52 research outputs found
Unsupervised segmentation of irradiation\unicode{x2010}induced order\unicode{x2010}disorder phase transitions in electron microscopy
We present a method for the unsupervised segmentation of electron microscopy
images, which are powerful descriptors of materials and chemical systems.
Images are oversegmented into overlapping chips, and similarity graphs are
generated from embeddings extracted from a domain\unicode{x2010}pretrained
convolutional neural network (CNN). The Louvain method for community detection
is then applied to perform segmentation. The graph representation provides an
intuitive way of presenting the relationship between chips and communities. We
demonstrate our method to track irradiation\unicode{x2010}induced amorphous
fronts in thin films used for catalysis and electronics. This method has
potential for "on\unicode{x2010}the\unicode{x2010}fly" segmentation to
guide emerging automated electron microscopes.Comment: 7 pages, 3 figures. Accepted to Machine Learning and the Physical
Sciences Workshop, NeurIPS 202
Multiple publications: The main reason for the retraction of papers in computer science
This paper intends to review the reasons for the retraction over the last decade. The paper particularly aims at reviewing these reasons with reference to computer science field to assist authors in comprehending the style of writing. To do that, a total of thirty-six retracted papers found on the Web of Science within Jan 2007 through July 2017 are explored. Given the retraction notices which are based on ten common reasons, this paper classifies the two main categories, namely random and nonrandom retraction. Retraction due to the duplication of publications scored the highest proportion of all other reasons reviewed
Multiple publications: The main reason for the retraction of papers in computer science
This paper intends to review the reasons for the retraction over the last decade. The paper particularly aims at reviewing these reasons with reference to computer science field to assist authors in comprehending the style of writing. To do that, a total of thirty-six retracted papers found on the Web of Science within Jan 2007 through July 2017 are explored. Given the retraction notices which are based on ten common reasons, this paper classifies the two main categories, namely random and nonrandom retraction. Retraction due to the duplication of publications scored the highest proportion of all other reasons reviewed
An open database of computed bulk ternary transition metal dichalcogenides
Abstract We present a dataset of structural relaxations of bulk ternary transition metal dichalcogenides (TMDs) computed via plane-wave density functional theory (DFT). We examined combinations of up to two chalcogenides with seven transition metals from groups 4–6 in octahedral (1T) or trigonal prismatic (2H) coordination. The full dataset consists of 672 unique stoichiometries, with a total of 50,337 individual configurations generated during structural relaxation. Our motivations for building this dataset are (1) to develop a training set for the generation of machine and deep learning models and (2) to obtain structural minima over a range of stoichiometries to support future electronic analyses. We provide the dataset as individual VASP xml files as well as all configurations encountered during relaxations collated into an ASE database with the corresponding total energy and atomic forces. In this report, we discuss the dataset in more detail and highlight interesting structural and electronic features of the relaxed structures
Ring-Walking of Zerovalent Nickel on Aryl Halides
While ring-walking is a critical
step in transition metal catalyzed
cross-coupling reactions, the associated metastable intermediates
are often difficult to isolate and characterize. In this work, theoretical
structures and energetics for ring-walking and oxidative addition
of zerovalent nickel with 1-bromo-2-methylbenzene, 2-bromopyridine,
2-bromo-3-methyl-thiophene, and 2-bromopyrrole were computed
at the B3LYP-D3/TZ2P-LANL2TZ(f)-LANL08d level. The mechanisms vary
qualitatively with substrate ring size and typethe catalyst
weaves along the edges of the benzene and pyridine rings, cuts through
the interior of the thiophene ring, and arcs along the bond opposite
the nitrogen atom in the pyrrole ring. Analogous computations on the
ring-walking and oxidative addition of zerovalent palladium with 1-bromo-2-methylbenzene
reveal an energetic profile similar to that of Ni but with much weaker
overall binding to the arene. In all cases, dispersion corrections
are found to be very important for computing accurate metal–substrate
binding energies
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