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Tungsten 2024年第3期6卷 610-620页

作者： Jia-Hao Ye liu-jie xu Ji-Kang Hu School of Materials Science and Engineering Henan University of Science and Technology National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials Henan University of Science and Technology

In this work,isothermal compression experiments of macroporous W-4.8 vol.%ZrO2（W-4.8ZrO2） at 1300-1600℃ and strain rate of 0.005-1 s-1were carried out on a Gleeble-1500D thermo-mechanical *** dynamic recovery of W-4.8ZrO2is the main "softening" *** the basis of Arrhenius model,the initial constitutive equation is established by exploring the influence of temperature,strain rate and rheological *** on Arrhenius model,the relationship between flow stress,strain rate and deformation temperature is *** the influence of strain,the improved constitutive equation and the law of material constant changing with the strain are *** that,the hot processing maps were drawn on the basis of the dynamic material model,which is used to analyze the instability mechanism of the W-4.8ZrO2,and determine the appropriate hot working process parameters(temperature:1350-1450℃,strain rate:0.1-1 s-1).

关键词： Tungsten alloy Flow characteristics Constitutive equation Hot processing maps

Real-time Operation Optimization in Active Distribution Networks Based on Multi-agent Deep Reinforcement Learning

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 886-899页

作者： jie xu Hongjun Gao Renjun Wang Junyong liu the College of Electrical Engineering Sichuan UniversityChengduChina

The increasing integration of intermittent renewable energy sources(RESs)poses great challenges to active distribution networks(ADNs),such as frequent voltage *** paper proposes a novel ADN strategy based on multiagent deep reinforcement learning(MADRL),which harnesses the regulating function of switch state transitions for the realtime voltage regulation and loss *** deploying the calculated optimal switch topologies,the distribution network operator will dynamically adjust the distributed energy resources(DERs)to enhance the operation performance of ADNs based on the policies trained by the MADRL *** to the model-free characteristics and the generalization of deep reinforcement learning,the proposed strategy can still achieve optimization objectives even when applied to similar but unseen ***,integrating parameter sharing(PS)and prioritized experience replay(PER)mechanisms substantially improves the strategic performance and *** framework has been tested on modified IEEE 33-bus,IEEE 118-bus,and three-phase unbalanced 123-bus *** results demonstrate the significant real-time regulation capabilities of the proposed strategy.

关键词： Reconfiguration active distribution network distributed energy resource real-time control deep reinforcement learning parameter sharing scalability

A Hierarchical Modeling Framework for Electrochemical Behaviors in Lithium-Ion Batteries with Detailed Structures

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Energy & Environmental Materials 2024年第5期7卷 81-89页

作者： Binghe liu Xin liu Huacui Wang jie Li Jun xu College of Mechanical and Vehicle Engineering Chongqing University State Key Laboratory of Intelligent Vehicle Safety Technology Department of Mechanical Engineering University of Delaware Energy Mechanics and Sustainability Laboratory (EMSLab) University of Delaware

The accurate representation of lithium plating and aging phenomena has posed a persistent challenge within the battery research community. Empirical evidence underscores the pivotal role of cell structure in influencing aging behaviors and lithium plating within lithium-ion batteries (LIBs). Available lithium-ion plating models often falter in detailed description when integrating the structural intricacies. To address this challenge, this study proposes an innovative hierarchical model that intricately incorporates the layered rolling structure in cells. Notably, our model demonstrates a remarkable capacity to predict the non-uniform distribution of current density and overpotential along the rolling direction of LIBs. Subsequently, we delve into an insightful exploration of the structural factors that influence lithium plating behavior,leveraging the foundation laid by our established model. Furthermore, we easily update the hierarchical model by considering aging factors. This aging model effectively anticipates capacity fatigue and lithium plating tendencies across individual layers of LIBs, all while maintaining computational efficiency.

关键词： aging model battery design hierarchical modeling lithium plating lithium-ion battery

Single-atom catalysis for advanced oxidation and reduction systems in water decontamination

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Rare Metals 2024年第8期43卷 3576-3606页

作者： jie Teng Jin-Hui xu Wen-Xin Sun xue-Feng liu Xia xu Guo-Shuai liu School of Urban Construction Changzhou UniversityChangzhou 213164China School of Environmental and Civil Engineering Jiangnan UniversityWuxi 214122China

Water scarcity is an escalating global crisis,posing a severe threat to populations ***,exploring various materials to remove emerging contaminants from freshwater sources has garnered significant *** this regard,single-atom catalysis(SACs) has emerged as a catalyst of scientific progress in water purification and treatment methodologies during recent *** exhibit exceptional catalytic activity,selectivity and stability,due to their near-perfect atom utilization,highly unsaturated coordination environment and uniform reaction ***,a comprehensive and critical review encompassing the successful integration of SACs into water purification processes needs to be *** review aims to accentuate recent trends by presenting the synthesis,structure,and environment and energy application-relevant properties of *** results show that a comprehensive and multi-perspective summary of the advantages of SACs in environmental remediation can have significant benefits,such as fast kinetics,costeffectiveness,*** oxidation and reduction processes of SACs and functional SACs materials in water purification were ***,the last section is devoted to the current research gaps and further perspectives on the application of SACs in water treatment,which are summarized and analyzed.

关键词： Single-atom catalysis Water treatment Oxidation Reduction

The influence of stress-dependent overpotential on dendrite growth in all-solid-state battery with cracks

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Science China(Technological Sciences) 2024年第8期67卷 2493-2504页

作者： ZHANG ZhenHua ZHANG Yong liu Chang HOU xu WANG jie Department of Engineering Mechanics School of Aeronautics and AstronauticsZhejiang UniversityHangzhou 310027China Zhejiang Laboratory Hangzhou 311100China Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Zhejiang UniversityHangzhou 310027China School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and Aerospace EngineeringSouthwest Jiaotong UniversityChengdu 610031China Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China

Dendrite growth is one of the main challenges in maintaining the service life of all-solid-state lithium-ion *** stress has been reported to significantly affect dendrite *** this study,to explain the effect of mechanical stress on electrochemical reactions in all-solid-state batteries,a modified phase-field model for dendrite growth is proposed by considering the stress-dependent *** growth under different mechanical loadings in an all-solid-state battery is investigated using the proposed *** with previous experimental results,the current result shows that compressive stress inhibits dendrite *** the stress concentration at the tips of processing-induced microcracks,the effects of the number and distribution of microcracks on dendrite growth are *** results show that the stress-concentration field induced at the tips of cracks or voids can change the morphology of dendrites and decrease their growth *** study provides a new perspective for explaining Li dendrite growth under mechanical stress and offers inspiration for prolonging the service life of all-solid-state batteries based on defect and stress regulation,which may be further realized in experiments by filling solid electrolytes with different types of nanofillers.

关键词： Butler–Volmer equation stress-dependent overpotential microcracks all-solid-state battery phase-field simulation

Unsaturated bi-heterometal clusters in metal-vacancy sites of 2D MoS2 for efficient hydrogen evolution

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Carbon Energy 2024年第3期6卷 264-275页

作者： Gonglei Shao jie xu Shasha Gao Zhang Zhang Song liu xu Zhang Zhen Zhou Interdisciplinary Research Center for Sustainable Energy Science and Engineering(IRC4SE2) School of Chemical EngineeringZhengzhou UniversityZhengzhouHenanChina College of Chemistry and Materials Engineering Wenzhou UniversityWenzhouZhejiangChina Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjinChina State Key Laboratory of Chemo/Biosensing and Chemometrics Institute of Chemical Biology and Nanomedicine(ICBN)College of Chemistry and Chemical EngineeringHunan UniversityChangshaHunanChina Institute of New Energy Material Chemistry School of Materials Science and EngineeringNankai UniversityTianjinChina

The valence states and coordination structures of doped heterometal atoms in two-dimensional(2D)nanomaterials lack predictable regulation ***,a robust method is proposed to form unsaturated heteroatom clusters via the metal-vacancy restraint mechanism,which can precisely regulate the bonding and valence state of heterometal atoms doped in 2D molybdenum *** unsaturated valence state of heterometal Pt and Ru cluster atoms form a spatial coordination structure with Pt–S and Ru–O–S as catalytically active *** them,the strong binding energy of negatively charged suspended S and O sites for H+,as well as the weak adsorption of positively charged unsaturated heterometal atoms for H*,reduces the energy barrier of the hydrogen evolution reaction proved by theoretical ***,the electrocatalytic hydrogen evolution performance is markedly improved by the ensemble effect of unsaturated heterometal atoms and highlighted with an overpotential of 84 mV and Tafel slope of 68.5 mV dec^(−1).In brief,this metal vacancy-induced valence state regulation of heterometal can manipulate the coordination structure and catalytic activity of heterometal atoms doped in the 2D atomic lattice but not limited to 2D nanomaterials.

关键词： clusters hydrogen evolution reaction metal vacancy MoS2 unsaturated heterometal

Properties and microstructure of oxide dispersion strengthened tungsten alloy prepared by liquid-phase method:a review

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钨科技(英文) 2023年第4期5卷 481-502页

作者： liu-jie xu Zhou Li Fang-Nao Xiao Yun-Chao Zhao Yu-Cheng Zhou Shi-Zhong Wei National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials Henan University of Science and TechnologyLuoyang471003China Henan Key Laboratory of High-temperature Structural and Functional Materials Henan University of Science and TechnologyLuoyang471003China College of Material Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing201116China

The addition of the second phase into tungsten can significantly refine the grain size of tungsten alloys,and also play a role in dispersion strengthening,thus improving the properties of tungsten *** a preparation method of tungsten alloy powder,liquid-phase method avoids the disadvantage of mechanical alloying,and the obtained powder composition is accurate and controllable,with high purity and excellent *** present,the second phase particles used for dispersion strengthening tungsten alloys are mainly composed of *** particles can be synthesized and precipitated in nitrate solution through in situ chemical reaction,and are uniformly distributed in composite powder by mixing and ***,the oxide dispersion strengthened tungsten alloy(ODS-W)was obtained by reduction and ***-phase methods for preparing ODS-W alloys include azeotropic distillation,sol-gel methods,freeze-drying,hydrothermal synthesis,spray-drying,*** this paper,several liquid-phase methods for preparing tungsten alloy composite powder precursors are reviewed,and their latest research progresses are *** addition,the morphologies and properties of tungsten alloys prepared by different methods are compared,which provides guidance for preparing high-performance tungsten alloys.

关键词： Tungsten alloy ODS-W Liquid-phase method Microstructure Property

Effect of surface modification on thermal expansion of Zr_(2)WP_(2)O_(12)/aromatic polyimides based composites

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Tungsten 2023年第1期5卷 179-188页

作者： Xin-Wei Shi Sen Zhang Qiang Zhou Jing Li Bai-Lin Zhu liu-jie xu Qi-Long Gao School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Henan Key Laboratory of High-Temperature Structural and Functional Materials Henan University of Science and TechnologyLuoyang 471003China

Surface modification is a fascinating way to improve the compounding effect between inorganic fillers and *** this study,zirconium tungsten phosphate(ZWP) with negative thermal expansion was surface modified by silane coupling agent 3-(Trimethoxysilyl)propyl *** effects of surface modification and the modification mechanism were analyzed in detail by X-ray diffractometer,scanning electron microscopy,Fourier transform infrared spectroscopy and thermal mechanical *** surface modification could effectively reduce the thermal expansion properties of the *** the added amount of 3-methacryloxypropyl trimethoxysilaneSilane(trade name:KH570) is 0.50 wt%,the thermal expansion coefficient of ZWP/Aromatic polyimide composite decreased by 9.76%.The surface modification also can effectively improve the dielectric performance of aromatic *** present work provides one new way to improve the thermal expansion behavior of composites.

关键词： Negative thermal expansion Tungsten Surface modification Polyimide composite Silane coupling agent

Span-based joint entity and relation extraction augmented with sequence tagging mechanism

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Science China(Information Sciences) 2024年第5期67卷 84-98页

作者： Bin JI Shasha LI Hao xu jie YU Jun MA Huijun liu Jing YANG College of Computer National University of Defense Technology

Span-based joint extraction simultaneously conducts named entity recognition(NER) and relation extraction(RE) in a text span form. However, since previous span-based models rely on span-level classifications, they cannot benefit from token-level label information, which has been proven advantageous for the task. In this paper, we propose a sequence tagging augmented span-based network(STSN), a spanbased joint model that can make use of token-level label information. In STSN, we construct a core neural architecture by deep stacking multiple attention layers, each of which consists of three basic attention *** the one hand, the core architecture enables our model to learn token-level label information via the sequence tagging mechanism and then uses the information in the span-based joint extraction; on the other hand, it establishes a bi-directional information interaction between NER and RE. Experimental results on three benchmark datasets show that STSN consistently outperforms the strongest baselines in terms of F1,creating new state-of-the-art results.

关键词： joint extraction named entity recognition relation extraction span sequence tagging mechanism

Metal–organic framework wafer enabled fast response radiation detection with ultra-low dark current

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Nano Research 2024年第4期17卷 2988-2993页

作者： Meng xu Jianxi liu Wei Wu Yang Chen Donghao Ma Sixin Chen Wanqi jie Menghua Zhu Yadong xu State Key Laboratory of Solidification Processing MIIT Key Laboratory of Radiation Detection Materials and Devices&School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China

Semiconductive metal–organic frameworks(MOFs)have attracted great interest for the electronic ***,dark currents of present hybrid organic–inorganic materials are 1000–10,000 times higher than those of commercial inorganic detectors,leading to poor charge ***,we demonstrate a ZIF-8(Zn(mim)_(2),mim=2-methylimidazolate)wafer with ultra-low dark current of 1.27 pA·mm^(-2) under high electric fields of 322 V·mm^(-1).The isostatic pressing preparation process provides ZIF-8 wafers with good ***,the presence of redox-active metals and small spatial separation between components promotes the charge *** ZIF-8-based semiconductor detector shows promising X-ray detection sensitivity of 70.82μC·Gy^(-1)·cm^(-2) with low doses exposures,contributing to superior X-ray imaging capability with a relatively high spatial resolution of 1.2 lp·mm^(-1).Simultaneously,good peak discrimination with the energy resolution of~43.78%is disclosed when the detector is illuminated by uncollimated 241Am@5.48 MeVα-*** results provide a broad prospect of MOFs for future radiation detection applications.

关键词： MOFs lead-free α-particles X-ray detection and imaging dark current fast response