bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Thermal Behaviour of the n·C13-n·C20 Lithium Soaps
Authors: Franzosini P. , Sanesi M. , Cingolani A. , Ferloni P. 
Published: February 2015

Abstract
The phase transition temperatures and enthalpies were determined by differential scanning calorimetry between room temperature and the isotropic liquid region for the lithium n.alkanoates from tridecanoate to eicosanoate. The number and nature of the phases involved were discussed in comparison with the literature data available for some of the homologues concerned. For diffe-rent kinds of transitions, the significant features of the plots AS vs. number of carbon atoms were put into evidence.
Konformation konjugierter Cyclopropanderivate mit sterischer Hinderung / The Confirmation of Cyclopropane Derivatives with a Rotation Barrier
Authors: Al-Nia'mi Rajiha I. , Shanshal Muthana 
Published: February 2015

Abstract
The influence of α- and o-methyl substituents on the conformation of phenylcyclopropane is studied. Synthesis as well as low temperature PMR studies of the corresponding derivatives are carried out. The changes in the PMR spectra measured at room temperature and -100 °C are too small to count for the rotation barrier calculations. Fo 2,2-dichloro-1-phenyl-cyclopropane (8) ,2,2-dichloro-1-methyl-1-phenyl-cyclopropane (9) and 2,2-dichloro-1-o-tolyl-cyclopropane(10) the predicted most stable conformation is the near-bisected in which the aromatic ring is slightly twisted towards the CI atoms. For 2,2-dichloro-1-(2,6-dimethyl-phenyl)-cyclopropane (11) the planar conformation is predicted to be most stable. MINDO/3-FORCES calculations of the conformations and rotation barriers of similarly methylsubstituted vinyl-cyclopropanes, phenylcyclopropane and 2-cyclopropyl-pyridine are reported. It is found that introducing a methyl group to the a-position of the three membered ring or to the C4 atom f the vinylgroup causes the deviation of the olefine plane from the bisected conformation by 30°. Similar deviations are expected for the α-and o-methyl-phenylcyclopropanes.
Quarks im Lichte einer Idee von Pais
Authors: Bopp Fritz 
Published: February 2015

Abstract
A wave equation of a kind proposed by Pais in 1953 describes a particle with an infinite sequence of quantum states, which belong to the symmetrical representations (λ, 0) of the group SU 3. Particles composed of such single ones are connected with the whole set of representations (λ, μ) of SU 3. The wave equation is compatible with an exclusion principle. Assuming that only particles with zero triality occur, all quarks and quarklike particles are excluded. Neither coulours, nor bags are needed, as we do not need repulsive forces to exclude Li-atoms with symmetrical wave functions.
Emission Spectra of Crystal Phosphor BaCl2-Pb
Authors: Tabakova Veneta , Kynev Kyncho 
Published: February 2015

Abstract
Emission spectra of Pb2+ centres in barium chloride single crystals have been studied between 4 and 300 K by excitation with different wave lengths. Excitation spectra at 300 K have also been obtained by measuring the emission in the maxima of the shoitwave and longwave bands. The results allow to conclude that the high energy emission band is due to the transition | 3T1u > → | 1A1g > in the activator ion. The more effective excitation of the low energy emission band observed in the shortwave region of the absorption spectrum and the complex nature of both bands are discussed.
Routes to the Formation of Association Products in CO2 from Reactions of CO2 · CO2
+ Ions with Several Neutral Molecules
Authors: Rakshit A. B. , Warneck P. 
Published: February 2015

Abstract
The reactions of CO2·CO2
+ ions with SO2 , O2, C2H2, COS, NH3, and CS2 have been re-investigated to determine the yields of products of the type CO2·A+ , where A is the neutral reactant molecule. The same products are also formed by third body attachment of A2
+ to CO2 . In addition, A2
+ cluster ions are observed in several cases. Rate coefficients for these reactions are given.
On the X-ray Scattering Factor of Metallic Lithium in the Long-Wavelength Limit: The "Solid State Effect"
Authors: Visser E. G. , Geertsma W. , Lugt W. van der , Hosson J. Th. M. de 
Published: February 2015

Abstract
By considering three successive approximations to the conduction-electron wavefunction of metallic lithium, it is shown that the X-ray scattering factor at small wavevectors is very sensitive to the model chosen for describing the electron density. It is demonstrated that, when screened pseudopotentials are used, the "solid state effect" is almost negligible in this region of wave-vectors.
Haloalkane-Aromatic Complexes in the Ground and Excited States Molecular Orbital Calculation
Authors: Brinn I. M. 
Published: February 2015

Abstract
CNDO/2 calculations have been carried out on a series of haloalkane-aromatic 1: 1 complexes in the ground and first excited singlet states and one 2 : 1 complex in the ground state. Calculated stabilities agree very well with reported experimental results for the ground state. Our calculations indicate that the substituent effect on complex stability in excited states will be the opposite of that found for the ground state.
Versuche zur Berechnung der Fluoreszenzspektren organischer Farbstoffe
Authors: Fabian Walter 
Published: February 2015

Abstract
Attempts to Calculate the Fluorescence Spectra of Organic dyes Within the scope of the PPP-approximation a β-variation procedure is used to calculate the fluorescence spectra of some organic dyes and to estimate geometry changes upon excitation into the fluorescent state.
Note on a Topological Property of the HOMO-LUMO Separation
Authors: Gutman Ivan 
Published: February 2015

Abstract
The effect of cycles on the HOMO-LUMO separation of alternant conjugated hydrocarbons is examined. A general topological regularity is established, namely that (4m + 2)- membered conjugated circuits increase and (4w)-membered conjugated circuits decrease the HOMO-LUMO separation. Möbius cyclcs exhibit an opposite effect.
Magnetic Field Instability of a Plasma in a Beam of Electromagnetic Radiation
Authors: Gradov O. M. , Stenflo L. 
Published: February 2015

Abstract
A beam of electromagnetic radiation can generate magnetic fields in plasmas. It is shown that those fields grow significantly when the incident radiation is sufficiently strong. We obtain expressions for the characteristic time of the growth of the fields as well as for their spatial distribution and point out a possible mechanism, which can lead to the formation of a quasi-stationary state. The maximum value of the magnetic field strength is estimated
The Millimeter Wave Rotational Spectra of Carbonyl Sulfide
Authors: Dubrulle A. , Demaison J. , Burie J. , Boucher D. 
Published: February 2015

Abstract
The following rotational spectra of carbonyl sulfide have been accurately remeasured with a beam-absorption spectrometer:

16O12C32S in the vibrational ground state and in the vibrational state 0 11 0.

16O12C34S in the vibrational ground state.
The ground state spectra of the following isotopic species have been measured with a video spectrometer:

17O12C32S, 18O12C32S, 16O13C32S, 16O12C33S, 16O12C36S, and 16O13C34S.
Our measurements have enabled us to improve the molecular constants notably for these cases.
Network Structure of a System coded by Groups
Authors: Busse H. G. , Havsteen B. H. 
Published: February 2015

Abstract
A system may be characterized by its dynamics as well as by its structure. Several kinds of schematic drawings have been proposed to represent the structure of a system. Here, the representation of the structure by free groups is discussed. Free groups are an abstract mathematical tool, which permits the systematic treatment of a structure. The suggestion is exemplified by its application to a chemical kinetic model. The structure of the model is given (coded) by a linear sequence of symbols. The interaction of the environment with the structure (mutation) and the relation between structure and systemic boundaries (finiteness) are treated. The concept probably also applies to biological systems. Also, context-free languages could be used as alternate representations of system structures.
Microwavc Spectra of 3-Cyanotliiophene-34S and 3-Cyanothiophenc-15N and Partial r0-restructure
Authors: Wiese J. , Schwarz R. , Sutter D. H. 
Published: February 2015

The rotational spectra of 3-Cyanothiophene-15N and 3- Cyanothiophene-34S were analyzed in the frequency range between 10 and 25 GHz.
A partial r0-restructure was fitted to the observed rotational constants. The cavity-Fourier-transform microwave spectrometer with pulsed supersonic nozzle beam gas injection is proposed as a promising tool to investigate the rotational spectra of vibrationally excited moleculs (ν̄vib ⪞ 800 cm-1).
Investigation of Rotational Relaxation by Double Resonance and Stark Switch Techniques
Authors: Schrepp W. , Dreizler H. , Guarnieri A. 
Published: February 2015

Abstract
For the four rotational levels JK₋K₊ = 101, 110,212 and 221 of ethylene oxide all possible four level double resonance experiments for dipole allowed transitions have been performed to investigate collisional effects and to determine the relative change of signal intensity, η = ⊿I/I, due to high power pump radiation. The T1 and T2-relaxation times have been measured for all dipole allowed transitions within these four levels.
A combination of the data obtained from both experimental methods allows the determination of rate and bath constants taking into account only first order dipolar transitions. No further restrictions have been used. This approximation is supported by a triple resonance experiment.
In addition to the pure gas investigation in the absence of external fields, rotational relaxation has been studied in the presence of a static electric field and in a mixture with hydrogen.
Alkali-Halide Chemiluminescence: Studies on the Fluctuation Bands from some Alkali (Li, Na, K)-Halogen (CI, Br, I)-Reactions
Authors: Roeder M. 
Published: February 2015

Abstract
Molecular chemiluminescence spectra from selected alkali-halogen reactions are presented using a beam-gas arrangement operating with pressures between 10-1 mtorr (single collision conditions) up to 10 mtorr in the reaction zone. Spectra are presented for the chemiluminescent reactions M2 + X2->MX* + MX, where M2 = K2, Na2 and X2 = Cl2, Br2, I2. The MX* emitter is identified by comparison with previous absorption and emission studies of these molecules. The sodium reaction with I2 as well as all lithium reactions with different halogens (Cl2, Br2, I2) do not yield appreciable molecular emission. The differences in molecular chemiluminescence intensities among this type of reactions can be understood in terms of the Landau-Zener formalism for an electron jump and turn out to be consistent with the results from measurements on absorption, emission and dissociation.
Notizen: A Note on the Off-Diagonal Elements of the Density Matrix in Thermal Equilibrium and Thermal Radiation
Authors: Sutter D. H. 
Published: February 2015

Abstract
A closer look at the off-diagonal elements of the density matrix of a thermal gas phase molecular ensemble reveals, that they lead to a contribution to thermal radiation which increases in power proportional to the number of particles. A quantitative comparison of this contribution to the one originating from spontaneous emission is given.
Phonon Dispersion in Noble Metals
Authors: Agarwal R. M. , Rathore R. P. S. 
Published: February 2015

Abstract
A new lattice dynamical model comprising various interactions among the constituents of noble metals is developed. The model assumes central core-core coupling extending to the first neighbours only. Overlap interactions among neighbouring d-shells are expressed in terms of an angular parameter. Volume interactions for core-conduction electrons and d-shell-conduction electrons are described through a simple expression. Interactions between core and d-shell are also accounted for adequately.
The lattice is considered in equilibrium under the volume dependent energy of cores, conduction electrons and the d-shell electrons. The obtained dispersion relations for copper and silver are compared with (a) experimental data, (b) results of a recent first-principle calculation and (c) results of a recent phenomenological study.
Structure Analysis of Vacuum-Deposited Mg Thin Films
Authors: Haider N. C. 
Published: February 2015

Abstract
Thin films of Mg, in the thickness range of 23,000 ~ 93,000 Å, were prepared at 10-6 Torr pressure and 45° C temperature. The x-ray diffraction spectra (XDS) have been measured for several reflections with crystal monochromated and Ni-filtered CuKα1 radiation. A detailed Fourier analysis of the broadening of x-ray lines indicated very strong effects of the oxidation of the surface, thermal stress along 100 and 002 planes, and preferred orientation along 002 planes parallel to the surface of the substrate.
Annihilation of Positrons in Rare Gases — A Phenomenological Study
Authors: Grover P. S. 
Published: February 2015

Abstract
The life time, λ, of positrons in rare gases under the simultaneous influence of a steady magnetic and an alternating electric field is studied. λ depends on the frequency and attains a maximum when the frequency equals the cyclotron frequency. The extent of this dependence is quite sensitive to the positron atom momentum transfer rates.
Dynamische ESR-Untersuchungen zur Propellerform der Triphenylmethylgruppe
Authors: Scheffler K. , Digel F. , Krieg R. , Stegmann H. B. 
Published: February 2015

Abstract
The ESR spectra of substituted 4-oxyl-3,5-di-tert.butyl-benzyl-triphenylmethyl radicals ex-hibit the expected temperature dependence of the methylene protons, which is explained by internal hindered rotation of the phenoxyl ring. Furthermore, alternating linewidths have been observed. This phenomenon can be assigned to a two jump process between right-and left-handed propeller shapes of the triphenylmethyl substituents. The activation enthalpies depend on the sense of rotation of the phenyl groups and are found to be around 14.3 and 32.6 kJ/mol. Obviously the propeller shaped form of the triphenylmethyl group is due to steric reasons.
Cross Sections for Depolarization of 62P3/2 Cesium Atoms Induced in Collision with Noble Gases from D2 Optical Pumping
Authors: Rudedcki P. 
Published: February 2015

Abstract
Possibilities of examing the relaxation of alkali atoms in 62P3/2 state by analysing the pumping process with a weak circularly polarized D2 line are presented. Results of an experiment on Cs-He and Cs-Ne systems have also been given. Assuming the J-randomization model for relaxation of alkali atoms in 2P3/2 state and neglecting energy transfer between 62PJ states, we obtained the cross sections for relaxation: Cs-He, 62.6 ± 10.0; Cs-Ne, 54.0 ± 9.0; in 10-16 cm2 units.
Enthalpy of Formation of Gallium-Germanium-Tin Liquid Alloys: Evaluation of the Liquidus Surface of the Phase Diagram from Excess Functions of Mixing
Authors: Fornaris M. , Muggianu Y. M. , Gambino M. , Bros J. P. 
Published: February 2015

Abstract
With a differential high temperature Calvet calorimeter, the enthalpies of formation of Ga-Ge-Sn liquid alloys have been measured at 703, 798, 895, 1000 and 1230 K in the whole concentration area. The experimental results are compared with those obtained by using an interpolation relation on the basis of the excess functions of mixing of the bordering binary systems. The interpolation relation is used to calculate the partial excess functions and to determine the position of the liquidus surface of the Ga-Ge-Sn phase diagram: the experimental and calculated values agree fairly.
The Effect of Particles on Blast Waves in a Dusty Gas
Authors: Higashino Fumio , Suzuki Tateyuki 
Published: February 2015

Abstract
The effect of suspended particles on cylindrical blast waves is investigated by making use of a series expansion method with respect to 1/M2 take off [2], where M is the shock Mach number. Velocity and temperature equilibrium between the gas and the particles is assumed. As a result, one finds that the particles are assembled near the shock front and that behind it the slopes of the pressure and velocity profiles increase, as the volume fraction of particles increases. The difference between the zeroth and first order solutions becomes the smaller, the larger the volume fraction of the particles. The decay rate of a blast wave in a dusty gas is greater than in a dust-free gas.
Ne Emissions from a He Discharge Flow System: I. Relative Transition Probabilities of Ne
Authors: Haak H. K. , Zetzsch C. , Stuhl F. 
Published: February 2015

Abstract
A windowless microwave discharge in He was used to generate Ne emissions in a flow system. Relative transition probabilities for a number of emission arrays were determined from the observed line intensities. Agreement is generally obtained with previous experimental and theoretical work.
Population Analysis with Hydrogen 2 p Polarization Functions Included in the INDO Basis Set
Authors: Facelli J. C. , Contreras R. H. 
Published: February 2015

Abstract
Mulliken population analysis with 2p polarization functions included in the AO basis set of the INDO method has been performed for a set of molecules containing hydrogen as well as first row atoms. It is found that this enlargement of the basis set yields an increasing electron population in hydrogen atoms, in agreement with trends found in “ab initio” methods.
X-Ray Diffraction Study of a Concentrated Al(NO3 )3 Solution
Authors: Caminiti R. , Radnai T. 
Published: February 2015

Abstract
The scattering of X-rays from a concentrated Al (NO3)3 aqueous solution has been measured and analyzed at 25 °C. Good agreement with experimental data is achieved through a model in which Al3+(H2O)6 interacts with twelve water molecules through short and linear H-bonds. The water molecules which are the nearest neighbors to the Al3+ ions have trigonal orientation and each 0 atom in the nitrate ion gives rise to about 2 weak hydrogen bonds with water molecules.
Untersuchungen zur Anwendbarkeit semiempirischer SCF-Verfahren zur Behandlung von Tautomerieproblemen heterocyclischer Verbindungen/ Investigations on the Applicability of Semiempirical SCF-methods for the Treatment of Heterocyclic Tautomerism
Authors: Fabian Walter 
Published: February 2015

Abstract
Using hydroxy substituted 1,5-naphthyridines as examples various semiempirical SCF methods are tested for their applicability in heterocyclic tautomerism. It is shown that even in cases where the MINDO/3 method yields only insignificant results it is possible to get information upon tautomeric equilibria by a comparison of experimental UV spectra and excitation energies as calculated by the CNDO/S-CI method.
Notizen: Strömung von nematischen Flüssigkristallen in Kapillaren mit rechteckigem Querschnitt /The Flow of an Nematic Liquid Crystal in a Capillary with a Rectangular Cross Section
Authors: Schneider F. 
Published: February 2015

Abstract
The velocity profile for the flow of an incompressible nematic liquid crystal in a capillary with a rectangular cross section is calculated. Equations for the determination of the different viscosity coefficients from the volume flow rate and the pressure difference are presented.
Cation and Anion Reorientation at Phase Transition in Pyridinium Tetrafluoroborate
Authors: Wąsicki J. , Pająk Z. , Kozak A. 
Published: February 2015

Abstract
Temperature dependences of 1H and 19F second moment and spin-lattice relaxation times for polycrystalline pyridinium tetrafluoroborate were measured. A phase transition was discovered at 202 K. A model of cation reorientation between inequivalent (low-temperature phase) and equivalent (high-temperature phase) equilibrium positions is proposed. Whether the anion reorients isotropically or about a symmetry axis cannot be decided. An analysis of cross-relaxation effects yielded activation parameters for cation and anion reorientation. The rotational correlation times for both ions converge just at the phase transition reaching the value of 10-10s.
Electrostatic and Packing Contributions to the Structure of Water and Aqueous Electrolyte Solutions
Authors: Holovko M. F. , Kalyuzhny Yu. V. , Heinzinger K. 
Published: February 2015

Abstract
The role of electrostatic and packing contributions to the structure of water and aqueous electrolyte solutions has been investigated by the comparison of results of Molecular Dynamics simulations with those of analytical calculations for the corresponding Lennard-Jones systems. It is demonstrated that the electrostatic interactions play a dominant role in determining the characteristic data of the various radial distribution functions in the solutions, although their relative importance decreases with increasing pressure, temperature, and ionic concentration. It is proposed that for the analytical treatment of hydrogen bonded liquids the total potential should be subdivided into three regions - short range repulsion, potential minimum, long range electrostatic interactions - and a different theoretical approach should be employed for each region
Spontaneously Twisted Nonchiral Nematic Liquid Crystals
Authors: Chrzanowska A. 
Published: February 2015

Abstract
Nematic liquid crystals exhibiting a negative K2 elastic constant are discussed on the basis of a microscopic model potential. Stability conditions are satisfied by taking into account higher order terms in the expansion of the free energy. A continuous Freederiks effect is predicted for systems with negative K2.
Ionization of Liquid Tetramethyl Germanium by 60Co-γ-Radiation
Authors: Lopes I. , Schmidt W. F. 
Published: February 2015

Abstract
The ionization current produced in liquid tetramethyl germanium by 60Co-γ-radiation was measured with a guard ring type, parallel plate ionization chamber. The yield of ion pairs as a function of the applied electric field strength was determined and the free ion yield without applied electric field was obtained to be Gfi (0) = 0.68 ±0.10.
First Evidence of Self-Organized Criticality in the Impact Ionization Breakdown of Semiconductors
Authors: Clauss W. , Kittel A. , Rau U. , Parisi J. , Peinke J. 
Published: February 2015

Abstract
We have investigated the dynamical behavior of p-Ge at the very onset of impact ionization breakdown. The statistical temporal distribution of the recurrent breakdown events exhibits a power law behavior supporting the model of selforganized criticality introduced by Bak, Tang, and Wiesenfeld.
Excited States Dipole Moments and Fluorescence Behaviour of Some Derivatives of Dimethylaminobenzonitrile
Authors: Brittinger C. , Maiti A. K. , Baumann W. , Detzer N. 
Published: February 2015

Abstract
Two sterically hindered derivatives of dimethylaminobenzonitrile (DMCA) have been synthesized and the dipole moment of their fluorescent excited state has been determined in differently polar solvents. Its value increases with solvent polarity up to a limiting value of (50 + 2.5) • 10-30 Cm. The results are discussed with reference to the twisted intramolecular charge transfer (TICT) state formation in the class of molecules related to DMCA.
A Reanalysis of 14N Nuclear Quadrupole Coupling and Methyl Internal Rotation in the Rotational Spectra of Monomethyl Oxazoles and Isoxazoles
Authors: Fliege Eckhard R. L. 
Published: February 2015

Abstract
Previously published rotational frequencies of 2-, 4-, and 5-methyl oxazole and of 3- and 5-methyl isoxazole are reanalysed to obtain correct rotational constants (A constants in the first place) on the basis of hypothetically unsplit rotational centre frequencies. With these, r0-structural parameters of the respective methyl group could be determined, thus allowing us to consider the influence of methyl substitution on the 14N-quadrupole coupling tensor and the structural relevance of the internal rotor angle given by torsional analysis.

14N nuclear quadrupole hfs and IAM methyl torsional analyses were redone with the correct rotational constants.