1,538 research outputs found
Chemically Exfoliated Graphene Nanosheets for Flexible Electrode Applications
Graphene oxide (GO), produced by oxidation of graphite powder and exfoliation, is intensively utilized in electrodes, templates for hybrid materials, interfacial modifiers, three-dimensional structures, and so on, with its performance as an electrode material being determined by its chemical and structural states. This chapter describes the fabrication method of GO nanosheets from graphite oxide powder and their stable dispersion after reduction and applications in devices. Rheologically driven exfoliation and unusual acoustic cavitation methods were applied to produce large and less defective GO nanosheets. As a dispersion strategy of reduced GO (RGO) in solution, TiO2 precursor, cation-Ï€ interaction, silanol groups were introduced. Moreover, supramolecular chemistry, for example, quadruple hydrogen bonding moieties, was applied to solve the dispersion of highly concentrated RGO pastes. As potential applications of GO and RGO, we described GO as a p-type dopant and interfacial modifier as well as energy storage electrodes, IR sensors, and emitters. The judicious use of chemically exfoliated graphene can open new applications as a flexible electrode
Development of deformation-tunable quadrupolar microcavity
We have developed a technique for realizing a two-dimensional quadrupolar
microcavity with its deformation variable from 0% to 20% continuously. We
employed a microjet ejected from a noncircular orifice in order to generate a
stationary column with modulated quadrupolar deformation in its cross section.
Wavelength red shifts of low-order cavity modes due to shape deformation were
measured and were found to be in good agreement with the wave calculation for
the same deformation, indicating the observed deformation is quadrupolar in
nature.Comment: 7 pages, 6 figures, intended for Rev. Sci. Instu
Chaos-assisted nonresonant optical pumping of quadrupole-deformed microlasers
Efficient nonresonant optical pumping of a high-Q scar mode in a
two-dimensional quadrupole-deformed microlaser has been demonstrated based on
ray and wave chaos. Three-fold enhancement in the lasing power was achieved at
a properly chosen pumping angle. The experimental result is consistent with ray
tracing and wave overlap integral calculations.Comment: 3 pages, 5 figure
Grouping-matrix based Graph Pooling with Adaptive Number of Clusters
Graph pooling is a crucial operation for encoding hierarchical structures
within graphs. Most existing graph pooling approaches formulate the problem as
a node clustering task which effectively captures the graph topology.
Conventional methods ask users to specify an appropriate number of clusters as
a hyperparameter, then assume that all input graphs share the same number of
clusters. In inductive settings where the number of clusters can vary, however,
the model should be able to represent this variation in its pooling layers in
order to learn suitable clusters. Thus we propose GMPool, a novel
differentiable graph pooling architecture that automatically determines the
appropriate number of clusters based on the input data. The main intuition
involves a grouping matrix defined as a quadratic form of the pooling operator,
which induces use of binary classification probabilities of pairwise
combinations of nodes. GMPool obtains the pooling operator by first computing
the grouping matrix, then decomposing it. Extensive evaluations on molecular
property prediction tasks demonstrate that our method outperforms conventional
methods.Comment: 10 pages, 3 figure
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