892 research outputs found
Mode of action of quinoline antimalarial drugs in red blood cells infected by <i>Plasmodium falciparum</i> revealed <i>in vivo</i>
Exciton-driven change of phonon modes causes strong temperature dependent bandgap shift in nanoclusters
The fundamental bandgap E-g of a semiconductor-often determined by means of optical spectroscopy-represents its characteristic fingerprint and changes distinctively with temperature. Here, we demonstrate that in magic sized II-VI clusters containing only 26 atoms, a pronounced weakening of the bonds occurs upon optical excitation, which results in a strong exciton-driven shift of the phonon spectrum. As a consequence, a drastic increase of dE(g)/dT (up to a factor of 2) with respect to bulk material or nanocrystals of typical size is found. We are able to describe our experimental data with excellent quantitative agreement from first principles deriving the bandgap shift with temperature as the vibrational entropy contribution to the free energy difference between the ground and optically excited states. Our work demonstrates how in small nanoparticles, photons as the probe medium affect the bandgap-a fundamental semiconductor property. The bandgap of nanostructures usually follows the bulk value upon temperature change. Here, the authors find that in small nanocrystals a weakening of the bonds due to optical excitation causes a pronounced phonon shift, leading to a drastic enhancement of the bandgap's temperature dependence.
Spectrum-Guided Adversarial Disparity Learning
It has been a significant challenge to portray intraclass disparity precisely
in the area of activity recognition, as it requires a robust representation of
the correlation between subject-specific variation for each activity class. In
this work, we propose a novel end-to-end knowledge directed adversarial
learning framework, which portrays the class-conditioned intraclass disparity
using two competitive encoding distributions and learns the purified latent
codes by denoising learned disparity. Furthermore, the domain knowledge is
incorporated in an unsupervised manner to guide the optimization and further
boosts the performance. The experiments on four HAR benchmark datasets
demonstrate the robustness and generalization of our proposed methods over a
set of state-of-the-art. We further prove the effectiveness of automatic domain
knowledge incorporation in performance enhancement
Kondo effect in coupled quantum dots: a Non-crossing approximation study
The out-of-equilibrium transport properties of a double quantum dot system in
the Kondo regime are studied theoretically by means of a two-impurity Anderson
Hamiltonian with inter-impurity hopping. The Hamiltonian, formulated in
slave-boson language, is solved by means of a generalization of the
non-crossing approximation (NCA) to the present problem. We provide benchmark
calculations of the predictions of the NCA for the linear and nonlinear
transport properties of coupled quantum dots in the Kondo regime. We give a
series of predictions that can be observed experimentally in linear and
nonlinear transport measurements through coupled quantum dots. Importantly, it
is demonstrated that measurements of the differential conductance , for the appropriate values of voltages and inter-dot tunneling
couplings, can give a direct observation of the coherent superposition between
the many-body Kondo states of each dot. This coherence can be also detected in
the linear transport through the system: the curve linear conductance vs
temperature is non-monotonic, with a maximum at a temperature
characterizing quantum coherence between both Kondo states.Comment: 20 pages, 17 figure
FMAP: Functional Mapping and Analysis Pipeline for metagenomics and metatranscriptomics studies
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