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Weichao Kong

Bio: Weichao Kong is an academic researcher from Nankai University. The author has contributed to research in topics: Materials science & Catalysis. The author has an hindex of 1, co-authored 3 publications receiving 3 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article , an interfacial engineering strategy that is capable of simultaneously regulating nanoscale structure, electronic structure, and interfacial structure of Mo2N quantum dots decorated on conductive N-doped graphene via codoping single-atom Al and O (denoted as AlO@Mo2N•NrGO) is reported.
Abstract: The development of low‐cost, high‐efficiency, and stable electrocatalysts for hydrogen evolution reaction (HER) under alkaline conditions is a key challenge in water electrolysis. Here, an interfacial engineering strategy that is capable of simultaneously regulating nanoscale structure, electronic structure, and interfacial structure of Mo2N quantum dots decorated on conductive N‐doped graphene via codoping single‐atom Al and O (denoted as AlO@Mo2N‐NrGO) is reported. The conversion of Anderson polyoxometalates anion cluster ([AlMo6O24H6]3−, denoted as AlMo6) to Mo2N quantum dots not only result in the generation of more exposed active sites but also in situ codoping atomically dispersed Al and O, that can fine‐tune the electronic structure of Mo2N. It is also identified that the surface reconstruction of AlOH hydrates in AlO@Mo2N quantum dots plays an essential role in enhancing hydrophilicity and lowering the energy barriers for water dissociation and hydrogen desorption, resulting in a remarkable alkaline HER performance, even better than the commercial 20% Pt/C. Moreover, the strong interfacial interaction (MoN bonds) between AlO@Mo2N and N‐doped graphene can significantly improve electron transfer efficiency and interfacial stability. As a result, outstanding stability over 300 h at a current density higher than 100 mA cm−2 is achieved, demonstrating great potential for the practical application of this catalyst.

6 citations

Journal ArticleDOI
TL;DR: A bidirectional cascaded deep neural network with a pretrained autoencoder for rapid design of dielectric metasurfaces in the range of 450 nm to 850 nm and the mechanism behind the model is revealed in a visualization way.
Abstract: Metasurfaces composed of meta-atoms provide promising platforms for manipulating amplitude, phase, and polarization of light. However, the traditional design methods of metasurfaces are time consuming and laborious. Here, we propose a bidirectional cascaded deep neural network with a pretrained autoencoder for rapid design of dielectric metasurfaces in the range of 450 nm to 850 nm. The forward model realizes a prediction of amplitude and phase responses with a mean absolute error of 0.03. Meanwhile, the backward model can retrieve patterns of meta-atoms in an inverse-design manner. The availability of this model is demonstrated by database establishment, model evaluation, and generalization testing. Furthermore, we try to reveal the mechanism behind the model in a visualization way. The proposed approach is beneficial to reduce the cost of computation burden and improve nanophotonic design efficiency for solving electromagnetic on-demand design issues automatically.

6 citations

Journal ArticleDOI
TL;DR: In this article , the promising alkaline exchange membrane fuel cells (AEMFCs) are subject to the sluggish kinetics of anodic hydrogen oxidation reaction (HOR) and balancing the adsorption/desorption ability toward H* and OH* is considered.
Abstract: The promising alkaline exchange membrane fuel cells (AEMFCs) are subject to the sluggish kinetics of anodic hydrogen oxidation reaction (HOR). Balancing the adsorption/desorption ability toward H* and OH* is considered...

3 citations

Journal ArticleDOI
TL;DR: An all-dielectric theta modulation meta-surface with a new encoding method, which separates red, green, blue, and achromatic spatial channels on the focal plane, which may have an important application in compact multispectral photography only with one detector.
Abstract: The traditional theta modulator encodes input information by superimposing Ronchi sub-gratings, which is extremely easy to cause spatial channel overlap that results in bands mixing. In this case, we present an all-dielectric theta modulation meta-surface with a new encoding method, which separates red, green, blue, and achromatic spatial channels on the focal plane. The meta-surface ensures that the positions of focal points are relatively consistent while focusing energy into the sub-wavelength regions. Our study offers a way to facilitate device miniaturization and system integration, which may have an important application in compact multispectral photography only with one detector.

3 citations

Journal ArticleDOI
TL;DR: In this article, a dual-helical dielectric cone was proposed to generate the dual-vortex beam, which can be used to manipulate and arrange the nano-microparticles in 3D space.
Abstract: Optical vortex is of great value in optical trapping, manipulating, and arranging. Here, we propose a dual-helical dielectric cone to generate a dual-vortex beam which can be used to manipulate and arrange dielectric microparticles in three-dimensional space. With the finite-difference time-domain simulation, we calculate the electromagnetic field intensity distribution, phase, and Poynting vector during the propagation of the dual-vortex beam, the optical force and optical torque on the microparticles in the range of dual-vortex beam is also considered. In the experiment, we use the phase mask projected on spatial light modulator to generate a dual-vortex beam, which can trap, manipulate, and arrange the fluorescent microparticles to a specific and stable shape, which is consistent with the results of our simulation calculations. The dual-vortex beam generated by the dual-helical dielectric cone provides a feasible method three-dimensional optical manipulation, which is significant in biophotonical researches.

3 citations


Cited by
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Journal ArticleDOI
TL;DR: The reflection characteristics of a thin and dual-band metasurface are examined in the microwave frequency regime and it has been estimated that the surface has the additional ability to convert linearly polarized waves to circularly polarized waves at several distinct frequencies.
Abstract: The manipulation of polarization state of electromagnetic waves is of great importance in many practical applications. In this paper, the reflection characteristics of a thin and dual-band metasurface are examined in the microwave frequency regime. The metasurface consists of a 22 × 22 element array of periodic unit cells. The geometry of the unit cell consists of three layers, including a 45° inclined dipole shape metal patch on top, which is backed by a 1.6 mm thick FR-4 substrate in the middle, and a fully reflective metallic mirror at the bottom. The proposed surface is exposed to horizontally (x) or vertically (y) polarized plane waves and the co and cross polarization reflection coefficients of the reflected waves are investigated experimentally in the 6-26 GHz frequency range. The metasurface is designed to convert incident waves of known polarization state (horizontal or vertical) to orthogonal polarization state (vertical and horizontal) in two distinct frequency bands, i.e. 7.1-8 GHz and 13.3-25.8 GHz. In these two frequency bands the simulated and experimental results are in good agreement. The polarization conversion ratio (PCR) of the surface is greater than 95% in the targeted frequency bands. A detailed parametric analysis of the metasurface is also discussed in this work and it has been estimated that the surface has the additional ability to convert linearly polarized waves to circularly polarized waves at several distinct frequencies. The proposed metasurface can be utilized in sensor applications, stealth technology, electromagnetic measurements, and antennas design.

25 citations

Journal ArticleDOI
TL;DR: The presented RFODL-MGEC model aims to improve classification performance by selecting appropriate features and uses a novel red fox optimizer (RFO)-based feature selection approach for deriving an optimal subset of features.
Abstract: Microarray data examination is a relatively new technology that intends to determine the proper treatment for various diseases and a precise medical diagnosis by analyzing a massive number of genes in various experimental conditions. The conventional data classification techniques suffer from overfitting and the high dimensionality of gene expression data. Therefore, the feature (gene) selection approach plays a vital role in handling a high dimensionality of data. Data science concepts can be widely employed in several data classification problems, and they identify different class labels. In this aspect, we developed a novel red fox optimizer with deep-learning-enabled microarray gene expression classification (RFODL-MGEC) model. The presented RFODL-MGEC model aims to improve classification performance by selecting appropriate features. The RFODL-MGEC model uses a novel red fox optimizer (RFO)-based feature selection approach for deriving an optimal subset of features. Moreover, the RFODL-MGEC model involves a bidirectional cascaded deep neural network (BCDNN) for data classification. The parameters involved in the BCDNN technique were tuned using the chaos game optimization (CGO) algorithm. Comprehensive experiments on benchmark datasets indicated that the RFODL-MGEC model accomplished superior results for subtype classifications. Therefore, the RFODL-MGEC model was found to be effective for the identification of various classes for high-dimensional and small-scale microarray data.

10 citations

Journal ArticleDOI
TL;DR: In this article , an interfacial engineering strategy that is capable of simultaneously regulating nanoscale structure, electronic structure, and interfacial structure of Mo2N quantum dots decorated on conductive N-doped graphene via codoping single-atom Al and O (denoted as AlO@Mo2N•NrGO) is reported.
Abstract: The development of low‐cost, high‐efficiency, and stable electrocatalysts for hydrogen evolution reaction (HER) under alkaline conditions is a key challenge in water electrolysis. Here, an interfacial engineering strategy that is capable of simultaneously regulating nanoscale structure, electronic structure, and interfacial structure of Mo2N quantum dots decorated on conductive N‐doped graphene via codoping single‐atom Al and O (denoted as AlO@Mo2N‐NrGO) is reported. The conversion of Anderson polyoxometalates anion cluster ([AlMo6O24H6]3−, denoted as AlMo6) to Mo2N quantum dots not only result in the generation of more exposed active sites but also in situ codoping atomically dispersed Al and O, that can fine‐tune the electronic structure of Mo2N. It is also identified that the surface reconstruction of AlOH hydrates in AlO@Mo2N quantum dots plays an essential role in enhancing hydrophilicity and lowering the energy barriers for water dissociation and hydrogen desorption, resulting in a remarkable alkaline HER performance, even better than the commercial 20% Pt/C. Moreover, the strong interfacial interaction (MoN bonds) between AlO@Mo2N and N‐doped graphene can significantly improve electron transfer efficiency and interfacial stability. As a result, outstanding stability over 300 h at a current density higher than 100 mA cm−2 is achieved, demonstrating great potential for the practical application of this catalyst.

6 citations

Patent
31 Oct 2012
TL;DR: In this article, systems and methods for multispectral imaging are disclosed, which can include a near infrared (NIR) imaging sensor and a visible imaging sensor, and they can be implemented to improve alignment between the NIR and visible images.
Abstract: Systems and methods for multispectral imaging are disclosed. The multispectral imaging system can include a near infrared (NIR) imaging sensor and a visible imaging sensor. The disclosed systems and methods can be implemented to improve alignment between the NIR and visible images. Once the NIR and visible images are aligned, various types of multispectral processing techniques can be performed on the aligned images.

4 citations

Journal ArticleDOI
TL;DR: In this article , a review of hydrogen catalysts and their regulation strategies is presented, including geometry, composition, atom-doping, oxyphilic site and substrate engineerings.
Abstract: Hydrogen oxidation reaction (HOR) is an important semi‐cell reaction in the renewable energy conversion technology such as fuel cells. However, due to the slow reaction rate, the development of highly active catalysts remains a major challenge in alkaline fuel cells. Based on fundamental understanding of the sluggish kinetics toward the reaction mechanism in alkaline electrolytes, noble and non‐noble metal catalysts and their regulation strategies including geometry, composition, atom‐doping, oxyphilic site and substrate engineerings are analyzed and summarized in this review to seek for the possible breakthrough toward HOR catalytic performance enhancement. Eventually, challenges and opportunities faced by alkaline HOR, and potential future research trends are proposed. This review not only deepens the understanding of the hydrogen electrocatalysis mechanism, but also provides guidelines for the rational design of advanced HOR catalysts.

3 citations