Artículos de revista: Envíos recientes
Mostrando ítems 841-860 de 887
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Siraty, una nueva localidad fosilífera con maderas y estípites de la formación Tacuary (pérmico superior), Paraguay
(Museo Argentino de Ciencias Naturales Bernardino Rivadavia, 2018)Se describen maderas y estípites silicificados provenientes de Siraty, una nueva localidad fosilífera de la Formación Tacuary (Pérmico superior), Paraguay. Se identificó Tuvichapteris solmsi Herbst (Marattiales) y los ... -
New gymnosperm wood fossils, a seed ovule structure, and a new generic affinity to cedroxylon canoasense rau from the permian and triassic jurassic of southern Brazil
(Sociedad Brasileira de Pleontología, 2018)Two new species of gymnosperm wood from the Triassic–Jurassic of Brazil are here described [Lobatoxylon kaokense Kräusel and Chapmanoxylon jamuriense (Maheswari) Pant & Singh], and a new age and generic a nity are proposed ... -
Buckya austroamericana nov. gen. et sp. (Bennettitales) from the upper triassic Laguna Colorada formation (El Tranquilo Group), Santa Cruz province, Argentina
(Universidad Nacional de Tucumán. Instituto Superior de Correlación Geológica, 2016)Siraty, a new fossiliferous locality with woods and stipes of the Tacuary Formation (upper Permian), Paraguay. Silicified fossil woods and arborescent stems from Siraty, a new fossiliferous locality of the Tacuary Formation ... -
Multicenter (FX)n/NH3 halogen bonds (X = Cl, Br and n = 1–5). QTAIM descriptors of the strength of the X…N interaction
(Molecular Diversity Preservation International, 2017)In the present work an in depth deep electronic study of multicenter XBs (FX)n/NH3 (X = Cl, Br and n = 1–5) is conducted. The ways in which X X lateral contacts affect the electrostatic or covalent nature of the X N ... -
Simultaneous occurrence of quadruple lewis acid–base interactions between selenium atoms in selenocarbonyl dimers
(Wiley VCH Verlag, 2017)High-level quantum chemical calculations are performed to investigate C=Se···Se=C interactions. Bounded structures are found with binding energies between @4 and @7 kJmol@1. An energy decomposition analysis shows that ... -
Is σ-hole an electronic exchange channel in YX⋯CO interactions?
(Elsevier Science, 2018)A theoretical study of linear YX⋯CO complexes (in which YX are diatomic interhalogens or hydrogen halide) has been performed to high-level quantum chemical calculations. Calculations show that at the equilibrium geometry, the ... -
Lewis acid-base behavior of hypervalent halogen fluorides in gas phase
(Springer, 2017)Theoretical studies on Lewis acid-base behavior of hypervalent halogen fluorides, F3X and F5X (X = Cl, Br, I) have been instrumental in guiding this work. We have also examined whether the hole-lump concept explains the ... -
A theoretical study of the strong interactions between carbón dioxide and OH+ and NH2+ products resulting from protonation of 1,2-dioxirane-3-one and 1,2-oxaziridine-3-one, respectively
(Springer, 2016)In this work, we investigate the nature of the O– O and O–N interactions in protonated 1,2-dioxirane-3-one derivatives and protonated 1,2-oxaziridine-3-one derivatives, respectively. The quantum theory of atoms in molecules ... -
Naturaleza de las interacciones Mδ+⋯δ+C-Oδ- en carbonilos metálicos : un estudio basado en la topología de la densidad de carga electrónica y su función laplaciana
(Sociedade Brasileira de Química, 2016)nature of the metal–ligand interactions, in the [Ti(CO)6]2-, [V(CO)6]-, [Cr(CO)6], [Mn(CO)6]+, [Fe(CO)6]2+ and [Co(CO)6]3+ complexes has been studied by means of topological analyses of the electron charge density, using ... -
Intermolecular perturbation in the self‑assembly of melamine
(Springer, 2016)A theoretical study has been conducted on a set of supramolecular complexes based on 1,3,5-triazine-2,4,6- triamine, or melamine (M), with cyanuric acid (CA), trithiocyanuric acid (TCA), and two mono-substituted ... -
Halogen bonding. The role of the polarizability of the electron-pair donor
(Royal Society of Chemistry, 2016)The nature of F–Br X–R interactions (with X = F, Cl, Br, I and R = –H, –F) has been investigated through theoretical calculation of molecular potential electrostatic (MEP), molecular polarizability, atoms in molecules ... -
Prodromus sinsistemático de la República Argentina y una breve introducción a los estudios fitosociológicos
(Sociedad Argentina de Botánica, 2016)Se presenta el Prodromus de la vegetación de Argentina, que constituye la primera versión del sinsistema nacional detallado hasta nivel de asociación y subasociación. Se describen las 57 clases de vegetación hasta ahora ... -
What is the enthalpy of formation of pyrazine-2-carboxylic acid?
(Elsevier, 2016)There are two contemporary conflicting, indeed, incompatible determinations of measurements of the enthalpies of combustion and of formation of pyrazine-2-carboxylic acid in the literature, ( 2268.0 ± 0.9 and 271.2 ± ... -
Theoretical characterization of the chemical bonds of some three-membered ring compounds through QTAIM theory
(Springer, 2015)In this paper, we investigate the nature of the carbonyl and the intraring C–C, C–N, C–O, N–N, O–O and N–O bonds of cyclopropanone and the following cyclopropanone derivatives: aziridine-2-one (1); oxirane-2-one (2); ... -
Protonated heterocyclic derivatives of cyclopropane and cyclopropanone : classical species, alternate sites, and ring fragmentation
(Canadian Science Publishing, 2015)A computational study has been performed for protonated oxygen- or nitrogen-containing heterocyclic derivatives of cyclopropane and cyclopropanone. We have searched for the most stable conformations of the protonated ... -
Double hole lump interaction between halogen atoms
(American Chemical Society, 2015-03-31)In this paper a theoretical study has been carried out to investigate the nature of the unusual halogen− halogen contacts in the complexes R−X···X−R (with R = −H, −Cl, −F and X = Cl, Br, I). AIM, NBO, and MEP analyses have ... -
Composición de mamíferos medianos y grandes de la reserva natural provincial Rincón de Santa María (Corrientes, Argentina) : comparación con su zona de amortiguamiento y estado de conservación
(Sociedad Argentina para el Estudio de los Mamíferos, 2015)El presente trabajo tuvo como objetivo realizar una evaluación y comparación de mamíferos medianos y grandes de la reserva Rincón de Santa María y su zona de amortiguamiento. Los registros se realizaron mediante avistamientos ... -
Desarrollo y calibración de dispositivos fotovoltaicos para determinar el Recurso solar utilizable por SFCR.
(Asociación Argentina de Energías Renovables y Medio Ambiente, 2014-09)Para proporcionar una evaluación precisa de la capacidad de generación de dispositivos fotovoltaicos es necesario determinar de forma adecuada el recurso solar disponible. Diferentes autores afirman que celdas FV de ... -
Equipamiento multiproposito para el espacio público: cargador solar para dispositivos móviles
(Asociación Argentina de Energías Renovables y Medio Ambiente, 2016)El objetivo del presente artículo es exponer los resultados del desarrollo tecnológico denominado “Cargador Solar para dispositivos móviles” y su transferencia tecnológica en un ambiente urbano en la Región Nordeste de la ... -
Atlantic forest replacement by non native tree plantations : comparing aboveground necromass between native forest and pine plantation ecosystems
(Elsevier, 2016)Necromass is a critical structural and functional component of forest ecosystems that represents an important and relatively long-lived aboveground forest carbon pool. In the Atlantic Forest of Northern Argentina, a large ...
