112,201 research outputs found
Synthesis of new red photoluminescent Zn(II)-Salicylaldiminato complex
No full textWe report the preparation and photophysical properties of a new zinc (II) complex of the donor-acceptor-donor (D-A-D) type ligand N,N'-bis(2-hydroxy-1-naphthylidene)-diaminomaleonitrile (H2L). The molecular structure of the (ZnL)center dot DMFI center dot DMF complex was determined by single crystal X-ray crystallography. The complex exhibits remarkable optical features attributed to the intramolecular charge transfer (ICT) with a striking red emission. Fluorescence studies of H2L and ZnL reveal that the quantum yield strongly increases upon coordinatio
Synthesis and characterization of the dihydrosalpren ligand (H2L1) and of its trinuclear Ni(II) complex
No full textThe synthesis of the new unsymmetrical tetradenclate Schiff ligand N-(2-hydroxybenzyl)-N'-(2-hydroxybenzylidene)-1,3-diaminopropane (H2L1) is reported. The ligand comprises two different coordination moieties: a rigid salicylaldimmine unit and a more flexible (2-hydroxybenzyl)-amino (hydrogenated salicylaldimmine) unit. The reaction of H2L1 with Ni(OAc)(2)center dot 4H(2)O (1:1 molar ratio) leads to the spontaneous formation of a trinuclear complex with composition ({Ni(L-1)OH2](2)(OAc)(2)Ni}center dot 2H(2)O, characterized by X-ray crystallography, where two [Ni(L-1)] units act as O,O-bidentate chelate to a Ni(II) ion
Wind speed and temperature trends impacts on reference evapotranspiration in Southern Italy
No full textIn this study, the impacts of both temperature and wind speed trends on reference evapotranspiration have been assessed using as a case study the Southern Italy, which present a wide variety of combination of such climatic variables trends in terms of direction and magnitude. The existence of statistically significant trends in wind speed and temperature from observational datasets, measured in ten stations over Southern Italy during the period 1968–2004, has been investigated. Time series have been examined using the Mann–Kendall nonparametric statistical test in order to detect possible evidences of wind speed and temperature trends at different temporal resolution and significance level. Once trends have been examined and quantified, the effects of these trends on seasonal reference evapotranspiration have been evaluated using the FAO-56 Penman–Monteith equation. Results quantified the effects of extrapolated temperature and wind speed trends on reference evapotranspiration. Where these climatic drivers are on the same direction, reference evapotranspiration generally increases during the growing season due to a nonlinear overlapping of effects. Whereas wind speed decreases and temperature increases, there is a sort of counterbalancing effect between the two considered climatic forcing in determining future reference evapotranspiration
Understanding the Accelerating Effect of - Caprolactam on the Formation of Urethane Linkages
No full textThe accelerating role of -caprolactam on the formation of urethane linkages is studied in
the case of the reaction between toluene 2,4-diisocyanate and n-propanol in carbon tetrachloride at room
temperature. FT-IR spectroscopy is exploited to follow the consumption of the isocyanate groups. The
comparison between the rate of the reactions carried out in the presence and absence of a catalytic amount
of -caprolactam shows its accelerating effect. The acylurea-like derivative 1-methyl-2,4-[(2-oxoazepane-
1-carbonyl)amino]benzene has been prepared and identified as the real catalytic species formed in situ
as a result of the reaction between toluene 2,4-diisocyanate and -caprolactam. A kinetic model is proposed
to analyze the experimental data, and B3LYP/6-31+G* calculations are exploited to investigate the
structure of 1-methyl-2,4-[(2-oxoazepane-1-carbonyl)amino]benzene and clarify the structural features
leading the catalytic activity
Mappatura del deflusso annuo superficiale in Sicilia
No full textNella risoluzione di numerosi problemi pratici dell’idrologia delle acque superficiali è importante
poter far affidamento su informazioni relative ai deflussi che siano contemporaneamente affidabili e
diffuse sul territorio.La creazione di uno strumento capace di restituire il deflusso e soprattutto la
portata che attraversa una determinata sezione di un corso d’acqua è di fondamentale importanza sia
per la pianificazione delle risorse idriche in una data regione sia per l’individuazione delle possibili
zone soggette al rischio della desertificazione. La stima del deflusso superficiale permette inoltre la
determinazione dei concentrazione degli inquinanti, concentrati o diffusi, nei corpi idrici negli studi
relativi alla qualità delle acque (come ad esempio i piani di tutela delle acque) noto che sia il carico
totale. Obiettivo di questo lavoro è la mappatura del deflusso superficiale a scala annuale relativo al
territorio siciliano attraverso l’utilizzo delle tecniche GIS utilizzando le serie storiche degli afflussi
e dei deflussi medi mensili e annui forniti dall’Ufficio Idrografico Regionale (UIR). Tale lavoro,
basato sull’impiego dei rapporti adimensionali fra gli L-moments e di due test statistici, prevede la
suddivisione della regione in zone idrometriche omogenee; per ciascuna delle quali viene
individuata un modello di trasformazione afflussi-deflussi a scala annua. I risultati più importanti
sono rappresentati da strati informativi (trasformati anche in mappe) che forniscono a scala
regionale della Sicilia, a risoluzione 100 m il deflusso medio annuo prodotto e l’andamento delle
portate medie annue
A Self-Assembled Dinuclear Double-Stranded Helicate Based on a Square-Planar Coordination Geometry
No full textThe nickel(II) complex of a new bis-N,O-bidentate Schiff base, in which two salicylaldiminate units are connected by an alpha,alpha'-dioxo-ortho-xylidene spacer via the 3-position of salicyl moieties, was structurally characterised in the solid state and in solution as a dinuclear double helicate based on a square-planar coordination geometry
Population abundance, structure and movements of the European pond turtle, Emys orbicularis (Linnaeus 1758) based on capture-recapture data in a Venice Lagoon wetland area, Italy
No full textA freshwater turtle monitoring programme along the inland margins of the Venice lagoon was initiated in 2019 in collaboration with the World Wild Fund for Nature (WWF-Italy). From a total of 336 European pond turtles (Emys orbicularis) captured and marked, 97 freshwater turtles were recaptured at least once (28.9% return rate) providing important information on population size, structure and movements of mature individuals within the study area. The population size was estimated with capture-recapture method (Capture-Mark-Recapture-CMR) at 1009.4 ± 365.2 pond turtles, with a mean density of 252.3 ± 91.3 ind./ha. The analysis of the movements showed that the average distance covered intra-water bodies was: 146.79 ± 117.08 m for females and 125.43 ± 112.34 m for males. A total of 17 E. orbicularis (eight females and nine males) out of 97 turtles changed the water body during the study period from April to early September. Only a female freshwater turtle migrated in all three study sites, being recaptured 1502.32 m from the tagging site. The percentage of captures was significantly higher in two canals than in the brackish lake habitat. Further research should address spatial distribution at a finer scale to evaluate the preferential habitat for threatened E. orbicularis populations in a transitional water system as the lagoon
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Optimal Continuous Variable Quantum Teleportation with Limited Resources
No full textGiven a certain amount of entanglement available as a resource, what is the most efficient way to accomplish a quantum task? We address this question in the relevant case of continuous variable quantum teleportation protocols implemented using two-mode Gaussian states with a limited degree of entanglement and energy. We first characterize the class of single-mode phase-insensitive Gaussian channels that can be simulated via a Braunstein-Kimble protocol with nonunit gain and minimum shared entanglement, showing that infinite energy is not necessary apart from the special case of the quantum limited attenuator. We also find that apart from the identity, all phase-insensitive Gaussian channels can be simulated through a two-mode squeezed state with finite energy, albeit with a larger entanglement. We then consider the problem of teleporting single-mode coherent states with Gaussian-distributed displacement in phase space. Performing a geometrical optimization over phase-insensitive Gaussian channels, we determine the maximum average teleportation fidelity achievable with any finite entanglement and for any realistically finite variance of the input distribution
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