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THERMODYNAMIC EXPLANATION OF LEADING PHASE IN PEARLITE TRANSFORMATION

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Acta Metallurgica Sinica(English Letters) 1997年第2期10卷 145-150页

作者： liu, X.j. Guangdong Industrial Univ Guangzhou China

In this paper a concept of 'leading probability' is presented. The difference in the leading probability between ferrite and cementite depends mainly upon the difference between their driving forces at the beginning of precipitation. The results of theromdynamic calculations showed that the leading probability of cementite increased with the increase of carbon concentration of austenite, and the decrease in transformation temperature was favourable to cementite's being the leading nucleus during pearlite transformation.

关键词： leading phase pearlite transformation decomposition of austenite

Effects of the Reversely Rotating Assisted Shoulder on Microstructures During the Reverse Dual-rotation Friction Stir Welding

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journal of Materials Science & Technology 2015年第4期31卷 375-383页

作者： j.Q.Li H.j.liu State Key Laboratory of Advanced Welding and joining Harbin Institute of Technology Capital Aerospace Machinery Company

The reverse dual-rotation friction stir welding(RDR-FSW) has the capability to adjust the heat generation because of the separately designed tool shoulder and tool *** welding torque exerted on the workpiece by the reversely rotating shoulder is opposite to that exerted by the rotating tool pin,so the total welding torque is reduced,which is beneficial to reducing the clamping requirement of *** the present paper,a RDR-FSW joint was welded in a condition similar to the optimal welding condition of conventional FSW,and microstructures in various zones were investigated by comparison,aiming to highlight effects of the reversely rotating assisted *** to the heat conduction of the middle cylinder and the bottom end cover on which the assisted shoulder was machined,the thermal effect of RDR-FSW was smaller than that of the conventional ***,the effect of assisted shoulder on the plastic flow or deformation of material or was constrained in a thin layer near the weld top surface,and thus the flow of material especially along the thickness direction was clearly decreased in the *** the heat-affected zone(HAZ),the precipitate coarsening was the main evolution and was completed through the dissolution of small precipitates and the continuous growth of large *** contrast,the dissolution degree of precipitates increased significantly in the thermomechanically affected zone(TMAZ),and a small amount of original meta-stable precipitates transformed to block-shaped stable *** evolutions in the shoulder affected zone(SAZ)and the weld nugget zone were similar,*** majority of original meta-stable precipitates dissolved into the matrix and the remainder transformed to stable precipitates,though the dissolution degree was greater in the *** with the conventional FSW joint,the coarsening degrees of precipitates in the HAZ and TMAZ of RDR-FSW joint were much smaller,as well as the dissolution degrees of p

关键词： Friction stir welding Reverse dual-rotation fricti

Compressive property and energy absorption characteristic of interconnected porous Mg-Zn-Y alloys with adjusting Y addition

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journal of Magnesium and Alloys 2024年第1期12卷 171-185页

作者： j.A.liu S.j.liu B.Wang W.B.Sun X.j.liu Z.W.Han College of Materials Science and Engineering Key Laboratory of Automobile Materials(Ministry of Education)Jilin UniversityChangchun 130022PR China Key Laboratory of Bionic Engineering(Ministry of Education) College of Biological and Agricultural EngineeringJilin UniversityChangchun130022PR China Weihai Institute for Bionics-jilin University Weihai 264205PR China

In this study,interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption *** characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second *** tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous *** experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second *** the Y content increases,different Mg-Zn-Y ternary phases appear:I-phase(Mg_(3)Zn_(6)Y),W-phase(Mg_(3)Zn_(3)Y_(2)),and LPSO phase(Mg_(12)ZnY).When the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 Mj/m^(3)to 10.97 Mj/m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second ***,the average energy absorption efficiency is independent of the Y *** addition,the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing *** compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the *** deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.

关键词： Porous magnesium Rare earth elements Microstructure Compressive behavior Energy absorption characteristic

On the ground in Western Africa： from the outbreak to the elapse of Ebola

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Protein & Cell 2016年第9期7卷 621-623页

作者： William j. liu National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and Prevention Beijing China

I was sitting in the chair of the airplane back to Beijing when I started writing the memoirs to recollect my three journeys to Western Africa. All of the trips were related to the Ebola epidemic and covered different stages, from the outbreak peak to the post-Ebola era. Each journey was taken for a different task, but all of them represented the urgent and specific support from the Chinese Center for Disease Control and Prevention （China CDC） during the Ebola epidemic in Western African.

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The triphibious warfare against viruses

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Science China(Life Sciences) 2017年第12期60卷 1295-1298页

作者： William j.liu Di liu Key Laboratory of Medical Virology and Viral Diseases Ministry of Health of People's Republic of China National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and Prevention CAS Key Laboratory for Pathogenic Microbiology and Immunology Institute of Microbiology Chinese Academy of Sciences Computational Virology Group CAS Key Laboratory of Special Pathogens and Biosafety Wuhan Institute of Virology Chinese Academy of Sciences

Despite the long journey undertaken by mankind to confront the diseases caused by viruses,people were unaware of the existence of viruses until the closing years of the 19th century,when the Russian biologist Dmitri Ivanovsky demonstrated that tobacco plants could be infected by a toxin smaller than bacteria,followed by which the Dutch microbiologist Martinus Beijerinck termed the toxin as a contagium vivum fluidum （soluble living germ） and re-introduced the word ＂virus＂（derived from the Latin word ＂virus＂ meaning poison; the modern meaning is an ＂agent that causes infectious disease＂ that was first recorded in 1728）.

关键词： The triphibious warfare viruses

A Tale of Two Cities:From Influenza HxNy to SARS-CoV-z

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China CDC weekly 2021年第49期3卷 1052-1056页

作者： William j.liu Shelan liu Chinese National Influenza Center(CNIC) National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijingChina Department of Infectious Diseases Zhejiang Provincial Center for Disease Control and PreventionHangzhouZhejiangChina Key Laboratory of Vaccine Prevention and Control of Infectious Disease of Zhejiang ProvinceHangzhouZhejiangChina.

THE COMMON FEATURES OF VIRUSES WITH PANDEMIC POTENTIAL In the past hundred years,human population expansion and globalization have changed the pattern of human-nature interactions and accelerated the emergence and spread of novel infectious diseases(1).Humans have experienced a long list of microbial threats to health,of which,70%are believed to be from animal reservoirs(2),such as severe acute respiratory syndrome coronavirus(SARS-CoV).

关键词： acute diseases respiratory

Filters and structure of lattice implication algebra

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Chinese Science Bulletin 1997年第18期42卷 1517-1520页

作者： liu, j Xu, Y Department of Applied Mathematics Southwest Jiaotong University Chengdu China

IN order to research the logical system whose propositional value is given in a lattice from

关键词： lattice implication algebra filter generated filter.

Enhanced helium ion irradiation tolerance in a Fe-Co-Ni-Cr-Al-Ti high-entropy alloy with L12 nanoparticles

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journal of Materials Science & Technology 2023年第12期143卷 169-177页

作者： Y.L.Zhao F.L.Meng T.Yang j.H.Luan S.F.liu G.M.Yeli W.T.Lin W.H.liu X.j.liu C.T.liu j.j.Kai School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Materials Science and Engineering Mechanical Behavior Division of Shenyang National Laboratory for Materials ScienceCity University of Hong KongHong KongChina Department of Mechanical Engineering City University of Hong KongHong KongChina Institute of Nuclear&New Energy Technology Tsinghua UniversityBeijing 100084China

L12-strengthened high entropy alloys(HEAs)with excellent room and high-temperature mechanical prop-erties have been proposed as promising candidates as structural materials for advanced nuclear ***,knowledge about their radiation response is fairly *** the present work,a novel HEA with a high density of L12 nanoparticles was irradiated with He ion at 500°*** electron microscope(TEM)and atom probe tomography(APT)were employed to study the evolution of mi-crostructural stability and radiation-induced *** to the single-phase FeCoNiCr HEA,the main microstructural features were numerous large faulted dislocation loops and helium *** the irradiation resistance of the present L12-strengthened HEA is much improved in terms of reduced bubble size,which could be attributed to the considerable He trapping efficiency of the coherent pre-cipitate/matrix interface and the enhanced capability of the interface for damage elimination when the matrix channel width is *** analysis revealed that an inverse-Kirkendall-mechanism-dominated radiation-induced segregation(RIS)occurs around bubbles,where a significant Co enrichment and Ni de-pletion can be clearly *** addition,the competing dynamics of ballistic mixing and elemental clustering that raised from the irradiation-enhanced diffusion in a highly supersaturated matrix,along with the low precipitation nucleation barrier due to the small lattice misfit,lead to a dynamical pre-cipitation dissolution and re-precipitation appears under *** a promising phenomenon is expected to promote a potential self-healing effect and could in turn provide a sustainable irradiation tolerance over the operational lifetime of a reactor.

关键词： L12 nanoparticles High-entropy alloy Helium bubble Phase stability Radiation-induced segregation

THE　KINETIC　RESOLUTION　OF　1，1＇－BINAPHTHYL－2，2＇－DIYLPHOSPHORYL　CHLORIDE　WITH　OPTICALLY　PURE　AMINES

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Chinese Chemical Letters 1995年第11期6卷 959-960页

作者： Wang, M liu, SZ liu, j Hu, BF Beijing Agr Univ Dept Appl Chem Beijing 100094 Peoples R China

The reactions of 1.1'-binaphthyl-2,2'-diylphosphoryl chloride with optically pure amines give diastereoselective products with the de% from20% to 82%.

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