2,096 research outputs found

    On the comparison of oxygen and sulfur transfer reactivities in phosphine and phosphorene: the case of R3Sb(X) carriers (X = O or S).

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    A mediated approach for an efficient metal covalent functionalization of the phosphorene surface is presented through the selective insertion of chalcogen atoms. Electronic and steric requirements have been evaluated in details

    Towards Comprehensive AI-Based Onboard FDIR: System Design and First Results

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    Health monitoring of spacecrafts is a crucial task in Space operations. Fault Detection, Isolation and Recovery (FDIR) plays a critical role in ensuring the safety and successful operation of a spacecraft by detecting and isolating faults, and then executing recovery actions. Currently, the FDIR process is carried out mostly on ground, with only anomaly detection typically performed onboard the spacecraft using out-of-limit (OOL) threshold techniques, whereas fault isolation and recovery is managed by operators on the ground. This approach has two major limitations. Firstly, OOL approach is not capable of identifying subtle anomalies that occur within the parameters’ nominal operational range, limiting its effectivity in identifying a wide range of anomalies. Secondly, the need for ground investigation to isolate the fault prior to the implementation of a recovery action introduces a delay in the overall FDIR pipeline. This approach has two major limitations. Firstly, OOL approach is not capable of identifying subtle anomalies that occur within the parameters’ nominal operational range, limiting its effectivity in identifying a wide range of anomalies. Secondly, the need for ground investigation to isolate the fault prior to the implementation of a recovery action introduces a delay in the overall FDIR pipeline

    Mozart’s music between predictability and surprise: results of an experimental research based on electroencephalography, entropy and Hurst exponent

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    OBJECTIVE: The main goal of our work was to simultaneously study musical and electroencephalogram (EEG) signal while listening to Mozart’s K448 Sonata, a piece known for the “Mozart effect”, with the aim to better understand the reasons of beneficial effect of music on the brain. DESIGN: To this purpose, in a small sample of young healthy subjects, we examined the EEG correlates of modifications of brain activity, also applying the concepts of entropy and Hurst exponent H to K448 Sonata compared to a selection of Mozart’s excerpts, so that to expose the peculiar characteristics of this compositions in terms of predictability and surprise for the listener RESULTS: Spectral analysis showed that mean beta rhythm significantly grew during the listening to K448, and that this effect remaining immediately after, but to a lesser extent. Furthermore, we found that maximum values of entropy and lower values of H were reached by K448 compared to a selection of Mozart’s pieces. CONCLUSIONS: The results support the hypothesis of an overall effect of activation of the superior cortical functions during listening to K448, and immediately afterwards, in healthy young adults, and of a greater complexity of this sonata compared to a selection of Mozart’s pieces

    Modelling Strategies for the Covalent Functionalization of 2D Phosphorene

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    The paper is an excursus on potential acid-base adducts formed by an unsaturated main group or transition metal species and P atoms of phosphorene (P n ), which derives from the black phosphorus exfoliation. Various possibilities of attaining a realistic covalent functionalization of the 2D material have been examined via DFT solid state calculations. The distribution of neighbor P atoms at one side of the sheet and the reciprocal directionalities of their lone pairs must be clearly understood to foreshadow the best possible acceptor reactants. Amongst the latter, the main group BH 3 or I 2 species have been examined for their intrinsic acidity, which favors the periodic mono-hapto anchoring at P n atoms. The corresponding adducts are systematically compared with other molecular P donors from a phosphine to white phosphorus, P 4 . Significant variations emerge from the comparison of the band gaps in the adducts and the naked phosphorene with a possible electronic interpretation being offered. Then, the P n covalent functionalization has been analyzed in relation to unsaturated metal fragments, which, by carrying one, two or three vacant hybrids, may interact with a different number of adjacent P atoms. For the modelling, the concept of isolobal analogy is important for predicting the possible sets of external coligands at the metal, which may allow the anchoring at phosphorene with a variety of hapticities. Structural, electronic, spectroscopic and energy parameters underline the most relevant pros and cons of some new products at the 2D framework, which have never been experimentally characterized but appear to be reasonably stable

    Inverted Ligand Field in a Pentanuclear Bow Tie Au/Fe Carbonyl Cluster

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    Gold chemistry has experienced in the last decades exponential attention for a wide spectrum of chemical applications, but the +3 oxidation state, traditionally assigned to gold, remains somewhat questionable. Herein, we present a detailed analysis of the electronic structure of the pentanuclear bow tie Au/Fe carbonyl cluster [Au{η2-Fe2(CO)8}2]- together with its two one-electron reversible reductions. A new interpretation of the bonding pattern is provided with the help of inverted ligand field theory. The classical view of a central gold(III) interacting with two [Fe2(CO)8]2- units is replaced by Au(I), with a d10 gold configuration, with two interacting [Fe2(CO)8]- fragments. A d10 configuration for the gold center in the compound [Au{η2-Fe2(CO)8}2]- is confirmed by the LUMO orbital composition, which is mainly localized on the iron carbonyl fragments rather than on a d gold orbital, as expected for a d8 configuration. Upon one-electron stepwise reduction, the spectroelectrochemical measurements show a progressive red shift in the carbonyl stretching, in agreement with the increased population of the LUMO centered on the iron units. Such a trend is also confirmed by the X-ray structure of the direduced compound [Au{η1-Fe2(CO)8}{η2-Fe2(CO)6(μ-CO)2}]3-, featuring the cleavage of one Au-Fe bond

    A Perspective on Recent Advances in Phosphorene Functionalization and its Application in Devices

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    Phosphorene, the 2D material derived from black phosphorus, has recently attracted a lot of interest for its properties, suitable for applications in material science. In particular, the physical features and the prominent chemical reactivity on its surface render this nanolayered substrate particularly promising for electrical and optoelectronic applications. In addition, being a new potential ligand for metals, it opens the way for a new role of the inorganic chemistry in the 2D world, with special reference to the field of catalysis. The aim of this review is to summarize the state of the art in this subject and to present our most recent results in preparation, functionalization and use of phosphorene and its decorated derivatives. In particular, we discuss several key points, which are currently under investigation: the synthesis, the characterization by theoretical calculations, the high pressure behaviour of black phosphorus, as well as decoration with nanoparticles and encapsulation in polymers. Finally, device fabrication and electrical transport measurements are overviewed on the basis of recent literature and new results collected in our laboratories

    Polimeri conduttori e metallopolimeri redox

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    Il nostro gruppo di ricerca è da anni attivo nella sintesi e caratterizzazione elettrochimica di polimeri conduttori a base tiofenica. In particolare la nostra attenzione è rivolta verso materiali costituiti da un backbone di tipo tertiofenico, che consente la polimerizzazione nelle posizioni 2 e 5, e da unità chelanti all’azoto, (terpiridine o fenantroline), che possono consentire la coordinazione con metalli di transizione all’interno del polimero ed incrementarne ulteriormente le proprietà conduttive
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