1,561 research outputs found
Produção de mudas de espécies lenhosas.
Planejamento das instalações para produção de mudas; Técnicas de produção de mudas.bitstream/CNPF-2009-09/43217/1/doc130.pd
Sazonalidade na produtividade e sobrevivência de minicepas de Eucalyptus benthamii x Eucalyptus dunnii.
Resumo
Coherent States for the Non-Linear Harmonic Oscillator
Wave packets for the Quantum Non-Linear Oscillator are considered in the
Generalized Coherent State framerwork. To first order in the non-linearity
parameter the Coherent State behaves very similarly to its classical
counterpart. The position expectation value oscillates in a simple harmonic
manner. The energy-momentum uncertainty relation is time independent as in a
harmonic oscillator. Various features, (such as the Squeezed State nature), of
the Coherent State have been discussed
Automated search for galactic star clusters in large multiband surveys: I. Discovery of 15 new open clusters in the Galactic anticenter region
Aims: According to some estimations, there are as many as 100000 open
clusters in the Galaxy, but less than 2000 of them have been discovered,
measured, and cataloged. We plan to undertake data mining of multiwavelength
surveys to find new star clusters. Methods: We have developed a new method to
search automatically for star clusters in very large stellar catalogs, which is
based on convolution with density functions. We have applied this method to a
subset of the Two Micron All Sky Survey catalog toward the Galactic anticenter.
We also developed a method to verify whether detected stellar groups are real
star clusters, which tests whether the stars that form the spatial density peak
also fall onto a single isochrone in the color-magnitude diagram. By fitting an
isochrone to the data, we estimate at the same time the main physical
parameters of a cluster: age, distance, color excess. Results: For the present
paper, we carried out a detailed analysis of 88 overdensity peaks detected in a
field of degrees near the Galactic anticenter. From this analysis,
15 overdensities were confirmed to be new open clusters and the physical and
structural parameters were determined for 12 of them; 10 of them were
previously suspected to be open clusters by Kronberger (2006) and Froebrich
(2007). The properties were also determined for 13 yet-unstudied known open
clusters, thus almost tripling the sample of open clusters with studied
parameters in the anticenter. The parameters determined with this method showed
a good agreement with published data for a set of well-known clusters.Comment: accepted to A&
Quadratic Effective Action for QED in D=2,3 Dimensions
We calculate the effective action for Quantum Electrodynamics (QED) in D=2,3
dimensions at the quadratic approximation in the gauge fields. We analyse the
analytic structure of the corresponding nonlocal boson propagators
nonperturbatively in k/m. In two dimensions for any nonzero fermion mass, we
end up with one massless pole for the gauge boson . We also calculate in D=2
the effective potential between two static charges separated by a distance L
and find it to be a linearly increasing function of L in agreement with the
bosonized theory (massive Sine-Gordon model). In three dimensions we find
nonperturbatively in k/m one massive pole in the effective bosonic action
leading to screening. Fitting the numerical results we derive a simple
expression for the functional dependence of the boson mass upon the
dimensionless parameter e^{2}/m .Comment: 10 pages, 2 figure
Produção de mudas de corticeira-do-mato por miniestaquia a partir de propágulos juvenis.
bitstream/CNPF-2009-09/43377/1/com_tec130.pd
Position-dependent-mass; Cylindrical coordinates, separability, exact solvability, and PT-symmetry
The kinetic energy operator with position-dependent-mass in cylindrical
coordinates is obtained. The separability of the corresponding Schr\"odinger
equation is discussed within radial cylindrical mass settings. Azimuthal
symmetry is assumed and spectral signatures of various z-dependent interaction
potentials (Hermitian and non-Hermitian PT-symmetric) are reported.Comment: 16 page
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