16,570 research outputs found
Seed bank and control of Rottboellia exaltata using clomazone alone and in combination with other herbicides.
Objetivou-se, com este trabalho, estudar o banco de sementes e o controle de Rottboellia exaltata L.f. com clomazone, isolado e em associação com outros herbicidas, em áreas de cana-soca com baixa e alta infestação.bitstream/item/131076/1/4466-18529-1-PB-Nubia.pdfOn line
Generalized Hermite-Gauss decomposition of the two-photon state produced by spontaneous parametric down-conversion
We provide a general decomposition of the two-photon state produced by
spontaneous parametric down-conversion in Hermite-Gaussian modes, in the case
that the pump beam is described by a Hermite-Gaussian beam of any order. We
show that the spatial correlations depend explicitly on the order of the pump
beam, as well as other experimental parameters. We use the decomposition to
demonstrate a few interesting cases. Our results are applicable to the
engineering of two-photon spatial entanglement, in particular for non-Gaussian
states.Comment: 14 page draft, 5 figure
Performance measurement and management in portuguese law enforcement
Performance measurement of police services is complicated by ambiguous and
complex goal- and objectives-setting, and by the difficulties of measuring outputs.
This article looks at the organizational and management changes being made in
Portuguese police forces. The authors fill a gap in the literature on performance
measurement in Portugal by taking a national approach to the study of how law
enforcement agencies are introducing new management accounting changes. The
article therefore widens the debate on performance measurement and performance
improvements in law enforcement
Vertex Operators and Soliton Solutions of Affine Toda Model with U(2) Symmetry
The symmetry structure of non-abelian affine Toda model based on the coset
is studied. It is shown that the model possess
non-abelian Noether symmetry closing into a q-deformed
algebra. Specific two vertex soliton solutions are constructed.Comment: 17 pages, latex, misprints corrected, version to appear in J.Phys
Strings from position-dependent noncommutativity
We introduce a new set of noncommutative space-time commutation relations in
two space dimensions. The space-space commutation relations are deformations of
the standard flat noncommutative space-time relations taken here to have
position dependent structure constants. Some of the new variables are
non-Hermitian in the most natural choice. We construct their Hermitian
counterparts by means of a Dyson map, which also serves to introduce a new
metric operator. We propose PTlike symmetries, i.e.antilinear involutory maps,
respected by these deformations. We compute minimal lengths and momenta arising
in this space from generalized versions of Heisenberg's uncertainty relations
and find that any object in this two dimensional space is string like,
i.e.having a fundamental length in one direction beyond which a resolution is
impossible. Subsequently we formulate and partly solve some simple models in
these new variables, the free particle, its PT-symmetric deformations and the
harmonic oscillator.Comment: 11 pages, Late
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