Nonreciprocal effects in light reflection by a moving medium

Nonreciprocal effects in light reflection by a medium moving along an interface are considered in a weakly relativistic approximation. It is found that nonreciprocal effects are anomalously large in the vicinity of the Brewster and the total-internal-reflection (TIR) angles when light is reflected by transparent moving media. These effects exceed considerably (by several orders of magnitude) the ratio of the velocity of the reflecting medium to the velocity of light and can be proportional to rather than to under certain conditions. We show new possibilities for the creation a method for investigation of the structure of nonuniform flows with a very small spatial scale (less than one millimeter). This method is based on measurement of amplitude and phase nonreciprocities in light reflection by these flows.Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 11, pp. 1146–1157, November, 1995.     

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.     

Electrical conductivity of solutions of the LiIO3-HIO3-H2O system

The electrical conductivity of aqueous LiIO₃ solutions and solutions of the LiIO₃-HIO₃-H₂O system is measured over a wide range of compositions at 25, 50, and 75°C. Isothermal surfaces of electrical conductivity are mapped, and the activation energies of conductivity are calculated. The conductivity isotherms in the LiIO₃-H₂O and HIO₃-H₂O boundary binary systems and in mixed solutions along sections with fixed electrolyte ratios each have a maximum as a function of electrolyte concentration. It is assumed that structure reorganization occurs in solutions in the concentration range corresponding to the peak conductivity. Proton migration features in the solutions in question are considered.     

Existence and uniqueness theorems for A -regular generalized solutions of the first boundary-value problem for (A,674-01674-01674-01) — Elliptic equations

For second-order quasilinear degenerate elliptic equations, having the structure of -elliptic equations in a bounded domain Rⁿ, n2, one establishes theorems of existence and uniqueness for the generalized solutions of the first boundary-value problem, bounded together with their A -derivatives of first order and also of first and second order. The case of linear second-order -elliptic equations are separately considered.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 115, pp. 83–96, 1982.