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Simulation of macrosegregation in a 36-t steel ingot using a multiphase model

International Journal of Minerals,Metallurgy and materials 2020年第2期27卷 200-209页

作者： Zhuo Chen Hou-fa Shen Key Laboratory for Advanced Material Processing Technology Ministry of Education School of Material Science and Engineering Tsinghua University

Macrosegregation is the major defect in large steel ingots caused by solute partitioning and melt convection during *** this study,a three-phase(liquid,columnar dendrites,and equiaxed grains)model is proposed to simulate macrosegregation in a 36-t steel ingot.A supplementary set of conservation equations are employed in the model such that two types of equiaxed grains,either settling or adhering to the solid shell,are well *** predicted concentration agrees quantitatively with the experimental value.A negative segregation cone was located at the bottom owing to the grain settlement and solute-enriched melt leaving from the mushy *** interdendritic liquid flow was carefully analyzed,and the formation of A-type segregations in the mid-height of the ingot is *** segregation was observed near the riser neck due to the specific relationship between flow direction and temperature ***,the as-cast macrostructure of the ingot is presented,including the grain size distribution and columnar–equiaxed transition.

关键词： macrosegregation multiphase model transportation solidification steel ingot

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Poly(dopamine)-assisted Bioactive Coating on the Surface of Porous Poly (Ether Ether Ketone) to Promote Osteogenic Differentiation of rBMSC

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Journal of Wuhan University of Technology(materials Science) 2021年第5期36卷 766-776页

作者： WANG Jin WANG Youfa WU Qingzhi State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Biomedical Material and Engineering Center of Hubei ProvinceWuhan University of TechnologyWuhan 430070China

A facile modification strategy is developed to promote the proliferation and osteogenic differentiation of rat bone marrow stromal cells(rBMSCs)through deposition of a bioactive calcium silicate(CS)coating on the porous surface of poly(ether-ether-ketone)(PEEK)with the assistance of poly(dopamine)(PDA).The porous structures are etched on the surface of PEEK after sulfonation treatment.A poly(dopamine)layer is coated on the porous surface of the sulfonated PEEK(SPEEK),which provides anchoring groups for the subsequent deposition of the CS *** show that the CS coating on the porous surface of SPEEK significantly improve the hydrophilicity and biomineralization formation of *** with PEEK,SPEEK-PDA-CS displays higher bioactivity to promote the proliferation and osteogenic differentiation of rBMSCs,including the increase of ALP activity and formation of calcium nodules,the expression of osteogenic differentiation-related *** results are beneficial to extending clinical applications of PEEK-based implants for bone tissue repair and orthopedic surgery.

关键词： poly(ether-ether-ketone) calcium silicate poly(dopamine) bioactivity osteogenic differentiation

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Mixed 2D-Dion–Jacobson/3D Sn-Pb alloyed perovskites for efficient photovoltaic solar devices

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Nano Research 2023年第2期16卷 3142-3148页

作者： Zhili Lu Chaohui Li Hongwei Lai Xinming Zhou Chunfeng Wang Xianhu Liu Fei Guo Caofeng Pan National Engineering Research Center for Advanced Polymer Processing Technology Key Laboratory of Advanced Material Processing&Mold(Ministry of Education)Zhengzhou UniversityZhengzhou 450002China Institute of New Energy Technology College of Information Science and TechnologyJinan UniversityGuangzhou 510632China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesNational Center for Nanoscience and Technology(NCNST)Beijing 100083China Institute of Materials for Electronics and Energy Technology(i-MEET) Friedrich-Alexander University Erlangen-NürnbergMartensstrasse 7Erlangen 91058Germany

Tin-lead(Sn-Pb)alloyed perovskites with tunable bandgaps hold great potential for constructing highly efficient single-junction and tandem photovoltaic ***,the efficiency and stability of Sn-Pb perovskite solar cells(PSCs)are greatly hampered by severe nonradiative recombination due to the easy oxidation of Sn(II).In this work,we report the construction of mixed dimensional two-dimensional(2D)Dion–Jacobson(DJ)and three-dimensional(3D)perovskites to improve the efficiency and stability of Sn-Pb alloyed *** a small amount of 1,4-butanediammonium diiodide as spacer cations of DJ perovskites into precursor,the prepared mixed dimensional Sn-Pb alloyed perovskites exhibit reduced trap-state density due to the passivation of 2D DJ *** a result,nonradiative charge recombination is greatly *** prepared Sn-Pb alloyed PSCs based on 2D-DJ/3D heterojunction deliver a power conversion efficiency of 19.02%with an impressive fill factor of 80%.As well,improved device stability is realized due to the presence of DJ perovskites which serves as a protection barrier against oxidation and water invasion.

关键词： Sn-Pb perovskite narrow bandgap Dion–Jacobson perovskite solar cells two-dimensional(2D)/three-dimensional(3D)

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Growth of magnetic metals on carbon microspheres with synergetic dissipation abilities to broaden microwave absorption

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Journal of materials Science & Technology 2022年第12期107卷 100-110页

作者： Biao Zhao Yang Li Qingwen Zeng Bingbing Fan Lei Wang Rui Zhang Renchao Che Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative MaterialsFudan UniversityShanghai 200438China Department of Materials Science Fudan UniversityShanghai 200438China Henan Key Laboratory of Aeronautical Materials and Application Technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhouHenan 450046China School of Material Science and Engineering Zhengzhou UniversityZhengzhouHenan 450001China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

Microwave absorption(MA) materials have been captured extensive attentions due to the serious electromagnetic(EM) pollution. Numerous interests focus on the MA performances of core-shell structural composites with magnetic constituents as cores and dielectric constituents as shells, which inevitably suppressed the magnetic coupling causing the decrease of magnetic loss to some extent. Herein, the coreshell structural carbon(C) microsphere/magnetic metal composites were fabricated through the combination of an electrostatic assembly approach and subsequent in-situ reduction reaction. The complex permittivity and permeability of core-shell C@magnetic metal composite system can be effective adjusted by the constituent and microstructure of shells. Thanks to the distinct magnetic coupling from the subtle designed structures and the promotion of the magnetic-dielectric synergy, the C@magnetic metal composite exhibited enhanced MA properties. The optimal reflection loss(RL) of C@Ni composite was-54.1 dB with a thickness of 3.4 mm, meanwhile the effective absorbing band could reach over 5.5 GHz at only a1.8 mm thickness. Broad absorption bandwidth with RL below-10 d B could achieve 6.0 GHz and 6.7 GHz for C@Co and C@Ni Co composites with a thin 2.1 mm thickness, respectively. Our exciting findings might lead a guide on the novel structure design for the functional core-shell structural composites used for microwave absorption.

关键词： Microwave absorption Core-shell structure C@magnetic metal composite Interfacial polarization Magnetic coupling

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Internal magnetic-field-enhanced photogenerated charge separation in ferromagnetic TiO_(2)surface heterojunctions

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Journal of materials Science & Technology 2023年第29期160卷 240-247页

作者： Guojing Wang Shirong Xiong Yonghui Chen Chunchang Wang Shasha Lv Ke Jia Yunjie Xiang Jianbo Liu Chong Liu Zhengcao Li School of Materials and Energy Lanzhou UniversityLanzhou 730000China State Key Laboratory of New Ceramics and Fine Processing Key Laboratory of Advanced Materials(MOE)School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Laboratory of Dielectric Functional Materials School of Physics and Material ScienceAnhui UniversityHefei 230601China Key Laboratory of Beam Technology Ministry of EducationCollege of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China School of Materials and Energy Southwest UniversityChongqing 404100China

The use of the internal magnetic field of ferromagnets can effectively promote charge separation and transfer(CST)in photoelectrochemical energy ***,photoelectrochemical materials with a ferromagnetic field are scarce,and the internal magnetic field is negligible in nonferromagnetic *** address this issue,we propose a rational method for preparing ferromagnetic TiO_(2)powder using controllable oxygen vacancies in anatase TiO_(2)with co-exposed{001}and{101}***,an ex-cellent saturation magnetisation of 0.0014 emu/g in TiO_(2)is achieved owing to an asymmetric and uneven charge *** with that of nonferromagnetic TiO_(2),the efficiency of photocatalytic hydro-gen generation of ferromagnetic TiO_(2)is improved by 0.64 *** enhancement of photocatalytic hy-drogen generation is due to the different forces exerted on the electrons and holes in the magnetic field,which significantly improve the photogenerated CST efficiency of ferromagnetic TiO_(2).This result high-lights the significant role of the synergistic regulation of the crystal structure and defects in regulating the ferromagnetic characteristics of *** findings of this study provide guidance for leveraging point defects to promote CST for high-efficiency solar-energy conversion systems.

关键词： Photocatalysis TiO_(2){001}-{101}surface heterojunctions Oxygen vacancies Ferromagnetic

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调节铜催化剂表面分子亲电性以调控电催化二氧化碳还原选择性

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Science China materials 2024年第6期67卷 1858-1865页

作者：周贤龙单洁琼郑敏李欢夏宝玉郑尧 School of Chemical Engineering and Advanced Materials The University of AdelaideAdelaideSA 5005Australia Key Laboratory of Material Chemistry for Energy Conversion and Storage(Ministry of Education) Hubei Key Laboratory of Material Chemistry and Service FailureNational Laboratory for OptoelectronicsSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074China Jiangsu Co-Innovation Centre of Efficient Processing and Utilization of Forest Resources College of Chemical EngineeringNanjing Forestry UniversityNanjing 210037China

Cu是唯一能选择性将二氧化碳电还原(CRR)为多碳产物的过渡金属.然而,调控Cu的CRR选择性获得多种产物仍非常具有挑战性.本文选择了一系列具有不同亲电性的分子来修饰Cu催化剂以调控其CRR选择性,从而产生CH_(4)或C_(2)H_(4).理论计算表明... 详细信息

Cu是唯一能选择性将二氧化碳电还原(CRR)为多碳产物的过渡金属.然而,调控Cu的CRR选择性获得多种产物仍非常具有挑战性.本文选择了一系列具有不同亲电性的分子来修饰Cu催化剂以调控其CRR选择性,从而产生CH_(4)或C_(2)H_(4).理论计算表明,分子的亲电性决定催化反应中的质子活度,进而能促进或抑制CRR中的质子耦合电子转移(PCET)过程.实验发现,低亲电性分子(如1,2-双(4-吡啶基)乙烷)可以促进质子转移,加快^(*)CO中间体氢化过程而生成CH_(4),实现58.2%的法拉第效率;而高亲电性分子(如顺-1,2-双(4-吡啶基)乙烯)能构建强的氢键以稳定^(*)CO中间体,促进其偶联生成C_(2)H_(4),实现65.9%的法拉第效率.理论计算结合原位光谱表征揭示,分子亲电性可调节催化剂质子活度,影响CRR反应中^(*)CO氢化或偶联,进而调控CRR选择性.不同于常规的催化剂结构工程,本策略通过调节CRR中的PCET过程来调控选择性,为CRR的发展提供了新的认识.

关键词： molecular electrophilicity Cu catalysts proton transfer CO_(2)electroreduction C1/C2 selectivity

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Cobalt doping boosted electrocatalytic activity of CaMn3O6 for hydrogen evolution reaction

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Nano Research 2022年第4期15卷 2870-2876页

作者： Qun Li Kaisi Liu Siwei Gui Jiabin Wu Xiaogang Li Zaifang Li Hongrun Jin Hui Yang Zhimi Hu Wenxi Liang Liang Huang Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China China-Australia Institute for Advanced Materials and Manufacturing Jiaxing UniversityJiaxing 314001China State Key Laboratory of Material Processing and Die&Mold Technology Department of MechanicsSchool of Aerospace EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The development of earth-abundant-metal-based electrocatalysts with high efficiency and long-term stability for hydrogen evolution reaction(HER)is crucial for the clean and renewable energy ***,we report a molten-salt method to synthesize Co-doped CaMn_(3)O_(6)(CMO)nanowires(NWs)as effective electrocatalyst for *** as-obtained CaMn_(3-x)Co_(x)O_(6)(CMCO)exhibits a small onset overpotential of 70 mV,a required overpotential of 140 mV at a current density of 10 mA·cm^(-2),a Tafel slope of 39 mV·dec^(-1)in 0.1 M HClO_(4),and a satisfying long-term *** characterizations combined with density functional theory(DFT)calculations demonstrate that the obtained HER performance can be attributed to the Co-doping which altered CMO’s surface electronic structures and *** the simplicity of synthesis route and the abundance of the pertinent elements,the synthesized CMCO shows a promising prospect as a candidate for the development of earth-abundant,metal-based,and cost-effective electrocatalyst with superior HER *** results also establish a strategy of rational design and construction of novel electrocatalyst toward HER by tailoring band structures of transition metal oxides(TMOs).

关键词： CMCO nanowires hydrogen evolution reaction electronic structure dopant

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Promising commercial fabrics with radiative cooling for personal thermal management

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Science Bulletin 2022年第3期67卷 229-231页

作者： Xin Zhang Chuntai Liu Changyu Shen Xianhu Liu National Engineering Research Center for Advanced Polymer Processing Technology Key Laboratory of Advanced Material Processing&Mold(Ministry of Education)Zhengzhou UniversityZhengzhou 450002China

With global warming,the need for cooling is *** 15%of the world’s electricity consumption and 10%of greenhouse gas emissions are due to cooling systems[1],mainly because a large amount of cooling load is used to reduce the temperature of the environment or objects and cannot be efficiently applied to the human ***,personal thermal management(PTM)as an efficient cooling method has gained widespread attention in recent years[2,3].Researchers from Stanford University have successfully produced nano-polyethylene that can effectively reduce the temperature of the human body fabric[4].However,to ensure a high transmittance of the fabric through the atmospheric window(wavelength:8<λ<13μm),its thickness is *** effect of solar heat transfer increases as the thickness of the fabric decreases,so fabrics that can effectively manage human heat remain a challenge.

关键词：辐射制冷 gained fabric

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引用

Chinese Chemical Letters 2024年第8期35卷 25-35页

作者： Yatian Deng Dao Wang Jinglan Cheng Yunkun Zhao Zongbao Li Chunyan Zang Jian Li Lichao Jia School of Materials Science and Engineering State Key Lab of Material Processing and Die&Mould TechnologyHuazhong University of Science and TechnologyWuhan 430074China College of Science Qiongtai Normal UniversityHaikou 571127China Kunming Sino-Platinum Metals Catalyst Co. Ltd.Kunming 650106China State Key Laboratory of Advanced Electromagnetic Technology Huazhong University of Science and TechnologyWuhan 430074China

Catalyst with high performance has drawn increasing attention recently due to its significant advantages in chemical reactions such as speeding up the reaction,lowering the reaction temperature or pressure,and proceeding without itself being *** the superior catalytic performance of precious metal catalysts,transition metal oxides offer a promising route for substitution of precious metals in catalysis arising from their low cost,intrinsic activity and sufficient ***-type oxide SmMn_(2)O_(5) exhibits a unique crystal structure containing double crystalline fields,and nowadays is used widely as the catalyst in different chemical reactions,including the reactions of vehicle emissions reduction and oxygen evolution reaction,gas sensors,and metal-air batteries,promoting attention in catalytic perfor-mance *** our knowledge,there is no review article covering the comprehensive informa-tion of SmMn2 O 5 and its *** we review the recent progress in understanding of the crys-tal structure of SmMn_(2)O_(5) and its basic physical *** then summarize the catalytic sources of SmMn_(2)O_(5) and reaction mechanisms,while the strategies to improve catalytic performance of SmMn_(2)O_(5) are further ***,we provide a perspective on how to make further progress in catalytic applications.

关键词： Catalyst SmMn_(2)O_(5) Mullite-type oxide Catalytic oxidation Oxygen reduction reaction Oxygen evolution reaction Reaction mechanisms

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engineering single atomic ruthenium on defective nickel vanadium layered double hydroxide for highly efficient hydrogen evolution

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Nano Research 2023年第4期16卷 4612-4619页

作者： Xiaoyu Chen Jiawei Wan Meng Zheng Jin Wang Qinghua Zhang Lin Gu Lirong Zheng Xianzhu Fu Ranbo Yu College of Materials Science and Engineering Shenzhen UniversityShenzhen 518071China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China Department of Physical Chemistry School of Metallurgical and Ecological EngineeringUniversity of Science and Technology Beijing InstitutionBeijing 100083China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials Department of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Key Laboratory of Advanced Material Processing&Mold Ministry of EducationZhengzhou UniversityZhengzhou 450002China

Fabricating single-atom catalysts(SACs)with high catalytic activity as well as great stability is a big ***,we propose a precise synthesis strategy to stabilize single atomic ruthenium through regulating vanadium defects of nickel vanadium layered double hydroxides(NiV-LDH)ultrathin nanoribbons ***,the isolated atomically Ru doped NiV-LDH ultrathin nanoribbons(NiVRu-R)were successfully fabricated with a super-high Ru load of 12.8 wt.%.X-ray absorption spectrum(XAS)characterization further confirmed atomic dispersion of *** catalysts for electrocatalytic hydrogen evolution reaction(HER)in alkaline media,the NiVRu-R demonstrated superior catalytic properties to the commercial Pt/***,it maintained exceptional stability even after 5,000 cyclic voltammetry ***-situ XAS and density functional theory(DFT)calculations prove that the Ru atomic sites are stabilized on supports through forming the Ru-O-V structure,which also help promote the catalytic properties through reducing the energy barrier on atomic Ru catalytic sites.

关键词： hydrogen evolution reaction layered double hydroxide ruthenium atomic site ultrathin nanoribbons

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