8,800 research outputs found

    An exact master equation for the system-reservoir dynamics under the strong coupling regime and non-Markovian dynamics

    Get PDF
    In this paper we present a method to derive an exact master equation for a bosonic system coupled to a set of other bosonic systems, which plays the role of the reservoir, under the strong coupling regime, i.e., without resorting to either the rotating-wave or secular approximations. Working with phase-space distribution functions, we verify that the dynamics are separated in the evolution of its center, which follows classical mechanics, and its shape, which becomes distorted. This is the generalization of a result by Glauber, who stated that coherent states remain coherent under certain circumstances, specifically when the rotating-wave approximation and a zero-temperature reservoir are used. We show that the counter-rotating terms generate fluctuations that distort the vacuum state, much the same as thermal fluctuations.Finally, we discuss conditions for non-Markovian dynamics

    Comment on "Spin-1 aggregation model in one dimension"

    Full text link
    M. Girardi and W. Figueiredo have proposed a simple model of aggregation in one dimension to mimic the self-assembly of amphiphiles in aqueous solution [Phys. Rev. E 62, 8344 (2000)]. We point out that interesting results can be obtained if a different set of interactions is considered, instead of their choice (the s=1 Ising model).Comment: Accepted for publication in Phys. Rev.

    Electronic properties of curved graphene sheets

    Full text link
    A model is proposed to study the electronic structure of slightly curved graphene sheets with an arbitrary number of pentagon-heptagon pairs and Stone-Wales defects based on a cosmological analogy. The disorder induced by curvature produces characteristic patterns in the local density of states that can be observed in scanning tunnel and transmission electron microscopy.Comment: Corrected versio

    Ornithological bibliography of the Azores

    Get PDF
    Only scientific publications up to 1980 are included in this bibliography. Other old narrations containing information on Azorean ornithology are being assembled for future publication. Certain unpublished works will also be dealt with. The part for consultation has been arranged in three sections. The first presents a numbered list of papers and books in chronological order up to 1980. Last minute alterations obliged us to eliminate some items and to use «bis» for repeated numbers in some cases. The second section consists of the list of papers under their authors in alphabetical order. Finally, the third section consists of an index of the scientific names of the species cited. The index contains three types of entries: - The names of the genera, in capital letters, followed by the specific and subspecific names, which lead to their numbers in the chronological list. The latter are accompanied by the relevant page numbers, in brackets. - The names of the species, in small letters in bold-faced type, lead to the names of the genera. - The names of the subspecies, in normal small letters, lead to the genera and species. Example: Fringilla coelebs moreletti entered under FRINGILLA, coelebs and moreletti, with the bibliographical references only under the complete name. Papers of Nºs. 17, 41, 72, 74, 76 have not been consulted by us; all other works are available in our library

    Phytoseiid mites of Colombia (Acarina: Phytoseiidae).

    Get PDF
    This is the second report of the phytoseiids of Colombia. A new genus and species, Quadromalus colombiensis and Euseius ricinus n.sp. are described, bringing the total to 17 species of phytoseiids for Colombia

    Aflatoxina M1 em leite: um risco para a saúde pública.

    Get PDF
    Introdução. As Aflatoxinas. A Aflatoxina M1 (AFM1). Mecanismos de contaminação do leite por AFM1. Principais efeitos tóxicos. Relação de AFB1 ingerida e a concentração de AFM1, excretada no leite. Prevenção. Métodos de detecção e qualificação de Aflatoxina M1 em leite e derivados. Legislação. Referências bibliográficas.bitstream/item/79983/1/doc67-2005.pd
    corecore