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Discovery of the Baijifeng impact structure in Tonghua,Jilin,China

Matter and Radiation at Extremes 2023年第5期8卷 99-102页

作者： Ming Chen Yang Lu Jiahao Ning Wenge Yang Jinfu Shu Ho-kwang Mao Center for High Pressure Science and Technology Advanced Research Shanghai 201203People’s Republic of China

An impact structure 1400 m in diameter,formed by a bolide impact,has been discovered on Baijifeng Mountain in Tonghua City in Northeast China’s Jilin *** impact structure takes the form of a cirque-shaped depression on the top of the mountain and is located in a basement mainly composed of Proterozoic sandstone and Jurassic granite.A large number of rock fragments composed mainly of sandstone,with a small amount of granite,are distributed on the top of Baijifeng *** deformation features(PDFs)have been found in quartz in the rock and mineral clasts collected from the surface inside the *** forms of the PDFs indexed in the quartz include among others,{1013},{1012},and{1011}.The presence of these PDFs provides diagnostic evidence for shock metamorphism and the impact origin of the *** impact event took place after the Jurassic Period and probably much later.

关键词： sandstone quartz Jurassic

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Effect of Al addition and heat treatment on the microstructures and corrosion resistance of Mg-Cu alloys

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Journal of Materials science & technology 2022年第3期98卷 219-232页

作者： X.W.Wang W.Wang W.Chen D.M.Chen Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China College of Material Science and Engineering University of Science and Technology of ChinaShenyang 110016China

The effects of Al content and annealing condition on the microstructures and corrosion performances of Mg-3 wt.%Cu-xAl(x=0,4 wt.%,8 wt.%)alloys were *** Mg-3 wt.%Cu alloy contains Mg_(2)Cu phase,but Al-bearing alloys contain MgAlCu and Mg_(17)Al_(12) *** Mg_(2)Cu and MgAlCu phases exhibit much higher Volta potential compared to Mg_(17)Al_(12) and α-Mg,and their volume fractions are related to Al content of alloys and annealing *** weight loss measurement and electrochemical tests are conducted to explore the corrosion performances of *** close relationship between weight loss rate of alloys and volume fraction of Cu-bearing phases indicates that the corrosion performances of alloys can be controlled by adjusting Al content of alloys and annealing conditions.

关键词： Magnesium Intermetallics Weight loss EIS(electrochemical impedance spectroscopy)

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Wear behavior of the raw and pre-smashed carbon nanotubes reinforced 6061Al composites fabricated by powder metallurgy

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science China(Technological sciences) 2022年第5期65卷 1149-1159页

作者： LI XiaoNan LIU ZhenYu ZAN YuNing XIAO BoLü NI DingRui WANG QuanZhao WANG Dong MA ZongYi Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China

The raw and pre-smashed(PS)carbon nanotube(CNT)reinforced 6061Al composites(CNT/6061Al)with different CNT contents were respectively fabricated by powder metallurgy *** was found that reducing the CNT cluster size by presmashing processing could sharply reduce the friction coefficient,and significantly improve the density,hardness,and wear resistance of the CNT/6061Al *** the raw-CNT/6061Al composites,the wear rate increased approximately linear trend while the CNT content was over 1 wt.%.The plastic deformation,deep grooves,and serious delamination were presented on the wear *** wear process was gradually transformed from Al-copper base counterpart wear into Al-Al wear for the higher adhesion-binding energy between aluminum and copper base *** for the PS-CNT/6061Al composites,the wear rate gradually decreased as the CNT content increased from 0 to 2 wt.%.This was mainly because the generation of the thinner mechanically mixed layer(MML)and the PS-CNT prevented the direct contact between specimen and copper base counterpart,which effectively inhibited the adhesive *** excessive PS-CNTaddition(~3 wt.%)would weaken the bonding between CNT and 6061Al,and thus the wear resistance of the composite was reduced apparently.

关键词： wear carbon nanotube aluminum matrix composites clustering

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Effect of solution cooling rate on the microstructure and creep deformation mechanism of a rhenium-free second-generation single crystal superalloy

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Journal of Materials science & technology 2022年第36期131卷 14-29页

作者： Xipeng Tao Yunling Du Xinguang Wang Jie Meng Yizhou Zhou Jinguo Li Xiaofeng Sun Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Various cooling scenarios(water,oil,air and furnace)were employed to study the impacts of the solution cooling rate(SCR)on the microstructure and creep behavior of a novel single-crystal(SX)*** results showed that the cubic degree and size of theγphases were inversely proportional to the *** creep life first increased and then dropped dramatically with a reduction in the *** creep life of the sample cooled with air cooling(AC)was the highest,up to 144.90 h at 800℃/750 MPa and160.15 h at 1100℃/137 *** creep at 800℃/750 MPa,the improved creep life of the AC sample was mainly attributed to the fine cubicγphases,which decreased the rate ofγ-phase coarsening and favoured plastic deformation by promoting the active movement of *** AC helped theγphases become rich in Al,Ti and Ta while depleted in Co and Cr,which enhanced its stacking fault energy,thus promoting the formation of dislocation ***,the largest negative lattice misfit caused by AC induced denserγ/γinterface dislocation networks at 1100℃/137 MPa,which efficiently reduced the minimum creep *** calculated average dislocation spacing results indicated that the smallest density of excess dislocations corresponded to the AC sample,proving its greatest creep ***,the size of the secondaryγphases first decreased and then increased sharply with decreasing SCR during creep at 1100℃/137 MPa,when fine secondaryγphases had a positive role in the blockage of dislocation movement in the ***,the comprehensive SCR effect was explored to provide more guidance in the design of Re-free SX superalloys.

关键词： Solution cooling rate Microstructure Creep property Deformation mechanism Single crystal superalloy

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Wettability and Interfacial Reactions Between Metallic Glass Melts and Cu/Mo Used as Roller Materials for Twin-Roll Casting

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Acta Metallurgica Sinica(English Letters) 2022年第7期35卷 1221-1230页

作者： Yi Wu Long Zhang Hongwei Zhang Huameng Fu Zhengwang Zhu Hong Li Aimin Wang Haifeng Zhang Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China

Twin-roll casting has been recently revealed to be an effi cient technique to produce rejuvenated metallic glass(MG)*** to the high melting point and high hardness,pure Mo is considered as a good roller material as pure ***,the wettability and interfacial reactions between MG melts and Cu or Mo remain largely *** this work,a series of sessile droplet wetting experiments are designed to investigate the wettability and reactions between Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5)(Vit.1)or(Zr 0.401 Ti_(0.133)Cu_(0.118)Ni_(0.101)Be_(0.247))_(99)Nb_(1)(Nb1)MG melts and Cu/Mo substrates at temperatures of 1073,1123 and 1173 *** is found that the wettability and interfacial reactions of the Vit.1 and Nb1 MG melts on the Cu substrates are very *** equilibrium contact angles are~30°at 1073 K and~25°-27°at 1123 *** MG melts completely spread out on the Cu substrates at 1173 *** substrates are slightly dissolved in the MG melts event at 1073 K,and a transitional reaction layer exists between the droplet and the Cu *** comparison,the Vit.1 MG melt exhibits a much improved wettability on the Mo *** equilibrium contact angle of the Vit.1/Mo is only 6°at 1073 K and 5°at 1123 *** signifi cant diff usion of Mo into the droplet occurs even at 1173 K with a holding time of~30 *** interfaces of the Vit.1/Mo samples are sharp,and no interfacial reaction layers *** fi ndings indicate that pure Mo can be a good roller material for twin-roll casting at high temperatures,and the Mo-made rollers are expected of capability to produce MG strips with good quality.

关键词： Metallic glass Wettability Interfacial reaction Twin-roll casting Roller material

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Smart contact lenses:Catalysts for science fiction becoming reality

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The Innovation 2024年第6期5卷 23-24页

作者： Guang Yao Peisi Li Mingpeng Liu Feiyi Liao Yuan Lin School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 610054China State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610054China Institute of Materials China Academy of Engineering PhysicsJiangyou 621908China Medico-Engineering Cooperation on Applied Medicine Research Center University of Electronic Science and Technology of ChinaChengdu 610054China Shenzhen Institute for Advanced Study University of Electronic Science and Technology of ChinaShenzhen 518110China

Smart glasses are multifunctional devices designed to replicate the capabilities of smartphones,offering entertainment,fitness tracking,and various other ***,currently available head-mounted devices tend to be large and heavy,leading to discomfort and diminished *** contrast,the advent of smart contact lenses(SCLs)signifies a significant advancement beyond mere entertainment,representing a groundbreaking intersection of traditional eyewear and advanced scientific innovation.

关键词： mounted breaking Smart

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A review of control strategies used for morphing aircraft applications

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Chinese Journal of Aeronautics 2024年第4期37卷 436-463页

作者： Muhammed S.PARANCHEERIVILAKKATHIL Jafar S.PILAKKADAN Rafic M.AJAJ Mohammadreza AMOOZGAR Davood ASADI Yahya ZWEIRI Michael I.FRISWELL Department of Aerospace Engineering Khalifa University of Science and TechnologyAbu DhabiUnited Arab Emirates Department of Aerospace Engineering Advanced Research and Innovation Center(ARIC)Khalifa University of Science and TechnologyAbu DhabiUnited Arab Emirates Department of Mechanical Materials&Manufacturing EngineeringUniversity of NottinghamNottingham NG72RDUK Department of Aerospace Engineering Adana Alparslan Turkes Science and Technology UniversityTurkey College of Engineering Swansea UniversitySwansea SA18ENUK

This paper reviews the various control algorithms and strategies used for fixed-wing morphing aircraft applications. It is evident from the literature that the development of control algorithms for morphing aircraft technologies focused on three main areas. The first area is related to precise control of the shape of morphing concepts for various flight conditions. The second area is mainly related to the flight dynamics, stability, and control aspects of morphing aircraft. The third area deals mainly with aeroelastic control using morphing concepts either for load alleviation purposes and/or to control the instability boundaries. The design of controllers for morphing aircraft/wings is very challenging due to the large changes that can occur in the structural, aerodynamic, and inertial characteristics. In addition, the type of actuation system and actuation rate/speed can have a significant effect on the design of such controllers. The aerospace community is in strong need of such a critical review especially as morphing aircraft technologies move from fundamental research at a low technology Readiness Level(TRL) to real-life applications. This critical review aims to identify research gaps and propose future directions. In this paper, research activities/papers are categorized according to the control strategy used. This ranges from simple Proportional Integral Derivative(PID) controllers at one end to complex robust adaptive controllers and deep learning algorithms at the other end. This includes analytical, computational, and experimental studies. In addition, the various dynamic models used and their fidelities are highlighted and discussed.

关键词： Control strategies Morphing aircraft Shape morphing Flight dynamics Aeroelasticity

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Statistical study of magnetic holes in the upstream region of Mercury’s bow shock

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Earth and Planetary Physics 2024年第2期8卷 326-337页

作者： GuoQiang Wang SuDong Xiao MingYu Wu YuanQiang Chen TieLong Zhang Institute of Space Science and Applied Technology Harbin Institute of TechnologyShenzhen 518055China Shenzhen Key Laboratory of Numerical Prediction for Space Storm Harbin Institute of TechnologyShenzhen 518055China Mengcheng National Geophysical Observatory University of Science and Technology of ChinaHefei 230026China Chinese Academy of Sciences Center for Excellence in Comparative Planetology Hefei 230026China Space Research Institute Austrian Academy of SciencesGrazAustria

Magnetic holes are magnetic depression structures that exist widely in many plasma *** magnetic holes with durations of>1 s in the solar wind at Mercury’s orbit have drawn much attention,but the properties of the magnetic holes with shorter durations are still ***,we investigate the magnetic holes with durations of 0.1-100 s in the upstream region of Mercury’s bow shock based on observations by the MESSENGER(MErcury Surface,Space ENvironment,GEochemistry,and Ranging)*** can be divided into two groups according to the distribution of their duration:small-duration magnetic holes(SDMHs,<0.6 s)and large-duration magnetic holes(LDMHs,>0.6 s).The duration of each group approximately obeys a log-normal distribution with a median of~0.25 s and 3 s,*** 1.7%(32.6%)of the SDMHs(LDMHs)reduce the magnetic field strength by more than 50%.For both groups,some structures have a linear or quasi-linear polarization,whereas others have an elliptical *** magnetic hole events in both groups tend to have a higher rate of occurrence when the interplanetary magnetic field strength is *** occurrence rates are also affected by Mercury’s foreshock,which can increase(decrease)the occurrence rate of the SDMHs(LDMHs).This finding suggests that Mercury’s foreshock might be one source of the SDMHs and that the foreshock can destroy some *** observations suggest that a new group of magnetic holes with durations of<0.6 s exist in the upstream region of Mercury’s bow shock.

关键词： magnetic hole solar wind Mercury foreshock

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Wear Behavior of the Uniformly Dispersed Carbon Nanotube Reinforced 6061Al Composite Fabricated by Milling Combined with Powder Metallurgy

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Acta Metallurgica Sinica(English Letters) 2022年第11期35卷 1765-1776页

作者： Xiaonan Li Zhenyu Liu Zhixin Dai Hui Feng Bolyu Xiao Dingrui Ni Quanzhao Wang Dong Wang Zongyi Ma School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The uniformly dispersed carbon nanotubes(CNTs) reinforced 6061Al composites(CNT/6061Al) with diff erent CNT concentrations were fabricated by powder metallurgy technology. It was found that the friction coe ffi cient as well as wear rate decreased fi rst and then increased as the CNT concentration increasing under 15 N as well as 30 N, and the minimum wear rate was achieved at the CNT concentration of 2 wt%. Adhesive wear and abrasive wear were the dominated wear mechanisms for the 1–2 wt% CNT/6061Al composites under 15 N and 30 N, while the delamination occurred on the wear surface at 3wt% CNT. As the applied load increased to 60 N, the wear rate of composites increased dramatically. The wear mechanism transformed from abrasive wear to severe delamination wear, accompanied by the generation of wear debris with sharp edge due to the weaker anti-shearing strain capacity of CNT/6061Al composites.

关键词： Wear mechanism Carbon nanotube Aluminum matrix composites Powder metallurgy

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Improved Spallation Resistance of the Oxide Scale by Hf/Y Co-doping in Ni-Based Superalloy at High Temperature

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Acta Metallurgica Sinica(English Letters) 2022年第10期35卷 1744-1758页

作者： Khalil Rehman Naicheng Sheng Shigang Fan Shijie Sun Guicheng Hou Yizhou Zhou Xiaofeng Sun Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Material Science and Engineering University of Science and Technology of ChinaHefei230026China

Ni-based superalloys added with comparably higher concentrations of single-doped Hf and co-doped Hf/Y are prepared by vacuum induction melting(VIM).The oxidation properties up to 300 h at 900℃,1000℃,and 1100℃ are *** undoped alloy exhibited a minimum oxidation rate at 900℃ and 1000℃.The co-doped alloy showed a higher oxidation rate;however,it possesses better scale adhesion,and no spallation ***-doped alloy showed a lower oxidation rate and better scale adhesion at 900℃ and 1000℃,but exhibited a shorter lifetime at 1100℃.The spallation of the Hf-doped alloy is attributed to the precipitation of the HfO2 in and beneath the oxide *** spallation in the undoped alloy is accredited to the thermal expansion mismatch between the growing oxide scale and superalloy *** two reactive elements(REs)in alloy minimized the precipitation of RE oxide in the oxide scale,diminished internal oxidation in the alloy,and decreased oxide scale spallation.

关键词： Superalloys Reactive elements Oxidation kinetics Microstructure Spallation resistance

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