NMR and spin-lattice relaxation rate of89Y,63Cu in radiation disordered YBa2Cu3O6.9

NMR line shifts and spin-lattice relaxation rates of⁸⁹Y and⁶³Cu in YBa₂Cu₃O_6.9 were measured in disordered samples irradiated by fast neutrons with a fluence of: ?=5·10¹⁸ cm^?2 (T _c ^ons =70 K), ?=1.2·10¹⁹ cm^?2 (T _c ^ons =20 K), in order to investigate the evolution of spin susceptibility χ_S under irradiation. According to the data obtained, χ_S decreases markedly as structural disorder accumulates in the samples. The variation of χ_S is related closely to that observed in oxygen-depleted YBa₂Cu₃O_7?δ compounds with nearly the sameT _c value. The data for yttrium display some features that are absent in oxygen-depleted samples. The different temperature dependence of the⁸⁹Y and⁶³Cu Knight shifts and the increase of the⁸⁹Y spin-lattice relaxation rate in irradiated samples are discussed in terms of the electron localization effects arising in the CuO₂ planes due to the radiation-induced structural disorder.     

Low-frequency solutions of the wave equations in Schwarzchild space

A method is proposed for study of the low-frequency asymptote of wave-equation solutions against the background of a Schwarzchild metric, which permits separation of the major nonanalytic portions of the coefficients relating the asymptote of the solutions at the horizon and at spatial infinity, and also corresponding to a portion of Green's function in the vicinity of zero frequency. The proposed method permits a strict justification of results obtained in earlier studies of the low-frequency asymptote.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 34–39, September, 1979.The author sincerely thanks K. A. Piragas for his interest in tim study, and the members of the gravitational studies seminar of the Ukrainian Republic Standardization and Metrology Center and the members of the Little seminar of the gravitation section of the Siberian Division, Academy of Sciences of the USSR, for their interest in the study and valuable advice.     

Reconstruction of scattering properties of rough air-dielectric boundary

The article is devoted to elaboration of the method of reconstruction of rough surface scattering properties. The object with rough surface is made of transparent dielectric material. Typically these properties are described with bi-directional scattering distribution function (BSDF). Direct measurement of such function is either impossible or very expensive. The suggested solution provides physically reasonable method for the rough surface BSDF reconstruction. The method is based on Monte-Carlo ray tracing simulation for BSDF calculation. Optimization technique is further applied to correctly reconstruct the BSDF. The results of the BSDF reconstruction together with measurement results are presented in the article as well.     

Inhibition of the receptor-mediated virion attachment to a lipid membrane

The forefront of the anti-viral defence is sometimes aimed at virion attachment to a host membrane. This step or, more specifically, virion contacts with cellular membrane receptors (or, e.g., glycolipids) can be inhibited by antibodies (or specially chosen or designed compounds) via their association with virions. In this case, the full-scale attachment of virions to a host membrane occurs via a subtle interplay of the formation and rupture of multiple virion-inhibitor and virion-receptor bonds. We present a kinetic model describing this interplay and illustrating general trends in the process under consideration.     

A generic 3D kinetic model of gene expression

Recent experiments show that mRNAs and proteins can be localized both in prokaryotic and eukaryotic cells. To describe such situations, I present a 3D mean-field kinetic model aimed primarily at gene expression in prokaryotic cells, including the formation of mRNA, its translation into protein, and slow diffusion of these species. Under steady-state conditions, the mRNA and protein spatial distribution is described by simple exponential functions. The protein concentration near the gene transcribed into mRNA is shown to depend on the protein and mRNA diffusion coefficients and degradation rate constants.     

Comprehensive Analysis of the Liquid Fraction of Car Tire Pyrolysis Products by Gas Chromatography–Mass Spectrometry

Russian Journal of Applied Chemistry - The liquid fraction of tire pyrolysis products was comprehensively analyzed by gas chromatography–mass spectrometry and two-dimensional gas...     

Improved energies for the 5.2 keV M1 and 42.0 keV M2 nuclear transitions in 83Rb

The European Physical Journal A - The low-energy electron spectrum following the decay of 83Sr was analysed at high instrumental resolution by an electrostatic spectrometer. Significantly improved...