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Deformation behavior of Mg-y-Ni alloys containing different volume fraction of LPSO phase during tension and compression through in-situ synchrotron diffraction

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Journal of Magnesium and Alloys 2024年第9期12卷 3631-3645页

作者： S.Z.Wu y.Q.Chi g.garces X.H.Zhou H.g.Brokmeier X.g.Qiao M.y.Zheng School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006China Department of Physical Metallurgy CENIM-CSICAvenida Gregorio del Amo 828040 MadridSpain Institute of Materials Science and Engineering Clausthal University of TechnologyAgricolastrasse 6D-38678 Clausthal-ZellerfeldGermany

The deformation behavior of the as-extruded Mg-y-Ni alloys with different volume fraction of long period stacking ordered(LPSO)phase during tension and compression was investigated by in-situ synchrotron *** micro-yielding,macro-yielding,tension-compression asymmetry and strain hardening behavior of the alloys were explored by combining with deformation *** micro-yielding is dominated by basal slip of dynamic recrystallized(DRXed)grains in tension,while it is dominated by extension twinning of non-dynamic recrystallized(non-DRXed)grains in *** macro-yielding,the non-DRXed grains are still elastic deformed in tension and the basal slip of DRXed grains in compression are ***,the LPSO phase still retains elastic deformation,but can bear more load,so the higher the volume fraction of hard LPSO phase,the higher the tensile/compressive macro-yield strength of the *** from the low volume fraction of the non-DRXed grains and the delay effect of LPSO andγphases on extension twinning,the as-extruded alloys exhibit excellent tension-compression *** the volume fraction of LPSO phase reaches∼50%,tension-compression asymmetry is reversed,which is due to the fact that the LPSO phase is stronger in compression than in *** tensile strain hardening behavior is dominated by dislocation slip,while the dominate mechanism for compressive strain hardening changes from twinning in theα-Mg grains to kinking of the LPSO phase with increasing volume fraction of LPSO *** activation of kinking leads to the constant compressive strain hardening rate of∼2500 MPa,which is significantly higher than the tensile strain hardening rate.

关键词： Mg-y-Ni alloys LPSO phase In-situ synchrotron diffraction Micro-yielding Tensile-compression asymmetry Strain hardening

PARAMAgNETIC MEISSNER EFFECTS IN MELT-TEXTURED y_(0.99)Nd_(0.01)Ba_2Cu_3O_(7-y)SUPERCONDUCTOR

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Acta Metallurgica Sinica(English Letters) 2002年第3期15卷 295-298页

作者： y.T. Xing y.Z. wang g.W. Qiao Institute of Metal Research The Chinese Academy of Sciences Shenyang 110016 China

The paramagnetic Meissner effect (PME) was observed on the field-cooled M-T curves of melt-textured y0.99Nd0.01Ba2Cu3O7-y in applied magnetic fields from 1kOe to 40kOe. In the magnetic field below 1kOe, the sample undergoes the typical transition from the normal state to the superconducting state when it was cooled down. The applied magnetic fields in which the PME occurs, are very high compared with the fields reported in literatures. We propose that the occurrence of the PME may be due to a phase transition of flux vortices in the superconductors.

关键词： yBCO superconductor paramagnetic Meissner effect (PME)

Ultrahigh strength Mg-y-Ni alloys obtained by regulating second phases

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Journal of Materials Science & Technology 2020年第10期42卷 117-124页

作者： S.Z.Wu X.g.Qiao M.y.Zheng School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

Mg-y-Ni alloys with different second phases were designed by changing y/Ni atomic ratio from 1.5 to *** microstructure and mechanical properties of as-cast and as-extruded alloys were *** as-cast Mg-y-Ni alloy with y/Ni ratio of 1.5 is composed ofα-Mg and long period stacking ordered(LPSO)*** y/Ni ratio is equal to 1,nanoscale lamellarγ’phase and eutectic Mg2Ni phase are formed in addition to LPSO *** y/Ni ratio decreases further,the amount of eutectic Mg2Ni phase increases,while the amount of LPSO phase *** extrusion,the LPSO andγ’phases are distributed along the extrusion direction,while eutectic Mg2Ni phase is broken and dispersed in the as-extruded *** phase and Mg2Ni phase in the alloys promote dynamic recrystallization(DRX)during extrusion,whileγ’phase inhibits ***,the Mg96y2Ni2(at.%)alloy with LPSO phase andγ’phase as the main second phases shows the strongest basal texture after *** tensile yield strength of the as-extruded Mg-y-Ni alloys increases first and then decreases with decreasing y/Ni *** as-extruded Mg96y2Ni2(at.%)alloy with y/Ni=1 exhibits excellent mechanical properties with tensile yield strength of 465 MPa,ultimate tensile strength of 510 MPa and elongation to failure of 7.2%,which is attributed to the synergistic effect of bulk LPSO phase and nanoscaleγ’phase.

关键词： Mg-y-Ni alloys LPSO γ’Phase Mg2Ni Mechanical properties

Effect of y Addition on Microstructure and Mechanical Properties of Friction Stir Welded ZK60 Alloy

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Journal of Materials Science & Technology 2009年第3期25卷 351-355页

作者： g.M. Xie Z.y. Ma L. geng School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

6 mm thick ZK60 and ZK60-y alloy plates were successfully friction stir welded （FSW） at a tool rotation rate of 1200 r/min and a traverse speed of 100 mm/min. FSW resulted in the dissolution of MgZn2 particles in the ZK60 and the breakup and dispersion of W-phase （Mg3Zn3y2） particles in the ZK60-y alloy, thereby leading; to a decrease in the hardness of the nugget zone （NZ） for the ZK60 alloy and an increase in the hardness of the NZ for the ZK60-y alloy, respectively. While two FSW joints exhibited similar joint efficiency （87%-89% of ultimate tensile strengths of the parent materials）, the yield strength of the FSW ZK60-y joint was substantially higher than that of the FSW ZK60 joint. The fracture occurred in the NZ and the heat affected zone for the ZK60 and ZK60-y joints, respectively, which were consistent with the lowest hardness distribution of the welded joints.

关键词： Friction stir welding Magnesium Microstructure Mechanical properties

Exercise preconditioning alleviates ischemia-induced memory deficits by increasing circulating adiponectin

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Neural Regeneration Research 2025年第5期20卷 1445-1454页

作者： Meifeng Zheng Borui Zhang Sonata S y yau Kwok-Fai So Li Zhang Haining Ou Department of Rehabilitation Medicine Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina Department of Rehabilitation Medicine The Fifth Clinical College of Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina Key Laboratory of CNS Regeneration(Ministry of Education) Guangdong-Hong Kong-Macao Institute of CNS RegenerationJinan UniversityGuangzhouGuangdong ProvinceChina Department of Rehabilitation Sciences The Hong Kong Polytechnic UniversityHong Kong Special Administrative RegionChina State Key Laboratory of Brain and Cognitive Science Li Ka Shing Faculty of MedicineThe University of Hong KongHong Kong Special Administrative RegionChina Center for Exercise and Brain Science School of PsychologyShanghai University of SportShanghaiChina Neuroscience and Neurorehabilitation Institute University of Health and Rehabilitation SciencesQingdaoShandong ProvinceChina

Cerebral ischemia is a major health risk that requires preventive approaches in addition to drug *** exercise enhances neurogenesis and synaptogenesis,and has been widely used for functional rehabilitation after *** this study,we determined whether exercise training before disease onset can alleviate the severity of cerebral *** also examined the role of exercise-induced circulating factors in these *** mice were subjected to 14 days of treadmill exercise training before surgery for middle cerebral artery *** found that this exercise pre-conditioning strategy effectively attenuated brain infarct area,inhibited gliogenesis,protected synaptic proteins,and improved novel object and spatial memory *** analysis showed that circulating adiponectin plays a critical role in these preventive effects of *** activation of adiponectin receptors by Adipo Ron mimicked the effects of exercise,while inhibiting receptor activation abolished the exercise *** summary,our results suggest a crucial role of circulating adiponectin in the effects of exercise pre-conditioning in protecting against cerebral ischemia and supporting the health benefits of exercise.

关键词： adiponectin cerebral ischemia exercise pre-conditioning hippocampus memory function middle cerebral artery occlusion prefrontal cortex synaptic proteins treadmill exercise

Effect of Rotation Rate on Microstructures and Mechanical Properties of FSW Mg-Zn-y-Zr Alloy Joints

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Journal of Materials Science & Technology 2011年第12期27卷 1157-1164页

作者： g.M. Xie Z.y. Ma Z.A. Luo P. Xue g.D. wang The State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110819 China Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of SciencesShenyang 110016 China

Friction stir welding （FSW） of Mg-Zn-y-Zr plates with 6 mm in thickness was successfully carried out under a wide range of rotation rates of 600-1200 r/rain with a constant traverse speed of 100 mm/min. After FSW, the coarse grains in the parent material （PM） were changed into fine equiaxed recrystallized grains at the＇nugget zone （NZ）. Furthermore, the coarse Mg-Zn-y particles （W-phase） were broken up and dispersed homogenously into the Mg matrix. With increasing rotation rates, the size of the W-phase particles at the NZ significantly decreased, but the recrystallized grain size tended to increase. The hardness values of the NZs for all the FSW joints were higher than those of the PM, and the lowest hardness values were detected in the heat affected zone （HAZ）. The fracture occurred in the thermo-mechanical affected zone （TMAZ） on the advancing side for all the FSW joints in the tensile test, due to the incompatibility of the plastic deformation between the NZ and TMAZ caused by remarkably different orientation of grains and W-phase particles. The strength of FEW ioint reaches 90% of that of its PM

关键词： Friction stir welding Magnesium alloys Microstructure Mechanical property

gene therapy for spinal muscular atrophy:perspectives on the possibility of optimizing SMN1 delivery to correct all neurological and systemic perturbations

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Neural Regeneration Research 2025年第7期20卷 2011-2012页

作者： Sharon J.Brown Rafael J.yáñez-Muñoz Heidi R.Fuller School of Pharmacy and Bioengineering Keele UniversityKeeleUK Wolfson Center for Inherited Neuromuscular Disease TORCH BuildingRJAH Orthopaedic HospitalOswestryUK *** Center of Gene and Cell TherapyDepartment of Biological SciencesSchool of Life Sciences and the EnvironmentRoyal Holloway University of LondonEghamUK

Spinal muscular atrophy(SMA)is a genetic condition that results in selective lower motor neuron loss with concomitant muscle weakness and *** genetic cause of SMA was understood in 1995 when loss or impairment of the survival motor neuron 1(SMN1)gene was identified as the main contributing factor(Lefebvre et al.,1995).This,in combination with the discovery that humans have a“back-up”gene,SMN2,which can produce low levels(approximately 10%)of the full-length functional SMN protein,has led to the generation of SMA-specific gene *** was traditionally classified according to age of symptom onset and developmental milestones achieved,with life expectancy and severity varying between ***,SMN2 copy number is used as a proxy for the prediction of disease severity,with higher SMN2 copy number typically being associated with reduced severity of SMA,although this relationship is not absolute:some individuals with low SMN2 copy number have less severe SMA phenotypes and vice ***,the etiology of SMA is further complicated by other factors,such as non-typical nucleotide variants and SMN2-independent modifiers of disease severity.

关键词： atrophy traditionally absolute

Active elastic metamaterials for subwavelength wave propagation control

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Acta Mechanica Sinica 2015年第3期31卷 349-363页

作者： y.y.Chen g.L.Huang Department of Mechanical and Aerospace Engineering University of Missouri

Recent research activities in elastic metamaterials demonstrate a significant potential for subwavelength wave propagation control owing to their interior locally resonant mechanism. The growing technological developments in electro/magnetomechanical couplings of smart materials have introduced a controlling degree of freedom for passive elastic metamaterials. Active elastic metamaterials could allow for a fine control of material physical behavior and thereby induce new functional properties that cannot be produced by passive approaches. In this paper, two types of active elastic metamaterials with shunted piezoelectric materials and electrorheological elastomers are proposed. Theoretical analyses and numerical validations of the active elastic metamaterials with detailed microstructures are pre- sented for designing adaptive applications in band gap structures and extraordinary waveguides. The active elastic metamaterial could provide a new design methodology for adaptive wave filters, high signal-to-noise sensors, and structural health monitoring applications.

关键词： Active elastic metamaterials Subwavelengthwave control Adaptive metastructures Smart materials

Corrosion behavior of 13Cr stainless steel under stress and crevice in high pressure CO_(2)/O_(2)environment

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Journal of Materials Science & Technology 2021年第29期88卷 79-89页

作者： g.y.Zhu y.y.Li B.S.Hou Q.H.Zhang g.A.Zhang Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of EducationHubei Key Laboratory of Materials Chemistry and Service FailureSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074China

In this work,through the self-developed setup for in situ electrochemical tests,the corrosion behavior of 13 Cr stainless steel under the combined effect of stress and crevice in high pressure CO_(2)/O_(2)environment was *** results show that 13 Cr stainless steel presents a self-passivation *** the action of stress,the anodic dissolution process of steel inside crevice is *** is a galvanic effect between the stressed steel inside crevice and the unstressed steel outside *** applied stress reduces the induction stage of crevice corrosion and induces a larger galvanic current,i.e.,the applied stress promotes the development of crevice ***,adding 0.1 MPa O_(2)is conducive to forming a more stable passive film but causes a greater galvanic effect.

关键词： Stainless steel Crevice corrosion Stress corrosion galvanic effect