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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.

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 National Laboratory of protein Engineering and.p.ant Genetic Engineering College of Life Sciences Peking University Beijing China d.p.rtment of pathology and Laboratory Medicine Houston Medical School University of Texas Houston 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.

山姜素调节cAMp/pKA/CREB信号通路促进骨质疏松性骨折大鼠骨折愈合

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中国组织工程研究 2025年第12期29卷 2438-2443页

作者：陆飞周静金涛连云港市第一人民医院康复医学科江苏省连云港市222000 南京医科大学康达学院康复医学部江苏省连云港市222000 中国人民解放军东部战区总医院健康医学科江苏省南京市210018

背景:山姜素具有抗炎、抗肿瘤、抗菌等作用,已被证实能够缓解骨质疏松症,但山姜素对骨质疏松性骨折的影响及机制仍不清楚。目的:探讨山姜素调节环磷酸腺苷/蛋白激酶A/环磷酸腺苷反应元件结合蛋白信号通路对骨质疏松性骨折大鼠的改善作... 详细信息

背景:山姜素具有抗炎、抗肿瘤、抗菌等作用,已被证实能够缓解骨质疏松症,但山姜素对骨质疏松性骨折的影响及机制仍不清楚。目的:探讨山姜素调节环磷酸腺苷/蛋白激酶A/环磷酸腺苷反应元件结合蛋白信号通路对骨质疏松性骨折大鼠的改善作用。方法:采用双侧卵巢切除手术构建骨质疏松症骨折大鼠模型,将成功造模大鼠依据随机数字表法分为山姜素低、中、高剂量组、抑制剂组和模型组,另选12只大鼠作为假手术组。骨折造模当天,山姜素低、中、高剂量组大鼠灌胃7.5,15,30 mg/kg的山姜素+腹腔注射等量的生理盐水,抑制剂组灌胃30 mg/kg的山姜素+腹腔注射5 mg/kg的h-89(通路抑制剂),模型组与假手术组给予(灌胃+腹腔注射)等量生理盐水,1次/d,连续8周。放射性检查评估大鼠骨折愈合情况并进行愈合评分;骨密度扫描仪测定骨折处骨密度;通过三点弯曲实验和压缩实验评估大鼠股骨生物力学状况;苏木精-伊红染色观察大鼠骨折处病理损伤;酶联免疫吸附(ELISA)法检测血清碱性磷酸酶、骨钙素和Ⅰ型胶原交联C-末端肽、环磷酸腺苷水平的变化;western blot检测股骨组织中骨形态发生蛋白2和环磷酸腺苷/蛋白激酶A/环磷酸腺苷反应元件结合蛋白通路蛋白表达。结果与结论:①相较于假手术组,模型组大鼠骨折愈合评分、骨密度、最大负荷、最大应力、碱性磷酸酶、骨钙素、环磷酸腺苷水平、骨形态发生蛋白2、磷酸化蛋白激酶A/蛋白激酶A、磷酸化环磷酸腺苷反应元件结合蛋白/环磷酸腺苷反应元件结合蛋白表达下降,Ⅰ型胶原交联羧基末端肽水平增加(ppp<0.05)。②结论:山姜素可能通过激活环磷酸腺苷/蛋白激酶A/环磷酸腺苷反应元件结合蛋白信号通路加速骨质疏松症骨折大鼠的骨折愈合。

关键词：山姜素环磷酸腺苷/蛋白激酶A/环磷酸腺苷反应元件结合蛋白骨质疏松骨折愈合大鼠