Nonlinear Spin Dynamics in Nuclear Magnets

A method is developed for solving nonlinear systems of differential, or integrodifferential, equations with stochastic fields. The method makes it possible to give an accurate solution for an interesting physical problem: What are the peculiarities of nonlinear spin dynamics in nonequilibrium nuclear magnets coupled with a resonator? Evolution equations for nuclear spins are derived basing on a Hamiltonian with dipole interactions. The ensemble of spins is coupled with a resonator electric circuit. Seven types of main relaxation regimes are found: free induction, collective induction, free relaxation, collective relaxation, weak superradiance, pure superradiance, and triggered superradiance. The initial motion of spins can be originated by two reasons, either by an imposed initial coherence or by local spin fluctuations due to nonsecular dipole interactions. The relaxation regimes caused by the second reason cannot be described by the Bloch equations. Numerical estimates show good agreement with experiment.Comment: 1 file, 47 pages, LaTe

Effect of a dc magnetic field on the isothermal martensitic transformation in the Fe-24%Ni-4%Mn alloy

Effects of a dc magnetic field on the isothermal martensitc transformation in the region of the kinetic maximum of the Fe-24%Ni-4%Mn alloy and on the martemsitic transformation at a liquid-helium temperature were studied. It was shown that a dc magnetic field markedly affects the isothermal martensitic transformation. In particular, it shifts the temperature range of the martensitic transformation and the kinetic maximum toward higher temperatures and initiates the nucleation of isothermal martensite crystals and their subsequent growth upon isothermal holding. A dc magnetic field of a sufficiently high strength causes the intense formation of athermal martensite at the liquid-helium temperature, at which no transformation develops without a magnetic field. A comparison of the effects of the pulse and dc magnetic fields on the martensitic transformation in the alloys with martensite transformation isothermal kinetics was carried out

Current cytogenetic map of the common shrew, Sorex araneus L.: localization of 7 genes and 4 microsatellites

Here we present information on the assignment of 7 genes, ACADVL, ADORA3, ATP7A, MTMR4, MYH2, HBB, TSPAN-3, and 4 common shrew microsatellites to chromosomes of the common shrew (Sorex araneus) and on the current status of its cytogenetic map. Comparative mapping data were used for the analysis of evolutionary chromosomal rearrangements in the common shrew genome