Bp stars in OrionOB1 association

A total of 85 CP stars of various types are identified among 814 members of the Orion OB1 association. We selected 59 Bp stars, which account for 13.4% of the total number of B type stars in the association. The fraction of peculiar B type stars in the association is found to be twice higher than that of peculiar A type stars. Magnetic field are found in 22 stars, 17 of them are objects with anomalous helium lines. No significant differences are found between the field strengths in the Bp type stars of the association and Bp type field stars. We identified 17 binaries, which make up 20% of the total number of peculiar stars studied which is the standard ratio for CP stars.Comment: Proceedings of IAUS 30

Quantum phase transition in HTSC thick films: YBa2Cu 3O x, YBa2Cu3O x (5 % Ag-Doped) in a Strong Pulsed Magnetic Field up to 32 T at low temperatures (58-100 K), current densities and stress-effect

We have researched the influence of pulsed magnetic fields up to 32 T on the magneto-resistance of thick films (50 Mk) of YBa2Cu3O x and YBa2Cu3O x (5 % Ag-doped) that were produced from synthesized powders. (Figs. 1-9): concentrate with 6.85-6.9 % O2 and a tail fraction 6.5-6.6 % O2. We observed a linear plot at currents of more than 1 mA at 77 K in YBa2Cu 3O x (5 % Ag-doped) at B>5 T and in the concentrate YBa2Cu3O x samples with I=1 mA, T=68.2 K. Pulsed magnetic fields up to 32 T, at I=1 mA had practically no influence on the value of the magneto-resistance in the concentrate YBa2Cu 3O x specimens at T=57.9 K and up to 17 T for YBa 2Cu3O x (5 % Ag) at 77 K (Meissner effect). However, for B>17 T, YBa2Cu3O x (5 % Ag) at 77 K demonstrates a tendency toward lower resistance. In the presence to 10 pulses in a cyclic pulsed magnetic field of 32 T, there is a sharp change of magnetic properties of an HTSC that can lead to nontrivial changes in the transition temperature, due to the strong mechanic stresses, sharp change value structure, and because one of the phases becomes superconducting (Figs. 3A, 3B). The behavior of the magnetoresistance of S-N-S contacts in pulsed magnetic fields is described via the system's parallel resistance, R n, and the inductance, L S-N-S. Analysis of microscopic models of quantum phase transitions was made in a granular superconductor in an attempt to explain the results on the studied HTSC-films and to give a physical interpretation to the deduced parameters of some experiments on the basis of "spin (vortex) glass" (vortex ice). © 2012 Springer Science+Business Media New York

Generalized functionally-invariant representation of processes in lines with small losses

Розглянуто диференціальне рівняння, що описує нестаціонарний струм у довгій лінії з малими втратами. Методом багатьох масштабів синтезовано наближений загальний розв’язок у вигляді комбінації двох затухаючих хвиль.Differential equation that describes a nonstationary current in a long line with small losses is considered. Approximate general solution as a combination of two damped waves is synthesized by the method of many scales

Spin-orientation-dependent spatial structure of a magnetic acceptor state in a zincblende semiconductor

The spin orientation of a magnetic dopant in a zincblende semiconductor strongly influences the spatial structure of an acceptor state bound to the dopant. The acceptor state has a roughly oblate shape with the short axis aligned with the dopant's core spin. For a Mn dopant in GaAs the local density of states at a site 8 angstrom away from the dopant can change by as much by 90% when the Mn spin orientation changes. These changes in the local density of states could be probed by scanning tunneling microscopy to infer the magnetic dopant's spin orientation.Comment: 5 pages, 4 figure