creation and annihilation processes.

If we accept this idea, quantum physics can be derived from first principles. As in classical physics, we know therefore what happens from the very beginning. Thus questions of interpretation become dispensable.

A particular mathematical method is used to exhaust continua. The theory is formulated in a finite lattice, whose point density and extension equally go to infinity. All calculations are therefore performed in a finite dimensional Hilbert space. The results are however related to an infinite dimensional one. Earlier calculations may, therefore, be essentially correct, though they must be rejected in theories which are based on manifestly infinite dimensional Hilbert spaces. Here limiting processes do not occur in the state space. They are only admissible for numerical results.
Nuclear Magnetic Resonance Studies of Liquid Semiconducting Sb-Te Alloys
Authors: Hinkel V. , Ploumbidis D.
Published: February 2015

Nuclear magnetic resonance studies of 123Sb and 121Sb in the SbxTe1-x liquid alloy system are described. Interest is focussed on the concentration dependence of the Knight shift and the NMR linewidth. Measurements of the Knight shift and linewidth have been carried out over the entire concentration range at elevated temperatures (900-1100) K. Knight shifts of 123Sb and 121Sb, measured to high precision, show hyperfine structure anomaly. Both. Knight shift and linewidth show strong dependence on the alloy concentration and extreme behavior at the concentrations 40 at.% Sb and 50 at.% Sb. respectively. The experimental results are discussed in terms of modes concerning the electronic structure of liquid semiconductors.
Diffusion Measurements with the Gravimetric Method in Solutions and in Molten Alkali Nitrates
Authors: Graaf F. van der , Ketelaar J. A. A.
Published: February 2015

The gravimetric method of interdiffusion measurement from a quartz frit is developped into an accurate general method. It is applied to a number of electrolyte solutions; for iodides and bromides a correction for the adsorption is applied. For the molten alkali nitrate systems (K-Cs)NO3 at the molar fractions xCs = 0.0 and xCs = 0.1, (Na-Cs)NO3 at xCs = 0.0 and xCs = 0.1. (Na-Rb)NO3, at xRb = 0.0 and xRb = 0.1 and (Na-K)NO3 at ,xNa = 0.0, xNa = 0.3 and xNa = 1.0 the interdiffusion coefficient is determined over the temperature range of 600-723 K. The values obtained here are discussed in comparison to those from literature.
A Simple Approximation for Axially Symmetric Diffraction of Plane Shocks by Cones
Authors: Yu Shanbing , Grönig Hans
Published: February 2015

By Whitham’s shock dynamics, axially symmetric diffraction problems of plane shocks by cones are reduced to the integration of a system of ordinary differential equations. This paper gives a simpler approach. Approximating the Mach stems by circular arcs, the problems are reduced to the solution of algebraical equations, and the calculating is much simplified. In the cases of small or large cone angles the estimation is even easier.
A Second Integral of Motion in a Triaxial Galaxy
Authors: Caranicolas N.
Published: February 2015

We construct a formal second integral of motion in a bisymmetrical potential field describing the motion on the plane of symmetry of a triaxial galaxy. We also check the constancy of the second integral adding higher-order terms which are found using a computer program.
A Simplified Form of the Hermitianizing Matrix for the Half Integer Spin Bhabha Fields
Authors: Koutroulos C. G.
Published: February 2015

The hermitianizing matrix of the Bhabha fields for s = half integer can be simplified to the form f(x, s) = (-1)s-p-1/2 and as a result the charge of these fields for s > 1/2 is indefinite
Luminescence of 5-Phenyltetrazole and its Derivatives. Part II. Phosphorescence
Authors: Gryczyński I. , Kawski A. , Grzonka Z. , Rażyńska A.
Published: February 2015

The phosphorescence spectra, mean lifetimes of phosphorescence and ratios of phosphorescence/ fluorescence quantum yields have been measured for 5-phenyltetrazole and its three methyl derivatives in a polyvinyl alcohol film over the temperature range of (77-250) K. Temperature responses of the non-radiative intersystem crossing constant. KST, and the non-radiative triplet state deactivation constant, km, have been investigated on the basis of these measurements. The energy of activation for the non-radiative transitions has been determined. With the methyl 5-phenyltetrazoles, the thermal deactivation of the triplet state, contrary to the intersystem crossing, has been found to be influenced by the position of the methyl substituent in the phenyl ring.
On the Mechanism of Spin Reorientation in YIG:Si
Authors: Rudowicz Czesław
Published: February 2015

The magnetocrystalline anisotropy theory developed earlier by us and based on a novel energy level model for Fe2+ in YIG:Si(Ge) is used here to study the mechanism of spin reorientation in YIG:Si. Single-ion anisotropy with a uniform distribution of Fe2+ ions indicate a broad spin reorientation which turns out to be due to the higher-order cubic terms K3 and K4. It is found that the completion temperature (T2) of the spin reorientation is strongly influenced by K4 thus indicating an inadequacy of the approach based on K1, K2 and K3 only. From the single Fe2+ ion anisotropy results we propose a two-center model which implies a new mechanism of the spin reorientation in YIG: Si. The bulk onset (T1′) and completion (T2′) temperatures are linked to the relative number (a) of the near Fe2+ sites. Spin orientation diagrams in the plane a - T are established for the total Fe2+-Fe3+ system for a wide range of the parameters involved. The two-center model accounts well for the bulk experimental temperatures T1′ and T2′ in YIG: Si and for the absence of spin reorientation in samples having Si-content less than 0.18. The total magnetization M is predicted not to rotate smoothly between the [100] and [111] direction. There exists an upper critical angle beyond which M switches sharply to [111] as the temperature approaches T2′. Comparison with the previous model which requires a nonuniform distribution of Fe2+ ions is also discussed.
Beobachtungen von Stapelfehlordnungen bei der Oxydation der zweiten zur ersten Stufe des Graphithydrogensulfats / Observation of stacking disorder during the oxidation of second stage to first stage graphite hydrogensulfate
Authors: Shin Ko Young , Boehm Hanns-Peter
Published: February 2015

Graphite has been oxidized to graphite hydrogensulfate with (NH4)2S2Og in concentrated H2SO4. The stage 2 compound formed very rapidly, but further oxidation to stage 1 could be followed conveniently. X-ray diffraction of the intermediate phases showed nonintegral (00l)-reflections indicative of partial interstratification disorder. The interlayer spacing of the stage 1 compound increased with continued oxidation. The degree of oxidation as function of oxidation time has been determined from the position of the minima in the reflectance spectra. The density of the compounds and the ratio of acid molecules to anions in the intercalated layers has been estimated using these data and those of buoyancy measurements. There is a minimum in packing density early in the formation of the first stage. The kinetics of intercalation seems to be first order with respect to the free interlayer spaces.
Gitterdynamik von Verbindungen mit Matlockit-Struktur / Lattice Dynamics of Compounds with Matlockite-Type Structure
Authors: Haeuseler H. , Schneider G.
Published: February 2015

On the basis of the rigid ion model and polarizable ion model, lattice dynamical calculations have been carried out for the fluorohalides BaFCl and BaFBr and for the oxyhalides LaOCl, LaOBr, YOCl, SmOCl and GdOCl which crystallize with the tetragonal Matlockite-type structure (PbFCl-type). The results of these calculations: short range force constants, effective dynamical charges and polarizabilities are communicated and discussed. Bonding in the fluorohalides is much more ionic than in the oxyhalides.
Note on Algebraic Structure Count
Authors: Gutman Ivan
Published: February 2015

Three recursion relations for the algebraic structure count are deduced, which are closely analogous to the well-known recursion relation for the number of Kekulé structures. An efficient graphical method for the calculation of algebraic structure count is proposed.
Kinetics and Mechanism of Hübnerite (MnWO4) and Ferberite (FeWO4)Crystallization under Hydrothermal Conditions
Authors: Buhl J. Chr. , Willgallis A.
Published: February 2015

The kinetics of the crystallization of hiibnerite (MnWO4) and ferberite (FeWO4) was studied by hydrothermally reacting the metal (II)-chlorides and sodium tungstate in a special autoclave at two temperatures (300 °C. 400 °C) and a pressure of 1 kbar. The rates of crystallization were determined by continual removal of the reactants from the autoclave. At both temperatures, the decrease of tungstate concentration in solution followed at first order reaction. The rate constants of the reactions were calculated and the Jerofejev-equation was used to describe the kinetics. The rate of hiibnerite formation was larger and increased faster with temperature. This should affect the formation of mixed crystals by initiating a shift of the composition towards higher MnWO4/FeWO4 ratios and might well account for a zonation or inhomogeneity of natural wolframites.
The Quantum Mechanical Measuring Process as a Scattering Phenomenon Inducing a Collective Coherent Motion
Authors: Requardt Manfred
Published: February 2015

In this paper we want to discuss the quantum mechanical measuring process within the realm of many body quantum theory. Our starting point is to consider this process as a special scattering phenomenon where within one of the partners, i.e. the many body measuring device, a collective coherent motion is induced by the interaction with the microobject. We start our investigation with the many body system having a large but finite number N of degrees of freedom which is the real situation. We then study in detail what will happen in the limit N → ∞, however emphasizing that this transition is actually only performed in the mind of the observer. This implies that certain tail events together with their phase correlations have to be truncated. We show that the dichotomy "pure state" versus "mixture" as outgoing scattering states will vanish in this limit in so far as it has no observable consequences provided one is only interested in the state of the microobject. Furthermore, we discuss the role of the observer, the notion of "event", the relation between single preparation and ensemble picture, and the so-called "reduction of the wave function" in the light of our approach, i.e. explaining the phenomena accompanying the measuring process in terms of many body quantum theory.
Investigation of T1-Relaxation by a Microwave Pulse Technique for HCCC15N Rotational Transitions
Authors: Bomsdorf H. , Mäder H.
Published: February 2015

The pressure dependence of 1/T1 has been measured with a bridge type superhet spectrometer at room temperature for the rotational transitions (J, |M| ) = (1, 0)-(2, 0), (1, 1)-(2, 1), (2, 0) -(3,0), (2. 1)-(3, 1) and (2, 2)-(3, 2) of cyanoacetylene. HCCC15N. by using a π, τ, π/2 microwave pulse sequence method. In addition to the measurements on the pure gas, T1-relaxation has also been investigated for mixtures with H2, He, Ne and Ar. The results are used to derive linear combinations of rate constants for collision-induced transfer of rotational energy between |M| - resolved rotational levels of HCCC15N.
Transport Numbers of Molten (Cs,Ag)J and (Alk,Ag) Br Mixtures, Alk = Na, K, Rb, Cs
Authors: Richter J. , Seifert A.
Published: February 2015

The transport numbers of the molten systems (Cs,Ag)J, (Na,Ag)Br, (K,Ag)Br, (Rb,Ag)Br, and (Cs,Ag)Br have been determined by e.m.f. measurements on concentration cells with transference. We find again an inversion point (the mobility ratio reverses at a certain molar ratio) within experimental accuracy with the exception of (Na,Ag)Br and (K,Ag)Br, where the composition dependence is close to tAlk = xAlkX·
Three Dimensional Structure of the Copper Complex of N,N'-Bis-salicyloyl-hydrazine
Authors: Gentzkow Wolfgang von , Knapek Erwin , Dietrich Isolde , Formanek Helmut
Published: February 2015

N,N'-Bis-salicyloyl-hydrazine (BSH) is a very efficient copper deactivator. In this study the three dimensional structure of the copper-BSH complex was investigated with a cryotransmission- electron microscope and sterical and energetic calculations.

The neat copper-BSH complex forms a nearly amorphous polymer. By absorption of e.g. gaseous ammonia a hexagonal structure shows up without fundamentally transforming the conformation of the complex. The most dominant lattice periodicities are 0.9 and 1.1 nm as obtained by electron microscopical imaging, electron diffraction and sterical calculations. The model shows that copper is very well shielded in the complex by the surrounding BSH-molecules. Due to this, copper is perfectly deactivated.
Protonation of the Trimethylated Pyrichrominium Ion
Authors: Koput J. , Marciniak B. , Paszyc S.
Published: February 2015

pK

Spectroscopic manifestations of protonation of the trimethylated pyrichrominium ion studied previously experimentally [1] are investigated using a semiempirical INDO/S Cl method. Singlet and triplet energy levels of the free ion and several protonated species are calculated, and transition energies and oscillator strengths are compared with experimental spectra. Calculated charge densities on nitrogen atoms are correlated with experimental values for the ground and lowest excited singlet and triplet states. The possibility of the proton transfer reaction (phototautomerization) in the lowest excited singlet state of monoprotonated species is discussed on the basis of INDO/S Cl calculations, fluorescence and absorption spectroscopy.
Thermal Instability of a Compressible and Partially Ionized Plasma
Authors: Sharma R. C. , Misra J. N.
Published: February 2015

The compressibility and collisional effects on thermal instability of a composite medium are considered. The effect of compressibility is found to be stabilizing. In contrast to the nonoscillatory modes for (Cp/g) ß > 1 in the absence of a magnetic field, Cp, ß and g being the specific heat at constant pressure, a uniform adverse temperature gradient and the acceleration due to gravity respectively, the presence of a magnetic field introduces oscillatory modes in the system. The sufficient condition for non-existence of overstability is found. The magnetic field is found to have a stabilizing effect on the system for (Cp/g) ß > 1.
Magnetische Monopole in vereinheitlichten Eichtheorien
Authors: Mielke Eckehard W.
Published: February 2015

Although refuted for a long time as a monstrosity, today’s concepts in elementary particle physics necessitate it on theoretical grounds: The existence of isolated elementary magnetic north- or south poles.

If compared with a proton, the mass of such a monopole is estimated to be gigantic; comparable to that of an amoeba. Under the impact of the empirical success of unified gauge models, the search for monopoles has been steadily enforced with the aid of new detection methods.
Hyperchaos and Julia Sets
Authors: Rössler O. E. , Kahlert C. , Parisi J. , Peinke J.
Published: February 2015

Julia sets are self-similar separatrices of the coast-line type found in noninvertible 2-D maps. The same class of maps also generates hyperchaos (chaos with two mixing directions). Smale’s notion of a “nontrivial basic set” provides a connection. These sets arise when a chaotic (or hyperchaotic) attractor “explodes”. In the case of more than one escape route, this set becomes a “fuzzy boundary” (Mira). Its projection as the map becomes noninvertible (1-D ) is a “Julia set in 1 D ”. In the analogous hyperchaos case the 2-D limiting map contains a classical Julia set of the continuous type. An identically looking set can also be obtained within a non-exploded hyperchaotic attractor, however, as a “cloud”. Julia-like attractors therefore exist. The theory also predicts Mandelbrot sets for 4-D flows. Julia-like behavior is a new, numerically easy-to-test for property o f most nontrivial dynamical systems.
Upper Bounds for the Total π-Electron Energy of Benzenoid Hydrocarbons and Their Relations
Authors: Ciosłowski J. , Gutman I.
Published: February 2015

Upper bounds for the total π-electron energy of benzenoid hydrocarbons, depending on the number of carbon atoms and carbon-carbon bonds, are examined and several of their properties established.
Effect of Magnetic Quantization on the Effective Electron Mass in Bismuth
Authors: Ghatak K. P. , Mondal M.
Published: February 2015

An attempt is made to derive an expression for the effective electron mass along the direction of a magnetic field in bismuth under magnetic quantization by using the generalized dispersion relation of the conduction electrons as proposed by Meclure and Choi. It is found that the oscillatory quantum number dependent behaviour of the effective electron mass at the Fermi level in bismuth is solely due to band non-parabolicity and is a characteristic feature of the above model.
Some Molecular Integrals over Ellipsoidal Hermite-Gaussian Functions
Authors: Maksić Z. B.
Published: February 2015

Some molecular integrals over ellipsoidal Hermite-Gaussian functions relevant for SCF calculations are considered. It is shown that all integrals can be expressed in a closed form if the H nzA (axAXA) H nyA (ayA yA) H nzA (azA zA) exp (-br2
A basis set is employed. It appears also that this type of functions is convenient for the calculation of electric properties of molecules. Finally, a relation between the H G and harmonic oscillator functions is established.
Changes in Composition by Countercurrent Electromigration in a Gradient of Temperature and/or Composition
Authors: Klemm Alfred , Arnold Lundén Arnold
Published: February 2015

Unexpected previous findings in countercurrent electromigration experiments are explained and a new measuring technique based on dual temperature or dual composition experiments is proposed.
Electronic Properties of Triplet States of Azabenzenes
Authors: Vogler Helmut
Published: February 2015

The electronic properties of the ππ* and nπ* triplet states of azabenzenes are studied by means of semiempirical calculations of zero-field-splitting parameters.
High Enrichment of Li-6 by Countercurrent Electromigration in Molten LiNO3 with Molten NH4NO3 at the Cathode
Authors: Okada Isao , Gundo Kumido , Nomura Masao , Fujii Yasuhiko , Okamoto Makoto
Published: February 2015

Based on a previously proposed principle, 6Li was enriched from the original abundance 7.4% to 82% with a cell of a new type. Ammonium nitrate melt was used in the relatively large cathode compartment. The enrichment took place around the rather sharp boundary between LiNO3 and NH4NO3 near the end of a nearly horizontal separation tube opening to the cathode compartment. In 31 days’ electromigration no serious corrosion problem was encountered.
Number of Kekulé Structures as a Function of the Number of Hexagons in Benzenoid Hydrocarbons
Authors: Cyvin S. J. , Gutman I.
Published: February 2015

The possible values of the number of Kekulé structures ( K) of a benzenoid hydrocarbon with h hexagons are examined. For normal benzenoids the lowest possible value of K is h + 1. Based on this result the benzenoid systems which have K up to 24 are determined. A number of results concerning enumeration and classification of benzenoid systems is reported.
Electric Conductivities of Binary Molten (K, Ag)Cl, (Cs, Ag)Cl, (K, Ag)Br, (Na, Ag)I, (K, Ag)I, and (Cs, Ag)I Mixtures
Authors: Boßmann H.-P. , Hildebrandt A. , Richter J.
Published: February 2015

The specific electric conductivities of the binary molten mixtures (K,Ag)Cl, (Cs,Ag)Cl, (K,Ag)Br, (Na, Ag)I, (K, Ag)I, and (Cs, Ag)I are determined as functions of temperature and composition. For 950 K, 1000 K, 1050 K, and 1100 K the equivalent conductivities and the ionic conductivities of the cations with reference to the common anion are evaluated in dependence on the composition.
Quadrupole Interaction in Metals: Nuclear Methods
Authors: Haas H.
Published: February 2015

Nuclear techniques offer the unique possibility to investigate the hyperfine interaction at

isolated impurities in matter. Electric field gradients at impurities in metals have now been
determined in numerous systems. An overview of the various techniques - perturbed angular
correlation/distribution. Mössbauer spectroscopy, nuclear orientation - is presented. For sp impurities
in simple metals the results show a very clear pattern that can be understood in terms
of the local density of states. Several recent applications of nuclear methods to more complicated
systems like alloys, point defects, diffusion, and surfaces are discussed.
Nuclear Quadrupole Resonance Studies of Chelated Antimony Complexes. Part III. The Carboxylates: RCO2SbCl4
Authors: Gerard-Dion Claudine , Rupp-Bensadon Joyce , Lucken Edwin A. C.
Published: February 2015

The 35Cl, 121Sb and 123Sb resonance frequencies for seventeen tetrachloro(carboxylato)antimony V compounds, RCO2SbCl4, are reported. The results confirm the difference in the effects of the substituent on the equatorial chlorine atoms and the axial chlorine atoms of the SbCl4 group, previously remarked in Parts I and II of this series, and this effect has been put on a more quantitative basis by correlating the observed frequencies with the pK’s of the corresponding acids.

The compounds with R = isopropyl and R = cyclopropyl both show a phase change in the region of 140 K which may correspond to reorientation of the substituent about the R - CO2 axis.
NQR Parameters in Incommensurate Cs2CdBr4 and Cs2HgBr4 Crystals
Authors: Nakayama Hirokazu , Nakamura Nobuo , Chihara Hideaki
Published: February 2015

The temperature dependence of the 81Br spin-lattice relaxation times for Cs2CdBr4 and Cs2HgBr4 was measured in the low temperature and the commensurate phases. For the commensurate phase of Cs2CdBr4 rapid shortening of the T1 of νB ~ νC was observed on approaching the “lock-in” transition point. It is probably due to an anisotropic critical fluctuation. On the other hand, T, in the low temperature phase of Cs2HgBr4 behaves like an order parameter but no critical decrease of T1 was observed in the commensurate phase.
A 14N FT-NQR Investigation on Solid Pyridine and Pyridine-D5
Authors: Ambrosetti Roberto , Angelone Rocco , Murgich Juan
Published: February 2015

The FT-NQR spectra of 14N in both pyridine and pyridine-D 5 show four sets of resonance lines at - 196 °C, which disappear reversibly at - 191.5 °C and - 187 °C, respectively. This is interpreted as a phase transition, possibly of the order-disorder type. The NQR results can thus be reconciled with X-ray measurements at - 180 °C which suggested a single site for pyridine. The similarity of the NQR spectra of different samples of both compounds, frozen and cooled with widely different procedures, suggests that the high multiplicity of the NQR spectra is not the result of coexistence of different crystal phases. It is shown that previously available data from IR, Raman and NQR spectroscopies can all be put in a non-contradictory scheme.
Temperature and Pressure Variation of the Cl-NQR in A2PbCl6-Crystals
Authors: Seo Y. M. , Pelzl J. , Dimitropoulos C.
Published: February 2015

The 35Cl NQR frequency and spin-lattice relaxation rate in the compounds A2PbCl6 (A = Cs, Rb, NH4, K) have been investigated in the range 4.2 K to 500 K, and as a function of pressure at room temperature. NQR experiments conducted on (K: NH4)2PbCl6 mixed crystals have been used to complete the NQR-frequency versus temperature diagram of K2PbCl6, revealing two structural transitions at Tc1 ≅ 358 K and at TC2 ≅ 333 K.
A Spherical Tensor Method for Pure NQR
Authors: Krishnan M angala S. , Sanctuary B. C.
Published: February 2015

The multipole operator technique is used to exploit the rotational invariance of the Hamiltonian. The technique and its effectiveness for the pure quadrupole hamiltonian with arbitrary asymmetry parameter are discussed for spins ≦ 5/2. The time evolution of the quadrupolar alignment tensor is presented analytically for various spins. The dynamics of the full density matrix are given.
Relaxation of Lattice Imperfections as Studied by Chlorine NQR
Authors: Hashimoto Masao , Adachi Masahiro , Mano Koichi
Published: February 2015

The intensities, linewidths, and frequencies of 35Cl NQR signals in 6-nitro-2,4-bis(trichlorom ethyl)-benzo[1,3]dioxine were found to vary remarkably depending on the crystallization methods and annealing. This finding was correlated to the degree of crystal disorder. For a sample obtained by slow crystallization from an ethanolic solution of the compound, the growth of the height of the NQR absorption signal due to annealing was measured as a function of the isothermal annealing time. A kinetic analysis of the growth process gave an activation energy of approx. 110 kJ/mole for the relaxation process of the imperfection dominating the NQR signals. The dimorphism of the compound and the magnitude of the activation energy suggest the presence of misoriented molecules accompanied by vacancies in the crystal lattice of the stable phase.
Anomaly of Nuclear Quadrupole Relaxation in Cu2O Prepared at Low Temperatures
Authors: Kasprzak J. , Lus J. , Pietrzak J.
Published: February 2015

The 63Cu and 65Cu NQR transitions in powder samples of cuprous oxide have been investigated from 77 to 500 K and at room temperature after annealing up to 1100 K Significant differences in T1 , NQR linewidth Δv, and their temperature dependences were found among the samples prepared in different ways. For C u20 samples obtained in low temperatures (below 380 K), the temperature dependence of T1 below 380 K is o f activation character with Ea = 0.07 eV. These results are interpreted in terms of an electron hopping mechanism. Thermal processing of these samples permits to obtain irreversible electronic state and then the spectroscopic parameters are the same as for the samples obtained in high temperatures (above 1320 K).
Electric Field Nuclear Magnetic Resonance (Application to Nuclear Quadrupole Coupling)
Authors: Ruessink B. H. , MacLean C.
Published: February 2015

The technique of electric field NMR is outlined in terms of theoretical approach and of experimental method. As an illustration, new and recent values for quadrupole coupling constants measured in the liquid state are reported. They are compiled together with observations from the solid and the gas. A discussion concerning the differences between the phases is briefly given. Experimental results of quadrupole coupling constants for all of the three phases are still scarce.
Nuclear Quadrupole Resonance: The Present State and Further Development
Authors: Smith J. A. S.
Published: February 2015

The importance of nuclear electric quadrupole interactions in chemistry, both present and future, depends very much on their power to resolve problems in electronic structure and molecular dynamics. Fortunately, the subject, by its very nature, is “multinuclear”; even if the ground state of a given nucleus is non-quadrupolar, there often exist excited nuclear states which are, an example being 19F, for which quadrupole coupling constants are now being published from angular correlation measurements. Other new techniques are constantly extending the range of the experiments, recent examples being the use of SQUID magnetometers to detect acoustic 121Sb and 123Sb quadrupole resonance in antimony metal and Fourier transform quadrupole resonance spectroscopy based on fast field cycling to measure 2H quadrupole interactions in powders. Recently, much work on quadrupole interactions in solids of half-integral spin nuclei such as 17O or 27Al has been pursued in two different ways; by quadrupole double resonance in natural abundance, and nuclear magnetic resonance in very high magnetic fields, for which enrichment of low-abundance nuclei such as 170 is often required. In the liquid phase, measurements are now sufficiently reliable for comparisons of changes in the nuclear electric quadrupole tensor from gas to liquid and solid phases to be made. The new methods of partial alignment of polar molecules in the liquid phase in strong electric fields, or magnetically anisotropic molecules in high magnetic fields, seem certain to contribute to these developments.