bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fourier Transform Nuclear Magnetic Resonance Studies of 67Zn
Authors: Epperlein B. W. , Krüger H. , Lutz O. , Schwenk A. 
Published: February 2015

67Zn nuclear magnetic resonance studies of various solutions of diverse zinc salts in H2O and D2O are reported. In the solutions of ZnI2, ZnBr2 and ZnCl2 a remarkable chemical shift to higher frequency is observable, whilst for Zn(ClO4)2, Zn(NO3)2 and ZnSO4 no shift is detectable. The 67Zn shifts in zinc halide solutions depend on the isotopic composition of the solvent. The substitution of hydrogen by deuterium in the solvent yields for the 67Zn line an anomalous solvent isotope effect to higher frequency. Moreover for increasing temperature a linear increase of the shift and a nonlinear decrease of the linewidth for the zinc halide solutions were observed.
The ratio of the Larmor frequencies of 67Zn and 37Cl has been measured in an aqueous zinc perchlorate solution, and a magnetic moment has been calculated for 67Zn. The shielding constant for the hydrated zinc ion has been evaluated:
σ*(hydrated 67Zn++ versus 67Zn atom) = − (6.9 ± 0.1) · 10−4.
Enrichment of Radiocarbon for Dating Samples up to 75,000 Years
Authors: Grootes P. M. , Mook W. G. , Vogel J. C. , Vries A. E. de , Haring A. , Kistemaker J. 
Published: February 2015

Abstract
The range of the radiocarbon dating method can be extended by about 20,000 years by means of thermal diffusion isotopic enrichment. A description of the Clusius-Dickel type enrichment columns and their operation is given. Prior to enrichment the carbonaceous sample material is combusted to CO2 and then reduced to CO. The enriched sample is re-oxidized to CO2 . The combustion-, reduction-and oxidation-apparatus and their operation are described.
The performance of the thermal diffusion columns has been tested and an empirical, volume independent relation between the isotope separation factors of 14C 16O and all molecules with mass 〈30〉 is given
q14 - 1 = (1.13 ± 0.05) (q30 - 1) + (0.035 ± 0.005) (q30 - 1)2 .
The influence of contaminations on the reability of 14C dates obtained with this method is discussed. Laboratory contaminations can be kept below the detection limit as is shown by the preparation of two anthracite samples. Still there may be some influence on dates obtained for very old samples. As far as laboratory contaminations are concerned, dates up to 75,000 years can be obtained.
EPR of Fe3+ in Low Quartz Isomorphs A(III)B(V)O4
Authors: Krauß Ulrich , Lehmann Gerhard 
Published: February 2015

Abstract
Electron spin resonance spectra of Fe3+ in hydrothermally grown single crystals of AlPO4 , GaPO4, AlASO4 and GaAsO4 were measured at X-band and analyzed using a Spin-Hamiltonian for rhombic symmetry. The zero field splitting was found to be between about one and two times the microwave frequency, increasing regularly from AlPO4 to GaAsO4. This increase is largely due to an increase in the axial parameter D whereas the second order rhombic parameter E is practically constant. The fourth order parameter a increases exponentially with the lattice parameter ratio c0/a0 . The variation of D indicates a site distortion for GaPO4 about twice as large as in AlPO4 . For the arsenates, influences of increased covalency are apparent in addition to site distortions of comparable size. Halfwidths in the range of 18 Gauss for the phosphates and 38 Gauss for the arsenates indicate hyperfine interactions with 31P and 75As, and estimates of 0.5 and 1% spin density resp. at these nuclei are obtained, again showing increased covalency for the arsenate compounds.
A Method for Measuring Interdiffusion Coefficients in Liquids by Wave-front-shearing Interferometry
Authors: Gustafsson Silas E. , Karawacki Ernest , Okada Isao 
Published: February 2015

Abstract
A new method for measuring interdiffusion coefficients in transparent liquids is presented. By using a diffusion vessel made of fused quartz with optically flat surfaces perpendicular to the optic axis it is possible to follow the complete concentration distribution with a wave-front-shearing interferometer during the diffusion process.
Hydrogen Isotope Fractionation between HCl2
- Ion and HCl
Authors: Szydłowski J. 
Published: February 2015

Abstract
Hydrogen isotope fractionation between hydrogen dichloride ion in the condensed phase and gaseous hydrogen chloride has been studied both theoretically and experimentally. Quite good agreement between the experimental tritium fractionation factor and that theoretically calculated for two sets of vibrational data was found. Theoretical calculations of the fractionation factors of both deuterium and tritium over the large temperature range of 100-2000 K revealed some anomalies (minima and crossover points) in their temperature dependences. The relative tritium-deuterium isotope effect has also been discussed within the framework of the presently accepted statistical-thermodynamic theory in the harmonic approximation and recent works by Stern et al.
Über die Temperaturabhängigkeit der Dichte von dünnen Kupferaufdampfschichten / On the Temperature Dependence of the Density of thin Vacuum Deposited Copper Films
Authors: Wagendristel A. , Söllner E. 
Published: February 2015

Abstract
A short literature survey on the subject is given with special emphasis on discrepancies and contradictional interpretations of results. Our own experiments on thin copper films evaporated onto glass substrates at different condensation temperatures are reported. Density values were calculated from the film thickness, which was measured by Kiessig's method and from the deposited mass determined by atomic absorption spectrometry as well as gravimetric measurements. The density defect decreases with increasing film thickness, as already established, and also with temperature.
From these results together with those obtained from films which were deposited during a rapid temperature rise from the low substrate temperature to room temperature we conclude that the density defect is localized at the substrate - film boundary.
Densities and Excess Volumes of Fused Halides
Authors: Brookes H. C. , Paul R. L. 
Published: February 2015

Abstract
Densities of molten AgBr-AX (A = Li, Na, K, Rb, Cs; X = Br or Cl), AgBr-AgCl, KBr-NaBr, KBr-CsBr, KCl-KBr, and KCl-CsBr mixtures have been measured at 0.5 mole fraction using the method of Archimedean displacement. The excess volumes of mixing are all positive, except for the AgBr-LiBr system. Attempts to relate the excess volumes of the binary AgBr-ABr systems to the second order conformal solution theory of Reiss, Katz, and Kleppa are unsuccessful, since V E is large even when the diameter difference parameter, δ12, is close to zero. However, the excess volumes of the reciprocal AgBr-ACl systems at 0.5 mole fraction are found, within experimental error, to have a linear dependence on δ12. The positive deviations from conformal solution theory which occur for the alkali halide mixtures have been interpreted in terms of non-Coulombic polarisation and van der Waals interactions.
Magnetowiderstand und Bandverschiebungen an halbleitenden Wismut-Antimon-Legierungen unter hohem hydrostatischem Druck / Magnetoresistance and Band Shifts in Semiconducting Bismuth-Antimony Alloys under High Hydrostatic Pressure
Authors: Schneider Detlef , Kruse Rolf , Neubauer Helmut 
Published: February 2015

Abstract
Magnetoresistance The magnetoresistance of semiconducting Bi100-xSbx single crystals (x = 5.5 and 6.3 at % Sb) at T = 297, 77 and 63 K was measured in magnetic fields up to B = 15 T. In this region, the dependence of the magnetoresistance on the magnetic field strength exhibits a negative slope, which is characteristic for semiconductor-semimetal or semiconductor-quasimetal transitions, as previously observed by other authors in Bi-Sb alloys in the liquide He-temperature range.
The influence of hydrostatic pressure (p ≦ 15 kbar) on the extrema of magnetoresistance oscillations at T = 77 and 63 K arising from the Shubnikov-de Haas effect has been examined. The results confirm the concept of approaching and mutually repelling L-point conductivity and valence bands. For the samples investigated, the energy gaps [Eg(x = 5.5) =6.94 meV and Eg(x = 6.3) = 7.64 meV] show pressure dependences of dE/dp= -1.16 · 10-6 eV/bar at 77 K and -1.39 · 10 -6 eV/bar at 63 K, respectively.
Preparation of the samples, their characterization in terms of chemical microanalysis and dislocation densities as well as the method of applying high hydrostatic pressure are described in detail.
Magnetic-field Induced Change of the Viscosity of Diamagnetic Gases with Anisotropic Magnetic Susceptibility
Authors: Hess S. 
Published: February 2015

Abstract
The influence of a high magnetic field on the viscosity of diamagnetic gases of linear, symmetric and asymmetric top molecules is studied within the frame-work of the kinetic theory based on the Waldmann-Snider equation. The quadratic Zeeman effect associated with the anisotropic magnetic susceptibility is taken into account in addition to the usual linear Zeeman splitting.
Ground State Rotational Bands in 16O, 40Ca and 208Pb?
Authors: Lezuo K. 
Published: February 2015

Abstract
It is pointed out that a considerable amount of evidence exists to support the concept of a ground state rotational band based on tetrahedral deformation for 16O, 40Ca and 208Pb. The possible meaning of this interpretation as well as other well-known alternatives are discussed.
Gamma-Ray Induced Luminescence of Silica Gel
Authors: Breitkreutz K. , Kirmaier P. , Rabe J. G. 
Published: February 2015

Abstract
Luminescence observed on adsorption of gases and vapours (RSL) on silica gel previously ex-posed to y-rays has been investigated. The dependence of RSL intensity on absorbed radiation dose and degassing temperature of the gel prior to irradiation parallels the dependence of radio-thermoluminescence (RTL) intensity: A limiting value is reached around 1 Mrad and the intensity increases steeply on raising the degassing temperature. The RSL intensity is largest on adsorption of H2 and decreases in the order H2; O2; N2O; N2; He. The stronger the RSL effect, the more is the subsequent measured RTL reduced. The RSL emission spectrum has a maximum at 450 nm and is identical with the spectrum of RTL. In some cases bands at longer wavelengths have been observed. The RSL decays with hyperbolic kinetics which may be related to the logarithmic rate of adsorption as given by the Elovich equation. The results are discussed in terms of detrapping of charges, in this case stimulated by adsorption, and the recombination of carriers leading to excitation of luminescent centers as in RTL. The emission bands at longer wavelengths are thought to involve electron transfer from interacting molecules neutralizing holes trapped in the solid.
Bestimmung kernresonanzspektroskopischer Parameter durch Lorentz-Kurven-Form-Analyse: I [C6F5Si(CH3)2]2 / Determination of NMR Parameters by Lorentzian-Line-Shape-Analysis I: [C6F5Si(CH3)2]2
Authors: Hägele Gerhard , Lueg Volker 
Published: February 2015

Abstract
The set-up of digital-out-put for HR-CW-NMR-spectrometers and computer-programs suitable for Lorentzian-line-shape-analysis is reported. The values for 5JHF AND 6JHF IN [C6F5Si(CH3)2]2 are determined.
Absolutmessung der Leistungseinkopplung in ein Deuterium-Plasma bei der unteren Hybrid-Resonanz / Absolute Measurement of Power Transfer to a Deuterium Plasma Near the Lower Hybrid Resonance
Authors: Lammers B. , Oberlack U. , Schlüter H. 
Published: February 2015

Abstract
Absolute Measurement of Power Transfer to a Deuterium Plasma Near the Lower Hybrid Resonance The power transfer to a deuterium plasma generated by a high frequency discharge near the lower hybrid resonance is investigated in the range of several hundred watts. The results are compared with linear theories. Reasonable agreement is found between measurements and the linear theory of a bounded plasma as far as the wings of the resonance are concerned. But the dominant radial modes predicted by theory are not observed. Introduction of an empirical effective collision frequency ν* = 0.2 ωpe, however, results in good agreement between measurements and theory in the domain of these radial modes.
Spektroskopische Untersuchungen des Plasmas einer Glimmentladungslampe / Spectroscopic Investigations of the Plasma of a Glow Discharge Lamp
Authors: Büger P. A. 
Published: February 2015

Abstract
The electron concentration, the excitation temperatures (from Ar-I-, Ar-II-and Cu-lines) and the rotation-and vibration temperatures (from N2-and N2
+ -bands) have been measured in a glow discharge lamp. Spectral lines of neutral molecules indicate temperatures in the range of 3000 K. Using ion lines as indicator it could be shown that Texc > Tvib > Trot (30 000; 9300; 1190 K). The former are hardly affected by discharge parameters, the latter ones are strongly affected. At the edge of the glow the temperature is distinctly lower. The electron concentration is approx. 10 14 cm-3. The results are discussed.
EPR of Radiation Damage Centers in NaNO3, Sr(NO3)2, BaS, and MgC2O4·2H2O
Authors: Köksal F. , Yüksel H. 
Published: February 2015

Abstract
NaNO3, Sr(NO3)2, BaS, and MgC2O4·2 H2O powders have been gamma-irradiated at room temperature and their electron spin resonance spectra examined for paramagnetic species. The species identified were NO3 and NO2 radicals in the nitrates, SO2
- and S in BaS, and H2C2O4
- in magnesium oxalate. Theoretical predictions agree with these assignments.
Kinetics and Mechanism of Solid State Reactions in the Agl-TlI System
Authors: Flor Giorgio , Massarotti Vincenzo , Riccardi Riccardo 
Published: February 2015

The kinetics of the solid state reactions
AgI + TiI → AgTlI2 (I)
Agl + AgTl2I3 → 2 AgTlI2 (II)
AgTlI2 + Til → AgTl2I3 (III)
are investigated with reactant pellets by the contact method.
With the aid of inert marker experiments and transport number determinations it was possible to state that the governing mechanism is the cation counter-diffusion in all cases and that the rate determining step is the diffusion of Tl+.
The experimental reaction rate constants agree reasonably with those calculated on the basis of the Wagner's thermodynamic theory.
Folgerungen aus der fundamentalen Ungleichung / Consequences of the Fundamental Inequality
Authors: Kern W. 
Published: February 2015

Abstract
Consequences of the Fundamental Inequality An important feature of the entropyfree thermodynamics of processes is the well-known fundamental inequality. In the case of simple thermodynamic materials and on certain analytical assump-tions we deduce from it the representation of the constitutive equations for processes which remain sufficiently close to an equilibrium state.
We further consider materials which are of the differential type and of complexity one. It is shown that for such materials the equilibrium entropy, which can be used as a well-defined auxiliary function during a process, can be regarded as a possible entropy in non-equilibrium. This theorem is only based on the validity of the fundamental inequality. It is therefore an improvement of the theorem of Keller and König.
Dynamic Screening Model of the Electric Microfield Distribution
Authors: Ecker Günter H. , Schumacher Alex 
Published: February 2015

Abstract
Starting from the linearized Klimontovich equations and the pair approximation we study the probability distribution of the electric microfield. We deduce the separation of the total microfield distribution into a high and a low frequency component. We further prove that each of these com-ponents can be calculated from a model of uncorrelated, dynamically screened particles. The low frequency component, which is of prominent interest for applications, is evaluated. The results show devations from all earlier theories.
Frequency Dependence of Collisional Depolarization of Resonance Radiation
Authors: Schuller Frédéric , Behmenburg Wolfgang 
Published: February 2015

Abstract
We have studied collisional depolarization of resonance radiation with special attention given to the line wings. It is shown that in the one particle quasistatic limit the fluorescence radiation is completely depolarized, independently of frequency and perturber density. By comparison with the integrated polarization degree it is concluded, that the polarization state of the radiation must exhibit a frequency dependence.
Messung von Anregungstemperaturen in einer Glimmentladungslampe / Measurement of Excitation Temperatures in a Glow Discharge Lamp
Authors: Büger P. A. , Alfy S. El 
Published: February 2015

Abstract
Measurement of Excitation Temperatures in a Glow Discharge Lamp Excitation temperatures indicated from Fe-I and Fe-II spectral lines have been measured in a glow discharge lamp using relative intensities of 49 selected spectral lines. Different excitation temperatures resulted: the temperatures were in the range of 3000 -5000 K (Fe-I lines) and 20000 K (Fe-II lines). The former are hardly, the latter ones strongly affected by discharge parameters. The results are discussed.
Oxidation von Nickelschichten untersucht mittels Elektronenbeugung / Oxydation of Thin Ni-foils Investigated by Electron Diffraction
Authors: Drautz Siegfried , Steeb Siegfried 
Published: February 2015

Abstract
Recrystallized nickel foils were treated by oxygen (2·10-4 Torr up to 10-3 Torr) at temperatures up to 550 °C within an electron diffraction set. The treatment was done isothermal and isobaric during few minutes up to several hours. The change in structure was observed. Additional reflexions occured and could be interpreted as due to double reflexion. Under the conditions mentioned above nickel changed into nickel monoxide directly, i. e. without formation of sub-oxides or other intermediate phases. This is in accordance with the fact that up to now no sub-oxides to the transition metals of group VIII a have been found.
Bestimmung elastischer Konstanten von MBBA und EBBA mit der elektrischen Leitfähigkeitsmethode / Determination of the Elastic Constants of MBBA and EBBA by Electric Conductivity Measurements
Authors: Greulich M. , Heppke G. , Schneider F. 
Published: February 2015

Abstract
Several methods of studying the elastic behaviour of nematic liquid crystals by means of measuring the electric conductivity are discussed. The temperature dependence of the ratio of the splay and bend elastic constants to the anisotropy of the magnetic susceptibility is determined for N-(p-methoxybenzylidene) -p-n-butylaniline (MBBA), N-(p-ethoxybenzylidene) -p-n-butylaniline (EBBA) and mixtures of both.
Dispersion of Localized Mode Polaritons in K3Cu(CN)4
Authors: Nitsch Wilhelm 
Published: February 2015

Abstract
The dispersion of polaritons of symmetry A1 and E is investigated in the region of four isotopic vibrations originating from C13- and N15 -atoms in their natural abundances. The measured dispersion curves are explained in terms of a theory for localized mode polaritons (LMP) developed by Ohtaka. The dispersion relation is generalized for a polyatomic crystal and applied to K3Cu(CN)4. The comparison of experimental data with calculated dispersion curves shows a quite satisfying agreement for a certain value of the coupling constant which is approximately the same for E-type and A1-type polaritons.
Microwave Spectrum and Quadrupole Coupling Constants of 2-Bromothiophene
Authors: Mjöberg P. J. , Ralowski W. M. , Ljunggren S. O. 
Published: February 2015

Abstract
The microwave spectra of the two 79Br and 81Br isotopic species of 2-bromothiophene have been measured in the region 18000-40000 MHz.
For both isotopic species, the rotational constants of the ground state and one vibrationally excited state were determined, as well as the centrifugal distortion coefficients of the ground state. The ground state rotational constants in MHz are as follows:
C4H3
32S79Br C4H3
32S81Br
A = 5403.432 ±0.111 5403.563 ±0.095,
B = 1139.0689±0.0010 1126.5173±0.0011
C = 940.5142±0.0018 931.9315±0.0009.
In order to perform a second-order perturbation treatment of the quadrupole interaction, the matrix elements of products of direction cosines in terms of the symmetric top wave functions have been derived. By the first-and second-order perturbation analysis of the hyperfine splittings of the rotational lines, the nuclear quadrupole coupling constants have been determined. The values in MHz are
Xaa = 592.7 ±1.5 493.7 ±1.5,
Xbb = -295.3 ±0.6 -245.6 ±0.7,
Xcc = -297.4 ±1.6 -248.1 ±1.6,
Xab = 80 ±9 64±8 ,
in the principal axes system of the molecule.
Notizen: The Heats of Adsorption of the Trichloroethanes on Porous Alumina
Authors: Tribbeck T. D. 
Published: February 2015

Abstract
The trichloroethanes undergo rapid dehydrochlorination in the presence of porous transitional aluminas, at temperatures as low as 80 °C. Attempts to measure their heats of adsorption on these solids above 80 °C are therefore unsuccessful. Silica gel is an inactive dehydrochlorination catalyst, and the heat of adsorption of 1,1,2-trichloroethane measured for this material is reported.
On Excess Electron Mobility in Liquid and Glassy 3-Methylpentane
Authors: Kalinowski I. , Rabe J. G. , Schmidt W. F. 
Published: February 2015

Abstract
The temperature dependence of the excess electron mobility in liquid 3-methylpentane was measured from 258 K to 371 K. The results are compared with the data obtained by Maruyama and Funabashi in the glassy state between 4.2 K and 77 K.
Krypton-85 in the Ocean
Authors: Schröder Jörg 
Published: February 2015

Abstract
A method is described to determine for the first time the 85 Kr concentration in seawater. Samples of 220 l of seawater are degassed aboard a research vessel. The krypton contained in the gas sample is isolated in the laboratory and its 8s Kr activity is measured in a gas counter. The background of the lowel-level counting-array is 0.026 cpm; surface water samples yield a netto count-rate of 0.13 cpm. The reproducibility of the method was checked by gas standards (krypton-air mixtures) and moreover by three surface water samples; both sets agree within ± 1 σ, or ± 5%. The mean value of three samples of great depths (1600, 2000, 2000 m) is 5% of the surface water concentration. This figure represents the possible contamination of the samples by atmospheric 85 Kr during the various preparation stages (blank value). Two profiles have been measured from the North Atlantic (about 40°N, 18°W, November 1972). A strong decrease of the 85 Kr concentration is found in the upper 1000 m. In a simple one-dimensional vertical diffusion-advection model the profiles can be simulated with a coefficient of apparent vertical eddy diffusion of 5 cm 2 / sec in the depth range of 300 to 1000 m (main thermocline). A possible application of oceanic 85 Kr data is the combination of depth profiles with those of other tracers, in particular 3 H. Another application of the 85 Kr method is the dating of groundwaters younger than 20 years.
Ground State Centrifugal Distortion Constants of Trans-Acrolein, CH2 = CH — CHO from the Microwave and Millimeter Wave Rotational Spectra 1,2
Authors: Winnewisser Manfred , Winnewisser Gisbert , Honda T. , Hirota E. 
Published: February 2015

Abstract
The pure rotational spectrum of trans-acrolein in the ground vibrational state has been assigned in the frequency region from 8 GHz to 180 GHz. The measured absorption lines encompass a-type transitions from the qRK, qQ1,
qQ2 branches and 6-type transitions from the rP0, rP1, rP2, rR0 brandies for values of J up to 23. The rotational constants have been refined and all quartic and sextic centrifugal distortion constants have been determined using Watson's reduced Hamiltonian. This information has been used to predict line positions of astrophysical interest to warrant the interstellar line search for trans-acrolein.
Notizen: Resonance Quenching of Anti-Stokes Luminescence from Rhodamine B in Water Solutions
Authors: Bojarski C. , Bujko A. , Dudkiewicz J. , Twardowski R. 
Published: February 2015

Abstract
It was found that when exciting the photoluminescence of water solutions of rhodamin B in the anti-Stokes region the concentrational changes of quantum yield decrease with the decreasing frequency of the exciting light.