bluuebunny/crossref_metadata_2025 huggingface dataset:
Travelling Wave Solutions for Two Generalized Hirota-Satsuma Coupled KdV Systems
Authors: Fan Engui
Published: February 2015

In this paper we present an extended tanh method that utilizes symbolic computations to obtain more travelling wave solutions for two generalized Hirota-Satsuma coupled KdV systems in a unified way. The key idea of this method is to take full advantage of a Riccati equation involving a parameter and use its solutions to replace the tanh-function by the tanh method. It is quite interesting that the numbers and types of the traveling wave solutions can be judged from the sign of the parameter. In this paper we investigate the two generalized Hirota-Satsuma coupled KdV systems
Investigations of the EPR Parameters and Local Structures for Two Tetragonal Cr3+ Centers in NH4Cl Crystal
Authors: Wu Shao-Yi , Zheng Wen-Chen
Published: February 2015

In this paper, the zero-field splittings D and g factors g||, g⟂ at room temperature for two tetragonal Cr3+ centers in NH4Cl:Cr3+ crystal have been investigated by a two-spin-orbit (S.O)-parameter model, in which both the contribution due to the S.O. coupling of central d3 ion and that of ligands are considered. From the investigations, the signs of zero-field splitting and the local structures of both centers are ob­ tained. The electron paramagnetic resonance parameters D, g|| and g⟂ of both centers are also explained.
Mean Amplitudes of Vibration of Iodine Trifluoride
Authors: Baran E. J.
Published: February 2015

Mean amplitudes of vibration of IF3 have been calculated from vibrational spectroscopic data in the temperature range between 0 and 1000 K. Bond properties of the molecule are dis­ cussed on the basis of these results. Some comparison with relat­ed species are made.
Molecular Dynamics Simulation of Molten Alkali Nitrates
Authors: Vöhringer G. , Richter J.
Published: February 2015

Molecular dynamics (MD) simulations have been performed for several pure alkali nitrate melts. Special attention was paid to the examination of the interaction potential: macroscopic quantities like pressure were calculated and compared with real values. To improve the results the commonly used potential for alkali nitrates (Coulomb pair potential and Born-type repulsion) has been extended by a short-range-attraction term to meet the real behaviour of the liquid. With these improved potentials, simulations of pure LiNO3, NaNO3, KNO3, and RbNO3 have been performed with special regard to the influence of size and mass of the cations on the transport effects to show analogies to isotope effects. The calculated self diffusion coefficients (SDC) have been compared to results obtained with the NMR spin echo method.
Is Relativistic Quantum Mechanics Compatible with Special Relativity?
Authors: Lavenda B. H.
Published: February 2015

The transformation from a time-dependent random walk to quantum mechanics converts a modi­fied Bessel function into an ordinary one together with a phase factor e,ir/2 for each time the electron flips both direction and handedness. Causality requires the argument to be greater than the order of the Bessel function. Assuming equal probabilities for jumps ± 1 , the normalized modified Bessel function of an imaginary argument is the solution of the finite difference differential Schrödinger equation whereas the same function of a real argument satisfies the diffusion equation. In the nonrelativistic limit, the stability condition of the difference scheme contains the mass whereas in the ultrarelativistic limit only the velocity of light appears. Particle waves in the nonrelativistic limit become elastic waves in the ultrarelativistic limit with a phase shift in the frequency and wave number of 7r/2. The ordinary Bessel function satisfies a second order recurrence relation which is a finite difference differential wave equation, using non-nearest neighbors, whose solutions are the chirality components of a free-particle in the zero fermion mass limit. Reintroducing the mass by a phase transformation transforms the wave equation into the Klein-Gordon equation but does not admit a solution in terms of ordinary Bessel functions. However, a sign change of the mass term permits a solution in terms of a modified Bessel function whose recurrence formulas produce all the results of special relativity. The Lorentz transformation maximizes the integral of the modified Bessel function and determines the paths of steepest descent in the classical limit. If the definitions of frequency and wave number in terms of the phase were used in special relativity, the condition that the frame be inertial would equate the superluminal phase velocity with the particle velocity in violation of causality. In order to get surfaces of constant phase to move at the group velocity, an integrating factor is required which determines how the intensity decays in time. The phase correlation between neighboring sites in quantum mechanics is given by the phase factor for the electron to reverse its direction, whereas, in special relativity, it is given by the Doppler shift.
Analytic Solitary-wave Solutions for Modified Korteweg - de Vries Equation with t-dependent Coefficients
Authors: Hong Woo-Pyo , Yoona Myung-Sang
Published: February 2015

We find analytic solitary wave solutions for a modified KdV equation with t-dependent coefficients of the form ut - 6α(t)uux + ß (t) uxxx -6γu2ux = 0. We make use of both the application of the truncated Painleve expansion and symbolic computation to obtain an auto-Bäcklund transformation. We show that kink-type analytic solitary-wave solutions exist under some constraints on α (t), ß (t) and γ.
Ionic Interactions in Actinide Tetrahalides
Authors: Akdeniz Z. , Karaman A. , Tosi M. P.
Published: February 2015

We determine a model of the ionic interactions in AX 4 compounds (where A is an atom in the actinide series from Th to Am and X = F, Cl, Br or I) by an analysis of data on the static and dynamic structure of their molecular monomers. The potential energy function that we adopt is taken from earlier work on rare-earth trihalides [Z. Akdeniz, Z. Q q e k and M. P. Tosi, Z. Naturforsch. 55a, 861 (2000)] and in particular allows for the electronic polarizability of the actinide ion. This polarizability quantitatively determines the antisymmetric-bending vibrational mode, but its magnitude remains compatible with a symmetric tetrahedral shape of the molecule at equilibrium. The fluorides have an especially high degree of ionic character, and the interionic-force parameters for each halide of the U, Np, Pu and Am series show regular trends, suggesting that extrapolations to the other transuranic-element halides may usefully be made. The Th compounds show some deviations from these trends, and the interionic-force model that we determine for ThCl4 differs somewhat from that obtained in a previous study. We therefore return on the evaluation of the relative stability of charged oligomers of ThCl4 and ZrCl4 and find confirmation of our earlier results on this problem.
Structural Study of Liquid Lithium Niobate by Neutron Diffraction Role of the Li Atom in the Clustering Near Solidification
Authors: Andonov P. , Fischer H. E. , Palleau P. , Kimura S.
Published: February 2015

The structure of liquid LiNbO3 has been investigated by neutron diffraction using samples with different isotopic composition of lithium. The intensity scattered by these samples has been measured for momentum transfers 0.4 Å-1 T> 1500 K, which include the undercooling domain. From an analysis of the correlation functions Gij(r) of the atomic pairs Li-Li, Li-Nb, Li-O and their structural evolutions, given by Δ Gi-j (r) = Gi-j(r)1500 -Gi-j(r)1550 made with reference to the crystalline LiNbO3 ferroelectric structure, it was possible to confirm a local ordering similar to that of the crystal. The presence of clusters (groupings of NbO3 octahedra) is confirmed. Both regular and irregular N b06 octahedra are observed in the liquid near solidification. With its high mobil­ity in the melt, the Li atom plays an important role in the clustering: the Li-O and Li-Nb bonds make possible the staking of four octahedra groups into clusters of eight octahedra or more. The Li-Li bonds join these groups. The diameter of the clusters is a least 22 Å in the undercooling regime.
Ground and Excited State Dipole Moments of BADAN and ACRYLODAN Determined from Solvatochromic Shifts of Absorption and Fluorescence Spectra
Authors: Kawski A. , Kukliriski B. , Bojarski P.
Published: February 2015

The electric dipole moments in the ground μg, and excited states μe of the fluorescent probes BADAN (6-bromoacetyl-2-dimethylamino-naphthalene) and ACRYLODAN (6-acrylolyl-2-dimethylamino-naphthalene) are determined from the solvatochromic shifts of their absorption and fluorescence spec­tra for two Onsager interaction radii (a = 4.2 and 4.6 Å). The obtained values of μg and μe for BADAN are comparable to those of PRODAN, while for ACRYLODAN they are distinctly greater.
The Rotational Spectrum of (17O)Ketene
Authors: Guarnieri A. , Huckauf A.
Published: February 2015

The rotational spectrum of H2CC17O in the ground vibrational state has been investigated between 20 and 330 GHz. From 82 R-branch transitions a set of rotational constants and several centrifugal distortion constants could be derived, employing the Watson 5-reduction formalism. The obtained rotational constants in MHz are: A = 282071.6(223), B = 10013.4764(28), C = 9655.9118(24). The nuclear quadrupole coupling structure of the J'Ka'Kc' <- JKaKc = 101 O00 line has been recorded by means of molecular beam Fourier transform microwave spectroscopy allowing the determination of the nuclear quadrupole constant Xaa. = -1.534(54) MHz (without considering the spin-rotation interaction). A recalculation of the rs-structure has also been carried out, using the constants of the new isotopomer. The result agrees with the values reported by East et al. in 1995. This is, to our knowledge, the first reported investigation of the H2CC17O rotational spectrum.
Molecular Dynamics Study on the Adsorption Selectivity for Negative Elements in Aluminosilicates
Authors: Matsumiya Masahiko , Takagi Ryuzo
Published: February 2015

For the pyrochemical reprocessing of spent metallic nuclear fuels in molten salt baths it is important to investigate the adsorption selectivity of cations in aluminosilicates. A molecular dynamics simulation has been performed on sodalite and zeolite with exchangeable monovalent and multivalent cationic fission products at 673 K in order to calculate their self-diffusion coefficients in the aluminosilicate framework and estimate the selectivity of the exchangeable cations. The results enables us to conclude that the self-diffusion coefficients of monovalent cations decrease with increasing ionic radius. The order of the adsorption selectivity is Li < Na < K < Cs in zeolite. The self-diffusion coefficients of multivalent cations are

almost independent of the ionic radius, and these cations are in aluminosilicates more stable than

monovalent cations. The results are consistent with the experimental results.
DTA and Dielectric Studies under Pressure of a Smectogen Substance with a Strong Perpendicular Dipole Moment
Authors: Urban Stanislaw , Wiirflinger Albert
Published: February 2015

The phase diagram of a substance with two CN groups attached to the benzene ring at lateral posi­ tions (CNCN) has been obtained with differential thermal analysis (DTA). The pressure range of the smectic A phase is limited, resulting in a triple point (Cr, SA, L) at 135 MPa and 371 K. However, the SA-phase exists also above the triple point as a metastable phase. The transverse relaxation times τ⟂ were obtained from the dielectric spectra measured for several isotherms as a function of pressure with­ in the SA-phase of CNCN. The activation volume, Δ#V⟂ = RT (∂ In τ⟂/∂p)T, = (52 ± 3) cm3/mol is larg­er than Δ#V|| , recently derived from the pressure dependence of the longitudinal relaxation times for other substances in the SA-phase. It is concluded that due to steric hindrances made by the cyano groups the molecular rotations around the long axes become strongly slowed down by pressure and the smec­ tic phase disappears
Vibration Frequencies and Normal Coordinates of 3Radialene
Authors: Kubba Rehab M.
Published: February 2015

SCF-MO calculations of the vibration frequencies and IR absorption intensities of 3radialene are re­ ported. Complete normal coordinate analysis for the molecule was done. The C=C str. frequencies of 3radialene are found to be intermediate between the values for ethylene and acetylene. The results are explained in terms of a modified Förster-Walsh model for the 3ring in which the central carbon atoms show sp hybridization.
Effect of Low-Frequency Modulation on Thermal Convection Instability
Authors: Bhatia P. K. , Bhadauria B. S.
Published: February 2015

The stability of a horizontal layer of fluid heated from below is examined when, in addition to a steady temperature difference between the horizontal walls of the layer a time-dependent low-frequency per­ turbation is applied to the wall temperatures. An asymptotic solution is obtained which describes the be­ haviour of infinitesimal disturbances to this configuration. Possible stability criteria are analyzed and the results are compared with the known experimental as well as numerical results.
Low-frequency Raman Spectroscopy of Aqueous Solutions of Aliphatic Alcohols
Authors: Ydoshida Koji , Yamaguchi Toshio
Published: February 2015

Low-frequency Raman spectra have been measured at room temperature as functions of the alcohol mole fraction in aqueous solutions of methanol, ethanol, 1-propanol, 2 -propanol, and /er/-butylalcohol (TBA). Intrinsic Raman spectra R (ῡ) were obtained from depolarized Rayleigh wing spectra. Isosbestic points have been observed in R (ῡ) of the aqueous solutions of ethanol, 1-propanol, and 2 -propanol, suggesting that the structure o f the solutions is characterized by individual alcohol aggregates and water clusters without a significant amount of alcohol-water mixed aggregates. The R (ῡ) spectra have been expressed as R (ῡ ,x ) = w R (ῡ ,0 ) + aR(D, 1), where R(ῡ, 0) and R(ῡ, 1) are those for pure water and pure alcohols, respectively, and x is the mole fraction of alcohols. The coefficients w and a show the inflection points at characteristic alcohol mole fractions, where microhetrogeneity and structural transition of the solvent clusters take place, as previously shown by X-ray diffraction. In the aqueous solutions of methanol, where no microhetrogeneity takes place, no clear isosbestic point in R(ῡ) has been observed. For aqueous solutions of TBA, an isosbestic point in R(ῡ) has appeared when xTBA > 0.05. Two inflections points in the coefficients have been observed at xTBA « 0.1 and 0.35; the former composition corresponds to the transition composition from the TBA-TBA intermolecular contact to the TBA water molecular association, as previously reported by neutron diffraction.
Nuclear Spin Relaxation and Water Self-diffusion in Hardening Magnesium Oxychloride Cement
Authors: Nestle Nikolaus , Galvosas Petrik , Zimmermann Christian , Dakkouri Marwan , Kärger Jörg
Published: February 2015

In this contribution, we report the results of NMR studies of the behaviour of water in a hydrating Sorel cement paste with a composition close to the stoichiometric optimum. Both the transverse spin-relaxation behaviour and water self-diffusion were studied in two separate experiments performed on samples on the basis of the same formulation. While there is a very strong initial decrease in the transverse relaxation time of the water in the paste, the diffusion coefficient is found to decrease mainly at later times of the hydration process where the decrease of the transverse relaxation time has already strongly slowed down. After about 6 h of the hardening process, the signal intensity available for a pulsed gradient diffusometry experiment is not sufficient any more for reliable measurements of the diffusion coefficients
Energy Eigenvalue Level Motion with Two Parameters
Authors: Steeb Willi-Hans , Hardy Yorick , Stoop Ruedi
Published: February 2015

From the eigenvalue equation Ĥλ|(ψn)〉 = En(λ)|ψn(λ)〉 where Ĥ0 = Ĥ0 + XV̂ one can derive an autonomous system of first order ordinary differential equations for the eigenvalues En(λ) and the matrix elements Vmn(λ) := 〈ψm|V̂|ψn(λ)〉 where λ is the independent variable. We derive the partial differential equations for the extended case Ĥλ1λ2= Ĥ0 + λ1V̂1 + X2V̂2, where λ1 and λ2 are the independent variables. Some applications of this system of partial differential equations are discussed.
Dielectric Permittivity and AC Conductivity Investigation for the New Model Lipid Bilayer Material: (CH2)10(NH3)2CdCl4
Authors: Mostafa Mohga F. , Youssef Ahmed A. A.
Published: February 2015

Differential thermal scanning of the new lipid-like bilayer material (CH2)10(NH3)2CdCl4 showed two structural phase transitions, with onset temperatures at T2 = (359 ± 2) K and T1 = (415± 1) K. Permittiv­ity measurements were performed between room temperature and 450 K at 60-100 kHz. A step-like rise in permittivity at T2, associated with an order-disorder transition, is attributed to chain melting. Two anomalies at (413 ± 1) K and (430 ± 3) K, showing thermal hysteresis of -8 and 10 K, respectively, in­ dicate first order transitions which are associated with crystalline phase change. The AC conductivity follows an Arrhenius-type relation with the activation energy ΔE varying with the frequency / according to the relation ΔE = ΔE0 [1 -exp (f0/f)] where ΔE0,f0 and a are 0.95 eV, 52 Hz and 0.11, respectively. The frequency dependent conductivity follows the power law σ= σdc +Bωx with 0.3 <s< 1.5 for hopping conduction of hydrogen and/or chloride ions in the high temperature range, and localized hopping and/or orientational motion predominating temperatures lower than 413 K. Variations of B and s with temperature are discussed. PACS No. 76, 77
Dielectric Relaxation of Three Ethanolamines
Authors: Wichmann M. , Stockhausen M.
Published: February 2015

Relaxation spectra have been measured at 20°C for mono-, di-and triethanolamine in the pure liquid state and in a 0.6 mole fraction mixture with 1,4-dioxane. The general resemblance to the dielectric behaviour of alcohols and aminoalcohols shows that relaxation is governed by association effects. In this regard, several features point to significantly differing behaviour of the mono compound in comparison with both di-and triethanol­ amine.
Thermodynamics and Structure of Liquid Metals from a New Consistent Optimized Random Phase Approximation
Authors: Badirkhan Z. , Pastoreb G. , Akinlade O.
Published: February 2015

We study thermodynamics and structural properties of several liquid metals to assess the validity of the generalized non-local model potential (GNMP) of Li et al. [J. Phys. F16, 309 (1986)].

By using a new thermodynamically consistent version of the optimized random phase approx­ imation (ORPA), especially adapted to continuous reference potentials, we improve our previous results obtained within the variational approach based on the Gibbs -Bogoliubov inequality.

Hinging on the unified and very accurate evaluation of structure factors and thermodynamic quantities provided by the ORPA, we find that the GNMP yields satisfactory results for the alkali metals. Those for the polyvalent metals, however, point to a substantial inadequacy of the GNMP for high valence systems.
A New Generalization of the (2+1)-dimensional Davey-Stewartson Equation
Authors: Lin Ji , Tang Xiao-yan , Lou Sen-yue , Wang Ke-lin
Published: February 2015

Using an asymptotically exact reduction method based on Fourier expansion and spatiotemporal re-scaling, a new integrable system of the nonlinear partial differential equation in (2+1)-dimensions, extended Davey-Stewartson I equation, is deduced from a known (2+1)-dimensional integrable equation. The integrability of the new equation system is explicitly proved by the spectral transformation. Actually, the corresponding Lax pair of the new equations can be obtained by applying the same reduction method to the Lax pair of the original equation.
Abundant Coherent Structures of the (2+1)-dimensional Broer-Kaup-Kupershmidt Equation
Authors: Ying Jin-ping , Lou Sen-yue
Published: February 2015

By using of the Bäcklund transformation, which is related to the standard truncated Painleve analysis, some types of significant exact soliton solutions of the (2+1)-dimensional Broer-Kaup-Kupershmidt equation are obtained. A special type of soliton solutions may be described by means of the variable coefficient heat conduction equation. Due to the entrance of infinitely many arbitrary functions in the general expressions of the soliton solution the solitons of the (2+1)- dimensional Broer-Kaup equation possess very abundant structures. By fixing the arbitrary functions appropriately, we may obtain some types of multiple straight line solitons, multiple curved line solitons, dromions, ring solitons and etc.
pVT Measurements and Related Studies on the Binary System nC16H34 -nC17H36 and on nC18H38 at High Pressures
Authors: Würflinger Albert , Mondieig Denise , Rajabalee Fazil , Cuevas-Diarte Miquel Angel
Published: February 2015

The phase diagram of the binary system nC16H34 -nC17H36 has been established at ambient pressure using DSC and crystallographic measurements. At low temperatures below the rotator phase RI there exist two crystal forms Op (about x(C17) = 0.25) and Mdci (about x(C17) = 0.67) which are different from the crystal structures of the pure compounds (Tp for C16 and Oi for C17). Furthermore two compositions: (a) C16/C17 = 3:1 and (b) = 1:2, which correspond to the coexistence range of Op and Mdci, were chosen for high pressure DTA and pVT measurements, yielding the following findings: The specific volume of the rotator phase of C17 is distinctly lower than those of the binary systems at the same state point. Assuming the existence of a metastable rotator phase for C16, an excess volume of Δ VE/V ≈ 0.01 can be estimated. Due to the very enlarged coexistence range of RI, the mixtures reach their lower transition point at considerably lower temperatures (in isobaric measurements) or higher pressures (in isothermal measurements), where the specific volume is lower than that of C17 at its transition point. Furthermore, the volume and enthalpy changes of the Φord -RI transition is distinctly smaller for the binary systems than for pure C17. Thus the specific volumes of the phases Op and Mdci are appreciably larger than ν(spec.) of C17. Op and Mdci have practically the same specific volume in accordance with the crystallographic results. Enthalpy values are obtained with the aid of the Clausius-Clapeyron equation which agree well with enthalpies derived from the DSC measurements.

Furthermore, pVT data have been established for the liquid and solid phases of nC18H38 in the neighbourhood of the melting curve, allowing to determine volume and enthalpy changes of melting as a function of pressure.
Isolated versus Condensed Anion Structure VII: X-ray Structure Analysis of 1,3-Propanediammonium Dibromodichlorocadmate(II), [H3N(CH2)3NH3]CdBr2Cl2, and Estimation of Stability of Five-coordinated Halide Anions, MX5
3-(M = Cd, Zn; X = Cl, Br) by Means of Ab-initio MO Calculations
Authors: Ishihara Hideta , Okajima Toshiya , Horiuchi Keizo , Svoboda Ingrid , Fuess Hartmut
Published: February 2015

The coordination capability of Cl and Br in halogenocadmate(II) complexes is estimated by a solution of the structure of 1,3-propanediammonium dibromodichlorocadmate(II). The compound crystallizes as a layered anion structure with Cl bridges and Br terminals at 293 K: Imma, a = 741.56(7), b = 1869.5(5), and c -771.55(8) pm, Z = 4. In order to explain the stronger tendency of halogenocadmate(II) complexes to form layered structures as compared to halogenozincate(II), ab-initio calculations were performed. The stability of MX5
3-(M = Cd, Zn; X = Cl, Br) is compared. Isolated ZnX5
3- and CdBr5
3- ions are not stable. On the other hand a trigonal bipyramid CdCl5
3- ion is considered to be subtly stable in the crystal mainly due to Coulomb attractive interactions between the positively charged metal cation Cd2+ in a CdCl3- fragment and two Cl- ions.
Thermodynamic Properties of EuCl2 and the NaCl-EuCl2 System
Authors: Da Silva F. , Rycerz L. , Gaune-Escard M.
Published: February 2015

The temperature and enthalpy of the phase transition and fusion of EuCl2 were determined and found to be 1014 K, 11.5 kJ mol-1and 1125 K, 18.7 kJ mol-1 , respectively. Addition­ ally, the heat capacity of solid EuCl2 was measured by Differential Scanning Calorimetry in the temperature range 306 -1085 K. The results were fitted to the linear equation C0
p,m = (68.27 + 0.0255 T/K) J mol -1 K-1 in the temperature range 306 -900 K. Due to discrepancies in the liter­ ature on the temperature of fusion of EuCl2, the determination of the NaCl-EuCl2 phase diagram was repeated. It consists of a simple eutectic equilibrium at Teut = 847 K with x(EuCl2) = 0.49.
Calorimetric Investigation of MCI-EuCI2 Melts (M = Na, K, Rb)
Authors: Da Silva F. , Rycerz L. , Gaune-Escard M.
Published: February 2015

The molar enthalpies of mixing (ΔmixHm) of MCl-EuCl2 (M = Na, K, Rb) liquid binary systems were measured at 1138 K over the whole composition range by direct calorimetry. A Calvet type calorimeter was used, and mixing of the two liquid components was achieved by the ampoule break-off technique under argon at atmospheric pressure. The enthalpy of mixing of these systems is negative over the whole composition range with a minimum of approximately -0.5, -3.5 and -4.5 kJ mol-1 for M = Na, K, Rb, respectively. The least-squares coefficients A, B, C in the equation A (kJ mol-1) = A + B x + C x2, where λ is an interaction parameter, are reported. From the trend observed in these MCl-EuCl2 systems it was possible to estimate the mixing enthalpy of the CsCl-EuCl2 system.
Control and Adaptation of Spatio-temporal Patterns
Authors: Diebner Hans H. , Hoff Axel A. , Mathias Adolf , Prehn Horst , Rohrbach Marco , Sahle Sven
Published: February 2015

We apply a recently introduced cognitive system for dynamics recognition to a two-dimensional array of coupled oscillators. The cognitive system allows for both the control and the adaptation of spatio-temporal patterns of that array of oscillators. One array that shows Turing-pattems in a self-organizational manner is viewed as an externally presented dynamics (stimulus) which is mapped onto a mirror dynamics, whereby the latter is capable to simulate (simulus). Two of the parameters of the stimulus are thereby regarded to be unknown and have to be estimated by the cognitive system. The cognitive system itself consists of dynamical modules that are stimulated by the external dynamics in the sense of Pyragas' external force control mechanism and thereby yield measures of how good they match the stimulus. These measures are used as weights to construct the simulus. The adaptation process is performed "on the fly", i. e., without the storage of data. The proposed cognitive system, therefore, is a prominent candidate for the construction of a control device for a permanent real time observation of an external dynamical system in order to interfere instantaneously when necessary.
Conductivities of Room Temperature Molten Salts Containing AlCl3, Measured by a Computerized Direct Current Method
Authors: Hsu Hsin-Yi , Yang Chao-Cheng
Published: February 2015

The conductivities of the binary room-temperature molten salt systems AlCl3-N-n-butylpyridinium chloride (BPC), AlCl3-l-ethyl-3-methylimidazolium chloride (EMIC) and AlCl3-benzyltriethylammo-nium chloride (BTEAC) have been measured at different temperatures and compositions by a d.c. four-probes method.

There is a maximum of the conductivity at 50 mol% AlCl3 in the AlCl3-BPC and AlCl3-EMIC systems at 40 to 80 °C, their activation energies being relatively low (20.79 and 14.76 kJ/mol, respec­ tively). As to the A1C13-BTEAC system, there is an irregular change in the conductivity at 40-70 mol% AlCl3 in the temperature range 50 to 80 °C. The conductivities of the three RTMS are in the order AlCl3-EMIC > AlCl3-BPC > AlCl3-BTEAC, the reason being discussed.
Effect of Li Content on the DSC and Electrical Conductivity of (Li1-xKx)2SO 4 Mixed Crystals
Authors: Ahmad M. M. , Hefnia M. A.
Published: February 2015

Differential scanning calorimetry on (Li1-x Kx)2SO4 mixed crystals, where x = 0.01, 0.1, 0.3 and 0.5, revealed that, as the potassium content increases, the first high temperature phase of the intermediate LiKSO4 phase at T - 432 °C grows and shifts to higher temperature, and a double-phase mixture consisting of LiKSO4 and Li2SO4 exists for x< 0.5. Ionic conductivity measurements on (Li1-xKx)2SO4 mixed crystals for x < 0.5 did show that the electrical conductivity increases as the Li2SO4 concentration increases, with an average activation energy of 0.9 eV. The enhanced electrical conductivity is primarily a result of the increase in the Li+ ion (charge carriers) concentration and/or the formation of a diffuse space charge layer at the interface between the two phases.
The Value of Sommerfeld's Finestructure Constant as a Consequence of the Planck-Aether Hypothesis
Authors: Winterberg F.
Published: February 2015

A value of the finestructure constant at the unification eneigy is obtained by a dimensional analysis of quantum gravity and fluid dynamics. The derivation assumes that the vacuum is a superfluid made up of positive and negative Planck mass particles obeying an exactly nonrelativistic law of motion with Lorentz invariance a low energy approximation. The dimensional analysis presented gives a value for the finestructure constant in good agreement with the empirical value 1/α = 25.
Induced Smectic-G Phase through Intermolecular Hydrogen Bonding Part VIII: Phase and Crystallization Behaviours of 2-(p-n-heptyloxybenzyIidene imino)-5-chIoro-pyridine: p-n-alkoxybenzoic acid (HICP:n ABA) Complexes
Authors: Srinivasulu M. , Satyanarayana P. V. V. , Kumar P. A. , Pisipatia V. G. K. M.
Published: February 2015

New intermolecular H-bonded liquid crystalline complexes, viz., 2-(p-n-heptyloxybenzylidene imi-no)-5-chloro-pyridine:p-/z-alkoxybenzoic acid; (HICP:nABA) (where n denotes the alkoxy carbon num­ bers 3 to 10 and 12) exhibiting smectic-F (n = 12) and smectic-G phases have been synthesized and char­ acterized by Thermal Microscopy and Differential Scanning Calorimetry (DSC). Detailed IR (solid and solution states) analysis confirms the existence of intermolecular H-bonding between the pyridyl nitro­ gen and the COOH group of the p-n-alkoxybenzoic acid moiety. The phase behaviour of the series is discussed in the light of reported data on free p-n-alkoxybenzoic acids. The crystallization kinetics of a representative complex, using the DSC technique, is discussed. The mechanism of the crystal growth of the new crystalline smectic-G phase is computed with the Avrami equation.
Density Measurement of Molten KHF2
Authors: Matal Oldřich , Žaloudek Josef , Cigánek Frantisek , Slavíček Pavel , Žmij Bronislav , Nejedlý Milan
Published: February 2015

An apparatus has been manufactured to measure the density of molten KHF2. A linear dependence of the density on temperature is found in the range of 280-450 °C.
Quantum Effect on Collisions in Electron-positron Plasmas
Authors: Jung Young-Dae
Published: February 2015

Quantum effects on the electron-positron scattering are investigated in electron-positron plasmas. The corrected Kelbg potential, taking into account the quantum effects, is applied to describe the electron-positron interaction potential in electron-positron plasmas. The Bom approximation is considered to obtain high-energy electron-positron scattering cross sections. The results show that the differential electron-positron scattering cross sections increase with increasing thermal de Broglie wavelength, i.e., decreasing plasma temperature. The differential electron-positron scattering cross sections decreases with increasing collision energy. It is also found that the quantum effects on the differential scattering cross section are small for forward and backward scattering angles.
Structure and Binding of Ionic Clusters in Th and Zr Chloride Melts
Authors: Akdeniz Z. , Tosi M. P.
Published: February 2015

We discuss microscopic ionic models for the structure and the binding of small clusters which may exist as structural units in molten ThCl4 and ZrCl4 and in their mixtures with alkali halides according to Raman scattering studies of Photiadis and Papatheodorou. The models are adjusted to the two isolated tetrahedral molecules. Appreciably higher ionicity is found for ThCl4 than for ZrCl4, and this fact underlies the strikingly different behaviour of the two systems in the dense liquid state -in particular, a molecular-type structure for molten ZrCl4 against a structure including charged oligomers in molten ThCl4.
Structure of Rare-earth/Alkali Halide Complexes
Authors: Akdeniz Z. , Önem Z. Çiçek , Tosia M. P.
Published: February 2015

Vapour complex formation of rare-earth halides with alkali halides strongly increases the volatility of these compounds. We evaluate the structure taken by such complexes having the chemical formulas MRX4, M2RX5 and M3RX6, where X = F or Cl and typically M = Li or Na and R = La. The roles played by the two types of metal atom is investigated in MRX4 complexes by also taking M = K, Rb or Cs and R = Gd or Lu. The main predictions that emerge from our calculations are as follows: (i) in MRX4 a fourfold coordination of the rare-earth atom is accompanied by twofold or threefold coordination of the alkali atom, the energy difference in favour of the twofold-coordination state being about 0.3 eV in the case of the LiF complexing agent but even changing sign as the ionic radius of either the alkali or the halogen is increased; (ii) in M2RX5 a fivefold coordination of the rare-earth atom is energetically more stable than a fourfold one, by again not more than about 0.3 eV; (iii) in M3RX6 the fivefold and sixfold coordinations of the rare-earth atom are energetically competitive; and (iv) in both M2RX5 and M3RX6 each coordination state can be realized in various forms that differ in detail but are close in energy. Bond fluctuations and disorder around the rare-earth atom can be expected to be a general feature at elevated temperatures, both in the vapour and in liquid rare-earth/alkali halide mixtures.
Current Efficiency Obtained with SnO2-based Inert Anodes in Laboratory Aluminium Cell
Authors: Popescu Ana-Maria
Published: February 2015

A systematic study of the current efficiency (CE) in a laboratory aluminium cell with SnO2-based inert anodes was carried out by measuring the overall amount of oxygen relieved at the anode, using two different methods.

Inert ceramic anodes of 96% SnO2, 2% Sb2O3, 2% CuO in wt% composition were prepared and investigated. The influence of: temperature, current density, anode-cathode distance, cryolitic ratio, content of alumina and different additives was studied. At the same time the influence of the age of boron nitride (BN) sheath of the inert anode on the CE was evaluated.
Electrochemical and Thermodynamic Properties of EuCl3 and EuCl2 in an Equimolar NaCl-KCl Melt
Authors: Kuznetsov S. A. , Rycerz L. , Gaune-Escard M.
Published: February 2015

The electroreduction of EuCl3 in an equimolar NaCl-KCl mixture was studied at 973 -1123 K by different electrochemical methods. This reduction of Eu(III) in NaCl-KCl melt occurs via two successive reversible steps involving transfer of one and two electrons. The diffusion coefficients of Eu(III) and Eu(II) were measured by linear sweep voltammetry and chronopotentiometry. The values found by these methods are in a good agreement. The standard rate constants for the redox reaction Eu(III) + e~ Eu(II) were calculated from cyclic voltammetry data. The sluggish kinetics of this reaction is discussed in terms of substantial rearrangement of the europium coordination sphere. Special attention was paid to the choice of working electrodes for the study of electrode reactions. The formal standard potentials E*E u (^ /Ba, E* eU (hr/eu and the formal redox potentials ^*Eu(ni)/Eu(ii) were determined from open-circuit potentiometry and linear sweep voltammetry data. The free Gibbs energy changes for the reaction EuCl3(so1) EuCl2(SOi.) + 1/2 Cl2(g.) and the equilibrium constants of the metal-salt reaction 2Eu(III) + Eu 3 Eu(II) were calculated. The thermodynamics of the formation of dilute solutions of europium di-and trichloride in an equimolar NaCl-KCl melt were determined. It was shown that electrochemical transient techniques give the possibility of the determination of the relative partial molar mixing enthalpy of europium trichloride and dichloride in NaCl-KCl melt.
The Electrical Conductivity of Molten (Ag, Cd1/2)Br
Authors: Wojakowska Alina , Gòrniak Agata
Published: February 2015

The electrical conductivity of molten (Ag, Cd1/2)Br has been determined as a function of temperature in the whole range of compositions. The resulting activation energy values and the conductivity isotherm at 850 K are compared with those of the system (Ag, Cd1/2)Cl.
The Polysurface Mechanism of Ta and Ti Anodic Dissolution in Low-Temperature Carbamide-NH4CL Melt
Authors: Volkov S. , Tumanova N. , Kothetova S. , Buryak N.
Published: February 2015

In this work the peculiarities of the electrochemical dissolution of tantalum and titanium in carbamide containing low temperature melts were studied.
Structural Investigation of Vanadium-Sodium Metaphosphate Glasses
Authors: Chrissanthopoulos A. , Pouchan C. , Papatheodorou G. N.
Published: February 2015

Paper presented a t the NATO A dvanced Study Institute, May 4-1 4 , 2001 (Kas, Turkey) The structure of the glass forming system (V2O5)x -(Na2O • P2O5)(1-x), (x = 0-0.4), has been inves­ tigated using Raman spectroscopy. The stretching vibrations of various phosphate groups, connected to phosphorus or vanadium atoms, have been assigned. Variation of the composition leads to structural changes where the sodium metaphosphate -P-O-P-chains break and then reconnect with the oxovana-dium units forming a -V-O-P-network structure.
A Dielectric Relaxation Study of Diethylsulfoxide/ Tetrachloromethane Binary Mixtures
Authors: Markarian S. A. , Galstian A. S. , Stockhausen M.
Published: February 2015

The dielectric spectra of diethylsulfoxide (DESO)/tetrachloromethane mixtures have been measured from 0.5 to 72 GHz at 20 °C. On the basis of the relation between the relaxation time and the DESO concentration a complex formation between DESO and tetrachloromethane is suggested.
Abundant New Exact Solutions of the Coupled Potential KdV Equation and the Modified KdV-Type Equation
Authors: Yan Zhenya
Published: February 2015

Exact solutions of nonlinear evolution equations (NLEEs)in soliton theory and their applications are studied. A powerful method is established to search for exact travelling wave solutions of NLEEs. We chose the coupled potential KdV equation and modified KdV-type equations presented by Foursov to illustrate the approach with the aid of Maple. As a result, eight families of exact solutions of the coupled potential KdV equation and nine families of exact solutions of the modified KdV-type equations are obtained, which contain new kink-like soliton solutions, kink­ shaped solitons, bell-shaped solitons, periodic solutions, rational solutions and singular solitons. The properties of the solutions are shown in figures.
Abundant New Multiple Soliton-like Solutions and Rational Solutions of the (2+1)-Dimensional Broer-Kaup Equation
Authors: Yan Zhenya
Published: February 2015

In this paper we firstly improve the homogeneous balance method due to Wang, which was only used to obtain single soliton solutions of nonlinear evolution equations, and apply it to (2 + 1)-dimensional Broer-Kaup (BK) equations such that a Backlund transformation is found again. Considering further the obtained Backlund transformation, the relations are deduced among BK equations, well-known Burgers equations and linear heat equations. Finally, abundant multiple soliton-like solutions and infinite rational solutions are obtained from the relations.
Molecular Conformation and Structural Correlations of Liquid D-tert-Butanol at Room Temperature by Neutron Diffraction
Authors: Nath P. P. , Sarkar S. , Krishna P. S. R. , Joarder R. N.
Published: February 2015

An analysis of neutron diffraction data of liquid deuterated terr-butanol at room temperature to determine its molecular conformation is presented. Being a big molecule of 15 sites, the analysis is tricky and needs careful consideration. The resulting molecular parameters are compared with those obtained from other experimental data analysis and model calculations. The information about the intermolecular structural correlations, hydrogen-bonded molecular association in particular is also obtained from the diffraction data analysis. -PACS number: 61.25
Studies of Zero-field Splitting and its Pressure and Stress Dependence for Ni2+ in La2Mg3(NO3)12 · 24 H2O Crystal
Authors: Zheng Wen-Chen , Wu Shao-Yi , Dong Hui-Ning
Published: February 2015

By using the high-order perturbation formulas, the g factors g||
and g⊥, the zero-field splittings D and the pressure and uniaxial stress dependences of zero-field splitting are studied for Ni2+ ions in both Mg + sites of La2Mg3(NO3)12 • 24 H2O crystal. It is found that the local trigonal distortion angles ßi
of the two Ni + centers are only slightly different from the corresponding host ones, but the local angular compressibilities under pressure and stress for both Ni centers are quite different not only from the corresponding host ones, but also from each other.
The Influence of the Degree of Organization of Saturated Solutions on the Shape of the Solubility Isotherm
Authors: Eysseltová Jitka , Ebert Miroslav , Zbranek Vladimír
Published: February 2015

Special features of solubility isotherms of salt hydrates have been observed, from which the evidence of strong organization of saturated solutions of hydrates may be deduced. Often observed low contents of the non saturating component in the eutonic solution limiting the crystallization branch of hydrated salts is put into connection with this result. The composition of the respective eutonic solutions exhibits a correlation with the hydration entropy of the ions present in the ternary saturated solution.
Universal Scaling of Alpha Relaxation in Complex Liquids
Authors: Kurbatov A. , Drozd-Rzoska A. , Rzoska S. J. , Paluch M. , Malik P. , Zioło J. , Jadżyn J.
Published: February 2015

A plot is given, showing the result of a scaling analysis of dielectric loss curves containing, apart from low molecular glass former data (glycerol, dibutyl phtalate), also loss curves of the following liquid crystalline materials, mostly in the iso­ tropic phase: 4-(2-methylbutyl)-4'cyanobiphenyl (5*CB, supercooled isotropic phase), 4-cyano-4-n-alkyl biphenyls (nematogens 5CB and 8CB, isotropic phase), 4-(4-cyano-4-butylcyclohexyl)-4'-octylbiphenyl (laterally substituted nema-togen, isotropic phase), and 4-n-alkyl-4'-isothiocyanatobiphe-nyl (5 and 10 BT, isotropic and SmE phases). The plot applies the scaling formula originally proposed for glassforming, super­ cooled liquids [Dendzik et al.7]. The result supports the recent suggestion that dielectric relaxation in the isotropic phase of nematogens may show some features typical for "glassy" mate­ rials.
Insertionen in die Molybdän-Kohlenstoff-Bindung von η7-C7H7Mo(CO)2R-Spezies (R = CH3, C6H5); Darstellung und Charakterisierung von EO2 (E = S, Se, Te)- und Zn-Einschiebungsprodukten / Insertions into the Motybdenum-Carbon Bond of η7-C7H7Mo(CO)2R Species (R = CH3, C6H5) ; Synthesis and Characterization of EO2 (E = S, Se, Te) Insertion Products
Authors: Dell Winfried H. , Ziegler Manfred L.
Published: February 2015

The compounds η7-C7H7Mo(CO)2R (R = CH3, C6H5) were synthesized and characterized. The SO2-insertion into the Mo-C bond of the methyl and phenyl species was accomplished by condensing dry SO2 into the ether solutions of the compounds. The SeO2 and TeO2 insertion was only successful with the methyl compound activating the dioxides in a metal vapour apparatus. There is strong evidence that Zn can also be inserted in the Mo-C bond of η7-C7H7MO(CO)2CH3.
Darstellung und Charakterisierung von dreifach NR2-verbrückten Molybdänkomplexen des Typs η3-C7H7(CO)2Mo(μ–NR2)3Mo-η7-C7H7 / Synthesis and Characterization of Triply NR2-Bridged Molybdenum Complexes of the Type η3-C7H7(CO)2Mo(μ-NR2)3Mo-η7-C7H7
Authors: Dell Winfried , Ziegler Manfred L.
Published: February 2015

The mixed-valence compounds of composition C7H7(CO)2Mo(μ-NR2)3MoC7H7 (R=H, p-NO2-C6H4, C4H4) can be synthesized by reacting η7-C7H7Mo(CO)2Br with the corresponding sodium amides. The amido compound with R=H can also be obtained from η7-C7H7MO(CO)2CH3 in liquid ammonia. Reaction of the products with CH3OH yields the known complex η3)-C7H7(CO)2Mo(μ-OCH3)3Mo-η3-C7H7.
N-Methylsubstituierte Hydrazinderivate der Phosphorsäure aus Phenoxy-phosphoryl-dichlorid und aus Phenoxy-thiophosphoryl-dichlorid / N-Methyl Substituted Hydrazine Derivatives of Phosphoric Acid from Phenoxy-phosphoryl-dichloride and from Phenoxy-thiophosphoryl-dichloride
Authors: Bünger Thomas , Engelhardt Udo
Published: February 2015

C6H5OP(X)Cl2 (X=O, S) reacts with 1,2-dimethylhydrazine, 1,1-dimethylhydrazine or methylhydrazine, resp., to give the new dihydrazido derivatives la, 2a, 2b, or 3a and 3a-1, resp. Their 1H NMR and 31P NMR data are given.
An Investigation of AlCl3 Solutions in Ethers by 27Al NMR Spectroscopy
Authors: Nöth Heinrich , Rurländer Robert , Wolfgardt Peter
Published: February 2015

27Al NMR studies of AlCl3 solutions in diethyl ether reveal the presence of AlCl4 at high concentrations. This ion can also be recognized besides AlCl3·OR2 at low temperature in dilute solutions, while at 25 °C a single signal is observed, which represents the average of all species in solution. More extensive dissociation of AlCl3 results in tetrahydrofuran. The main species in equilibrium with one another are AlCl3·2THF, AlCl-
4 and AlCl2(THF)+
2.

Nearly quantitative dissociation to yield AlCl-
4 and [AlClL5]2+ occurs in dilute solutions of AlCl3 in monoglyme (L reprents one oxygen donor atom); at higher concentration an adduct AlCl3·L with Al in a tetrahedral environment is also present. This trend towards extensive dissociation is also observed in the solutions of AlCl3 in diglyme and triglyme. Relative peak areas are in agreement with the formation of a 1:1 electrolyte [AlCl2L4]+AlCl-
4 in diglyme, whereas additional dissociation into [AlClL5]2+ and AlCl-
4 occurs in triglyme.
Die Kristall- und magnetische Struktur von BaCrF5 / Crystal and Magnetic Structure of BaCrF5
Authors: Holler H. , Kurtz W. , Babel D. , Knop W.
Published: February 2015

A single crystal X-ray structure analysis of orthorhombic BaCrF5 (a = 1393.8(1), b = 571,1(1), c = 494,7(1) pm), which crystallizes in the structure type of BaGaF5, space group P212121, yielded Cr-F distances in the range of 187.3 to 194.9 pm, average 190.2 pm. Using powder neutron diffraction data taken at 2.2 K a G-type antiferromagnetic structure with spin alignment along the c direction of the lattice was worked out. Single crystal susceptibility data were consistent with this model and in addition showed a small net moment, probably due to spin canting, to be present below the Neel temperature of TN = 3.4 K. The orientation of this moment along the b axis is in accordance with the space group symmetry as well, chemical and magnetic cell being the same. From powder susceptibility data an exchange energy of -3.74 K (g = 2.02) was obtained by fitting Fisher's model. The low bridging angle of Cr-F-Cr = 137.4° within the cis corner-sharing chain of octahedra is made responsible for the weak antiferromagnetism in BaCrF5, which is compared to that of other chromium(III) fluorides.