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Anisotropy of the Wear Behavior for Carbon Nanotube-Reinforced 6061Al Composites

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Acta Metallurgica Sinica(English letters) 2023年第5期36卷 814-826页

作者： x.N.li J.F.zhang W.H.xue K.Ma P.y.li z.y.liu B.l.xiao d.R.Ni q.z.Wang d.Wang z.y.Ma School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

Carbon nanotube(CNT)-reinforced 6061Al(CNT/6061Al)composites with directionally aligned CNT were fabricated,and their wear behavior was *** results indicate that the wear properties of CNT/6061Al composites exhibited a significant anisotropy.A certain CNT concentrations(1 wt%and 2 wt%)could effectively improve the wear resistance of CNT/6061Al composites along the CNT circumferential and CNT radial directions for the load transfer,grain refinement and self-lubrication effect of *** Brass{011}and{112}textures inhibited the load transfer effect of CNT along the CNT radial direction,resulting in a better wear resistance along CNT circumferential direction than CNT radial *** the CNT axial direction,the weak deformability of composites caused by the intensifyingfiber texture was the main reasons for the poor wear resistance of CNT/6061Al composites with increasing CNT concentration.

关键词： Carbon nanotube Metal matrix composite Wear Anisotropy

quantized Conductance of Majorana zero Mode in the Vortex of the Topological Superconductor(li_(0.84)Fe_(0.16))OHFeSe

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Chinese Physics letters 2019年第5期36卷 90-97页

作者： C.Chen q.liu T.z.zhang d.li P.P.Shen x.l.dong z.-x.zhao T.zhang d.l.Feng State Key laboratory of Surface Physics and department of Physics Fudan UniversityShanghai 200433 Collaborative Innovation Center of Advanced Microstructures Nanjing 210093 Science and Technology on Surface Physics and Chemistry laboratory Mianyang 621908 National laboratory of Superconductivity Institute of PhysicsChinese Academy of SciencesBeijing 100190 Hefei National laboratory for Physical Science at Microscale CAS Center for Excellence in Quantum Information and Quantum Physicsand Department of PhysicsUniversity of Science and Technology of ChinaHefei 230026

The Major ana zero mode(MzM), which manifests as an exotic neutral excitation in superconductors, is the building block of topological quantum computing. It has recently been found in the vortices of several iron-based superconductors as a zero-bias conductance peak in tunneling spectroscopy. In particular, a clean and robust MzM has been observed in the cores of free vortices in(li_(0.84)Fe_(0.16))OHFeSe. Here using scanning tunneling spectroscopy, we demonstrate that Major ana-induced resonant Andreev reflection occurs between the STM tip and this zero-bias bound state,and consequently, the conductance at zero bias is quantized as 2e^2/h. Our results present a hallmark signature of the MzM in the vortex of an intrinsic topological superconductor, together with its intriguing behavior.

关键词： OHFeSe quantized Conductance of Majorana zero Mode in the Vortex of the Topological Superconductor MzM li STM Fe

Effect of water injection on the cavitation control:experiments on a NACA66(MOd)hydrofoil

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Acta Mechanica Sinica 2020年第5期36卷 999-1017,I0001页

作者： W.Wang T.Tang q.d.zhang x.F.Wang z.y.An T.H.Tong z.J.li School of Energy and Power Engineering Dalian University of TechnologyDalian 116024China Key laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of EducationDalian University of TechnologyDalian 116024China

The objective of this work is to investigate experimentally controlling cavitating flow over NACA66(MOd)hydrofoils by means of an active water injection along its suction *** continuous water vertically jets out of the chamber inside the hydrofoil through evenly distributed surface *** were carried out in cavitation water *** high-speed visualization technology and the particle image velocimetry(PIV)system to study the sheetlcloud cavity *** studied the effects of this active control on cavity evolution with four kinds of jet flow at two different jet *** analyzed the effect of water injection on the mechanism of the cavitating flow *** results were all compared with that for the original hydrofoil without jet and show that the active jet can effectively suppress the sheet/cloud cavitation characterized by shrinking the attached cavity size and breaking the large-scaled cloud sheding vortex cavity into small-scaled *** optimum effectiveness of cavitation suppression is affected by the jet flow rates and jet *** water injection at flow rate coefficient 0.0245 with the jet position of 0.45C reduces the maximum sheet cavity length by 79.4%and the cavity shedding is diminished completely,which gives the most superior effect of sheet cavitation *** jet blocks the re-entrant jet moving upstream and weakens the power of re-entrant jet and thus restrains the cavitation development effectively and stabilizes the flow field.

关键词： Cavitation active control Sheet/cloud cavitation.Water injection Re-entrant jet

Efficient Synthesis of Optically Active Alcohols

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复旦学报（自然科学版） 2005年第5期44卷 672-673页

作者： J.S. Chen z.R. dong y.y. li B.z. li y. xing W.y. Shen G. Chen x.q. zhang J.x. Gao State Key laboratory of Physical Chemistry of Solid Surfaces Deparment of ChemistryXiamen University Xiamen 361005 China

Optically active secondary alcohols are versatile building blocks for synthesis of unnatural biological active compounds and functional materials. Therefore, study on efficient synthesis of optically active alcohols is becoming an important subject in synthetic organic chemistry. Catalytic asymmetric reduction of carbonyl compounds is a practical method to create chiral alcohols. For the past decades, a large number of catalytic methods have been developed to achieve this goal.

关键词：配合基酒精乙醇生物学接触反应

THE INTERFACE OF TERNARy-BORIdE-BASEd HARd ClAddING MATERIAl

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Acta Metallurgica Sinica(English letters) 2004年第1期17卷 47-50页

作者： y.G.Wang z.q.li d.zhang State Key laboratory of Metal Matrix Composites Shanghai Jiaotong UniversityShanghai 200030 ChinaMechanical Engineering DepartmentShandong University Jinan 250061 ChinaState Key Laboratory of Metal Matrix CompositesShanghai Jiaotong UniversityShanghai 200030China

The interfacial microstructure of ternary-boride-based hard cladding material (yF-2) has been studied using scanning electron microanalyser (SEM), x-ray diffraction (xRd) and energy disperse spectroscopy (EdS). Results show that there are chemical reactions and elements diffusion in the interfacial zone, which make the interface bonding well and bonding strength ideal at the interface. The results gotten by studying of crack produced by Vickers indentation technique in the interfacial zone show that it is difficult to produce crack in the interface, the crack length in the cladding layer is longer than that to the interface, the crack which propagate to the interface stops at the interface rather than propagates along the interface. This suggests negligible residual stresses have developed because of thermal expansion mismatch. The bonding strength of the interface is 550MPa, which has been gotten by cutting test. The result gotten by analyzing the fracture surface shows that the fracture occurs at the side of cladding layer, which confirms that the bonding strength at the interface is higher than that in the cladding layer.

关键词： ternary boride cladding material interface micro structure

PICOTEES:a privacy-preserving online service of phenotype exploration for genetic-diagnostic variants from Chinese children cohorts

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Journal of Genetics and Genomics 2024年第2期51卷 243-251页

作者： xinran dong yulan lu lanting Guo Chuan li qi Ni Bingbing Wu Huijun Wang lin yang Songyang Wu qi Sun Hao zheng Wenhao zhou Shuang Wang Center for Molecular Medicine Children's Hospital of Fudan UniversityShanghai 201102China Key laboratory of Birth defects Children's Hospital of Fudan UniversityShanghai 201102China department of Bioinformatics Hangzhou Nuowei Information Technology Co.LtdHangzhouZhejiang 310000China The Third Research Institute of the Ministry of Public Security Shanghai 200031China xiamen Campus of Children's Hospital of Fudan University XiamenFujian 361006China Institutes for Systems Genetics West China HospitalChengduSichuan 610041China Shanghai Putuo People's Hospital Tongji UniversityShanghai 200060China

The growth in biomedical data resources has raised potential privacy concerns and risks of genetic information leakage. For instance, exome sequencing aids clinical decisions by comparing data through web services, but it requires significant trust between users and providers. To alleviate privacy concerns, the most commonly used strategy is to anonymize sensitive data. Unfortunately, studies have shown that anonymization is insufficient to protect against reidentification attacks. Recently, privacy-preserving technologies have been applied to preserve application utility while protecting the privacy of biomedical data. We present the PICOTEES framework, a privacy-preserving online service of phenotype exploration for genetic-diagnostic variants (https://***:3000/). PICOTEES enables privacy-preserving queries of the phenotype spectrum for a single variant by utilizing trusted execution environment technology, which can protect the privacy of the user's query information, backend models, and data, as well as the final results. We demonstrate the utility and performance of PICOTEES by exploring a bioinformatics dataset. The dataset is from a cohort containing 20,909 genetic testing patients with 3,152,508 variants from the Children's Hospital of Fudan University in China, dominated by the Chinese Han population (>99.9%). Our query results yield a large number of unreported diagnostic variants and previously reported pathogenicity.

关键词： Privacy protecti on Rare diseases in children Genetic testing Web system Trusted executi on envir onment

Unveiling anneal hardening in dilute Al-doped Al_(x)CoCrFeMnNi(x = 0,0.1) high-entropy alloys

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Journal of Materials Science & Technology 2021年第32期91卷 270-277页

作者： q.Cheng x.d.xu P.xie l.l.Han J.y.He x.q.li J.zhang z.T.li y.P.li B.liu T.G.Nieh M.W.Chen J.H.Chen Centre for High Resolution Electron Microscopy College of Materials Science and EngineeringHunan UniversityChangsha 410082China State Key laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Applied Materials Physics Department of Materials Science and EngineeringKTH-Royal Institute of TechnologyStockholm SE10044Sweden department of Materials Science and Engineering University of TennesseeKnoxvilleTN37996United States department of Materials Science and Engineering Johns Hopkins UniversityBaltimoreMD 21214USA

Anneal hardening has been one of the approaches to improve mechanical properties of solid solution alloys with the face-centered cubic(FCC) structure,whereby a considerable strengthening can be attained by annealing of cold-worked alloys below the recrystallization temperature(T_(rx)).Microscopically,this hardening effect has been ascribed to several mechanisms,*** segregation to defects(dislocation and stacking fault) and short-range chemical ordering,***,none of these mechanisms can well explain the anneal hardening recently observed in phase-pure and coarse-grained FCC-structured high-entropy alloys(HEAs).Here we report the observations,using high-resolution electron channeling contrast imaging and transmission electron microscopy,of profuse and stable dislocation substructures in a cold-rolled CoCrFeMnNi HEA subject to an annealing below T_(rx).The dislocation substructures are observed to be thermally stable up to T_(rx),which could arise from the chemical complexity of the high-entropy system where certain elemental diffusion retardation *** microstructure feature is marked.y.different from that of conventional dilute solid solution alloys,in which dislocation substructures gradually vanish by recovery during annealing,leading to a strength ***,dilute addition of 2 at.% Al leads to a reduction in both microhardness and.y.eld strength of the cold-rolled and subsequently annealed(≤500℃) *** Al induced softening effect,could be associated with the anisotropic formation of dislocation substructure,resulting from enhanced dislocation planar slip due to glide plane softening *** findings suggest that the strength of HEAs can be tailored through the anneal hardening effect from dislocation substructure strengthening.

关键词： Annealing hardening dislocation substructure strengthening High-entropy alloy Solid solution structure

On the mechanism of Si-promoted destabilization of TiC_(x)particles in Al alloys

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Journal of Materials Science & Technology 2023年第34期165卷 17-26页

作者： H.dong y.C.Guo y.z.Chen F.xia q.q.Guo q.Chen G.l.li J.y.zhao y.zhong J.P.li School of Materials and Chemical Engineering Xi’an Technological UniversityXi’an 710021China State Key lab.of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China School of Science Xi’an University of Science and TechnologyXi’an 710054China

TiC_(x)is an excellent composite strengthening particle and grain refiner for Al ***,the stability of TiC_(x)is poor when solute Si exists in Al alloy melts,which significantly depresses its strengthening and grain refining *** this work,the destabilization mechanisms of the TiC_(x)particles in Al-Si alloy melt with a composition of Al-7Si-7.5TiC were explored via experiments,first-principles calculations and thermodynamic *** experimental results show that Si atoms diffuse into TiC_(x)and Ti atoms are released into the Al melt to form a Ti-rich transition zone during the insulation of TiC_(x)in Al-Si melt,and the TiAlySiz and Al_(4)C_(3)phases are solidified in the Ti-rich zone and at Ti-rich zone/TiC_(x)interface,*** first principles calculations show that the low formation energy of C vacancies facilitates the rapid diffusion of Si atoms in TiC_(x),while the doping of Si atoms reduces the energy barrier of diffusion of Ti atoms in TiC_(x)and promotes the formation of Ti-rich *** thermodynamic calculations show that the wide crystallization temperature range of the destabilized product TiAlySiz phase is the key to continuous decomposition of TiC_(x)*** addition,the driving force of the main destabilization reaction of TiC_(x)in the Al-Si alloys is about 44 times higher than that in the Al alloys without Si *** indicates that the presence of solute Si remarkably promotes the subsequent decomposition process of TiC_(x)in the Al-Si alloy melts.

关键词： Al-Si alloy TiC_(x)particles destabilization First principles calculations Thermodynamics

Experimental methods for determination of mechanical behaviors of materials at high temperatures via the split Hopkinson bars

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Acta Mechanica Sinica 2020年第6期36卷 1275-1293,I0003页

作者： q.B.dou K.R.Wu T.Suo C.zhang x.Guo y.z.Guo W.G.Guo y.l.li School of Aeronautics Northwestern Polytechnical UniversityXi’an710072China Joint International Research laboratory of Impact dynamics and its Engineering Application Xi’an710072China Shaanxi Key laboratory of Impact dynamics and its Engineering Application Xi’an710072China State Key laboratory for Strength and Vibration of Mechanical Structures School of AerospaceXi’an Jiaotong UniversityXi’an710049China

Full understanding of the thermomechanical behaviors of materials at high strain rates and high temperatures are of great importance from not only scientific meaning but also practical value in engineering structure design and safety *** efforts have been made for abilities of operation the split Hopkinson bars,the most popular technique for experimental determination of mechanical behaviors of materials over the strain rates from 10^2 to 10^4 s^−1 over the past 70 years,at high temperatures since 1960s.A review of experiment work is presented in this paper to give an overview of the development of experimental techniques at high temperatures based on Hopkinson bar *** principles of the split Hopkinson bar requires the loading bars avoiding temperature gradient or keeping relatively low temperature when performing high temperature *** such as performing temperature gradient corrections,rapid heating or using special designed automatically assembled systems were proposed by researchers to enable the operation of the split Hopkinson bars at temperature as high as ***,to the application of high speed photographic technique for capturing the dynamic deformation process of the specimen in high temperature Hopkinson bar testing,some key issues of eliminating the strong thermal radiation induced lights oversaturation and de-blurring of images due to insufficient exposure at high temperature and high strain rate condition,as well as fabrication of high contrast speckle pattern for high temperature digital image correlation measurement were also *** technique can now enable the split Hopkinson bar testing to be performed at high temperature up to 1873 K under the loading conditions of compression or tension with the in situ observation and full field measurement of deformation as *** paper concludes with summaries of the most important achievements and highlighting of the prospects,trends and remaining challenge

关键词： Mechanical behaviors Split Hopkinson bar High strain rate High temperature