bluuebunny/crossref_metadata_2025 huggingface dataset:
Notizen: Bestimmung des Helixdrehsinnes cholesterischer Phasen mit der Grandjean-Cano-Methode / Determination of the Helical Sense of Cholesteric Liquid Crystals Using the Grandjean-Cano Method
Authors: Heppke G. , Oestreicher F.
Published: February 2015

A simple way of determining the helix screw sense of a cholesteric phase using the Grandjean-Cano method is described. The helix pitch as well as its sense is investigated for ten cholesteric phases, induced by mesogenic chiral com­pounds in the nematic isomere mixture of 4-methoxy-4′-n-butylazoxybenzene (Nematic Phase 4, Merck). For the chiral compounds with nematic-like molecular structure it is found that the screw sense alternates with the number of bonds between the chiral centre and the ring system.
Quadrupole Hyperfine Structure and Splitting of Δ-Levels in the Microwave Spectra of KOH,RbOH and CsOH in the 100 GHz Region
Authors: Kuijpers P. , Törring T. , Dymanus A.
Published: February 2015

Hyperfine structure of rotational transitions of KOH, RbOH and CsOH in various υ2-and l-states has been carefully measured in the 100 GHz range. From the observed splittings and broadenings information about quadrupole coupling constant (eqQ) of the K nucleus in KOH and about the spacing (EΔ - EΣ) between Σ and Δ levels in the vibrational spectrum of KOH, RbOH and CsOH has been derived. The measured value of the eqQ of KOH is close to that of KF. The separation between Σ and Δ levels is found to be rather similar for the group of the alkali hydroxides in­ creasing gradually when progressing from LiOH to CsOH.
"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

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

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

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

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

The Fermi resonance doublets of 12C16O18O and 12C16O17O were identified as weak Q-branches in the Raman spectrum of natural CO2.
Ion Energy Distribution at the Wall of a Non-Thermal Plasma
Authors: Lergon H. G. , Müller K. G.
Published: February 2015

A combined mass spectrometer - probe diagnostic is applied to investigate the energy distribution of positive ions at the wall of a positive column in Argon. With a small wall probe, perforated for ion extraction, the probe characteristic, the A+-current versus probe potential, and the A+-current versus retarding potential are measured. Electron temperature from the probe characteristic and ion temperature from the last two characteristics agree within the experimental error. The Böhm criterion can be modified by T+ = Te at the wall. With a small wall probe the sheath only partly can be reduced; for positive probe potentials a potential wall in front of the probe is built up, which acts as an energy analyzer. Ion-neutral and ion-ion collisions cannot account for the Maxwellian distribution of the ions found experimentally
The Rotational Spectrum of Monothioformic Acid IV. cis- and trans-H13C(:O)SH and HC(:18O)SH
Authors: Hocking William H. , Winnewisser Gisbert
Published: February 2015

The microwave and millimeter wave spectra of two isotopically substituted species of monothioformic acid, H13COSH and HC18OSH. have been investigated. Over 60 rotational transitions in the ground vibrational state have been assigned and measured for both the eis and trans thiol rotamers. HC(:O)SH. of each isotopic species. Rotational constants and quartic centrifugal distortion comstants of H13COSH and HC18OSH have been determined from the observed spectra. These data have been combined with previously published results on HCOSH, DCOSH. HCOSD and HCO34SH to obtain complete substitutions structures for the planar eis and trans rotamers of HC(:O)SH. All of the in-plane bond angles as well as the SH distance are significantly different for the two rotamers. For the eis rotamer the HSC and HCS angles increase by more than 2°, the OCS angle decreases by more than 3°, and the SH bond shortens compared to the trans rotamer geometry. The eis structure is: r(C-H) = 1.104 ± 0.003 Å, r(C = O) 1.203 ± 0.003 Å. r(C-S) = 1.771 ± 0.003 Å, r(S-H) = 1.335 ± 0.002 Å, ∢(OCS) = 122.5° ± 0.3°, ∢(HSC) = 94.9° ± 0.2° and ∢(HCS) = 114.4° ± 0.2°; whereas the trans structure is: r(C-S) = 1.104 ± 0.003 Å. r(C = O) = 1.205 ± 0.003 Å, r(C-S) = 1.768 ± 0.003 Å, r(S-H) = 1.354 ± 0.002 Å. ∢(OCS) = 125.9° ± 0.3°, (HSC) = 92.5° ± 0.2° and ∢(HCS) = 111.0° ± 0.2°
Sternheimer Antishielding of the Fluorine Ion in Octahedral (MeF6)4-Complexes of Transition Metals from Perturbed Angular-Correlation Measurements
Authors: Bernhardt C. , Richter F. W. , Babel D.
Published: February 2015

Sternheimer antishielding factors of fluorine in octahedral transition metal complexes have been determined from nuclear quadrupole coupling data derived from differential perturbed angularcorrelation measurements taking into account ionic and covalent contributions to the electric field gradient at the fluorine nucleus. It has been found that the antishielding effect increases with increasing d-occupation in the metal ion, but is different for perovskite and rutile complexes and cannot be described by a scalar factor for the F--ions in rutile fluorides, where the fluor position is of less than axial symmetry
On the Relation between Hartree-Fock- and Maximum Overlap Molecular Orbitals
Authors: Janoschek R.
Published: February 2015

It is pointed out that at the level of a minimum basis set ab initio HF-SCF-MO results and those from the maximum overlap method coincide. Calculated dipole moments for a variety of large molecules of the steroid type are presented
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

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

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

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

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

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

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

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

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

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

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.
Zur indirekten Bestimmung der Fundamentalkonstanten
Authors: Zygan H.
Published: February 2015

In determining the fundamental constants by indirect measurements one should not assume that a possible inaccuracy of the involved theories -in whatever respect this could occur -must inevitably result in at least one evident discrepancy between theory and experiment of the same order of magnitude.
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

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

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

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

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

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

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

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

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.
Phänomenologische Betrachtungen zum Strahlungsgesetz / A Phenomenological Extension of the Radiation Law
Authors: Hartmann Hermann
Published: February 2015

The phenomenological inclusion of an elementary length leads to a generalized radion law, which includes Plancks and Eulers laws as limiting cases.
Electrical Conductivity of High Pressure Ionized Argon
Authors: Goldbach C. , Nollez G. , Popović S. , Popović M.
Published: February 2015

In order to investigate some properties of a medium with a low number of particles in a Debye sphere, the electrical conductivity of high-pressure ionized Argon has been measured. A special emphasis is laid on the so-called "non-ideality" effects in the collective behaviour of charged particles. A kind of threshold for these effects is observed at nD ≦ 4. The observed asymptotic behaviour of the screening parameter indicates that heavy charged particles have the same influence on the screening mechanism as electrons. The experimental values of the electrical conductivity are in excellent agreement with similar recent measurements.
The Rotational Zeeman Effect of Formylchloride
Authors: Dössel K.-F. , Wiese J. , Sutter D. H.
Published: February 2015

The rotational Zeeman effect of several low J transitions of Formylchloride was investigated at fields close to 25 kGauss. The results are compared to those for Formylfluoride. The larger values for the paramagnetic susceptibilities are indicative for low lying excited electronic states which together with the comparatively large molecular electric quadrupole moments may be the reason for the low stability of the molecule.
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.
Strahlungslose Energieübertragung von angeregten N-Heteroareniumkationen zu Rhodamin B. / Non-Radiative Energy Transfer from Excited N-Heteroarenium Cations to Rhodamin B.
Authors: Bendig J. , Kreysig D.
Published: February 2015

The systems acridizinium- and N-methylacridinium ion, respectively, as energy donors and rhodamin B (tetrafluoroborate) as energy acceptor show in solutions of low viscosity (solvent : methanol) energy transfer by resonance, in which a multi-step mechanism is participating. The experimental results of the detected singlet-singlet transfer are in good agreement with the predictable values of Förster's theory, if the spectroscopic parameters of the donor and the acceptor are corrected by assumption of their dependence upon concentration.
A Test of the Linear Response Theory for Irreversible Processes
Authors: Seeberg
Published: February 2015

The temporal development of macroobservables is described within a correlation-functionformalism. The results are exact for a certain class of initial ensembles. The same problem is discussed with the help of the linear-response-formalism. The results agree under certain conditions which should be fulfilled for macroobservables.
Redeposition of Sputtered Material in a Glow-Discharge Lamp Measured by Means of an Ion Microprobe Mass Analyser
Authors: Ferreira N. P. , Büger P. A.
Published: February 2015

The redeposition of sputtered material on the target in a Grimm-type glow-discharge lamp was studied by means of an ion microprobe mass analyser (IMMA) using 16O2+ ions as bombarding species. The target was an aluminium disc with a cylindrical copper insertion, one mm in diameter. The lamp was operated at currents of 50 mA and 100 mA and a voltage of 1200 V. It is estimated that 17% of the copper atoms sputtered are redeposited and may be resputtered.
Effects of Surfactants and Electrolytes on the Nucleation of Bubbles in Gas-Supersaturated Solutions
Authors: Hemmingsen Edvard A.
Published: February 2015

Various solutions of surfactants and electrolytes were equilibrated with argon at gas pressures up to 202 atm and then decompressed to atmospheric pressure while observed visually or cinemicrographically for occurrence of bubbles. In water, the threshold gas supersaturations for spontaneous nucleation of bubbles at the glass-water interface and in the bulk liquid were 135 atm and 155 atm, respectively. Among the surfactants, only those of molecular weight less than about 330 daltons significantly decreased the cavitation thresholds; those of higher weights had no effect. The electrolytes either had small to moderate or no effect on the threshold, although the dissolved gas concentrations resulting from the solubility changes were greatly decreased. The data indicate that changes in the structure of the solvent water may affect the nucleation process.
Enthalpien von Kupfer- und Silberchalkogeniden / Enthalpies of Copper and Silver Chalcogenides
Authors: Blachnik Roger , Gunia Paul-G.
Published: February 2015

The enthalpy contents of Cu2Se, Cu2Te, Ag2Se and Ag2Te at temperatures between 350 K to 50 K above the melting points were measured in an isoperibolic drop-calorimeter. Thermodynamic data of the compounds were derived from these measurements. An analysis of the data leads to the conclusion that a high degree of order is retained in the melts of these compounds, and that the bond character of these melts is partially ionic. An unusual decrease of Cp with increasing temperature immidiately after the transition temperatures could be confirmed.
ESR of Cr3+ in Aluminium Chloride Hexahydrate
Authors: Jain V. K. , Venkateswarlu Putcha
Published: February 2015

The angular dependence of the ESR spectrum of Cr3+ ions in AlCl3 · 6H2O has been studied. In addition to the allowed fine structure lines some weak low field lines, identified as fine forbidden transitions, have been observed.
Do Free Carriers Influence Polariton Scattering Intensities in GaAs?
Authors: Claus R.
Published: February 2015

An influence of free carriers in GaAs on polariton scattering intensities is shown to take place due to two mechanismus: a) The altered LO-phonon frequency changes the electrooptic coefficient and b) the macroscopic electric field becomes changed. Both quantities influence the scattering intensities.
On the Thermal Behaviour of Some Alkali Branched Alkanoates. Note I
Authors: Ferloni P. , Sanesi M. , Tonelli P. L. , Franzosini P.
Published: February 2015

Lithium, sodium and potassium isobutyrates, isovalerates and isocaproates were submitted to a differential scanning calorimetric investigation in the temperature range between 320 K and the isotropic melt region. The collected phase transition temperatures and heat effects are compared to those of the corresponding linear isomers. In particular the occurrence of mesomorphic liquids and the width of their existence fields is discussed.
Elektronenkorrelationseffekte in der Elektronendichteverteilung von Stickstoff und Acetylen / Effects of Electron Correlation in the Electron Density Distribution of Nitrogen and Acetylene
Authors: Hase Hans-Lothar , Schulte Karl-Wilhelm , Schweig Armin
Published: February 2015

It is shown by AHF-CI calculations that the changes in the electron distribution in bonding and lone pair regions of nitrogen and acetylene due to electron correlation can be neglected when calculating electron difference densities of these molecules. The changes brought about by electron correlation are such that the electron density in interatomic regions is reduced and in atomic (core) regions increased. These results might meet general interest in the area of electron difference density determinations.
Coherent Oscillations in Biological Systems I
Authors: Kaiser Fr.
Published: February 2015

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

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

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

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.
Continued Fraction Expansions in Scattering Theory and Statistical Non-Equilibrium Mechanics
Authors: Hänggi P. , Rösel F. , Trautmann D.
Published: February 2015

We consider several main aspects of the practical application of continued fraction expansions in scattering problems and in the field of equilibrium and non-equilibrium statistical mechanics. We present some recursive algorithms needed for an efficient evaluation of continued fraction coefficients. The method is then applied to the summation of badly converging series which occur in scattering theory and to the asymptotic solution of the Schrödinger equation. In addition, the use of the method for the calculation of response functions, correlations and their derivatives in systems whose time-dependence is described by a master equation is discussed. Finally, the construction of error bounds is investigated.
Photoelectron (HeI) Spectra of Aromatic Thiocarbonyls and Corresponding S-Oxides
Authors: Bernardi Fernando , Colonna Francesco Paolo , Distefano Giuseppe , Maccagnani Gaetano , Spunta Giuseppe
Published: February 2015

The low ionization energy regions of the photoelectron (He I) spectra of several p-p′-substituted thiobenzophenones (X-C6H4)2CS and of the corresponding S-oxides (sulphines) (XC6H4)2CSO (where X = H , OCH3, CH3, I, Br, Cl and NO2) have been assigned on the basis of perturbational molecular orbital theory arguments coupled with CNDO/2 computations and substituent effects.

For the thioketones, the ordering of the outermost MO's results to be n(S), π7, π6, π5/π4, π3, n(S) being the HOMO; while for the sulphines the two outermost MO’s have π character and correspond to π7 and π6 in the thioketones.

In the light of the above results the different behaviour toward oxidation of these two classes of compounds can be rationalized.
Surface Analysis of InSb by X-Ray Photoelectron Spectroscopy (XPS)
Authors: Copperthwaite R. G. , Kunze O. A. , Lloyd J. , Neely J. A. , Tuma W.
Published: February 2015

Surface compositions of single-crystal specimens of InSb have been investigated by XPS. A correlation between the degree of surface oxidation and the type of chemical etchant used has been found. This interpretation is based on chemical-shift data and argon-ion bombardment experiments, together with XPS results obtained on polycrystalline indium and antimony
Riemannian Curvature and the Petrov Classification
Authors: Hall G. S.
Published: February 2015

A connection is shown between the Riemannian Curvatures of the wave surfaces of a null vector I at a point p in space-time and the Petrov type of the space-time at p. Some other results on Riemannian Curvature are discussed
A Method for the Study of Correlated Events in Time-of-Flight Mass-Spectrometry and its Application to Fission-Fragment Induced Desorption
Authors: Fürstenau Norbert
Published: February 2015

For experiments on fission-fragment induced desorption the detection of significant correlations between desorbed ions has been reported [1]. In this paper the method for the detection and quantitative description of these correlations will be described. The statistics of the desorption-process leads to equations for mass-line intensities of ion spectra. Using a time-to-amplitude-converter for flight-time measurements these intensities depend on interdependences of different ions desorbed by the same fission-fragment. The equations allow the computation of correlationcoefficients whose interdependence with desorption probabilities of the respective ions can be shown in Venn-diagrams. Results are given and an interpretation is suggested for fission-fragment desorbed thiamine molecular and fragment ions
The Electric Conductivity of the Molten Systems BiBr3-HgBr2 and BiBr3-CdBr2
Authors: Mentus Slavko V. , Šušić Milenko V.
Published: February 2015

The electric conductivity of the molten binary mixtures BiBr3-HgBr2 and BiBr3-CdBr2 was measured for different molar compositions of the mixtures over the temperature ranges 500-770 K and 720-870 K , respectively. The curves o f the specific conductivity as a function of composition show in the BiBr3-HgBr2 system negative and positive deviations from additivity in the HgBr2- rich and BiBr3- rich composition regions, respectively. In the BiBr3-CdBr2 system the isotherms o f specific conductivity deviate positively from additivity over the entire composition range
Retarded Integration in Classical Electrodynamics
Authors: Sorg M.
Published: February 2015

The bound and emitted four-momentum of an accelerated point charge is calculated in a direct manner without use of Gauß' or Stokes' integral theorems. This new integration procedure accounts most naturally for the retarded character of the electromagnetic interactions and, if applied to the bound four-momentum, reveals that the asymptotic condition of uniform motion in the distant past can be weakened essentially.
Ion and Water Transport through Ion Exchange Membranes
Authors: Schröter J. , Stormberg H. P.
Published: February 2015

An ion exchange membrane system is considered in which the concentration of the membrane particles is low. With the help of a perturbation procedure the transport equations for ions and solvent, the so called generalized Nernst-Planck equations can be solved up to the first order. Prescribing concentration differences for the ions, a pressure difference and an electrical field as external conditions, the fluxes and densities of ions and solvent, and the pressure within the system are calculated.
Isotropie and Anisotropie Nuclear Magnetic Shielding of 113Cd in Cadmiumhalides, Cadmiumchalcogenides and in Cadmiumcarbonate
Authors: Nolle A.
Published: February 2015

The NMR signals of 113Cd have been observed in powder samples of the cadmium halides CdF2, CdCl2, CdBr2· 4H2O, Cdl2, of the cadmium chalcogenides CdO, CdS, CdSe, CdTe and of CdCO3 . For 113Cd in CdCl2 , CdBr2-4H2O, CdS and in CdSe anisotropics of the nuclear magnetic shielding have been detected. The shielding tensor in these powders is axially symmetric. For the other specimens no anisotropics of the magnetic shielding have been found. The principal values of the magnetic shielding tensor and the shielding constants are given in an atomic reference scale.
Die Reabsorption in Anthracenkristallen im Temperaturbereich 4 < T < 300 K
Authors: Ganz S.
Published: February 2015

Fluorescence spectra and decay curves of pure anthracene crystals in dependence of the emission wave length have been investigated using different exciting frequencies. A computer program using Monte Carlo Techniques is described which simulates absorption, emission, reflection and reabsorption of photons in a crystal. This program allows the calculation of fluorescence spectra and decay curves. By comparing the results of this program with experimental data, it is possible to correct the decay time for reabsorption and to calculate the reabsorption coefficient in dependence of temperature.
Dielectric Relaxation of Aliphatic Ethers in Dilute Solutions
Authors: Hasan A. , Klages G.
Published: February 2015

Dielectric relaxation of nine primary aliphatic ethers - seven symmetric ethers of chain length C6 to C32, one asymmetric ether and one molecule with three ether groups in the chain - has been studied by loss measurements at 11 frequencies between 0.3 and 300 GHz in dilute cyclohexane and mesitylene solutions at 20°C. The absorption curves are shown not to be symmetrical. The main region has been analysed in terms of a symmetric distribution of relaxation times; the high frequency contribution due to the far infrared absorption was always less than 20%. Symmetric ethers show an increasing mean relaxation time and broadening of its distribution with increasing chain length. The spectra of cyclohexane solutions are found to contain additional short relaxation times. Compared with a, α, ω-dichlorides the mean relaxation times of symmetric ethers generally are shorter, which suggests a high mobility around C-O bonds becoming more effective in the unsymmetric ethers and even more so in the chain molecule with two methoxy end groups.
Secondary Ion Mass Spectra of Apatites
Authors: Lodding A. , Larsson S. J. , Odelius H.
Published: February 2015

The detection sensitivities and the possibilities of quantification in the ion probe analysis of microelements in tooth and bone mineralized tissue are limited partly by selective ionization yields, partly by the complicated intrinsic mass spectra of the apatite matrix. Such intrinsic spectra have been recorded for hydroxy-, fluor- and chlorapatite. The limits of analysis have been examined for most of the elements in the periodic table. With a routine SIMS technique developed for the study of mineralized tissues, the lowest concentrations for semi-quantitative measurement have been assessed to lie below 10 wt ppm for at least 20 elements and below 100 wt ppm for another 25 to 30 trace elements in apatites.
Signal to Noise Improvement in Simple Spectroscopic Line Shape Studies
Authors: Langer H. , Versmold H.
Published: February 2015

Often in spectroscopic line shape experiments one is interested in the line width of a Gaussian or Lorentzian profile. We want to call attention to a simple numerical procedure which allows a significant signal to noise improvement in such studies.
Mikroskopisches Modell eines Ionenkristalles mit einem Brown’schen Untergitter. I. Allgemeine Theorie
Authors: Tillmanns C. H. , Merten L. , Börstel G.
Published: February 2015

The rigid ion model is extended to ionic crystals with a Brownian sublattice. This sublattice is formed by particles which have the possibility to assume at least two positions along a direction overcoming a potential barrier. Such a Debye relaxation process is connected with a spontaneous dipole moment. Taking into account this additional dipole moment in the equation of motion for ionic crystals we get the corresponding equation for ionic crystals with a Brownian sublattice.

In part II of this paper this complex system of equations, which depends on temperature, is solved for a simple model of a diatomic ionic crystal.
Calculations on the rZ-Structure of Dimethylsulfoxide
Authors: Typke V.
Published: February 2015

On the basis of three different force fields the zero point average structure of dimethylsulfoxide has been calculated. Three different types of calculation were performed. It is found that the different force fields virtually do not affect the resulting parameters while the results from different types of calculation agree within three times the standard errors. The asymmetry of the methyl groups found with the calculation scheme of the rs-structure is also present in the average structure.
Vapour Pressure of Liquid Metals and Alloys
Authors: Waseda Y . , Jacob K . T. , Tsuchiya Y . , Tamaki S.
Published: February 2015

The Gibbs-Bogoliubov formalism in conjunction with the pseudopotential theory is applied to the calculation of the vapour pressure of eight liquid metals from Groups I to IV of the periodic table and of alloys (Na-K). The calculated vapour pressure of the elements and their temperature dependencies, the partial pressures, activities and boiling points of the alloys are all found to be in reasonable agreement with measured data.