1,720,983 research outputs found
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
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
Modellierung der Aktivierung von CO2 und H2O mit Kupferkomplexen, stabilisiert durch P- und N-Alken Hybridliganden
Full text linkThe aim of this work was to investigate and apply the concept of hemilability of P- and N-Alkene ligands to Cu(I) complexes. While the chemistry for P-Alkene ligands and their bidentate behavior is known for other transition metals, to the best of my knowledge there is only one published example for Cu(I), where the reversibility of the alkene coordination has not been shown yet. Not only should these bidentate ligands be able to open free coordination sites but are in addition polyene complexes. Polyene coordination is rarely observed for Cu(I) and feature highly interesting structures. P-Alkene supported complexes allowed the activation of H2O and the trapping of an Intermediate in the CO2 Reduction with Cu Hydrides. N-Alkene supported complexes showed a highly interesting coordination behavior and were tested in the electrochemical reduction of CO2
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
S‐ und P‐Stereogene Diarylamido S(O)–N–S(O) und P(O)–N–P(O) Pincer Liganden und ihre Chiralen Metallkomplexe: Erste Anwendungen in der Asymmetrischen Katalyse
No full textMain goal of this work was the development of novel optically pure S‐ and P‐stereogenic pincer architectures. The synthesis of targeted, optically pure diarylamido bis‐sulfoxide pincer ligands – designed along the lines of Ozerov’s achiral PNP analogue – was successfully implemented via reaction of (in situ lithiated or isolated) bis(2‐lithio‐4‐tert‐butylphenyl)lithiumamide with appropriate diastereomerically pure sulfinate esters by nucleophilic substitution. Hereby, the choice of S‐synthon plays a crucial role, since notable differences regarding selectivity and purification requirements were noticed. In total, three derivatives have been fully characterized by elemental analysis, spectroscopic techniques and by X‐ray diffraction. The coordination chemistry of these ligands to hard and soft transition metals and the resulting ambidentate behavior was extensively investigated. Furthermore, the isolation of chiral Ir(IV) complexes, synthesized by oxidative addition of excess iodine or bromine in aromatic solvent (i.e. in the absence of coordinating substrates), presents a highlight of this thesis. The rare oxidation state was proven by EPR and SQUID measurements and in case of the iodo derivative XRD‐suitable crystals were obtained. Ir(III) and Ir(IV) sulfoxide pincer complexes were found to be active catalysts in the transfer hydrogenation of 2‐acetonaphthone in the presence of 2‐propanol. Promising results with er‐values up to 76:24 were obtained. Exploration of sulfoxide chemistry in this thesis also opened the door for new projects regarding chiral recognition: in the presence of racemic phosphine, the Ir(I) COE complex bearing the p‐tolyl substituted S(O)–N–S(O) pincer ligand was demonstrated to form two diastereomers, which are easily distinguishable via NMR techniques.
The second part of this thesis covered the development of a synthetic route towards optically pure diarylamido and diarylthioether bis‐phosphine oxide pincer ligands. This target was achieved via two consecutive Pd-catalyzed C–P cross coupling reactions using optically pure secondary t‐butylphenylphosphine oxide as P‐synthon. Although losing the possibility for ambidentate coordination behavior, switching from chirogenic sulfoxides to phosphine oxides enhances the steric bulk of the donor functions thanks to an additional third substituent on the phosphorus atom compared to O‐bound sulfoxides. Coordination of the P-stereogenic P(O)–N–P(O) ligand to molybdenum(VI) in fact revealed a preference for a facial coordination mode in neutral complexes. Nevertheless, meridional coordination was observed for cationic species. Besides serving as ligands themselves, phosphine oxide compounds presented herein, might of course also function as precursors towards P-stereogenic phosphines. Thus, reduction of the P=O bond is the essential part of ongoing research on this project
- …
