Change in structure and properties of carbon steels bombarded by a 10−5 to 10−4 second high-energy electron beam

We consider the hardening characteristics and features of the structural and phase transformations in carbon steel (0.7% C) quenched from the melt using an electron beam with electron energy 130–180 keV, pulse duration 10–200 msec and power density 10⁶ to 10⁷ W/cm². We have observed that maximum hardening is achieved for pulse duration 40 msec. The nonmonotonic character of the dependence of the degree of hardening on the pulse duration is connected with the substantial effect of the beam parameters on the phase composition and morphology of the rapidly quenched structures.Institute of Power Electronics, Siberian Branch, Russian Academy of Sciences; Tomsk State Architectural Design Academy. Institute of the Physics of Strength and Materials Science, Siberian Branch, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, p. 42–50, October, 1995.     

On the maximum principle for doubly nonlinear parabolic equations

For a general class of doubly nonlinear parabolic equations, some versions of the maximum principle are established. They play an important role in studying the regularity of generalized solutions of such equations. In particular, the results obtained can be used in studying equations of the form $$\frac{{\partial u}}{{\partial t}} - div\{ |u|^l |\nabla u\} = 0, m > 1, l > 1 - m.$$ which have numerous applications in the mechanics of continuous media. Bibliography: 17 tiles.     

Methylation of the cyclic homolog of xanthine

Alkylation of the cyclic homolog of xanthine in the methyl iodide-sodium hydride system as a function of the reagent-alkylating system ratio yields different products: for a 13 ratio of reagents, a homolog of caffeine is formed, while for a 12 ratio, a homolog of theobromine is formed. In contrast to xanthine, methylation of its cyclic homolog initially takes place at the imidazole ring and occurs in the sequence N₍₁₎, N₍₄₎, N₍₇₎.A. V. Bogatskii National Academy of Sciences of Ukraine, Odessa 270080. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 701–703, May, 1998.     

Effect of interference of quantum states on the broadening of energy levels in a strong electromagnetic field

The wave equation, written down for -functions averaged over the gauge, is solved within the resonance approximation for a number of low levels of a hydrogen-like atom, located in a strong electromagnetic field and undergoing impact action. It is shown that the interference of quantum states, resulting from the interaction of the atom with its surrounding, may lead, depending on the conditions, to a further dependence of the broadening or narrowing of spectral line contours on the external field intensity.Omsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 8–12, November 1993.     

The photodissociation of molecules near the ionisation threshold

The photodissociation (PD) of the moleculeXY near the ionisation threshold is considered within the framework of the multichannel quantum defect theory. The general analytical dependence, determining the relation between the PD amplitude, the adiabatic amplitudes of dipole transitions and elements of the collisions matrix describing the associative ionisation (X+Y→e ^?+XY ⁺) and resonance scattering of atoms (X+Y→X′+Y′), has been obtained. The collisions matrix is determined by the system of algebraic equations and is expressed via the parameters which can be reconstructed from the molecule terms adiabatic picture. The obtained expressions can be used in case of a random number of Rydberg and dissociative channels. The role of the resonance mechanism of the molecules intermediate predissociative and autoionisational states population has been investigated. The peculiarities of the PD spectra structure for different physical situations have been studied. It has been shown that the Rydberg continuum states population increases the process general efficiency (the PD cross-section averaged over resonances increases). The NO molecule near-threshold PD, proceeding through thenpπ Rydberg states is calculated.     

Photoelectron spectra andab initio calculations of the electronic structure of amino-n-sulfenyl chlorides

The electronic structure of some amino-N-sulfenyl chlorides and related compounds is studied by photoelectron spectroscopy and ab initio calculations. Similar values of IP(n _S ) and IP(n _N ) and the total energy minimum indicate that in stable conformations the n _S and n _N orbitals are orthogonal. These conformers are characterized by an effective n_N-σ _S-Cl ^* interaction. The relationship between the intramolecular shift of charge and ionization potential values and the spatial structure of amino-N-sulfenyl chlorides is analyzed. A. E. Arbuzov Institute of Organic and Physical Chemistry, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 2, pp. 69–73, March–April, 1994. Translated by L. Smolina     

Sorption–Spectrometric Determination of Palladium in Chloride Solutions

A sorption–spectrometric method was developed for the determination of palladium in solutions of complex composition using cellulose filters impregnated with trioctylamine with the subsequent formation of the colored compound of palladium with 4-(2-pyridylazo)resorcinol on the filter. It was demonstrated that conditions for the preconcentration of palladium coincide with conditions for the formation of colored compounds (green and red forms of palladium complexes) in the sorbent phase. The highest selectivity is observed for the formation of the green form; in this case, the determination of palladium is not affected by the interference from large amounts of concomitant elements (macrocomponents of ores). Palladium was determined on filters by diffuse reflectance spectrometry with the calculation of chromaticity characteristics and by a test scale. The detection limits were 0.5 (green form) and 0.3 (red form) g of palladium on the filter. High precision of results of the determination of palladium (RSD < 5%) is attained in a wide range of its concentrations.     

Recyclization of tetranitrodibenzo-18-crown-6 and tetranitrodibenzo-24-crown-8 into monobenzocrown ethers

The benzo-9-crown-3 and benzo-12-crown-4 derivatives are formed by reaction of tetranitrodibenzo-18-crown-6 and tetranitrodibenzo-24-crown-8, respectively, with sodium methoxyethoxide in DMSO at 20C.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1474–1476, November, 1990.