1,720,963 research outputs found
Solid-State Laser Annealing (SLA) of Fully Solution-Processed Amorphous InZnO Thin-Film Transistors at Various Fluence
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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
Lasing and ion beam doping of semiconductor nanowires
Full text linkSemiconductor nanowires exhibit extraordinary optical properties like highly localized light emission, efficient waveguiding and light amplification. Even the stimulation of laser oscillations can be achieved at optical pumping, making nanowires promising for optoelectronic applications. For successful integration into future devices, three major key challenges have to be faced: 1) the understanding of the fundamental properties, 2) the modification of the emission characteristics and 3) the investigation of the efficiency-limiting factors. All key challenges are addressed in this thesis:
1) The fundamental properties of CdS nanowire have been investigated to uncover the size limits for photonic nanowire lasers. Laser oscillations were observed at room temperature and the emission characteristics were correlated to the morphology, which allowed the determination of a minimum diameter and length necessary for lasing.
2) The emission characteristics of ZnO nanowires have been successfully modified by ion beam doping with Co. The structural investigations revealed a good recovery of the ion induced damage in the crystal lattice. Optical activation of the implanted Co ions was achieved and an intense intra-3d-emission confirmed successful modification.
3) The temporal decay of excited luminescence centers strongly depends on the interplay of luminescent ions and defects, thus offering an approach to investigate the efficiency-limiting processes. Mn implanted ZnS nanowires were investigated, as the temporal decay of the incorporated Mn ions can be described by a Förster energy transfer model modified for nanostructures. The defect concentration was varied systematically by several approaches and the model could successfully fit the transients in all cases. The emission properties of Tb implanted ZnS nanowires were investigated and the temporal decay of the intra-4f-emission could also be fitted by the model, proving its accuracy for an additional element.Halbleiter-Nanodrähte besitzen außergewöhnliche Eigenschaften wie hochlokalisierte Lichtemission, exzellente Wellenleitung und Lichtverstärkung. Sogar Laseroszillationen können unter optischer Anregung stimuliert werden, wodurch Nanodrähte vielversprechend für optoelektronische Anwendungen sind. Für eine zukünftige Integration als Bauteile sind jedoch drei Herausforderungen zu überwinden: 1) Verständnis der fundamentalen Eigenschaften, 2) Modifikation der Emissionscharakteristik und 3) Untersuchung der Effizienz-limitierenden Faktoren. Alle Herausforderungen werden in dieser Arbeit angesprochen:
1) Die fundamentalen Eigenschaften anhand von CdS Nanodrähten untersucht. Laseroszillationen konnten bei Raumtemperatur beobachtet werden. Durch die Korrelation der Emissionscharakteristik mit der Morphologie konnten das Minimum des Durchmesser und der Länge für photonische Nanolaser bestimmt werden.
2) Die Emissionseigenschaften von ZnO Nanodrähten wurden gezielt über Ionenstrahl-Dotierung mit Co modifiziert. Strukturelle Untersuchungen zeigten ein gutes Ausheilen des strahleninduzierten Schaden im Kristallgitter. Die eingebrachten Co-Ionen konnten erfolgreich optisch aktiviert werden und zeigen eine intensive intra-3d-Emission.
3) Das zeitliche Abklingen der angeregten Leuchtzentren hängt stark von der Interaktion dieser mit Defekten ab, so dass darüber die Untersuchung der Effizienz-limitierenden Faktoren ermöglicht wird. Das zeitliche Abklingen von Mn in ZnS Nanodrähten wurde untersucht und die Transienten können mit einem modifizierten Förster-Energietransfer-Modell beschrieben werden. Die Defektkonzentration wurde systematisch durch mehrere Ansätze variiert. Das Modell konnte die Messdaten in allen Fällen gut wiedergeben. Die Emissionseigenschaften Tb implantierter ZnS Nanodrähte wurden charakterisiert und das zeitliche Abklingen der intra-4f-Emission kann ebenfalls mithilfe des Modells beschrieben werden, wodurch dieses für ein weiteres Element bestätigt wird
Rare earth doped zinc oxide nanowires
No full textZinc oxide (ZnO) nanowires were grown via thermal transport and subsequently doped with different concentrations of Tm, Yb, and Eu using ion implantation and post annealing. High ion fluences lead to morphology changes due to sputtering; however, freestanding nanowires become less damaged compared to those attached to substrates. No other phases like rare earth (RE) oxides were detected, no amorphization occurs in any sample, and homogeneous doping with the desired concentrations was achieved. Photoluminescence measurements demonstrate the optical activation of trivalent RE-elements and the emission of the characteristic intra-4f-luminescence of the respective RE atoms, which could be assigned according to the Dieke-diagram. An increasing RE concentration results into decreasing luminescence intensity caused by energy transfer mechanisms to non-radiative remaining implantation defect sites. Furthermore, low thermal quenching was observed due to the considerable wide band gap of ZnO
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
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