bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Calculation of the NMR Second Moment for Solid Benzene with Rotation and Diffusion of Molecules - Numerical Approach
Authors: Goc Roman 
Published: February 2015

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Frequency Clustering in a Chain of Weakly Coupled Oscillators
Authors: Kirner Thomas , Rössler Otto E. 
Published: February 2015

Abstract
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

Abstract
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

Abstract
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.
Micro Relativity
Authors: Rössler Otto E. , Diebner Hans H. , Pabst Werner 
Published: February 2015

Abstract
A new synthesis based on microscopic classical thinking is attempted in the spirit of the molecular-dynamics-simulation (MDS) paradigm. Leibniz’s idea that joint scale transformations cancel out is invoked. Boltzmann discovered that a time reversal in the whole universe is undetectable from the inside. As a corollary, objective micro time reversals occur in the interface between a subsystem and the rest of the universe, whenever the former undergoes a time reversal. This is shown to occur in a generic class of Hamiltonian systems. The “microinterface” arrived at generalizes the macro frame of relativity to the micro realm. Micro relativity comprises Bohr’s idea of an observer-relative complementarity and Everett’s idea of an observer-relative state. As in relativity proper, a multiplicity of worlds (cuts) exist. For the inhabitants of an artificial MDS universe, therefore a radically new option is available: world change technology.
Computer Simulation of the Order-Disorder Transition in Ammonium Chloride
Authors: Goc Roman , Wąsicki Jan W. 
Published: February 2015

Abstract
The phase transition at Tc = 243 K in ammonium chloride is well established to be of the order-disorder type. The ammonium chloride has a CsCl-type cubic structure with hydrogen atoms pointing toward four of the eight chloride ions at the corners of the unit cell. This means that there are two possible orientations of ammonium tetrahedron; a and b. In the ordered phase below the Tc temperature all ammonium ions have the same, let it be a, orientation. Above the Tc temperature ions are randomly distributed among the two possible orientations a and b. An attempt was made to correlate such structural transition with the second moment of the proton NMR absorption line. This approach was chosen because the second moment is the parameter of the NMR line for which the exact theoretical formula exist, and which is mainly a function of the structure and the reorien-tational state of the studied material. It was found that the NMR second moments calculated for the described above model of the structural transition properly reflect the changes of the experimental NMR second moments measured at temperatures below and above this transition.
35Cl NQR Studies of Bismuth Trichloride
Authors: Babu P. K. , Ramakrishna J. 
Published: February 2015

Abstract
The temperature dependence of the 35Cl nuclear quadrupole resonance (NQR) frequency and spin lattice relaxation time (T1) are studied in crystalline BiCl3 , in the range 40-300 K. The positive temperature coefficient observed for one of the 35Cl resonances is explained in terms of the strong intermolecular interactions that exist in this compound. Variation of with temperature is found to be similar at the chemically inequivalent halogen sites. Semiclassical descriptions based on torsional oscillator dynamics are found to be inadequate for explaining the spin lattice relaxation. T1 (T) data follow an AT2 + BT3 type behaviour, indicating that the anharmonic nature of the lattice vibrations plays a significant role in determining the temperature dependence of T1 at high temperatures.
Charge Transport and Relaxation in Triglycine Sulphate (TGS)
Authors: Osak W. 
Published: February 2015

Abstract
Charging currents, J-V characteristics and electron conductivity have been measured in triglycine sulphate along three crystallographic directions: a, b and c. The measurements have been taken in a wide temperature range between −196°C and 80 °C. It is found that the charging currents have short relaxation times in the directions: a and c and a long relaxation time along the ferroelec-tric b axis. The J-V characteristics in the direction of the a and c axes have the shapes characteristic for linear dielectrics with space charge limited currents. The J-V characteristic for the b axis depends on the temperature: In the region of the phase transition the Fridkin-Kreher formula (J ∝ V4/3) is satisfied; for low temperatures characteristic agrees with SCLC theory for linear dielectrics with Gaussian traps energy distribution. The d.c. conductivity along the c axis is much higher than along the a and b axes. In the investigated temperature range, the electrical conductivity has an activation character. For −100 °C < T < −193 °C there is: σ ∝ (1/T) exp (− E/kT) . The activation energy depends both on the crystallographic direction and on the temperature-range. For low temperatures, T < −100 °C, the activation energies are very small (of the order of a few hundreds eV).
An Exact and Simple Approach to log-log Plots for Defect and Ionic Equilibria
Authors: Spinolo Giorgio , Anselmi-Tamburini Umberto , Ghigna Paolo 
Published: February 2015

Abstract
An alternative approach to log-log plots for defect equilibria in the solid state and ionic equilibria in solution is presented. The method is based on the strictly monotone character of the functional dependence of an externally controlled thermodynamic variable (e.g. the oxygen partial pressure P(O2) for the defect equilibria in a simple oxide, or a total concentration for the ionic equilibria in solution) on a chemically relevant compositional variable (such as the electron concentration n for defect equilibria, or [H3O+] or a free ligand concentration for solution equilibria). This functional dependency can be safely inverted. The concentration of all species and the externally controlled thermodynamic variable can be calculated as a function of the chemically relevant compositional variable. The appropriate plots are then obtained using naively a spreadsheet program. This method gives exact results in many more cases than the traditional approach.
Cationic Self-diffusion in Solid Choline Perchlorate Studied by NMR
Authors: Ishida Hiroyuki , Kato Masakazu , Ono Hiroshi , Ikeda Ryuichi 
Published: February 2015

Abstract
The 1H spin-lattice and spin-spin relaxation times, and the second moment of the 1H NMR linewidth of choline Perchlorate, [(CH3)3NCH2CH2OH]ClO4, were measured in its highest-temperature solid phase, i. e. above 275 K. X-ray powder patterns taken at ca. 380 K revealed that in this phase the crystal has a CsCl-type cubic structure (a = 6.326(4) Å and Z = 1). From 1H NMR experiments it was found that the cations in this phase undergo isotropic rotation and translational self-diffusion. From the 1H T1, measurements, the activation energies of the cationic rotation and self-diffusion were evaluated to be 21.4 ± 0.4 and 62 ± 3 kJ mol-1 , respectively.