758 research outputs found
An exact master equation for the system-reservoir dynamics under the strong coupling regime and non-Markovian dynamics
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
Ornithological bibliography of the Azores
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 Certain unpublished works will also be dealt with.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
Heterogeneidade da relação entre produtividade da soja e severidade da ferrugem asiática: uma análise exploratória.
This work aimed to conduct an exploratory, prior to meta-analysis, assessment of the heterogeneity of the linear relationship between soybean yield (Y) and the severity (X) of a foliar fungal disease (soybean rust) from 144 fungicide trials conducted in five years and 45 locations in Brazil. We used graphical analysis to explore the within- and between-trial variability of model parameter estimates (effect sizes) and summary measures for model goodness-of-fit and influence analysis. In the estimation of the weighted mean regression coefficients, following the metaanalysis concept, we propose a method that takes into account the magnitude of influence measures as well as the uncertainties of parameters estimates, usually the inverse of the standard error of for the parameter estimate. High between-trial heterogeneity was observed for parameter estimates, standard errors (within trial variability), determination coefficient and influence measures. Graphical analysis suggested influence of timing of disease onset and control yield class on model slope, which will be quantified further using a meta-analytical approach
Hypersonic jets in astrophysical conditions: focus on spreading and asymmetric stability properties
High Mach number jets emanating from young stars show remarkable collimation,
low opening angle and resilience against the growth of instabilities,
especially the asymmetric ones. In recent laboratory experiments instances of
asymmetric three-dimensional low amplitude long waves aligned with the jet
axis were observed Belan et al (2013 Astron. Astrophys. 554 A99). To explore
the collimation, spreading, and asymmetric stability properties of hypersonic jets
we carried out laboratory experiments and numerical simulations in two and
three spatial dimensions. We find that laboratory hydrodynamic jets with high
Mach numbers remain collimated, for hundreds of jet radii in length and
maintain low opening angles. These findings are confirmed by 3D numerical
simulations carried out after time-dependent, asymmetric perturbations are
applied at the jet inlet. Both experimental and perturbed simulated jets show
non-axial modes with long wavelengths, whose growth does not disrupt the jet
in the domain considered
Métodos probabilÃsticos para quantificar a influência do El Niño/oscilação sul sobre o risco de epidemias.
Neste trabalho, apresentamos e discutimos as vantagens e limitações de métodos estatÃsticos paramétricos e semi-paramétricos para a caracterização da influência do fenômeno El Nino/Oscilação Sul (ENOS) sobre o risco de epidemias de doenças de plantas. Foram utilizados dados simulados de um Ãndice de severidade da ferrugem asiática em soja para Rosário do Sul, RS, local previamente identificado como passÃvel da influência de ENOS na precipitação pluvial no perÃodo da safra. A influência ENOS sobre a produtividade agrÃcola e outras variáveis dependentes da precipitação pluviométrica, como a severidade de doenças, é bem conhecida e documentada em todo o mundo. No entanto, o uso rigoroso de abordagens probabilÃsticas inferenciais para quantificação da influência de indicadores climáticos sobre o de risco de epidemias ainda é raro
Electromagnetically induced transparency and dynamic Stark effect in coupled quantum resonators
In this work we reproduce the phenomenology of the electromagnetically
induced transparency and dynamic Stark effect in a dissipative system composed
by two coupled bosonic fields under linear and nonlinear amplification process.
Such a system can be used as a quantum switch in networks of oscillators
Hypersonic jets in astrophysical conditions: focus on spreading and asymmetric stability properties
High Mach number jets emanating from young stars show remarkable collimation,
low opening angle and resilience against the growth of instabilities,
especially the asymmetric ones. In recent laboratory experiments instances of
asymmetric three-dimensional low amplitude long waves aligned with the jet
axis were observed Belan et al (2013 Astron. Astrophys. 554 A99). To explore
the collimation, spreading, and asymmetric stability properties of hypersonic jets
we carried out laboratory experiments and numerical simulations in two and
three spatial dimensions. We find that laboratory hydrodynamic jets with high
Mach numbers remain collimated, for hundreds of jet radii in length and
maintain low opening angles. These findings are confirmed by 3D numerical
simulations carried out after time-dependent, asymmetric perturbations are
applied at the jet inlet. Both experimental and perturbed simulated jets show
non-axial modes with long wavelengths, whose growth does not disrupt the jet
in the domain considered
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