1,721,022 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
Modulation of Asymmetric Magnetic Domain-Wall Motion via Noncolinear Interlayer Exchange Coupling
No full textThe search of scalable approach to design field-free deterministic switching is currently a key challenge. Here, we investigate current and magnetic driven magnetization switching in a T-type magnetic heterojunction with a structure composed by a hybrid synthetic antiferromagnet (SAF) Co/Ta/CoTb/Pt, where the bottom Co layer has in-plane magnetic anisotropy (IMA) and the top CoTb layer has perpendicular magnetic anisotropy (PMA). The interlayer exchange coupling (IEC) interaction allows a tilted easy axis of the perpendicular CoTb layer. The main result achieved is the field-free magnetization switching driven by spin-orbit torque (SOT) with a switching direction (clockwise or counterclockwise), which can be controlled by the in-plane direction of the Co magnetization. Meanwhile, we demonstrate that the IEC also induces the asymmetric bubble expansion in the CoTb layer in field-driven experiments and favors the propagation of the domain walls (DWs) with internal magnetization antiparallel to the in-plane IEC field. Our results demonstrate versatile control of the DW motion by noncollinear IEC, which paves a potential way for designing energy-efficient spintronic memory and logic devices, as well as provides a promising and high-efficiency approach for detecting the IEC type by magneto-optical Kerr effect (MOKE) in T-type magnetic heterojunction
Preparation and characterization of urea-formaldehyde resin/reactive kaolinite composites
No full textNovel urea-formaldehyde resin/reactive kaolinite composites containing 20-40 wt% kaolinite were prepared by in situ polymerization. The kaolinite was modified with tetraethoxysilane and a silane coupling agent to introduce reactive groups. Fourier-transform infrared spectroscopy and X-ray diffraction confirmed preparation of the urea-formaldehyde resin/reactive kaolinite composites. The composite morphology was investigated using scanning electron microscopy; the composites consisted of uniform spherical particles. The surface chemical components of the composites were determined using energy-dispersive X-ray spectroscopy. The spectra showed that the reactive kaolinite was encapsulated by the urea-formaldehyde resin. The thermal properties of the composites were examined using differential scanning calorimetry and thermogravimetric analysis. The results showed that their thermal stability was much better than that of pure urea-formaldehyde resin. Reactive kaolinite addition greatly decreased formaldehyde emissions and improved the water resistance of the composites. A mechanism for urea-formaldehyde resin/reactive kaolinite composite synthesis is proposed. (C) 2015 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved
Preparation and Characterization of Poly(methyl methacrylate)/Reactive Montmorillonite Nanocomposites
No full text
The poly(methyl methacrylate) (PMMA)/reactive montmorillonite nanocomposites were prepared by emulsion polymerization. The double bonds were introduced to both the surfaces and interlayers of the montmorillonites to obtain the reactive montmorillonites. The structure of the nanocomposites measured by wide angle X-ray diffraction (WAXD) indicated that the montmorillonites were exfoliated. The average molecular weight of the nanocomposites revealed by gel permeation chromatography (GPC) was larger than that of pure PMMA. The results of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicated that the thermal properties of the nanocomposites were enhanced and could be affected by the amount of the reactive montmorillonites. In addition, the tensile properties of the nanocomposites measured by an Instron testing machine improved and the nanocomposites including 3 wt% reactive montmorillonites showed the best tensile strength. The Young's modulus increased with the addition of the reactive montmorillonites. The aging properties of the nanocomposites had an improvement compared with pure PMMA. The optical properties assessed by UV-Visible spectroscopy revealed that the transmittance decreased as the amount of the reactive montmorillonites increased. Finally, the mechanism to prepare PMMA/reactive montmorillonite nanocomposites was proposed. (C) 2015 Society of Plastics Engineers</p
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
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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