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101.
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103.
Henri Avancini Leonardo Candela Umberto Straccia 《Journal of Intelligent Information Systems》2007,28(3):253-283
We envisage an information source not only as an information resource where users may submit queries to satisfy their daily
information need, but also as a collaborative working and meeting space of people sharing common interests. Indeed, we will
present a highly personalized environment where not only users may organize (and search into) the information space according
to their individual taste and use, but which provides advanced features of collaborative work among the users. It is up to
the system to discover interesting properties about the users’ interests, relationships between users and user communities
and to make recommendations based on preference patterns of the users, which is the main topic of this paper. 相似文献
104.
This study investigated the extent to which observation of an action performed by a human actor or a robotic arm may kinematically prime the performance of an observer subsequently required to perform a similar action. In Experiment 1, an actor reached for a target presented in isolation or flanked by a distractor object. Subsequently, an observer was required to perform a similar action toward the target object, but always in the absence of the distractor. The kinematics of both the human actor and the observer were affected by the presence of the distractor. Unexpectedly, similar effects were found in the observer's kinematics during the trials in which the actor was seated in front of the observer but no action was demonstrated (catch trials). Results from 4 subsequent experiments suggest that the motor intentions of the actor can be inferred by monitoring his or her gaze. To support this conclusion, results are discussed in terms of recent work spanning many disciplines involved in combining gaze direction and body movements. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
105.
Light scattering and viscosity measurements performed in the temperature range between the θ-point and the temperature of phase separation with dilute solutions of polystyrene in cyclohexane and poly(acrylic acid) in dioxane have indicated a different mechanism of precipitation in the two systems. While polystyrene molecules give rise to progressively growing clusters the poly(acrylic acid) coils assume compact forms before precipitating. Phase separation is achieved in the former case by extensive clustering, in the latter by particle coalescence. The dimensions that the compact form of the poly(acrylic acid) molecule can reach before precipitation sets in correspond to a solid-like density inside the molecular domain. From the experimental data the temperatures characteristic for cluster formation (Tc) and for coil to globule transition (Tg) have been obtained. 相似文献
106.
A white emitting poly(phenylenevinylene) 总被引:1,自引:0,他引:1
Carmela Martinelli Umberto Giovanella Antonio Cardone Silvia Destri Gianluca M. Farinola 《Polymer》2014
A white emitting copolymer with the polyphenylenevinylene (PPV) structure is obtained via the Stille cross-coupling reaction. Substitution of hydrogen atoms with fluorine atoms on the vinylene units of poly(1,4-dialkoxyphenylenevinylene) shifts the emission from orange-red to blue. White emission is obtained by combining dialkoxyphenylenedifluorovinylene and dialkoxyphenylenevinylene units in proper ratio. The two complementary emitters are obtained separately by Stille polymerization reaction. Then, the two reaction mixtures are combined without purification in different ratios and further reacted in similar experimental conditions. A white luminescent material is obtained using 99/1 mixing ratio. OLED devices fabricated with this copolymer shows near-white emission with CIE (0.30, 0.40) and excellent stability in the range 10–200 cd/m2. 相似文献
107.
Marc Renom‐Carrasco Piotr Gajewski Luca Pignataro Johannes G. deVries Umberto Piarulli Cesare Gennari Laurent Lefort 《Advanced Synthesis \u0026amp; Catalysis》2016,358(4):515-519
Herein, we report the successful transformation of a 1st generation Grubbs metathesis catalyst into an asymmetric transfer hydrogenation (ATH) catalyst. Upon addition of a chiral amine ligand, an alcohol and a base, the 1st generation Hoveyda–Grubbs catalyst ( HG‐I ) was found to promote the enantioselective reduction of acetophenone to 1‐phenylethanol. After optimizing the order of addition and the reaction conditions, the substrate scope was assessed leading to enantiomeric excesses up to 97% ee. NMR experiments were run in order to get information about the in situ‐generated ATH catalyst. Furthermore, the possibility to perform olefin metathesis and ketone transfer hydrogenation sequentially in one pot was demonstrated, and the first tandem olefin metathesis–ketone asymmetric transfer hydrogenation was carried out.
108.
Francesco Parrillo Carmine Boccia Giovanna Ruoppolo Mario Commodo Franco Berruti Umberto Arena 《加拿大化工杂志》2023,101(1):97-109
Syngas produced by biomass and waste gasification processes must be adequately clean of tar compounds before being utilized in value-added applications. Syngas cleaning by tar cracking at high temperatures is a promising technique that can utilize different kinds of catalysts. However, their use is limited by the deposition of coke layers, which induces a masking phenomenon on the active surface, and, consequently, the rapid deactivation of the catalyst. This study addresses how the temperature (750 and 800°C) and the steam concentration (0% and 7.5%) can affect the extent of water–gas and reforming reactions between steam and coke deposits. Two catalysts were used: a market-available activated carbon and an iron-based alumina catalyst. The tests showed better performance of the Fe/γ-Al2O3 catalyst. A mass increase of the bed was measured in tests with both the catalysts, which confirms the deposition of the coke layer produced by tar dehydrogenation and carbonization. Scanning electronic microscopy-energy-dispersive X-ray analysis (SEM-EDX) and Raman spectroscopy were utilized to investigate the nature of coke layers over the catalyst surface, with the aim of acquiring information about their reactivity towards the water gas reaction. SEM-EDX observations indicate that the thickness of these carbon layers is less than 2 μm. Raman spectra suggest a negligible effect of the reaction temperature in the tested range and, in particular, that the amorphous nature of coke layers deposited in the presence of steam is relatively more graphitic than that obtained without steam. 相似文献
109.
Lucia Umberto 《机械工程学报(英文版)》2000,13(3)
Latin lettersa--V~ diedon in the mol~ d~ cellb~Vector diedon in the ~ dboc Cellc~VeCtor inchon in the moleculax ~ cellc~Speilic heat capeity(J' kg~ l' K~' )D--Finite sabin tensorE--Sthen tenSOrG~Metric ten8Orh--hanetrical ~e ie~ in themolectilar dMc cellL~an(J)m--Mass(kg) N~ n~ Of Particlesp~Hy~c mpsme(Pa)q--toe heat now rate (w.m-= )--POSihon(m)S--Vector ghhon in the molecthedwtc referee(m)S--Sness tensor(N' m-' )t~(s)T~(K)u--Vector displacement(m)~boas pennal(J)~Arbitw constant… 相似文献
110.
Umberto Basile Cecilia Napodano Francesca Gulli Krizia Pocino Riccardo Di Santo Laura Todi Valerio Basile Carlo Provenzano Gabriele Ciasca Mariapaola Marino 《International journal of molecular sciences》2021,22(17)
Myasthenia gravis with antibodies (Abs) against the muscle-specific tyrosine kinase (MuSK) is a rare autoimmune disorder (AD) of the neuromuscular junction (NMJ) and represents a prototype of AD with proven IgG4-mediated pathogenicity. Thanks to the mechanism of Fab-arm exchange (FAE) occurring in vivo, resulting MuSK IgG4 k/λ Abs increase their interference on NMJ and pathogenicity. The characterization of hybrid MuSK IgG4 as a biomarker for MG management is poorly investigated. Here, we evaluated total IgG4, hybrid IgG4 k/λ, and the hybrid/total ratio in 14 MuSK-MG sera in comparison with 24 from MG with Abs against acetylcholine receptor (AChR) that represents the not IgG4-mediated MG form. In both subtypes of MG, we found that the hybrid/total ratio reflects distribution reported in normal individuals; instead, when we correlated the hybrid/total ratio with specific immune-reactivity we found a positive correlation only with anti-MuSK titer, with a progressive increase of hybrid/total mean values with increasing disease severity, indirectly confirming that most part of hybrid IgG4 molecules are engaged in the anti-MuSK pathogenetic immune-reactivity. Further analysis is necessary to strengthen the significance of this less unknown biomarker, but we retain it is full of a diagnostic-prognostic powerful potential for the management of MuSK-MG. 相似文献