1,720,979 research outputs found
(111)-oriented Sn-doped BaTiO3 epitaxial thin films for ultrahigh energy density capacitors
No full textDespite the significant advancements of dielectric materials, the energy density values of dielectric capacitors are extremely low compared to those of other energy storage systems, e.g., batteries and fuel cells. The deposition of solid solution of ferroelectric and paraelectric multicomponent thin films are the most widely used approach to enhance the energy density of dielectric capacitors; however, it is extremely difficult to determine the optimized composition ratio of two or three components. In this study, we develop ultrahigh energy density singlecomponent Sn-doped BaTiO3 (BTS) epitaxial thin film capacitors. An ultrahigh energy density of 92.5 J/cm3 and energy efficiencies above 78% were successfully achieved in (111)-oriented BTS epitaxial thin film capacitors. These excellent results were attributed to the formation of multi-nanodomains accompanied by delayed polarization saturation, low remnant polarization, high breakdown strength, and high cycling stability. Engineering multi-nanodomains through chemical doping and epitaxial orientation is a facile approach to develop energy-efficient ultrahigh energy density capacitors. This approach can be extended for the design of other single-component-based energy-efficient dielectric capacitors with ultrahigh energy density.
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
Zn anode with hydrophobic and ferroelectric P(VDF-TrFE) layers for dendrite-free aqueous Zn-ion batteries
No full textZn anodes are highly promising aqueous battery materials due to their abundant sources, environmental friendliness, and high theoretical capacity of 820 mAh/g. Nevertheless, Zn undergoes dendritic growth and side reactions in mildly acidic electrolytes, leading to shorter cycling lifetimes. Herein, a layer of poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) was spin-coated onto a Zn anode to address this issue. The coated layer physically and electrically blocked contact between the Zn surface and the electrolyte due to its hydrophobic nature. Additionally, the ferroelectric properties of crystalline P(VDF-TrFE) (c-P(VDF-TrFE)) facilitated mass transport and homogenized the electric field, resulting in consistent plating and stripping of Zn ions beneath the film. As a result, the c-P(VDF-TrFE) coating on the Zn symmetric cell led to a stable overpotential (<40 mV) and long cycling lifetimes of more than 350 h (1 mA cm(-2), 0.5 mAh cm(-2)). Even with current conditions of 5 mA cm(-2) and 0.5 mAh cm(-2), the c-P(VDF-TrFE)-coated Zn symmetric cell demonstrated stable operation for over 600 h. Furthermore, a Zn||MnO2 full cell exhibited high capacity retention after 1000 cycles.
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
Low-Temperature Growth of Ferroelectric Hf0.5Zr0.5O2 Thin Films Assisted by Deep Ultraviolet Light Irradiation
No full textLow-temperature deposition of inorganic ferroelectric (FE) thin films is highly demanded for lowering the environmental impact through lesser energy consumption. Doped HfO2-based FE thin films commonly require high crystalline temperature (>450 degrees C) to exhibit ferroelectricity. Here, we report that the crystallization temperature of the metastable orthorhombic (O) phase in Hf0.5Zr0.5O2 thin films can be lowered to 350 degrees C via a deep ultraviolet (DUV) irradiation process carried out before rapid thermal annealing (RTA). The DUV irradiation initializes a nucleation process of the crystal growth through photochemical cleavage of organic residues, followed by the densification of metal oxide films, and the subsequent RTA at 350 degrees C crystallizes the Hf0.5Zr0.5O2 thin film with a higher O-phase fraction. The DUV-irradiated films annealed at 350 degrees C exhibited FE characteristics, whereas the non-irradiated films annealed above 450 degrees C become FE. Our study suggests that DUV irradiation can be successfully utilized to lower the crystallization temperature of HZO thin films and can lead to the realization of flexible FE random access memories.
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