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hardness-thermal stability synergy in nanograined Ni and Ni alloys:Superposition of nanotwin and low-energy columnar boundary

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Journal of Materials Science & Technology 2023年第6期137卷 123-131页

作者： f.h.duan Y.Lin Q.Li J.h.Luan J.Lu J.Pan Y.Li Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Laboratory of Nanomaterials&Nanomechanics Department of Mechanical EngineeringCity University of Hong KongHong KongChina State Key Laboratory of Material Processing and Die&Mould Technology and School of Materials Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China Department of Materials Science and Engineering City University of Hong KongHong KongChina Centre for Advanced Structural Materials Greater Bay Joint DivisionShenyang National Laboratory for Materials ScienceCity University of Hong Kong Shenzhen Research InstituteShenzhen 518057China City U-Shenzhen futian Research Institute Shenzhen 518045China

Refining grains into nanoscale can significantly strengthen and harden metallic materials;however,nanograined metals generally exhibit low thermal stability,hindering their practical applications.In this work,we exploit the superposition of the contribution of nanotwins,low-angle grain boundaries,and microalloying to tailor superior combinations of high hardness and good thermal stability in Ni and Ni alloys.for the nanotwinned Ni having a twin thickness of∼2.9 nm and grain size of 28 nm,it exhibits a hardness over 8.0 GPa and an onset coarsening temperature of 623 K,both of which are well above those of nanograined Ni.Re/Mo microalloying can further improve the onset coarsening temperature to 773 K without comprising hardness.Our analyses reveal that high hardness is achieved via strengthen-ing offered by extremely fine nanotwins.Meanwhile,the superior thermal stability is mainly ascribed to the low driving force for grain growth induced by the low-angle columnar boundary architecture and to the additional pinning effect on the migration of twin/columnar boundaries provided by minor Re/Mo solutes.The present work not only reveals a family of nanotwinned metals possessing the combination of ultra-high hardness and high thermal stability but also provides a strategy for tailoring properties of metallic materials by pairing low-angle grain boundaries and twin boundaries.

关键词： Nanotwin Thermal stability hardness Low-angle grain boundary Microalloying

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Unexpected creep behavior in a rejuvenated metallic glass

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Journal of Materials Science & Technology 2023年第32期163卷 140-149页

作者： J.P.Wu Y.Lin f.h.duan Q.Chen h.T.Wang N.Li J.L.Wen J.Pan L.Liu Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Material Processing and Die&Mould Technology and School of Materials Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China Laboratory of Nanomaterials&Nanomechanics Department of Mechanical EngineeringCity University of Hong KongHong KongChina Wuhan National high Magnetic field Center Huazhong University of Science and TechnologyWuhan 430074China Shenzhen Polytechnic Shenzhen 518055China

Rejuvenation,bringing metallic glasses(MGs)to the younger and higher energy states,provides an alternative avenue to explore the interplay between the property and microstructures of MGs.In this study,the creep behavior of the Zr_(69.5)Cu_(12)Ni_(11)Al_(7.5)MGs was experimentally examined by controlling the energy state in terms of structural rejuvenation and thermal annealing.It is found that compared to the as-cast counterpart,the annealed MG at a lower energy state exhibits a higher hardness,a smaller displacement,and a lower creep rate due to the decreased free volume and the inhibited activation of the shear transformation zone.Conversely,the rejuvenated MG at a high energy state displays lower hardness and increased free volume content,yet it demonstrates superior creep resistance compared to its as-cast counterpart,which deviates from conventional understanding.This unexpected phenomenon occurs as the initial high-content free volume annihilates during creep,and strain hardening takes precedence over strain softening as the prevailing process during creep deformation,leading to a superior creep performance in extremely rejuvenated MGs.

关键词： Metallic glass Energy state Rejuvenation Creep Strain-hardening

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Nanostructured lubricant additives for titanium alloy:Lubrication by the solid-liquid interface with Coulomb repulsion

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friction 2024年第7期12卷 1564-1579页

作者： Linlin duan Dan JIA Jian LI Jianfang LIU haitao duan State Key Laboratory of Special Surface Protection Materials and Application Technology Wuhan Research Institute of Materials ProtectionWuhan 430030China hubei Longzhong Laboratory Xiangyang 441000China College of Life Science and Technology Wuhan Polytechnic UniversityWuhan 430030China

In this work,the advantage of Coulomb repulsion in the intermolecular forces experienced by molecules on the solid–liquid nanosized contact interface is taken,and the superior friction-reducing property of Cu_(3)(PO_(4))2·3h_(2)O(CuP)oil-based additives has been confirmed for titanium alloy.Three-dimensional(3D)CuP nanoflowers(CuP-fs)with a strong capillary absorption effect are prepared to achieve the homogeneous mixing of solid CuP and lubricating oil.Lubrication by CuP-fs additives for titanium alloy,friction coefficient(COf)can be reduced by 73.68%,and wear rate(WR)reduced by 99.69%.It is demonstrated that the extraordinary friction-reducing property is due to the repulsive solid–liquid interface with low viscous shear force originating from Coulomb repulsion between polar water molecules in CuP and non-polar oil molecules.however,any steric hindrance or connection between this repulsive solid–liquid interface will trigger the adhesion and increase the viscous shear force,for example,dispersant,hydrogen bondings,and shaky adsorbed water molecules.Besides,the lamellar thickness of CuP and the molecular size of lubricant both have a great influence on tribological properties.here the lubrication mechanism based on interface Coulomb repulsion is proposed that may help broaden the scope of the exploration in low-friction nanomaterial design and new lubricant systems.

关键词： lubrication nanomaterial additive solid-liquid interface wear

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On hamiltonian Property of Cayley Digraphs

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 547-556页

作者： fang duan Qiong-xiang hUANG School of Mathematics Science Xinjiang Normal UniversityUrumqi 830017China College of Mathematics and Systems Science Xinjiang UniversityUrumqi 830017China

Let G be a finite group generated by S and C(G,S) the Cayley digraphs of G with connection set S.In this paper,we give some sufficient conditions for the existence of hamiltonian circuit in C(G,S),where G=Zm×h is a semiproduct of Zmby a subgroup h of G.In particular,if m is a prime,then the Cayley digraph of G has a hamiltonian circuit unless G=Zm×h.In addition,we introduce a new digraph operation,called φ-semiproduct of Γ1by Γ2and denoted by Γ1×Γ_φΓ2,in terms of mapping φ:V(Γ2)→{1,-1}.furthermore we prove that C(Zm,{a})×_φ C(h,S) is also a Cayley digraph if φ is a homomorphism from h to{1,-1} ≤ Zm~*,which produces some classes of Cayley digraphs that have hamiltonian circuits.

关键词： Cayley digraphs hamiltonian circuit external semidirect product

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Efficient Direct Decomposition of NO over La_(0.8)A_(0.2)NiO_(3)(A=K, Ba, Y) Catalysts under Microwave Irradiation

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 17-23页

作者：王浩 ZhAO Zijian duan Xinghui ZhOU Shijia School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

La_(0.8)A_(0.2)NiO_(3) (A=K,Ba,Y) catalysts supported on the microwave-absorbing ceramic heating carrier were prepared by the sol-gel method.The crystalline phase and the catalytic activity of the La_(0.8)A_(0.2)NiO_(3)catalysts were characterized by XRD and h_(2) temperature-programmed reduction (TPR).The effects of reaction temperature,oxygen concentration,and gas flow rate on the direct decomposition of nitric oxide over the synthesized catalysts were studied under microwave irradiation (2.45 Ghz).The XRD results indicated that the La_(0.8)A_(0.2)NiO_(3) catalysts formed an ABO_(3) perovskite structure,and the h_(2)-TPR results revealed that the relative reducibility of the catalysts increased in the order of La_(0.8)K_(0.2)NiO_(3)>La_(0.8)Ba_(0.2)NiO_(3)>La_(0.8)Y_(0.2)Ni O_(3).Under microwave irradiation,the highest NO conversion amounted to 98.9%,which was obtained with the La_(0.8)K_(0.2)NiO_(3) catalyst at 400℃.The oxygen concentration did not inhibit the NO decomposition on the La_(0.8)A_(0.2)NiO_(3) catalysts,thus the N_(2) selectivity exceeded 99.8%under excess oxygen at 550℃.The NOconversion of the La_(0.8)A_(0.2)NiO_(3) catalysts decreased linearly with the increase in the gas flow rate.

关键词： microwave catalysis direct decomposition of NO microwave-absorbing heating ceramics perovskite catalyst

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Synergistic promotion of particulate matter reduction and production performance via adjusting electrochemical reactions in the zinc electrolysis industry

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frontiers of Environmental Science & Engineering 2024年第1期18卷 23-33页

作者： Zizhen Ma Jingkun Jiang Lei duan Jianguo Deng fuyuan Xu Zehui Li Linhua Jiang Ning duan School of Environmental and Municipal Engineering Qingdao University of TechnologyQingdao 266520China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of the EnvironmentTsinghua UniversityBeijing 100084China State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China School of Physics Peking UniversityBeijing 100871China

heavy particulate matter (PM) pollution and high energy consumption are the bottlenecks of hydrometallurgy, especially in the electrolysis process. Therefore, an urgent need is to explore PM reduction methods with production performance co-benefits. This study presents three PM reduction methods based on controlling operating parameters, i.e., lowering electrolyte temperature, h2SO4 concentration, and current density of the cathode. The optimized conditions were also investigated using the response surface methodology to balance the PM reduction effect and Zn production. The results showed that lowering electrolyte temperature is the most efficient, with an 89.0% reduction in the PM generation flux (GfPM). Reducing h2SO4 concentration led to the minimum side effects on the current efficiency of Zn deposition (CEZn) or power consumption (PC). With the premise of non-deteriorating CEZn and PC, GfPM can be reduced by 86.3% at the optimal condition (electrolyte temperature = 295 K, h2SO4 = 110 g/L, current density = 373 A/m^(2)). In addition, the reduction mechanism was elucidated by comprehensively analyzing bubble characteristics, electrochemical reactions, and surface tension. Results showed that lower electrolyte temperature inhibited the oxygen evolution reaction (OER) and compressed gas volume. Lower h2SO4 concentration inhibited the hydrogen evolution reaction (hER) and reduced electrolyte surface tension. Lower current density inhibited both OER and hER by decreasing the reaction current. The inhibited gas evolutions reduced the microbubbles’ number and size, thereby reducing GfPM. These results may provide energy-efficient PM reduction methods and theoretical hints of exploring cleaner PM reduction approaches for industrial electrolysis.

关键词： Zinc electrolysis Particulate matter Energy consumption Operating parameters Bubble characteristic Electrochemical reaction

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Influences of chemical reactions on polysulfide reduction reaction process on promotor surface in Li-S batteries

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Nano Research 2024年第4期17卷 2712-2718页

作者： Yufeng Luo Zhenhan fang Zixin hong Shaorong duan haitao Liu hengcai Wu Qunqing Li Yuegang Zhang Shoushan fan Wenhui duan Jiaping Wang Tsinghua-foxconn Nanotechnology Research Center Tsinghua UniversityBeijing 100084China Department of Physics Tsinghua UniversityBeijing 100084China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100088China frontier Science Center for Quantum Information Tsinghua UniversityBeijing 100084China

Polar promotors have been proven effective in catalyzing the polysulfide(PS)reduction reaction(PSRR)process in lithium-sulfur(Li-S)batteries.however,the promotor surface tends to be poisoned due to the accumulation of insoluble discharging products of lithium disulfide(Li_(2)S_(2))and lithium sulfide(Li_(2)S)during Li-S battery operation.herein,we investigate the detailed PSRR mechanism on the surface of manganese sulfides(MnS)as a representative promoter by performing in-situ Raman mapping measurements.The catalytic ability of MnS enables thorough electrochemical reduction of PSs to Li_(2)S_(2) and Li_(2)S on the MnS surface.The generated Li_(2)S_(2) and Li_(2)S then adsorb the dissolved PSs via chemical reactions among sulfur species during the subsequent PSRR process.This phenomenon mitigates promotor poisoning and continuously improves the reversible capacity.Consequently,the assembled Li-S cell demonstrates excellent electrochemical performance after introducing a conductive interlayer containing a thin piece of carbon nanotube film and MnS promotors.

关键词： promotors polysulfides chemical reactions catalytic ability in-situ Raman measurements

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Kinetics and mechanism of propylene hydro-oxidation to acrolein on Au catalysts

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Nano Research 2024年第1期17卷 354-363页

作者： Wei Du Zhihua Zhang Nan Song Xuezhi duan Xinggui Zhou State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China

Propylene epoxidation by h_(2)and O_(2)to propylene oxide(PO)over the Au-Ti bifunctional catalysts,as an ideal reaction for PO production,has attracted great interest.Revealing the mechanism of acrolein formation is of great importance for understanding the mechanism of molecular oxygen activation and the formation of hydroperoxo species on the Au sites.here,we investigate the reaction mechanism of propylene oxidation to acrolein on the Au/uncalcined TS-1(Au/TS-1-B)catalyst through a combination of multiple characterization,h_(2)/D_(2)exchange,kinetics experiment,and modeling.The Ti sites are found to be non-essential to acrolein formation.Moreover,the acrolein formation on the Au/TS-1-B catalyst is confirmed to be promoted by h_(2)through hydroperoxo species formation,which includes two main steps:propylene dehydrogenation to*C_(3)h_(5)with the aid of*OOh species,and*C_(3)h_(5)oxidation by*OOh to acrolein.The latter step is determined to be the rate-determining step because the corresponding kinetics model gives the best description for experimental results.This work not only provides kinetics insights for the propylene hydro-oxidation to acrolein on the Au-Ti bifunctional catalysts,but also facilitates the rational design of Au catalysts with high activity and selectivity in the direct propylene epoxidation with h_(2)and O_(2).

关键词： kinetics mechanism gold acrolein hydro-oxidation

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Crystalline-amorphous M@MNx（M=Co,fe,Ni）encapsulated in nitrogen-doped carbon for enhanced efficient and durable hydrogen evolution reaction

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Rare Metals 2024年第4期43卷 1547-1556页

作者： Yang Yang Xiao-Chuan duan Shao-hui Guo Xian-Ming Zhang College of Materials Science and Engineering College of ChemistryKey Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of Technology

Developing earth-abundant electrocatalysts for hydrogen evolution reaction（hER） is important for the sustainable energy economy.herein,efficient and stable heterocatalysts consisting of crystalline-amorphous M@MNx（M=Co,fe,Ni） encapsulated in N-doped carbon layers supported with N-doped graphene sheets（denoted as M@MNx@NC-NG） are synthesized by facile hydrothermal reaction and nitridation process.During the nitriding process,metal ions in M（tzbc）2（h2O）4(tzbc=4-（1h-1,2,4-triazol-1-yl） benzoic acid) complexes are reduced to crystalline M cores,accompanied by the formation of amorphous MNxshells;the tzbc ligands are insitu carbonized to form outermost N-doped carbon（NC）layers that connect with inner MNxvia M-N-C motifs inherited from the complex precursors and inhibit the transition of MNxfrom amorphous to crystalline phase.The Co@CoNx@NC-NG catalyst exhibits excellent hER activity with small overpotentials of 45 and 64 mV at a cathode current density of 10 mA·cm-2and low Tafel slopes of 40 and 85 mV·dec-1in 0.5 mol·L-1h2SO4and1.0 mol·L-1KOh electrolytes,respectively.The Co@CoNx@NC-NG retains 97% of the initial overpotential after 100,000 s in both acidic and alkaline media.Such outstanding hER performance originates from the crystalline-amorphous Co@CoNxthat redistributes electrons around the heterointerfaces,facilitating the conversion process of h+/h2O to hydrogen and thereby promoting hER kinetics.The outermost NC layers serve as the armor of Co@CoNx,and graphene nanosheets act as carriers of egg-like Co@CoNx@NC and conduction paths for electron shuttles,ensuring stable and continuous electrocatalytic hydrogen production.

关键词： hydrogen evolution reaction Electrocatalysts Iron group metals heterojunction Crystalline-amorphous structure

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BrrTCP4b interacts with BrrTTG1 to suppress the development of trichomes in Brassica rapa var. rapa

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Plant Diversity 2024年第3期46卷 416-420页

作者： Cheng Li Li Zhang hefan Li Yuanwen duan Xuemei Wen Yongping Yang Xudong Sun The Germplasm Bank of Wild Species Yunnan Key Laboratory of Crop Wild Relatives OmicsInstitute of Tibetan Plateau Research at KunmingKunming Institute of BotanyChinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences BeijingChina Tibet Plateau Institute of Biology Lhasa 850001TibetChina

The number of trichomes significantly increased in CRISPR/Cas9-edited BrrTCP4b turnip(Brassica rapa var.rapa)plants.however,the underlying molecular mechanism remains to be uncovered.In this study,we performed the Y2h screen using BrrTCP4b as the bait,which unveiled an interaction between BrrTCP4b and BrrTTG1,a pivotal WD40-repeat protein transcription factor in the MYB-bhLh-WD40(MBW)complex.This physical interaction was further validated through bimolecular luciferase complementation and co-immunoprecipitation.furthermore,it was found that the interaction between BrrTCP4b and BrrTTG1 could inhibit the activity of MBW complex,resulting in decreased expression of BrrGL2,a positive regulator of trichomes development.In contrast,AtTCP4 is known to regulate trichomes development by interacting with AtGL3 in Arabidopsis thaliana.Overall,this study revealed that BrrTCP4b is involved in trichome development by interacting with BrrTTG1 in turnip,indicating a divergence from the mechanisms observed in model plant A.thaliana.The findings contribute to our understanding of the regulatory mechanisms governing trichome development in the non-model plants turnip.

关键词： TCP transcription factor MBW complex Trichome development Turnip

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