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Title: Reducing model bias in a deep learning classifier using domain adversarial neural networks in the MINER v A experiment
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  1. Recent molecular dynamics simulations revealed that 〈 c + a 〉 dislocations in Mg were prone to dissociation on the basal plane, thus becoming sessile. Basal dissociation of 〈 c + a 〉 dislocations is significant because it is a major factor in the limited ductility and high work-hardening in Mg. We report an in situ transmission electron microscopy study of the deformation process using an H-bar-shaped thin foil of Mg single crystal designed to facilitate 〈 c + a 〉 slip, observe 〈 c + a 〉 dislocation activity, and establish the validity of the largely immobile 〈 c + a 〉 dislocations caused by the predicted basal dissociation. In addition, through detailed observations on the fine movement of some 〈 c + a 〉 dislocations, it was revealed that limited bowing out movement for some non-basal portions of 〈 c + a 〉 dislocations was possible; under certain circumstances, i.e., through attraction and reaction between two 〈 c + a 〉 dislocations on the same pyramidal plane, at least portions of the sessile configuration were observed to be reversed into a glissile one. 
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  2. Chirik, Paul (Ed.)
    The design of a rigidified macrocyclic N-heterocyclic carbene (NHC) ligand led to the formation and structural characterization of in- and out-Ru carbene complexes. In this study, introduction of a conformational lock was used to rigidify heteroaryl-aryl bonds and thereby enforce a more perpendicular dihedral angle. A forcing metalation step was needed to form the isomeric Ru carbene complexes (Grubbs complexes). The major isomer had the Ru carbene fragment located outside the macrocyclic ring whereas the minor isomer had the Ru carbene inside the macrocyclic ring. The two new Ru carbene complexes are the first examples of in- and out-isomers of a Grubbs-type complex. The solid state structures of each isomeric ruthenium carbene complex was determined by x-ray diffraction studies. The two Ru complexes showed significantly different catalytic reactivity in the ring-closing metathesis (RCM) of the benchmark substrate, diethyl diallylmalonate. We performed computational studies to determine rotational barriers; scalable energetic barriers were found in the unmetallated NHC ligand, favoring the in-isomer by 2.4 kcal/mol. These calculations, coupled with attempted interconversion of isomers, support a mechanism featuring rotational isomerization of the NHC nucleophile in a preequilibrium step before metalation. 
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