1,720,958 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
Funktionalisierung von Kohlenstoffnanoröhren mit schaltbaren Molekülen
Full text linkEidesstattliche Erklärung iii Zusammenfassung/Summary v Curriculum Vitae ix
1\. Carbon Nanotubes 5 1.1. Graphene . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . 6 1.2. Zone Folding . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . 10 1.3. Optical Properties of Carbon Nanotubes . . . .
. . . . . . . . . . . 15 2\. Functionalization of Carbon Nanotubes 23 2.1.
Covalent Functionalization of Carbon Nanotubes . . . . . . . . . . 24 2.2. Non
Covalent Functionalization . . . . . . . . . . . . . . . . . . . . 26 2.3.
Solvatochromic Shifts . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3\. Experimental Methods 29 3.1. Absorption Measurements . . . . . . . . . . .
. . . . . . . . . . . . 29 3.2. Photo Luminescence Excitation . . . . . . . .
. . . . . . . . . . . . 31 4\. Amphiphile Engineering 33 4.1. Sample
Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.2.
Alkyl Chains as Nanotube Anchors . . . . . . . . . . . . . . . . . . 36 4.3.
Dendron size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.4. Linker Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
45 4.5. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 49 xi Contents 5\. Conformational Switch Functionalization 51 5.1.
Conformational Switches . . . . . . . . . . . . . . . . . . . . . . . . 52
5.2. Previous Experiments . . . . . . . . . . . . . . . . . . . . . . . . . .
55 5.3. Reversible De-bundling of CNTs . . . . . . . . . . . . . . . . . . . .
58 5.4. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 63 6\. Dipole Switch Functionalization of CNTs 65 6.1. Spiropyran . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . 66 6.2. Sample
Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 6.3.
Pyrene-Spiropyran Functionalization . . . . . . . . . . . . . . . . . 69 6.4.
Decreasing the Tube-Switch Separation . . . . . . . . . . . . . . . . 74 6.5.
Comparing both Spiropyran Dyads . . . . . . . . . . . . . . . . . . 76 6.6.
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 7\.
Micelle Swelling 83 7.1. Concept . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . 83 7.2. Sample Preparation . . . . . . . . . . . . . . . .
. . . . . . . . . . . 84 7.3. Results . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . 87 7.4. Summary . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . 95 Conclusion 97 Bibliography I A. Appendix A
XIIIIn this work, we investigated functionalization of carbon nanotubes using
conformational and dipole switches as a way of altering the tubes’
optoelectronic properties. Encapsulating nanotubes with the conformational
azobenzene switches, we were able to achieve reversible precipitation of
carbon nanotubes in water. Over several switching cycles, consisting of UV
irradiation, followed by visible irradiation and sonication, we were able to
reversibly induce the formation of nanotube bundles. This mechanism could be
used to achieve light induced spatial directed deposition of carbon nanotubes
as a way of preparing micro-size patterned surface structures. Pyrene-
spiropyran derivatives with different separation lengths between anchor and
dipole were used to non covalently disperse CNTs in THF while retaining the
tubes’ pristine 1D properties. The different tube-switch distance in both
compounds was found to induce a red shift in the range of up to 14 meV in the
E22 transitions between the two samples, even in the SP form confirming
theoretical expectations. At close distances, the MC form was found to be
stabilized. However, as the switch is sensitive to light irradiation, PLE
measurements investigating the influence of the switch state on the optical
properties could not be conducted. As a natural prosecution of this work,
transport measurements could be exploited to confirm the alteration of the
nanotubes’ electronic properties depending on the switch state. As the tubes
are functionalized in solution, they can be readily drop cast onto a given
substrate, contacted and measured. To confirm the different influence of SP
and MC on the nanotubes as theoretically predicted, nanotubes were solubilized
in water using SDS. SP/MC was then adsorbed onto the tube surface, using
micelle swelling. In good agreement with theory, peak shifts of up to 13 meV
between SP and MC functionalized samples were found. This shift was shown to
depend on the number of switches inserted into the micelles and is, thus,
tunable in a continuous fashion. Further, the average luminescence per tube in
the MC functionalized samples was significantly quenched, while in the SP
functionalized it actually increased. A possible explanation for this is the
planar geometry of the MC molecule giving rise to a large de-localized pi-
orbital able to interact with the nanotube pi-orbitals. Upon adsorption SP and
MC molecules are unable to undergo isomerization. However, the characteristic
MC absorption bands can be observed even in the SP samples, while the MC
compounds exhibit an additional peak attributed to stacked MC (either MC-MC or
MC-tube stacked). To understand the exact behavior of both, SP and MC after
infiltrating the micelles, further research is needed.In der vorliegenden Arbeit wurde die Funktionalisierung von
Kohlenstoffnanoröhren mit molekularen Konformations- und Dipolschaltern
untersucht. Ziel war es, die optoelektronischen Eigenschaften der Nanoröhren
durch Änderung des Schaltzustands reversibel zu beeinflussen. Mittels
azobenzolbasierter Konformationsschalter konnte die Wasserlöslichkeit von
Nanoröhren reversibel geschaltet werden. Über mehrere Schaltzyklen, bestehend
aus UV-Bestrahlung, gefolgt von Bestrahlung mit sichtbarem Licht und
anschließender milder Ultraschallbehandlung, war es möglich, die Formation und
Auftrennung von Nanoröhrenbündeln in Wasser wiederholt zu schalten. Mit dieser
Methode wäre es möglich, durch lokale Bestrahlung mit UV-Licht und die daraus
resultierende Ablagerung von Nanoröhren, mikrometergroße Oberflächenstrukturen
zu erzeugen. Kohlenstoffnanoröhren wurden mittels Pyren-Spiropyran-
Dipolschaltern unterschiedlicher Länge in THF gelöst. Da die Bindung zwischen
Pyren und Nanoröhren nichtkovalent ist, blieben hierbei die eindimensionalen
Quanteneigenschaften der Röhren erhalten. Die Variation des Abstands zwischen
Nanoröhren und Spiropyran führte zu einer Rotverschiebung der
E22-Übergangsenergien von bis zu 14 meV - schon in der Spiropyran-Form. Des
Weiteren führte ein geringerer Abstand zwischen Röhre und Schalter zu einer
Stabilisierung der Merocyanin-Form. Aufgrund der Sensitivität der
Schaltermoleküle gegenüber der Bestrahlung mit sichtbarem Licht war es nicht
möglich, den Einfluss des Schaltzustands auf die optischen Eigenschaften der
Röhren zu messen. Aufbauend auf den Ergebnissen der vorliegenden Arbeit wäre
es allerdings möglich, Änderungen der elektronischen Eigenschaften z.B. durch
Messung des elektronischen Transports zu ermitteln. Um den theoretisch
vorhergesagten Einfluss des Schaltzustands auf die Nanoröhren zu überprüfen,
wurden Nanoröhren mittels SDS (Sodium Dodecyl Sulphate) in Wasser gelöst.
Spiropyran/Merocyanin (SP/MC) wurde anschließend mittels des sogenannten
"Micelle Swelling" Verfahrens, bei dem Fremdstoffe in bestehende Mizellen
eingeschleust werden, auf die Nanoröhrenoberfläche aufgebracht. In guter
Übereinstimmung mit der Theorie wurden Peakverschiebungen von bis zu 13 meV
zwischen mit SP und MC funktionalisierten Röhren ermittelt. Es wurde gezeigt,
dass diese Verschiebung von der Anzahl der aufgebrachten Schalter abhängt und
somit quasikontinuierlich verändert werden kann. Die durchschnittliche
Lumineszenz MC funktionalisierter Nanoröhren ist gegenüber der lediglich mit
SDS funktionalisierter Röhren stark verringert. Im Gegensatz dazu zeigen die
SP funktionalisierten Röhren leicht erhöhte Lumineszenz. Eine mögliche
Erklärung hierfür liefert die planare Geometrie des MC-Moleküls, welche
Interaktionen zwischen den pi-Orbitalen von Schaltern und Röhren ermöglicht.
Nach der Adsorption wird auch das Schaltverhalten der SP- und MC-Isomere
unterbunden. Die charakteristischen Absorptionsspektren von Merocyanin können
auch in den mit SP funktionalisierten Proben gefunden werden. In den MC
funktionalisierten Proben jedoch tritt ein weiteres Band auf, welches auf
agglomeriertes MC hinweist (entweder MC-MC oder Röhre-MC). Weitere Forschung
ist notwendig, um das genaue Verhalten beider Isomere (SP und MC) nach dem
Einschleusen in die Mizellen zu verstehen
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
- …
