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Porous TiFe_(2) intermetallic compound fabricated via elemental powder reactive synthesis

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 764-772页

作者： Qian Zhao Zhenli He Yuehui He Yue Qiu Zhonghe Wang Yao Jiang State Key laboratory of Powder Metallurgy Powder Metallurgy Research InstituteCentral South UniversityChangsha 410083China

Porous intermetallics show potential in the field of filtration and separation as well as in the field of ***,porous Ti Fe2intermetallics were fabricated by the reactive synthesis of elemental *** phase transformation and pore formation of porous TiFe2intermetallics were investigated,and its corrosion behavior and hydrogen evolution reaction(HER)performance in alkali solution were *** TiFe2intermetallics with porosity in the range of 34.4%-56.4%were synthesized by the diffusion reaction of Ti and Fe elements,and the pore formation of porous TiFe2intermetallic compound is the result of a combination of the bridging effect and the Kirkendall *** porous TiFe2samples exhibit better corrosion resistance compared with porous 316L stainless steel,which is related to the formation of uniform nanosheets on the surface that hinder further corrosion,and porous TiFe2electrode shows the overpotential of 220.6 and 295.6 mV at 10 and 100 mA·cm-2,suggesting a good catalytic *** synthesized porous Fe-based intermetallic has a controllable pore structure as well as excellent corrosion resistance,showing its potential in the field of filtration and separation.

关键词： TiFe2 intermetallic compound porous materials reactive synthesis corrosion behavior hydrogen evolution reaction

KeyEE:Enhancing Low-Resource Generative Event Extraction with Auxiliary Keyword Sub-Prompt

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Big Data Mining and Analytics 2024年第2期7卷 547-560页

作者： Junwen Duan Xincheng Liao Ying An Jianxin Wang Hunan Key laboratory of Bioinformatics School of Computer Science and EngineeringCentral South UniversityChangsha 410083China Big Data institute Central South UniversityChangsha 410083China

Event Extraction(EE)is a key task in information extraction,which requires high-quality annotated data that are often costly to *** classification-based methods suffer from low-resource scenarios due to the lack of label semantics and fine-grained *** recent approaches have endeavored to address EE through a more data-efficient generative process,they often overlook event keywords,which are vital for *** tackle these challenges,we introduce KeyEE,a multi-prompt learning strategy that improves low-resource event extraction by Event Keywords Extraction(EKE).We suggest employing an auxiliary EKE sub-prompt and concurrently training both EE and EKE with a shared pre-trained language *** the auxiliary sub-prompt,KeyEE learns event keywords knowledge implicitly,thereby reducing the dependence on annotated ***,we investigate and analyze various EKE sub-prompt strategies to encourage further research in this *** experiments on benchmark datasets ACE2005 and ERE show that KeyEE achieves significant improvement in low-resource settings and sets new state-of-the-art results.

关键词： natural language processing Event Extraction(EE) Multi-Prompt Learning(MPL) low-resource

Complexity growth in a holographic QCD model

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Chinese Physics C 2024年第3期48卷 142-147页

作者：常文彬侯德富 institute of Particle Physics and Key laboratory of Quark and Lepton Physics(MOS) Central China Normal UniversityWuhan 430079China

In this study,we utilize the complexity-action duality to study the evolution of complexity in a holographic QCD model at finite temperature and chemical *** inserting a fundamental string as a probe,we investigated the properties of complexity growth in this Einstein-Maxwell-scalar gravity system,which is affected by the string velocity,chemical potential,and *** results show that the complexity growth is maximized when the probe string is stationary,and it decreases as the velocity of the string *** the string approaches relativistic velocities,the complexity growth always increases monotonically with respect to the chemical ***,we find that the complexity growth can be used to identify phase transitions and crossovers in the model.

关键词： AdS/CFT holographic QCD model complexity growth

Bridging buried interface enable 24.67%-efficiency doctor-bladed perovskite solar cells in ambient condition

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Nano Research 2024年第9期17卷 8068-8076页

作者： Jianhui Chang Erming Feng Xiangxiang Feng Hengyue Li Yang Ding Caoyu Long Siyuan Lu Haixia Zhu Wen Deng Jiayan Shi Yingguo Yang Si Xiao Yongbo Yuan Junliang Yang Hunan Key laboratory for Super-microstructure and Ultrafast Process School of PhysicsCentral South UniversityChangsha 410083China Hunan Key laboratory of Nanophotonics and Devices School of PhysicsCentral South UniversityChangsha 410083China Textile and Fashion Collage Hunan Institute of EngineeringXiangtan 411101China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China State Key laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

Scalable deposition of high-efficiency perovskite solar cells(PSCs)is critical to accelerating their commercial ***,a significant number of defects are distributed at the buried interface of perovskite film fabricated by scalable deposition,exhibiting much negative influence on the efficiency and stability of ***,2-(N-morpholino)ethanesulfonic acid potassium salt(MESK)is incorporated as the bridging layer between the tin oxide(SnO_(2))electron transport layer(ETL)and the perovskite film deposited via scalable two-step doctor *** experiment and simulation results demonstrate that MESK can passivate the trap states of Sn suspension bonds,thereby enhancing the charge extraction and transport of the SnO_(2)***,the strong interaction with uncoordinated Pb ions can modulate the crystal growth and crystallographic orientation of perovskite film and passivate buried *** employing MESK interface bridging,PSCs fabricated via scalable doctor blading in ambient condition achieve a power conversion efficiency(PCE)of 24.67%,which is one of the highest PCEs for doctor-bladed PSCs,and PSC modules with an active area of 11.35 cm^(2)achieve a PCE of 19.45%.Furthermore,PSCs exhibit excellent long-term stability,and the unpackaged target device with a storage of 1680 h in ambient condition(25℃and humidity of 30%relative humidity(RH))can maintain more than 90%of the initial *** research provides a strategy for constructing a high-performance interface bridge between SnO_(2)ETL and perovskite film,and achieving efficient and stable large-area PSCs and modules fabricated via scalable doctor-blading process in ambient condition.

关键词： perovskite solar cells doctor blading buried interface defect passivation orientation regulation

Unveiling strain-enhanced moiréexciton localization in twisted van der Waals homostructures

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Nano Research 2024年第4期17卷 3245-3252页

作者： Henry Rui He Haihong Zheng Biao Wu Shaofei Li Junnan Ding Zongwen Liu Jian-Tao Wang Anlian Pan Yanping Liu institute of Quantum Physics School of PhysicsCentral South UniversityChangsha 410083China State Key laboratory of Precision Manufacturing for Extreme Service Performance Central South UniversityChangsha 410083China School of Chemical and Biomolecular Engineering The University of SydneyNSW 2006Australia Beijing National laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China College of Materials Science and Engineering Hunan UniversityChangsha 410082China State Key laboratory of High-Performance Complex Manufacturing Central South UniversityChangsha 410083China Shenzhen Research institute of central South University Shenzhen 51800China

Moirésuperlattices,arising from the controlled twisting of van der Waals homostructures at specific angles,have emerged as a promising platform for quantum emission ***,the manipulation of strain provides a versatile strategy to finely adjust electronic band structures,enhance exciton luminescence efficiency,and establish a robust foundation for two-dimensional quantum light ***,the intricate interplay between strain and moirépotential remains partially ***,we introduce a meticulously designed fusion of strain engineering and the twisted 2L-WSe_(2)/2L-WSe_(2) homobilayers,resulting in the precise localization of moiré*** low-temperature photoluminescence spectroscopy,we unveil the emergence of highly localized moiré-enhanced emission,characterized by the presence of multiple distinct emission ***,our investigation demonstrates the effective regulation of moirépotential depths through strain engineering,with the potential depths of strained and unstrained regions differing by 91%.By combining both experimental and theoretical approaches,our study elucidates the complex relationship between strain and moirépotential,thereby opening avenues for generating strain-induced moiréexciton single-photon sources.

关键词： moirésuperlattices strain engineering moiréexcitons moirépotential

Preparation of Fe-As alloys by mechanical alloying and vacuum hot-pressed sintering:microstructure evolution,mechanical properties,and mechanisms

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Rare Metals 2024年第8期43卷 3876-3892页

作者： Fei Chai Fei-Ping Zhao Zhan Hu Shi-Yi Wen Ben-Hammouda Samia Ze-Lin Fu Xin-Ting Lai Yan-Jie Liang Xiao-Bo Min Li-Yuan Chai School of Metallurgy and Environment Central South University Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution Institute of Environmental EngineeringCentral South University State Key laboratory of Powder Metallurgy Central South University Department of Building Civiland Environmental Engineering Concordia University

Arsenic materials have attracted great attention due to their unique ***,research concerning iron-arsenic（Fe-As） alloys is very scarce due to the volatility of As at low temperature and the high melting point of ***,a new Fe-As alloy was obtained by mechanical alloying（MA） followed by vacuum hot-pressed sintering（VHPS）.Moreover,a systematic study was carried out on the microstructural evolution,phase composition,leaching toxicity of As,and physical and mechanical properties of Fe-As alloys with varying weight fractions of As（20%,25%,30%,35%,45%,55%,65%,and 75%）.The results showed that pre-alloyed metallic powders（PAMPs） have a fine grain size and specific supersaturated solid solution after MA,which could effectively improve the mechanical properties of Fe-As alloys by VHPS.A high density(> 7.350 g·cm-3),low toxicity,and excellent mechanical properties could be obtained for FeAs alloys sintered via VHPS by adding an appropriate amount of As,which is more valuable than commercial Fe-As *** Fe-25% As alloy with low toxicity and a relatively high density(7.635 g·cm-3) provides an ultra-high compressive strength（1989.19 MPa）,while the Fe-65% As alloy owns the maximum Vickers hardness（HVo.5 899.41）.After leaching by the toxicity characteristic leaching procedure（TCLP）,these alloys could still maintain good mechanical performance,and the strengthening mechanisms of Fe-As alloys before and after leaching were *** in the grain size,micro structure,and phase distribution induced significant differences in the compressive strength and hardness.

关键词： Mechanical alloying Vacuum hot-pressed sintering High-pressure Arsenic–iron alloys Mechanical properties

Weatherability and heat resistance enhanced by interaction between AG25 and Mg/AI-LDH

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Rare Metals 2024年第6期43卷 2758-2768页

作者： Pei-Yao Yang Xiang-Cui Liu Yu-Chao Wang Huan-Ran Zheng Jin-Xian Wang Jia-Yi Zheng Meng-Jie Liu Dan-Ni Deng Yu Bai Ying-Bi Chen Tong Zhang Zhi-Ming Liu Yong-Peng Lei State Key laboratory of Powder Metallurgy Powder Metallurgy Research InstituteCentral South UniversityChangsha 410083China Research institute of Chemical Defense Beijing 102205China

Although inorganic pigments in common spectral tuning materials show good weatherability and heat resistance,the limited color choices,weak coloring power,poor dispersibility,and a possibility of toxicity limit their *** the basis of organic pigments which possess a wide range of colors,high coloring power,good transparency,and high safety,herein,the modified pigment and biomimetic coating with improved weatherability,especially ultraviolet(UV)resistance(from 2 to 6 days),was achieved by intercalating acid green 25(AG25)pigment into Mg/Al-layered double hydroxides(Mg/Al-LDH).Furthermore,the heat resistance of AG25 was also significantly ***,the spectral stability of pigments after heat treatment is superior with almost unchanged spectral profile and green reflection *** formation of strong N-H bonds and the S-M(Mg,Al)bonds between Mg/Al-LDH laminates and AG25 molecules contributes to the *** work shows potential for biomimetic leaf materials in respect of reflective spectra stability.

关键词： Layered double hydroxide Biomimetic Acid green 25 Interaction Weatherability Heat resistance

Influence of ground effect on flow field structure and aerodynamic noise of high-speed trains

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第2期25卷 147-160页

作者： Xiaoming TAN Linli GONG Xiaohong ZHANG Zhigang YANG Key laboratory of Intelligent Manufacturing and Service Performance Optimization of Laser and Grinding in Mechanical Industry Hunan Institute of Science and TechnologyYueyang414000China Key laboratory of Traffic Safety on Track(central South University) Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha410075China

The simulation of the ground effect has always been a technical difficulty in wind tunnel tests of high-speed *** this paper,large eddy simulation and the curl acoustic integral equation were used to simulate the flow-acoustic field results of high-speed trains under four ground simulation systems(GSSs):“moving ground+rotating wheel”,“stationary ground+rotating wheel”,“moving ground+stationary wheel”,and“stationary ground+stationary wheel”.By comparing the fluid-acoustic field results of the four GSSs,the influence laws of different GSSs on the flow field structure,aero-acoustic source,and far-field radiation noise characteristics were investigated,providing guidance for the acoustic wind tunnel testing of high-speed *** calculation results of the aerodynamic noise of a 350 km/h high-speed train show that the moving ground and rotating wheel affect mainly the aero-acoustic performance under the train *** influence of the rotating wheel on the equivalent sound source power of the whole vehicle was not more than 5%,but that of the moving ground slip was more than 15%.The average influence of the rotating wheel on the sound pressure level radiated by the whole vehicle was 0.3 dBA,while that of the moving ground was 1.8 dBA.

关键词： High-speed train Aero-acoustics Flow field structure Large eddy simulation Moving ground condition Rotating wheel

Crosslinked solubilizer enables nitrate-enriched carbonate polymer electrolytes for stable,high-voltage lithium metal batteries

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Science Bulletin 2024年第2期69卷 209-217页

作者： Chuyang Jing Kuan Dai Dong Liu Wenran Wang Libao Chen Chunxiao Zhang Weifeng Wei State Key laboratory of Powder Metallurgy Central South UniversityChangsha 410083China College of Materials and Chemical Engineering Hunan Institute of EngineeringXiangtan 411104China

High-voltage lithium metal batteries(LMBs)have been considered promising next-generation highenergy-density ***,commercial carbonate electrolytes can scarcely be employed in LMBs owing to their poor compatibility with metallic lithium.N,N-dimethylacrylamide(DMAA)-a crosslinkable solubilizer with a high Gutmann donor number-is employed to facilitate the dissolution of insoluble lithium nitrate(LiNO3)in carbonate-based electrolytes and to form gel polymer electrolytes(GPEs)through in situ *** Lit solvation structure of the GPEs is regulated using LiNO3 and DMAA,which suppresses the decomposition of LiPFe and facilitates the formation of an inorganic-rich solid electrolyte ***,the Coulombic efficiency(CE)of the LillCu cell assembled with a GPE increases to 98.5%at room temperature,and the high-voltage LillNCM622 cell achieves a capacity retention of 80.1%with a high CE of 99.5%after 400 *** bifunctional polymer electrolytes are anticipated to pave the way for next-generation high-voltage LMBs.

关键词： Crosslinked solubilizer Lithium nitrate Carbonate electrolytes Gel polymer electrolytes Lithium metal batteries