Ion beam parameters of a plasma accelerator

The aim of the present investigation was to determine the dependences of the current density, the energy, and the divergence of the ion beams of an UZDP-type source (a plasma accelerator with closed electron drift in the accelerator channel and an extended zone of ion acceleration) on the parameters which determine its performance, and to establish qualitative relationships between these values.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 20–24, February, 1987.     

On the spectrum of the Steklov problem in a domain with a peak

We consider the spectral Steklov problem in a domain with a peak on the boundary. It is shown that the spectrum on the real nonnegative semi-axis can be either discrete or continuous depending on the sharpness of the exponent.     

Solvent effects on the absorption spectrum and recombination kinetics of diphenylcarbonyl oxide

The absorption spectra and rate constants of diphenylcarbonyl oxide recombination in a series of solvents and their binary mixtures were determined by flash photolysis. An increase in the solvent polarity causes hypsochromic shift of the maximum in the absorption spectrum of Ph₂COO. The analysis of the solvent effect on the recombination rate constant in terms of the four-parameter Koppel—Palm equation shows that the reactivity of carbonyl oxide depends on both specific and non-specific solvations. Quantum chemical B3LYP/6-31G(d) calculations of H₂COO and PhHCOO carbonyl oxides as well as the complexes of H₂COO with acetonitrile and ethylene in different media were performed using a polarized continuum model.     

Perturbations of solutions of the sinorini problem for a second-order scalar equation

Translated from Matematicheskie Zametki, Vol. 47, No. 1, pp. 115–126, January, 1990.     

The Essence of “Black Holes” for Elastic Waves in Solids with Cuspidal Sharpening

Doklady Physics - The effect of a “black hole” for elastic waves, discovered by M.A. Mironov and examined in detail by followers, is usually associated with propagation of elastic waves...     

Use of the energy criterion of fracture to determine the shape of a slightly curved crack

An asymptotic formula is obtained for the total-energy increment during quasistatic growth of a semiin finite crack in an anisotropic elastic plane under complex loading. It is assumed that the shear loads are much larger than the tearing loads. The shape of the slightly curved crack was determined using the Griffith criterion in two versions: global and local. It is shown, in particular, that the first version leads to an improbable result. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 5, pp. 119–130, September–October, 2006.     

Mannich products of kojic acid and N-heterocycles and their Ru(II)-arene complexes: Synthesis, characterization and stability

Ru(II)-η⁶-p-cymene compounds bearing pyrone-derived ligands, which were obtained by Mannich reaction with piperidine and related analogues, have been synthesized. The compounds were characterized by NMR spectroscopy, mass spectrometry, thermogravimetric analysis and in the case of 2-(2,6-dimethyl-morpholin-4-ylmethyl)-3-hydroxy-6-hydroxymethyl-pyran-4-one by X-ray diffraction analysis. The chlorido complexes are prone to aquation in aqueous solution which results in the formation of dimers. Dimer formation can be inhibited by in situ replacement of the chlorido ligand by imidazole yielding compounds which are significantly more stable in water, as demonstrated by ¹H NMR spectroscopy.     

Synthesis of CeO<Subscript>2</Subscript>-ZrO<Subscript>2</Subscript> hydrosols via peptization at room temperature

A procedure is developed for the synthesis of concentrated CeO₂-ZrO₂ hydrosols based on the peptization of a precipitate obtained by the hydrolysis of a cerium nitrate-zirconium oxynitrate mixture. The time intervals and optimum [H⁺]/[Me ⁿ⁺] molar ratios giving rise the formation of CeO₂-ZrO₂ hydrosols stable to aggregation with a narrow particle size distribution are established. The size, shape, density, and phase composition of the hydrosol particles are determined.     

The Dirichlet problem for non‐divergence parabolic equations with discontinuous in time coefficients in a wedge

We consider the Dirichlet problem in a wedge for parabolic equation whose coefficients are measurable function of t. We obtain coercive estimates in weighted ‐spaces. The concept of “critical exponent” introduced in the paper plays here the crucial role. Various important properties of the critical exponent are proved. We give applications to the Dirichlet problem for linear and quasi‐linear non‐divergence parabolic equations with discontinuous in time coefficients in cylinders , where Ω is a bounded domain with an edge or with a conical point.