Renormalization of spin excitations and Kondo effect in open-shell nanographenes

We study spin excitations and the Kondo effect in open-shell nanographenes, motivated by recent scanning tunneling inelastic spectroscopy experiments. Specifically, we consider three systems: the triangulene, the extended triangulene with rocket shape, both with an S = 1 ground state, and a triangulene dimer with S = 0 on account of intermolecular exchange. We focus on the consequences of hybridization of the nanographene zero modes with a conducting substrate on the dI/dV line shapes associated with spin excitations. The partially filled nanographene zero modes coupled to the conduction electrons in the substrate constitute multiorbital Anderson impurity models that we solve in the one-crossing approximation, which treats the coupling to the substrate to infinite order. We find that the coupling to the substrate leads to (i) renormalization of the spin flip excitation energies of the bare molecule, (ii) broadening of the spectral features, and (iii) the emergence of zero bias Kondo peaks for the S = 1 ground states. The calculated substrate induced shift of the spin excitation energies is found to be significantly larger than their broadening, which implies that this effect has to be considered when comparing experimental results and theory.D.J. acknowledges funding by the Basque Government through grant “Grupos Consolidados UPV/EHU del Gobierno Vasco” (Grant No. IT1249-19). R.O. acknowledges financial support from Generalitat Valenciana and Fondo Social Europeo (Grant No. ACIF/2018/175). J.F.R. acknowledges financial support from Generalitat Valenciana (Prometeo2017/139), and MINECO-Spain (Grant No. PID2019-109539GB-C41). J.F.R. and D.J. acknowledge funding from FEDER/Junta de Andalucía-Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Grant No. P18-FR-4834

Theory of triangulene two-dimensional crystals

Equilateral triangle-shaped graphene nanoislands with a lateral dimension of n benzene rings are known as [n]triangulenes. Individual [n]triangulenes are open-shell molecules, with single-particle electronic spectra that host n−1 half-filled zero modes and a many-body ground state with spin S = (n−1)/2. The on-surface synthesis of triangulenes has been demonstrated for n = 3, 4, 5, 7 and the observation of a Haldane symmetry-protected topological phase has been reported in chains of [3]triangulenes. Here, we provide a unified theory for the electronic properties of a family of two-dimensional honeycomb lattices whose unit cell contains a pair of triangulenes with dimensions na, nb. Combining density functional theory and tight-binding calculations, we find a wealth of half-filled narrow bands, including a graphene-like spectrum (for na = nb = 2), spin-1 Dirac electrons (for na = 2, nb = 3), px,y-orbital physics (for na = nb = 3), as well as a gapped system with flat valence and conduction bands (for na = nb = 4). All these results are rationalized with a class of effective Hamiltonians acting on the subspace of the zero-energy states that generalize the graphene honeycomb model to the case of fermions with an internal pseudospin degree of freedom with C3 symmetry.We acknowledge financial support from the Ministry of Science and Innovation of Spain (Grant No. PID2019-109539GB-41), from Generalitat Valenciana (Grants Nos. Prometeo2021/017 and MFA/2022/045), from Fundação para a Ciência e a Tecnologia, Portugal (Grant No. PTDC/FIS-MAC/2045/2021), from SNF Sinergia (Grant Pimag) and from FEDER/Junta de Andalucía-Consejería de Transformación Económica, Industria, Conocimiento y Universidades (Grant No. P18-FR-4834). R Ortiz acknowledges funding from Generalitat Valenciana and Fondo Social Europeo (Grant No. ACIF/2018/175) and Ministry of Science and Innovation of Spain (PID2020-115406GB-I00). G Catarina acknowledges financial support from Fundação para a Ciência e a Tecnologia (Grant No. SFRH/BD/138806/2018)

The Algarve climatophilous vegetation series – Portugal: a base document to the planning, management and nature conservation Les séries de végètation climatophiles de l’Algarve - Portugal: un document de base pour la planification, gestion et conservation de la nature

This work was developed as part of PhD research devoted to the flora and vegetation of the Caldeirão and Monchique mountains that aims to identify the vegetation climatophilous series and use them as an environmental diagnosis of Algarve administrative province phyto-ecological subregions. Biogeographic and bioclimatic considerations are presented, as well as the study area pedological and lithological characterization. For each of the seven climatophilous series the dynamic and catenal behaviours, as well as the main characteristic plants that constitute the successional stages, are given. The corresponding patrimonial value is studied

Analysis of the Cytisetea scopario-striati scrubs in the south-west-centre of the Iberian Peninsula

The statistical and phytosociological study of 255 relevés taken in the south-west of the Iberian Peninsula and made up of our own samples and previous publications reveals how close these relevés, previously ascribed to different syntaxa, really are. Our re-arrangement of the data leads us to propose for the territory the 15 associations already published and three new ones, namely: Genisto floridae-Adenocarpetum argyrophylli ass. nova hoc loco, Cytisetum bourgaei- eriocarpi nova, Lavandulo viridis-Cytisetum striati ass. nova hoc. loco. We also suggest a name correction, Adenocarpo anisochili-Cytisetum scoparii J.C. Costa et al. 2000 corr., and a status change, namely, Ulici latebracteati- Cytisetum striati (Costa et al. 2000) status novo

Current state of the Prunetalia spinosae communities in the centre and south of the Iberian Peninsula (Spain, Portugal)

This paper re-examines the Rhamno-Prunetea class in the centre and south of the Iberian Peninsula, especially in Andalusia. The paper also deals with the alliances Pruno-Rubion ulmifolii Lonicero-Berberidion hispanicae in the south of the Iberian Peninsula, and Berberidion vulgaris (Berberidenion seroi) in the area of Cuenca. Our analysis of 225 relevés arranged in 22 phytosociological tables helped us to re-organize the available information and subsequently propose three associations and two subassociations: Clematido vitalbae-Rosetum micranthae nova; Berberido hispanicae- Buxetum sempervirentis nova; Roso siculae-Berberidetum hispanicae Mota nova subas. prunetosum ramburii Mota nova; Lonicero arboreae-Rhamnetum cathartici Martínez-Parras and Molero 1983 subas. prunetosum ranburii nova. As a result of the study, a total of 18 syntaxa with the rank of association and four with the rank of subassociation are proposed for the south of the Iberian Peninsula

Endemic Hemicryptophyte Grasslands of the High Mountains of the Caribbean

Cano Ortiz, A., Quinto Canas, R., Pinar Fuentes, J. C., del Rio, S., Pinto Gomes, C. J., & Cano, E. (2022). Endemic Hemi-cryptophyte Grasslands of the High Mountains of the Caribbean. Re-search Journal of Ecology and Environ-mental Sciences, 2(1), 1–20. Retrieved from https://www.scipublica-tions.com/journal/in-dex.php/rjees/article/view/18

Forest fringe communities of the southwestern Iberian Peninsula Comunidades de orla forestal en el suroeste de la península ibérica

Introduction: Forest and pre-forest fringe communities in the southwest of the Iberian Peninsula are semi-shaded perennial herbs of external fringe and open areas of evergreen or semi-deciduous woodlands and their pre-forestry mantles, linked to the Stachyo lusitanicae-Cheirolophenion sempervirentis suballiance. Objective: To evaluate the chorology, ecological features and floristic circumscription of the forest fringe communities of the southwestern Iberian Peninsula. Materials and methods: Forest fringe communities adscribed to the Stachyo lusitanicae-Cheirolophenion sempervirentis suballiance were analysed, using phytosociological approach (Braun-Blanquet methodology) and numerical analysis (hierarchical cluster analysis). Results and discussion: The statistical and phytosociological analysis of six formerly described associations and the samples of this study lead us to propose a new forest fringe association: Picrido spiniferae-Cynarietum algarbiensis, dominated by Cynara algarbiensis Coss. ex Mariz. This forest fringe community is characteristic of the thermomediterranean to mesomediterranean, lower sub-humid bioclimate and occurs in the potential areas of the Quercus suber L. forests (Lavandulo viridis-Quercetum suberis), mainly in the Monchique Sierran District. Conclusion: The statistical and phytosociological analysis were useful in the evaluation of forest fringe communities in the southwest of the Iberian Peninsula. Regarding the proposal of the new association Picrido spiniferae-Cynarietum algarbiensis, it is important to develop management strategies for the preservation of the endemic C. algarbiensis

Originalities of willow of salix atrocinerea Brot. in mediterranean Europe

Willow communities (genus Salix) occurring in Mediterranean Europe are presented, showing, through statistical treatment with multivariate cluster analysis, the separation of the di erent plant communities and their sintaxonomic a liation. Six willow communities have been identified, whose formations include a set of plants with high heritage value. We highlight plants with legal protection status (Annex IV and II of the Habitats Directive-92/43/EEC), endemic, rare, and endangered species such as Salix salviifolia subsp. australis, Cheirolophus uliginosus, Euphorbia uliginosa and Leuzea longifolia. Therefore, two new willow communities are proposed for the southwest of the Iberian Peninsula. The first dominated by Salix atrocinerea, Frangulo baticae-Salicetum atrocinereae ass. nova of ribatagan distribution, under acid substrates, thermomediterranean to lower mesomediterranean, dry to sub-humid. The second, dominated by the endemic Salix salviifolia subsp. australis, Clematis flammulae-Salicetum australis distributed in the Algarve, developing on neutral-basic substrates, exclusively thermomediterranous, dry to sub-humid. In both cases, there are presented on their own floristic serial, ecology, and substitution steps. A new hygrophytic meadows was also identified dominated by Molinia caerulea subsp. arundinaceae, Cheirolopho uliginosii-Molinietum arundinaceae ass. new hoc loco, which lives on substrates rich in organic matter, exclusive to the Ribatagano Sector. Through the deepening of knowledge about the composition and dynamics of riparian vegetation, it is possible to adapt management methods to sustain and protect these important edafo-hygrophilic systems in the Mediterranean.info:eu-repo/semantics/publishedVersio

Knowledge for a Better Conservation: Syntaxonomic Review of Caribbean Pine Forests (Cuba, Hispaniola)

A phytosociological review is carried out of the pine forest formations on the islands of Cuba and Hispaniola (Caribbean), due to the diversity of soils and environments. We collected 10 plant associations belonging to the class Byrsonimo-Pinetea caribaea growing on siliceous, calcareous and sandy substrates and 21 associations on special, serpentine and ophite substrates and on ultramafic rocks belonging to the class Caseario crassinervis-Pinetea cubensis, exclusive to Cuba; while the association of pine forests on serpentines in Hispaniola is included in the class Phyllantho orbicularis-Neobracetea valenzuelanae with a Caribbean distribution. The comparative phytosociological and statistical study reveals phytosociological anomalies in the inclusion of various syntaxa, and in the description of other syntaxa according to the International Code of Phytosociological Nomenclature (ICPN). We therefore propose a change in status for several of the subassociations described: subass. ilicetosum repandae: syn. var. con Ilex repanda; subass. schmidtottietosum shaferi: syn. var. with Schmidtottia shaferi; subass. acrosynanthetosum trachyphylli: syn. var. with Acrosynanthus trachyphyllus; subass. psychotrietosum grandis: var. con Psychotria grandis; subass. notodonetosum roigii: syn. var. with Notodon roigii. We also propose a nomen novum: jaquinietosum oxhyphyllae Reyes & Acosta 2012 ex Cano et al. hoc loco