213 research outputs found
Tuning catalytic selectivity in cascade reactions by light irradiation
Selectivity of cascade redox reactions: the reduction of nitrobenzene to azoxybenzene and then to azobenzene and the oxidation of benzyl alcohol to benzaldehyde and then to benzoic acid, is discovered to be tuneable via light irradiation over plasmonic gold photocatalysts. The representative photocatalyst of Au/CeO2 was characterized by TEM, EDX, UV–Vis and XPS to determine its morphology, elemental composition, photo absorptivity and oxidation state of gold. The catalytic test results demonstrate that the net contribution of light irradiation correlates with the ability of incident light to excite electrons and light absorption of catalysts. These findings may inspire peer researchers in developing new photocatalytic processes or in designing new photocatalysts for clean chemicals synthesis
Recent development of plasmon-mediated photocatalysts and their potential in selectivity regulation
Solar energy for chemical production with high product selectivity under ambient conditions has attracted considerable attention. The development of photocatalytic nanomaterials as antennas to absorb light irradiation plays a pivotal role. Hence, catalysis science and technology is indispensable in these transformations in order to achieve a high conversion and selectivity. This review mainly deals with the development and structure design of photocatalytic plasmonic nanomaterials in the synthesis of clean chemicals and highlights the mechanism of regulating catalytic selectivity
Physics-Driven Turbulence Image Restoration with Stochastic Refinement
Image distortion by atmospheric turbulence is a stochastic degradation, which
is a critical problem in long-range optical imaging systems. A number of
research has been conducted during the past decades, including model-based and
emerging deep-learning solutions with the help of synthetic data. Although fast
and physics-grounded simulation tools have been introduced to help the
deep-learning models adapt to real-world turbulence conditions recently, the
training of such models only relies on the synthetic data and ground truth
pairs. This paper proposes the Physics-integrated Restoration Network (PiRN) to
bring the physics-based simulator directly into the training process to help
the network to disentangle the stochasticity from the degradation and the
underlying image. Furthermore, to overcome the ``average effect" introduced by
deterministic models and the domain gap between the synthetic and real-world
degradation, we further introduce PiRN with Stochastic Refinement (PiRN-SR) to
boost its perceptual quality. Overall, our PiRN and PiRN-SR improve the
generalization to real-world unknown turbulence conditions and provide a
state-of-the-art restoration in both pixel-wise accuracy and perceptual
quality. Our codes are available at \url{https://github.com/VITA-Group/PiRN}.Comment: Accepted by ICCV 202
Scattering and Gathering for Spatially Varying Blurs
A spatially varying blur kernel is specified by an
input coordinate and an output coordinate
. For computational efficiency, we sometimes write
as a linear combination of spatially invariant basis
functions. The associated pixelwise coefficients, however, can be indexed by
either the input coordinate or the output coordinate. While appearing subtle,
the two indexing schemes will lead to two different forms of convolutions known
as scattering and gathering, respectively. We discuss the origin of the
operations. We discuss conditions under which the two operations are identical.
We show that scattering is more suitable for simulating how light propagates
and gathering is more suitable for image filtering such as denoising
Surface plasmon-enhanced zeolite catalysis under light irradiation and its correlation with molecular polarity of reactants
Enhanced catalytic performance of zeolites via the plasmonic effect of gold nanoparticles has been discovered to be closely correlated with the molecular polarity of reactants. The intensified polarised electrostatic field of Na+ in NaY plays a critical role in stretching the C=O bond of aldehydes to improve the reaction rate
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