53 research outputs found
Anura, Hylidae, <i>Dendropsophus nahdereri</i> (Lutz and Bokermann, 1963): Distribution extension and new state record.
Dendropsophus nahdereri is included in the Dendropsophus marmoratus group. Its distribution is known fromthe Brazilian states of Paraná and Santa Catarina. Here we report new records of this species and briefly describe the habitatof calling males. We found new localities of occurrence of D. nahdereri in Brazilian states of Santa Catarina and Rio Grandedo Sul. We collected calling males in temporary lentic water bodies surrounded by arboreal vegetation, inside and on theborder of native forest, and inside Pinus plantations near native forest
Mechanisms of photo double ionization of helium by 530 eV photons
We have measured fully differential cross sections for photo double ionization of helium 450eV above the threshold. We have found an extremely asymmetric energy sharing between the photoelectrons and an angular asymmetry parameter β≃2 and β≃0 for the fast and slow electrons, respectively. The electron angular distributions show a dominance of the shakeoff for 2eV electrons and clear evidence of an inelastic electron-electron scattering at an electron energy of 30eV. The data are in excellent agreement with convergent close-coupling calculations
Transferência de tecnologia em práticas promotoras de rendimento de grãos de milho em instituições de ensino agrotécnico do Rio Grande do Sul e Santa catarina, safra 2004/2005.
bitstream/CNPT-2010/40665/1/p-do47.pd
Interatomic Coulombic decay following the Auger decay: Experimental evidence in rare-gas dimers
Interatomic Coulombic decay (ICD) in Ar(2), ArKr and Kr(2) following Ar 2p or Kr 3d Auger decay has been investigated by means of momentum-resolved electron-ion-ion coincidence spectroscopy. This sequential decay leads to Coulombic dissociation into dication and monocation. Simultaneously determining the kinetic energy of the ICD electron and the kinetic energy release between the two atomic ions, we have been able to unambiguously identify the ICD channels. We find that, in general, spin-conserved ICD, in which the singlet (triplet) dicationic state produced via the atomic Auger decay preferentially decays to the singlet (triplet) state, transferring the energy to the other atom, is faster than spin-flip ICD, in which the Auger final singlet (triplet) dicationic state decays to the triplet (singlet) state. However, spin-flip ICD may take place when spin-conserved ICD becomes energetically forbidden. Dipole-forbidden ICDs from Kr(2+)(4s(-2) (1)S)-B (B = Ar or Kr) to Kr(2+)(4p(-2) (1)D, (3)P)-B(+) are also observed. (c) 2008 Elsevier B.V. All rights reserved
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Fragmentation pathwaysfor selected electronic states of theacetylene dication
Coincident measurement of the Auger electron and fragmention momenta emitted after carbon core-level photoionization of acetylenehas yielded new understanding of how the dication fragments. Ab initiocalculations and experimental data, including body-frame Auger angulardistributions, are used to identify the parent electronic states andtogether yield a comprehensive map of the dissociation pathways whichinclude surface crossings and barriers to direct dissociation. The Augerangular distributions show evidence of core-holelocalization
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