RESUMO
This work reports a theoretical investigation on the elastic-positron collision with the 1,1-difluoroethylene molecule for energies up to 10 eV. We have employed the Schwinger multichannel method in the static-plus polarization level of approximation to obtain the integral and differential cross sections. In order to account for the long-range potential due to the permanent dipole moment of the target, the Born-closure procedure has been employed. Also, our present differential cross sections have been applied to estimate a correction to the total cross section measurements available in the literature.
RESUMO
BACKGROUND: This article provides a quantitative description of flora specimens stored in the Jardim Botânico of Rio de Janeiro Herbarium that belongs to the Federal Conservation Units of Caatinga's phytogeography domain. The Caatinga represents 11% of Brazilian territory and is, in South America, the largest and most biodiverse semi-arid tropical ecoregion, yet only 5% of its territory is covered by Federal Conservation Units, with few collections of flora samples. Thus, providing a georeferenced inventory of existing collections is essential for purposes of species distribution, environmental management and conservation. The aim of this data paper is to gauge, by means of geographic coordinates correction and retrieval of the flora specimens present in the RB Herbarium, the amount of specimen gatherings performed in the Federal Conservation Units belonging to the Caatinga domain. NEW INFORMATION: Currently, the RB data is publicly available online at several biodiversity portals, such as our institutional database JABOT, the Reflora Virtual Herbarium, the SiBBr and the GBIF portal (Lanna et al. 2019). However, a description of the dataset that belongs to the Federal Conservation Units of Caatinga's phytogeography domain as a whole is not yet available in the literature.
