1,720,970 research outputs found
Au279(SR)84: The Smallest Gold Thiolate Nanocrystal That Is Metallic and the Birth of Plasmon
Get PDFWe report a detailed study on the optical properties of Au279(SR)84 using
steady-state and transient absorption measurements to probe its metallic nature, timedependent
density functional theory (TDDFT) studies to correlate the optical spectra,
and density of states (DOS) to reveal the factors governing the origin of the collective
surface plasmon resonance (SPR) oscillation. Au279 is the smallest identified gold
nanocrystal to exhibit SPR. Its optical absorption exhibits SPR at 510 nm. Powerdependent
bleach recovery kinetics of Au279 suggests that electron dynamics dominates
its relaxation and it can support plasmon oscillations. Interestingly, TDDFT and DOS
studies with different tail group residues (−CH3 and −Ph) revealed the important role
played by the tail groups of ligands in collective oscillation. Also, steady-state and timeresolved
absorption for Au36, Au44, and Au133 were studied to reveal the molecule-to-metal evolution of aromatic AuNMs. The
optical gap and transient decay lifetimes decrease as the size increases
Au21S(SAdm)15: An Anisotropic Gold Nanomolecule. Optical and Photoluminescence Spectroscopy and First-Principles Theoretical Analysis
No full textWe introduce a class of gold nanomolecules exhibiting anisotropy as a major feature by reporting steady-state and time-resolved photoluminescence and anisotropy measurements and in-depth theoretical analysis of energetics and optical response of a recently synthesized Au21S(SAdm)15 nanomolecule (SAdm = adamantanethiol). Starting from single-crystal X-ray data showing that Au21S(SAdm)15 exhibits a symmetry-broken structure, we unambiguously demonstrate how this translates into a striking anisotropy of its properties, for example, of its (chiro)optical absorption spectrum of great promise for sensing, optoelectronic, and electrochemical applications, and argue about the abundance and general significance of this class of compounds
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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