1,721,006 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
No full text“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
No full textWe 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
No full textWe 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
Mechanistic Insights into Alkane C-H Activation and Functionalization by Metal Oxide Surfaces and Organometallic Complexes
No full textAlkanes are the major components of natural gas and petroleum; however, there are only few practical processes that can functionalize them into more valuable products such as alkene or alcohols. The reason for this difficulty is because alkanes possess strong and inert C-H bonds. The development of such a process that can convert alkanes to other more valuable functionalized hydrocarbons in a catalytic fashion would produce enormous economic benefits. The key to achieve this goal is to develop a proper catalyst. The catalysts can be organometallic complexes or metal oxide surfaces that catalyze alkane C-H activation and functionalization in homogeneous or heterogeneous conditions.
In this thesis, we apply quantum mechanics to study the known alkane functionalization reactions to provide more insight into those catalytic processes, and we further utilize our computational results to design new reaction pathways for alkane functionalization. Each chapter presented herein constitutes an independent publication focusing on different aspects of the problem.
Chapter 1: Single-Site Vanadyl Activation, Functionalization, and Reoxidation Reaction Mechanism for Propane Oxidative Dehydrogenation on the Cubic V4O10 Cluster: Vanadium oxide is a powerful heterogeneous catalyst that can convert oxidative dehydrogenation (ODH) of propane. Despite numerous studies, either computational or experimental, on this topic, no complete catalytic cycle is provided. In this paper, we examined the detailed mechanism for propane reacting with a V4O10 cluster to model the catalytic oxidative dehydrogenation (ODH) of propane on the V2O5(001) surface. We reported the mechanism of the complete catalytic cycle, including the regeneration of the reduced catalyst using gaseous O2, in which only a single vanadyl site is involved. This mechanism is applicable to propane ODH on the supported vanadium oxide catalysts where only monovanadate (O=V-(O)4-) species is present.
Chapter 2: The Magnetic and Electronic Structure of Vanadyl Pyrophosphate from Density Functional Theory: We have studied the magnetic structure of the high-symmetry vanadyl pyrophosphate, focusing on the spin exchange couplings, applying density functional theory with exact exchange and the full three-dimensional periodicity to this system for the first time. Based on the local density of states and the response of spin couplings to varying the cell parameter a, we found that two major types of spin exchange couplings originate from different mechanisms: one from a super-exchange interaction and the other from a direct exchange interaction. Based on the variations in V–O bond length as a function of strain along a, we found that the V–O bonds of V–(OPO)2–V are covalent and rigid, whereas the bonds of V–(O)2–V are fragile and dative.
Chapter 3: The Para-Substituent Effect and pH-Dependence of the Organometallic Baeyer-Villiger Oxidation of Rhenium-Carbon Bonds: Organometallic Baeyer-Villiger represents another means of oxidizing M-R to M-OR. In this work, we conducted a series of calculations with the goal of providing more insights into the reaction. We find that during this organometallic BV oxidation, the migrating phenyl plays the role of a nucleophile and the leaving group OH is nucleophile. Moreover, we also find that for R = Ph the reaction rate is much faster than that for R = Me, which is later confirmed by experiments.
Chapter 4: Carbon-Oxygen Bond-Forming Mechanisms in Rhenium Oxo-Alkyl Complexes: Intramolecular 1,2-migration of hydrocarbyl across metal-oxo bonds is one of the few means of oxy-functionalizing M-R to M-OR bonds. This strategy works for R = Ph, but fails for R = Me and Et. In this work, we study these systems with the goal of understanding the reason. We find that when R = Me and Et the α-hydrogen is very acidic and easy to abstract even with weak base, such as the counter ion of the complex, leading to unwanted by-products. We find that these side reactions can be avoided by two means: (1) use counter ions with weaker basicity to increase proton abstraction barriers, and (2) use R = iPr, which has a higher migratory aptitude, to accelerate the 1,2-migration rate.
Chapter 5: A Homolytic Oxy-Functionalization Mechanism: Intermolecular Hydrocarbyl Migration from M-R to Vanadyl Oxo: Oxy-functionalization Mδ+-Rδ- to M-OR bonds is one of the key challenges in the development of hydrocarbon hydroxylation catalysts. This can be achieved by limited means: (1) organometallic Baeyer-Villiger oxidation, and (2) intramolecular 1,2-migration of hydrocarbyl across metal-oxo bonds. In this work, we have examined C-O bond formation in the reaction of OVCl3 with Ph2Hg to generate phenol using quantum mechanics. Surprisingly, we find this reaction is through an unprecedented bimolecular, one-electron oxidation of the V-Ph bond by a second V=O moiety, not through the experimentally proposed intramolecular phenyl 1,2-migration across V=O bonds. Our calculations on the oxidation of Rh-CH3 and Ir-CH3 complexes by OVCl3 further suggest that the possibility of integrating this new oxidation mechanism into alkane oxidation catalytic cycles. We also give guidelines to choose the systems in which this oxidation mechanism may play an important role.</p
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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