30 research outputs found

    Origin of Pure Spin Superradiance

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    The question addressed in this paper is: What originates pure spin superradiance in a polarized spin system placed inside a resonator? The term "pure" means that no initial coherence is imposed on spins, and its appearance manifests a purely self-organized collective effect. The consideration is based on a microscopic model with dipole spin interactions. An accurate solution of evolution equations is given. The results show that the resonator Nyquist noise does not play, contrary to the common belief, any role in starting spin superradiance, but the emergence of the latter is initiated by local spin fluctuations. The decisive role of nonsecular dipole interactions is stressed.Comment: 1 file, 13 pages, RevTe

    Features of innovative personnel management of service companies in the period of implementation of organizational changes

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    © Authors. In the conditions of development and improvement of management systems in organizations of the service sector, the requirements to the quality of labor and the qualification of personnel are increasing, which is an essential condition for achieving competitive advantages. The relevance of the research of the features of innovative personnel management in the service sector is determined by the growing role of this industry in the modern economy. Based on the use of theoretical and empirical methods, conditions and mechanisms for the formation of an innovative system of training/development of personnel at service enterprises were identified. The paper substantiates the priority tasks of personnel management in the context of the basic concepts of organizational change. As a result of the study, a program to improve the skills and trainings for employees of service enterprises, taking into account the characteristics of their work activities, was developed. An author's two-component model for estimating investment in human capital is proposed, which reflects the personal development of employees

    Nonlinear Spin Dynamics in Ferromagnets with Electron-Nuclear Coupling

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    Nonlinear spin motion in ferromagnets is considered with nonlinearity due to three factors: (i) the sample is prepared in a strongly nonequilibrium state, so that evolution equations cannot be linearized as would be admissible for spin motion not too far from equilibrium, (ii) the system considered consists of interacting electron and nuclear spins coupled with each other via hyperfine forces, and (iii) the sample is inserted into a coil of a resonant electric circuit producing a resonator feedback field. Due to these nonlinearities, coherent motion of spins can develop, resulting in their ultrafast relaxation. A complete analysis of mechanisms triggering such a coherent motion is presented. This type of ultrafast coherent relaxation can be used for studying intrinsic properties of magnetic materials.Comment: 1 file, LaTex, 23 page

    Nonadiabatic Dynamics of Atoms in Nonuniform Magnetic Fields

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    Dynamics of neutral atoms in nonuniform magnetic fields, typical of quadrupole magnetic traps, is considered by applying an accurate method for solving nonlinear systems of differential equations. This method is more general than the adiabatic approximation and, thus, permits to check the limits of the latter and also to analyze nonadiabatic regimes of motion. An unusual nonadiabatic regime is found when atoms are confined from one side of the z-axis but are not confined from another side. The lifetime of atoms in a trap in this semi-confining regime can be sufficiently long for accomplishing experiments with a cloud of such atoms. At low temperature, the cloud is ellipsoidal being stretched in the axial direction and moving along the z-axis. The possibility of employing the semi-confining regime for studying the relative motion of one component through another, in a binary mixture of gases is discussed.Comment: 1 file, 17 pages, RevTex, 2 table

    Nonlinear Spin Dynamics in Nuclear Magnets

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    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

    Features of innovative personnel management of service companies in the period of implementation of organizational changes

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    © Authors. In the conditions of development and improvement of management systems in organizations of the service sector, the requirements to the quality of labor and the qualification of personnel are increasing, which is an essential condition for achieving competitive advantages. The relevance of the research of the features of innovative personnel management in the service sector is determined by the growing role of this industry in the modern economy. Based on the use of theoretical and empirical methods, conditions and mechanisms for the formation of an innovative system of training/development of personnel at service enterprises were identified. The paper substantiates the priority tasks of personnel management in the context of the basic concepts of organizational change. As a result of the study, a program to improve the skills and trainings for employees of service enterprises, taking into account the characteristics of their work activities, was developed. An author's two-component model for estimating investment in human capital is proposed, which reflects the personal development of employees

    Tick-borne Encephalitis Virus in Arthropod Vectors in the Far East of Russia

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    Isolates of tick-borne encephalitis virus (TBEV) from arthropod vectors (ticks and mosquitoes) in the Amur, the Jewish Autonomous and the Sakhalin regions as well as on the Khabarovsk territory of the Far East of Russia were studied. Different proportions of four main tick species of the family Ixodidae: Ixodes persulcatus P. Schulze, 1930; Haemaphysalis concinna Koch, 1844; Haemaphysalis japonica douglasi Nuttall et Warburton, 1915 and Dermacentor silvarum Olenev, 1932 were found in forests and near settlements. RT-PCR of TBEV RNA in adult ticks collected from vegetation in 1999-2014 revealed average infection rates of 7.9+/-0.7% in I. persulcatus, of 5.6+/-1.0% in H. concinna, of 2.0+/-2.0% in H. japonica, and of 1.3+/-1.3% in D. silvarum. Viral loads varied in a range from 10(2) to 10(9) TBEV genome-equivalents per a tick with the maximal values in I. persulcatus and H. japonica. Molecular typing using reverse transcription with subsequent real time PCR with subtype-specific fluorescent probes demonstrated that the Far Eastern (FE) subtype of TBEV predominated both in mono-infections and in mixed infection with the Siberian (Sib) subtype in I. persulcatus pools. TBEV strains of the FE subtype were isolated from I. persulcatus, H. concinna and from a pool of Aedes vexans mosquitoes. Ten TBEV strains isolated from I. persulcatus from the Khabarovsk territory and the Jewish Autonomous region between 1985 and 2013 cluster with the TBEV vaccine strain Sofjin of the FE subtype isolated from human brain in 1937. A TBEV strain from H. concinna collected in the Amur region (GenBank accession number KF880803) is similar to the vaccine strain 205 isolated in 1973 from I. persulcatus collected in the Jewish Autonomous region. The TBEV strain Lazo MP36 of the FE subtype isolated from a pool of A. vexans in the Khabarovsk territory in 2014 (KT001073) differs from strains isolated from 1) I. persulcatus (including the vaccine strain 205) and H. concinna; 2) mosquitoes [strain Malishevo (KJ744034) isolated in 1978 from Aedes vexans nipponii in the Khabarovsk territory]; and 3) human brain (including the vaccine strain Sofjin). Accordingly, in the far eastern natural foci, TBEV of the prevailing FE subtype has remained stable since 1937. Both Russian vaccines against TBE based on the FE strains (Sofjin and 205) are similar to the new viral isolates and might protect against infection
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