bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Properties of a New Kind of One-Dimensional Conductors. 1. General Aspects
Authors: Hanack Michael , Seelig Friedrich Franz , Strähle Joachim 
Published: February 2015

Abstract
A model for a new kind of one-dimensional conductors is presented. The compounds consist of square-planar metal complexes MX4 which are polymerised via bridging ligands L to linear chains. The bidentate ligand L, e.g. C2
2-, leads to the formation of a linear π-system along the chain, which is essential for the conductivity. The square-planar complex can be, for example, a metal phthalocyanine. MO-calculations show that this kind of polymer gives rise to a suitable energy band structure. An advantage of the new one-dimensional conductors is their flexibility; different combinations of the square-planar ligand system, the bridging ligand, and the central metal atom can be used. First experimental studies show that the preparation of the proposed conductors is possible.
Molecular Dynamics Study of Aqueous Solutions IX. Dynamical Properties of an NH4Cl Solution
Authors: Szász Gy. I. , Riede W. O. , Heinzinger K. 
Published: February 2015

Abstract
The dynamical properties of an aqueous ammonium chloride solution have been calculated from a molecular dynamics simulation over 3.5 picoseconds at a temperature of 301 K where the basic periodic cube contained 200 water molecules, 8 ammonium ions and 8 chloride ions. The effective pair potentials are based on the ST 2 water model, a rigid tetrahedral four point charge model for NH4+, and a single point charge model for CI-. The coefficients of self-diffusion and of rotational diffusion, the spectral densities of hindered translations and of librations, the correlation times of the dipole moment vector and the vector connecting the two protons in a water molecule are reported separately for the various subsystems - NH4+ , Cl-, bulk water, hydration water of NH4
+ and CI- - and are compared with the available experimental data. Implications with respect to the structure breaking ability of the ions are discussed.
Luminescence Spectra of Trans-Bis(N-Alkyliminodiacetato)- Chromate(III) Complexes
Authors: Wernicke Rainer , Schmidtke Hans-Herbert , Hoggard Patrick E. 
Published: February 2015

Abstract
Luminescence spectra at 85 K have been recorded for a series of chromium (III) complexes with alkyliminodiacetates (RIDA) of the form K[Cr(RIDA)2], R=M(methyl), E(ethyl), n-P(n-propyl), i-P(isopropyl), n-B-(n-butyl), and t-B (t-butyl). Infrared and far infrared spectra of room temperature samples were also recorded.
All of the RIDA complexes exhibited the vibronic spectrum, with a remarkable shift of the intensity maximum away from the zero phonon line, which is characteristic of trans geometry in these complexes pointing to a 2E (tetragonal symmetry label) luminescent state. A comparison of vibronic intervals with IR data suggests several bands which may be indicative of iminodiacetate coordination.
The Role of Dislocations in the Thermal Dehydration of Lithium Formate Monohydrate
Authors: Flor Giorgio , Berbenni Yittorio , Marini Amedeo 
Published: February 2015

Abstract
The kinetics of Lithium Formate Monohydrate (LFM) dehydration (single crystal samples) has been investigated at constant temperature (317 < T < 353) under dynamic vacuum both optically and thermogravimetrically.
The process takes place with an induction period followed by a constant rate period. The first one is characterized by a surface nucleation which occurs mostly in connection with dislocations emerging on the (021), (110) and (010) faces and at the vertex-intersections of these planes; the second one corresponds to the advancement of a reaction interface (formed on the planes with l ≠ 0) along the c-axis.
This topochemical model has been interpreted on the basis of the different features of the actual dislocations and of the reticular geometry of the LFM crystal.
Investigation of T1-Relaxation for OCS Rotational Transitions by Self-and Nonpolar Foreign Gas Collision
Authors: Mäder H. 
Published: February 2015

Abstract
The pressure dependence of 1/T1 has been measured at temperatures ≅ 300 K and ≅ 200 K for the carbonyl sulfide J,|M| = (0, 0)-(1, 0), (1, 0)-(2, 0), (1, 1)-(2, 1), (2, 0)-(3, 0), (2, 1)-(3, 1) and (2, 2)-(3, 2) rotational transitions by using a π, τ, π/2 pulse sequence method. T1 relaxation has been investigated for the pure gas and mixtures with He, Ne, Ar, Kr, H2, O2, N2 and CO2. The effects of molecular motion are discussed theoretically by considering the microwave field inhomogeneity and collisions of molecules with the walls of the sample cell.
Absorption magnetoakustischer Wellen in einem Hoch-Beta-Plasma
Authors: Moser F. , Räuchle E. , Schneider E. , Schüller P. G. 
Published: February 2015

Abstract
Absorption of magnetoacoustic waves in a high beta plasma The radial propagation and absorption of magnetoacoustic waves (m = 0, kz = 0) in a radially inhomogeneous, high beta plasma column of a theta pinch is investigated both theoretically and experimentally. It is shown, that viscosity is the dominant dissipative mechanism. Power absorption up to 10 MW is obtained, which corresponds to an average heating rate of 5 eV/μsec per particle.
Solubilities of Silver and Copper in Their Molten Halide Mixtures AgClx Br1-x and CuClx Br1-x
Authors: Schuster E. , Schwind A. F. , Vötsch R. , Weil K. G. 
Published: February 2015

Abstract
Solubilities of silver and copper in their molten salt mixtures AgClxBr1-x; and CuClxBr1-x were measured as a function of T and x. From the temperature dependence of the solubilities, the enthalpies and entropies of dissolution could be obtained as a function of x. Unexpectedly these functions vary nonmonotonously with x. The enthalpies and entropies of solution were calculated from the experimental values, using literature data for the sublimation functions. They are found to be linearly correlated. The results are tentatively discussed under consideration of the covalent nature of the melt.
NMR-Untersuchungen über molekulare Bewegungsprozesse in Phenylensulfiden
Authors: Jurga J. , Eckert H. , Müller-Warmuth W. 
Published: February 2015

Abstract
Internal motion in poly (p-phenylene sulfides) and in some low-molecular phenylene sulfides has been studied using NMR relaxation and broad line techniques. The relaxation rates T1
-1 in the laboratory frame at 30 or 15 MHz, and T1e
-1 in the rotating frame at 45 kHz, and the second moments (or local fields or linewidths) have been measured over an extended range of temperatures for five different materials. For the polymers, the most important process has an activation energy of approximately 40 kJ/mole; it is ascribed to reorientational random oscillations of the phenylene groups, and it depends upon the detailed polymer structure. The origin of further processes of motion observed with activation energies of 20 and 11 kcal/mole is discussed. The rather narrow lines which occur in the NMR spectra at temperatures well above the glass transition are explained by the mobile fraction of chains of the non-crystalline regions.
Surface Tension of Water. The Fowler Model
Authors: Borštnik B. , Janežič D. , Ažman A. 
Published: February 2015

Abstract
The surface tension and surface energy of water is calculated using the Fowler approximation. The direct Monte Carlo integration and the calculation using the atom-atom pair correlation funtions are reported. The configuration interaction pair potential was used. The results show that feasible agreement with the experiment can be obtained.
Isoelectronic Changes in the Core Radius of Fe3+ and Ru3+ Like Ions
Authors: Rao C. V. R. , Sen K. D. 
Published: February 2015

Abstract
Isoelectronic changes in the core radius rm , defined as the last minimum in the total radial charge density distribution function 4 π r2 ϱ(r), have been computed for Fe 3+ and Ru 3+ like ions using Hartree-Fock-Slater wave functions. It is found that a linear relationship rm
-1 = A' Z + B' holds good within each series. An attempt is made to justify this empirical relationship.
Hydrogen Stark Broadening by Ion Impacts on Moving Emitters
Authors: Seidel Joachim 
Published: February 2015

Abstract
The “classical path theory” for the plasma broadening of hydrogen lines calls for a closer examination of the influence of radiator motion on Stark profiles. For a radiator with constant velocity Stark broadening is effected by an anisotropic plasma, and in a frame of reference moving with the emitter the line shape depends not only on the radiator speed but on the direction of emission as well. From this, a somewhat intricate correlation of Stark and Doppler broadening arises which has to be taken into account in the calculation of the full line profile. As an example, broadening by plasma ions is investigated in the impact limit where a distinct dependence of Stark broadening on the emitter velocity is found especially for very heavy, immovable ions.
Time Periodic Perturbations of Quantum Systems
Authors: Kelemen A. 
Published: February 2015

Abstract
We discuss a method of calculating the mean energy of a quantum system if the latter is subjected to time periodic perturbations. This, e.g., includes the possibility of determining shapes of spectral lines for an arbitrary distribution of nonperturbed energy levels. The method is studied on a system of order 2 whose spectral line is exactly lorentzian. We prove that the next to lowest approximation reproduces this form exactly.
Rate Coefficients and Product Ion Distributions for Reactions of CO2 · CO2
+ Ions with Neutral Molecules at 300 K
Authors: Rakshit A. B. , Warneck P. 
Published: February 2015

Abstract
Reactions of CO2 · CO2
+ ions with CO, N2O, CH4, H2O, O2, COS, C2H2, C2H4, C3H6, NH3, CH3NH2, and NO have been studied using a drift tube mass spectrometer with selected ion injection. In most cases, the major reaction channel is charge transfer. Molecular displacement (switching) occurs also in several cases. In general, the measured rate coefficients agree with those calculated from Langevin or ADO theory. Two exceptions are the reactions with methylamine and nitric oxide where the rate coefficients are smaller by two orders of magnitude.
Planar Lipid Bilayers as Light Guides
Authors: Braun H. P. , Herrmann R. , Michel-Beyerle M. E. 
Published: February 2015

Abstract
The light guide properties of planar lipid bilayers are discussed and experimentally verified. The interaction between the light and the constituents of the bilayer is substantially increased since the light path is as large as the diameter of the film, e.g. of the order of several millimeters. The influence of electric fields on the bilayer and on the bilayer-torus transition region has been investigated. Field induced generation of scattering centers is detected in solvent containing bilayers.
Design of a Chemical Pulse Reactor
Authors: Denzel B. , Seelig F. F. 
Published: February 2015

Abstract
The general reaction X + Y + M → P + M may - due to substrate inhibition at the catalytic site M - give rise to bistability phenomena in an isothermal tubular fixed bed reactor. The parametric conditions for bistability in the single pellet are studied by a numerical technique. Solution of the steady state equations for a two phase model of the tubular reactor shows that narrow zones with high conversion are possible, similar to ignition zones in nonisothermal catalytic reactors. By a cyclic operation with alternating periods of charging the catalyst phase with substrate and discharging it by chemical reaction, pulses of high product concentration can be generated at the reactor outlet. This is demonstrated by simulation of the system assuming low flow velocity as it is characteristic for reaction columns with liquid mobile phase.
A Contribution to the Investigation of T2-Relaxation with a Microwave Pulse Spectrometer
Authors: Schrepp W. , Bestmann G. , Dreizler H. 
Published: February 2015

Abstract
The T2-relaxation of the 220-211 rotational transition of ethylene oxide in different vibrational states, the 13C-isotope and the perdeuterated species has been investigated by a microwave pulse spectrometer. Qualitative arguments for an explanation of the results in terms of relaxation matrix elements are given.
Die Kinetik des Zerfalls von Ditertiärbutylperoxid bei hohen Drücken und Temperaturen / The Kinetic of the Decomposition of Di-tertiary-butyl-peroxide up to High Pressures and Temperatures
Authors: Buback M. , Lendle H. 
Published: February 2015

Abstract
The decomposition of di-tertiary-butyl-peroxide dissolved in n-heptane has been measured ir-spectroscopically up to pressures of 2300 bar at temperatures between 140 °C and 200 °C. The reaction follows a first order rate law with an activation energy Ea = 151.4 ± 1.6 kJ mol-1 and an activation volume ΔV ǂ = 10.1 ± 1.1 cm3 mol-1. The effectivity of the peroxide decomposition is discussed.
Über des magnetische Verhalten von Cs2MYbF6 (M = Na, K, Rb) und Cs2NaYbBr6 / On the Magnetic Behaviour of Cs2MYbF6 (M = Na, K, Rb) and Cs2NaYbBr6
Authors: Urland Werner 
Published: February 2015

Abstract
The magnetic behaviour of Cs2MYbF6 (M = Na, K, Rb) and Cs2NaYbBr6 has been studied in the temperature range between 3.5 and 251.3 K. The magnetic data are interpreted by means of a previously developed model in which the influence of the crystal field is theoretically described by the angular overlap model. The obtained values of the angular overlap parameter eσ(R) for the individual compounds are discussed and compared with each other. The energy values of the crystal-field levels of the 2F7/2 ground state are calculated.
Condensed Aromatics. Part V
Authors: Cyvin S. J. , Brunvoll J. , Cyvin B. N. , Mastryukov V. S. 
Published: February 2015

Abstract
The five-parameter approximation is applied to a normal coordinate analysis of the in-plane molecular vibrations of naphthacene. Vibrational frequencies and mean amplitudes of vibration are reported. The mean amplitudes of vibration for the nonbonded CC distances are studied in particular on the basis of data for benzene, naphthalene, anthracene, pyrene, coronene and naphthacene. The distance types are classified, and characteristic values for the mean amplitudes of the corresponding distances in different molecules are detected.
Equivalence to Thermodynamic Functions Induced in Nonlinear Systems by Symmetries of Transformation Groups
Authors: Busse H. G. , Havsteen B. 
Published: February 2015

Abstract
Characteristic functions have been defined in nonlinear autonomous systems. These functions possess properties which are equivalent to those of the energy and the entropy concepts of thermodynamics. The new functions are induced in nonlinear systems by one parameter transformation groups. The mathematical treatment is based on canonical forms and their transformation.
On the Distribution of Major and Trace Elements Between Metal and Phosphide Phases of Some Iron Meteorites
Authors: Jochum K. P. , Seufert M. , Begemann F. 
Published: February 2015

Abstract
The concentrations of Fe, Ni, Co, P, Cu, Ga, Ge, Mo, Ru, Rh, Pd, W, Ir and Pt in the phosphides and the metal of the coarse octahedrites Campo del Cielo, Canyon Diablo, Cranbourne and Sardis, the coarsest octahedrite São Julião de Moreira and the hexahedrites Braunau and Lombard have been determined by spark source mass spectrometry. Striking differences are observed of the element contents between bulk meteorite and the phosphides as well as between the different phosphide modifications schreibersite and rhabdite. Extreme values are a 20 fold depletion of Ga and a 40 times higher content of Pd in the phosphides. A particularly strong correlation between the noble metal element content and size of phosphide aggregates is observed; it is shown that this correlation is not an artifact of the sample preparation but that is must be real.
Dynamic Ginzburg-Landau Theory for the Liquid-Solid Phase Transition
Authors: Hess S. 
Published: February 2015

Abstract
The anisotropy of the probability distribution function for the unit vector joining two nearest neighbour atoms is characterized by tensorial order parameters. For cubic symmetry, the most relevant tensor is of rank 4. Starting from an ansatz for the dependence of the (specific) internal energy, volume and entropy; the entropy production is calculated which is caused by a temporial change of the 4-th rank anisotropy tensor. A constitutive law which guarantees that the entropy production is positive leads to a nonlinear relaxation equation. It shows the features typical for a dynamic Ginzburg-Landau theory. The linearized version of the relaxation equation contains an effective relaxation time and a correlation length which exhibit a temperature dependence typical for a mean field theory. For a special case where the anisotropy tensor can be characterized by a scalar order parameter, the nonlinear relaxation equation is studied in some detail. Its stationary and spatially homogeneous solutions are zero and nonzero values for the order parameter depending on whether the temperature T is larger or smaller than the transition temperature. The unordered phase corresponds to a liquid state, the ordered phase to a simple or body centered cubic crystal. The phase transition is of 1st order. There exist also metastable states.
Ion-Solvent and Solvent-Solvent Interactions. X-ray Study of Aqueous Alkali Chloride Solutions
Authors: Pálinkás G. , Radnai T. , Hajdu F. 
Published: February 2015

Abstract
The first neighbour model, FNM, used frequently for the description of hydration has been modified by dropping the assumption that the structure of the "free" solvent is identical with that of the pure solvent. The modified model, FNM2, reproduces the experimental X-ray structure functions of alkali chloride solutions quite well and enables the study of perturbed solvent-solvent interactions. The refined structural parameters reasonably indicate the dependence of the hydration of the alkali cations on their radius and concentration. The hydration of Cl- has been found to be almost independent of both concentration and the type of counter cation.
The model assumes regular symmetry for the first neighbour coordination sphere, but the high rms deviations of the water-water distances within the shells of the aggregates indicate con-siderable individual asymmetries.
A further modification of the FNM will be discussed in a following paper.
129I/127I: a Puzzling Early Solar System Chronometer
Authors: Jordan J. , Kirsten T. , Richter H. 
Published: February 2015

Abstract
We report I-Xe ages and other relevant xenon data for seven ordinary chondrites from H and L-groups of petrologic types 4-6, which were selected on the basis of minimum weathering and shock effects. Nevertheless, no chronological order with respect to the I-Xe ages exists among the different petrologic types. We demonstrate, however, that the degree to which the 1-Xe record is preserved in these chondrites, but not necessarily the age, is dependent on the thermal metamorphic history. In order to explain the lack of chronological order among the chondrites, spatiotemporal variations in the condensation-accretion process or inhomogeneities in the isotopic composition of iodine in the solar nebula is required.
NMR Investigations of 17O, 33S, 95Mo, and 97Mo in Thiomolybdates
Authors: Kroneck P. , Lutz O. , Nolle A. 
Published: February 2015

Abstract
NMR investigations of 17O, 33S, 95Mo, and 97Mo have been used to elucidate the existence and the behaviour of the oxothiomolybdate species, MoO4-nSn2-(n = 0, 1, 2, 3, 4) in aqueous solution. Very large chemical shifts and surprisingly narrow lines have been found for these nuclei in the different species.
The Change in the Prefactor Exponent with Valence for Percolation in 3 and 4 Dimensions
Authors: Duarte J. A. M. S. , Ruskin H. J. 
Published: February 2015

Abstract
The change of the prefactor exponent for restricted valence percolation in 3 and 4 dimensions is shown to occur between valences 2 and 3 as in 2 dimensions. For valence 2 the exponent is SAW-like and after the change it assumes the normal percolative value for each dimension.
Magnetische Eigenschaften der Normaltemperaturform von CsYbO2
Authors: Urland Werner 
Published: February 2015

Abstract
The magnetic behaviour of the normal-temperature form of CsYbO2 has been studied in the temperature range between 2.8 and 251.3 K. Besides at temperatures below about 12 K the magnetic data are well interpreted by means of a model in which the influence of the crystal field is theoretically described by the angular overlap model and the influence of magnetic interaction by the molecular field model. By this the transferability of the angular overlap parameters from one compound to another is tested. The energy values of the crystal-field levels of the 2F7/2 ground state are calculated.
Search for 129Xe in Mineral Grains from Allende Inclusions: An Exercise in Miniaturized Rare Gas Analysis
Authors: Reynolds J. H. , Lumpkin G. R. , Jeffery P. M. 
Published: February 2015

Abstract
A static mass spectrometer, modified by installation of a Baur-Signer (Zürich) ion source and an ion-counting system, was used to detect xenon from single mineral grains from inclusions in the C3 meteorite Allende. The grains were melted in small conical heaters wound from tungsten wire. In almost all cases excess 129Xe from 129I decay was detected, in concentrations varying from < 1000 to 600,000 atoms per microgram. Inferred iodine concentrations increased on the average from pentlandite (0.6 ppb), to hedenbergite (21 ppb), to olivine (92 ppb), to enstatite (203 ppb) to melilite (422 ppb), but vary widely from one grain to another of the same mineral, indicating that the iodine resides in some minor phase which is included “spottily” in the bulk phases over which we had good mineralogical control. About 23,000 atoms of fissiogenic 132Xe, presumably from 244Pu decay, was detected in the largest melilite sample analyzed, but we cannot determine from this study whether the 244Pu is “spotty” like 129I or is uniformly distributed in the melilite. One can foresee that if the samples could be loaded into previously outgassed heater cones, a system such as the one described in this paper would have 132Xe blanks of ~ 50,000 atoms. It is likely that in such a system the detectability for excess Xe achieved in this paper (~ 20,000 atoms) could be substantially improved. We also ran St. Severin troilite, which contains less than ~ 33 atoms of excess 129Xe per microgram, and a single chondrule from Alllegan, wich contains higher concentrations of radiogenic xenon than were previously reported by Podosek from runs on a pile-irradiated sample.
Radial Distribution of Spallogenic K, Ca, Ti, V and Mn Isotopes in Iron Meteorites
Authors: Imamura Mineo , Shima Masako , Honda Masatake 
Published: February 2015

Abstract
Cosmic-ray-produced stable nuclides of Ca (mass number: 42, 43, 44 and 46), Ti (46, 47, 49 and 50), V (50), Cr (50, 53 and 54) and the long-lived nuclides, 40K and 53Mn were determined along the radial axes of the iron meteorites Grant and Treysa. Grant was extensively examined and the results compared with rare gas data. Although Treysa does not include enough samples to allow detailed analysis, the depth profile shows typical features for a small meteorite.
The results were compared with calculated profiles of 40K, 49Ti and 53Mn using thick bombardment data. The approximate pre-atmospheric radii of Grant and Treysa were determined to be 30 cm and 14 cm, respectively. The effect of space erosion was also estimated by comparing the data of 49Ti and radioactive 53Mn in Grant and Treysa with the calculated patterns. It is suggested that space erosion of both meteorites is small (≲ 0 . 8 Å /y ) during the cosmic-ray exposure of several hundred million years.