Photometric Determination of N-Phenyl-Substituted Monomaleimides as Aci Forms of Their Nitro Compounds

A procedure is developed for the photometric determination of three N-phenyl-substituted monomaleimides as aci forms of their nitro compounds obtained by preliminary hydrolysis, nitration, and subsequent interaction with alkali. As a result, an intense bright-yellow color of the reaction product is developed.     

Erratum to: Characterization of the Unit Ball in C<Superscript><Emphasis Type="Italic">n</Emphasis></Superscript> Among Complex Manifolds of Dimension <Emphasis Type="Italic">n</Emphasis>

We correct the formulation of the main result in our earlier paper.      

Numerical Simulation of the Unsteady Laminar Flow Past a Circular Cylinder with a Perforated Sheath

The unsteady two-dimensional laminar flow past a circular cylinder encased in a perforated sheath is numerically simulated. On the basis of the calculated results a technique for controlling the wake flow by diverting a portion of the flow from the forward stagnation point through internal ducts to orifices in the sheath located in the separation zone, is analyzed.     

The geometry and electronic structure of the ionic defect in a chain of water molecules between a donor and an acceptor

Quantum chemical calculations of the molecular complexes (NH₃)₃Zn²⁺...(H₂O)_n3...NH₃ (C_n, n=11, 16, 21, and 30) that model the proton donor-aqueous chain-acceptor channel in biological molecules were performed. Periodicity of O-H bond lengths in water chains and charges of the H atoms of H-bonds observed earlier were discussed. In C_n complexes, the geometry and electronic structure of the ionic defect in the aqueous chain with an excess proton were studied. The distributions of O-H bond lengths and charges on H-bond H atoms in the region of the ionic defect obtained in ab initio (B3LYP/6-31+G^**) and semiempirical (PM3) calculations are compared. The influence of aqueous chain extension, the position of the protonated water molecule, and the mobility of water molecules in the chain on the structure of the ionic defect was analyzed.     

Influence of oxygen pressure on the photochemical oxidation of phenol

The influence of the oxygen pressure on the photochemical oxidation of phenol is investigated. It is shown that raising the oxygen pressure from 0.1 to 0.7 MPa leads to an increase in the photochemical oxidation of phenol by a factor of approximately 3.7.     

Functional equations for transfer-matrix operators in open Hecke chain models

We consider integrable open chain models formulated in terms of the generators of affine Hecke algebras. We use the fusion procedure to construct the hierarchy of commutative elements, which are analogues of the commutative transfer matrices. These elements satisfy a set of functional relations generalizing functional relations for a family of transfer matrices in solvable spin chain models of the U_q(gl(n|m)) type. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 150, No. 2, pp. 219–236, February, 2007.     

Low-temperature conduction of a system of tunnel-coupled quantum dots in YBaCuO and LaSrMnO dielectric films

This paper reports on new results of experimental investigations into the nature of the electrical resistivity ρ(T) ? const at T<T _crit for YBaCuO and LaSrMnO dielectric films. The films are prepared by pulsed laser deposition and contain nanocrystalline clusters with metallic conductivity. Dependences of the electrical resistivity ρ(T) ? const are observed for the epitaxial films YBaCuO (T _crit=10 K) with a tetragonal structure after exposure to KrF excimer laser radiation and for the as-prepared amorphous films LaSrMnO (T _crit?160 K). The effect of interest (ρ(T) ? const) manifests itself in the case when the optical spectra of the studied samples contain portions attributed to absorption by free charge carriers. The inference is made that this effect can be associated with tunneling conduction in a system of quantum dots.