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Microstructural evolution and superelastic properties of ultrafine-graine d NiTi-base d shape memory alloy via sintering of amorphous ribbon precursor

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Journal of Materials Science & Technology 2023年第7期138卷 80-92页

作者： w.S.Cai h.z.Lu h.z.Li z.Liu h.B.Ke w.h.w.ng C.yang National Engineering Research Center of Near-net-shape Forming for Metallic Materials Guangdong Provincial Key Laboratory for Processing and Forming of Advanced Metallic MaterialsSouth China University of TechnologyGuangzhou 510640China Songshan Lake Materials Laboratory Dongguan 523808China Institute of physics Chinese Academy of SciencesBeijing 100190China

NiTi-based shape memory alloys(SMAs)are considered as cutting-edge intelligent functional ***,it remains a great challenge to obtain ultrafine-grained(UFGed)bulk materials with mm-scale size as well as outstanding superelastic ***,UFGed bulk Ti_(35)zr_(15)Ni_(35)Cu_(15)NiTi-based SMA is successfully prepared via spark plasma sintering of amorphous ribbon precursor at different sintering temperatures,and microstructural evolution and superelastic properties are symmetrically *** is found that its grain size ranges from UFG to micro-grain with increased sintering temperature regard-less of the predominant B2 matrix in all bulk ***,the orientation relationships between B2 matrix and nano-scale fcc(Ti,zr)_(2)Ni precipitate evolve from coherent to ***,the UFGed samples exhibit perfect superelasticity with the high recoverable strain of∼5.8%,the stable recov-ery rate above 99%,and the great critical stress inducing martensitic transformation higher than 1 Gpa,far superior to the corresponding ones of suction-cast micro-grained TizrNiCu ***,the perfect superelasticity is attributed to the good resistance to dislocation slip or grain boundary slip by residual nano-scale amorphous phase or secondary phase of coherent and semi-coherent fcc(Ti,zr)_(2)Ni *** addition,the gentle superelastic plateau is associated to the favorable transfer stress and the strong ability to accommodate dislocation movement,which is generated by the coherent interface between nano-scale fcc(Ti,zr)_(2)Ni and UFGed B2 *** results suggest that spark plasma sintering of amorphous alloy precursor is a feasible route to obtaining excellent superelasticity in NiTi-based SMAs.

关键词： Shape memory alloy Amorphous alloy Microstructure Superelasticity

high-temperature fatigue strength of grain boundaries with different misorientations in nickel-based superalloy bicrystals

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Journal of Materials Science & Technology 2023年第23期154卷 94-106页

作者： d.F.Shi z.J.zhang Y.h.yang Y.z.zhou R.Liu p.zhang z.F.zhang Shi-changxu Innovation Center for Advanced Materials Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China School of Materials Science and Engineering University of Science and Technology of China Shenyang 110016 China

Nickel-based single-crystal superalloys are widely used in the manufacture of aeroengine turbine vanes for their excellent high-temperature performance. Low-angle grain boundaries (LAGBs) will be generated inevitably during their manufacture, which are often characterized by grain boundary misorientation (GBM) and will weaken the mechanical properties of superalloys. h.w.ver, the relationship between GBM and the fatigue properties of superalloys at elevated temperatures has seldom been investigated due to the difficulty in the sample preparation and experiment process. Based on six kinds of bicrystals with different tilt LAGBs made by a second-generation single-crystal superalloy, the effects of misorientation on the grain boundary microstructure and fatigue properties (980 °C) of superalloys were studied systematically in this work. It is found that, with the increase of GBM, the GB precipitates combined with the cast micropores increase monotonically, accordingly both the fatigue life and fatigue strength decrease successively. Fatigue fracture observations sh.w.that the cracks of all the bicrystals initiated from the cast micropores at GBs, and then propagated along the GBs. Therefore, the coupling effect of cast micropores and GBM on the fatigue damage mechanisms of the bicrystals are evaluated according to their hindering degrees on the piled-up dislocations. Combining with a hysteresis energy model, a quantitative fatigue strength prediction model of superalloys is established and is well verified by abundant experimental data. This study could.p.ovide guidance for fatigue performance prediction and structural design of superalloys.

关键词： Superalloys Bicrystals Grain boundary misorientation Fatigue strength Fatigue crack

A mosquito mouthpart-like bionic neural probe

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Microsystems & Nanoengineering 2023年第4期9卷 77-90页

作者： Yu zhou huiran yang Xueying wang heng yang Ke Sun zhitao zhou Liuyang Sun Jianlong zhao Tiger h.tao Xiaoling wei State Key Laboratory of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences200050 ShanghaiChina School of Graduate Study University of Chinese Academy of Sciences100049 BeijingChina 2020 X-Lab Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences200050 ShanghaiChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences100049 BeijingChina Center for Excellence in Brain Science and Intelligence Technology Chinese Academy of Sciences200031 ShanghaiChina Neuroxess Co. Ltd.(Jiangxi)330029 NanchangJiangxiChina Guangdong Institute of Intelligence Science and Technology Hengqin519031 ZhuhaiGuangdongChina Tianqiao and Chrissy Chen Institute for Translational Research ShanghaiChina

Advancements in microscale electrode technology have revolutionized the field of neuroscience and clinicalapplications by offering high temporal and spatial resolution of recording and stimulation. Flexible neural probes, withtheir mechanical compliance to brain tissue, have been sh.w. to be superior to rigid devices in terms of stability andlongevity in chronic recordings. Shuttle devices are commonly used to assist flexible probe implantation;h.w.ver, theprotective membrane of the brain still makes penetration difficult. hidden damage to brain vessels duringimplantation is a significant risk. Inspired by the anatomy of the mosquito mouthparts, we present a biomimeticneuroprobe system that integrates high-sensitivity sensors with a high-fidelity multichannel flexible electrode *** customizable system achieves distributed and minimally invasive implantation across brain regions. Mostimportantly, the system’s nonvisual monitoring capability provides an early warning detection for intracranial softtissues, such as vessels, reducing the potential for injury during implantation. The neural probe system demonstratesexceptional sensitivity and ad.p.ability to environmental stimuli, as well as outstanding performance in postoperativeand chronic recordings. These findings suggest that our biomimetic neural-probe device offers promising potential forfuture applications in neuroscience and brain-machine interfaces.

关键词： neural implantation recording

A silk-based self-ad.p.ive flexible opto-electro neural probe

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Microsystems & Nanoengineering 2022年第6期8卷 85-96页

作者： Yu zhou Chi Gu Jizhi Liang Bohan zhang huiran yang zhitao zhou Meng Li Liuyang Sun Tiger h.tao Xiaoling wei State Key Laboratory of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences200050 ShanghaiChina School of Graduate Study University of Chinese Academy of Sciences100049 BeijingChina School of physical Science and Technology ShanghaiTech University200031 ShanghaiChina 2020 X-Lab Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences200050 ShanghaiChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences100049 BeijingChina Center for Excellence in Brain Science and Intelligence Technology Chinese Academy of Sciences200031 ShanghaiChina Neuroxess Co. Ltd.(Jiangxi)330029 NanchangJiangxiChina Guangdong Institute of Intelligence Science and Technology Hengqin519031 ZhuhaiGuangdongChina Tianqiao and Chrissy Chen Institute for Translational Research ShanghaiChina

The combination of optogenetics and electrophysiological recording enables high-precision bidirectional interactions between neural interfaces and neural circuits,which provides a promising approach for the study of progressive neurophysiological ***-electrophysiological neural probes with sufficient flexibility and biocompatibility are desirable to match the low mechanical stiffness of brain tissue for chronic reliable ***,lack of rigidity poses challenges for the accurate implantation of flexible neural probes with less ***,we report a hybrid.p.obe(Silk-Optrode)consisting of a silk protein optical fiber and multiple flexible microelectrode *** Silk-Optrode can be accurately inserted into the brain and.p.rform synchronized optogenetic stimulation and multichannel recording in freely behaving *** plays an important role due to its high transparency,excellent biocompatibility,and mechanical *** the hydration of the silk optical fiber,the Silk-Optrode probe enables itself to actively ad.p. to the environment after implantation and reduce its own mechanical stiffness to implant into the brain with high fidelity while maintaining mechanical compliance with the surrounding *** probes with 128 recording channels can detect high-yield well-isolated single units while performing intracranial light stimulation with low optical losses,surpassing previous work of a similar *** months of post-surgery results suggested that as-reported Silk-Optrode probes exhibit better implant-neural interfaces with less immunoreactive glial responses and tissue lesions.

关键词： neural recording implantation

Toward qualification of additively manufactured metal parts:Tensile and fatigue properties of selective laser melted Inconel 718 evaluated using miniature specimens

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Journal of Materials Science & Technology 2022年第2期97卷 239-253页

作者： h.Y.wan w.K.yang L.Y.wang z.J.zhou C.p.Li G.F.Chen L.M.Lei G.p.zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Materials&Manufacturing Qualification Group Corporate TechnologySiemens Ltd.Beijing 100102China AECC Shanghai Commercial Aircraft Engine Manufacturing Co. LtdShanghai 201306China

Combined with the topology optimization,additive manufacturing can be used to fabricate metal parts with complex ***,due to the geometrical variations and microstructure heterogeneities of the additively manufactured metal parts,new standards with the use of miniature specimens are required for the evalutation of the spatial distribution of mechanical properties throughout the ***,we conduct a systematic investigation on tensile and fatigue properties of selective laser melted Inconel718 specimens with different thicknesses ranging from 0.1 mm to 1 mm.A“microstructure unit”that can well reflect the microstructure characteristic of selective laser melted materials is *** results reveal that premature necking with a dramatic drop in uniform elongation occurs if the ratio(t/d)of specimen thickness(t)to the"microstructure unit"size(d)is less than *** necking is mainly attributed to the transition of strain localization *** also propose a probabilistic statistical model for fatigue limit prediction based on the available fatigue *** is recommended that the criterion of t/d≥4 should be satisfied to ensure that the yield strength,the uniform elongation,and the fatigue limit determined by the miniature specimens are comparable with those determined by standard *** findings may provdie a guide to the establishment of miniature specimen-based standards toward the qualification of additively manufactured metal parts.

关键词： Selective laser melting Inconel 718 Miniature specimen Microstructure unit Thickness effect

Three-dimensional structure of the wild-type RhdV

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Chinese Science Bulletin 2001年第12期46卷 1005-1009页

作者： zhENG dong XUE tao ChEN donghua zhENG Ming z.h.zhou XU wei Beijing Laboratory of Electron Microscopy Institute of PhysicsChinese Academy of SciencesBeijing 100080China d.p.rtment of pathology and Laboratory Medicine University of Texas-Houston Medical SchoolHoustonTX 77030USA Institute of Biophysics Chinese Academy of SciencesBeijing 100101China Analytical and Testing Center Beijing Normal UniversityBeijing 100875China China Institute of Veterinary drug Control Beijing 100081China

The three-dimensional (3d) structure of the wild-type rabbit hemorrhagic disease virus (RhdV) has been determined to a resolution of 3.2 nm by electron cryo-microscopy and computer image reconstruction techniques. The 3d density map exhibits characteristic structural features of a calicivirus: a T=3 icosahedral capsid with 90 arch-like capsomeres at the icosahedral and local 2-fold axes and 32 large surface hollows at the icosahedral 5- and 3-fold axes. This result confirms that the RhdV isolated in China is a member of the Caliciviridae family. A rather continuous capsid shell was found without channels. h.w.ver, our RhdV structure also reveals some distinct structural char-acteristics not observed in other caliciviruses, including interconnected capsomeres and the lack of protuberance on the base of each of the surface hollows. Two types of particles were identified with similar outer capsid structure but different density distributions inside the capsid shells, which could not be distinguished by

关键词： electron cryomicroscopy three-dimensional reconstruction RhdV calicivirus.

Einstein probe discovery of Ep240408a: A peculiar X-ray transient with an intermediate timescale

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Science China(physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 222-240页

作者： wenda zhang weimin Yuan zhixing Ling Yong Chen Nanda Rea Arne Rau zhiming Cai huaqing Cheng Francesco Coti zelati Lixin dai Jingwei hu Shumei Jia Chichuan Jin dongyue Li paul O’Brien Rongfeng Shen Xinwen Shu Shengli Sun Xiaojin Sun Xiaofeng wang Lei yang Bing zhang Chen zhang Shuang-Nan zhang Yonghe zhang Jie An david Buckley Alexis Coleiro Bertrand Cordier Liming dou Rob Eyles-Ferris zhou Fan hua Feng Shaoyu Fu Johan p.U.Fynbo Lluis Galbany Saurabh.w.Jha Shuaiqing Jiang Albert Kong Erik Kuulkers weihua Lei wenxiong Li Bifang Liu Mingjun Liu Xing Liu Yuan Liu zhu Liu Chandreyee Maitra Alessio Marino Itumeleng Monageng Kirpal Nandra Jeremy Sanders Roberto Soria Lian tao Junfeng wang Song wang Tinggui wang zhongxiang wang Qingwen wu Xuefeng wu dong Xu Yanjun Xu Suijian Xue Yongquan Xue zijian zhang zipei zhu hu zou Congying Bao Fansheng Chen houlei Chen Tianxiang Chen wei Chen Yehai Chen Yifan Chen Chenzhou Cui weiwei Cui Yanfeng dai dongwei Fan Ju Guan dawei han dongjie hou haibo hu Maohai huang Jia huo zhenqing Jia Bowen Jiang Ge Jin Chengkui Li Junfei Li Longhui Li Maoshun Li wei Li zhengda Li Tianying Lian Congzhan Liu heyang Liu huaqiu Liu Fangjun Lu Laidan Luo Jia Ma Xuan Mao haiwu pan Xin pan Liming Song hui Sun Yunyin Tan Qingjun Tang Yihan tao hao wang Juan wang Lei wang wenxin wang Yilong wang Yusa wang Qinyu wu haitao Xu Jingjing Xu Xinpeng Xu Yunfei Xu zhao Xu Changbin Xue Yulong Xue Ailiang Yan haonan yang Xiongtao yang Yanji yang Juan zhang Mo zhang wenjie zhang zhen zhang zhen zhang ziliang zhang donghua zhao haisheng zhao Xiaofan zhao zijian zhao hongyan zhou Yilin zhou Yuxuan zhu zhencai zhu National Astronomical Observatories Chinese Academy of Sciences School of Astronomy and Space Sciences University of Chinese Academy of Sciences Key Laboratory of particle Astrophysics Institute of high Energy physics Chinese Academy of Sciences Institute of Space Sciences (ICE) CSIC Institut d’Estudis Espacials de Catalunya (IEEC) Max planck Institute for Extraterrestrial physics Innovation Academy for Microsatellites Chinese Academy of Sciences d.p.rtment of physics University of hong Kong School of physics and Astronomy University of Leicester School of physics and Astronomy Sun Yat-sen University d.p.rtment of physics Anhui Normal University Shanghai Institute of Technical physics Chinese Academy of Sciences physics d.p.rtment Tsinghua University Nevada Center for Astrophysics University of Nevada Las Vegas d.p.rtment of physics and Astronomy University of Nevada Las Vegas South African Astronomical Observatory d.p.rtment of Astronomy University of Cape Town d.p.rtment of physics University of the Free State Université paris Cité CNRS Astroparticule et Cosmologie Université paris Cité CEA paris-Saclay IRFU/d.p.AIM d.p.rtment of Astronomy Guangzhou University Cosmic dawn Center (dAwN) Niels Bohr Institute University of Copenhagen d.p.rtment of physics and Astronomy Rutgers the State University of New Jersey Institute for Cosmic Ray Research The University of Tokyo ESA/ESTEC d.p.rtment of Astronomy School of physics huazhong University of Science and Technology INAF-Osservatorio Astrofisico di Torino Sydney Institute for Astronomy School of physics The University of Sydney d.p.rtment of Astronomy Xiamen University Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University d.p.rtment of Astronomy University of Science and Technology School of Astronomy and Space Sciences University of Science and Technology of China Institute of deep Space Sciences deep Space Exploration Laboratory d.p.rtment of Astronomy School of physics and Astronomy Yunnan University Shanghai Astronomical Observatory Chi

we report the discovery of a peculiar X-ray transient,Ep240408a,by Einstein probe （Ep） and follow-up studies made with Ep,Swift,NICER,GRONd,ATCA and other ground-based multiwavelength *** new transient was first detected with.w.de-field X-ray Telescope （wXT） on board Ep on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for *** flare reached a peak flux of 3.9×10-9erg cm-2s-1in 0.5-4 ke V,～300 times brighter than the underlying X-ray emission detected throughout the *** and more precise follow-up observations by Ep/FXT,Swift and NICER confirmed the finding of this new *** X-ray spectrum is non-thermal in 0.5-10 ke V,with a power-law photon index varying *** X-ray light curve sh.w. a plateau lasting for ～4 d,followed by a steep decay till becoming undetectable ～10 d after the initial *** on its temporal property and constraints from previous Ep observations,an unusual timescale in the range of 7-23 d is found for Ep240408a,which is intermediate between the commonly found fast and long-term *** counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these *** demonstrate that the remarkable properties of Ep240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical *** nature of Ep240408a thus remains an *** suggest that Ep240408a may represent a new type of transients with intermediate timescales of the order of～10 *** detection and follow-ups of more of such objects are essential for revealing their origin.

关键词： X-ray transients ${\bm~{Einstein~~probe}}$

Experimental Studieson Gas－particle Flows and Coal Combustion in New Generation Spouting－Cyclone Combustor

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Journal of Thermal Science 1996年第2期5卷 132-137页

作者： d.X. wang z.h. Ma X.L. wang L.X. zhou(d.p.rtment of Engineering Mechanics,Tsinghua University, Beijing 100084, China) d.p.rtment of Engineering Mechanics Tsinghua University Beijing China

Based on previous studies,an improved non-slagging spouting-cyclone combustor with two-stage combustion, organized in perpendicularly vortexing flows, is developed for clean coal combustion applied in small-size industrial furnaces and domestic furnaces. The isothermal model test and the combustion test give some encouraging results. In this studyt further improvement of the geometrical configuration was made, a visualizatiou method and a LdA system were used to study the gas-particle flow behavior,and the temperature and gas composition in combustion experiments were measured by using thermocouples and a COSA-6000-Cd.p.rtable Stack Analyzer. Stronger recirculation in the spouting zone and the strongly swirling effect in the cyclone zone were obtained in the improved combustor. The combustion temperature distribution is uniform. These results indicate that the improved geometrical configuration of the combustor is favorable to the stabilization of coal flame and the intensification of coal combustion, and it provides a basis for the practical application of this technique.

关键词： strongly swirling flows LdA measurement combustion

Three-dimensional structure of the inner core of rice dwarf virus

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Science China(Life Sciences) 2001年第2期44卷 192-198页

作者：邵承华 z.h.zhou 卢光莹 1. National Laboratory of protein Engineering and.p.ant Genetic Engineering College of Life Sciences Peking University 100871 Beijing China 2. d.p.rtment of pathology and Laboratory Medicine Houston Medical School University of Texas 77030 Houston TX USA

Rice dwarf virus (RdV) is a double-shelled icosahedral virus. Using electron cryomicro-scopy and computer reconstruction techniques, we have determined a 3.3 nm resolution three-dimensional (3d) structure of the inner shell capsid without the outer shell and viral RNA. The results sh.w.that the inner shell is a thin, densely packed, smooth structure, which provides a scaffold for the full virus. A total of 120 copies of the major inner shell capsid.p.otein p3 forms 60 dimers arranged in a T=1 icosahedral lattice. A close examination on the subunit packing of the T=1 inner core p3 with that of the T=13/ outer shell p8 indicated that p8 trimers connect with p3 through completely non-equivalent, yet highly specific, intermolecular interactions.

关键词： rice dwarf virus inner core three-dimensional structure.