Search results for " Combination"
showing 10 items of 923 documents
Comparative Theoretical Analysis of BN Nanotubes Doped with Al, P, Ga, As, In, and Sb
2013
SUMMARY AND CONCLUDING REMARKS We have performed large-scale first-principles calculations ofthe electronic structure of (5,5) boron nitride nanotubescontaining the following substitutional impurity atoms: Al, P,Ga, As, In, and Sb. Calculations have been performed using thetwo methods: (i) linear combination of atomic orbitals(LCAO) with the atomic-centered Gaussian-type functions asa basis set and (ii) linearized augmented cylindrical wave(LACW) accompanied with the local density functional andmuffin-tin approximations for the electronic potential. In arelatively good qualitative agreement, both methods predict lowformation energies and, thus, relative stability of point defectsthat are assoc…
Ab initio calculations of structural, electronic and vibrational properties of BaTiO3 and SrTiO3 perovskite crystals with oxygen vacancies
2020
The first-principles (ab initio) computations of the structural, electronic, and phonon properties have been performed for cubic and low-temperature tetragonal phases of BaTiO3 and SrTiO3 perovskite crystals, both stoichiometric and non-stoichiometric (with neutral oxygen vacancies). Calculations were performed with the CRYSTAL17 computer code within the linear combination of atomic orbitals approximation, using the B1WC advanced hybrid exchange-correlation functional of the density-functional-theory (DFT) and the periodic supercell approach. Various possible spin states of the defective systems were considered by means of unrestricted (open shell) DFT calculations. It was demonstrated that…
Multi-scale multireference configuration interaction calculations for large systems using localized orbitals: Partition in zones
2012
A new multireference configuration interaction method using localised orbitals is proposed, in which a molecular system is divided into regions of unequal importance. The advantage of dealing with local orbitals, i.e., the possibility to neglect long range interaction is enhanced. Indeed, while in the zone of the molecule where the important phenomena occur, the interaction cut off may be as small as necessary to get relevant results, in the most part of the system it can be taken rather large, so that results of good quality may be obtained at a lower cost. The method is tested on several systems. In one of them, the definition of the various regions is not based on topological considerati…
Systematic Position of Gastropini (Diptera: Ephydridae), and a Review of Two Included Genera:GastropsWilliston andNotacanthinaMacquart
2017
The placement of the tribe Gastropini within the subfamily Gymnomyzinae, with the tribe Gymnomyzini as a sister-group, is supported. Validity for two genera Gastrops Williston and Notacanthina Macquart (senior synonym of Beckeriella Williston) is maintained. Particular characters of their proboscis, ventral receptacle and the male terminalia are presented. A key to species and habitus photographs of selected species of Gastrops and Notacanthina are provided. The following new combinations are proposed: Notacanthina clypeata (Lizarralde de Grosso, 1986), comb. nov., N. fasciata (Mathis & Grimaldi, 2000), comb. nov., N. filipina (Lizarralde de Grosso, 1994), comb. nov., N. gigas (Lizarralde d…
Taxonomic review of the plant bug genera Amapacylapus and Cylapus with descriptions of two new species and a key to the genera of Cylapini (Hemiptera…
2017
The plant bug tribe Cylapini (Hemiptera: Heteroptera: Miridae: Cylapinae) is diagnosed and a worldwide key to the genera of the tribe is provided. The taxonomic review of the New World Cylapini genera Amapacylapus Carvalho & Fontes,1968 and Cylapus Say, 1832 is provided, including a key to species, diagnoses and redescriptions of genera and most included species, and descriptions of two new species, Amapacylapus unicolor sp. nov. (Ecuador) and Cylapus luridus sp. nov. (Brazil). Illustrations of the male genitalia, color photographs of the adult and scanning electron micrographs of the selected species are provided. The genus Cylapocerus Carvalho & Fontes, 1968 syn. nov. is proposed …
Pigmentation polymorphism in the invasive amphipod Dikerogammarus villosus : some insights into its maintenance
2004
Dikerogammarus villosus, a freshwater invasive amphipod, exhibits conspicuous pigmentation polymorphism. This polymorphism is documented in two recently colonized areas, the Saand Moselle rivers (north-eastern France), and some of the mechanisms by which pigmentation polymorphism can arise and be maintained are addressed. Body size, reproductive status, fecundity and mate choice are compared among morphs of D. villosus in field samples collected in summer 2001. Body size and female gonad developmental stage were comparable among the different morphs, suggesting that polymorphism is not the result of changes in pigmentation with age or moult- cycle. Fecundity and reproductive status (paired …
Notulae to the Italian alien vascular flora: 9
2020
In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Furthermore, three new combinations are proposed. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.
Notulae to the Italian native vascular flora: 4
2017
In this contribution new data concerning the distribution of native vascular flora in Italy are presented. It includes new records, exclusion, extinction and confirmations to the Italian administrative regions for taxa in the generaAndrosace,Artemisia,Fragaria,Melampyrum,Myosotis,Petrorhagia,Phillyrea,Rosa,Rumex,Spiranthes,Trifolium, andVicia. Furthermore, a new combination in the genusOmalothecais proposed.
Notulae to the Italian alien vascular flora: 3
2017
In this contribution, new data concerning the Italian distribution of alien vascular flora are presented. It includes new records, exclusions, confirmations, and status changes for Italy or for Italian administrative regions for taxa in the genera Acer, Amaranthus, Araujia, Aubrieta, Avena, Bidens, Calycanthus, Celtis, Elaeagnus, Eragrostis, Euonymus, Fallopia, Ficus, Hedera, Lantana, Ligustrum, Ludwigia, Morus, Oenothera, Opuntia, Oxalis, Parkinsonia, Paspalum, Paulownia, Platycladus, Pleuropterus, Rumex, Salvia, Senecio, Setaria, Syagrus, Tradescantia, Trifolium and Yucca. Furthermore, a new combination in the genus Vicia is proposed.
Notulae to the Italian alien vascular flora: 4
2017
In this contribution, new data concerning the Italian distribution of alien vascular flora are presented. It includes new records and exclusions for Italy or for Italian administrative regions of taxa in the genera Cedrus, Cenchrus, Citrus, Cyrtomium, Diospyros, Elaeagnus, Erigeron, Iris, Oenothera, Pavonia, Phytolacca, Styphnolobium, and Verbena. Furthermore, a new combination in the genus Amaranthus is proposed.