bluuebunny/crossref_metadata_2025 huggingface dataset:
Some Investigations of the Chemiluminescence Spectra from the Reactions of Ca and Sr with SF6
Authors: Berneike W. , Löffler H. J. , Neuert H.
Published: February 2015

The appearance of the chemiluminescence spectra from the reactions of the alkaline earth metals M = Ca and Sr with SF6 is only understood by the participation of excited metal atoms in the reactions. This has been ascertained by measuring the dependence of the intensities of the metastable Ca-line 657.3 nm and of a representative CaF band on the SF6 gas pressure in the reaction chamber. By a detailed analysis of the well resolved A -X-and B - X-systems of both of the reactions some earlier values of Do(F-SF5) given in the literature can be excluded, while the recently found value (Kiang et al.) of 3.9 ±0.14 eV is well confirmed.
Monte Carlo Calculations on Molten T1C1, TlBr and Til
Authors: Margheritis Chiara
Published: February 2015

Molten TlCl, TlBr and TlI were computer simulated at two different temperatures using the interionic pair potentials obtained by Mayer on the corresponding solids. The calculated molar volumes in comparison with the experimental ones show that the simulated molten TlCl and TlBr are only slightly relaxed (1-2, 2-3%, respectively). On the contrary, molten TlI is strongly relaxed (23-27%) and behaves as if an important cohesive force like the homopolar one would be lacking
Nachweis der re-entrant nematischen Phase an verschiedenen homologen biaromatischen Flussigkristallen durch Untersuchung binarer Mischsysteme / Re-entrant Nematic Phase Established for Several Homologous Biaromatic Liquid Crystals by Investigation of Binary Mixed Systems
Authors: Göbl-Wunsch A. , Heppke G. , Hopf R.
Published: February 2015

Several homologous series of biaromatic liquid crystals with structure type CnH2n+1O • C6H4 • M•C6H4-CN are investigated. By studying the phase transition temperatures in binary mixed systems a "re-entrant" nematic phase N(re) is established for all compounds exhibiting smectic A phases. The virtual transition temperatures N(re) - SA are found to decrease with increasing chain length of the alkyloxy group. The influence of the middle group M on the re-entrant behaviour can be attributed mainly to its dipole moment. The temperature range of the smectic A phase decreases when the middle group dipole moment is additive to that of the nitrile group. To summarize it can be said that the "re-entrant" behaviour of biaromatic liquid crystals is found to be very similar to that of triaromatic systems reported recently
Solution to Stellarator Boundary Value Problems with Set of Simple Toroidal Harmonic Functions
Authors: Dommaschk W.
Published: February 2015

Two types of 3D boundary value problems are solved for boundary conditions on a closed toroidal surface with axial or N-fold symmetry around the Z axis of a cylindrical coordinate system R, Φ, Z. In case I a surface current distribution is computed which generates inside the torus a given magnetic vacuum field. In case II a vacuum field within the torus with finite toroidal flux and zero surface normal is calculated. The method of solution is based on the availability of some complete set of auxiliary field harmonics which are regular outside the torus in case I and regular inside the torus in case II. The applied formalism is presented together with a new complete set of special field harmonics suited for case II and especially for the analytical representation of stellarator fields. The convergence of the solution method is tested and examples relating to stellarator field configurations are shown
Individual Peeling of Multiple Singular Points
Authors: Gurel Okan
Published: February 2015

It is shown that certain systems may exhibit multiple generating singular points which individually peel to result exploded points or limit cycles
Explicit Asymptotic Magnetic Surfaces
Authors: Lortz Dietrich , Nührenberg Jürgen
Published: February 2015

Toroidal magnetic fields B = B0 + εB1 + ..., where the unperturbed field B0 has closed lines of force, are considered. Single-valued formal solutions F = F0 + εF1 + ... of the equation B · ▽F = 0 are explicitly determined
Depolarization Thermocurrents in Ice Ih at Low Temperature
Authors: Pissis P. , Boudouris G. , Garson J. C. , Lévêque J. L.
Published: February 2015

Polycrystalline ice samples frozen from highly purified water have been investigated by means of the depolarization thermo-current (DTC) technique in the temperature range 85-250 K. Three peaks have been observed at temperatures about 125, 165, and 225 K at a heating rate of 3.5 K/min. The measurements confirm most of the results reported by Johari and Jones. The characteristics of the low temperature DTC peak have been examined extensively for different samples, different heating rates and different polarization conditions. This peak has been found to be non-Debye. Its multiplicity has been studied experimentally using the possibilities offered by the DTC method. It may be better represented by a continuous ditribution of relaxation times than by a sum of discrete relaxation processes
Nonlocal Susceptibilities and Molecular Electric Quadrupole Moments of 3-Fluoropyridine and 2,6-Difluoropyridine, a Rotational Zeeman Effect Study
Authors: Hübner D. , Stolze M. , Sutter D. H.
Published: February 2015

The rotational Zeeman effect spectra of 3-Fluoropyridine and 2,6-Difluoropyridine have been measured. The molecular g-values are gaa = - 0.0917(5), gbb = - 0.0476(5), gcc = +0.0194(5) for 3-Fluoropyridine and gaa= -0.0573(6), gbb =0.0311(6), gcc =0.0102(6) for 2,6-Difluoro- pyridine. The values for the magnetic susceptibility anisotropics in units of 10-6 erg/(G2 mol) are 2Xaa+Xbb + Xcc = 53.3(8), 2Xbb-Xcc-Xaa = 60.5(7) for 3-Fluoropyridine and 2Xaa-Xbb -Xcc = 48.4(11), 2Xbb-Xcc-Xaa=51.7(11) for 2,6-Difluoropyridine. Subtraction of the local atom contributions to the magnetic susceptibilities indicates that Fluorine quenching of the nonlocal out of plane contribution depends on the position of the substituent. Further, the data suggest a linear correlation between X⟂
nonlocal and the “CNDO/2-π-density alternation”, which is used to predict susceptibility anisotropics of Fluorobenzenes and Fluoropyridines not yet measured.

The molecular quadrupole moments are calculated from the Zeeman data and compared with the experimental values obtained for various fluorosubstituted Pyridines and Benzenes. If the quadrupole moments perpendicular to the molecular plane are referred to the centers of the six membered rings and are plotted against the number of Fluoroine substituents, nF, the plots closely follow a straight line with identical slopes for the Pyridine- and Benzenefamilies, but with different intercepts at nF = 0. From the “nF = 0 intercept” for the Fluorobenzenes we conclude that the Benzene quadrupole moment proposed earlier by Shoemaker and Flygare should probably be revised
Analysis of the Electronic Factors Controlling the N1s and the First two π (a2, b1) Photoelectron Ionizations in N-Containing Monosubstituted Benzenes (Ph-NRR′ and Ph-N=X)
Authors: Colonna Francesco Paolo , Distefano Giuseppe , Jones Derek , Modelli Alberto
Published: February 2015

The first two π(a2, b1) IE’s, of monosubstituted benzenes containing di- and tri-coordinated nitrogen directly linked to the ring have been measured and analysed together with the N1s IE. These photoelectron properties are found to respond in the same sense, though to different extents, to inductive and mesomeric interactions that the N-containing substituents sustain with the aromatic ring. The different sensitivities of these properties to substituent changes are discussed in connection with mechanisms of transmission of electronic effects with the aid of the ground state electronic structures determined by means of ab-initio calculations. The relative contribution of the relaxation energy to the considered core and valence IE’s is also examined by referring to the model used by Gelius and Siegbahn. The factors determining the apparently anomalous behaviour of nitrobenzene are discussed
A Comparison of Mesquac- and “Full” AB Initio MO-Wavefunctions
Authors: Reibnegger Gilbert J. , Rode Bernd M.
Published: February 2015

The quality of wavefunctions for complex systems derived by either “full” ab initio MO-SCF calculations or within the MESQUAC-MO framework [1] is investigated comparing chemically interesting quantities as atomic and overlap populations and the character of the chemical bond. A direct relation between the results of both methods is shown to exist, allowing an extrapolation of the much less time consuming MESQUAC computations to the “full” MO SCF level. Hydrate complexes of main group and transition metal ions have been chosen for some practical applications
A Note on the Liouville Equation
Authors: Grauel A.
Published: February 2015

We study some geometrical features of the non-linear scattering equations [1]. From this we deduce the Liouville equation. For that we interpret the SL(2, ℝ)-valued elements of the matrices in the scattering equations as matrix-valued forms and calculate the curvature 2-form with respect to a basis of the Lie algebra. We obtain the Liouville equation if the curvature form is equal to zero
On the Mathematical Structure of the New-Tamm-Dancoff Procedure
Authors: Feist W.
Published: February 2015

The New Tamm-Dancoff method is a procedure for the approximate determination of differences of eigenvalues in quantum field theory. This procedure can be formulated mathematically in the framework of the theory of C*-algebras, especially in our case by using von Neumann's infinite tensor products. Calculational rules are presented for operators which obey the canonical anticommutation relations. The concept of the CAR tensor product is introduced for the joint treatment of a system algebra and the associated functional algebra, A conjugation is discussed which will be needed for a proof of equivalence in II.
Molecular Orbital Theory of the Electronic Structure of Organic Compounds
Authors: Grinberg Horacio , Nudelman Norma Sbarbati , Marañón Julio , Sorarrain Oscar M. , Gómez Carlos F.
Published: February 2015

The semiempirical molecular orbital CNDO/S-CI spectral parameterization has been used to elucidate the lower electronic states of a series of dioxodiazacycloalkanes. The a1, b1, and a' occupied molecular orbitals lie predominantly on the oxygen, while a2, b2, and a" are largerly nonbonding orbitals delocalized on the nitrogen and oxygen atoms. The two lowest unoccupied virtual orbitals are predicted to be of b2, a2, and a" symmetry. These orbitals are strongly localized on the C = 0 group. The resulting 1 B2(u0π*) and 1 A2(n0π*) spectroscopic states involve intramolecular charge transfer from the oxygen to the carbon atom of the carbonyl group, which is supported by electron density calculations of these excited states. Although the calculated transition energies may not allow for absolute comparisons with experimental values, it appears that the introduction of self-consistency together with solvation energy and configuration interaction, when the elements of the interaction matrix are properly evaluated, lead to a fairly good interpretation of the singlet-singlet transitions. The lowest energy singlet excited state calculated for each structure is comprised almost entirely of the nπ* configuration.
Untersuchungen über die Chemilumineszenz der Reaktionen von Lithium mit Halogenen
Authors: Neuert H.
Published: February 2015

The chemiluminescent radiation from the reaction of lithium with the halogens Cl2, Br2, I2 and some halogenated molecules has been registered in the visible region. A beam-gas device was used at gas pressures of about 10-2 mb and Li-oven temperatures of 1000-1100K. The spectral lines from the Li atomic states are prevailing. In the Li-SF6 reaction, excitations approaching the ionisation limit of Li are observed. The distribution of the population of the excited states is given for some cases. The mechanism of the reactions is discussed in the light of the corresponding reactions of Na, K, Cs with the halogens, as described in the literature. The participation of the Li-dimer in the reaction processes is evident. No Li-halide fluctuation band structures were found. Strong Li2-A-X-, -B-X- and -C-X-bands appear in nearly all the spectra at higher Li-beam intensities, the excitation of which is discussed. Further molecular bands were observed, emitted from electronically excited states of the halogen molecules Br2 and I2. It is supposed that they are produced by energy transfer collisions mainly from the Li-halide molecules vibrationally excited in their electronic ground state. The appearance of molecular bands from electronically excited states of CuCl and CuBr in the spectra is described.
On the Unified Theory for Non-Equilibrium Phenomena in the Isotropic and Nematic Phases of a Liquid Crystal; Spatially Inhomogeneous Alignment
Authors: Hess S. , Pardowitz I.
Published: February 2015

A nonlinear equation is derived which describes the relaxation of the alignment and the flow alignment in the isotropic and nematic phases of a liquid crystal. In addition to the previously treated case, contributions associated with spatial derivatives of the alignment are taken into account which stem from gradient terms occuring in the free energy (elastic energy) and from the flux of the alignment. Some applications are discussed. In particular, the Leslie and Frank coefficients of the nematic phase are expressed in terms of the equilibrium alignment order parameter and coefficients which are meaningful in both phases
Vibrational Analysis of SnCl4N and SnBr4N
Authors: Sengodan V. , Srinivasacharya K. G.
Published: February 2015

The kinetic constants method is applied to evaluate a fresh set of force constants in case of SnCl4N and SnBr4N, using recent vibrational frequencies. Certain simplifying considerations involving molecular dynamics are made use of in solving the secular equation. The calculated kinetic and force constants are utilised to evaluate other molecular constants, namely mean amplitudes of vibration, Coriolis coupling constants and centrifugal distortion constants. The calculated mean amplitudes of vibration of the Sn-Br bond (SnBr4N) are within the range of the available experimental values (SnBr4)
Zur Bestimmung der optischen Konstanten stark absorbierender Substanzen mit kleinen Probenabmessungen
Authors: Petersenn Alexander v. , Schuster Hans-Uwe
Published: February 2015

To determine the optical constants of small samples a method described by Avery is suitable insofar as it is not necessary to know the absolute value of the reflected intensity of light. The problem of beam-drift during the rotation of the polarizer is solved with a modified experimental arrangement. A computer program for the evaluation of experimental results is outlined. The optical constants of gold as taken from a crystal 0.2 mm in diameter have been measured to check the accuracy of the system
Unimolecular Decomposition of F2SO3- Calculation by Reduced Kassel Integral in Factorized Form
Authors: Jubert Alicia H.
Published: February 2015

The unimolecular decomposition of fluorine fluorosulfonate at 374.2; 384.2 and 394.2 K, is calculated by means of the Reduced Kassel Integral in Factorized Form, an important method developed by J. Troe. The results are compared with those obtained by the RRKM method and experimental work
Lifetime and Hyperfineinteraction in 1P1 States with Nuclear Spin I =1/2
Authors: Liening H.
Published: February 2015

In evaluating the hfs coupling constant A from levelcrossing signals in excited J = 1 states with 7=1/2 where the hfs splitting is smaller than the radiation width, an independent determi­ nation of the lifetime of the state under study is essential. This is demonstrated in the 6s7p 1Pi-state of171 Yb(7 = 1/2). The results are: r(7p *Pi) = 8.9(3) nsec and |^(7p !Pi) | =9(2) MHz.
Influence of Adsorption upon Sound Attenuation in a Tube *
Authors: Križan Peter , Kuščer Ivan
Published: February 2015

flu e n c e o f A d s o r p tio n u p o n S o u n d A t te n u a tio n in a T u b e * Sound waves propagating in a tube filled with gas are attenuated because of absorption in bulk, because of viscothermal effects, and possibly because the gas is adsorbed upon the wall. The latter effect is shown to depend upon a thermal relaxation time, the near-equilibrium desorption rate, and a phenomenological coefficient containing the sticking probability. In case of multilayer adsorption, especially upon metals, this data could be deduced from measurements of sound attenuation. An early experiment by Maurer is discussed in this light.
Electron Spin Resonance of Manganese Nitrate in Diethylacetamide-Water Solution
Authors: Kleinmann V. , Stockhausen M.
Published: February 2015

le c tro n S p in R e s o n a n c e o f M a n g a n e se N i t r a t e in D ie th y la c e ta m id e -W a te r S o lu tio n At small water concentrations, ESR spectra at room temperature exhibit distinguishable con­ tributions which are ascribed to the following ionic species: (I) a small fraction of residual manga­ nese ions with mixed amide-water solvation, (II) amide solvated ions (having altered hyperfine splitting and gr-factor due to nitrate in an outer coordination sphere, so that they may be con­ sidered loose ion pairs), (III) tight ion pair species. Presumably, (II) and (III) are not well defined "chemical" species but constituents of fluctuating aggregations.
Zur theoretischen Interpretation der Anisotropie der 13C-NMR-chemischen Verschiebungen des Ethylens und Benzens auf halbempirischer Grundlage
Authors: Radeglia R.
Published: February 2015

u r th e o re tis c h e n I n te r p r e ta t io n d e r A n is o tr o p ie d e r 13C -N M R -c h e m is d ie n V e rs c h ie b u n g e n des E th y le n s u n d B en zen s a u f h a lb e m p iris c h e r G r u n d la g e On the Semiempirical Theoretical Interpretation of the Anisotropy of 13C n.m.r. Chemical Shifts of Ethylene and Benzene The paramagnetic contribution of the 13C screening constants and their anisotropics are cal­ culated by using localized orbitals and the CNDO/2 method in the molecular orbital description. A comparison of the average energy method for calculating of shielding tensors with the sum-over-states method is performed. It is concluded that the average excitation energy is higher for the screening perpendicular to the molecular plane.
HFS-Measurements in the 4d95p 1P1
0-and 3D1
0 -States of 105Pd (I=5/2)
Authors: Baumann M. , Lauenstein M. , Liening H.
Published: February 2015

The hfs of the 4d95p 1P1
0 -and 3D1
0 -states of 105Pd(I = 5/2) has been investigated by level-crossing spec­ troscopy. From the measurements we get the following hfs coupling constants: A (3D1
0) = - 302 (6) MHz and A (1P1
0) = -220 (6) MHz.
Relaxation and Backscattering of Light Ions in a Semi-Infinite Medium
Authors: Behnel J. , Ecker G. , Riemann K.-U.
Published: February 2015

Relaxation and backscattering of light ions of moderate energy ( ≲ 1 keV) in solid walls are investigated applying the normal Boltzmann equation to a semi-infinite medium, thereby satisfying the exact boundary conditions at the wall surface. Since momentum and energy relax on different scales, Boltzmann's equation is solved in a two scale procedure, treating momentum and energy relaxation separately. Matching the two regions self-consistently yields the ion distribution function and with that macroscopic quantities, e.g. the range distribution and the spectral reflexion coefficient. The application of the method is demonstrated for a simple test model with constant nuclear scattering cross section and no electronic losses.
Electron Diffraction Investigation of the Molecular Structure of Trifluoromethanesulphonic acid (triflic acid)
Authors: Schultz György , Hargittai Istvan , Seip Ragnhild
Published: February 2015

The molecular geometry of triflic acid is characterized by the following bond lengths (rg) and bond angles from an electron diffraction study: S-C 183.3±0.5, F-C 133.2 ±0.2, S=O 141.8±0.2, S-O 155.8±0.3 pm, S-C-F 110.3 ±0.3, F-C-F 108.6 ±0.3, C-S=O 105.4±1.1, C-S-O 102.3 ±2.3, O-S= O 109.9±0.7, and O=S=O 122.0 ±1.3°. The heavy-atom-skeleton is staggered with respect to the rotation about the S-C bond with an estimated barrier of rotation of 15 kJ mol-1.
On the Evaluation of Scalarproducts of Nonlinear Spinorfield State Functionals
Authors: Stumpf H.
Published: February 2015

The metrical structure of the linear state space of a quantized nonlinear field cannot be given a priori. Rather it is determined by the dynamics of the field itself. For the evaluation of state norms and scalarproducts this metric must be known. In functional quantum theory the metrical structure is expressed by the metric tensor G (j) in functional space. Equivalent to the knowledge of G (j) is the knowledge of the set of dual state functionals {|S(j, a)〉} together with the corre-sponding original state functionals {|F(j, a)〉} . In preceding papers attempts were made to calculate G (j). In this paper an approach is made to determine the dual state functionals directly. Equations are derived which have to be satisfied by the dual functionals. The method works in those state sectors which are characterized by real (monopole) particles or monopole ghosts, while it does not work for multipole ghost states. Norm calculations are performed for local monopole fermion states and local monopole boson states of the lepton-quark model derived in a preceding paper.
Liquid Single Crystals of Cholesteric Blue Phases
Authors: Onusseit H. , Stegemeyer H.
Published: February 2015

Liquid single crystals of cholesteric “Blue Phases” (BP) have been prepared and observed by polarizing microscopy. They exhibit a quadratic size without any exception. At the phase transition BP II → BP I a cross-hatching occurs, diagonal to the square sides, indicating a four-fold crystal symmetry. The observed habitus of the BP single crystals clearly evidences a cubic structure of the molecular arrangement. Possible space groups are discussed.
Induced Smectic Phases II. Influence of the Amino Substituent on the Induction of Smectic Phases
Authors: Schneider F. , Sharma N. K.
Published: February 2015

The diagrams of state have been studied for some liquid crystal mixtures which show the induction of smectic phases. Each of the systems studied contains one component with an amino group which influences the polarity and the electron donor property of the molecules. The discussion of the diagrams of state, of the thickness of the smectic layers and of the colours of the mixtures, which indicate the formation of CT complexes, shows that existing models can not explain the induction of smectic phases.
Metastable Transitions in Pyridine and Pyridine Derivatives
Authors: El-Sherbini Th. M. , Migahed M. D. , Shehap A. M.
Published: February 2015

The kinetic energy released in metastable transitions in pyridine, 2, 3, 4 acetylpyridine and 2, 3, 4 aminopyridine differs for the different isomers. This indicates that the dissociation path-way of these compounds depends on the position of the nitrogen atom in the isomer.
Iteration-Perturbation Theory of Covalent Bonding in Crystals
Authors: Krasko Genrich L.
Published: February 2015

Using the theory developed in Part I of this work, the calculations of the total energy, equilib­rium volume, energy gaps and electronic density distributions are performed for magnesium hydride. The predicted equilibrium atomic volume and energy gaps are close to those observed experimentally. The calculations reveal a strong non-homogeneity in the electron density distri­bution. The estimated effective charges of the ions of Mg and H are respectively +1.90 and -0.65 which confirms that the bonding in this compound cannot be considered as a purely ionic one.
Zur semiempirischen Interpretation der Anisotropie des 31P-NMR-Abschirmungstensors von Phosphorylverbindungen / On the Semiempirical Interpretation of the Anisotropy of the 31P NMR Shielding Tensor of Phosphoryl Compounds
Authors: Radeglia R. , Wolff R.
Published: February 2015

The anisotropies of the 31P screening constants of simple phosphoryl compounds X3P=O (X: CH3, Cl, F) are calculated in the molecular orbital description using the CNDO/2 method. The contribution of the π-PO bond order is the reason for the stronger shielding in the direction of the P=O bond.
Centrifugal Distortion and Internal Rotation Analysis in the Ground State of Trans N-Propanol
Authors: Dreizier H. , Scappini F.
Published: February 2015

The ground state rotational spectrum of the trans n-propanol (CH3CH2CH2OH) has been reinvestigated expanding the frequency region, with respect to a previous study, from 8 to 40 GHz. A centrifugal distortion analysis has been carried out by measuring new transitions, including μa- transitions not observed before. The potential barrier V3 to the methyl top internal rotation has been determined from fourteen transitions which were found split into doublets. V3 is 2730 ± 60 cal/mole, ∢(i, a) = 29° ± 1°, assuming Ia = 3.193 uÅ2.
The Influence of Ni on the NMR-properties of 209Bi in Liquid Bi-Ni Alloys
Authors: Ploumbidis D. , Bucklisch R.
Published: February 2015

We present detailed experimental results concerning the temperature and concentration dependence of the 209 Bi-Knight shift and the NMR linewidth in liquid Bi-Ni. The measurements are carried out in an external magnetic field of about 39 KG over the concentration range (0-35) at.-% Ni at temperatures from 400 K to 1300 K. According to our experimental results there are no localized magnetic moments in the liquid Bi-Ni system. The experimental results are discussed in the framework of theories on metallic alloys.
Mass Spectrometric Investigation of Aliphatic Aldehydes
Authors: El-Sherbini Th. M. , Allam S. H. , Migahed M. D. , Dawoud A. M.
Published: February 2015

The mass spectra of C2 to C7 n-alkanals have been measured using a double focusing mass spectrometer. The various reaction mechanisms by which the fragment ions are formed have been elucidated and discussed. Two reactions, the β-cleavage with rearrangement and the y-cleavage reactions lead, respectively, to [C2H4O]+ and [C3H5O]+ ions with significant intensities in butyraldehyde and higher n-alkanals.

The electron energy distribution difference (EDD) method together with a computer programme have been used for evaluating ionization efficiency curves for the molecular ions. The ionization potentials obtained by this method show good agreement with those obtained from other electron impact and photoionization experiments.
X-Ray Diffraction on Electrolyte Solutions in the Low Angle Range
Authors: Pálinkás G. , Kalman E.
Published: February 2015

Aqueous cobalt, nickel, zinc, cadmium and aluminium-chloride, -nitrate, -sulphate and PhAsCl solutions at 25 °C were studied by small angle X-ray diffraction. The scattered intensities of chloride, nitrate and CdSO4 solutions show the so-called "prepeak". The concentration dependence of the peak positions is discussed.
Production of Microcrystallinc Zinc Sulphide at Low Temperatures
Authors: Dafinova R. , Kynev K.
Published: February 2015

The conditions for obtaining zinc sulphide through slow crystallization from a solution with a low concentration of zinc and sulphide ions are investigated in this paper. Electron microscopic studies reveal a tenfold growth of the sulphide crystals as compared to those obtained by the usual precipitation process of passing hydrogen sulphide through a zinc salt solution. X-ray analysis shows their sphalerite structure. The luminophore which was prepared by "cold" activation was of a low intensity and had an emission maximum in the long wave range.
On the Second Moments of the Electronic Charge Distributions in FClCO
Authors: Scappini F. , Guarnieri A.
Published: February 2015

The derivation of some Zeeman parameters for FClCO is reconsidered and the corrected values are reported.
A PPP-investigation of Structural Isomerism in Infinite Polyenes
Authors: Karadakov Peter , Castaño Obis
Published: February 2015

It is shown on the grounds of a semiempirical PPP-treatment that for the equidistant eistrans infinite polyene two types of Hartree-Fock solutions are possible-one yielding a cis-transoid and the other a trans-cisoid distribution of nearest-neighbour bond-orders. Relaxing the nuclear framework according to bond-order magnitudes for the bond-alternation wave (BAW) in the equidistant all-trans polyene, resp. for the two solutions for the equidistant cis-trans polyene mentioned above and using repeatedly the Coulson-Golebiewski formula, realistic self-consistent values of bond lengths have been obtained. The calculated energy differences between the investigated isomers are small, predicting almost equal probabilities. The expressions for the PPPwavefunctions are presented in analytical form suitable for further applications. Long-range Coulomb interactions have been accounted for up to convergence of the groundstate energies.
Weak Mixing in a Quantum System
Authors: Kozak J. J. , Rössler O. E.
Published: February 2015

An analytical solution to the Wigner-Weisskopf problem (an excited two-level atom in inter-action with a radiation field), obtained for both finite-and infinite-length boxes, is re-examined in terms of the qualitative behavior implied. As the equations and the plots of the solutions show, there is a major difference between the behavior of the finite system (with discrete spec-trum) and that obtaining in the large-system limit. In the first case, a pulse-shaped wave "travels down the line" and comes back (and is sent off again) many times, completely "losing its shape" in the process (and subsequently re-gaining it on a much longer time scale infinitely often, due to the presence of a Poincare recurrence). In the large-system limit, on the other hand, a delta-impulse-like wave travels down the line only once (in finite time), and there is also no loss of shape upon its return after infinite time. Thus, there is no longer any even temporary "smearing out" of the initially sharply localized energy, and hence no "mixing" in the intuitive sense of the word. Nonetheless a dense spectrum is found (similarly as in the distribution theoretical case of an isolated delta-impulse in an infinite domain), and hence weak mixing in the sense of Lebowitz. The contradiction can be resolved at the expense of having to abandon some symmetry: by assuming the atom adjacent to two cavities of incommensurate lengths. Then the infinite system limit is unchanged (no return in finite time), but the transition is characterized by intuitive mixing of increasing effectiveness.
Imperfect Bifurcations and Spatial Structures in Dissipative Systems
Authors: Hlavacek V. , Janssen R. , Rompay P. Van
Published: February 2015

One-dimensional reaction-diffusion equations associated with the trimolecular model of Prigogine and Lefever ("Brusselator") are analyzed. A physical description of possibilities of keeping con-centrations of initial components constant is discussed. It is shown that the problem considering diffusion of initial components gives rise to an imperfect bifurcation problem. The diffusion equa-tions have been solved numerically by a continuation procedure for the fixed and zero flux boundary conditions. The analysis indicates that the models including diffusion of all reacting components do not admit an occurence of trivial solutions. These models, as a result, also exclude the pos-sibility of primary bifurcations. The models which consider diffusion of the initial components suppress the number of possible solutions of governing equations. These models may also predict both symmetric and asymmetric states. Apparently this type of models is more suitable for predic-tion of patterns of spatial organization in growth. Since the number of possible profiles is strongly reduced this principle may lead to a more deterministic way of an evolution process. Symmetric profiles occuring on an isola cannot be reached by an evolution process unless a large perturbation is imposed on the system.
Wavelength Dependent and Adiabatic Photochemistry of Endoperoxides of Aromatic Hydrocarbons
Authors: Schmidt R. , Drews W. , Brauer H.-D.
Published: February 2015

The photochemical cleavage of the endoperoxides of anthradichromene and benzodixanthene into the parent hydrocarbon and oxygen is shown to be an adiabatic photoreaction originating from an upper excited singlet state. This photochemical behaviour is described by a theory for the photochemistry of endoperoxides developed by Kearns and Khan.
Molekülinterne Dipolorientierung und dielektrische Absorption in verdünnter Lösung bei Mikro- und Submillimeter-Wellen. I. Primäre Amine / Intramolecular Dipole Reorientation and Dielectric Loss of Microwaves and, Submillimetrewaves in Diluted Solution I. Primary Amines
Authors: Klages G. , Wieczorek E.
Published: February 2015

The dielectric loss of very diluted solutions of four aromatic and three aliphatic amines in three non polar aliphatic solvents at 20 °C has been measured. The wave numbers cover 0.1 to 200 cm-1 . It is shown, how to analyse the microwave spectra of the loss factor ε″ in terms of three absorption areas, two of Debye relaxation type and the high frequency one of Lorentz resonance type. To limit the latter at its high frequency side, the extinction coefficient a has been used to determine and separate the lowest molecular resonances. From the analysis, dispersion steps and the components of the dipole moment due to the three absorption regions are calculated. Comparison with the so called optical dispersion step insures within the limits of experimental error that the absorption due to orientation of the permanent dipole moment is covered by the measured band. The long wave region belongs to the rotation of the molecules, the two others to intramolecular reorientation. In aromatic amines not all molecules of the sample are able to invert their NH2 group, but slower orientation by hindered inversion happens. On the other hand, in aliphatic amines the group is rotating and the high frequency region may be due to Foley absorption.
Molekülinterne Dipolorientierung und dielektrische Absorption in verdünnter Lösung bei Mikro- und Submillimeterwellen. IL Sekundäre und tertiäre Amine / Intramolecular Dipole Reorientation and Dielectric Loss of Microwaves and Submillimetrewaves in Diluted Solution II. Secondary and Tertiary Amines
Authors: Klages G. , Wieczorek E.
Published: February 2015

Supplementary to a preceding investigation on primary amines, the dielectric loss increments of three aromatic dimethylamino compounds, diphenylamine, N-methyldiphenylamine and triphenylamine, and of dicyclohexylamine have been measured in very diluted solutions at 20 °C. The loss data resulting from 0.1 up to 250 cm-1 are now covering the complete absorption region due to reorientation of the permanent molecular dipole, especially that part based on inversion. To resolve this part, the absorption curves are analysed in terms of three areas using the same method as done for primary amines. By this the dipole components assigned to the special reorientation processes may be discerned and discussed. So the dipole component of the dimethylamino group which reorientates by intramolecular motion is smaller than that of the amino group. The occurrence of an inversion process is demonstrated, but the molecular dipole component governing it also may reorient more slowly as the result of a hindered inversion. The additional reorientation of a mesomeric moment by twisting of the phenyl groups is suggested in triphenylamine and in the diphenyl compounds. The aliphatic dicyclohexylamine only shows a Poley absorption area, increased perhaps by intramolecular libration.
The Chemla Effect in the Internal Mobilities of (Li-NH 4 )N0 3 Melts
Authors: Okada Isao
Published: February 2015

Internal mobility ratios in melts of the system (Li-NH4)NO3 were measured with the Klemm method. Densities and electric conductivities of this system were also measured. From these data the internal mobilities bLi and bNH⁴ were calculated. On account of the inevitable thermal decomposition of NH4NO3 the range of temperatures and concentrations was limited. In these the mobility of NH4
+ is considerably greater than that of Li+. In contrast to other binary nitrate systems, the isotherms of the internal mobility of the larger cation distinctly decrease with a decrease of its concentration, in which the fact that NH4NO3, whose cation is moderately light though large in size, melts at relatively low temperature is reflected. The isotherms of bLi and bNH⁴ and the temperature dependence are discussed on the basis of the autor’s interpretation so far presented.
Exzeßenthalpien und Solvatationsverhalten der Systeme LiBr/Methanol, ZnBr2/Methanol und LiBr/ZnBr2/Methanol
Authors: Christahl M. , Thönnissen J.
Published: February 2015

For the binary systems Li Br/methanol and Zn Br 2/methanol as well as for the ternary system Li Br/Zn Br 2/methanol the integral enthalpies of mixing are experimentally determined. The mixing of Li Br and methanol is more exothermic than in the case of Zn Br 2. The excess enthalpy is largest for the ternary system. From the mathematical approximation of experimental data the differential enthalpies of solution and of dilution are obtained. In the discussion it is concluded that in diluted solutions the salts are surrounded by a strongly coordinated inner solvation sphere (coordination number N = 4) and a less coordinated outer solvation sphere (N = 6) resulting in a total solvation number of N = 10.
Superfluorescence from Chemically Pumped Iodine Molecules
Authors: Stephan-Rossbach K. H. , Comes F. J.
Published: February 2015

Stimulated emission from chemically formed excited iodine molecules has been observed. The emission originates from the vibrational state ν′ = 55 of I2(B 3 II). The excited molecules are produced by a three body recombination reaction.
The Response of CO2 Evolution from Soils to Global Temperature Changes
Authors: Schleser G. H.
Published: February 2015

Own experiments and literature data point at a strong correlation between mineralization processes in soils i.e. the corresponding CO2 release and temperature variations. This seems to be important with regard to the global CO2 problem, since it implies that due to the global temperature increase over 80 years (1860-1940) large additional amounts of CO2 were released to the atmosphere. These additional quantities seem to have been at least as important as the anthropogenic release of CO2 from the burning of fossil fuels.
Adiabatic Potentials and Oscillator Strengths of Thallium-Noble Gas Atom Pairs
Authors: Czuchaj E.
Published: February 2015

Baylis' semiempirical method has been applied for calculating interatomic potentials and oscillator strengths as a function of internuclear separation of the thallium-noble gas systems. The new potentials for the four lowest molecular states of each diatomic have been compared with the corresponding ones deduced by Cheron et al. from the measurement of continuum emission intensities on the extreme wings of the Tl resonance lines due to noble gas perturbers. The calculated potentials differ considerably from the latter ones. The molecular oscillator strengths have been calculated for both the allowed and the forbidden Tl transitions. The asymptotic values of the first ones are compared with the corresponding atomic oscillator strengths of other calculations and measurements. The agreement is generally quite good.
Infrared Microwave Double-Resonance Investigations on Trifluoromethyljodide (CF3I)
Authors: Ibisch E. , Andresen U.
Published: February 2015

An additional set of infrared microwave double-resonance signals was observed using the 9 R 12 line of the CO2 laser. The vibrational transition involved is assigned to the QQs(8) transition of the v1-fundamental. ⊿J = 1, K = 5 rotational transitions were found for J = 5, 6, 7, and 8 in both vibrational states. A detailed description of the apparatus and methods is given.
Die Valenzisomerisierung des 9.10-Dewarisomers zum 9-t-Butylanthrazen
Authors: Jahn Burkhardt , Dreeskamp Herbert
Published: February 2015

By DTA calorimetry the enthalpy of valence isomerization of 1-t-butyl-dibenzo-2,5-bicyclo-(2,2,0)-hexadiene (9-t-butyl-9,10-Dewar-anthracene) 2 to 9-t-butylanthracene 1 has been determined as -172±5 kJ mol-1 in decaline at 350 K. Photochemically the isomerization 2→1 occurs with the high quantum yield of ΦR≅O.4 in contrast to the low quantum yield of the reverse photo-isomerization 1→2 of ΦR = 0.016 [5]. Since other meso-substituted anthracenes, e.g. 9-methyl-anthracene or 9-trimethylsilyl-anthracene do not photoreact to Dewar-isomers, it is concluded that a deformation of the anthracene sceleton is a prerequisite for this type of valence isomerization.
Schwingungseigenschaften des PO4
3-Ions im Monazit-und Zirkon-Gitter
Authors: Baran Enrique J. , Lavat Araceli E.
Published: February 2015

The force constants and mean amplitudes of vibration for the PO4
3- ion present in the lattices of the rare earth orthophosphates of the monazite and zircon types, have been calculated from recently reported Raman data. It is shown that the P-O bond strength depends not only on the overall unit cell contraction but also on the structural type.
Infrared-Radio-Frequency Two-Photon Investigations on Deutero-Fluoroform (CDF3)
Authors: Ibisch E. , Andresen U.
Published: February 2015

Some rotation-vibration transitions of the v5-band of Deutero-Fluoroform using the infrared-radio-frequency two-photon technique are reported. An absorption cell for infrared-radio-frequency or infrared-microwave two-photon and double-resonance measurements inside a CO2 laser cavity is described. This type of cell may be used in a wide frequency range.
Checking Plane Wave Approximation for Double Crystal Topography with Curved Samples
Authors: Jenichen B. , Jenichen B. , Molding W.
Published: February 2015

The double crystal diffractometer in n,-n position realizes plane wave conditions only approximately. Nevertheless topographs taken with such arrangements are usually interpreted on the basis of contrast simulations starting with plane waves. Observations of diffraction patterns obtained with curved samples in an n,-n setting have lead us to study the validity of such a treatment. Simulations made for different types of the starting wave actually show that plane waves are adequate even in that critical case. However for a full coincidence between simulation and experiment it proved necessary to account for the residual angular spread within the collimated beam by averaging several plane wave simulations.
Theoretical and Experimental Study of the Diffraction Contrast on Magnetic Domain Walls
Authors: Polcarová M. , Brádler J.
Published: February 2015

Dynamical theory of the X-ray diffraction on a crystal containing misfit boundary was applied to the interpretation of the contrast observed in X-ray topographs on 90° magnetic domain walls in single crystals of an Fe-Si alloy. The integrated intensities were computed for several cases corresponding to the actual conditions of experiments. Good agreement of theoretical and experi­mental results was obtained.
Oxidation Induced Anisotropic Deformation in Perfect Si Crystals. Dynamical X-Ray Diffraction Study
Authors: Burgeat J. , Caciuffo R. , Primot J. , Rustichelli F.
Published: February 2015

Double X-ray diffractometry has been used to investigate perfect Si crystals of different orientations, on which SiCO2 layers of different thickness were grown. For the (111) and (110) orientations no appreciable modification of the theoretical diffraction pattern is observed. An important modification, which depends on the SiO2 thickness, appears however for the (100) orientation. The observed effect does not change when the SiO2 is removed and can be interpreted as an enhancement of the lattice parameter.
White Synchrotron Radiation Topography of (11̄0) Nickel Single Crystal
Authors: Stephenson J. D.
Published: February 2015

Changes in 70.53° magnetic domain structure on the surface of a perfect (11̄0) nickel crystal have been observed using white synchrotron X-radiation topography. The crystal was influenced by a variable [11̄0] magnetic field. At field strengths ≿ 100 A/m [111̄]-spike domains, thought to be traces of [011], 70.53° (oblique) magnetic domain walls, appeared within [111]-bands (0.4 mm wide) in the topographs. Reversal of the field produced similar spikes at equivalent field values but in different regions of the crystal.
Superposition Model Analysis of the Spin Hamiltonian Parameters of Two Gd3+ Doped Thorium Dichalcogenides
Authors: Amoretti G. , Fava C. , Varacca V.
Published: February 2015

The spin Hamiltonian parameters of Gd3+ in a single crystal of Thorium disulfide (ThS2) are analysed by means of the superposition model, in its most general form of a two exponents power law. In fact, the approximated one exponent power law is not suitable for this compound, where the ion-ligand distances show a quite large spread. The results of the analysis are then applied to the case of Gd3+ doped Thorium oxysulfide (ThOS), where the fitting of the experimental data is possible only assuming some distortion of the ligand cage.
On the Theory of the Magnetic Resistivity near a Ferromagnetic Phase Transition
Authors: Lage E. J. S.
Published: February 2015

Perturbation theory is applied to the evaluation of the magnetic resistivity of a magnetic metal near a ferromagnetic phase transition. The method starts from first principles and uses diagrammatic expansions together with the theory of spin cumulant averages. Emphasis is put on some critical hypothesis regarding the behaviour of the coupled electron-spin system. A generalization of the de-Gennes-Friedel expressions for the static conductivity is derived and arguments are advanced regarding its energy like critical behaviour.

A short discussion is also given for the frequency dependent conductivity and it is shown that it deviates from Drude’s law.
Cumulative Rapidity Gap-distribution and Cluster Characteristics in Proton-emulsion Interaction at 300 GeV/c
Authors: Ghosh Dipak , Roy Jaya , Sengupta Kaushik , Naha Sadhan , Basu Madhumita , Guhathakurta Tarit , Bhattacharjee Anuradha
Published: February 2015

Multiparticle rapidity clustering in proton-emulsion interactions at 300 GeV/c is studied using cumulative rapidity-gap distributions. Both 2-particle and 3-particle clusters have been observed.
EXAFS Spectroscopy with Amorphous Transition Metal-Metalloid Alloys
Authors: Schmückle Friedrich , Lamparter Peter , Steeb Siegfried
Published: February 2015

EXAFS measurements were performed with amorphous T80M20 (T=Fe,Co, Ni; M=B,P). For the interpretation of the EXAFS spectra it was necessary also to compare them with spectra obtained from crystalline specimes with known atomic arrangement and with similar chemical composition such as the alloys Fe2B, CO3B, Ni3B as well as Fe3P, CO3P, and Ni3P. As a radiation source the Ag-target of a rotating anode X-ray generator (6 kW) was used. The spectra were obtained using a flat LiF-(220) monochromator. The specimens were kept at 80 K and thus thermal effects could be reduced. The EXAFS spectra of the amorphous alloys and those of the corresponding crystalline compounds of the type T3M show among each other a relatively great similarity. The greatest similarity exists in the case of the Ni-and Co-alloys. The amorphous alloys based on iron however show larger discrepancies with respect to the corresponding crystalline ones, where the greatest deviation occurs with the compound Fe2B. The Fourier transforms show such similarities too. The EXAFS spectra of the crystalline elements Fe. Co, and Ni as well as their Fourier transforms evidently show differences compared to the amorphous specimens and to the T3M compounds.

The similarities observed between the amorphous alloys and the corresponding crystalline specimens of the T3M-type together with their large discrepancies with respect to the pure metals led to the conclusion that the local structure in the amorphous alloys is in considerable accordance with that of the corresponding T3M-compound.