Rare-earth metal 8-hydroxyquinolinate complexes as materials for organic light-emitting diodes

Rare-earth metal 8-hydroxyquinolinates (q) were studied as emission layers for organic light-emitting diodes. Compounds Dyq₃, Tbq₃, and Smq₃ possess weak electroluminescence due to the emission of the ligand, and the electroluminescence of Hoq₃, Tmq₃, and Ybq₃ is due to electronic transitions of the lanthanide ion. The best electroluminescence characteristics were demonstrated by Scq₃ and Yq₃. The power efficiency of the organic light emitter based on ITO/TPD/Scq₃/Yb (ITO is tin-alloyed indium oxide, TPD is N,N′-bis(3-methylphenyl)-N,N′-diphenylbenzidine) is 2.6 lm W⁻¹ at a luminance of the device of 300 cd m⁻².     

Sequential Estimation of the Parameters in a Trigonometric Regression Model with the Gaussian Coloured Noise

This paper considers the estimation problem for a trigonometric regression model with the noise specified by the Ornstein–Uhlenbeck process with unknown parameter. We propose a sequential procedure which ensures a prescribed mean square precision uniformly in the nuisance parameter. The asymptotic behaviour of the procedure duration mean has been studied. This revised version was published online in August 2006 with corrections to the Cover Date.     

Influence of UV Pretreatment on Thermooxidative Degradation of Poly(Methyl Methacrylate) Films with Fullerene C<Subscript>60</Subscript> or C<Subscript>70</Subscript>

Wariation of the concentration of fullerenes C₆₀ and C₇₀ in poly(methyl methacrylate) films under UV exposure in atmospheric oxygen was studied. The mechanism of the influence exerted by addition of some photostabilizing polymers and xanthene dyes on the photooxidative degradation of fullerene in the polymer matrix was analyzed.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 6, 2005, pp. 1038–1042.Original Russian Text Copyright © 2005 by Troitskii, Khokhlova, Konev, Denisova, Novikova, Lopatin.     

A mathematical description of redox sorption of molecular oxygen taking into account the degree of metal dispersity in an electron-ion exchanger

The paper presents a physicochemical model of the redox sorption of molecular oxygen from water by a metal-containing electron-ion exchanger. The model takes into account the dispersity of metal particles, the special features of their chemical oxidation, and interrelation between the total process rate and the properties of the ion-exchange matrix. This model was used to formulate the problem mathematically, obtain a numerical solution, and theoretically analyze it as depending on the main parameters of the sorption system. A criterion was introduced for estimating the contributions of the diffusion and kinetic stages taking into account the dispersity of metal particles.     

Methodology for Determination of the Key Parameters of Conjugated Polymer Electrodeposition,Based on a Combination of Spectroelectrochemistry and Electrochemical Quartz Crystal Microbalance

Russian Journal of Electrochemistry - Methodology based on a combination of experimental data obtained by in situ methods of spectroelectrochemistry and electrochemical quartz crystal microbalance...     

Calculation of photoemission characteristics of cubic K3Sb

A three-step model of photoelectron emission is used to calculate the quantum efficiency and the energy distribution functions of emitted electrons with allowance for the scattering of the excited electrons leading to the production of electron-hole pairs. The calculated quantum efficiency is compared with experimental data in the visible part of the spectrum. The correlation between the structure of the photoemission characteristics and the density of the electron states is discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 20–25, October, 1980.     

Optical properties of cubic K3Sb

A number of optical characteristics of the crystal K₃Sb of cubic structure (the complex dielectric permeability function, the density of electron states, the refractive and absorptive indices, the optical density of the material) are computed on the basis of the electron energy spectrum calculated by the pseudopotential method taking account of nonlocality and spin-orbital interaction. Direct and indirect transition models to describe the optical excitation of electrons are discussed. Theoretical and experimental curves are compared.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 33–39, February, 1979.     

Reductive sorption of molecular oxygen from water on silver-KU-23 sulfo-cation exchanger nanocomposites in different ionic forms

New silver-containing nanocomposites different in their dispersity of metal were synthesized on the basis of strongly and weakly basic anion-exchange resins. The chemical activity of the nanocomposites with respect to oxygen dissolved in water was investigated. It was shown that silver nanoparticles in samples based on strongly basic anion exchangers and weakly basic anion exchangers in the NO₃⁻ salt form are not oxidized by oxygen; for weakly basic matrices in the free amine form, this process occurs to only a small extent. The resistance to oxygen is explained by inhibition of processes of formation of silver oxides. Nanocomposites based on strongly basic anion-exchange resins are recommended for testing as to catalytic activity.     

On the collection of spectral multiplicities {2, 4, …, 2 n } for totally ergodic ℤ2-actions

The paper is devoted to the realization of collections of spectral multiplicities for ergodic ?²-actions. Sufficient conditions ensuring the realizability of multiplicities of the form {2, 4, …, 2 ⁿ } are given.