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Microstructure and Mechanical Properties of 7005 Aluminum Alloy Components Formed by Thixoforming

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Journal of Materials Science & Technology 2017年第4期33卷 379-388页

作者： Jufu Jiang h.V.Atkinson Ying wang School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China Department of Engineering University of Leicester University Road Leices-ter LE1 7RH UK School of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 China

In the present research, semisolid billet of 7005 aluminum alloy was fabricated by using recrystallization and partial remelting（RAP）, then thixoformed at different isothermal temperatures, preheating temperatures and load routes. Mechanical properties and microstructure of the thixoformed product were investigated. The results showed that microstructure achieved by three-step induction heating warm extruded 7005 aluminum alloy consists of a uniform and spheroidal microstructure suitable for thixoforming.Preheating temperature of the die affected significantly the filling status of semisolid billet of 7005 aluminum alloy. Complete filling status with good surface quality was obtained at a preheating temperature of 365 ℃. Thixoformed microstructures consisting of relatively spheroidal grains illustrate the dependence of filling process on the sliding and rotating of solid grains rather than plastic deformation of solid grains. A non-uniform distribution of liquid phase was found in the different regions of the thixoformed product due to the slower adjustable velocity of solid grains as compared with liquid phase. Increase of isothermal temperatures led to a slight decrease of mechanical properties of the thixoformed product due to coarsening of solid grains. The highest yield strength, ultimate tensile strength and elongation of thixoformed components with T6 heat treatment are 237 MPa, 361 MPa and 16.8%, respectively, which were achieved at the isothermal temperature of 605℃. Load route has a significant effect on mechanical properties and microstructure of the thixoformed product. Defects, such as crack and microporosity occurred in the microstructure of the thixoformed product obtained under load route 2. It led to an obvious reduction of mechanical properties as compared with route 1. A better compatibility of deformation caused by more liquid fraction at the isothermal temperature of 612℃ is beneficial to reducing nonuniformity of liquid phase in the different regions of the thixoformed product.

关键词： 7005 aluminum alloy Microstructure Mechanical properties Semisolid billet Thixoforming

A review of the characteristics and precise diagnosis value of electrocochleography in patients with auditory neuropathy

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Zhonghua er bi yan hou tou jing wai ke za zhi = Chinese journal of otorhinolaryngology head and neck surgery 2024年第5期59卷 495-500页

作者： Wu K.L. Wang H.Y. wang Q.J. Department of Audio-Vestibular Medicine Senior Department of Otolaryngology-Head and Neck Surgery the Sixth Medical Center of Chinese PLA General Hospital Beijing 100048 China

听神经病是一种听觉处理障碍性疾病。不同病变部位对于听觉功能的影响存在异质性，导致了患者表型、预后存在差异。对于部分病因明确的患者，可推测其病变部位，但对于病因未明的患者，电生理检查，尤其是耳蜗电图似乎成为判断病变部位... 详细信息

听神经病是一种听觉处理障碍性疾病。不同病变部位对于听觉功能的影响存在异质性，导致了患者表型、预后存在差异。对于部分病因明确的患者，可推测其病变部位，但对于病因未明的患者，电生理检查，尤其是耳蜗电图似乎成为判断病变部位的重要手段。本文就国内外报道的听神经病患者耳蜗电图特征予以综述，并探讨其在定位分型、精细诊断中的作用。

关键词：耳蜗电图电生理检查听神经病听觉功能未明障碍性疾病病变部位异质性

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 method.The 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 metals.This enhancement is ascribed to a win-win mechanism of nanoscale heterojunctions and sulfur vacancies.The 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 separation.Meanwhile,the sulfur vacancies existing in ZnIn_(2)S_(4) can capture photoelectrons and act as active sites,facilitating the h_(2) generation reaction.In 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 performance.This research provides new insights into the regulation of charge transfer through embedding nanocrystals.

关键词： Photocatalysis hydrogen evolution Laser irradiation heterostructure Sulfur vacancies

Predictive fatigue crack growth law of high-strength steels

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Journal of Materials Science & Technology 2022年第5期100卷 46-50页

作者： h.F.Li P.Zhang B.wang Z.F.Zhang Laboratory of Fatigue and Fracture for Materials Shi-changxu Innovation Center for Advanced MaterialsChinese Academy of SciencesInstitute of Metal ResearchShenyang 110016China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

The fatigue resistance of metallic materials is generally attributed to both strength and toughness.Unfortunately,these properties are mutually exclusive in most materials.Classical theories like Paris’law only provide some data correlation schemes rather than a predictive capability,which cannot satisfactorily guide the anti-fatigue design.In this study,for the first time,the predictive fatigue crack growth rate law is proposed by considering the effects of both strength and toughness.Accordingly,a quantitative criterion is established for judging the fatigue crack resistance of high-strength steels.The predictive law would provide a unique view to the quantitative anti-fatigue design of metallic materials.

关键词： Fatigue crack growth Strength and toughness Paris’law high-strength steels

Introduction to the Special Issue on Computer Modelling of Transmission, Spread, Control and Diagnosis of COVID-19

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Computer Modeling in Engineering & Sciences 2021年第5期127卷 385-387页

作者： Yudong Zhang Qilong wang Sean h.Y.Yuan School of Informatics University of LeicesterLeicesterLE17RHUK The Affiliated huai’an No.1 People’s hospital Nanjing Medical UniversityHuai’an223300China Department of Biomedical Sciences City University of Hong KongHong KongChina

The 2019–20 coronavirus pandemic is an ongoing pandemic of coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).It was declared to be a Public health Emergency of International Concern and recognized as a pandemic by the World health Organization.The outbreak of COVID-19 has rapidly spread to most countries in the world.This special issue started at 21 April 2020,when there were more than 2.5 million confirmed cases and 174,336 deaths around the world.After 10 months,this special issue closes at 23 February 2021,the two figures increase to 112.2 million confirmed cases and 2.48 million death tolls,respectively.

关键词： acute respiratory death

Microstructure change in Fe-based metallic glass and nanocrystalline alloy induced by liquid nitrogen treatment

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Journal of Materials Science & Technology 2021年第10期69卷 1-6页

作者： M.C.Ri D.W.Ding Y.h.Sun W.h.wang Institute of Physics Chinese Academy of SciencesBeijing100190China Songshan Lake Materials Laboratory Dongguan523808China

The effects of acyclic liquid nitrogen(LN)treatment in a temperature range of-196℃to 50℃on the thermal and magnetic stability of Fe78Si9B13 and Fe73.5Si13.5B9Nb3Cu1 glassy ribbons have been studied.The intrinsic heterogeneities of the metallic glasses can be activated through cryogenic thermal cycling,making irreversible structural changes after the treatment and inducing rejuvenation to the materials.The microstructural changes of both Fe-based metallic glass(MG)and nanocrystalline alloy induced by LN treatment were investigated.The experimental results show that the LN treatment could effectively rejuvenate the Fe-Si-B MGs and change their thermomechanical and magnetic properties.Based on the partially-crystallinity and well-known magnetic constants,the increase of the energy at the order of 10m J/g and magnetic domain wall movement and rotation at the order of 5-6μm and 0.5°-0.8°are found for FINEMET-type amorphous alloy after LN treatment.It is also found that LN treatment can contribute a little stored energy to the magnetic domain wall movement and magnetic domain rotation.

关键词： Metallic glasses Cryogenic thermal treatment Soft magnetic materials Rejuvenation Stored energy Domain wall

全局检验与事后检验之间的联系:ANOVA方差分析中F检验结果的一项调查（英文）

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上海精神医学 2018年第1期30卷 60-64页

作者： Chen T Xu M Tu J Wang H Niu X Department of Mathematics and Statistics University of Toledo Shanghai Mental health Center Shanghai Jiao Tong University Medical College Department of Physical Medicine and Rehabilitation University of Virginia School of Medicine Department of Biostatistics and Computational Biology University of Rochester College of Informatics Huazhong Agriculture University

多组比较在许多生物医学和心理社会学研究中是一种常见的统计检验。当组数为两个以上时,首先对组间的整体差异进行全局检验。如果零假设被拒绝,则接着进行下一步的事后两两组间比较,以确定差异的来源。相反,第一步停止即可声明没有组间... 详细信息

多组比较在许多生物医学和心理社会学研究中是一种常见的统计检验。当组数为两个以上时,首先对组间的整体差异进行全局检验。如果零假设被拒绝,则接着进行下一步的事后两两组间比较,以确定差异的来源。相反,第一步停止即可声明没有组间差异。一个共同认识是如果全局检测结果是显著的,那么至少存在两个组之间是有显著差异的,反之亦然。因此,当全局检测结果显著,但没有事后组间两两比较没有显著差异,人们会感到困惑发生了什么并想知道如何来解释该结果。总之,当全局检测结果不显著时,人们会想知道是否所有的事后检测也都不显著?同样,全局检测结果不显著而停止事后检测是否会导致发现组差差异的丢失?在这篇报告中,我们研究了这个令人费解的现象,并且讨论了如何解释这样的结果。

关键词：全局检测事后检验 F检验图基(Tukey)检验

城市更新中可持续场地规划的决策影响因素框架

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城市规划学刊 2016年第3期 123-124页

作者： Wang H ShEN Q TANG B 柳兰萱

城市更新是城市发展领域日益显著的热点话题。场地规划作为城市更新的前提保障,对复兴老城区、取得成功的未来发展有着直接的作用。但涉及规划重建及土地使用的决策过程十分复杂,也没有得到规划实践者足够的重视,因而,需要一些新的工具... 详细信息

城市更新是城市发展领域日益显著的热点话题。场地规划作为城市更新的前提保障,对复兴老城区、取得成功的未来发展有着直接的作用。但涉及规划重建及土地使用的决策过程十分复杂,也没有得到规划实践者足够的重视,因而,需要一些新的工具和方法来帮助做出决策。另一方面,可持续的发展已成为规划领域的共识,许多学者已经在这方面进行过探讨。这篇论文在回顾文献的基础上,

关键词：城市更新老城区场地规划决策影响

Synergistic protection of Si anode based on multi-dimensional graphitic carbon skeletons

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Nano Research 2022年第9期15卷 8146-8155页

作者： Qitao Shi haiming wang Junhua Zhou huyQuang Ta Jiaqi wang Xueyu Lian Klaudia Kurtyka Barbara Trzebicka Thomas Gemming Mark h.Rümmeli Soochow Institute for Energy and Materials Innovation College of EnergyKey Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou 215006China Institute for Complex Materials IFW Dresden20 Helmholtz StrasseDresden 01069Germany Centre of Polymer and Carbon Materials Polish Academy of SciencesM.Curie-Sklodowskiej 34Zabrze 41-819Poland Thomas Gemming-Institute of Environmental Technology VSB-Technical University of Ostrava17.Listopadu 15Ostrava 70833Czech Republic

Inspired by the natural corn structure,a Si@hollow graphene shell@graphene(Si@GS@G)anode material was prepared in which silicon nanoparticles were preliminarily anchored onto the surface of an elastic graphene shell and further constrained using graphene sheets.hollow graphene oxide shells with abundant surficial hydrogen bonds,which were synthesized using a novel bottom-up method,were used as an intermediate material to anchor positively charged silicon nanoparticles via electrostatic attraction and achieve a rational spatial distribution.The inner hollow graphene shell anchorage and outer graphene constraint synergistically constituted a porous and robust conductive corn-like structure.The as-fabricated Si@GS@G anode afforded efficient electron and ion transport pathways and improved structural stability,thereby enhancing Li+storage capability(505 mAh·g^(−1)at 10 A·g^(−1))and extending the lifespan compared to the single hollow graphene shell or graphene sheet-protected Si anode(72%capacity retention after 500 cycles).The improved kinetics of the Si@GS@G anode were investigated using electro impedance spectroscopy,galvanostatic intermittent titration,and pseudocapacitance contribution rate analysis,and the structural evolution was analyzed using ex situ electron microscopy.This study proposes a novel hollow graphene oxide shell as an activated intermediate material for designing a porous electrode structure that facilitates an enhanced electrochemical performance.

关键词： synergistic protection multi-dimensional graphitic carbons corn-like structure elastic skeleton Si/C anode