3,535 research outputs found
Magnetic properties and magnetostructural phase transitions in Ni2+xMn1-xGa shape memory alloys
A systematic study of magnetic properties of Ni2+xMn1-xGa (0 \le x \le 0.19)
Heusler alloys undergoing structural martensite-austenite transformations while
in ferromagnetic state has been performed. From measurements of spontaneous
magnetization, Ms(T), jumps \Delta M at structural phase transitions were
determined. Virtual Curie temperatures of the martensite were estimated from
the comparison of magnetization in martensitic and austenitic phases. Both
saturation magnetic moments in ferromagnetic state and effective magnetic
moments in paramagnetic state of Mn and Ni atoms were estimated and the
influence of delocalization effects on magnetism in these alloys was discussed.
The experimental results obtained show that the shift of martensitic transition
temperature depends weakly on composition. The values of this shift are in good
correspondence with Clapeyron-Clausius formalism taking into account the
experimental data on latent heat at martensite-austenite transformations.Comment: 7 pages, 8 figure
Algebraic Model for scattering in three-s-cluster systems. I. Theoretical Background
A framework to calculate two-particle matrix elements for fully
antisymmetrized three-cluster configurations is presented. The theory is
developed for a scattering situation described in terms of the Algebraic Model.
This means that the nuclear many-particle state and its asymptotic behaviour
are expanded in terms of oscillator states of the intra-cluster coordinates.
The Generating Function technique is used to optimize the calculation of matrix
elements. In order to derive the dynamical equations, a multichannel version of
the Algebraic Model is presented.Comment: 20 pages, 1 postscript figure, submitted to Phys. Rev.
Interaction of Radiation and a Relativistic Electron in Motion in a Constant Magnetic Field
The work examines the effect of multiple photon emission on the quantum
mechanical state of an electron emitting synchrotron radiation and on the
intensity of that radiation. Calculations are done with the variant of
perturbation theory based on the use of extended coherent states. A general
formula is derived for the number of emitted photons, which allows for taking
into account their mutual interaction. A model problem is used to demonstrate
the absence of the infrared catastrophe in the modified perturbation theory.
Finally, the electron density matrix is calculated, and the analysis of this
matrix makes it possible to conclude that the degree of the elecron's spatial
localization increases with the passage of time if the electron is being
accelerated.Comment: 29 pages, no figure
Técnica, princÃpios e caracterÃsticas de avaliação da eficiência econômica da construção e reconstrução de rodovias
Efficiency assessment technique of capital investments in construction and reconstruction of highways is described in this article. Despite the degree of readiness of the methodical device, specialized construction norms of VSN 21-83 focused on implementation of such assessment were not widely adopted in view of the difficulties arising in the course of collecting basic data, their reliability and quality. The present article contains the characteristics of the grouped components and evaluation criteria, in particular, the description of settlement indicators in a section of the intra-transport, extra-transport and social and economic effects resulting from capital investments in linear objects of road infrastructure. On a concrete example the assessment procedure and calculations of summary economic indicators for groups and for the project in general is shown. What shows is a possibility of application of rather difficult technique and its efficiency as scientific tool of complex assessment for the solution of applied tasks in road construction. And use of departmental construction norms in combination with the dynamic methods of assessment based on the analysis of cash flows can increase substantially scientific validity of administrative decisions and quality of investment projects in the field of development of road infrastructure.En este artÃculo se describe la técnica de evaluación de la eficiencia de las inversiones de capital en la construcción y reconstrucción de carreteras. A pesar del grado de preparación del dispositivo metódico, las normas de construcción especializadas de VSN 21-83 enfocadas en la implementación de dicha evaluación no se adoptaron ampliamente en vista de las dificultades que surgen en el curso de la recopilación de datos básicos, su confiabilidad y calidad. El presente artÃculo contiene las caracterÃsticas de los componentes agrupados y los criterios de evaluación, en particular, la descripción de los indicadores de asentamiento en una sección del transporte interno, transporte extra y los efectos sociales y económicos resultantes de las inversiones de capital en objetos lineales de infraestructura vial. En un ejemplo concreto se muestra el procedimiento de evaluación y los cálculos de indicadores económicos resumidos para grupos y para el proyecto en general. Lo que muestra es una posibilidad de aplicación de una técnica bastante difÃcil y su eficiencia como herramienta cientÃfica de evaluación compleja para la solución de tareas aplicadas en la construcción de carreteras. Y el uso de normas de construcción departamentales en combinación con los métodos dinámicos de evaluación basados en el análisis de flujos de efectivo puede aumentar sustancialmente la validez cientÃfica de las decisiones administrativas y la calidad de los proyectos de inversión en el campo del desarrollo de infraestructura vial.A técnica de avaliação de eficiência de investimentos de capital em construção e reconstrução de rodovias é descrita neste artigo. Apesar do grau de prontidão do dispositivo metódico, normas de construção especializadas do VSN 21-83 voltadas para a implementação de tal avaliação não foram amplamente adotadas em vista das dificuldades surgidas no decorrer da coleta de dados básicos, sua confiabilidade e qualidade. O presente artigo contém as caracterÃsticas dos componentes agrupados e critérios de avaliação, em particular, a descrição dos indicadores de liquidação em uma seção dos efeitos intra-transporte, extra-transporte e sociais e econômicos resultantes de investimentos de capital em objetos lineares de infraestrutura rodoviária. Em um exemplo concreto, o procedimento de avaliação e os cálculos de indicadores econômicos resumidos para grupos e para o projeto em geral são mostrados. O que mostra é uma possibilidade de aplicação de técnica bastante difÃcil e sua eficiência como ferramenta cientÃfica de avaliação complexa para a solução de tarefas aplicadas na construção de estradas. E o uso de normas de construção departamental em combinação com os métodos dinâmicos de avaliação com base na análise dos fluxos de caixa pode aumentar substancialmente a validade cientÃfica das decisões administrativas e da qualidade dos projetos de investimento no campo do desenvolvimento da infraestrutura rodoviária
Convex ordering and quantification of quantumness
The characterization of physical systems requires a comprehensive
understanding of quantum effects. One aspect is a proper quantification of the
strength of such quantum phenomena. Here, a general convex ordering of quantum
states will be introduced which is based on the algebraic definition of
classical states. This definition resolves the ambiguity of the quantumness
quantification using topological distance measures. Classical operations on
quantum states will be considered to further generalize the ordering
prescription. Our technique can be used for a natural and unambiguous
quantification of general quantum properties whose classical reference has a
convex structure. We apply this method to typical scenarios in quantum optics
and quantum information theory to study measures which are based on the
fundamental quantum superposition principle.Comment: 9 pages, 2 figures, revised version; published in special issue "150
years of Margarita and Vladimir Man'ko
Age features of O2 mass transfer regimes in adolescents’ body at rest
The results of complex studies of the quantitative relationship between the stage-by-stage mass transfer of O2 and the efficiency of cardiorespiratory system functioning in relation to its consumption in adolescents’ body under conditions of relative rest are presented.
The results obtained show that in adolescents, the modes of mass transfer of O2 in the body and the nature of the respiratory and circulatory systems functioning in relation to its consumption have a number of age-related differences compared with adult men. So, in adolescents, the external respiration system at rest functions less economically than in adults. Each liter of O2 consumed by adolescents is extracted from almost 3 liters more than in adults the amount of air ventilated per minute through the lungs. The volumetric indicators of blood circulation are also higher in adolescents, which may indicate the influence of neuro-humoral rearrangements in the body during the pubertal period. The coefficient of oxygen utilization by tissues from arterial blood in adolescents turned out to be significantly higher, which may characterize a higher tension of tissue metabolic processes
Measuring microwave quantum states: tomogram and moments
Two measurable characteristics of microwave one-mode photon states are
discussed: a rotated quadrature distribution (tomogram) and
normally/antinormally ordered moments of photon creation and annihilation
operators. Extraction of these characteristics from amplified microwave signal
is presented. Relations between the tomogram and the moments are found and can
be used as a cross check of experiments. Formalism of the ordered moments is
developed. The state purity and generalized uncertainty relations are
considered in terms of moments. Unitary and non-unitary time evolution of
moments is obtained in the form of linear differential equations in contrast to
partial differential equations for quasidistributions. Time evolution is
specified for the cases of a harmonic oscillator and a damped harmonic
oscillator, which describe noiseless and decoherence processes, respectively.Comment: 10 pages, 1 figure, to appear in Phys. Rev.
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