bluuebunny/crossref_metadata_2025_split huggingface dataset:
"Sub-Microsecond Pulse Heating Measurements of High Temperature Electrical Resistivity of the 3d-Transition Metals Fe, Co, and Ni"
Authors: Seydel U. , Fucke W. 
Published: February 2015

Abstract
The exploding wire technique is suitable for the determination of the electrical resistivity of metals in a wide temperature range provided that the heating of the wire material in the liquid phase occurs fast enough to avoid changes in the wire geometry due to surface tension. It is also an appropriate method for measuring latent heats of fusion especially for refractory metals. The electrical resistivity ρ and the enthalpy H are derived from time-resolved measurements of cur­ rent and voltage of exploding wires, which are part of a fast RCL-discharge circuit. The time interval for heating the wire from room temperature to the normal boiling point is typically 1 μsec. Because of the short times involved interactions with the surrounding medium are negligible. The time resolution of the system is better than 8 nsec and the estimated error of measured resistivity and enthalpy above temperatures of 1000 K is less than 4%.
For Fe, Co, and Ni the ρ (H) -dependence up to the normal boiling point and the therefrom derived ρ (T) -dependence are reported and compared with steady-state experiments.
Self-Diffusion in Liquid Antimony
Authors: Lamparter Peter , Steeb Siegfried 
Published: February 2015

Abstract
The diffusion of radioactive Sb in liquid Sb has been measured in the temperature range from 672 °C to 1029 °C by use of the long-capillary method. A measuring method is described by which the sectioning of the specimens can be avoided. The self-diffusion coefficient is represented by the equation
D= (5.46 + 0.78) · 10-4 ·exp[- (4230±310)/R T]cm2 sec-1.
It is concluded that liquid Sb shows semi-metallic behaviour.
Die Rolle von Redoxmediatoren bei der Korrosion des Bleidioxids in HBF4 The Role of Redox Mediators in the Corrosion of Lead Dioxide in HBF4
Authors: Beck Fritz 
Published: February 2015

Abstract
Layers of lead dioxide, electrochemically deposited on graphite filled polypropylene, corrode rather slowly in 1 m HBF4/1 m Pb (BF4)2 under oxygen evolution with an equivalent current den­ sity of 1 - 4 μA/cm2. The rate of corrosion may be accelerated by a factor of 100 by localized cell action with graphite. In the presence of reducing agents like Fe++ or V+++, a significant acceleration occurs as well, which is limited by transport to the surface of the oxide. The oxidized component may be regenerated continously at a lead counterelectrode. However, hydroquinone is partially oxidized irreversibly beyond the quinone stage, and Tl+ is partially incorporated as Tl2O3.
Chemically prepared lead dioxide powders corrode slowly in 1 m HBF4 as well and tend to passivate. The passivation is only partially avoided by collision with a lead surface. However, rapid dissolution occurs in the presence of reducing agents like Fe++. The acceleration is shown to exceed the stoichiometric conversion of the redox mediator. Additional measurements with Pb3O4 powders have been performed. Consequences in regard to the lead tetra-fluoborate accumulator are discussed.
pH-Dependent Fluorescence Spectra of 3-Substituted Umbelliferones
Authors: Wolfbeis Otto S. 
Published: February 2015

Abstract
Fluorescence data of 3-ethoxycarbonyl-, 3-acetyl-, 3-phephyl-, 4-methyl-3-phenyl-, 3-(2-benzothiazolyl) -and 3-cyanosubstituted 7-hydroxycoumarines are reported as a function of acidity (pH 0 - 9). Unlike umbelliferone or its 4-methyl derivative they do not exhibit significant photoautomerism in acidified solutions, but with the exception of the benzothiazolyl derivative. This behaviour can be interpreted in terms of a) steric hindrance by the substituent and b) enhanced charge delocalisation in the first excited singlet state, leading to lower basicities at the ring carbonyl oxygen.
Raman-Spectroscopic Observation of the Σ-diads of 12C16O18O and 12C16O17O
Authors: Srinivasan K. , Finsterhölzl H. , Klöckner H. W. , Illig D. , Schrötter H. W. 
Published: February 2015

Abstract
The Fermi resonance doublets of 12C16O18O and 12C16O17O were identified as weak Q-branches in the Raman spectrum of natural CO2.
Nahordnung in binären Schmelzen und Mischkristallen / Short Range Order in Binary Melts and Binary Solid Solubilities
Authors: Boos Alfred , Lamparter Peter , Steeb Siegfried 
Published: February 2015

Abstract
The X-Ray or neutron-intensity scattered from binary melts can be described in a similar way as that from a binary solid solution, namely as a sum of three contributions. One of these contributions describes the short range order scattering which consists of small angle scattering for segregated melts and which leads to premaxima for melts containing compound-like agglomerates. A method is shown to reveal the short range order parameter for the so-called simple model of the melts. A second method leads to the evaluation of the concentration of the agglomerates existing in com­ pound-forming melts for the so-called refined model of the melts.
Messung der Krypton-85-und Xenon-133-Aktivität der atmosphärischen Luft / A Method for Measurement of the Krypton-85 and Xenon-133-content in the Atmosphere
Authors: Stockburger H. , Sartorius H. 
Published: February 2015

Abstract
To measure the 85Kr and 133Xe content in the atmosphere approximately 60 m3 of dried and CO2-removed air are pumped through activated carbon (pressure 300 torr, temperature 77 K) during one week. When sampling time is over, the carbon is heated to 570 K. This gives a gas sample of 41 with more than 90% of the atmospherical krypton and xenon within two hours. With a further step of enrichment, the volume of sample is reduced to 100 ml. The final separation and purification of the rare gases from O2, N2, CO and CO2 is made chromatographically. First the xenon is sepa­rated in a column filled with molecular sieve (5A) at 390 K, after that the krypton is separated in a column with activated charcoal at room temperature with methane as a "carrier gas" and is simultaneously transported to a proportional counter (230 ml). In the first half-year of 1977 the activity levels of 85Kr and 133Xe ran to 17.7 respectively 0.19 pCi/m3 air. The variations of the rare gas-activities are indeed rather high. The xenon-activities are not correlated with the krypton-activities. In a preliminary discussion we try to find reasons for these variations.
Adsorption and Epitaxy in the System Ag-Cl on Spherical Silver Crystals
Authors: Wilken R. , Menzel E. 
Published: February 2015

Abstract
Spherical silver crystals are grown in UHV by solidification of a drop of melted material and exposed to chlorine gas with doses up to 120 X 10-6 torrsec at 20 to 60 °C. In situ investigations by RHEED have shown the known structures Ag(001) c(2 x 2) and Ag(011) (2 x 1) and new ones ("statistical chains") on Ag(011), Ag(011) (4 x 1), Ag(011) (3 x 1) and Ag(0kl) (1 X 1) near to Ag(011). Higher doses of chlorine gas have been applied in an other apparatus starting from 10-5 torr; here in situ RHEED has shown the known structures, Ag(111) (4/3 X 4/3) and other ones and finally the epitaxial connections Ag-AgCl reported earlier. Adsorption nets and epitaxy have surprising correlations in the system Ag-Cl, rarely found in other systems.
Der elektrische Widerstand von Kalium/Cäsium-Legierungen / The Electrical Resistivity of Potassium/Cesium Alloys
Authors: Bauhofer Wolfgang , Simon Arndt 
Published: February 2015

Abstract
Using a contactless measuring method we have investigated the electrical resistivity in the binary system potassium/cesium as a function of temperature and composition. Below 190 K, the isotherms of the resistivity versus the concentration show minima at the composition of the compounds K2Cs and K7Cs6. The sensitivity of the experimental method is sufficient to reveal details of the phase diagram.
Normalschwingungen und Rotationsisomerie von Polysulfidionen S2-
n(n=4 - 8) / Fundamental Vibrations and Rotational Isomers of Polysulfide Anions, Sn
2- (n = 4 - 8)
Authors: Steudel Ralf , Schuster Fritz 
Published: February 2015

Abstract
Raman spectra of (NH4)2S5 and S4Cl2 (dichlorotetrasulfane) have been recorded, and force constants have been calculated for the pentasulfide ion using an extended Urey-Bradley force field with six independent force constants. K2S5 like (NH4)2S5 is shown to contain helical S5
2-(symmetry C2) but Na2S5 consists of cis-S5
2-of symmetry C5. The force constants of S4
2- and S5
2- agree well with those of S8 and have been used to calculate the fundamental vibrations of S6
2-) S7
2-, and S8
2- in different isomeric rotational conformations. The Raman spectrum of S4Cl2 is compared with the vibrations calculated for isoelectronic S6
2-.
K/Ca-Altersbestimmungen an Kalifeldspäten
Authors: Heumann Klaus G. , Schwabenbauer Werner , Stadler Irene , Kubassek Emil 
Published: February 2015

Abstract
A method for the potassium/calcium age determination of geological material is described. The calcium isotope inten­sities are measured with a mass spectrometer by the thermal ionization technique. The 42Ca/44Ca isotope ratio is used as an internal standard to correct the measured 40Ca/42Ca ratio for mass discrimination. The radiogenic 40Ca portion and the calcium content of the minerals are determined in different analytical steps. Two feldspars are dated with relative stan­dard deviations of 1.8 and 4 per cent, respectively.
Die Zeitabhängigkeit der Emissionsanisotropie, gemessen an 9-Methylanthracen in Azetylzellulosefolie / The Time Dependent Emission Anisotropy of 9-methylanthracene
Authors: Kamiński J. , Kawski A. , Schmillen A. 
Published: February 2015

Abstract
The time dependence of the emission anisotropy r(t) after linearly polarised impulse excitation gives information about the intermolecular energy transfer. According to the usual theory of the energy transfer between donors and acceptors - neglecting remigration - ln r/r0 should depend linearly on √t/τ. The measurements on 9-methylanthracene in foiles of acetylcellulose are in agreement with this prediction if one takes a second thermally conditioned depolarisation com­ ponent into consideration. From the slope of the experimental plot a critical transfer distance of 24.2 Å is obtained.
Ligand-Field Calculations on Pseudo-Tetragonal High-Spin Fe(II) Compounds
Authors: Vermaas A. , Groeneveld W. L. , Reedijk J. 
Published: February 2015

Abstract
The compounds Fe(pz)4X2 and Fe(mpz)4X2, where pz stands for pyrazole, mpz for 5-methyl-pyrazole and X means Cl, Br or I, have been investigated by magnetic susceptibility, magnetic saturation and Mössbauer spectroscopy. The experimental temperatures vary from 2K to room temperature for the magnetic susceptibility measurements and from 4K to room temperature for the Mössbauer measurements. Mössbauer spectra in an applied magnetic field are also reported. The results of both types of measurements and ligand-field spectra are interpreted using a ligand-field theory. The tetragonal ground-state splitting parameters have been determined using the ligand-field spectra. For the pyrazole compounds, the experimental data nicely agree with theoretical results. The quadrupole splitting and the magnetic properties of these com­ pounds can be completely described within the used model, assuming a tetragonal molecular point symmetry. For the 5-methylpyrazole compounds, the measurements show that the point symmetry is lower than tetragonal. The agreement between the experimental data and the theoretical results for a point group Ci is less fair, especially concerning the Vzz and η values. Besides the Vzz values of Fe(mpz)4X2 differ significantly from those of the corresponding Fe(pz)4X2 compounds.
The Hyperfine Structure in the Rotational Spectrum of CuCl
Authors: Tiemann E. , Hoeft J. 
Published: February 2015

Abstract
The hyperfine structure of the rotational transition J = 1 ← 0 of 63Cu35Cl in the ground vibrational state was observed. The analysis resulted in the following nuclear quadrupole coupling constants: 63Cu: e q0 Q= +16.08(20) MHz; 35Cl: eq0 Q = - 32.25(15) MHz. The influence of the small magnetic spin rotational coupling of both nuclei on the hyperfine spectrum is discussed.
Thermal Ion-Molecule Reactions in Oxygen-Containing Molecules. Condensation-Elimination Reactions in Dimethyl Ether-Trioxane Mixtures
Authors: Kumakura Minoru , Sugiura Toshio 
Published: February 2015

Abstract
Thermal ion-molecule reactions in dimethyl ether - trioxane mixtures have been studied with a time-of-flight mass spectrometer. The appearance potentials and ionization efficiency curves of product and major fragment ions were measured by an RPD technique. The product ions, having a linear structure such as CH3OCH3(CH2O)n
+, CH3OCH3(CH2O)nH+, CH3OCH2(CH2O)n
+, and CH3OCH2(CH2O)nH+ (n = 1 - 3), are formed by condensation-elimination reactions of CH3OCH3
+ and CH3OCH2
+ with trioxane. The formation of the product ions involves the dissociation of an intermediate-complex, which has a linear structure. It was found that homo-elimination of neutral products occurs preferentially from the trioxane molecule site in the complex. Extensive scrambling does not take place. The rate constants for the ions formed in dimethyl ether (or dimethyl-d6 ether) - trioxane mixtures are obtained, and a small isotope effect is observed. The rate constants of the condensation-elimination reactions of CH3OCH2+ with trioxane are compared with those with dimethyl ether.
Vorschlag eines Weges zur einheitlichen Beschreibung der Elementarteilchen / Recommendation of a Way to a Unified Description of Elementary Particles
Authors: Heim Burkhard 
Published: February 2015

Abstract
This paper presents a concise overview of a voluminous theoretical study whose subject is a unified description of elementary particles. First of all, the empirical basis of the theoretical deliberations is presented and the most promising logical path is explored. Proceeding from equivalence principles and the fact that a unified description of the material world must be a unified theory of elementary particles a path is sketched that leads from a classical gravitation theory and a nonhermitian quantum structure theory to a representation of unified terms in a 6-dimensional carrier space of a Hilbert space. The equivalence of mass terms and the eigenvalue spectrum is then discussed. The necessity of a polymetric structure theory is developed from the cosmogeny of a protouniverse. A further demonstration shows that the consequent realisation of such a polymetric representation allows the separation from the pseudo-continuum of the discrete point spectrum of ponderable mass terms (to be interpreted as elementary particles) of all possible energetic field masses. This provides the desired unified description of the characteristics of the elementary particles. From this description it is evident that these elementary particles appear as final units. Structural characteristics are determined by complicated time expanded inner structures that, among other things, determine radioactive decay.
This overview introduces the developmental paths as a work that evidently leads to a unified quantum field theory of matter and gravitation.
Pseudopotential Theory for Molecules
Authors: Szasz Levente 
Published: February 2015

Abstract
The new exact formulation of the pseudopotential theory developed in several previous publications is used to formulate a comprehensive pseudopotential theory of molecules. It is assumed that the pseudopotential theory can be applied to molecules in which there are n valence electrons plus cores which are the same in the molecule as in the separated atoms. Using the exact pseudopotential formulation it is shown that the molecular model Hamiltonian of the n valence electrons can be built up from the model Hamiltonians of the valence electrons of the separated atoms. The model Hamiltonian is written in terms of simple model potentials. For the determination of the model potentials simple rules are derived. It is shown that the model potentials, in which the many-valence-electron effects are fully taken into account can be determined using the Hartree-Fock data for the separated neutral atoms. It is shown that the molecular model Hamiltonian is removed from the exact one by two approximations which are shown to be accurate if the model potentials are properly chosen. The computational procedures are elucidated by discussing the examples of the molecules Cl2, Hg2 and HgH.
Selfconsistent Optimization of Molecular Geometries by Semi-empirical Force Field MethodII. Relaxational Effects Accompanying Torsion in Formamide
Authors: Nalewajski Roman F. 
Published: February 2015

Abstract
The geometry relaxation effects accompanying the internal rotation in formamide are investigated using the selfconsistent MINDO force field procedure 1. The results of test calculations of H2O2 are also briefly summarized. The relaxation appears to be necessary for the barrier to the NH2 in­ version in formamide to be obtained. The calculated fully optimized equilibrium geometries of CHONH2 and H2O2 are in good agreement with experiment. However, during the rotation geo­ metry variations appear to be quite large. Application to formamide shows that torsion and in­ version are strongly coupled. The nature of the barriers calculated is analyzed in terms of the MINDO energy partitioning. Finally, it is shown that the frozen-frame variations of the charges on atoms and dipole moment of formamide, are strongly affected by the geometry optimization during rotation.
Non Linear Dependence of the First Ionization Energy of Diphenylsulphides and Diphenylethers on σP
+ Constants
Authors: Buemi G. , Pignataro S. , Spunta G. 
Published: February 2015

Abstract
The first ionization energy of several mono and bisubstituted diphenylsulphides and diphenylethers have been measured by photoelectron spectroscopy and plotted against o substituent constants. A sinusoidal dependence has been found in all cases. Such finding has been interpreted as probably due to conformational variations of the diphenylsulphide and diphenylether systems with the substituent.
Density of States for a Three-dimensional Disordered Alloy
Authors: Pumpernik D. , Borštnik B. , Kertesz M. , Ažman A. 
Published: February 2015

Abstract
Densities of states for three-dimensional models of binary alloys are calculated with a method based on the negative eigenvalue theorem. Comparison is made with the densities of states obtained by diagonalizations of the Hamiltonian for a certain number of physically different clusters of impurities.
Photoablösung von Elektronen der Ionen B-, Ga-, In-, Tl-, Ge-, Sn- und Pb- / Photodetachment of Electrons of the Ions B-, Ga-, In-, Tl-, Ge-, Sn- and Pb-
Authors: Feldmann D. , Rackwitz R. , Heinicke E. , Kaiser H. J. 
Published: February 2015

Abstract
The photodetachment cross sections have been measured in the photon energy range between 0.5 eV and 3 eV using a crossed beam apparatus with a conventional light source.
Some Properties of the Mixing Parameter in the Analysis of Molecular Vibrations
Authors: Ananthakrishnan T. R. 
Published: February 2015

Abstract
A mathematical proof is given for the range - π/4<Φ<+π/4 of the mixing parameter Φ in the case of vibrational problems of order two. The parameters Φ and

corresponding to the cases before and after isotopic substitution of atoms in molecules are shown to be related as tan Φ = A tan tan

- B, where A and B are terms depending upon the molecular structure and vibrational frequencies.
Spin-Bahn-Kopplungseffekte in nicht-ebenen Biarylen / Spin-orbit Coupling Effects in Non-planar Biaryls
Authors: Zander M. 
Published: February 2015

Abstract
The non-planar biaryls 2,2′-dimethyl-biphenyl, 1,1′-bi-naphthyl and 9,9′-biphenanthryl have higher phosphorescence/fluorescence quantum yield ratios than biphenyl, naphthalene and phenanthrene respectively. The increase of spin-orbit coupling in 1,1′-binaphthyl in comparison to naphthalene results in an increase of the phosphorescence transition probability while the triplet formation quantum yield is not enhanced. The much weaker effect of an external heavy atom pertuber on the spin-forbidden electronic tran­ sition rate probabilities in the case of 1,1′-binaphthyl in comparison to naphthalene is explained on the basis of a weaker charge-transfer interaction between luminescer and pertuber in the case of binaphthyl.
Thermoelectric Power of the Molten Systems (Cu, Ag) X (X=Cl, Br, I)
Authors: Schiraldi Alberto , Pezzati Elisabetta 
Published: February 2015

Initial thermoelectric power determinations were carried out on the molten systems (Cu, Ag)X, (X=Cl, Br, I) at 1000 K. As for the employing of either cooper or silver electrodes thermocells, the choice was based on literature thermodynamic data.
Comparison between ideal and actual behaviour allowed to discover negative excess partial ionic entropies.
Coherent Oscillations in Biological Systems I
Authors: Kaiser Fr. 
Published: February 2015

Abstract
The concept of long range coherence in biological systems of Fröhlich and its physical basis as well as his general theoretical considerations leading to the brain wave model are reviewed. The importance of these ideas is stressed both, as a possible explanation of the increasing experimental results and as a starting point to allow a theoretical description of biological events. The brain wave model is studied in detail. All possible bifurcations and the stability of the steady states is considered. The existence, stability and direction of bifurcation of a stable limit cycle is proven. The system may exhibit different types of phase transitions when it is externally disturbed. Phase plane diagrams, arguments of catastrophe theory and approximations to the model equations give a qualitative description of the system's time behaviour. Correspondence between this limit cycle model and nerve impulse generating models is established.
The Stewart-Thompson Theory applied to the Glow Discharge
Authors: Büger P. A. , Blum F. , Schilling J. H. 
Published: February 2015

Abstract
The surface topography developed on copper-based and ferrous alloys after being sputtered in a glow discharge lamp and in an ion microprobe was studied by means of a scanning electron microscope and an ion microprobe mass analyser. The observed surface topography, though obtained under completely different conditions, was found to be similar to that predicted by the theory of Stewart and Thompson.
Geometrical Models for Liquid Metals and Alloys
Authors: Blétry J. 
Published: February 2015

Abstract
The structure of monoatomic liquids in the static approximation is described by a soft sphere model and the corresponding equation of state is derived. This geometrical model is then extended to binary liquid or amorphous substitution alloys where both components have the same size. The structure of these alloys is shown to be determined by the first neighbour order parameter which is positive, negative or zero for segregated, ordered or disordered alloys respectively. The variations of the partial structure factors with concentration are presented for these three cases. Size effects are then studied by varying the ratio of atomic diameters. Many experimental results are shown to fit this simple framework.
The Electrical Conductance of Some Alkali- and Divalent Transition Metal TCNQ Salts
Authors: Afify H. H. , Abdel-Kerim F. M. , Aly H. F. , Shabaka A. A. 
Published: February 2015

Abstract
The electrical resistivity of the tetracyanoquinodimethane salts of ten alkali and transition metal cations has been investigated at temperatures from 300 to 470 K. The measurements indicate a phase transition, the activation energy of conductance being smaller in the high temperature region. The nature of this phase transition is discussed.