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Influence of coiling temperature on microstructure and mechanical properties of a hot-rolled high-strength steel microalloyed with Ti,Mo and V

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Journal of Iron and Steel Research International 2022年第3期29卷 484-493页

作者： Zhi-xiang Fu geng-wei yang Ru-yang Han Yao-wen Xu Xin-ping Mao Si-qian Bao Gang Zhao Hubei Provincial Key Laboratory for New Processes of Iron Making and Steel Making Wuhan University of Science and TechnologyWuhan430081HubeiChina The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China

Influence of coiling temperature(CT)on the microstructure and mechanical properties of a hot-rolled high-strength steel microalloyed with Ti,Mo and V was *** precipitation behavior of nano-sized particles was investigated by theoretical calculation and quantitative *** the results revealed that V-enriched(Ti,Mo,V)C precipitated in the ferrite *** the CT decreased,the site fractions of Ti in(Ti,Mo,V)C changed little,the site fractions of Mo increased,and the site fractions of V decreased ***,the low CT could refine the microstructure and precipitated particles but suppress the precipitation of(Ti,Mo,V)C particles simultaneously,leading to the volume fraction of(Ti,Mo,V)C significantly decreasing,consequently causing an increment of grain refinement strengthening and a reduction in precipitation *** the CT was 600℃,the steel characterized by fine polygonal ferrite,a small amount of bainite and nano-sized(Ti,Mo,V)C precipitates exhibited the optimum mechanical properties with the ultimate tensile strength of 870 MPa,yield strength of 807 MPa and elongation to fracture of 17%.

关键词： Ti-Mo-V complex microalloying Coiling temperature Precipitation Strengthening mechanism Microstructure

Austenite Grain Refinement and Isothermal Growth Behavior in a Low Carbon Vanadium Microalloyed Steel

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Journal of Iron and Steel Research International 2014年第8期21卷 757-764页

作者： geng-wei yang Xin-jun SUN Qi-long YONG Zhao-dong LI Xiao-xian LI Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and Technology Department of Structural Steel Central Iron and Steel Research Institute Department of Materials Science and Engineering Kunming University of Science and Technology

The austenite grain refinement through control of the grain growth during reheating process after thermomechanical controlled process （TMCP） in a vanadium microalloyed steel was achieved. The formation of ultra-fine grained austenite was attributed to the high density of austenite nucleation at the ferrite/martensite structure and to the inhibition of austenite growth by （Ti~ V）C particles at the relatively low reheating temperature. Corresponding with the precipitation behavior of （Ti,V）C with temperature, the growth behavior of austenite in the vanadium mi- croalloyed steel could be divided into two regions. At lower reheating temperature, austenite grains grew slowly, and ultra-fine grained austenite smaller than 5 ~m was successfully obtained. By contrast, the austenite grains grew rap- idly at high temperature due to the dissolution of （Ti, V）C particles. According to the measured and predicted results of austenite growth kinetics, two models were developed to describe the growth behavior of austenite grains in two different temperature regions, and the apparent activation energy Qapp for grain growth was estimated to be about 115 and 195 kJ/mol, respectively.

关键词： grain refinement austenization (Ti, V) C precipitationl grain growth austenite

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钩梢强度对麻竹生物量分配和生理特性的影响

应用生态学报 2016年第10期27卷 3137-3144页

作者：童龙李彬陈丽洁张玮耿养会谢锦忠王玲中国林业科学研究院亚热带林业研究所浙江富阳311400 重庆市林业科学研究院重庆400036 荣昌县林业局重庆荣昌402460

以不钩梢为对照,对笋期内麻竹进行轻度、中度、重度钩梢处理,研究各钩梢处理立竹构件生物量分配、当年生枝条和商品叶生长,以及净光合速率(P_n)、蒸腾速率(T_r)、水分利用效率(WUE)和叶片水势(LWP)等的变化,分析麻竹对营林措施中钩梢强... 详细信息

以不钩梢为对照,对笋期内麻竹进行轻度、中度、重度钩梢处理,研究各钩梢处理立竹构件生物量分配、当年生枝条和商品叶生长,以及净光合速率(P_n)、蒸腾速率(T_r)、水分利用效率(WUE)和叶片水势(LWP)等的变化,分析麻竹对营林措施中钩梢强度的适应机制和生存策略.结果表明:与对照相比,钩梢处理对麻竹生物量及分配影响显著,3个处理麻竹立竹的叶/枝、叶/秆、枝/秆生物量比均显著高于对照.轻度钩梢和中度钩梢处理当年生枝条数量、基径、长度均显著大于对照,其中,中度钩梢处理当年生枝条基径、数量、长度和商品叶数量分别比对照增加43.0%、53.3%、29.8%和39.5%.各钩梢处理麻竹_P_n、T_r、WUE、LWP在笋期内大小为出笋盛期>末期>初期;钩梢后麻竹的P_n、T_r和WUE显著提高,其中,各处理出笋盛期和末期的P_n大小为中度钩梢>轻度钩梢>重度钩梢>对照,且出笋盛期和末期的P_n分别是对照的1.4和1.3倍.各处理出笋初期、盛期和末期的T_r均为重度钩梢>中度钩梢>轻度钩梢>对照.中度钩梢处理对麻竹立竹的生物量分配、商品叶产量和生理特性均有明显优势,并能有效提高麻竹立竹的水分可获得性.

关键词：麻竹钩梢立竹生物量分配

Defect agglomeration in ferroelectric ceramics under cyclic electric field

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Science China(Technological Sciences) 2008年第8期51卷 1296-1305页

作者： geng LiMing yang wei Department of Engineering Mechanics Tsinghua UniversityBeijing 100084China

The agglomeration of point defects in ferroelectric ceramics could be driven by repeated domain switching under cyclic electric field. The evolution equation of pore concentration under cyclic electric field is derived, with the help of a relation between the pore concentration and the extent of pore agglomeration. The results of the simulation agree quantitatively with the experimental data. An integrated framework about the mechanisms of electrically induced fatigue is proposed, which links the mechanisms at different scales.

关键词： point defect domain switch ferroelectric ceramics structural evolution

Intent Pattern Recognition of Lower-limb Motion Based on Mechanical Sensors

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IEEE/CAA Journal of Automatica Sinica 2017年第4期4卷 651-660页

作者： Zuojun Liu wei Lin Yanli geng Peng yang School of Control Science and Engineering Hebei University of Technology Engineering Research Center of Intelligent Rehabilitation Ministry of Education Department of Electrical Engineering and Computer Science Case Western Reserve University Hebei University of Technology

Based on the regularity nature of lower-limb motion,an intent pattern recognition approach for above-knee prosthesis is proposed in this paper. To remedy the defects of recognizer based on electromyogram(EMG), we develop a pure mechanical sensor architecture for intent pattern recognition of lower-limb motion. The sensor system is composed of an accelerometer, a gyroscope mounted on the prosthetic socket, and two pressure sensors mounted under the sole. To compensate the delay in the control of prosthesis, the signals in the stance phase are used to predict the terrain and speed in the swing phase. Specifically, the intent pattern recognizer utilizes intraclass correlation coefficient(ICC) according to the Cartesian product of walking speed and terrain. Moreover, the sensor data are fused via DempsterShafer's theory. And hidden Markov model(HMM) is used to recognize the realtime motion state with the reference of the prior step. The proposed method can infer the prosthesis user's intent of walking on different terrain, which includes level ground,stair ascent, stair descent, up and down ramp. The experiments demonstrate that the intent pattern recognizer is capable of identifying five typical terrain-modes with the rate of 95.8%. The outcome of this investigation is expected to substantially improve the control performance of powered above-knee prosthesis.

关键词： Above-knee prosthesis hidden Markov model(HMM) intra-class correlation coefficient(ICC) intent pattern recognition sensor fusion

Experimental investigation on degradation mechanism of membrane electrode assembly at different humidity under automotive protocol

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Chinese Journal of Chemical Engineering 2023年第4期56卷 70-79页

作者： Jiajun Wang Wenbin yang Jiangtao geng Zhigang Shao wei Song Fuel Cell System and Engineering Laboratory Key Laboratory of Fuel Cells and Hybrid Power SourcesDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100039China

Humidity can affect the attenuation of MEA(membrane electrode assembly), however, the relationship between humidity and MEA decays is complex and ambiguous in realistic application. Herein, we design a simulating automotive protocol, performed on five single fuel cells under RH(relative humidity) 100%,RH 80%, RH 64%, and RH 40%, RH 10%, respectively, to study the relationship of MEA decays and humidity and suggest optimized humidity range to extend the durability. With the electrochemical impedance spectroscopy, cyclic voltammetry, X-ray fluorescence, X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, the four degradation mechanisms about catalyst layer, including Pt dissolution, Pt coarsening, carbon corrosion and ionomer degradation, are observed. Pt coarsening and carbon corrosion are accelerated by higher water content at high humidity. Ionomer degradation and Pt dissolution are enhanced in low humidity. With the linear sweep voltammetry, ion chromatography,nuclear magnetic resonance, tensile test and scan electron microscope, chemical and mechanical degradation in proton exchange membrane are all observed in these five fuels. Chemical degradation, characterized by membrane thinning and more fluoride loss, occurred markedly in RH 10%. Mechanical degradation, characterized by the non-uniformity thickness and bad mechanical properties, is more pronounced in RH 100%, RH 80%, RH 64%. These two degradations are in a moderate level in RH 40%. The research suggests that the RH range from 64% to 40% is conductive to mitigate the degradation of MEAs operated in automotive applications.

关键词： Fuel cell Simulating automotive protocol Relative humidity Degradation Membrane

Design and modification of metal sulfide-based catalysts for lithiumsulfur batteries

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Particuology 2024年第3期86卷 86-100页

作者： Yufei Zhao Chuannan geng Li Wang Haotian yang wei Lv Quan-Hong yang Nanoyang Group State Key Laboratory of Chemical EngineeringSchool of Chemical Engineering and TechnologyNational Industry-Education Integration Platform of Energy Storageand Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin UniversityTianjin300072China Shenzhen Geim Graphene Center Engineering Laboratory for Functionalized Carbon MaterialsTsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen518055China Haihe Laboratory of Sustainable Chemical Transformations Tianjin300192China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou350207China

Metal sulfide(MS)have good conductivity,strong adsorption ability,and excellent catalytic activity for the conversion of sulfur species,and thus,show great promise as the catalysts in LieS ***,the relationship between their properties and electrochemical performance is still ***,further in-depth discussions are required to improve their design in Li-S *** review systematically summarizes the basic structural and electrochemical properties of MSs and highlights the advantages that guarantee them as high-performance catalysts in Li-S ***,various modification strategies for MSs to enhance the catalytic activity,efficiency,and stability are also *** last,future opportunities for MS catalysts in Li-S batteries are proposed.

关键词： Lithium-sulfur battery Metal sulfide Catalysis

Evaluation of Ni-Fe base alloys as inert anode for low-temperature aluminium electrolysis

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Journal of Materials Science & Technology 2022年第12期107卷 216-226页

作者： wei wei Shujiang geng Fuhui Wang Shenyang National Laboratory for Materials Science Northeastern UniversityNo.3-11 Wenhua RoadShenyang 110819China

Isothermal oxidation behaviors of Ni–Fe(wt.%)and of the same alloy with additions of 10 and 15%Cr alloys in the air at 800℃and 900℃and their anodic behaviors in aluminum electrolysis system at 800℃were *** composition morphologies of oxide scales were characterized by XRD,SEM,and *** show that the scales formed on Ni–Fe alloy at both temperatures consisted of an inner(Ni,Fe)Olayer and an outer *** Ni–Fe–10Cr alloy,an external(Ni,Fe)O/FeOlayers and an internal oxidation zone were formed at 800°C,while a continuous CrOlayer forms at the internal oxidation zone/substrate interface at 900°C.A multilayer structure oxide of CrO/(Ni,Fe,Cr)O/(Ni,Fe)O/FeOwas formed on Ni–Fe–15Cr alloy at 800°C,while at 900℃the FeObecomes discontinuous disperses in the(Ni,Fe)Olayer close to the *** in oxidation temperature or Cr content for Ni–Fe–Cr alloys promote the growth of the inner CrOlayer and simultaneously reduce *** 4 h of electrolysis at an anode current density of 0.25 A cm,the oxidation resistance of Ni–Fe–15Cr anode is superior to the Ni–Fe anode.

关键词： Alloy Inert anodes Selective oxidation High temperature corrosion

后路AF系统在胸腰椎骨折的应用及并发症分析

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实用骨科杂志 2003年第6期9卷 498-499页

作者：王德利阮狄克魏更生杨敏杰马巍海军总医院北京100037 西安交通大学第一医院陕西西安710061

目的 :了解后路椎弓根内固定AF系统在胸腰椎骨折中的应用及常见并发症 ,分析手术失误原因及并发症发生机制。方法 :通过应用AF系统对我院 4 0例胸腰段骨折患者进行治疗 ,总结随访结果并分析手术疗效和并发症的原因。结果 :术后随访 ,Fra... 详细信息

目的 :了解后路椎弓根内固定AF系统在胸腰椎骨折中的应用及常见并发症 ,分析手术失误原因及并发症发生机制。方法 :通过应用AF系统对我院 4 0例胸腰段骨折患者进行治疗 ,总结随访结果并分析手术疗效和并发症的原因。结果 :术后随访 ,FrankelA级的 3例 ,术后感觉平面下降或下肢感觉部分恢复 ,运动功能无改善 ;2 7例随访时无明显疼痛 ,4例中度疼痛 ,9例轻度疼痛。随访X线摄片复查 ,38例椎体序列正常 ,腰椎生理前凸存在。无神经根损伤体征 ,无断钉现象。结论 :后路手术不能减压、去除病灶、复位、植骨重建前中柱结构及内固定一次完成。

关键词： AF系统胸腰椎骨折并发症手术治疗