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Enhancing strength and ductility of AlSi10Mg fabricated by selective laser melting by tiB_(2)nanoparticles

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Journal of Materials Science & technology 2022年第14期109卷 254-266页

作者： Y.K.Xiao H.Chen z.Y.Bian t.t.Sun H.Ding Q.Yang Y.Wu Q.Lian z.Chen H.W.Wang State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China School of Materials Science&Engineering Shanghai Jiao Tong UniversityShanghai 200240China

In the metallic components fabricated by the emerging selective laser melting(SLM)technology,most strategies used for strengthening the materials sacrifice the ductility,leading to the so-called strengthductility *** the present study,we report that the strength and ductility of materials can be enhanced simultaneously by introducing nanoparticles,which can break the trade-off of the metallic *** the case of in-situ nano-tiB_(2)decorated AlSi10Mg composites,the introduced nanoparticles lead to columnar-to-equiaxed transition,grain refinement and texture *** increasing content of nanoparticles,the strength increases ***,the ductility first increases and then *** results show that the ductility is controlled by the competition between the crack-induced catastrophic fracture and ductile fracture associated with dislocation *** first increase of ductility is mainly attributed to the suppression of crack-induced catastrophic fracture when tiB_(2)nanoparticles *** the further increase of tiB_(2)nanoparticles,the subsequent decrease of ductility is mainly controlled by dislocation ***,the materials will exhibit the optimum strength and ductility combination in a certain range of tiB_(2)*** study clarifies the physical mechanism controlling ductility for nano-tiB_(2)decorated Al Si10Mg composites,which provides the insights for the design of structural materials.

关键词： Selective laser melting Aluminium matrix composites Ductility Mechanical behavior Dislocations Cracks

一种新型心血管疾病风险评估模型与四种国内外常见评估工具对高糖患者心血管疾病风险评估的比较研究

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中国全科医学 2024年第21期27卷 2646-2648页

作者：黄书玮周志衡冯天元刘莉邓光璞张艺旋朱宏南方医科大学公共卫生学院广东省广州市510515 南方医科大学南方医院广东省广州市510515 南方医科大学深圳坪山总医院广东省深圳市518118

心血管疾病(cardiovascular disease,CVD)严重危害我国居民的生命健康安全。高血压、糖尿病是发生CVD的常见危险因素,且继发CVD常是高血压和糖尿病患者(以下简称为高糖患者,指患有高血压或糖尿病其中一种或两种的患者)死亡结局的主要原... 详细信息

心血管疾病(cardiovascular disease,CVD)严重危害我国居民的生命健康安全。高血压、糖尿病是发生CVD的常见危险因素,且继发CVD常是高血压和糖尿病患者(以下简称为高糖患者,指患有高血压或糖尿病其中一种或两种的患者)死亡结局的主要原因,我国高糖患者基数庞大,因而糖尿病患者发生CVD的预防尤为重要^([1-2])。预防CVD的发生,需要及时识别高风险人群,以采取有效的生活方式和药物干预措施。

关键词：心血管疾病风险评估模型高血压糖尿病

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Embedding laser-generated Cdte nanocrystals into ultrathin znIn_(2)S_(4) nanosheets with sulfur vacancies for boosted photocatalytic H_(2) evolution

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Journal of Materials Science & technology 2023年第35期166卷 113-122页

作者： z.G.tai G.t.Sun X.H.zhang X.B.Yang t.Wang z.Y.Fang Q.Ye L.C.Jia H.Q.Wang State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518063China School of Materials Science and Engineering Shaanxi Normal UniversityXi’an 710119China

to suppress the inner charge recombination and inject vast electrons,Cdte nanocrystals are embedded into ultrathin znIn_(2)S_(4) nanosheets to construct znIn_(2)S_(4)/Cdte heterostructures,where the nanocrystals are generated by a laser irradiation *** optimal znIn_(2)S_(4)/Cdte heterojunction exhibits an excellent catalytic activity of 24.3 mmol/h/g,which is relatively high among the znIn_(2)S_(4)-based photocatalysts with-out noble *** enhancement is ascribed to a win-win mechanism of nanoscale heterojunctions and sulfur *** strong electron coupling effect,which is verified by density functional the-ory(DFt)calculations,impels the photo-generated electrons transfer from Cdte to znIn_(2)S_(4),boosting the charge ***,the sulfur vacancies existing in znIn_(2)S_(4) can capture photoelectrons and act as active sites,facilitating the H_(2) generation *** addition,the znIn_(2)S_(4) base and the znIn_(2)S_(4)/Cdte heterojunction also possess an evident photothermal effect and renewable cycle phenomena,enhancing the photocatalytic *** research provides new insights into the regulation of charge transfer through embedding nanocrystals.

关键词： Photocatalysis Hydrogen evolution Laser irradiation Heterostructure Sulfur vacancies

tHEOREtICAL PREDICtION OF tHE KINEtICS CURVES OFPEARLItIC tRANSFORMAtION IN HYPO-PROEUtECtOID StRUCtURAL StEELS

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Acta Metallurgica Sinica(English Letters) 1998年第3期11卷 215-224页

作者： z.G.Li H.B.Chang t.Y.Hsu z.Y.Xu X.Y.Ruan Shanghai Jiaotong Univ Shanghai China

Supposing carbon contents of ferrite phases in pearlite precipitating from austenite in multicomponent steel at temperature t and in Fe-C ystem at t' are the same the pearlite formation temperature diference, can be calculated from the FeX phase diagrams and the equilibrium temperature Al. Using tp and Fe-C binary thermodynamic model, the driving forces for phase transformation from austenite to pearlite in multicomponent steels have been successfully calculated. through the combination of simplified zener and Hillert's model for pearlite growth with Johnson-Mehl equation, using data from known ttt diagrams, the interfacial energy parameter and activation energy for pearlite formation can be determined and expressed as functions of chemical composition in steels by regression analysis. the calculated starting curves of pearlitic transformation in some commercial steels agree well with the experimental data.

关键词： pearlite formation temperature difference interfacial energy parameter activation enerpy for pearlite transformation,Johnson-Mehl equation

tHEOREtICAL PREDICtION OF PROEUtECtOID FERRItICtRANSFORMAtION IN HYPO-PROEUtECtOID StRUCtRAL StEELS

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Acta Metallurgica Sinica(English Letters) 1998年第3期11卷 207-214页

作者： H.B.Chang z.G.Li t.Y.Hsu z.Y.Xu X.Y.Ruan Shanghai technical Coll of Metallurgy Shanghai China

Proeutectoid ferrite with carbon content xo precipitating from austenite in a multicomponent steel at temperature t is supposed to be equivalent to proeutectoid ferrite with the same carbon content precipitating from austenite in Fe-C binary system at temperature t'.is described as the temperature difference of proeutectiod ferrite formation, and can be calculated from the Fe-X diagrams and the equilibrium temperature A3. By introducing tf and basing on the thermodynamic model for Fe-C binary alloy, the driving force for phase transformation from austenite to proeutectoid ferrite in multicomponent steels has been successfully calculated. through the Johnson-Mehl equation and using the data hem known ttt diagrams, the relationship between the chemical composition and the intedecial edenly packeter as well as activation energy for proeutectoid ferrite formation can be calculated. the starting curves of proeutectoid ferritic transformation calculated in this way in some hypo-proeutectoid structural steels agree well with the erperimental data.

关键词： proeutectoid ferrite formation temperature difference interfacial enerpy parameters activation energy for diffusion Johnson-Mehl equation

two-dimensional atomically thin Pt layers on MXenes: the role of electronic effects during catalytic dehydrogenation of ethane and propane

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Nano Research 2024年第3期17卷 1251-1258页

作者： zhe Li tobias K.Misicko Fan Yang Xiaopeng Liu zhenwei Wu Xiaoyang Gao tao Ma Jeffrey t.Miller Daniela S.Mainardi Collin D.Wick zhenhua zeng Yang Xiao Yue Wu Department of Chemical and Biological Engineering Iowa State University618 Bissell RoadAmesIA 50011USA Institute for Micromanufacturing Louisiana Tech University505 Tech DriveRustonLA 71272USA Davidson School of Chemical Engineering Purdue University480 Stadium Mall DriveWest LafayetteIN 47907USA Michigan Center for Materials Characterization University of Michigan2800 Plymouth RdAnn Arbor MI 48109USA College of Engineering and Science Louisiana Tech UniversityRustonLA 71272USA

Atomically thin Pt nanolayers were synthesized on the surface of Mo2tiC2 MXenes and used for the catalytic dehydrogenation of ethane and propane into ethylene and propylene,two important chemicals for the petrochemical *** compared with Pt nanoparticles,the atomically thin Pt nanolayer catalyst showed superior coke-resistance(no deactivation for 24 h),high activity(turnover frequencies(tOFs)of 0.4–1.2 s^(-1)),and selectivity(>95%)toward ethylene and *** unique Pt nanolayer has a similar geometric surface to Pt nanoparticles,enabling the investigations of the electronic effect on the catalytic performance,where the geometric effect is *** is found that the electronic effect plays a critical role in dehydrogenative product selectivity and catalyst *** metal–support interaction is found dependent on the substrate and metal components,providing wide opportunities to explore high-performance MXene-supported metallic catalysts.

关键词： MXene catalysis alkane dehydrogenation nanolayers

Electron localization of H_2^+ in a dc electric field

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Chinese Physics B 2017年第1期26卷 170-175页

作者： z M Jia z N zeng W t tang R X Li State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China Signal and Information Processing Jingchu University of Technology Jingmen 448000 China

A dc electric field is utilized to steer the electron motion after the molecular ion H2-＋ is excited by an ultrashort ultraviolet laser pulse. the numerical simulation shows that the electron localization distribution and the dissociation control ratio are dependent on the polarization direction and amplitude of the dc electric field. Most electrons of the dissociation state move opposite to the dc electric field and stabilize at the dressed-up potential well, for the dressed-down well is occupied by the electrons of the 1 sσg state.

关键词： dissociation localization time dependent Schrdinger equation Coulomb potential ultraviolet laser pulse

Steady vortex force theory and slender-wing flow diagnosis

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Acta Mechanica Sinica 2007年第6期23卷 609-619页

作者： Y.t.Yang R.K.zhang Y.R.An J.z.Wu State Key Laboratory for turbulence and Complex Systems College of EngineeringPeking UniversityBeijing 100871China

the concept vortex force in aerodynamics is sys- tematically examined based on a new steady vortex-force theory （Wu et al., Vorticity and vortex dynamics, Springer, 2006） which expresses the aerodynamic force （and moment） by the volume and boundary integrals of the Lamb vector. In this paper, the underlying physics of this theory is explored, including the general role of the Lamb vector in non- linear aerodynamics, its initial formation, and its relevance to the total-pressure non-uniformity. As a typical example, the theory is applied to the flow over a slender delta wing at a large angle of attack. the highly localized flow structures with high Lamb-vector peaks are identified in terms of their net contribution to various constituents of the total aerody-namic force. this vortex-force diagnosis sheds new light on the flow control and configuration optimization.

关键词： Vortex force - Delta-wing - Flow control

An Investigation of Ionic Flows in a Sphere-Plate Electrode Gap

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Plasma Science and technology 2013年第10期15卷 1012-1019页

作者： H.z.ALISOY S.ALAGOz G.t.ALISOY B.B.ALAGOz Department of Electrical-Electronics Inonu University Department of Physics Inonu University Department of Mathematics Inonu University

this paper presents analyses of ion flow characteristics and ion discharge pulses in a sphere-ground plate electrode system. As a result of variation in electric field intensity in the electrode gap, the ion flows towards electrodes generate non-uniform discharging pulses. Inspection of these pulses provides useful information on ionic stream kinetics, the effective thickness of ion cover around electrodes, and the timing of ion clouds discharge pulse sequences. A finite difference time domain （FDtD） based space-charge motion simulation is used for the numerical analysis of the spatio-temporal development of ionic flows following the first townsend avalanche, and the simulation results demonstrate expansion of the positive ion flow and compression of the negative ion flow, which results in non-uniform discharge pulse characteristics.

关键词： ion flow FDtD simulation space charge motion