bluuebunny/crossref_metadata_2025 huggingface dataset:
Notiz: Temperature Dependence of the Proton NMR Spectra of Bitumen
Authors: Dolinšek J. , Lahajnar G. , Marin B. , Pirš J. , Sepe A. , Slak J. , Milia F. , Blinc R.
Published: February 2015

The temperature dependence of the proton NMR spectra of bitumen samples of different origin and quality has been measured between 400 K and 80 K. Whereas the linewidths of different samples are essentially identical above 340 K and below 240 K, there is a significant difference in the linewidth transition region around room temperature.

The results show that it is possible to discriminate between bitumen samples of different composition and quality by simply measuring the proton NMR linewidth at room temperature.
A Generalized Debye Scattering Equation
Authors: Wieder Thomas , Fuess Hartmut
Published: February 2015

The Debye scattering equation for amorphous material and the Laue scattering equation for crystalline material follow from different assumptions on the orientation distribution of the interatomic distance vector rμ,ν. A generalization of these assumptions leads to a new scattering equation which is presented here.
Low Frequency Dielectric Relaxation Process in Liquid Crystals with Nematic and Liquid-Like Smectic Phases
Authors: Urban S. , Kresse H. , Dąbrowski R.
Published: February 2015

Results of dielectric studies of the low frequency relaxation process in several substances exhibiting nematic -smectic C polymorphism are presented. They are compared with the data obtained re-cently for substances with nematic-smectic A and nematic-smectic B phase sequences. It was found that the rate of molecular reorientation around the short axes does not change at the transition between the nematic and a liquid-like smectic phase (Sm A, Sm C), whereas it is considerably retarded at that of the nematic-solid-like smectic (Sm B) phase. However, the activation barrier for this motion is markedly lower in the orthogonal smectics (Sm A, Sm B) than in the nematic and Sm C phases. The analysis of numerous experimental data on the activation enthalpy in the nematic phase shows that the Arrhenius equation conforms better with results than the Diogo-Martins approach, if the nematic range exceeds 10 K.
Density and Electrical Conductivity of Molten (2K, Fe)Cl2, (2K, Co)Cl2, and (2K, Ni)Cl2
Authors: Red’kin A. A. , Salyulev A. B. , Smirnov M. V. , Khokhlov V. A.
Published: February 2015

The density and electrical conductivity of molten (2K, Fe)Cl2, (2 K, Co)Cl2 and (2K, Ni)Cl2 have been investigated. The density was measured by the maximum bubble pressure and dylatometric methods, the electrical conductivity by an AC technique. The molar volume and equivalent conductance were calculated.
Long-range Structures in Bulk Water. A Molecular Dynamics Study
Authors: Kohlmeyer Axel , Witschel Wolfgang , Spohr Eckhard
Published: February 2015

We present recent calculations of pair correlation functions and partial structure factors derived from molecular dynamics simulations of large bulk water systems (up to 12 167 water molecules). We observe small amplitude oscillations of the pair correlation functions in the range between 10 and 20 Ä.
Evaluation of Luminescence Decay Measurements Probed on Pure and Doped Pt(IV) Hexahalogeno Complexes. II. Molecular Properties Obtained from Temperature Dependent Lifetime Curves
Authors: Biertümpel Ingo , Schmidtke Hans-Herbert
Published: February 2015

Lifetime measurements down to nearly liquid helium temperatures are used for determining energy levels and transition rates between excited levels and relaxations into the ground state. Energies are obtained from temperature dependent lifetimes by fitting experimental curves to model functions pertinent for thermally activated processes. Rates are calculated from solutions of rate equations. Similar parameters for pure and doped Pt(IV) hexahalogeno complexes indicate that excited levels largely belong to molecular units. Some of the rates between excited states are only somewhat larger than decay rates into the ground state, which is a consequence of the polyexponential decay measured also at low temperature (2 K). In the series of halogen complexes, the rates between spinorbit levels resulting from 3T1g increase from fluorine to bromine, although energy splittings become larger. Due to the decreasing population of higher excited states in this series, K^PtFö shows a tri-exponential, K2PtCl6 a bi-exponential and FoPtBr6 a mono-exponential decay. In the latter case the population density of higher excited states relaxes so fast that emission occurs primarily from the lowest excited Γ3(3T1g) level. Phase transitions and emission from chromophores on different sites can also be observed.
Dihydronaphthalenone Carboxylates - Spectral Characteristics and Structure
Authors: Bakalova Sn. , Georgieva A. , Nikolov P. , Stanoeva E.
Published: February 2015

The absorption and luminescence characteristics of a group of newly synthesized methyl esters of 2-alkyl (p-substituted-aryl) -aminomethylene-3,4-dihydro-1(2 H)-naphthalenone-4-carboxylic acids have been investigated. The studied compounds may exist in three tautomeric forms. On the basis of comparison of their electronic spectra to those of similar substances, the observed substituent effect on the position of the UV-VIS absorption bands, the IR spectra and the results of PPP-SCF-CI quantum-chemical calculations it is concluded that the keto tautomer predominates in solution.
Notiz: Report on the Generalized Tanh Method Extended to a Variable-Coefficient Korteweg-de Vries Equation
Authors: Tian Bo , Gao Yi-Tian
Published: February 2015

We briefly report that the generalized tanh method can be extended from the situation with coefficient constants to that with coefficient functions. Soliton-typed solutions for a vari-able-coefficient Korteweg-de Vries equation are thus found. Similar work can be done for the generalized variable-coefficient Kadomtsev-Petviashvili equations.
Research Note on New Similarity Reductions of a Variable-Coefficient Korteweg-de Vries Equation
Authors: Tian Bo
Published: February 2015

For a variable-coefficient Korteweg-de Vries equation we obtain 4 new similarity reductions to the Painleve type equations or the Weierstrass elliptic function equation.
On Some Aspects of an Hg Based EPR Experiment
Authors: Walther Thomas , Fry Edward S.
Published: February 2015

An experimental realization of Bohm's spin-1/2 EPR gedanken-experiment is possible using the spin-1/2 nuclei of the isotope 199 Hg. The dissociation of dimers of the 199 Hg 2 isotopomer, using a spectroscopically selective stimulated Raman process, leads to the generation of an entangled state between the two 199 Hg atoms. The measurement of nuclear spin correlations between the two atoms in this entangled state is achieved by detection of the atoms using a spin state selective two photon excitation-ionization scheme. The experiment will not only close the detector efficiency loophole, but in addition will permit enforcement of the locality condition. Effects of imperfect analyzers will also be discussed.
Fuzzy Transitions from Quantum to Classical Mechanics and New Phenomena of Mesoscopic Objects
Authors: Hsu J. P.
Published: February 2015

A new "phase invariant" equation of motion for both microscopic and macroscopic objects is proposed. It reduces to the probabilistic wave equation for small masses and the deterministic classical equation for large masses. The motions of mesoscopic objects and fuzzy transitions between quantum and classical mechanics are discussed on the basis of the generalized equation. Experimental tests of new predictions are discussed.
Measurement of a Weak Value
Authors: Hulet R. G. , Ritchie N. W. M. , Story J. G.
Published: February 2015

"Weak measurements" are measurements in which the coupling between the measuring device and the observable to be measured is so weak that the eigenvalues of the observable are not resolved. Under certain circumstances the corresponding eigenfunctions can be made to interfere, producing a measurement result which is outside the allowed range of the observable's eigenvalues. We present the first measurement of this so-called "weak value" using an optical experiment. In our experiment, the small displacement between the two orthogonally polarized components of a laser beam passed through a birefringence crystal is measured. We use a numerical simulation to show that this phenomenon may be practical for detecting and amplifying small effects.
Predicting Two Dimensional Hamiltonian Chaos
Authors: Pattanayak Arjendu K. , Schieve William C.
Published: February 2015

We use geometrical analysis to show that the Toda-Brumer-Duff criterion for transition to chaos is a simple application of Jacobi's equation. Further, we propose a new criterion for this transition for two-dimensional hamiltonian systems and summarize the results.
A Principal of Linear Covariance for Quantum Mechanics and Its Consequences Taking one Beyond Symmetry
Authors: Sinanoğlu Oktay
Published: February 2015

A Principle of Linear Covariance is stated which follows from the "superposition principle" of quantum mechanics. Accordingly, quantum mechanical equations should be written in linearly covariant form which makes them look the same under non-unitary as well as unitary transformations. The principle leads to a non-unitary classification of all molecules (and clusters and solids) into distinct equivalence classes giving hitherto unknown relations between isomeric molecules. One also gets kinetic and thermic selection rules for chemical reactions. All these are independent of, and far more general than any unitary or point group symmetries. The invariants found for each class of molecules or clusters allow qualitative electronic deductions and are more generally applicable than symmetry based quantum numbers.
Coherent States and Coordinate-Free Quantization
Authors: Klauder J. R.
Published: February 2015

The usual quantization procedures interpret canonical transformations in an active way linking them with unitary transformations, while the quantization procedure offered by coherent states completely separates classical canonical transformations and unitary operator transformations. By exploiting this property, along with a physically motivated shadow metric, it is seen how to realize the quantization process in as coordinate-free a form as holds in classical mechanics.
W-Algebras
Authors: 'Raifeartaigh L.
Published: February 2015

W-algebras are defined as polynomial extensions of the Virasoro algebra by primary fields, and they occur in a natural manner in the context of two-dimensional integrable systems, notably in the KdV and Toda systems. Their occurrence in those theories can be traced to their being the residual symmetry algebras when certain first-class constraints are placed on Kac-Moody algebras. In particular, their occurrence in 2-dimensional Toda theories is explained by the fact that the Toda theories can be regarded as constrained Wess-Zumino-Novikov-Witten (WZNW) theories. The general form of such first-class constraint for WZNW theories is investigated, and is shown to lead to a wider class of two-dimensional integrable systems, all of which have W-algebras as symmetry algebras.
Gravitation Theory in Path Space
Authors: Teitelboim Claudio
Published: February 2015

A formulation of gravitation theory originally proposed by Mandelstam is re-examined. The idea is to avoid the use of coordinates while staying in the continuum. This is accomplished by regarding a point as the end of a path. The theory is then formulated in the space of all paths. The analysis relies on the properties of path deformations. These deformations play the role of gauge transformations in path space. Their algebra is established. It closes if and only if the defining conditions of a riemannian geometry hold (Bianchi identity and vanishing of the antisymmetric part of the Riemann tensor in three of its indices). Two problems faced by Mandelstam are solved: (i) An explicit formula is given which establishes when two neighboring paths end at the same point, (ii) An action principle is given, in terms of a functional integral over path space. It is also indicated how to reconstruct the metric from the curvature through gauge fixing in path space. Brief comments are offered on the possibility of developing an invariant description of loops regarded as boundaries of two-dimensional surfaces.
A Conformal Field Theory of Extrinsic Geometry of 2-d Surfaces
Authors: Viswanathan K.S. , Parthasarathy R.
Published: February 2015

In the description of the extrinsic geometry of the string world sheet regarded as a conformal immersion of a 2-d surface in R3 it was previously shown that, restricting to surfaces with h √ g = 1, where h is the mean scalar curvature and g is the determinant of the induced metric on the surface, leads to Virasaro symmetry. An explicit form of the effective action on such surfaces is constructed in this article, which is the extrinsic curvature analog of the WZNW action. This action turns our to be the gauge invariant combination of the actions encountered in 2-d intrinsic gravity theory in light-cone gauge and the geometric action appearing in the quantization of the Virasaro group. This action, besides exhibiting Virasaro symmetry in z-sector, has SL (2, C) conserved currents in the z̅-sector. This allows us to quantize this theory in the z̅-sector along the lines of the WZNW model. The quantum theory on h √ g = 1 surfaces in R3 is shown to be in the same universality class as the intrinsic 2-d gravity theory.
Energy Gain, Stability, and Bunching in Gas-Loaded Hermite-Gaussian Laser Linac
Authors: Bochove E. J. , Moore G. T. , Scully M. O.
Published: February 2015

Gas-loaded Hermite-Gaussian laser linacs yield greater gain and interaction lengths then vacuum linacs, however, optical beam and drift tube damage are not adequately alleviated in uniformly loaded devices. These problems can be resolved if the loading is graded so as to accommodate the phase velocity variation of the laser beam.
Squeezing of Light within the Framework of Population Theoretic Approach
Authors: Srinivasan S. K.
Published: February 2015

A multiphase approach for the population model of photons is proposed and it is shown that number squeezed coherent light as well as thermal light can be accomodated. It is also shown that the multiphase approach is a very natural way of describing non-Markov nature of the evolution of the density matrix.
Laser-Phase-Noise-Induced Stochastic-Resonance Fluorescence
Authors: Su Chang , Rangwala A.A. , Wódkiewicz K.
Published: February 2015

Stochastic fluctuations of coherent and incoherent components of the resonance fluorescence intensity induced by Wiener-Levy laser phase noise are investigated. Statistical properties of the atomic dipole moment and stochastic Mollow spectra of atomic dipole fluctuations for different values of the laser linewidth and Rabi frequency are calculated. It is shown that these spectra exhibit a triplet structure which is purely classical and entirely laser-noise dependent.
High Resolution Subwavelength Inspection Method for Measuring the Uniformity of Conducting Films
Authors: Torti Russell G. , Couchman James C.
Published: February 2015

A microwave adapter was fitted to a wax filled reducing wedge in order to transmit 8-12 GHz microwaves through a sub-wavelength rectangular opening. The configuration produced a 70 dB dynamic range and was found suitable for high resolution inspection of 1 to 10,000 ohm per square conducting films. Network analyzer measurements on 12 conducting films that were reported to be 5 to 1500 ohms per square are compared to the reported values and reconciled with electromagnetic theory.
The Structure of QCD Vacuum and Related Topics
Authors: Bose S. K.
Published: February 2015

The structure of the vacuum and the attendant state-space for models with a spontaneous breakdown of a global U(1) symmetry is reviewed. QCD is examined in the light of this analysis. Certain commonly held views in QCD are found to need revision and rethinking.
How Can We Find the Exotics?
Authors: Bhamathi G.
Published: February 2015

A search is proposed for dibaryonic systems with non-zero charm and beauty quantum numbers which are more suitable for unambiguous identification. An estimate of the production cross sections for the dibaryonic systems Hc , Hb and Hbs is presented.
Relativistic Hamiltonian Model for Higgs Resonance
Authors: Chiu Charles B. , Sudarshan E . C . G . , Bhamathi G.
Published: February 2015

We construct a relativistic Hamiltonian model for Higgs resonance. Resonance trajectories are studied as a function of the parameters of the model. The possibility of a narrow width Higgs resonance in 1 TeV region cannot be ruled out from general considerations. Our model may serve as a phenomenological guide in the search for Higgs resonance.
CP Violation
Authors: Gilman Frederick J.
Published: February 2015

The phenomenon of CP violation is examined, and predictions for its manifestations based on the three-generation Standard Model are reviewed. Applications to the K and B meson systems are emphasized.
Production of Tauonic Uranium in e+ -e- Machines
Authors: Morley P. D.
Published: February 2015

I discuss the production of tauonic uranium in e+ -e- machines. A suggested experimental arrangement is given which allows for future machine improvement. To obtain the energy levels to within 1% accuracy, the Dirac equation is solved using a radial uranium charge distribution. Finally, weak t capture P + τ ￫ N + υτ in uranium is calculated.
SU (2/1) as a Chiral Supersymmetry
Authors: Ne'eman Yuval
Published: February 2015

The Weinberg-Salam model is embedded in SU (2/1), thereby considerably reducing the arbitrariness in SU(2) and U(1) assignments for leptons and quarks. The grading of the matter fields corresponds to their chirality. The action of the odd generators of a superalgebra usually involves a change in the statistics of the states, in the representation carrier-space. We explain the interplay between chiralities and statistics.
Old Wine in New Bottles - Mass Spectra, Bootstrap and Hierarchy
Authors: Nambu Y.
Published: February 2015

A brief review is given of the problem of masses and mass spectra, and of an attempt to seek their dynamical origins.
A Brief Introduction to the Strong CP Problem
Authors: Wu Dan-di
Published: February 2015

The present status of the strong CP problem is briefly reviewed in a heuristic way. A crisis in EDMN calculation is explained. The equation of vacuum alignment obtained by the author and collaborators last year put a constraint on strong CP parameters. Thus the strong CP will be forced to vanish in one of the three scenarios characterized respectively by axion, zero quark mass and vanishing quark condensate.
On Hide's Magnetic Analogue of Ertel's Vorticity Theorem
Authors: Schröder W. , Treder H.-J.
Published: February 2015

The relativistic formulation of Hide's "magnetic analogue" of Ertel's potential vorticity theorem is Dirac's "new classical theory of electrons".
PVT Measurements on 4-n-Pentyl-4´-Cyano-Biphenyl (5CB) and trans-4-(4´-Octyl-Cyclohexyl)-Benzonitrile (8PCH) up to 300 MPa
Authors: Sandmann M. , Hamann F. , Würflinger A.
Published: February 2015

Specific volumes are presented for 4-n-pentyl-4´-cyanobiphenyl (5CB) and trans-4-(4´-octyl-cyclo-hexyl)-benzonitrile (8PCH) for temperatures between 300 and 370 K up to 300 MPa. The p,Vm ,T data were determined for the liquid crystalline and isotropic phases, and partly also for the solid phase adjacent to the melting curve. Stable and metastable crystal phases can be distinguished. The density and melting temperature of the metastable form are lower than for the stable one. Volume and enthalpy changes accompanying the phase transitions are reported as well. The p,Vm ,T data allow to calculate the entropy change for a hypothetical transition at constant volume. The molar volumes along the nematic-isotropic phase transition TNI (p) allow to determine the molecular field parameter γ = ∂In TNI /∂ In VNI.
Second Virial Coefficients and Transport Properties of Hexafluoride Gases from an Improved Intermolecular Potential
Authors: Coroiu Ilioara , Demco D. E.
Published: February 2015

Second virial coefficients and a large number of Chapman-Cowling collision integrals were calculated for gases obeying an improved intermolecular potential proposed by Aziz et al. [J. Chem. Phys. 94, 1034 (1991)]. The results are tabulated for a large reduced temperature range, kT/ε from 0.1 to 100. The treatment was entirely classical, and no corrections for quantum effects were made. The higher approximations to the transport coefficients were also calculated and tabulated for the same temperature range. These results should be applicable to characterize the bulk properties of various spherical molecules, especially to predict gaseous transport properties. Evaluation of the potential parameters for uranium hexafluoride, together with fitting to second virial coefficient, viscosity, thermal conductivity and self-diffusion data are also presented. This potential appears to have the best overall predictive ability for gaseous hexafluoride data.
Proton Spin-lattice Relaxation in Amorphous States of Organic Molecular Solids
Authors: Myaing M. T. , Šekarić L. , Beckmann P. A.
Published: February 2015

We have measured the temperature dependence of the proton spin-lattice relaxation rate R at 8.50 and 22.5 MHz in solid 1,3,5-tri-ethyl-benzene and solid 1,2,4-tri-ethyl-benzene. Analysis of the data strongly suggests that we are studying amorphous states in these slowly solidified organic solids (that are liquids at room temperature). The ethyl groups are static on the Larmor frequency time-scale. There are no simple-model interpretations of the data, but a reasonable model for the dominantly-occurring amorphous state data observed with 1,3,5-tri-ethyl-benzene suggests that two of the three methyl groups are reorienting and the third is static on the proton Larmor frequency time scale. The same approach for the two amorphous states observed in 1,2,4-tri-ethyl-benzene suggests that all three methyl groups are reorienting in one state and that three of the six methyl groups in each pair of molecules are turned off in a second state. We discuss that, whereas specific dynamical statements are model dependent, the proton spin relaxation technique does make some general qualitative statements about the mesostructure of the solid.
Spectral-Interferometry Measurements of Copper Atom Concentration in a Segmented Hollow Cathode Discharge
Authors: Szalai L. , Ulbel M. , Neger T. , Pretzler G. , Donkó Z. , Rózsa K. , Tobin R. C.
Published: February 2015

We report spectral-interferometry measurements of the concentration and the spatial distribution of copper vapor in a high voltage, segmented hollow cathode discharge, which is an efficient source for laser light generation. The concentration of sputtered copper atoms was found to be in the order of 1014 cm-3 at currents of 0.6-1.0 A in a 5 cm long, 4 mm bore diameter discharge tube, operating in argon buffer gas. At high pressures and relatively low current densities the sputtered metal concentration forms two maxima near the cathode surface. With increasing current and decreasing pressure these two maxima move towards the center of the discharge. This result may account for the fact that at certain discharge parameters the segmented hollow cathode lasers operate in higher order transverse modes near the threshold. The measurements of copper vapor concentration show increased sputtering compared to conventional hollow cathodes, which is considered to be one of the reasons for segmented hollow cathode metal ion lasers being more efficient.
Ultrasonic Studies of Ferroelectric Phase Transition in Gly-H3PO3 Crystals
Authors: Furtak J. , Czapla Z. , Kityk A.V.
Published: February 2015

The temperature behaviour of the longitudinal and transverse ultrasound wave velocities and attenuation in the region of the ferroelectric phase transition (Tc = 225 K) of the glycine phosphite (Gly-H3PO3) crystals is studied. The obtained results are considered within the framework of phenomenological theory.
NMR Study of Cation Motion in Guanidinium Iodoplumbates
Authors: Grottel M. , Szafrański M. , Pająk Z.
Published: February 2015

Proton NMR second moments and spin-lattice relaxation times of polycrystalline C(NH2)3PbI3 and [C(NH2)3]2PbI4 were studied in a wide temperature range. The order-disorder character of the existing solid-solid phase transitions was confirmed and for tetraiodoplumbate a new phase transition at 170 K was discovered. For both compounds a dynamical inequivalence and unusual high mobility of the guanidinium cations were revealed. For the reorientations discovered (NH2 group flipping, C3 in-plane reorientation and a tumbling) the activation parameters were determined.
The Use of Parameter-Free Correlation Functions in Green's Function Monte Carlo Simulations of Small Electronic Systems
Authors: Mecke C. , Seelig F. F.
Published: February 2015

Using an old formulation for correlation functions with correct cusp-behaviour, the Schrödinger equation transforms to a new differential equation which provides a very simple expression for the local electronic energy with limited range. This, together with the simplicity of the formulation promises a high performance in Green's function Monte Carlo (GFMC) simulations of small electronic systems. The behaviour of the local energy is studied on a few simple examples because the variance of this function determines the quality of the results in the GFMC methods. Calculations for one-and two-electron systems are presented and compared with results from well-known functions. The form of the function is then extended to systems with more than two electrons. Results for the Be atom are given and the extension to larger electronic systems is discussed.
Hydrogen Isotope Fractionation in Aqueous Alkali Halide Solutions
Authors: Kakiuchi Masahisa
Published: February 2015

The D/H ratios of hydrogen gas in equilibrium with aqueous alkali halide solutions were deter-mined at 25 °C, using a hydrophobic platinum catalyst. The hydrogen isotope effect between the solution and pure water changes linearly with the molality of the solution at low concentrations, but deviates from this linearity at higher concentration for all alkali halide solutions. The magnitude of the hydrogen isotope effect is in the order; Kl > Nal > KBr > CsCl ≧ NaBr > KCl > NaCl > LiCl, at concentrations up to a molality of 4 m. The sign and trend of the hydrogen isotope effect is different from that of oxygen. In aqueous alkali halide solutions, the hydrogen isotope effect is influenced by both the cation and the anion species, while the oxygen isotope effect is mainly caused by the cation species. This suggests that the mechanism of hydrogen isotope fractionation between the water molecules in the hydration spheres and the free water molecules differs from the mechanism of the oxygen isotope fractionation. The hydrogen and oxygen isotope effects for alkali halides, except LiCl and NaCl, may be influenced by changes in energy of the hydrogen bonding in free water molecules.
Boron Isotope Effect in Liquid Chromatography with Boron-specific Resins as Packing Material
Authors: Oi Takao , Takeuchi Hirotsugu , Sakurai Akiko , Taguchi Yoshifumi , Hosoe Morikazu
Published: February 2015

Boron isotope separation by liquid chromatography using boron specific resins with N-methyl glucamine as the functional group was performed. The single-stage separation factor, S, is generally dependent on the resin in the sequence S (free base form resin) > S (F- form resin) >S (Cl- form resin) ≧S (Br- form resin) for given experimental conditions. This sequence is the same as that of the pH value expected in the resin phase and reasonably understandable by assuming in addition to the predominant four-coordinate species a three-coordinate boron species in the resin phase whose relative abundance increases with decreasing pH. Supporting evidence for three-coordinate species was obtained by 1: B NMR measurements of boric acid-glycerol and boric acid-1,3-propane-diol solutions.
Cluster Formation in a Concentrated Lithium-Liquid Ammonia Solution. A Monte Carlo Study
Authors: Hannongbua S. , Kokpol S. , Gurskii Z. , Heinzinger K.
Published: February 2015

Results of a Monte Carlo study of a lithium-liquid ammonia solution at 240 K are reported. The basic cube contained 135 Li+ and 1025 NH3 . With an experimental density of 0.554 g/cm3 a side-length of 37.89 Å resulted. The pseudopotential theory is employed, which permits the exclusion of the electrons from an explicit consideration. The structure of the solution is described by various site-site radial distribution functions. The six ammonia molecules in the first solvation shell of the lithium ion are arranged octahedrally. Clusters are formed which consist almost exclusively of two solvated Li+ which have simultaneously either one ammonia molecule or an octahedral edge or an octahedral plane in common. About one third of the ammonia molecules belong to the bulk phase.
Notiz: An Explanation of the Paradox Underlying the Trouton-Hildebrand-Everett Rule
Authors: Rooney J. J.
Published: February 2015

The Trouton-Hildebrand-Everett rule, which is a refinement of Trouton's rule, requires that the so-called molar liquid free volume, V1
0 in the expression ΔSb
0 = Rln(Vg
0 / V1
0) for the entropy of vapourization of molecular liquids is a constant with a volume of 1.5 cm, whereas Vg
0, the corresponding vapour free volume, is directly dependent on the value of the boiling point, Tb . This paradox is resolved using a statistical mechanical rationale for ideal systems which shows that V1
0 is in reality N times a molecular volume derived from a characteristic distance in the liquid-vapour transition state. This distance is the same for all ideal molecular liquids.
Effect of Substituents on the Viscosity Dependence of Fluorescence and on the S1 - T1 Energy Gap of Donor-Acceptor Substituted Trans-Stilbenes
Authors: Wilhelm Hans E. , Gebert Horst , Regenstein Wolfgang
Published: February 2015

The dependence of fluorescence quantum yields and S1-lifetimes of donor-acceptor substituted trans-stilbenes on temperature was measured in the temperature range from 298 to 100 K, using solutions of stilbenes in 3-methylpentane (3-MP). Measurements of fluorescence and phosphorescence spectra show that the triplet energy is almost independent of the acceptor. The S1-energy and the S1-T1 energy gap decrease with increasing acceptor strength. For all compounds intersystem crossing (ISC) S1 → T1, is negligible
Electric and Magnetic Potentials of Uniformly Accelerated Charge Distributions
Authors: Hillion Pierre
Published: February 2015

Jefimenko gave recently [1] new expressions for the electric and magnetic potentials of uniformly moving, time-independent charge distributions. We discuss these potentials for uniformly accelerated distributions. As Jefimenko did. we implement two procedures either converting directly retarded into present position integrals or using relativistic transformations for a stationary charge in an instantaneous comoving inertial frame (Frenet-Serret tetrad). We discuss why, at the difference of what happens for uniform motions [1], both procedures provide different expressions for potentials.
EPR Studies of VO2+ in Ba(ClO4) 2 ・3H2O Single Crystals
Authors: Yavuz Metin , Kalkan Hüseyin , Bulut Ahmet , Atalay Şehriman , Öztekin Emin
Published: February 2015

The results of an electron paramagnetic resonance (EPR) study of vanadyl ion VO2+ doped in single crystals of Ba(ClO4)2 - 3 H2O are reported. The spectra indicated the presence of two substitutional and interstitial sites depending on the orientation. The spin-Hamiltonian parameters were determined from single crystal and powder EPR data. These parameters were found to be axial symmetric for the powder sample, whereas they showed deviations from axial symmetry for the single crystal
Structural Study of Poly-Molybdate Ions in Acid Mo-Ni Aqueous Solutions
Authors: Shinoda Kozo , Matsubara Eiichiro , Saito Masatoshi , Waseda Yoshio , Hirato Tetsuji , Awakura Yasuhiro
Published: February 2015

The atomic structure of poly-molybdate ions formed in acid Ni-Mo aqueous solutions has been determined by applying anomalous X-ray scattering (AXS) and EXAFS methods. In a solution containing only molybdenum ions, we found only a poly-molybdate ion consisting of seven edgesharing MoO6 octahedra. In a solution containing both Mo and Ni ions, there exists another polymolybdate ion consisting of 6 edge-sharing MoO6 surrounding an Ni ion. The total coordination number of Mo and Ni ions around a molybdenum ion is reduced by half when introducing citric ions into the Ni and Mo solution. This indicates that the large poly-molybdate ion is decomposed to smaller molybdate ions when forming citric complexes. Since molybdenum-nickel alloys can not be electrodeposited from solutions without citric ions, we propose a view that the structural change of the poly-molybdate ions in the solutions is closely related with the mechanism of induced codeposition of molybdenum and nickel alloy. The results of small-angle X-ray scattering (SAXS) measurements also support this conclusion.
Polygonal Systems Including the Corannulene and Coronene Homologs: Novel Applications of Pólya's Theorem
Authors: Cyvina S. J. , Cyvin B. N. , Brunvoll J. , Gutman I. , Rong-si Chen , El-Basil S. , Fuji Zhang
Published: February 2015

A system of Class Qq is a polygonal system consisting of one central q-gon circumscribed by q other polygons, which may possess different sizes. As chemical graphs, these systems represent polycyclic conjugated hydrocarbons, which include homologous series of C20H10 corannulene and C24H12 coronene along with many other molecules of interest in organic chemistry. The problem of isomer enumeration for the Qq systems is solved completely in terms of generating functions by means of Póya's theorem
Boron Nuclear Quadrupole Coupling in BF(OH)2
Authors: Storm V. , Dreizler H.
Published: February 2015

We investigated the nuclear quadrupole coupling of the 11B and 10B nuclei in fluorodihydroxy borane, BF(OH)2. An analysis of the hyperfine splittings resulted in the coupling constants %aa = -1.414(11) MHz, %bb = - 1.206(11) MHz, %cc = 2.620(11) MHz for 11B and %aa = -2.872(67) MHz, y M = -2.525(69) MHz, %cc = 5.397(69) MHz for 10B. From these constants the ratio r of the quadrupole moments r = Q(10B)/Q(11B) = 2.051 (44) could be derived and compared to data taken from the literature
Exchange Currents in Baryons
Authors: Buchmann Alfons J
Published: February 2015

This paper reviews calculations of the electromagnetic properties of baryons using the constituent quark model. We start with a short discussion of spontaneous chiral symmetry breaking, which is essential in understanding the transition from QCD to the constituent quark model. We then discuss a chiral version of the constituent quark model, which simulates the symmetries and dynamical content of the underlying field theory in terms of gluon, pion and sigma exchange between constituent quarks. We show that the electromagnetic current charge and current operators, usually approximated by one-body operators (impulse approximation), must be supplemented by appropriate two-body terms (exchange currents). The latter represent the gluon and pion exchange degrees of freedom in the electromagnetic current operator. These exchange currents must be included for reasons of completeness and consistency. Most importantly, however, they are needed in order for the electromagnetic current to be conserved. We also study the effect of scalar exchange currents connected with the confinement and sigma exchange potentials. By including these twobody exchange currents we go beyond the single-quark impulse approximation, which has mainly been used up to now. The inclusion of gluon- pion-, and scalar-exchange currents in the quark potential model is the new point of the present work. We show that for some observables, such as the magnetic moments, charge, and magnetic radii of the proton and charged Δ (1232) states, exchange currents contribute at the level of some 10%. The same holds true for the magnetic moments of the entire baryon octet, with the exception of the Ξ- magnetic moment. On the other hand, the neutron charge radius, the quadrupole moments of the Δ, and the N → Δ transition quadrupole moment, are dominated by pion and gluon exchange contributions to the charge density operator. The inclusion of the pion and gluon exchange currents leads to a neutron charge radius of the correct size and sign. Based on the gluon and pion exchange current diagrams, we derive parameter-free relations between the neutron charge radius, the quadrupole moment of the Δ, and the N → Δ transition quadrupole moment. Neglecting configuration mixing, we find that the neutron charge radius and the N → Δ transition quadrupole moment are simply related as QN→Δ = r2
n√2. The implications of Siegert's theorem for the calculation of the E2 form factor in the N → Δ transition are studied. Finally, we discuss the axial coupling constant of the nucleon. We show that the inclusion of axial pair exchange currents does not significantly alter the NRQM prediction.
Calculation of the NMR Second Moment for Solid Benzene with Rotation and Diffusion of Molecules - Numerical Approach
Authors: Goc Roman
Published: February 2015

Numerical calculations of the NMR second moment in case of rotation and diffusion of molecules were performed. As an example computer simulations of molecular reorientation and self-diffusion in solid benzene have been performed. For each model and rate of motion the Van Vleck's second moment of the proton NMR absorption spectrum was calculated, and these values were compared with experimental data. It is concluded that restricted self-diffusion must be implied in order to obtain better agreement between calculated and experimental NMR second moments. The temperature at which self-diffusion was detected through NMR line-width narrowing was found to be about 120 K, nearly 80 K less than the temperature at which the self-diffusion was detected by T 1ρ relaxation measurements.
A Weak Field EPR Study of TANOL in Water and Water-Oil Using Dynamic Nuclear Polarization
Authors: Horasan N. , Sünnetçioğlu M. M. , Sungur R. , Bingöl G.
Published: February 2015

Solutions of 4-hydroxy-TEMPO(TANOL) in water and water-soyabean oil were investigated in the concentration range 0.1 mM-10mM. Dynamic nuclear polarization (DNP) and electronic relaxation time T1e measurements were performed at each well resolved hyperfine line. In the TANOL/water-soyabean oil solutions, the effect of the presence of soyabean oil was an increase in the measured relaxation rates and a decrease in the observed enhancements. In addition, the observed enhancements diminished in time. For all of the samples, the relaxation rates decreased as the frequency of the transition increased.
Differential Thermal Analysis under High Pressure on 6-TPEB
Authors: Ernst C. , Schneider G.M. , Würflinger A. , Jadżyn J. , Dąbrowskib R.
Published: February 2015

The high pressure phase behaviour of a new liquid crystal, belonging to the series l-[4-«-alkylbiphenyl]-2-[4-isothio-cyanato-phenyl] ethane (nTPEB), n = 6, has been studied with differential thermal analysis. The pressure dependence of the phase transitions has been determined up to 300 MPa. No pressure-induced or pressure-limited phases are observed in this pressure range, the phase behaviour, however, depends on the thermal treatment. Enthalpy and volume changes accompanying the phase transitions have been calculated

using the Clausius-Clapeyron equation.
Peculiarities of the 35Cl and 79Br NQR Spectra of Chalcogenhalide Complexes of Some Transition Metals
Authors: Fokina Z.A. , Kolesnichenko V.L. , Pekhnyo V.l. , Volkov S.V.
Published: February 2015

The peculiarities of the 35Cl, 79Br NQR spectra of the chalcogenhalide complexes are explained in terms of intraspheric effect of ligands, formation of secondary intra-and intermolecular bonds, and electronic structure of metal atom. In the 35Cl spectra of [TeCl3 ]2[OsCl6 ] 1, [SeCl3]2[OsCl6]2 and [TeCl3]2 [ReCl6 ]3 the 7-10% increase in frequency in the low-frequency multiplet are accounted for by the disturbance of the pHal-dM π-interaction due to the formation of the peripheral coordination polyhedra [SeCl6 ] and [TeCl6 ]. The peculiarities of the 35 Cl and 79 Br spectra of [MoS2 Cl3 (SeCl2)]2 4, [MoS2 Br3 (SeCl2)]2 5, [WS2Cl3 (SeCl2)]2 6 and [WS2 Br3 (SeBr 2)] 2 7 are attributed to the disturbance of the pHal-dM π-interaction under the influence of the coordination of the SeCl2 and SeBr2 ligands and formation of secondary intramolecular bonds. For [RhCl3 (SeCl2)2]2 8, [IrCl3 (SeCl2)2]2 9 and [SCl3 ][IrCl4 (SCl2)2]10, the appearance of frequencies at 25 MHz in low-frequency triplets is attributed to the intraspheric effect of weak donors-neutral SCl2 and SeCl2 molecules; the frequencies at 18 MHz are assigned to bridging chlorine atoms. This assignment was confirmed by the dimeric structure, which was established by an X-ray structure analysis.
On the Supposed Surrealism of Bohmian Mechanics
Authors: Becker Lon
Published: February 2015

In a recent paper, Englert et al. reject Bohm's reinterpretation of quantum mechanics as "surrealistic." Responses to this by Dewdney et al. and Durr et al. have generally missed the point of this somewhat strange characterization of the interpretation.

In this paper I explain the experiment which is supposed to illustrate the surrealism. I argue that what is really being objected to is the non-locality of the interpretation. While this is an undesirable feature of Bohm's interpretation, it is not a feature of which the standard interpretation gives a more satisfactory account.
Investigation of the Reaction between Fe2O3 and Al Accomplished by Ball Milling and Self-Propagating High-Temperature Techniques
Authors: Cao Giacomo , Concas Giorgio , Corrias Anna , Orru' Roberto , Paschina Giorgio , Simoncini Barbara , Spano Giorgio
Published: February 2015

In this work we investigate the mechanism of product formation of the aluminothermic reaction of Fe2O3 in the presence of Al2O3 using Ball Milling and Self-propagating High-temperature techniques.

Results obtained by experiments under either argon or air atmosphere are analysed by X-ray diffraction and Mössbauer spectroscopy, together with microstructure observations. It is shown that ball milling products are strongly affected by the kind of atmosphere, while self-propagating high-temperature ones are only weakly influenced. Reaction mechanisms taking place in these cases are proposed.

While ball milling involves only solid state reactions, the formation of a melt occurs under self-propagating high-temperature conditions.
Isolated versus Condensed Anion Structure III: The Influence of the Cations 1,3-propanediammonium, 1,4-butanediammonium, /n-propylammonium, /n-butylammonium and /n-pentylammonium on Structures and Phase Transitions of ZnBr4
2- Salts. A81 Br NQR and X-ray Structure Analysis
Authors: Ishihara Hideta , Dou Shi-qi , Horiuchi Keizo , Paulus Helmut , Fuess Hartmut , Weiss Alarich
Published: February 2015

The influence of the cations on the condensation of the anions in the salts (A´)Zn(II) Br4 and (A) 2 Zn(II)Br4 is studied by 81Br NQR and X-ray crystal structure analysis. (A´)Zn(II)Br4 (A´ = [H3N(CH2)3NH3]2+) (1) shows a phase transition at 474 K. The phase II of (1) crystallizes with isolated [ZnBr4]2- tetrahedra: monoclinic P21 /n, Z = 4, a = 1108.4 (5), b = 1096.8 (2), c = 1118.5 (6) pm, and β= 117.07(4)° at 296 K. A quartet was observed in the 81Br NQR spectrum of phase II: 61.634,58062, 56.675, and 53.673 MHz (77K); 59.193, 57.448, 56.015, and 52.515 MHz (301 K).(A)2 ZnBr4 (A = [n-H3C(CH2)2NH3 ]+ (2) and [n-H3C(CH2)3NH3 ]+ (3)) also show structures with isolated [ZnBr4]2- tetrahedra. The compound (2) crystallizes with P21/c, Z = 4, a = 771.8(3), b = 1061.9(4), c = 2054.2 (7) pm, and β = 106.75(1)° at 291 K. The compound (3) crystallizes with P21/c, Z = 4, a = 768.9(4), b = 2229.6(10), c = 1071.6(5) pm, and β = 91.70(3)° at 295 K. 81Br NQR and DSC measurements on [H3N(CH2)4 NH3]ZnBr4 (4), and [n-H3 C(CH2)4NH3]2ZnBr4 (5) were also performed. The compound (4) shows several phase transitions at 349 K and higher temperatures, and a quartet in the 81r NQR spectrum could be observed between 77 and 330 K: 65.992,65.544, 59.900, and 50.162 MHz (77 K); 63.787, 62.963, 59.928, and 50.364 MHz (320 K). The compound (5) shows also a phase transition at 244 K, and a quartet of 81Br lines could be observed in the NQR spectrum between 77 and 244 K: 61.279, 58.933, 57.869, and 56.485 MHz (77 K); 59.712, 56.936, 57.409, and 54.793 MHz (240 K). The various influences of the cations, such as size and hydrogen bonds on the condensation of [MX4]2-(M = Zn, Cd; X = C1, Br) are discussed.
Theoretical Determination of the Mass of a Roton
Authors: Bohaty Sean
Published: February 2015

For 56 years, researchers have sought, with varied success, to determine the mass of a roton. However, with the recent emergence of the author's theory of superfluid 4He, the time may soon be at hand when the roton's mass is determined unequivocally. This letter reports the first quantitative results of the new theory of helium II. Using data from a neutron scattering experiment, the mass of a roton was calculated. It was found that the roton mass is 2.12 x 10 -27 kg or approximately 0.32 mHe , where mHe is the mass of a helium atom.
Notiz: Mittlere Schwingungsamplituden der "Onium" Kationen H3O+ , H3S+ und H3 Se+
Authors: Baran E.J.
Published: February 2015

Mean Amplitudes of Vibration of the "Onium" Cations H3O+, H3S+ and H3Se+ Mean amplitudes of vibration of H3O+, H3S+ and H3Se+ have been calculated from spectroscopic data in a wide temperature range. The results are briefly discussed in comparison with data of related species.
Frequency Clustering in a Chain of Weakly Coupled Oscillators
Authors: Kirner Thomas , Rössler Otto E.
Published: February 2015

A numerical simulation of a chain of diffusively coupled nonlinear oscillators with a linear parameter gradient exhibits clusters of frequencies. The intention was to investigate the frequency-gradient in the stimulus conduction system of the heart. The phenomenon generalizes earlier findings on “frequency plateaus” described in the 1960's by Nicholas Diamant as a model of small-intestine transport. This “waxing and waining” phenomenon is a version of chaos. Thus, subtle chaos in the heart and waxing and waining type chaos in the intestine may be related.
Whispering Gallery Orbits in the Bunimovich Stadium
Authors: Kruelle C. A. , Kittel A. , Peinke J. , Richte R.
Published: February 2015

A new visualization method is found for investigating the complex ray dynamics of whispering gallery orbits inside the Bunimovich stadium. Regarding the whispering gallery as mirror cabinet, a fractal system of virtual images of the mirror walls is found which reflects the sensitive dependence of the dynamic behavior on the initial conditions.
A New Approach to Characterize Disordered Structures
Authors: Peinke J. , Friedrich R. , Naert A.
Published: February 2015

A new application of the theory of Markov processes to the characterization of fractal scaling behavior is presented. We show under which condition distinct stochastic processes of a cascade lead to multifractal scaling behavior. We apply our method to the analysis of the statistical properties of the energy in turbulent fluid flow.