1,720,967 research outputs found
Studio della modulazione del potenziale redox di SAM elettroattivi legati covalentemente ad elettrodi di Si(100) attraverso differenti gruppi funzionali
No full textMolecular and Electronic Properties Transferred to Silicon via Wet-Chemistry Surface Nanofunctionalization: Ethynylferrocene on Si(100)
No full textIn the frame of our research activity on covalent anchoring of functional molecules on Si oriented surfaces, we report here on the hybrid species resulting from the reaction of ethynylferrocene with H-Si(100) either in a single, direct step, or after production of a self-assembled alpha,omega-bifunctional alkyl monolayer. In the former approach, a short Si-C covalent bond is established through visible-light activation of the unsaturated side arm of ethynylferrocene via an extra-mild approach. In the latter case, an azide-alkyne Huisgen cycloaddition reaction ("click" chemistry) is induced between the C C group of the molecule and the -N-3 terminations of undecyl hydrocarbon chains pre-assembled onto H-Si(100). These two routes lead to electroactive monolayers wherein the ferrocene head groups are respectively located close to or far from the Si surface. This allows for a fine tuning of the properties of the resulting hybrids on Si, in terms of distinct redox potentials, electron transfer rate constants, oxidation resistance. The different reaction steps have been monitored with X-ray Photoelectron Spectroscopy (XPS), in order to evaluate the presence and the chemical nature of the anchored species, while electrochemical measurements have evidenced reversible redox responses of the resulting SAMs
REDOX-ACTIVE HYBRIDS FOR MOLECULAR ELECTRONICS: FERROCENE DERIVATIVES ANCHORED ON SILICON (100)
No full textCOMUNICAZIONE ORAL
Theoretical models of the interaction between organic molecules and semiconductor surfaces
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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