Monolayer transition metal dichalcogenides (1L-TMDs) have tremendous potential as atomically thin, direct bandgap semiconductors that can be used as convenient building blocks for quantum photonic devices. However, th...
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Compositional design of the thermo-optic coefficient of optical fiber is discussed. The influences of P2O5, B2O3, SrO, and F are presented. Phosphorus borosilicate compositions appear to be the most attractive for rea...
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We report the ac magnetic susceptibility, electrical resistance, and x-ray diffraction measurements of PtHx(x≃1) in diamond anvil cells, that reveal the superconducting transition. At 30 GPa, when PtHx is in a P63/mmc...
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We report the ac magnetic susceptibility, electrical resistance, and x-ray diffraction measurements of PtHx(x≃1) in diamond anvil cells, that reveal the superconducting transition. At 30 GPa, when PtHx is in a P63/mmc structure, PtHx exhibits the superconducting transition at 7 K. Remarkably, the observed Tc is higher than that of powdered Pt by more than three orders of magnitude. It is suggested that the noble metals in the periodic table of elements possibly form a region where hydrides have higher Tc than elements.
Interest has been growing in defects of halide perovskites in view of their intimate connection with key material optoelectronic properties. In perovskite quantum dots (PQDs), the influence of defects is even more app...
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Interest has been growing in defects of halide perovskites in view of their intimate connection with key material optoelectronic properties. In perovskite quantum dots (PQDs), the influence of defects is even more apparent than in their bulk counterparts. By combining experiment and theory, we report herein a halide‐vacancy‐driven, ligand‐directed self‐assembly process of CsPbBr 3 PQDs. With the assistance of oleic acid and didodecyldimethylammonium sulfide, surface‐Br‐vacancy‐rich CsPbBr 3 PQDs self‐assemble into nanowires (NWs) that are 20–60 nm in width and several millimeters in length. The NWs exhibit a sharp photoluminescence profile (≈18 nm full‐width at‐half‐maximum) that peaks at 525 nm. Our findings provide insight into the defect‐correlated dynamics of PQDs and defect‐assisted fabrication of perovskite materials and devices.
This study presents the outcomes of the shared task competition BioCreative VII (Task 3) focusing on the extraction of medication names from a Twitter user's publicly available tweets (the user's 'timeline...
This study presents the outcomes of the shared task competition BioCreative VII (Task 3) focusing on the extraction of medication names from a Twitter user's publicly available tweets (the user's 'timeline'). In general, detecting health-related tweets is notoriously challenging for natural language processing tools. The main challenge, aside from the informality of the language used, is that people tweet about any and all topics, and most of their tweets are not related to health. Thus, finding those tweets in a user's timeline that mention specific health-related concepts such as medications requires addressing extreme imbalance. Task 3 called for detecting tweets in a user's timeline that mentions a medication name and, for each detected mention, extracting its span. The organizers made available a corpus consisting of 182 049 tweets publicly posted by 212 Twitter users with all medication mentions manually annotated. The corpus exhibits the natural distribution of positive tweets, with only 442 tweets (0.2%) mentioning a medication. This task was an opportunity for participants to evaluate methods that are robust to class imbalance beyond the simple lexical match. A total of 65 teams registered, and 16 teams submitted a system run. This study summarizes the corpus created by the organizers and the approaches taken by the participating teams for this challenge. The corpus is freely available at https://***/tasks/biocreative-vii/track-3/. The methods and the results of the competing systems are analyzed with a focus on the approaches taken for learning from class-imbalanced data.
Through judicious selection of glass composition, optical fibers with reduced susceptibility to deleterious light-matter interactions are achieved. The current state and future development of low nonlinearity fiber us...
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Thermal emission is the radiation of electromagnetic waves from hot objects. The promise of thermal-emission engineering for applications in energy harvesting, radiative cooling, and thermal camouflage has recently le...
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We propose an optical method of shining circularly polarized and spatially periodic laser fields to imprint superlattice structures in two-dimensional electronic systems. By changing the configuration of the optical f...
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We propose an optical method of shining circularly polarized and spatially periodic laser fields to imprint superlattice structures in two-dimensional electronic systems. By changing the configuration of the optical field, we synthesize various lattice structures with different spatial symmetry, periodicity, and strength. We find that the wide optical tunability allows one to tune different properties of the effective band structure, including Chern number, energy bandwidths, and band gaps. The in situ tunability of the superlattice gives rise to unique physics ranging from the topological transitions to the creation of the flat bands through the kagome superlattice, which can allow a realization of strongly correlated phenomena in Floquet systems. We consider the high-frequency regime where the electronic system can remain in the quasiequilibrium phase for an extended amount of time. The spatiotemporal reconfigurability of the present scheme opens up possibilities to control light-matter interaction to generate novel electronic states and optoelectronic devices.
We proposed a mechanism to generate giant anisotropic second harmonic nonlinear response via double resonance effect, achieved through band nesting via electronic bandstructure engineering. The ideal band setup would ...
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