2,885 research outputs found
Hyperfine Quenching of the Level in Zn-like Ions
In this paper, we used the multiconfiguration Dirac-Fock method to compute
with high precision the influence of the hyperfine interaction on the
level lifetime in Zn-like ions for stable and some
quasi-stable isotopes of nonzero nuclear spin between Z=30 and Z=92. The
influence of this interaction on the separation energy is also calculated for the same ions
New expression for the K-shell ionization
A new expression for the total K-shell ionization cross section by electron
impact based on the relativistic extension of the binary encounter Bethe (RBEB)
model, valid from ionization threshold up to relativistic energies, is
proposed. The new MRBEB expression is used to calculate the K-shell ionization
cross sections by electron impact for the selenium atom. Comparison with all,
to our knowledge, available experimental data shows good agreement
Analysis of X-ray spectra emitted from laser-produced plasmas of uranium
In this paper, we used the multiconfiguration Dirac-Fock method to generate
theoretical X-ray spectra for Co-, Ni-, Cu-, Zn-, Ga-, Ge-, As-, Se-, Br-, Kr-,
and Rb-like uranium ions. Using the distribution of these ions in a
laser-produced plasma, for different plasma temperatures, we generate
theoretical spectra, which are compared to experimental data
The contribution of off-shell gluons to the structure functions F_2^c and F_L^c$ and the unintegrated gluon distributions
We calculate the perturbative parts of the structure functions and
for a gluon target having nonzero transverse momentum squared at order
. The results of the double convolution (with respect to the Bjorken
variable and the transverse momentum) of the perturbative part and the
unintegrated gluon densities are compared with HERA experimental data for
. The contribution from structure function ranges (10-30)% of
that of at the kinematical range of HERA experiments.Comment: 34 pages, 8 figure
K X-Ray Energies and Transition Probabilities for He-, Li- and Be-like Praseodymium ions
Theoretical transition energies and probabilities for He-, Li- and Be-like
Praseodymium ions are calculated in the framework of the multi-configuration
Dirac-Fock method (MCDF), including QED corrections. These calculated values
are compared to recent experimental data obtained in the Livermore SuperEBIT
electron beam ion trap facility
Relativistic correlation correction to the binding energies of the ground configuration of Beryllium-like, Neon-like, Magnesium-like and Argon-like ions
Total electronic correlation correction to the binding energies of the
isoelectronic series of Beryllium, Neon, Magnesium and Argon, are calculated in
the framework of relativistic multiconfiguration Dirac-Fock method. Convergence
of the correlation energies is studied as the active set of orbitals is
increased. The Breit interaction is treated fully self-consistently. The final
results can be used in the accurately determination of atomic masses from
highly charged ions data obtained in Penning-trap experiments.Comment: version soumise 3/08/200
REMOTELY SENSED IMAGE FAST CLASSIFICATION AND SMART THEMATIC MAP PRODUCTION
Abstract. Apps available for Smartphone, as well as software for GNSS/GIS devices, permit to easily mapping the localization and shape of an area by acquiring the vertices coordinates of its contour. This option is useful for remote sensing classification, supporting the detection of representative sample sites of a known cover type to use for algorithm training or to test classification results. This article aims to analyse the possibility to produce smart maps from remotely sensed image classification in rapid way: the attention is focalized on different methods that are compared to identify fast and accurate procedure for producing up-to-date and reliable maps. Landsat 8 OLI multispectral images of northern Sicily (Italy) are submitted to various classification algorithms to distinguish water, bare soil and vegetation. The resulting map is useful for many purposes: appropriately inserted in a larger database aimed at representing the situation in a space-time evolutionary scenario, it is suitable whenever you want to capture the variation induced in a scene, e.g. burnt areas identification, vegetated areas definition for tourist-recreational purposes, etc. Particularly, pixel-based classification approaches are preferred, and experiments are carried out using unsupervised (k-means), vegetation index (NDVI, Normalized Difference Vegetation Index), supervised (minimum distance, maximum likelihood) methods. Using test sites, confusion matrix is built for each method, and quality indices are calculated to compare the results. Experiments demonstrate that NDVI submitted to k-means algorithm allows the best performance for distinguishing not only vegetation areas but also water bodies and bare soils. The resulting thematic map is converted for web publishing
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