1,720,958 research outputs found
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
Chemistry of Ru(II) Complexes Bearing N-heterocyclic Carbene, Hydride, and Dihydrogen Ligands : Synthesis, Mechanistic Insights, and Applications
Get PDFIntroduction
N-heterocyclic carbenes (NHC) are strong donors and weak acceptors. Also, NHC forms strong metal-carbon bonds in metal complexes and hence complexes bearing NHC ligands are in general, thermally stable. Chemistry of NHCs and their transition metal complexes has been explored extensively in catalysis. Metal hydride or dihydrogen complexes are reactive intermediates and also employed as catalysts in several catalytic reactions such as hydrogenation, transfer hydrogenation, and hydroformylation. The binding of H2 to a metal center and its cleavage for the oxidative addition to a metal center are key steps in these catalytic reactions. There has been a substantial development in the field of dihydrogen chemistry. In particular, elongated dihydrogen complexes are of significant interest due to their relevance in hydrogenation reactions. A large number of elongated dihydrogen complexes have been reported. However, there has been no systematic study for the elongation of the H–H bond in dihydrogen complexes employing NHC’s as a co-ligand.
Objectives
The objectives of this work are as follows:
i. Synthesis and characterization of ruthenium dihydrogen complexes bearing an NHC ligand.
ii. Systematic variation in the ligand environment around a metal center for the elongation of the H‒H bond in the process of oxidative addition of H2 to a metal center.
iii. To synthesize new ruthenium hydride and dihydride complexes and explore their activities in catalysis such as hydrogenation, hydrodehalogenation, and CO2 activation.
Significant results
A series of dihydrogen complexes bearing NHC ligands of the type [RuCl(η2–H2)(CO)(IMes)(PPh3)(L)](OTf) [L = pyridine (Py), 4-methylpyridine (4MePy), acetonitrile (MeCN), pivalonitrile (Me3CCN)] have been prepared by the protonation of hydride complexes [RuHCl(CO)(IMes)(PPh3)(L)] (L = Py, 4MePy, MeCN, Me3CCN) with HOTf. The ligands (Py, 4MePy, MeCN, Me3CCN) trans to the hydride were found to be labile in all the hydride complexes. The H–H bond distances in the η2–H2 ligands of dihydrogen complexes were found to be temperature dependent. The H–H bond distances got slightly elongated (0.98-0.93 Å) with an increase in the temperature (183-233 K). Phosphine analogues, [RuCl(η2–H2)(CO)(PPh3)2(L)](OTf) [L = Py, 4MePy) of NHC dihydrogen complexes were also synthesized. The H‒H bond distances were temperature invariant (0.93 Å, 223-263 K) in these complexes.
A series of homobimetallic ruthenium hydride [{RuHCl(CO)(IMes)(PPh3)}2(NN)] (NN= 4,4′-bpy, 4,4′-dpyen, 4,4′-dpyan) [4,4′-bipyridine (4,4′-bpy); 1,2-bis(4-pyridyl)ethylene (4,4′-dpyen); 1,2-bis(4-pyridyl)ethane) (4,4′-dpyan)] complexes bearing an NHC ligand and their corresponding dihydrogen complexes of the type [{RuCl(η2–H2)(IMes)(PPh3)(CO)}2(NN)][OTf]2 (NN= 4,4′-bpy, 4,4′-dpyen, 4,4′-dpyan) have been synthesized and characterized. They are the first examples of homobimetallic dihydrogen complexes bearing NHC ligands. In addition, hydrogenation of internal and terminal alkenes was carried out using these homobimetallic hydride complexes.
NHC/PMe3 based cationic complexes of the type [RuH(CO)(IMes)(PMe3)3](X) (X = Cl, BPh4) have been synthesized and characterized using NMR spectroscopy. Partial hydrodechlorination of CHCl3 to CH2Cl2 was observed in the presence of both the complexes. In addition, these complexes were also found to be efficient for the activation of the C‒Cl bond in CH2Cl2 to form [CH2Cl.PMe3]Cl salt in the presence of excess PMe3. Notably, HD exchange in H2 molecules via CDCl3 was observed in the presence of both the complexes.
A new and efficient route has been developed for the synthesis of the ruthenium dihydride complexes [Ru(H)2(CO)(L)(PPh3)2] (L = IMes, IPr, PPh3). The reaction pathway for the synthesis of these derivatives was established by isolation of few intermediates. Insertion of CO2 into one of the Ru‒H bond of [Ru(H)2(CO)(L)(PPh3)2] (L = IMes, IPr) complexes took place to afford bidentate formate complexes [RuH(η2-O2CH)(CO)(L)(PPh3)2] (L = IMes, IPr). Structure formulation of these complexes was done using NMR spectroscopy
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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