bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical Shifts and Coupling Constants in Copper (I)-Compounds by 63Cu and 65Cu FT-NMR Studies
Authors: Lutz O. , Oehler H. , Kroneck P.
Published: February 2015

Using 63Cu and 65Cu FT NMR, chemical shifts and large indirect spin-spin-coupling constants with phosphorus were measured in dissolved copper (I) compounds. The nuclear magnetic shielding constants derived from the chemical shifts were given in the atomic reference scale. No isotope effect for spin-spin-coupling constants was found.
MINDO/3-FORCES Study of the F- + CH4 Reaction
Authors: Shanshal Muthana
Published: February 2015

Using the MINDO/3-FORCES method the energy of the reactants, reaction products and the paths of reaction were calculated for F- + CH4. The calculated values of the cartesian force constants of five assumed structures showed that only the configuration of bipyramid (distorted C3v) and the one with flourine bonded to a hydrogen atom are possible intermediates. Starting with the bipyramid the activation energy of the retention (63.6 kcal/mol) is calculated similar to the value recently reported for the same reaction of H- + CH4. We calculated also the activation energies for the inversion (56.4 kcal/mol), H2 elimination (71.8 kcal/mol) and the proton abstraction (37.6 kcal/mol) reactions.
Continuous Diffuse Electron Scattering from Polymethylene Compounds. II. Oblique Layer Crystals
Authors: Dorset Douglas L.
Published: February 2015

The positions of continuous diffuse scattering streaks in electron diffraction patterns from oblique layer crystals isostructura l to monoclinic paraffins are predicted using the kinematical difference Fourier transform (DFT) model of Amoros and Amoros. However, indications of correlated chain motions are found as was seen in a bimolecular rectangular layer structure. This correlated chain “motion” and the large temperature factors used for the DFT calculation (which are inconsistent with X-ray crystal structure results) suggest the presence of point defects in the long chains pro­posed earlier by other workers.
Einfluß der Deuterierung auf die Phasendiagramme von (NH4, Cs) CI und (NH4,Rb)Cl / Negative Isotope Effect of the Phase Transition II —III in (NH4,Cs)Cl and (NH4,Rb)Cl
Authors: Brauer Peter , Jahn Irmin R.
Published: February 2015

The influence of substitution of NH4 by ND4 on the phase diagrams of (NH4,Cs)Cl and (NH4,Rb)Cl has been studied using the optical birefringence. We found that the tempe­rature range where the phase III exists decreases strongly with increasing deuterium content.
Boundary-Value Problem for Electromagnetic Fields in Cylindrical Conductor with Circumferential Electrodes Excited by AC-Current
Authors: Wilhelm H. E. , Hong S. H. , Boonzaier D. A.
Published: February 2015

The bounardy-value problem for the electromagnetic fields E(r, t) = {Er (r, z, t),0, Ez (r, z, t)} and B(r, t) = {0, Bθ(r, z, t),0} in an electrically conducting cylinder of radius r = a and infinite length (-∞≦z≦+∞) is treated, which are excited by a periodic ac-current I(t) = I0 cosωt entering and leaving the cylinder through circumferential electrodes at r = a and z = ± c. Solutions for E(r, t ) and B(r, t) are obtained in terms of Fourier integrals which are reduced to infinite series by means of the residue theorem. Graphical presentations of the fields E(r, z, t) and B(r, z, t) versus z and r for times ωt = 0 and π/2 are given which show the relative amplitude and phase relations of the fields. An application of the results to medical physics is discussed concerning the measurement of the electrical conductivity of the tissue of limbs.
Pulse Radiolysis of Tetraphenylcyclobutane in Hexamethylphosphoric Triamide Solution
Authors: Takamuku S. , Dinh-Ngoc B. , Schnabel W.
Published: February 2015

r-1, c-2, t-3, t-4-tetraphenvlcyclobutane (TPCB) was irradiated in dilute solutions of hexamethylphosphoric triamide (HMPT) with 20 ns pulses of 16 MeV electrons. Solvated electrons (e-
solv) produced during the radiolysis of HMPT react with TPCB with k = (6 ± 1) · 109 l/mol s. Simultaneously with the decay of the optical absorption of the solvated electrons, the formation of the absorption of t-stilbene (at 300 nm) and that of stilbene radical anions (at 500 nm) was observed.

Thus, it is concluded th at TPCB is undergoing a dissociative electron attachment process e-
solv + TPCB→t-St + t-St·̄̅.

The lifetime of a possible intermediate (TPCB·̄̅) was estimated as being smaller than 10-9 s. The 100 eV yield of t-stilbene was determined as G(t-St) = 3.4.
Solubility Isotherms of Tritium in Palladium at Low Equilibrium Pressures
Authors: Schmidt S. , Sicking G.
Published: February 2015

The solubility of tritium at low pressures in bulk palladium was analysed again. The gasvolumetric method used, working with only 2 cm3 stp tritium gas, is described. The Sieverts constants obtained obey the following relationship: In Ks = - 832/T + 6.243.
Dreidimensional abbildende Elektronenmikroskope II. Theorie elektronenoptischer Systeme mit gekrümmter Achse / Three-dimensionally Imaging Electron Microscopes II. Theory of Electron-optical Systems with a Curved Axis
Authors: Plies E. , Typke D.
Published: February 2015

An imaging and aberration theory of electron- or ion-optical systems composed of arbitrary stationary electromagnetic fields without space charges and currents in the beam-occupied region is developed. It follows the theory of systems with a straight optical axis as formulated by H. Rose. The electromagnetic field is expanded into plane multipoles about the arbitrarily curved and twisted axis. In the expansion of the eikonal, all terms are given which are needed for the calculation of the image aberrations up to the third rank (rank = Seidelian order + power of disturbing potentials + power of the chromatic deviation). For the image aberrations of the second rank, an integral expression is given, from which the single aberration integrals may be derived. Systems with single-section symmetry are treated in more detail.
Composite System Approach to Thermodynamic Stability
Authors: Rieckers A.
Published: February 2015

The theory of thermodynamic stability is worked out in terms of composite systems starting from basic principles formulated partially in operational language. In this connection a macroscopic ordering concept is introduced, and entropy is characterized as numerical measure for the degree of disorder. Various aspects of thermodynamic stability are investigated in operational and analytical terms laying special emphasis on appropriate neighbourhood sets. Some implications of metastability and neutral stability for the thermodynamic system concept are pursued.
New Aspects on Melting and Annealing Behaviour of Polymers
Authors: Haase J. , Köhler S. , Hosemann R.
Published: February 2015

Poly( 1-butene) (PB) crystallizes from the melt in a metastable modification II (mod. II) which slowly transforms into the stable modification I (mod. I). X-ray wide angle (WAXS) measurements show that in mod. I the size of the microparacrystallites (mPC’s) in chain direction, D̅012, the polydispersity gD of the size distribution in this direction, the lateral size D̅110 and the paracrystalline g110-value do not change upon annealing at temperatures up to the melting point. In mod. II, however, the sizes D̅012 and D̅110 increase with rising annealing temperature Tann. At a certain Tann and beyond a sufficient annealing time tann the size D̅012 shows a logarithmic increase with tann whereas D̅110 stays constant. Measuring melting points Tm of mod. I-samples, we found a linear relationship between Tm and 1/D̅012 according to the Thomson equation resulting in a melting point for an infinite crystal of Tm
∞ (mod. I) = 139 °C and a mean surface free energy of σ̅e′̅ (mod. I) = 47 ergs/cm2. T m versus 1/D̅012 for mod. II is linear only for high D̅012-values yielding Tm∞ (mod. II) = 130 °C and σ̅e′̅ (mod. II) = 29 ergs/cm2. However, a partially molten and afterwards quenched sample of mod. I with small mPC’s shows a mod. II-peak which fits the straight line extrapolated from the large D̅012-values. The DTA curves of mod. I-samples shift to higher temperatures and narrow after annealing although the crystallite sizes and size distributions remain as well as the paracrystalline distortions the same. X-ray and DTA measurements eliminate therefore surface premelting and selective melting of thinner and more distorted lamellae in mod. I. Upon annealing this modification, σ̅e′̅ decreases from 47 ergs/cm2 to 15 ergs/cm2 and the distribution of σe′ narrows. The latter determines predominantly the shape of the DTA curve. The Thomson equation therefore, applied to different samples links only the average crystallite size and the mean surface free energy with the melting point. In mod. I partial melting occurs independent of D̅012 and starts mainly at those mPC’s which have exposed surfaces with high σe′. At the beginning only single mPC’s or single lamellae melt, but no bundles of lamellae. The logarithmic increase of D̅012 in mod. II with tann can be explained according to Hosemann’s model of “lateral melting” also by a partial melting of mPC’s with unprotected lateral surfaces and by a consecutive solid state diffusion of their chainsegments into the two mPC’s adjacent in chain direction, increasing the averaged sizes of the long period and the lamellae thickness.
Microwave Transient Phenomena of Symmetric Top Molecules. An Extended Bloch Type Description
Authors: Mäder H. , Bomsdorf H.
Published: February 2015

The Bloch equations for the macroscopic polarization components Pr and Pi and the population difference ⊿N of a two-level system are derived with inclusion of diagonal elements of the electric dipole moment operator. The influence of such elements on the solutions is discussed. The effect of Stark-switching technique on the observed transient emission signal is considered.
Dissection of 13C/12C Isotope Effects on the Cyanoacetylene Partition Function
Authors: Bopp P. , Heinzinger K. , Wolfsberg M.
Published: February 2015

13C/12C reduced isotopic partition function ratios for the three singly 13C substituted cyanoacetylenes are calculated and are used to evaluate the thermodynamic equilibrium constants among these species. A perturbation theory method is employed to dissect both the partition function ratios and also the equilibrium constants in order to gain a better understanding of isotope effects.
Some Properties of a Quartic Potential with a Finite Binding Energy
Authors: Kesarwani R. N. , Varshni Y. P.
Published: February 2015

A potential energy function is proposed which exhibits a quartic dependence on (r - re), where re is the equilibrium interparticle distance, in the neighbourhood of re, and has a finite binding energy. To study the pattern of the eigenvalues, the WKBJ method is applied to the third order, and the relevant integrals are evaluated analytically. Results are shown graphically for a few sets of parameters. The number of vibrational states that the potential can support is determined for a range of values of the parameters. Some suggestions as to the possible applications of the proposed potential are also made.
Konsequenzen einer abbildungstheoretischen Deutung von Hückel-Parametern für die Diskussion von Charge-Transfer-Effekten in Dreizentrensystemen / Interpretation of Hüchel-Parameters by Means of a Mapping Concept: Consequences in the Discussion of Charge Transfer Effects in Three Centre Systems
Authors: Brüggemann R. , Voitländer J.
Published: February 2015

The charge-transfer effects of systems of the general type A-B-B are investigated, A being the donor. The importance of a one-to-one correspondence between Hückel-parameters and parameters such as effective nuclear charges and bond distances is pointed out. By using charge-transfer effects as an example it is shown that non-uniqueness leads to difficulties in interpreting charge-transfer effects.
Die Schwingungsstruktur der Shpolskii-Spektren von Anthracen, 9-Methyl-und 9,10-Dimethylanthracen in n-Hexan bei 77 K. I. Fluoreszenz / The Vibronic Structure of Shpolskii Spectra of Anthracene, 9-Methyl- and 9,10-Dimethylanthracene in n-Hexane at 77 K I. Fluorescene
Authors: Jung Ch. , Kawski A. , Żukowska M. I.
Published: February 2015

The fluorescence spectra of anthracene, 9-methyl- and 9,10-dimethylanthracene in n-hexane at 77 K were measured. The Franck-Condon-Factors are evaluated using equilibrium geometries, vibrational frequencies and normal coordinates of the molecules in the ground and first excited singlet state which were calculated by the QCFF/PI-method. These results are then compared with experimentally determined frequencies and estimated intensities. The new vibronic lines in the fluorescence spectra of the methylated anthracenes correspond to totally symmetric vibrations, up to 1000 cm-1 originated mostly by mixing with out-of-plane vibrations of the atoms of the anthracene skeleton. Above 1000 cm-1 these vibrations which have greater projections of their normal coordinates on the internal coordinates of the methyl groups, are not visible as vibronic lines in the fluorescence spectra. The multiplet structures of the O-O-transitions are ascertained.
Theoretical Study of Linear NiCO and CuCO and its Implication to Adsorption
Authors: Itoh Hiroyuki , Kunz A. Barry
Published: February 2015

Ab initio RHF-MO calculations are made for the linear NiCO and CuCO clusters. The ground states of them involve Ni 3d94s1 and Cu 3d104s1 electron configurations, respectively. The orbital energies of the CO 1 π-like levels in both clusters are closely similar to each other. The CO 5σ-like level shifts toward the CO 17r-like level due to the bonding interaction of the 5σ with the metal 4s and 3dZ
2. The results are discussed in relation to the difference of the 3d-level positions and the similarity of 4s levels of Ni and Cu. For NiCO both the 4s and 3d orbitals contribute to the metal-CO binding while for CuCO only the 4 s orbital contributes to it. The present results are in agreement with the UPS experiments on adsorption.
Crystalline Oxide Solid Solutions in Oxygen Potential Gradients
Authors: Schmalzried H. , Laqua W. , Lin P. L.
Published: February 2015

The steady state demixing of an initially homogeneous oxide solid solution (A, B)O in an oxygen potential field is studied theoretically and experimentally.

In case that DA > DB ≫ D0, the crystal is shifted with respect to the oxide lattice system toward the higher oxygen potential and is enriched in A at the side of the higher oxygen potential, while the transport of oxygen in the crystal is negligible. A numerical solution of the transport problem is presented, and the predicted effect is verified experimentally
Evidence for Polymorphism within the So-called “Blue Phase” of Cholesteric Esters. III. The Circular Dichroism of the Blue Phase at High Pressures
Authors: Pollmann P. , Scherer G.
Published: February 2015

The pressure dependence of the circular dichroism (CD) of a blue phase could be observed for the first time. Corresponding to measurements at normal pressure two phases (BP I, BP II) can be distinguished under high pressures too. Contrary to measurements at normal pressure it was possible to observe the CD of BP II as a function of a variable of state within the very narrow region of this phase
Experimental Stark Profile Determination of Some Plasma Broadened He I-and He II-Lines
Authors: Soltwisch H. , Kusch H. J.
Published: February 2015

Line profiles of the plasma broadened lines He I: 3188, 3889, and 5016 Å and He II: 3203, 4686 Å have been determined from measurements using a wall-stabilized quasistationary pulsed discharge as a plasma source of sufficient homogeneity. The profiles were recorded applying the rapid-scan technique to enable single-shot registration of the spectral data. Electron density values were obtained from plasma-refractivity measurements at two different wavelengths using rare gas ion-lasers as background light-sources. The electron density range in this experiment was (0.7 -1.2) · 1017 cm−3. Temperature values of pure helium plasmas resulted from absolute radiation measurements (line intensities of He II 3203 Å and 4686 Å), yielding ~ 4 · 104 K. In helium-hydrogen mixtures further used for plasma generation in the lower temperature region, temperature values could be estimated from the optically thick Balmer line Hα, yielding ~ 2 · 104 K.

Experimental line shapes and half-widths are compared with the theoretical predictions of several authors and with the results of previous measurements. In case of neutral helium lines experimental and theoretical values agree within experimental accuracy (10%), whereas for the He II-lines the measured line shapes deviate considerably from the theoretical predictions.
Schwingungsberechnungen der Species Ti2Cl10
2− , Ti2Cl9
− und TiCl5
− / Molecular Vibration Analysis of Ti2Cl10
2− , Ti2Cl9
− and TiCl5
−
Authors: Demiray A. F. , Brockner W. , Cyvin B. N. , Cyvin S. J.
Published: February 2015

Normal coordinate analyses of the chlorotitanate ions Ti2Cl10
2−Ti2Cl9
− - and TiCl5
− have been carried out following Wilson's FG matrix method. The final force constants are given in terms of symmetry coordinates, which are thoroughly specified for a Ti2Cl9
− molecular model. Assignments of the vibrational frequencies of the title compounds are proposed, and the corresponding potential energy distributions are given. The final force fields were used to calculate the mean amplitudes of vibration, of which those of TiCl5
− and selected values of Ti2Cl10
2− andTi2Cl9
− are reported.
Self-Association of Cholesterol in Carbon Tetrachloride
Authors: Kunst M. , Duijn D. van , Bordewijk P.
Published: February 2015

Analysis of infrared hydroxyl multimer absorbances of dilute solutions of cholesterol in carbon tetrachloride as a function of the monomer absorbance strongly favours the interpretation of the association of this alcohol with a monomer-dimer-tetramer model up to a molar fraction of 0.012. This model also explains very well the concentration dependence of the apparent dipole moment. Equilibrium constants and dielectric parameters have been determined. Suggestions about the structure of the various associates are made.
Solid State Electrochemical Study of Phase Equilibria and Thermodynamics of the Ternary System Y-Fe-O at Elevated Temperatures
Authors: Piekarczyk W. , Weppner W. , Rabenau A.
Published: February 2015

A solid state galvanic cell technique has been employed to determine the phase diagram of the ternary system Y-Fe-O in the temperature range from 900 to 1250 °C. Only electrical quantities need to be measured and the samples do not have to be quenched. YFeO3 and Y3Fe5O12 exist over the entire temperature range, whereas the third ternary compound YFe2O4-x is only thermodynamically stable above 1010 ± 9 °C. Above 1078 ± 15 °C YFe2O4-x comes into equilibrium with Y2O3.

With the same experimental arrangement the standard Gibbs free energies of formation ⊿G f
0 of the ternary compounds YFeO3, Y3Fe5O12 and YFe2O4 have been determined to be -1366.0 + 0.2525 X T kJ/mol (1173 ≦ T [K] ≦ 1523), - 4912.2 +0.9990 X T kJ/mol (1173≦T[K] ≦ 1523) and -1615.9 + 0.3068 x T kJ/mol (1283≦T[K] ≦ 1523) as functions of the temperature, respectively
Kinetics of BaBr2 · 2 H2O Dehydration: Comparison between Isothermal and Non-isothermal Methods
Authors: Flor Giorgio , Marini Amedeo , Berbenni Vittorio
Published: February 2015

For the dehydration processes

BaBr2 • 2 H2O → BaBr2 • H2O + H2O (I)

BaBr2 • H2O → BaBr2 + H2O (II)

a comparison was made between the experimental non-isothermal ɑ vs. t curves and those calculated on the basis of a previous isothermal study.

It was observed that for low heating rates, when the "thermal lag" is negligible, the dynamic measurements are in good agreement with the isothermal ones.

Furthermore, for process (I), two mathematical methods proposed for the interpretation of the non-isothermal TG curves were applied and the kinetic parameters so obtained were discussed
Cross Sections for the Collisions of Alkaline Earth Atoms in the 3 P Excited State with Chlorine Molecule
Authors: Kowalski Andrzej
Published: February 2015

The total attenuation cross sections, σ*, were measured for collisions of an excited atomic beam of Mg, Ca or Sr with a target of Cl2 molecules. The experimental σ* values equal: 85 Å2, 100 Å2 and 180 Å2 for Mg*, Ca* and Sr*, respectively. Moreover, the reactive cross sections, σȒ were calculated, assuming the "harpoon mechanism" for the reactions in question. The obtained values are: σȒ* (Mg* + Cl2) ≦ 61 Å2, σȒ* (Ca* + Cl2) ≦ 102 Å2, σȒ* (Sr* + Cl2) ≦ 130 Å2. The good agreement between the experimental and theoretical values shows that for this type of reaction the "harpoon mechanism" takes place
Internal Cation Mobilities in the Molten Systems (Li-Rb)N0 3 and (Li-Cs)NO s
Authors: Okada Isao , Takagi Ryuzo , Kawamura Kazutaka
Published: February 2015

The relative differences in internal cation mobilities are measured for the molten systems (Li-Rb)NO3 and (Li-Cs)NO3 over a wide range of temperatures and concentrations with a countercurrent electromigration method, and the internal mobilities are calculated from these results and the available data on the electrical conductivity.

The following phenomena are observed: (a) under some conditions the electrical mobility of Li+ is lower than that of the larger cation, (b) at a given temperature the mobility of Li+ decreases with increasing molar volume of the mixture, and (c) at low temperatures the isotherms of the mobility of the large cation show a maximum at some low concentration of that ion. These phenomena are interpreted in terms of the free space and the pair potential between cation and anion
The Influence of Detergents on the Bleaching Process, Laser Properties of Rhodamine 6G and B in Aqueous Solution
Authors: Konefał Z.
Published: February 2015

The bleaching and the laser properties of Rhodamine 6G and B in aqueous detergent solutions have been studied. The rate of bleaching depends on the concentration of the detergent. The relative quantum yields of the bleaching process for these solutions have been determined. It is found that the influence of detergents on the generation efficiency depends on the type of dye employed. From the results obtained it is concluded that the detergents influence the population of the triplet state of the lasing dye.
The Vibronic and Infrared Spectra of Europium Dibenzoylmethane Chelate with Piperidine
Authors: Zachara S.
Published: February 2015

The vibronic spectra of europium dibenzoylmethane chelate with piperidine in the neighbour-hood of the 5D0 → 7F0 line at 293 K and 77 K and the infrared absorption spectra in the region of 20- 200 cm-1 at various temperatures have been studied. It is shown that all vibrational frequencies obtained from the vibronic spectrum at 77 K can be observed in the infrared spectrum at the same temperature. For the above frequencies we assign some vibrations as belonging to irreducible representations of S4 point group symmetry.
Dynamics of Energy Transfer by Singlet Excitons in Naphthalene Crystals as Studied by Time-Resolved Spectroscopy
Authors: Auweter H. , Braun A. , Mayer U. , Schmid D.
Published: February 2015

The time-resolved sensitized fluorescence of anthracene-doped naphthalene crystals following picosecond-pulse excitation was investigated experimentally as a function of dopant concentration and temperature. The influence of the excitation intensity on the decay of pure naphthalene crystals is studied and yields an almost temperature-independent annihilation constant, yss ≈ 4 x 10-11 cm3 s-1 . The analysis of the time-resolved host and guest fluorescence shows that the energy transfer rate, kHG > changes its functional form with the guest concentration. The temperature dependence of the energy transfer rate is explained tentatively in terms of phonon relaxation and phonon promotion processes.
An Electromotive-Force Study of the Activity of Aluminium in Al-Ga, Al-Ge and Al-Ga-Ge Systems
Authors: Eslami H. , Franceschi J. de , Gambino M. , Bros J. P.
Published: February 2015

The activities of aluminium in Al-Ga, Al-Ge and Al-Ga-Ge systems were measured between 933 K and 1273 K using an e.m.f. method with a molten salt electrolyte.

The results concerning Al-Ga and Al-Ge systems are in good agreement with those previously obtained.

The E(T) curves of the 36 ternary alloys studied give also some liquid-solid equilibrium tem­peratures and allow isothermal curves of the ternary liquidus surface to be drawn.
A Molecular Dynamics Study of Aqueous Solutions. VIII. Improved Simulation and Structural Properties of a NH4Cl Solution
Authors: Szász Gy. I. , Heinzinger K.
Published: February 2015

A molecular dynamics simulation of an aqueous ammonium chloride solution has been carried out at a mass density of 1.027 g/cm3, corresponding to a 2.2 m solution, and at a temperature of T = 301 K. The effective pair potentials are based on the ST2 model of water, a rigid tetra­hedral four point charge model of NH4
+ and a single point charge model of Cl-. The calculated structural properties of this solution are discussed and compared with those obtained for alkali halide solutions. The first hydration shell of the ammonium ion contains on the average eight water molecules, it has a more complex structure than the hydration shells of cations with spherical symmetry. The static orientational order of water dipole moments indicate a structure breaking ability of NH4
+.
Tokamak Fuelling with Pellets: Effect of Transport Phenomena on the Injection Requirements
Authors: Lengyel L. L.
Published: February 2015

Results of calculations on pellet-plasma interaction that take into account transport phenomena inherent in tokamak plasmas are analyzed. It is shown that the results obtained by different authors on the optimum pellet penetration depth and required pellet injection frequencies, which are partly contradictory, can be explained by means of the different transport processes taken into account or neglected in the calculations concerned.
Gas Phase Two-Photon Spectroscopy of Polyazines: Pyrazine
Authors: Knoth I. , Neusser H. J. , Schlag E. W.
Published: February 2015

The two-photon excitation spectra of gas phase pyrazine-h4 and -d 4 in the region of the S1←S0 transition are presented. The two-photon absorption which is electronically forbidden is induced by-various vibrations of ungerade parity. Because of the different selection rules for two-photon transitions hitherto unknown vibrational frequencies in the excited state 1B3u have been determined.
Alignment and Opening of Giant Lecithin Vesicles by Electric Fields
Authors: Harbich W. , Helfrich W.
Published: February 2015

AC electric fields ware applied to suspensions of giant lecithin vesicles observed under a phase contrast microscope. Elongated vesicles were found to align parallel to the field. In sufficiently strong fields the vesicles opened at both ends and became cylinders which in some cases were immutable under further increase of the field. The cylinder parameters can be used to calculate the edge energy of the cylinder wall. For the single bilayer we obtain 2-10-6 erg cm-1.
Magnetic Field Effect on the Radical Yield of Electron Transfer Reactions Between a Dye Triplet and Heavy Atom Substituted Electron Donors
Authors: Steiner Ulrich
Published: February 2015

The radical yield in the electron transfer reactions between thionine triplet and various halogenanilines, as measured by kinetic flash spectroscopy in the microsecond time region, decreases by application of magnetic fields up to 4 kGauss. The relative magnetic field effect parallels the influence of the heavy atom substituents on the intersystem crossing rate constant in the triplet exciplex supposed to be the primary product of the electron transfer reaction. The magnetic field effect is suggested to be due to differences of the g-factors in the geminate radical pair, originating by dissociation of the triplet exciplex.
Polarization Relations and Dispersion Equations for Anisotropic Moving Media
Authors: Hebenstreit Helmut , Suchy Kurt
Published: February 2015

For media anisotropic (but not bi-anisotropic) in the comoving frame polarization relations and dispersion equations are derived using bilinear forms and quadratic forms, respectively. Specializations for media electrically anisotropic but magnetically isotropic (or vice versa) are given using (left and right) eigenvectors and eigenvalues of the material tensors.
Cation Mobilities, Including Isotope Effects, for Electromigration in Molten Mixtures of Potassium and Rubidium Nitrate
Authors: Ekhed Alf , Lundén Dr. Arnold
Published: February 2015

Electromigration of cations has been studied in molten KNO3 -RbNO 3 mixtures as a function of concentration (11 -94 mole % RbNO3 , about 380 °C) and temperature (about 10 mole % RbNO3 , 378 -560 °C). The mobility of K+ is slightly larger than that of Rb+ at all concentrations, the difference being about 3% in KNO3 -rich and 2% in RbNO3 -rich mictures. Neither for potassium nor for rubidium is the isotope effected affected much by the composition of the melt, although there is a tendency that the isotope effect for rubidium is somewhat larger in mixtures than in pure salts. Both isotope effects have the same temperature dependence in the investigated mixture as in the pure salts. The isotope effects for potassium and rubidium have also been determined for ternary NaNO3 -KNO3 -RbNO3 mixtures containing about 5 mole percent of NaNO3 and of RbNO3 . For comparison, a study of the mass effect for potassium ions in NaNO3 -KNO3 is also reported.
Solid State Transitions in Alkali Alkanoates: Diffractometric and Conductometric Measurements on Rubidium and Cesium Propanoates
Authors: Spinolo G. , Cingolani A. , Sanesi M.
Published: February 2015

Conductometric measurements on solid rubidium and cesium propanoates and X-ray powder diffraction measurements on the rubidium salt have been carried out over suitable temperature ranges. The results obtained, along with the previous ones concerning the lithium, sodium and potassium salts, have been discussed in relation to possible melting mechanisms (involving various kinds of disorder, e.g., positional, orientational, conformational) active in the alkali alkanoates family.
The Perturbed Hyperfine Structure of the 3s23d 2D-and 3s2 4d 2D-States of Al I
Authors: Falkenburg B. , Zimmermann P.
Published: February 2015

The influence of interconfiguration interaction between the nd 2D-series and the 3s3p2 configuration in Al I with regard to the magnetic hyperfine structure of the 3s2 3d 2D-and 3s2 4d 2D-states is discussed.
13C-NMR chemische Verschiebung phenylsubstituierter polycyclischer Kohlenwasserstoffe / 13C-NMR Chemical Shift of Phenylsubstituted Polycyclic Hydrocarbons
Authors: Storek W. , Sauer J. , Stößer R.
Published: February 2015

13C-NMR spectra of tetracene, rubrene, 1,3,5-tri-, penta-, and hexaphenylbenzene are reported. The discussion also includes the already known 13C-NMR data for diphenyl, 9,10-diphenyl-, 9,10-dibenzyl-, and 9,10-dimethyl-anthracene [1] as well as toluene. On the basis of CNDO/2 calculations different influences (diamagnetic and paramagnetic term, anisotropic contribution, ring current effect, geometry) on the chemical shift are analyzed for diphenyl and within the row benzene through tetracene
Some Dynamical Aspects of a Test Theory of Special Relativity
Authors: Mansouri Reza
Published: February 2015

Kinematically viable space-time theories admitting a velocity-dependent dilatation factor in addition to the Lorentz transformation between the inertial systems are considered. It is shown that these theories are very unsatisfactory, in the sense of leading neither to a unique definition of time nor to a unique formulation of a dynamics. As an example, the relativistic theory of anisotropic spacetime proposed by Bogoslovsky is shown to differ discretely from the special theory of relativity. First-order rotor experiments restrict the free parameter r in this theory to values smaller than 10-10
Eine Beschreibung von Hückel-Parametern mit Hilfe von Kennzahlen / A Description of Hüchel Parameters by Use of Characterizing Indices
Authors: Voitländer J. , Brüggemann R.
Published: February 2015

In many cases simple graph theoretical eigenvalue methods suffice to explain properties of molecules. Introducing valuations or weights of graphs (e.g. Hückel-Coulomb-and Hückel-resonance integrals) one may ask how they are related to effective nuclear charges and bond distances.

We are interested in whether such relations are bijective (injective and surjective) mappings. Injectivity and/or sujectivity can be characterized by indices, for instance “solution numbers” of non linear equations.

Using as physically motivated starting points (I) a simple effective model Hamiltonian and (II) a semiempirical formula for β (resonance integral) and a general expression for α (Coulomb integral) we can show that the mappings resulting from (I) and (II) agree with respect to their indices. Therefore we conclude that omitted terms in (I) are immaterial with respect to the mapping properties.
X-ray Scattering Factors of Ions in Crystals
Authors: Schmidt P. C. , Weiss Alarich
Published: February 2015

The atomic scattering factors for X - Rays are given for the ions Li⊕, Be2⊕, B3⊕, C4⊕, N5⊕, N3⊖, O2⊖, F⊖, Na⊕, Mg2⊕, Al3⊕, S2⊖, Cl⊖, K⊕, Ca2⊕, Sc3⊕, Ti4⊕, V5⊕, Ni, Cu⊕, Zn2⊕, Ga3⊕, Se2⊖, Br⊖, Rb⊕, Sr2⊕, Y3⊕, Pd, Ag⊕, Cd2⊕, I⊖, Cs⊕, and Ba2⊕ in the crystal. The crystal potential is simulated by a hollow charged sphere (Watson sphere model). The Hartree-Fock-Roothaan-method was used for the calculation. The crystal field affects most strongly the atomic form factors of the negative ions, especially the twofold and threefold ionized negative ions, which are unstable in the gaseous phase.
Gas Phase UPS Investigation of Trans-Azobenzenes
Authors: Millefiori S. , Millefiori A. , Pignataro S. , Distefano G. , Colonna F. P.
Published: February 2015

The first two ionization energy values of p-substituted trans-azobenzenes pX-C6H4-N = N-C6H5 (X = NH2, OCH3, OH, CH3, H, Cl, COOH and NO2) are reported. These have been obtained by U.V. (HeI and HeII) photoelectron spectroscopy (UPS). The substituent effect indicates that for electron donor substituents, the highest occupied orbital is π-type. This is confirmed by semiempirical calculations. When the substituent is H or a withdrawing group, the first two bands heavily overlap, and in these cases no certain assignment was possible, in spite of the several approaches used. The UPS data are discussed along with previous polarographic and U.V. absorption measurements.
The Structure of the Nucleons
Authors: Simon G. G. , Borkowski F. , Schmitt Ch. , Walther V. H.
Published: February 2015

Electron-proton and electron-deuteron scattering experiments in a wide four momentum range provide information about the structure of the proton and the neutron. The structure is a direct consequence of the hadronic interaction of the nucleon and reveals properties of the strong interaction. Absolute differential cross sections can be expressed in terms of electromagnetic form factors which lead to an understanding of the coupling mechanism between the electromagnetic field and the strongly interacting hadron. The structure can also be discussed in terms of charge densities, but this analysis is strongly restricted by recoil effects. The charge rms radius extracted from recent measurements is higher in the case of the proton than that derived from former fits. The higher value of the charge rms radius of the proton is in excellent agreement with the latest Lamb shift measurements.
Auswertung von ionenempfindlichen Photoplatten durch ein computergesteuertes Graukeil-Densitometer / Evaluation of Ion-sensitive Photographic Plates in Using an Optical Wedge Microdensitamiter
Authors: Knab H.-J.
Published: February 2015

A procedure for the automatic evaluation of ion-sensitive photographic plates used in spark source mass spectrography is described. Using an optical wedge microdensitometer the line-transmittance profiles are measured and stored. In a second step the transmittance profiles are converted into ion-intensity profiles, according to the equation of Franzen et al. [8], and inte-grated.

The two methods, peak height and integrated intensities, are compared in terms of precison and accuracy.
Mass Spectrometrical Study of Rare Gas Compositions and Neutron Capture Effects in Yamato-74191 (L 3) Chondrite
Authors: Takaoka Nobuo , Nagao Keisuke
Published: February 2015

The unequilibrated hypersthene chondrite Yamato-74191 was studied mass spectrometrically for rare gases released at various temperatures. Cosmogenic gases dominate in He and Ne. The meteorite contains large amounts of trapped Ar, Kr and Xe, and radiogenic 40Ar and 129Xe. Cosmic-ray irradiation and K-Ar ages were determined.

In addition to spallogenic components of Kr and Xe, isotopic excesses of 80Kr, 82Kr, 128Xe and 126Xe relative to AVCC-Kr and -Xe were found. The ratio of 80Kr-excess to 82Kr-excess is 2.66 after correction for spallogenic Kr. A correlation between 128Xe/132Xe and 129Xe/132Xe was found The 129Xe/132Xe ratio for trapped Xe in Yamato-74191 was determined as 1.12 ± 0.29 with the correlation plot.

The excesses found in Yamato-74191 are best explained by epithermal neutron capture on Br and I, and by the 127I (n, 2nβ) 126 Xe reaction. Using neutron-produced 80Kr, the neutron slowing -down density was estimated to be 0.14 ± 0.03 cm-3sec-1.

A minimum mass and a preatmospheric radius was estimated to be 470 kg and 32 cm, respectively.
Mineralogical and Petrographical Study of the Zaisho Meteorite, a Pallasite from Japan
Authors: Shima Makoto , Okada A. , Yabuki H.
Published: February 2015

The Zaisho meteorite, a pallasite from Japan, is primarily composed of nickel-iron and olivine, and contains minor amounts of troilite, schreibersite, chromite and farringtonite. The olivine of this meteorite is Fa18.6 in molar composition, and exhibits non-rounded morphology. About 17% of the olivines are kinked crystals. The formational temperature was estimated to be 1220 °C from the Mg-Fe 2+ distribution coefficient in the coexisting olivine-chromite pair.
Trace Element Contents of Selected Antarctic Meteorites.I. Weathering Effects and ALH A77005, A77257, A77278 and A77299
Authors: Biswas Swarajranjan , Ngo Hung T. , Lipschutz Michael E.
Published: February 2015

We report data for volatile/mobile Ag, As. Au, Bi, Cd, Co, Cs, Cu, Ga, In, Rb, Sb, Se, Te, TI and Zn in exterior and/or interior samples of four Antarctic meteorites from the Allan Hills (ALH) : A77005 (unique achondrite) ; A77257 (ureilite) ; A77278 (L3) ; A77299 (113). Exterior samples reflect contamination and/or leaching by weathering but trace element (ppm-ppt) contents in interior samples seem reasonable for representatives of these rare meteoritic types. The A77005 achondrite seems related to shergottites; other samples extend compositional ranges previously known for their groups or types. With suitable precautions, Antarctic meteorite finds yield trace element data as reliable as those obtained from previously - known falls.
Lattice Dynamics of Molybdenum and Chromium
Authors: Singh B. P. , Pathak L. P. , Hemkar M. P.
Published: February 2015

The frequency-wave vector dispersion relations, the frequency spectrum, the Debye temperature, the temperature dependence of the Debye-Waller factor and the mean square displacements of the atoms molybdenum and chromium, the metals for which long range forces are also important, have been computed on the basis of the extended improved Fielek model for BCC transition metals. The model considers, for the first time the d shell-d shell central interactions upto next-nearest-neighbours. The calculated results show a satisfactory agreement with the available experimental data.
A Comparative Study of the Kinetics of Electrophilic Substitution in Aromatic Substrates by Iodine Monochloride and Iodine in Potassium Iodide
Authors: Rao T. S. , Jukar R. N.
Published: February 2015

Electrophilic substitution in aromatic substrates by iodine monochloride is about 105 times faster than by iodine in potassium iodide. This is due to the permanent dipole in the iodine monochloride, with iodine as the positive end, which greatly facilitates electrophilic attack.
Closed Shell Hartree Theory with Orthonormal Orbitals
Authors: Ishikawa Yasuyuki
Published: February 2015

A natural orbital multiconfigurational SCF formalism has been applied to the closed shell Hartree theory with orthonormal orbitals. A prescription is given for constructing a single, one-electron Hamiltonian with which one can determine all the occupied orbitals. The formalism is suited to the matrix formulation of the orthogonalized Hartree theory for polyatomic systems.
Optimised Cluster Theory for the Triangular Well Potential
Authors: Swamy K. N. , Wankhede P. C.
Published: February 2015

The optimised cluster theory of Andersen and Chandler has been applied to calculate the radial distribution functions of a triangular well fluid with the width a the hard sphere diameter The results agree well with Monte Carlo Calculations of Card and Walkley.
The Relative Orientation of the Total Dipole Moment in the N-cis Lone-Electron-Pair-Trans Isomer of Allylamine
Authors: Fischer Edmund , Botskor Ivan
Published: February 2015

The dipole moment of the doubly deuterated species (CH2=CH-CH2-ND2) of N-cis Lone-electron-pair isomer of allylamine has been measured. The "isotope pulling elfect" has been used to determine the relative orientation of the total dipole moment with respect to the principal axes in the normal species. The possible effects of large amplitude motions on the observed effective dipole moments are discussed.
Millimeter Wave Rotational Spectrum and Centrifugal Distortion of Thioketene, H2C==C=S
Authors: Winnewisser Manfred , Schäfer Eckhard
Published: February 2015

a-type rotational transitions of molecules in the vibrational ground state of thioketene, H2C=C=S, have been measured in the millimeter wavelength region. The measurements yielded improved rotational constants:

A = 286 655(82) MHz,

B = 5 659.47596(72) MHz,

C = 5 544.51269(72) MHz.

A detailed centrifugal distortion analysis by means of Watson's S-reduced Hamiltonian led to the determination of four quartic, two sextic and two higher order distortion constants:

DJ = 1.08569(4) kHz, HJK = 0.716(20) Hz,

DJK = 168.269(77) kHz, HKJ = -408.7(73) Hz,

D1 = -25.46(68) Hz, LKJ = 0.65(24) Hz,

d2 = - 5.21(35) Hz, SKJ = -0.0533(24) Hz.

Effective rotational and centrifugal distortion constants using planarity conditions were calculated. The electric dipole moment of thioketene was determined to be μ = 1.01(3) D.
The Conformation and Vibrational Spectra of 1-Cyano-3-Butyne
Authors: Klaeboe P. , Moneeb M. , Törneng E. , Hopf H. , Böhm I. , Cyvin B. N. , Cyvin S. J.
Published: February 2015

The infrared spectra of 1-cyano-3-butyne were recorded in the region 4000-50 cm-1 in the vapour and liquid states, as an amorphous and as two different crystalline solids at 90 K. In addition the compound was studied as a high pressure crystalline solid at ambient temperature. Raman spectra of the liquid, including polarization measurements, and of the amorphous and the two crystalline solids at 90 K, were obtained.

The spectra revealed the existence of two conformers, anti (Cs) and gauche (C1 symmetry) in the vapour, liquid and in the amorphous solid. When annealed to ca. 140 K a metastable crystal containing one conformer (probably the gauche) was formed, when annealed to ca. 190 K a stable crystal was obtained having the other conformer (probably the anti). The latter conformer was present in the high pressure crystal.

Very accurate spectral data for each conformer were collected from the two crystalline solids, making complete assignments for the anti and gauche conformers feasible. The assignments were checked by a normal coordinate analysis. A simple diagonal force field was derived in which the same force constants were employed for the anti and gauche conformers. The mean amplitudes of vibration were calculated for both conformers.
Refractive Index and Molar Refractivity of Molten AgNO3
Authors: Aronsson Robert , Karawacki Ernest
Published: February 2015

The refractive index of molten AgNO3 has been measured for four wavelengths (6832 Å, 5145 Å, 4880 Å and 4579 Å) at temperatures up to about 80° C above the melting point. It is shown that the molar refractivity (R) of molten AgNO3 calculated according to the Lorentz-Lorenz equation is temperature (t) and hence density (ϱ) dependent. The estimated dR/dt and dR/dϱ values for visible light are 1.06 · 10-9(m3/mole K) and -0.984 · 10-9(m6/kg mole), respectively.
Condensed Aromatics. Part VI Force-Field Approximation for the Out-of-Plane Molecular Vibrations
Authors: Cyvin Bjørg N. , Neerland Grethe , Brunvoll Jon , Cyvin Sven J.
Published: February 2015

The out-of-plane vibrations of aromatic molecules are studied. Theoretical considerations are based on the “classical” Whiffen force field. The new approximation contains five numerical parameters and is considerably simpler than the one of Whiffen with seven parameters and substantially more interaction terms. The five-parameter approximation is applied with success to benzene and naphthalene.
Rotational Isomerism and the Orientation of the Total Dipole Moment
Authors: Botskor Ivan
Published: February 2015

A method for determining the orientation of the total dipole moments of distinct rotamers of the same molecule is discussed. Utilizing solely the experimental dipole moments obtained with microwave spectroscopy (gas phase) and an approximate structure, the orientation of the dipole moment can often be determined without use of bond moment considerations. Experimental data from nine rotamer pairs are analyzed to illustrate the method.
Origin of Iron Meteorite Groups IAB and IIICD
Authors: Wasson John T. , Willis John , Wai Chien M. , Kracher Alfred
Published: February 2015

Several low-Ni iron meteorites previously assigned to group IAB are reclassified IIICD on the basis of lower Ge, Ga, W and Ir concentrations and higher As concentrations; the low-Ni extreme of IIICD is now 62 mg/g, that of IAB is 64 mg/g. The resulting fractionation patterns in the two groups are quite similar. It has long been established that, in contrast to the magmatic iron meteorite groups, IAB and IIICD did not form by fractional crystallization of a metallic magma. Other models have been proposed, but all have serious flaws. A new model is proposed involving the formation of each iron in small pools of impact melt on a parent body consisting of material similar to the chondritic inclusions found in some IAB and IIICD irons, but initially unequilibrated. These impact melts ranged in temperatures from ~ 1190 K to ~ 1350 K. The degree of equilibration between melt and unmelted solids ranged from minimal at the lowest temperature to moderate at the highest temperature. The lowest temperature melts were near the cotectic in the Fe-Ni-S system with Ni contents of ~ 12 atom %. Upon cooling, these precipitated metal having ~ 600 mg/g Ni by equilibrium crystallization. The Ni-rich melt resulted from the melting of Ni-rich sulfides and metal in the unequilibrated chondritic parent. Low-Ni irons formed in high temperature melts near the composition of the FeS-Fe eutectic or somewhat more metal rich. We suggest that the decreasing Ge, Ga and refractory abundances with increasing Ni concentration reflect the trapping of these elements in oxide phases in the unequilibrated chondritic material, and that very little entered the Ni-rich melt parental to the Oktibbeha County iron. The remaining elements tended to have element/Ni ratios in the melts that were more or less independent of temperature. The remarkable correlation between I-Xe age of the chondritic inclusions and Ni content of the host metal is explained by a detailed evolution of (mega)regolith in which these groups originated. The most Ni-rich melts could only be generated from an unequilibrated chondrite parent; as the continuing deposition of impact energy produced increasingly higher grades of metamorphism, the maximum Ni content of the impact melts (and their subsequently precipitated metal) gradually decreased.