1,721,010 research outputs found
A comprehensive dataset on two-dimensional noble metals: Theoretical insights into physical properties and metal-support interactions
No full textThis paper presents a dataset offering profound insights into the formation and physical properties of two-dimensional (2D) noble metals under various configurations, with a pri-mary focus on their role as catalysts for the hydrogen evo-lution reaction (HER). These data are of significant value to catalysis researchers, materials scientists, and computational chemists, providing them with a detailed understanding of 2D noble metals' behavior as catalysts and enabling advance-ments in their respective studies. The dataset, thoughtfully structured and meticulously documented, comprises five pri-mary sections, each housing distinct content and analyses. It offers a comprehensive view of the substrate-mediated sta-bilization and physical properties of 2D noble metals, includ-ing silver (Ag), gold (Au), iridium (Ir), osmium (Os), palla-dium (Pd), platinum (Pt), rhodium (Rh), and ruthenium (Ru). The substrates utilized include bare Si-face 4H-SiC, buffer layer (BuL), and monolayer epitaxial graphene (MEG). The data collection process involves the use of the SIESTA code for density functional theory (DFT) calculations. The vdW-BH functional is consistently applied in conjunction with a double-zeta polarized (DZP) basis set, known for its reliability in capturing nuanced interactions with noble metals. Param -eters such as an energy shift of 200 meV and a force tol-erance of 0.02 eV/A are meticulously configured for accu- rate results. In-depth structural information, including opti-mized structures in top and side views and Cartesian coordi-nates for various substrate-metal configurations, is a central component of the dataset. These structural details are piv-otal for comprehending the physical properties of 2D noble metals. Furthermore, the dataset encompasses results from charge density difference (CDD) analyses, including cube files, planar-averaged CDD curves, and 3D CDD maps. These analyses provide essential data for understanding the elec-tronic properties of these materials. The dataset also includes outcomes from charge population analyses utilizing Hirsh-feld and Voronoi schemes. These analyses offer insights into structural parameters, Hirshfeld charge magnitudes on 2D metal layers, and various energy-related metrics, further en-hancing the dataset's richness. In addition to structural data, the dataset presents atomic structures in top and side views of free-standing and substrate-supported 2D noble metals af-ter hydrogen adsorption, along with corresponding Cartesian coordinates. Gibbs free energy (AGH*) data for hydrogen ad-sorption on both free-standing and substrate-supported 2D noble metals contribute to the dataset's depth. This meticu-lously curated dataset not only serves as a valuable resource for researchers exploring the properties and behaviors of 2D noble metals but also holds significant reuse potential. Re-searchers can employ this dataset to validate their computa-tional methods and models in catalysis research, enhancing the quality and reliability of their simulations. Furthermore, it serves as a possible educational tool, fostering hands-on learning for students and emerging researchers in the field of computational materials science and catalysis, thereby pro-moting methodological consistency within the scientific com-munity.(c) 2023 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )Funding Agencies|AForsk Foundation [21-112]; Linkoping University</p
Fundamentals and Recent Advances in Epitaxial Graphene on SiC
Get PDFThis book is a compilation of recent studies by recognized experts in the field of epitaxial graphene working towards a deep comprehension of growth mechanisms, property engineering, and device processing. The results of investigations published within this book develop cumulative knowledge on matters related to device-quality epaxial graphene on SiC, bringing this material closer to realistic applications
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
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
A DFT Study of Phosphate Ion Adsorption on Graphene Nanodots: Implications for Sensing
No full textThe optical properties of graphene nanodots (GND) and their interaction with phosphate ions have been investigated to explore their potential for optical sensing applications. The absorption spectra of pristine GND and modified GND systems were analyzed using time-dependent density functional theory (TD-DFT) calculation investigations. The results revealed that the size of adsorbed phosphate ions on GND surfaces correlated with the energy gap of the GND systems, leading to significant modifications in their absorption spectra. The introduction of vacancies and metal dopants in GND systems resulted in variations in the absorption bands and shifts in their wavelengths. Moreover, the absorption spectra of GND systems were further altered upon the adsorption of phosphate ions. These findings provide valuable insights into the optical behavior of GND and highlight their potential for the development of sensitive and selective optical sensors for phosphate detection
Cd-substitution effect on photoexcitation properties of ZnO nanodots surrounded by carbon moiety
Get PDFThe geometrical structure and photoexcitation properties of Zn27-nCdnO27C42
complexes are investigated by density functional theory (DFT) and
time-dependent DFT calculations at the PBE0/6-31G*/SDD level of theory. The
cohesive energy and frequency analysis indicate that the hybrid materials are
energetically stable. In presence of Cd substituting atoms, energy gap of the
ZnO nanodots surrounded by carbon moiety is shown to decrease, as compared to
Cd-free complex. In-depth excited state analysis including charge density
difference (CDD) mapping and absorption spectrum decomposition is performed to
reveal the nature of the dominant excited states and to comprehend the Cd-to-Zn
substitution effect on the photoexcitation properties of Zn27-nCdnO27C42. A
principal possibility to enhance intramolecular charge transfer through
incorporation of certain number of Cd atoms into the ZnO nanodots is shown.
Such Cd-induced modifications in optical properties of semi-spherical
Zn27-nCdnO27C42 complexes could potentially enable use of this hybrid material
in optoelectronic and photocatalytic applications
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
Defect-Induced Modulation of a 2D ZnO/Graphene Heterostructure: Exploring Structural and Electronic Transformations
No full textThis paper presents a theoretical study on the effects of selected defects (oxygen vacancies and substitutional FeZn atoms) on the structural and electronic properties of a 2D ZnO/graphene heterostructure. Spin-polarized Hubbard- and dispersion-corrected density functional theory (DFT) was used to optimize the geometrical configurations of the heterostructure and to analyze the equilibrium distance, interlayer distance, adhesion energy, and bond lengths. Charge density difference (CDD) analysis and band structure calculations were also performed to study the electronic properties of the heterostructure. The results show that the presence of defects affects the interlayer distance and adhesion energy, with structures including oxygen vacancies and FeZn substitutional atoms having the strongest interaction with graphene. It is demonstrated that the oxygen vacancies generate localized defect states in the ZnO bandgap and lead to a shift of both valence and conduction band positions, affecting the Schottky barrier. In contrast, Fe dopants induce strong spin polarization and high spin density localized on Fe atoms and their adjacent oxygen neighbors as well as the spin asymmetry of Schottky barriers in 2D ZnO/graphene. This study presents a comprehensive investigation into the effects of graphene on the electronic and adsorption properties of 2D ZnO/graphene heterostructures. The changes in electronic properties induced by oxygen vacancies and Fe dopants can enhance the sensitivity and catalytic activity of the 2D ZnO/graphene system, making it a promising material for sensing and catalytic applications
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
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