Electrocatalytic water splitting for hydrogen production is an appealing strategy to reduce carbon emissions and generate renewable *** promising process,however,is limited by its sluggish reaction kinetics and high-c...
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Electrocatalytic water splitting for hydrogen production is an appealing strategy to reduce carbon emissions and generate renewable *** promising process,however,is limited by its sluggish reaction kinetics and high-cost *** two-dimensional(2D)transition metal dichalcogenides(TMDCs)have presented great potential as electrocatalytic materials due to their tunable bandgaps,abundant defective active sites,and good chemical ***,phase engineering,defect engineering and interface engineering have been adopted to manipulate the electronic structure of TMDCs for boosting their exceptional catalytic ***,it is essential to clarify the local structure of catalytically active sites of TMDCs and their structural evolution in catalytic reactions using atomic resolution electron microscopy and the booming in situ technologies,which is beneficial for exploring the underlying reaction *** this review,the growth regulation,characterization,particularly atomic configurations of active sites in TMDCs are *** significant role of electron microscopy in the understanding of the growth mechanism,the controlled synthesis and functional optimization of 2D TMDCs are *** review will shed light on the design and synthesis of novel electrocatalysts with high performance,as well as prompt the application of advanced electron microscopy in the research of materials science.
The slow phase transformation of microalloyed dual phase steel makes the nonuniform stress and temperature fields during the post rolling cooling process have a significant impact on the phase transformation *** the r...
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The slow phase transformation of microalloyed dual phase steel makes the nonuniform stress and temperature fields during the post rolling cooling process have a significant impact on the phase transformation *** the relatively slow phase transformation of DP780 steel within the microalloyed dual phase steel series,the influence of stress on the phase transformation behavior of DP780 steel was *** quantify the nonuniform thermal and stress conditions in the steel coil,a thermo-mechanical coupled finite element model of the hot-rolled strip cooling process was *** on the simulation data,DP780 steel was chosen as the research material,and Gleeble 3500 thermal simulation equipment was used for experimental *** thermal expansion curves were analyzed through regression to establish the dynamic model of DP780 steel phase transformation under ***,metallographic analysis was conducted to determine phase transformation type and grain size of DP780 *** results confirmed that the stress promotes the occurrence of semi-diffusion-type bainite ***,an appropriate level of stress facilitates the growth of bainitic grains,while the increased stress inhibits the growth of ferritic grains.
Regulating the local coordination of Fe active center can further improve the oxygen reduction reaction(ORR)performance of Fe-N-C catalyst to meet the practical application requirements of zinc-air batteries(ZABs).Her...
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Regulating the local coordination of Fe active center can further improve the oxygen reduction reaction(ORR)performance of Fe-N-C catalyst to meet the practical application requirements of zinc-air batteries(ZABs).Herein,carbon vacancies modified hollow porous catalysts(C-FeZ8@PDA-950)are constructed by microenvironment modulation,achieving the efficient utilization of active sites and optimization of elec-tronic *** functional theory(DFT)calculations confirm that the defective-edge Fe-N_(4) sites can weaken the adsorption free energy of OH^(∗),and hinder the dissolution of Fe center,significantly accel-erating the ORR process for *** rechargeable liquid ZABs equipped with C-FeZ8@PDA-950 display high specific capacity(819.95 mAh g Zn^(−1))and excellent long-cycling life(over 500 h).Furthermore,the relevant flexible all-solid-state ZABs also display outstanding folding performance under various bending *** work will provide insights into optimizing the electronic structure to improve electrocatalytic performance in the energy conversion and storage area.
Light-drive hydrogen production using titanium-based perovskite is one sustainable way to reduce current reliance on fossil fuels,but its wide applications are still limited by high electron−hole recombination and slu...
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Light-drive hydrogen production using titanium-based perovskite is one sustainable way to reduce current reliance on fossil fuels,but its wide applications are still limited by high electron−hole recombination and sluggish surface ***,the developments for low-cost and highly efficient co-catalysts remain *** by natural[NiFe]-hydrogenase active center structure,a hydrogenase-mimic,NiCo_(2)S_(4) nanozyme was synthesized,and subsequently decorated onto the CaTiO_(3) to catalyze the hydrogen evolution reaction(HER).Among the following test,CaTiO_(3)with a 15%loading of NiCo_(2)S_(4) nanozyme exhibited the highest HER rate of 307.76μmol·g^(–1)·h^(–1),which is 60 times higher than that of the CaTiO_(3) *** results reveal that NiCo_(2)S_(4) not only significantly increased the charge separation efficiency of the photogenerated carriers,but also substantively lowered the HER activation *** studies show that NiCo_(2)S_(4) readily splits H_(2)O by forming the Ni(OH)-Co intermediate and only Ni in the bimetallic center alters the oxidation state during the HER process in a manner analogous to the[NiFe]-*** contrast to the often-expensive synthetic catalysts that rely on rare elements such as ruthenium and platinum,this study shows a promising way to develop the nature-inspired cocatalysts to enhance the photocatalysts’HER performance.
InP quantum dots(QDs)are promising heavy-metal-free materials for next-generation solid-state lighting,covering from visible to near-infrared(NIR)*** with the rapid development of visible InP QDs,the synthesis of high...
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InP quantum dots(QDs)are promising heavy-metal-free materials for next-generation solid-state lighting,covering from visible to near-infrared(NIR)*** with the rapid development of visible InP QDs,the synthesis of high-performance NIR InP QDs remains to be *** this work,we report a simple one-pot synthesis of NIR InP QDs by controlling the Cu doping and designing a multishell *** replacing the conventional highly reactive phosphorus precursor with a slightly less reactive and low-cost ammonia phosphorus precursor,the nucleation process is effectively regulated for efficient Cu *** addition,the epitaxial growth of the ZnSe/ZnS shell further improves the stability and optical properties of InP ***,the synthesized Cu:InP/ZnSe/ZnS QDs have a photoluminescence quantum yield of 70%centered at 833 *** NIR InP lightemitting diodes exhibit a maximum radiance of 3.1 W·sr^(-1)·m^(-2)and a peak external quantum efficiency of 2.71%centered at 864 nm.
Adopting high-voltage Ni-rich cathodes in halide and sulfide-based all-solid-state lithium batteries(ASSLBs)holds great promise for breaking through the 400 Wh kg^(-1)***,both cell configurations are confronted with i...
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Adopting high-voltage Ni-rich cathodes in halide and sulfide-based all-solid-state lithium batteries(ASSLBs)holds great promise for breaking through the 400 Wh kg^(-1)***,both cell configurations are confronted with intricate interfacial challenges in high-voltage regines(>4.5 V),resulting in inadequate cathode utilization and premature cell ***,contrary to previous studies,coupled with LiNi_(0.85)Co_(0.1)Mn_(0.05)O_(2)cathodes,typical halide(Li_(2)ZrCl_(6))-based cells at 4.5 V feature unlimited interfacial degradation and poor long cycle stability,while typical sulfide(Li_(6)PS_(5)Cl)-based cells feature self-limited interfacial degradation and poor initial cycle ***,this work addresses the high-voltage limitations of Li_(2)ZrCl_(6)and Li_(6)PS_(5)Cl catholyte-based cells by manipulating electrode mass fraction and tailoring interfacial composition,thereby effectively improving interfacial charge-transfer kinetics and(electro)chemical stability within *** appropriate interface design,both optimized cells at 4.5 V demonstrate remarkably increased initial discharge capacities(>195 mA h g^(-1)at0.1 C),improved cycle stabilities(>80%after 600 cycles at 0.5 C),and enhanced rate performances(>115 mA h g^(-1)at 1.0 C).This work deepens our understanding of high-voltage applications for halide/sulfide electrolytes and provides generalized interfacial design strategies for advancing high-voltage ASSLBs.
Recent theoretical verification of self-similar and dissipative pure-quartic solitons(PQSs)emphasized the similarity between PQS lasers and conventional fiber lasers,but the unique equilibrium mechanism hinders the fo...
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Recent theoretical verification of self-similar and dissipative pure-quartic solitons(PQSs)emphasized the similarity between PQS lasers and conventional fiber lasers,but the unique equilibrium mechanism hinders the formation of PQS molecules in normal fourth-order dispersion(FOD)*** this paper,we investigated the effect of filters on shaping PQSs in normal FOD based on a passively mode-locked fiber laser model.A bandpass filter eliminates the time pedestal of dissipative PQSs,thus realizing a multi-pulsing *** the filter bandwidth is appropriate,the effective spectral filtering effect can lower the pulse splitting threshold and enable the coherent restoration from chaotic PQSs to PQS ***,changing the central wavelength of the filter can generate PQSs and PQS molecules with asymmetric intensity *** results are important guides for the manipulation of PQSs and the construction of high repetition-frequency fiber lasers.
Taking underwater robots project as an example, this paper discusses the innovation of the teaching mode of engineering drawing courses under the guidance of a project. The traditional engineering drawing course often...
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The structure of the oxide film on FGH96 alloy powders significantly influences the mechanical properties of *** this study,FGH96 alloy powders with various oxygen contents were investigated using high-resolution tran...
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The structure of the oxide film on FGH96 alloy powders significantly influences the mechanical properties of *** this study,FGH96 alloy powders with various oxygen contents were investigated using high-resolution transmission electron microscopy and atomic probe technology to elucidate the structure evolution of the oxide *** dispersive spectrometer analysis revealed the presence of two distinct components in the oxide film of the alloy powders:amorphous oxide layer covering the γ matrix and amorphous oxide particles above the *** alloying elements within the oxide layer showed a laminated distribution,with Ni,Co,Cr,and Al/Ti,which was attributed to the decreasing oxygen equilibrium pressure as oxygen diffused from the surface into the γ *** the other hand,Ti enrichment was observed in the oxide particles caused by the oxidation and decomposition of the carbide *** analysis of the oxide film with oxygen contents of 140,280,and 340 ppm showed similar element distributions,while the thickness of the oxide film varies approximately at 9,14,and 30 nm,*** findings provide valuable insights into the structural analysis of the oxide film on FGH96 alloy powders.
In high-risk industrial environments like nuclear power plants, precise defect identification and localization are essential for maintaining production stability and safety. However, the complexity of such a harsh env...
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In high-risk industrial environments like nuclear power plants, precise defect identification and localization are essential for maintaining production stability and safety. However, the complexity of such a harsh environment leads to significant variations in the shape and size of the defects. To address this challenge, we propose the multivariate time series segmentation network(MSSN), which adopts a multiscale convolutional network with multi-stage and depth-separable convolutions for efficient feature extraction through variable-length templates. To tackle the classification difficulty caused by structural signal variance, MSSN employs logarithmic normalization to adjust instance distributions. Furthermore, it integrates classification with smoothing loss functions to accurately identify defect segments amid similar structural and defect signal subsequences. Our algorithm evaluated on both the Mackey-Glass dataset and industrial dataset achieves over 95% localization and demonstrates the capture capability on the synthetic dataset. In a nuclear plant's heat transfer tube dataset, it captures 90% of defect instances with75% middle localization F1 score.
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