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
Ligand field and magnetic excitations in High Entropy Oxides studied by RIXS
Full text linkLAUREA MAGISTRALEGli ossidi ad alta entropia (High Entropy Oxides, HEOs) sono una emergente classe di materiali ad elevato disordine configurazionale. Il crescente interesse diffusosi nella comunità della scienza dei materiali è motivato dalle proprietà uniche di questi ossidi, tra le quali citiamo bassa conduttività termica, costante dielettrica colossale e conduttività superionica. Questo lavoro di tesi propone un innovativo studio sulle proprietà strutturali, elettroniche e magnetiche di prototipici HEOs basato sulla tecnica resonant inelastic x-ray scattering (RIXS). In particolare, abbiamo testato i composti a struttura rock-salt MgCuNiCoZnO (Mg-CNCZ) e CuNiCoZnO (CNCZ), il secondo ottenuto rimuovendo dal processo di sintesi il composto precursore MgO. Le misure RIXS sono state effettuate alla soglia L3 del rame, a diverse geometrie di scattering e polarizzazione incidente. Le eccitazioni di campo ligante, incluse le dd e le eccitazioni charge-transfer, evidenziano una considerevole distorsione di tipo Jahn-Teller delle unità ottaedriche CuO6, che risulta maggiore nel composto Mg-CNCZ, e ci permettono di stimare il guadagno energetico associato alla distorsione, un’informazione assente nella letteratura. La regione spettrale a bassa energia evidenzia picchi che possono essere assegnati a eccitazioni magnetiche. La caratteristica principale è l’osservazione del fatto che l’energia del picco magnetico in Mg-CNCZ è minore che in CNCZ, a causa della presenza di un extra ione non magnetico nel reticolo, che riduce, in media, la forza dell’interazione magnetica: sulla base di questa affermazione, possiamo spiegare quantitativamente le energie relative dei picchi magnetici nei due sistemi e notare che il RIXS sonda eccitazioni collettive che sono eccitate coerentemente nei siti risonanti. Alla luce di questo, abbiamo dato una spiegazione all’andamento delle eccitazioni magnetiche in funzione di variazioni di momento trasferito nel contesto del modello di Heisenberg, con un effettivo accoppiamento antiferromagnetico di approssimativamente 22 meV. Questo lavoro dimostra che il RIXS fornisce abbondanti informazioni sulle proprietà strutturali, elettroniche e magnetiche di Mg-CNCZ e CNCZ, e potrebbe eventualmente fare lo stesso per molti altri HEOs.High Entropy Oxides (HEOs) are an emergent class of materials characterized by high configurational disorder. The growing interest in these materials is motivated by their unique properties, including low thermal conductivity, colossal dielectric constant and superionic conductivity. This work proposes the very first study of the structural, electronic and magnetic properties of prototypical HEOs based on resonant inelastic x-ray scattering (RIXS). Specifically, rock-salt compounds MgCuNiCoZnO (Mg-CNCZ) and CuNiCoZnO (CNCZ) have been tested, where the latter has been obtained by removing the precursor oxide MgO from the synthesis process. RIXS measurements have been performed at the copper L3 absorption edge, at distinct scattering geometries and incident photon polarization. Ligand field, including dd and charge-transfer, excitations evidence a sizeable Jahn-Teller distortion of the CuO6 octahedra, which is larger for Mg-CNCZ than for CNCZ, and allow us to estimate the energy gain associated to the distortion, a missing information in the literature. The low-energy spectral region shows features, which can likely be assigned to magnetic excitations. Our major clue is the observation that the energy of the magnetic peak in Mg-CNCZ is lower than in CNCZ because of the extra non-magnetic ion present in the lattice, which reduces the effective magnetic interaction strength on average: based on this argument, we can quantitatively explain the relative energies of the magnetic peaks in the two systems and note that RIXS effectively probes collective excitations that are coherently excited at multiple resonant sites. In light of this, we could explain the momentum dependence of magnetic excitations within the framework of a simple Heisenberg model with an effective antiferromagnetic coupling of approximately 22 meV. This works demonstrates that RIXS provides a wealth of information about the structural, electronic and magnetic properties of Mg-CNCZ and CNCZ, and could possibly do the same for many other HEOs
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
Optical and structural properties of p-doped Ge/SiGe multiple quantum wells for mid-infrared photonics
Full text linkWe present a detailed study of hole-doped Ge/SiGe multiple quantum wells as a promising material platform for mid-infrared photonics. The heterostructures were grown on SiGe virtual substrates using low-energy plasma-enhanced chemical vapor deposition. Structural and compositional analyses via atom probe tomography and x-ray diffraction were employed to assess the crystal quality and retrieve the compositional profiles. The optical response of the samples, in the 4-12-mu m wavelength range, was investigated as a function of the temperature and complementary Hall-effect measurements were performed providing insights into the temperature evolution of the electrical transport properties. In addition, a well-established tight-binding model was used to reproduce and interpret the experimental results starting from the calculated valence band structure
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
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