1,430 research outputs found
Besouro do colorado Leptinotarsa decimlineata: artropodes de importancia quarentenaria.
Identidade; Distribuicao geografica; Hospedeiros; Identificacao; Controle; Riscos fitossanitarios.bitstream/item/107303/1/Besouro-do-colorado.pd
Work and Quantum Phase Transitions: Is there Quantum Latency?
We study the physics of quantum phase transitions from the perspective of
non-equilibrium thermodynamics. For first order quantum phase transitions, we
find that the average work done per quench in crossing the critical point is
discontinuous. This leads us to introduce the quantum latent work in analogy
with the classical latent heat of first order classical phase transitions. For
second order quantum phase transitions the irreversible work is closely related
to the fidelity susceptibility for weak sudden quenches of the system
Hamiltonian. We demonstrate our ideas with numerical simulations of first,
second, and infinite order phase transitions in various spin chain models.Comment: accepted in PR
A survey of UV-excess AGNs in the South Galactic Pole
Spectra, position, magnitudes and colors are presented for 485 faint (B<20.5)
emission line objects selected with the ultraviolet-excess (UVX) criterion on a
area of 24.6 sq. deg in the South Galactic Pole. The objects were selected from
the analysis of pixel-to-pixel stacking of COSMOS scans of UKST U, J and R
plates. The candidates were observed with the Meudon-ESO Fiber Optics System
(MEFOS) at the ESO 3.6m telescope. 429 type 1 AGNs have been identified (373 in
the redshift range 0.3<z<2.2). This sample has allowed the measure of a
difference on the QSO clustering evolution in comparison with that found for
galaxies (La Franca et al 1998). The region is part of the ESO Imaging Survey
(EIS) and of the 2dF QSO redshift survey.Comment: 32 pages, 19 figures. To appear on A&AS, revised after minor comment
Organised turbulence over mobile and immobile hydraulically rough boundaries
33rd IAHR Congress: Water Engineering for a Sustainable EnvironmentThe present work is aimed at the study of near-bed organised turbulence over mobile
and immobile, porous, hydraulically rough boundaries. The bed was permeable and
composed of non-cohesive sediments. Two data sets were analysed, characterised by
the same u*. The mobile bed data featured generalised sediment transport for all size
fractions smaller than the d90. The fixed bed was obtained as result of an armouring
process. Comparison of these data sets reveals differences on such parameters of the
bursting cycle as the maximum shear stress and the transported momentum. These results point to a reorganization of turbulence, in the near-bed region, when the bed is mobile. The impacts of these reorganization are discussed, namely in what concerns the third order moments of the distributions of the velocity fluctuations
Organização e representação do conhecimento agropecuário: alinhando o PLN e a cognição humana em itinerários metodológicos semiautomatizados.
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