43,452 research outputs found
Antiresonance and interaction-induced localization in spin and qubit chains with defects
We study a spin chain with an anisotropic XXZ coupling in an external field.
Such a chain models several proposed types of a quantum computer. The chain
contains a defect with a different on-site energy. The interaction between
excitations is shown to lead to two-excitation states localized next to the
defect. In a resonant situation scattering of excitations on each other might
cause decay of an excitation localized on the defect. We find that destructive
quantum interference suppresses this decay. Numerical results confirm the
analytical predictions.Comment: Updated versio
Initial development of eucalyptus grandis (eucalyptus) in field benefited with biochar in Sinop / MT
A project of a new detector for direct Dark Matter search: MACHe3
MACHe3 (MAtrix of Cells of superfluid He3) is a project of a new detector for
direct Dark Matter (DM) search. A cell of superfluid He3 has been developed and
the idea of using a large number of such cells in a high granularity detector
is proposed.This contribution presents, after a brief description of the
superfluid He3 cell, the simulation of the response of different matrix
configurations allowing to define an optimum design as a function of the number
of cells and the volume of each cell. The exclusion plot and the predicted
interaction cross-section for the neutralino as a photino are presented.Comment: 8 pages, 7 figures, Proceedings of Dark Matter 2000 (Marina Del Rey,
Los Angeles, USA, 02/23/2000-02/25/2000
Nonlinear viscosity and velocity distribution function in a simple longitudinal flow
A compressible flow characterized by a velocity field is
analyzed by means of the Boltzmann equation and the Bhatnagar-Gross-Krook
kinetic model. The sign of the control parameter (the longitudinal deformation
rate ) distinguishes between an expansion () and a condensation ()
phenomenon. The temperature is a decreasing function of time in the former
case, while it is an increasing function in the latter. The non-Newtonian
behavior of the gas is described by a dimensionless nonlinear viscosity
, that depends on the dimensionless longitudinal rate . The
Chapman-Enskog expansion of in powers of is seen to be only
asymptotic (except in the case of Maxwell molecules). The velocity distribution
function is also studied. At any value of , it exhibits an algebraic
high-velocity tail that is responsible for the divergence of velocity moments.
For sufficiently negative , moments of degree four and higher may diverge,
while for positive the divergence occurs in moments of degree equal to or
larger than eight.Comment: 18 pages (Revtex), including 5 figures (eps). Analysis of the heat
flux plus other minor changes added. Revised version accepted for publication
in PR
Competição de linhagens de feijão-caupi de porte ereto e crescimento determinado do tipo Canapu no Vale do São Francisco.
Linhagens de feij„o-caupi de porte ereto e crescimento determinado e do tipoëCanapuí foram avaliadas para diversos caracteres, em v·rios ambientesirrigados e de sequeiro do Vale do S„o Francisco, visando ‡ recomendaÁ„o decultivares. As linhagens tipo ëCanapuí foram avaliadas na densidade deplantio de 100.000 plantas/ha, com espaÁamento de 1 m entre linhas,enquanto as linhagens de porte ereto e crescimento determinado foramavaliadas na densidade de plantio de 200.000 plantas/ha, com espaÁamentode 0,5 m entrelinhas, em regime irrigado, no segundo semestre, e desequeiro, no primeiro semestre, nos anos de 2007, 2008 e 2009. Ascultivares controle foram BRS Maratao„, Canapu e BRS Pujante para os doisexperimentos, os quais foram conduzidos no delineamento de blocos ao acasocom trÍs repetiÁ?es. Nas avaliaÁ?es do segundo semestre, quando ocorremas mais altas temperaturas, os genÛtipos Maratao„ e Canapu apresentaramas menores produtividades, nos dois experimentos. Foi observada diferenÁaestatÌstica significativa (p<0,01) para a interaÁ„o genÛtipo*ambiente, paraos dois experimentos. Duas linhagens tipo ëCanapuí e trÍs de porte ereto ecrescimento determinado, de diferentes cores, foram selecionadas paraavaliaÁ„o em macroparcelas em v·rios ambientes, visando ‡ recomendaÁ„ode cultivares para a regi„o do Vale do S„o Francisco.bitstream/item/17894/1/Boletim-de-Pesquisa.pd
Ação de aminoácidos de peixe na germinação e desenvolvimento de plântulas de melancia.
Suplemento. Edição dos Trabalhos do 50. Congresso Brasileiro de Olericultura, Guarapari, jul. 2010
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