1,721,136 research outputs found
Emerging methods for fabricating functional structures by patterning and assembling engineered nanocrystals
No full textInorganic nanocrystals and nanoparticles have aroused increasing attention in the last years due to their original optoelectronic, thermodynamic, mechanical and catalytic properties, which are extremely attractive for fundamental understanding as well as for their huge potential in applications. The ability to strongly exploit the original potential of such nano-objects and access their properties relies on the ability to bridge the gap between the nanoscopic and mesoscopic scale. Indeed, to integrate nanoparticles in structures, materials and finally devices, their incorporation in processable systems, and their organization in morphologically controlled assembly and/or ordered arrays is crucial. The fabrication of 2/3 D patterned micro- and nanostructure is a promising strategy for integrating the nanoparticles in macroscopic entities in order to properly exploit their unprecedented functionality for biomedical, electronic, catalytic materials and devices. In this paper, different and complementary strategies able to engineer inorganic colloidal nanocrystals due to their organization in original functional materials and structures will be described
A new methodology for SEE testing and simulation
No full textIntegrated circuits for space application are tested at accelerators for their susceptibility to Single Event Effects. The high cost and the limited avaliability associated with accelerators testing suggest the development of new low cost techniques. Pulsed laser provides results that can be correlated with ion test results (despite the different physical interaction between semiconductor and ion or laser) and also temporal and spatial information of SEEs. CAD simulators are always used in design and they can be exploited at early stages of the project to accomplish a "smart test" procedure. This new testing methodology overcomes some limitations of laser testing: by coupling a laser equipment with a software simulator and CAD tools, an economic equipment for reliable SEE testing is obtained
Hot electron distribution in quantum cascade and single stage GaAs/AlGaAs periodic superlattice structures
No full textOptical properties of nanocomposites based on (CdSe)ZnS core shell nanocrystals in cyclic olefin copolymer
No full textIn this work, organic capped CdSe and (CdSe)ZnS core shell colloidal nanocrystals (NCs), prepared by means of thermolysis of organometallic precursors and with high control on size and size dispersion, were dispersed into a transparent and thermoplastic cyclic olefin copolymer, namely TOPAS, by using toluene as common solvent. The obtained nanocomposite material was deposited by spin coating in thin films that were investigated by UV–vis spectroscopy as well as by TEM analysis. A preliminary comparison of the luminescence properties of CdSe core and (CdSe)ZnS core shell NCs in polymer was carried out. The effect of NC concentration, time and temperature on the optical properties of the composites was determined with the aim of a potential use of these materials for permanent photonic applications. The incorporation of luminescent (CdSe)ZnS NCs in the TOPAS copolymer can be potentially effective for the fabrication of novel optical devices by nanoimprint lithography
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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