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Bio-Adaption between magnesium Alloy Stent and the Blood Vessel:A Review

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Journal of materials Science & Technology 2016年第9期32卷 815-826页

作者： Jun ma Department of Chemical Biological and BioengineeringNorth Carolina Agricultural and Technical State UniversityGreensboroNCUSA NSF Engineering Research Center-Revolutionizing Metallic Biomaterials North Carolina Agricultural and Technical State UniversityGreensboroNC USA

Biodegradable magnesium （Mg） alloy stents are the most promising next generation of bio-absorbable stents. In this article, we summarized the progresses on the in vitro studies, animal testing and clinical trials of biodegradable Mg alloy stents in the past decades. These exciting findings led us to propose the importance of the concept ＂bio-adaption＂ between the Mg alloy stent and the local tissue microenvironment after implantation. The healing responses of stented blood vessel can be generally described in three overlapping phases： inflammation, granulation and remodeling. The ideal bio-adaption of the Mg alloy stent, once implanted into the blood vessel, needs to be a reasonable function of the time and the space/dimension. First, a very slow degeneration of mechanical support is expected in the initial four months in order to provide sufficient mechanical support to the injured vessels. Although it is still arguable whether full mechanical support in stented lesions is mandatory during the first four months after implantation, it would certainly be a safety design parameter and a benchmark for regulatory evaluations based on the fact that there is insufficient human in vivo data available, especially the vessel wall mechanical properties during the healing/remodeling phase. Second, once the Mg alloy stent being degraded, the void space will be filled by the regenerated blood vessel tissues. The degradation of the Mg alloy stent should be 100% completed with no residues, and the degradation products （e.g., ions and hydrogen） will be helpful for the tissue reconstruction of the blood vessel. Toward this target, some future research perspectives are also discussed.

关键词： Mg stent Bio-adaptation Vessel Wound healing

Recent advances in room-temperature phosphorescent materials by manipulating intermolecular interactions

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Science China Chemistry 2023年第2期66卷 304-314页

作者： Liangwei ma Xiang ma Key Laboratory for Advance materials and Feringa Noble Prize Scientist Joint Research Centre Frontiers Science for Materiobiology and Dynamic ChemistrySchool of Chemistry and Molecular EngineeringEast China University of Science&TechnologyShanghai200237China

Metal-free room-temperature phosphorescence(RTP)materials have the characteristics of large Stokes shift,long lifetime,and triplet state *** exhibit application potential in various fields,such as bioimaging,computer display,sensor,and anticounterfeiting and have drawn much research *** work showed that manipulating intermolecular interactions(e.g.,crystallization,polymerization,and rigid matrix)and host-guest assembly to restrain nonradiative transitions and isolate phosphor from oxygen as much as possible is a feasible way to obtain various types of efficient RTP *** some cases,intermolecular interactions also facilitated RTP emission by regulating the triplet *** the other hand,heavy atoms(Br,I,etc.),heteroatoms(N,O,S,etc.),or carbonyls were introduced to the molecular skeleton through molecular engineering to enhance intersystem crossing,which is important for populating the triplet *** comprehensively using the aforesaid strategies,great progress has been made for RTP *** this mini-review,we summarized recent advances in organic RTP materials based on manipulating intermolecular *** host-guest assembly,hydrogen-bond assembly,energy transfer process,and exciplex emission system-based RTP materials were well *** summary,the current challenges and prospects for development in this field were presented.

关键词： room-temperature phosphorescence host-guest assembly energy transfer exciplex supermolecule

A dual-beam piezo-magneto-elastic wake-induced vibration energy harvesting system for high-performance wind energy harvesting

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Science China(Technological Sciences) 2024年第1期67卷 221-239页

作者： ma XiaoQing ZHANg Hang maRgIELEWICZ Jerzy gĄSKA Damian WOLSZCZAK Piotr LITAK grzegorz ZHOU ShengXi School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Research&Development Institute in Shenzhen Northwestern Polytechnical UniversityShenzhen 518057China Faculty of Transport and Aviation Engineering Silesian University of TechnologyKrasińskiego 8Katowice 40-019Poland Department of Automation Lublin University of TechnologyNadbystrzycka 36Lublin 20-618Poland

Wind-induced vibration energy harvesting has a great potential for utilizing wind energy to supply power for low-powered *** improve the working performance of energy harvesters effectively,a suitable structural design is *** paper proposes a dual-beam piezo-magneto-elastic wake-induced vibration energy harvesting system to enhance the functional performance of aeroelastic energy harvesters in environments with variable wind *** system contains two piezoelectric beams coupled by magnets(forming upstream and downstream energy harvesters),and each beam is attached with a foam cylinder.A corresponding dynamic model is provided,and output characteristics are obtained at different wind *** and experimental verification indicate that both upstream and downstream energy harvesters can realize efficient energy *** the wind speed exceeds a certain critical value,the amplitudes of the system’s displacement and voltage are *** wind speed threshold value is approximately 1.25 m/*** the wind speed and magnet spacing are 10.2 m/s and 20 mm,respectively,the output power of the system reaches 4.9×10^(−4)***,the wind speed threshold value of the proposed system can be adjusted by an equivalent nonlinear restoring force.

关键词： dual-beam structure piezoelectric energy harvester theoretical model nonlinear dynamics

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New Year's greeting and overview of World Journal of Cardiology in 2021

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World Journal of Cardiology 2021年第2期13卷 38-41页

作者： Ya-Juan ma Ramdas g Pai Editorial Office Baishideng Publishing Group IncPleasantonCA 94566United States University of California Riverside School of Medicine St Bernardines Medical CenterRiversideCA 92507United States

On behalf of the Editorial Office of World Journal of Cardiology(WJC),we extend our sincere gratitude to our authors,readers,Editorial Board members,and peer reviewers,thanking each and every one for their contributions to WJC in 2020 and with wishes for a Happy New *** was the collective support of all authors,Editorial Board members,peer reviewers and staff of the Editorial Office that allowed the Baishideng Publishing group *** carry out successfully the complete peer review,editing and publishing processes for WJC in *** have now analyzed the metric data of WJC's manuscripts that were submitted and published in 2020,the peer review of manuscripts in 2020,the invited manuscripts for 2021 and the Editorial Board members’composition and *** a global academic journal in cardiology,the findings from such will facilitate greater productivity and more efficient collaborative efforts to raise the academic rank of WJC in *** enthusiastically anticipate WJC’s contributions to promote further cardiology research sharing and exchange in 2021.

关键词： World Journal of Cardiology Baishideng Editorial board members Cardiology New Year's message Academic rank

Experimental study on prediction model of wet gas pressure drop across single-orifice plate in horizontal pipes in the low gas phase Froude number region

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Chinese Journal of Chemical Engineering 2022年第6期35卷 63-72页

作者： Youfang ma Youfu ma Junfu Lyu Weiye Liu Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering School of Energy and Power EngineeringUniversity of Shanghai for Science and TechnologyShanghai 200093China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Energy and Power EngineeringTsinghua UniversityBeijing 100084China

The pressure drop prediction of wet gas across single-orifice plate in horizontal pipes had been solved satisfactorily under an annular-mist flow in the upstream of orifice ***,this pressure drop prediction is still not clearly determined when the upstream is in an intermittent flow or stratified flow,which is corresponding to a region of low Frg(gas phase Froude number)in the flow pattern map of wet *** this study,the wet gas pressure drop across a single-orifice plate was experimentally investigated in the low Frg *** the experiment,the flow pattern transition in the downstream of single-orifice plates,as well as the effects of Frg and FrL(liquid phase Froude number)on Ug(gas phase multiplier),were determined and compared when the upstream is in the flow pattern transition and the stratified flow region,*** performances were examined on the available pressure drop *** was found that no model could be capable of jointly predicting the wet gas pressure drop in the low Frg region with an acceptable *** a new method of correlating Frg and FrL simultaneously,new correlations were proposed for the low Frg *** which the modified Chisholm model shows the best prediction accuracies,with the prediction deviations of Ug being within 7%and 3%when the upstream is in flow pattern transition and stratified flow region,respectively.

关键词： gas-liquid flow Two-phase flow Wet gas Orifice plate Pressure drop Model

Effect of Rotation Rate on Microstructure and Mechanical Properties of Friction Stir Spot Welded DP780 Steel

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Journal of materials Science & Technology 2016年第4期32卷 326-332页

作者： g.M.Xie H.B.Cui Z.A.Luo W.Yu J.ma g.D.Wang State Key Laboratory of Rolling and Automation Northeastern University

DP780 steel sheets consisting of ferrite and martensite were successfully friction stir spot welded （FSSW） at the rotation rates of 500 to 1500 r/min using a W-Re alloy tool, The effect of rotation rate on micro- structure and mechanical properties of the FSSW DP780 was investigated. The peak temperatures in the welds at various rotation rates were identified to be above A3 temperature. FSSW caused the dynamic recrystallization in the stir zone （SZ）, thereby producing the fine equiaxed grain structures. At the higher rotation rates of≥1000 r/min, a full martensitic structure was observed throughout the SZs, whereas at the lower rotation rate of 500 r/min, the SZ consisted of a fine dual phase structure of ferrite and mar- tensite due to the action of deformation induced ferrite transformation. The maximum average failure load as high as 18.2 kN was obtained at the rotation rate of 1000 r/min and the fracture occurred at the thinned upper sheet.

关键词： Friction stir spot weldingDual phase steelMicrostructureDeformation induced ferritetransformationMechanical property

Effect of alloying elements on mechanical properties in Cu-15%Cr in-situ composites

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中国有色金属学会会刊：英文版 2004年第2期14卷 284-290页

作者： H.g.Suzuki J.ma K.Mihara S.Sakai S.Sun Japan Society for Promotion of Science Department of Materials Science and EngineeringFurukawa Electric COFurukawa Electric CONational Institute for Materials Science 4-1-8 Hon-machi Kawaguchi332-0012 JapanDepartment of Materials Science and EngineeringTsinghua UniversityBeijing 100084 China Tsinghua UniversityBeijing 100084China LTDNikko 321-0014JapanLTDNikko 321-0014JapanTsukuba 305-0047Japan

The effects of alloying elements on the mechanical properties as well as electrical conductivity in Cu-15%Cr(mass fraction) in-situ composites were systematically studied and high strength and high electrical conductive Cu base in-situ composites have been developed. The best combination is the addition of 0.1% to 0.2% Zr, Ti, or Sn in Cu-15%Cr in-situ composite, thermomechanical treatment to refine the microstructure and optimizing the precipitation of second phase. The strength is controlled by high density of dislocations in the Cu matrix, the lamellar spacing of the second phase, and the fine Cr precipitates. The aging treatment to reduce solute atoms has a beneficial effect on the increase of electrical conductivity. The addition of Zr, or Ti of about 0.15% to 0.2% promotes the precipitation of Cr particles.

关键词： CuCr合金铜合金内生复合材料机械性能合金化电导率

An Inverse Approach for Extracting Elastic-plastic Properties of Thin Films from Small Scale Sharp Indentation

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Journal of materials Science & Technology 2012年第7期28卷 626-635页

作者： Z.S. ma Y.C. Zhou S.g. Long C.S. Lu Key Laboratory of Low Dimensional materials ~ Application Technology of Ministry of Education Xiangtan Uni-versity Xiangtan 411105 China Faculty of materials Optoelectronics and Physics Xiangtan University Xiangtan 411105 China Department of Mechanical Engineering Curtin University of Technology Perth WA 6845 Australia

An inverse method for extracting the elastic-plastic properties of metallic thin films from instrumented sharp indentation has been proposed in terms of dimensional analysis and finite element modeling. A wide range of materials with different elastic modulus, yield strength, and strain-hardening exponent were *** to the Nix-gao model for the depth dependence of hardness H,the relationship between elastic modulus E and indentation depth h can be expressed as By combiningthese two formulas, we find that there is a relationship between yield stress and indentation depth h：where σyO is the yield strength associated with the strain-hardening exponent n, the true hardness Ho and the true elastic modulus *** constant, whichis only related to n, and hH and hE are characteristic lengths for hardness and elastic modulus. The results obtained from inverse analysis show that the elastic-plastic properties of thin films can be uniquely extracted from the solution of this relationship when the indentation size effect has to be taken into account.

关键词： Indentation Elastic-plastic properties Metal thin films Inverse analysis

Tensile Strength and Electrical Conductivity of Carbon Nanotube Reinforced Aluminum matrix Composites Fabricated by Powder Metallurgy Combined with Friction Stir Processing

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Journal of materials Science & Technology 2014年第7期30卷 649-655页

作者： Z.Y.Liu B.L.Xiao W.g.Wang Z.Y.ma Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of Sciences Dalian University of Technology Liaoning Shihua University

A route combining powder metallurgy and subsequent friction stir processing was utilized to fabricate carbon nanotube （CNT） reinforced AI （CNT/AI） and 6061AI （CNT/6061AI） composites. Microstructural observations indicated that CNTs were uniformly dispersed in the matrix in both CNT/AI and CNT/6061AI composites. Mg and Si elements tended to segregate at CNT-AI interfaces in the CNT/6061AI composite during artificial aging treatment. The tensile properties of both the AI and 6061AI were increased by CNT incorporation. The electrical conductivity of CNT/AI was decreased by CNT addition, while CNT/6061AI exhibited an increase in electrical conductivity due to the Mg and Si segregation.

关键词： Carbon nanotubes Metal matrix composites Mechanical properties Electrical properties Friction stir processing