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Online Action Detection Incorporating an Additional Action Classifier
No full textMost online action detection methods focus on solving a (K + 1) classification problem, where the additional category represents the ‘background’ class. However, training on the ‘background’ class and managing data imbalance are common challenges in online action detection. To address these issues, we propose a framework for online action detection by incorporating an additional pathway between the feature extractor and online action detection model. Specifically, we present one configuration that retains feature distinctions for fusion with the final decision from the Long Short-Term Transformer (LSTR), enhancing its performance in the (K + 1) classification. Experimental results show that the proposed method achieves an accuracy of 71.2% in mean Average Precision (mAP) on the Thumos14 dataset, outperforming the 69.5% achieved by the original LSTR method.補正完畢CH
Sr2HgGe2OS6: A Hg-Based Oxychalcogenide Infrared Nonlinear Optical Material Exhibiting Favorable Balance between a Large Band Gap and Strong Second Harmonic Generation Response
No full textCurrently, oxychalcogenides with mixed-anion groups that integrate the property advantages of oxides (wide optical band gap) and chalcogenides [strong second harmonic generation (SHG) response] through chemical substitution engineering have attracted widespread interest and are considered to be important candidates for infrared (IR) nonlinear optical (NLO) materials. Herein, the first Hg-based oxychalcogenide Sr2HgGe2OS6 with mixed anion [GeOS3] units has been successfully synthesized through a spontaneous crystallization method, which exhibits a favorable balance between the strong SHG response (0.7 × AgGaS2) and large optical band gap (2.9 eV). In addition, Sr2HgGe2OS6 shows high laser-induced damage threshold (LIDT, 2.1 × AgGaS2) as well as phase-matching (PM) performance. Theoretical calculations indicate that the Sr2HgGe2OS6 encompasses large birefringence of 0.128@2090 nm (3.3 × AgGaS2) and its SHG density mainly comes from [HgS4] tetrahedra and [GeOS3] units. This work not only demonstrates that Sr2HgGe2OS6 is a promising IR NLO material but also provides new ideas for the exploration of Hg-based oxychalcogenide IR NLO materials.補正完畢US
How gaming team participation fosters consumers’ social networks, communication and commitment
No full textOnline games are highly popular computer applications that generate enormous profits for companies that produce games. Online players actively participate and interact in gaming teams, but there is no study on how team participation leads to a commitment to gaming teams. Research that aims to fill this gap could elucidate practical solutions to strengthening the players' team commitment, contributing to the understanding of player behavior. Grounded in social capital theory and social exchange theory, in this paper a research model is developed, featuring an association between players' participation and players' team commitment. The data were gathered from 1352 online players, and structural equation modelling was employed as the data analysis technique. The results indicate that team participation is positively linked to network convergence and interdependence. They are, in turn, positively linked to social interaction and social presence, which significantly enhance the players' team commitment. We also find that, compared with social interaction, social presence has a stronger influence on such commitments. The research findings suggest that the game providers should encourage players to participate in gaming teams, thus strengthening the players’ team commitment.補正完畢NL
Determining quasi-equilibrium electron and hole distributions of plasmonic photocatalysts using photomodulated x-ray absorption spectroscopy
No full textMost photocatalytic and photovoltaic devices operate under broadband, constant illumination. Electron and hole dynamics in these devices, however, are usually measured by using ultrafast pulsed lasers in a narrow wavelength range. In this work, we use excited-state X-ray theory originally developed for transient X-ray experiments to study steady-state photomodulated X-ray spectra. We use this method to attempt to extract electron and hole distributions from spectra collected at a nontime-resolved synchrotron beamline. A set of plasmonic metal core–shell nanoparticles is designed as the control experiment because they can systematically isolate photothermal, hot electron, and thermalized electron–hole pairs in a TiO2 shell. Steady-state changes in the Ti L2,3 edge are measured with and without continuous-wave illumination of the nanoparticle’s localized surface plasmon resonance. The results suggest that within error the quasi-equilibrium carrier distribution can be determined even from relatively noisy data with mixed excited-state phenomena. Just as importantly, the theoretical analysis of noisy data is used to provide guidelines for the beamline development of photomodulated steady-state spectroscopy.補正完畢US
Enhancing supercapacitor performance with biomass-derived activated carbon interlinked CoS2 embedded graphitic carbon nitride
No full textThis work investigates the improved electrochemical performance of CoS2 on composites CoS2/AC and CoS2/AC/g-C3N4 that are prepared via hydrothermal method and the production of activated carbon is of bio-derived configuration. The structural, vibrational modes, and functional groups of the as synthesized nanostructures are confirmed through X-ray Diffraction (XRD), Raman, and FTIR analyses. The specific surface area of CoS2/AC and CoS2/AC/g-C3N4 is 54.3 m2g−1, and 41.3 m2g−1, respectively. X-ray Photoelectron Spectroscopy (XPS) reveals the charge state of Co2+ and high charge transfer between Co and C in CoS2/AC/g-C3N4 compared to CoS2/AC. Nanoprobe Projection X-ray microscopy (PXM) discloses distorted octahedral coordination of Co2+ and site-dependent charge transfer by Co in CoS2/AC in comparison with CoS2/AC/g-C3N4. Further, the CoS2/AC electrode demonstrates a high specific capacity of 984 Fg−1 in the three-electrode system. The high-performance CoS2/AC electrode produced a high-power density of 2042.21 W Kg−1 and an energy density of 28.36 Whkg−1 in an aqueous electrolyte. The integration of CoS2 nanoparticles into the CoS2/AC and CoS2/AC/g-C3N4 composite framework significantly contributes to the improvement of specific capacity and excellent cycle stability up to 5000 cycles. This improvement could be influenced by several factors, such as reduced ion transport distances, strengthened interfacial interactions, high surface area, distortion of octahedral coordination of Co2+, and spatial-dependent charge transfer by Co in CoS2/AC. The distinct characteristics in specific capacity and cycling stability is attributed to the incorporation of CoS2 nanoparticles within the CoS2/AC and CoS2/AC/g-C3N4 composites that cause the short transport distance of the ions, enhanced interfacial interaction, and further provide better structural stability of the CoS2/AC and CoS2/AC/g-C3N4 composite network.補正完畢NL
Electronic and atomic structural properties associated with enhanced photodegradation activity in Mo-doped TiO2 nanoparticles
No full textThe efficacy and structural evolution of Mo-doped titania nanoparticles (MTNPs) as advanced photocatalysts for degrading methyl blue (MB) are investigated by X-ray absorption spectroscopy (XAS). The 3 wt % MTNP, characterized by uniform size and anatase structure, exhibits higher efficiency. The spectral analyses unveiled structural variations in the TiO6 octahedral structure and revealed an active site of the distorted square pyramidal structure symmetry (C4v). The in situ XAS spectra illustrate that MTNPs, particularly at 3 wt % doping, effectively enhanced the hole carriers in Ti 3d orbitals with a charge transfer to Mo 4d orbitals and impeded electron–hole pair merging, significantly enhancing the photodegradation under light illumination. This study deepens our understanding of the crucial role of Mo doping in optimizing TiO2 nanoparticle performance for efficient environmental remediation, showcasing the potential of MTNPs as sustainable photocatalytic materials.補正完畢US
DNA-Anchored Single-Molecule Iron Phthalocyanine As an Efficient Electrocatalyst for Alkaline Fuel Cells
No full textMolecular catalysts have attracted significant attention because of their high activity, selectivity, and tunability. However, in heterogeneous catalysis, the uniform dispersion and immobilization of molecular catalysts on the supporting substrate remain a significant challenge due to their aggregation tendency. Here, we present a facile strategy to molecularly disperse and immobilize a series of macrocyclic metal complexes onto reduced graphene oxide (rGO) by using DNA as a mediator. The electroactive amounts of molecularly dispersed iron phthalocyanine (FePc) molecules are increased by ∼50 times greater than that of pristine FePc catalyst. As a result, the single-molecule catalyst demonstrates a notable power density (∼290 mW cm–2) in an H2/O2 alkaline polymer electrolyte fuel cell. Operando X-ray absorption spectroscopy experiments combined with density functional theory calculations reveal that the coordination interaction between FePc and DNA enables the molecular dispersion and immobilization of FePc on the surface of rGO, and consequently improves the activity by regulating the electronic structure of active centers. This study points out a facile strategy to tackle the fundamental challenges facing molecular catalysts in long-lasting energy conversion technologies.補正完畢US
Distributing circuits over heterogeneous, modular quantum computing network architectures
No full textWe consider a heterogeneous network of quantum computing modules, sparsely connected via Bell states. Operations across these connections constitute a computational bottleneck and they are likely to add more noise to the computation than operations performed within a module. We introduce several techniques for transforming a given quantum circuit into one implementable on such a network, minimising the number of Bell states required to do so. We extend previous works on circuit distribution to the case of heterogeneous networks. On the one hand, we extend the hypergraph approach of Andres-Martinez and Heunen (2019 Phys. Rev. A 100 032308) to arbitrary network topologies, and we propose the use of Steiner trees to detect and reuse common connections, further reducing the cost of entanglement sharing within the network. On the other hand, we extend the embedding techniques of Wu et al (2023 Quantum7 1196) to networks with more than two modules. We show that, with careful manipulation of trade-offs, these two new approaches can be combined into a single automated framework. Our proposal is implemented and benchmarked; the results confirm that our contributions make noticeable improvements upon the aforementioned works and complement their weaknesses.補正完畢US
Crystal structure-controlled synthesis of NiMoO4/NiO hierarchical microspheres for high-performance supercapacitors and photocatalysts
No full textGlobal environmental challenges and energy crises have driven researchers to develop multifunctional and highly efficient nanomaterials. This study presents dual-functional NiMoO4 (NMO)/NiO hierarchical microspheres that can serve as supercapacitors and photocatalysts prepared using a microwave-assisted hydrothermal method. The α- and β-phase contents of NMO can be regulated by controlling the post-annealing temperature and pH value of the precursor solution. The as-prepared NMO/NiO nanocomposites exhibited dual Faradaic redox reactions attributed to NMO and NiO, leading to remarkable supercapacitor performance. In addition, the constructed heterojunction between NMO and NiO also improved charge separation, leading to excellent photocatalytic capability. Based on the results, NMO with a higher β-phase content showed better supercapacitive and photocatalytic performance owing to its higher conductivity. The optimal NMO/NiO composite displayed a specific capacitance of 943 F g−1 at 1 A/g and excellent cycling stability, with 83.1 % retention at 5 A/g after 4000 cycles. Additionally, it demonstrated an outstanding photocatalytic capability for the degradation of methylene blue (MB), achieving a rate constant of (0.0113 min−1).補正完畢NL
Construction of hierarchical flower-like BiVO4/Bi2WO6 microspheres with enhanced electrochemical performance for supercapacitors and lithium ion batteries
No full textCreation of three-dimensional (3D) nanostructures is an intriguing method for enhancing the electrochemical properties of energy storage materials. In this study, we have prepared 3D BiVO4/Bi2WO6 (BVO/BWO) flower-like microsphere assembled by 0D BVO nanoparticles and 2D BWO nanosheets via a facile microwave-assisted hydrothermal method. The decoration of BVO nanoparticles onto BWO nanosheets can prevent the BWO nanosheets from restacking in a disorganized manner, thereby facilitating the formation of mesoporous BVO/BWO hierarchical microspheres. Compared with the BVO and BWO single components, the assembled BVO/BWO microspheres show higher surface area, improved electron/ion migration and better structural stability. These characteristics contribute to a rapid and reversible redox process in energy storage applications. The mesoporous BVO/BWO hierarchical microspheres applied for supercapacitor demonstrate a high specific capacitance of 616.8 F/g at 1 A/g and an excellent cycling stability with 87.0 % retention at 4 A/g after 4000 cycles. Additionally, the BVO/BWO composites used as anode materials in lithium ion batteries (LIBs) also deliver a higher capacity of 635.0 mAh/g at 100 mA/g with improved cycling stability compared with the other two samples.補正完畢NL