1,721,368 research outputs found
Accelerating CO2 direct air capture screening for metal-organic frameworks with a transferable machine learning force field
No full textDirect air capture (DAC) of CO2 is necessary for climate change mitigation, but it faces challenges from low CO2 concentrations and competition from water vapor. Metal-organic frameworks (MOFs) hold significant promise for DAC owing to their high surface area and adsorption-based capture processes. However, identifying optimal MOFs is hindered by structural complexity and vast chemical diversity. Here, we introduced a machine learning force field (MLFF) tailored for CO2 and H2O interactions in MOFs by fine-tuning a foundation model. To address smoothing issues and catastrophic forgetting, we curated the GoldDAC dataset and introduced a continual learning scheme. We further developed DAC-SIM, a molecular simulation package integrated with MLFF, including a Widom insertion. Then, we screened an extensive MOF database, uncovering high-performing MOFs and identifying chemical features for DAC applications. This approach overcomes prior limitations in describing MOF-CO2 and MOF-H2O interactions, providing a scalable and accurate framework for DAC research of porous materials.
Low-dimensional formamidinium lead perovskite architectures via controllable solvent intercalation
Full text linkWe report the formation of a new class of solvent-intercalated two-dimensional (SI-2D) formamidinium lead halide perovskites. They can be mixed with three-dimensional (3D) stoichiometric perovskites by controlling the ratio of the precursor solutions. The composite leads to greatly improved photoluminescence quantum yield (PLQY) over the 3D compound. The enhanced PLQY is attributed to a type-I band alignment between the 3D and SI-2D, as revealed by first-principles calculations, which results in confined excitons with enhanced radiative recombination. The films exhibited excellent thermal and air stability retaining PLQY > 20% over 2 months in ambient conditions. Assemblies of halide perovskites with mixed dimensionality offer a pathway to enhance optoelectronic performance and device lifetimes
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
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
Structural dynamics of hybrid lead halide perovskites with machine learning
No full textIn this thesis, I present a unified computational strategy for investigating the structure and dynamics of lead halide perovskites, which remain at the forefront of research for next-generation solar cells and optoelectronic devices. The methods combine on-the-fly force field training connected to machine learning (ML) architectures such as the Gaussian Approximation Potential, Allegro, and MACE, with an automated Python workflow. My code PDynA was built to efficiently quantify perovskite structural descriptors (e.g., octahedral tilting, distortion modes, and molecular orientations). This integrated approach is applied to both simple, pure compositions and more intricate mixed perovskites, where varying A-site cations and halide ratios drive multiple phase transformations and dynamic effects.Open Acces
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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