bluuebunny/crossref_metadata_2025_split huggingface dataset:
Information Contained in Open Systems by Example of Chemical Reaction Systems
Authors: Decker Ingo 
Published: February 2015

Abstract
Spatially homogeneous chemical reaction systems with one or two intermediate reaction pro-ducts and with autocatalytic reactionsteps are considered. Because of their non-linearities, such open systems show already primitive forms of self-organization. In order to express the "information" contained in the structures occuring, a theory is developped for measuring that quantity by help of a fictive detector: In treating the stochastic reaction kinetics in the Fokker-Planck-equation approximation, expressions are derived for the averaged amount of information one gets by doing a measurement with the detector and for the temporal conservation of the message being detected. This concept is applied to a one-component reaction scheme that exhibits a non-equilibrium phase transition of second order resulting in bistability of the steady state. When pushing this reaction system from the near equilibrium side through its critical region to bi-stability, a certain amount of information becomes quasi conserved, thus giving rise to a definition of the degree of order of a self-organizating system. The problem of how the reaction system can be integrated into a greater chemical network as a "bit"-generator, is discussed. To explain what is necessary for the onset of a hard mode instability giving birth to limit-cycle behaviour, a two-component reaction scheme is constructed by superposing onto reaction steps causing conservative concentration oscillations those reactions of the former model system which are responsible for the instability occuring there. By applying the information formalism, again, a quasi-conservation of information is indicated, but with respect to a much smaller time scale. The consequences for using oscillating reaction models as an information pump within a network, and the necessity of a feed-back mechanism in order to get real information storage, are shortly mentioned. Finally, a one-component reaction scheme is outlined that shows successive phase transitions, each of these instabilities bringing out a higher degree of organization.
25Mg2+ Nuclear Magnetic Relaxation in Aqueous Solution
Authors: Holz Manfred , Günther Siegfried , Lutz Otto , Nolle Alfons , Schrade Paul-Gerhard 
Published: February 2015

Abstract
Longitudinal nuclear magnetic relaxation rates of 25Mg2+ have been measured in aqueous solutions of MgCl2 and Mg(NO3)2 as a function of concentration. The value of 1/T1, extrapolated for infinite dilution has been compared with the "electrostatic theory" of Hertz. It turned out that the relaxation rate reflects the high cubic symmetry of the first hydration sphere of 25Mg2+ . Using the 1H and 25Mg2+ relaxation rates at finite salt concentration the "ion-ion contributions" to the 25Mg2+ relaxation rates have been determined. They are compared with those in aqueous LiCl solutions.
A big change in the 25Mg2+ relaxation rate in MgCl2 solution was found when a little amount of sodium citrate was added.
Electrochemical and Specific Heat Measurements on Tellurium-Halogen Systems
Authors: Haag J. , Alpen U. v. , Gmelin E. , Rabenau A. 
Published: February 2015

Abstract
Gibbs free energies of reaction in the systems Te-TeX4 (X = Cl, Br, I) were determined from e.m.f. measurements of solid state galvanic cells using silver halides as auxiliary electrolytes. From the temperature dependence of the e.m.f. the standard entropies and enthalpies of formation S0 (298.15 K) and ⊿Hf
0 (298.15 K) have been calculated for α-TeI, TeI4 , Te2 Br, TeBr4 , Te3Cl2 and TeCl4 . The specific heats of α-Tel and Te2Br were determined from 1.5 K to 300 K by adiabatic and differential scanning calorimetry.
Magnetische Eigenschaften der Normaltemperaturform von CsTmO2 / Magnetic Properties of the Normal-Temperature Form of CsTmO2
Authors: Urland Werner 
Published: February 2015

Abstract
The magnetic behaviour of the normal-temperature-form of CsTmO2 (NT-CsTmO2) has been studied in the temperature range between 2.9 and 251.3 K. In order to interpret the magnetic data a method applying the angular overlap model has been established to assess the crystal-field (CF) parameters of NT-CsTmO2 (CF symmetry: D3d) from the known CF parameters for Tm3+ substituted in YVO4 (CF symmetry: D2d)-With these CF parameters the observed magnetic properties of NT-CsTmO2 can be satisfactorily simulated. The calculation of the paramagnetic principal susceptibilities yields a high magnetic anisotropy, especially at low temperatures. The energy values of the CF levels of the 3H6 ground state are calculated.
The Profile of the Hel 4 3D, 3F – 2 3P (λ = 447.15 nm; λ = 447.0 nm) Spectral Line Emitted from a Low-Pressure Afterglow Plasma Submitted to a Magnetic Field of 10 Tesla
Authors: Drawin H. W. , Ramette J. 
Published: February 2015

Abstract
Measurement of the Hel line at λ = 447.15 nm during the recombination of a helium plasma in a magnetic field of induction B = 10 Tesla by means of a multichannel analyzer system with spectral and temporal resolution showed a Stark-Zeeman broadened line with a superposed line structure. - There are sufficient experimental indications to conclude that this structure is due to molecular transitions, in agreement with the observations for magnetic field-free afterglow plasmas. At the lowest electron densities also some of the weaker Zeeman components of both the allowed and forbidden transitions probably contribute to the structure. The existence of Baranger-Mozer plasma satellites under our experimental conditions could not be confirmed. - We observed further a relatively strong electron density-dependent asymmetry in the intensities of the two main lateral Zeeman-Stark components of the allowed line.
Anisotrope Fluoreszenz langgestreckter Moleküle in Lösungen / The Anisotropie Fluorescence of Prolate Molecules in Solutions
Authors: Kawski A. , Kukielski J. , Kamiński J. 
Published: February 2015

Abstract
Quantum chemical investigations of the electric dipole moments in the ground and excited states and also transition moments of 2,2′-p-phenylenebis (5-phenyloxazole) (POPOP) and 2,2′-p-phenylenebis (4-methvl-5-phenylaxazole) (2MPOPOP) were carried out with the PPP-CI-method. It was established that the transition moments of POPOP and 2MPOPOP are parallel to the long axis, whereas the electric dipole moments are mutually parallel and perpendicular to the long axis of these molecules. Further, the emission anisotropics r of the fluorescence of the prolate molecules POPOP. 2MPOPOP and the non-polar diphenvlenestilbene (DPS) in solvents of different viscosities η were investigated. Also for these substances the non-linear dependence of 1/r on T/η was confirmed. This deviation from the linear dependence is stipulated essentially through the length of the molecule. The effective volumes and the rotational relaxation times in different solvents of the studied molecules were determined.
On a Flexible Double Minimum Potential
Authors: Bohmann J. , Witschel W. 
Published: February 2015

Abstract
The Gauss-perturbed harmonic oscillator, a customary double minimum potential of molecular spectroscopy, is made more flexible by addition of a term α4 · exp(-γ4X4). The matrix elements of the additional term are calculated in the harmonic oscillator basis in terms of parabolic cylinder functions. A sum rule for matrix elements serves as an independent numerical control. The eigenvalues can be given by straightforward diagonalization of the Hamilton-matrix. In addition, upper and lower bounds are given for the partition function.
Homogeneous Photoredox System for Hydrogen Production by Solar Energy
Authors: Gohn M. , Getoff N. 
Published: February 2015

Abstract
In a redox system consisting of 5 × 10-5 mol dm-3 Ru(bpy)32+ complex, 4 × 10-3 mol dm-3 methylviologen and 5 × 10-3 mol dm-3 EDTA in aqueous solutions (pH = 3 to 8.5) without catalyst, hydrogen is formed under illumination with light λ > 360 nm. The highest yield was established in the pH-range between 4 and 5. The degradation of the components by prolonged use was studied spectroscopically. For comparison hydrogen evolution was also studied replacing EDTA by TEA or SCN-, respectively, in the above mentioned system.
Eine vergleichende Untersuchung des Einflusses von 25 Hauptgruppen- und Übergangselementchloriden als externe Spin-Bahn-Kopplungs- Störer auf das Lumineszenzverhalten von Coronen / A comparative Study on the Influence of 25 Main Group and Transition Element Chlorides as External Spin-Orbit Coupling Perturbers on the Luminescence Behaviour of Coronene
Authors: Zander M. 
Published: February 2015

Abstract
A characteristic change in the vibronic structure of the phosphorescence spectrum is the most sensitive external heavy-atom effect observed with coronene. A linear correlation exists between this vibronic effect and the increase of the phosphorescence/fluorescence quantum yield ratio. The observed decrease of the coronene phosphorescence/fluorescence quantum yield ratio in the presence of rare earth chlorides is probably due to an intermolecular energy transfer from the excited coronene molecule to the rare earth ion.
The Conductance of Tetraalkylammonium Iodides in Aqueous Proline and Hydroxyproline Solutions
Authors: Sesta B. , Mesa C. La , Cantale C. , Vincenzini M. 
Published: February 2015

Abstract
The density, viscosity and dielectric constant of aqueous proline and hydroxyproline solutions have been determined at 25 °C. The results appear to indicate that the two aminoacids have a destructive effect on the molecular water aggregates. The equivalent conductance of tetramethylammonium iodide and tetrabutylammonium iodide in aqueous proline and hydroxyproline solutions has been measured at 25°C. The aminoacids increase the viscosity of the solutions and decrease the limiting equivalent conductance of the two electrolytes. Electrostatic interactions of the iodide ions with the water molecules and hydrophobic interactions of the tetraalkylammonium ions with the aminoacids also seem to affect the conductometric behaviour of the electrolytes.
The Pair Correlation Function of the Liquid-Vapour Interface: A Monte Carlo Calculation
Authors: Borštnik B. , Ažman A. 
Published: February 2015

Abstract
A Monte Carlo simulation of the liquid-vapour interface near the triple point is reported. A monotonic density profile is obtained. In the entire interface the pair correlation function g(r) was found to be very close to the liquid bulk g(r), except for the low density region (ϱ(z)/(ϱliq ≦ 0.25 ) where information was inaccessible. The behaviour of the solution of the BGYB equation for the density profile is explored in the context of the new information concerning the pair correlation function in the interface.
Solvent Dependence of the Triplet Reactivity of Pivalophenone as Evidenced by Laser Flash Photolysis
Authors: Naito Ikuo , Schnabel Wolfram 
Published: February 2015

Abstract
Phenyl-t-butylketone (pivalophenone) was irradiated in mixtures of benzene and 2-propanol with 25 ns flashes of 347.1 nm light. Triplet lifetimes were measured by monitoring the decay of the T-T-absorption. 2-propanol exerts a significant stabilizing influence upon the triplet lifetime and lowers the triplet reactivity probably due to a n, π* → π, π* inversion of the lowest triplet state.
The Vibrational Spectra and Normal Coordinate Analysis of 3,3,3-Trifluoropropene and Hexafluoropropene
Authors: Christen D. , Hoffmann V. , Klaeboe P. 
Published: February 2015

The infrared spectra of 3,3,3-trifluoropropene and hexafluoropropene were studied in the vapour phase and in solution between 4000 and 40 cm-1 . Raman spectra of the compounds as vapours and liquids were recorded and polarization data obtained.
The spectra of both molecules are interpreted in terms of Cs symmetry. Complete vibrational assignments, including the torsional mode, are presented, based upon infrared and Raman vapour contours, Raman polarization measurements and the results of a normal coordinate analysis
Investigation of Mg-Bi Melts by Means of X-Ray- and Neutron Diffraction
Authors: Weber Michael , Steeb Siegfried , Lamparter Peter 
Published: February 2015

Abstract
Neutron diffraction experiments were done on Mg-Bi melts with eight compositions. From the measured intensities total structure factors and pair correlation functions as well as radial atomic distribution functions were calculated. The concentration dependence of the measured nearest neighbour distance and measured coordination number indicates the preference of unlike nearest neighbours within the Mg-Bi melts.
The neutron-intensity curves show premaxima at q ≅ 1.6 Å-1. X-Ray diffraction experiments performed on melts with three different compositions also yield corresponding premaxima. It could be shown that the premaximum intensity from the X-Ray as well as from the neutron experiment corresponds to the assumption that the premaxima are caused by modulation of the monotonic Laue scattering.
Structural Investigation of Bond-Isomeric Hexakis (Thiocyanato-isothiocyanato) osmates (III) from Os LIII-Edge EXAFS
Authors: Rabe P. , Tolkiehn G. , Werner A. , Haensel R. 
Published: February 2015

Abstract
The extended x-ray absorption fine-structure (ENAFS) has been used to determine bond lengths and coordination numbers around the central Os-atom in bond-isomeric hexakis (thiocyanato-isothiocyanato) osmates (III) [Os(NCS)n(SCN)6-n]3-, n = 1,...,6: The above assignment of the species with w-values is confirmed. The Os-N bond length decreases with increasing n while the Os-S bond length is the same in all compounds. The N-bonded ligands form an undistorted linear chain with the central Os-atom. The bond angles between the S-bonded ligands and Os-atoms are distorted by at least 10° around their average value (~ 105°).
Mass Spectrometric Investigations of the Evaporation of Crystalline Compounds of the System Cs2O-Al2O3-SiO2 Part II: The Compounds CsAlSiO4 and CsAlSi5O12
Authors: Odoj R. , Hilpert K. 
Published: February 2015

Abstract The evaporation of the synthetic compounds CsAlSiO4 and CsAlSi5O12 was studied by high temperature mass spectrometry. The measurements were carried out under equilibrium conditions with Knudsen cells in the temperature ranges 1242 to 1567 K (CsAlSiO4) and 1542 to 1803 K (CsAlSi5O12). The obtained Cs partial pressures are given by the equations
log p (Pa)=-18497/T(K)+11.85(CsAlSiO4)and
log p (Pa)=-26 974/T(K)+14.6(CsAlSi5012).
The probable uncertainty of the vapor pressures is ± 43%. The following enthalpies of sub­limation of Cs (g) were computed:
⊿Sub H°1405 (CsAlSiO4) =353.6 ± 9.8 kJ mol-1 and
⊿Sub H°1673 (CsAlSi5O12) =516.3 ± 18 kJ mol-1.
The Cs partial pressures over CsAlSiO4, CsAlSi5O12 and CsAlSi2O6 (see part I of this work [1]) are discussed with respect to their consequences for the final storage of high level radioactive waste.
UV-Absorptionsspektren methylsubstituierter Phenylcyclopropane / UV absorption Spectra of Me thy I substituted Phenylcyclopropanes
Authors: Bhaya Nuhudh D. , Shanshal Muthana 
Published: February 2015

Abstract
The UV absorption spectra of phenyl-cyclopropane(l), 267 nm, 1-methyl-1-phenyl-cyclopro-pane(2), 259 nm, o-tolyl-cyclopropane(3), 264 nm, m-tolyl-cyclopropane (4), 270 nm, and p-tolyl-cyclopropane(5), 280 nm are recorded in the gas phase, in methanol and in n-hexane. The hypsochromic shifts in the spectra of both 2 and 3 are explained in terms of a twisting of the phenylring out of the bisected conformation which causes an increase in the excitation energy. The spectra of 4 and 5, in which no steric factors are expected to twist the phenylring, show typical inductively caused bathochromic shifts. The vibronic structuring of all the absorption spectra are analyzed and found to include the frequencies 984, 964 and 1100 cm-1 that are attributed to the and the νas vibrations of the ν̃s cyclopropyl ring in the excited state. The results of the analysis confirm a recent assumption of a strong participation of the ⊿as Walsh MO of these Molecules in their electronic excitation processes.
Basalts in the Lancé Carbonaceous Chondrite
Authors: Kurat Gero , Kracher Alfred 
Published: February 2015

Abstract
We describe three lithic fragments from the Lancé carbonaceous chondrite which apparently are of igneous origin and of basaltic parentage. They consist of large enstatite grains (pheno-crysts ?) which poikilitically include some olivine and abundant Fe-Ni metal and Fe sulfide blebs. These enstatites are set into a matrix of partly ophitic and partly porphyritic plagioclase (~ an71) and interstitial clinopyroxene and clinopyroxene plus plagioclase intergrowths. Mineral compositions are highly variable and reflect a complex genesis. Olivine compositions range from fo5 to fo60 and sometimes exhibit compositional zoning. Enstatites are mostly of en 98 com-position with some Fe-enrichment towards grain surfaces and cracks. Plagioclases have about an71 but mostly are altered to nonstoichiometric high-alkali compositions (with original Al/Si ratios corresponding to ~ an 70) or are partly replaced by K-free nepheline. Generally two clinopyroxenes are present within the plagiophyric portions of the fragments: One low Fe/Mg augite (~ en53 wo44) rich in Ti, Al, Cr, and Mn (Fe/Mn ≦ 2) and a ferrosalite (~ en15 wo47) poor in Ti, Cr, and Mn (Fe/Mn ~ 100). One fragment also contains spinel (hercynite) which apparently is xenocrystic in nature.
Our investigation indicates: (1) The fragments are of igneous origin. (2) The original melt was of basaltic composition, crystallizing the primary mineral association ol + en + plag + low-Fe augite. (3) During crystallization the melt suffered strong reduction which led to segregation of Fe-Ni droplets from the melt and which continuously lowered the Fe/Mn ratio of successively crystallizing silicates from nearly chondritic (~ 100) to 0.6. (4) Probably after incorporation into the Lancé breccia the fragments suffered to different degrees metasomatic alterations which were caused by the addition of Na, K, and Fe to the system.
The origin of the pre-Lancé basaltic melt cannot yet be established.
The Bulk Composition of the Eucrite Parent Asteroid and its Bearing on Planetary Evolution
Authors: Dreibus Gerlind , Wänke Heinrich 
Published: February 2015

Abstract
It is shown that howardites fit extraordinary well into a binary mixing diagram for both their major and trace element compositions. Eucrites and diogenites would be suitable endmembers. In the mixing diagram computed from the elemental compositions of howardites, we find at a certain position a composition with very special features. This composition designated PR* contains all refractory incompatible elements in almost C 1, i.e. primitive, abundances. If 43% olivine is added to PR* in order to match the C 1 value for the Mg/Si ratio, a composition is obtained which has almost exact C 1 abundance values for all lithophile elements of non-volatile character. Because of its probable genetic relation we have used an olivine composition equal to that of pallasites. An eucrite parent body (EPB) with eucrites, diogenites and pallasites as the major building blocks has been previously suggested by various authors.
The bulk composition of the EPB, resulting from our computations is found to be almost chondritic, but with a considerable depletion of volatile and moderately volatile elements. A comparison of the bulk composition of the EPB with that of Earth and Moon reveals a number of remarkable differences. Thus, the similarity of the composition of the silicate phases of Earth and Moon becomes even more remarkable and must be taken as strong indication for the genetic relationship of Earth and Moon.
Mini-Excitons and Lattice Dynamics in Mixed CT-Crystals: An ESR, Optical and Raman Spectroscopical Study
Authors: Erdle E. , Möhwald H. 
Published: February 2015

Abstract
Mixed CT-crystals of composition anthracenecphenanthrene1-c-tetracyanobenzene (AnthcPhen1-c-TCNB, 0 ≦ c ≦ 1) have been investigated using ESR, optical and Raman spectroscopy. The data yield information on structural features and exciton transport as well as on the interrelation between these properties.
With respect to their structural properties the mixed crystals can be prepared into two classes: orientations and lacking molecular motion as well as a phase transitions. b) Crystals with excess anthracene (c < 0.5) are comparable to Anth-TCNB: they also undergo a first order phase transition though at a lower transitions temperature Tt (Tt = 155 K for c = 0.75, whereas Tt = 206 K for c = 1).
Mini-triplet-excitons confined to the anthracene moiety were found. Their diffusion takes place quasi-onedimensionally and independently of temperature, i.e. especially without being affected by the phase transition. This result holds for the fast component of the diffusion tensor as well as for the slow one.
109Ag NMR-Studies of the Selective Solvation of the Ag+ -Ion in Water-Ethylamine-Mixtures and of the Coordination of Halide-Anions to the Silver-Ethylamine Solvate Complexes
Authors: Kronenbitter J. , Schweizer U. , Schwenk A. 
Published: February 2015

Abstract

109Ag chemical shift measurements of 0.02 up to 3 molar solutions of AgNO3, AgCl, and AgBr in solvent mixtures of H2O (W) and ethylamine (ea) were performed. The extremely long relaxation times T1 and T2 were determined with new techniques.
The Ag+ -ion in solvent mixtures of W and ea shows a strongly selective solvation by ea. The 109Ag chemical shift of the solvate complex [Ag ea2]+ surrounded solely by W is δ2 = (335 ± 2) ppm (referred to the Ag+-ion in W). A further solvation in addition to the inner solvation sphere was determined; this solvation is not or only weakly selective. There is a rapid chemical exchange; the lifetime of the inner solvation sphere is long compared with the Larmor period, whereas the solvation outside this sphere is changed in times shorter than the Larmor period.
In contrast to the NO3- -anion, the halide anions Cl- and Br- are partly coordinated to the [Ag ea2]+ complex. The equilibrium constants for this coordination were determined as well as the chemical shifts of the [Ag ea2 · Cl] and the [Ag ea2 · Br] complexes. The bromine ion is coordinated for shorter times than the Larmor period, whereas the time of the coordination of the chlorine ion may be comparable to the Larmor period or shorter.
Kinetics of the Solid State Reaction between CuO and WO3
Authors: Lazzari M. , Bicelli L. Peraldo , Rivolta B. 
Published: February 2015

Abstract
The solid state reaction of CuWO4-x formation from CuO and WO3 was studied by the contact method in air and nitrogen. The results showed that the reaction is governed by the diffusion of the W6+ and O2- ions and that the rate determining step is the diffusion of oxygen ions in the reaction product. This is in agreement with the defect structure of copper tungstate, an n-type semiconductor with oxygen vacancies through which the diffusion process is possible.
(11̅1,11̅1̅/002) Enhanced Borrmann Effect in Heat Treated Czochralski Grown Silicon Crystals
Authors: Umeno M. , Hildebrandt G. 
Published: February 2015

Abstract
The “enhanced” Borrmann effect present in the ease of simultaneous reflection on (11̅1) and (11̅1̅) (three beam case (11̅1, 11̅1̅/002)) is for the first time applied to the investigation of defects in crystals, i.e. oxygen clusters in heat treated Czochralski grown Silicon. From a comparison of the three beam intensities with those of the two beam case on (220) with CuKα radiation in crystals annealed at 1000 °C it is concluded that at the beginning of the heat treatment a relaxation of the strains due to unstable positioning of the interstitial oxygen atoms and an increase of local strains due to the growth of precipitates proceeded simultaneously.