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China Foundry 2016年第3期13卷 176-181页

作者： Yao-qiang Si zhi-yong you Jing-xin Zhu Lai-qiang Cai Jin-shan Zhang College of Materials Science and Engineering Taiyuan University of Technology

Aluminum matrix composites reinforced with mechanical alloying particles(SiC_p) were fabricated by the semisolid stirring pouring method. The inf luence of mechanical alloying particles and Mg on the microstructure and mechanical properties of the composites was investigated by means of optical microscopy(OM), X-ray diffraction scanning(XRD), electron microscopy(SEM) and energy dispersive spectroscopy(EDS). Results show that the addition of Mg converts the agglomerate mechanical al oying particles in ZL101 matrix composites into dispersed distribution in ZL101-Mg matrix composites, large matrix grains into f ine equiaxed matrix grains, and eutectic phase into f ine particles. So the mechanical properties of ZL101-Mg matrix composites are better than those of ZL101 matrix composites. The mechanical properties of ZL101/ZL101-Mg matrix composites are gradually increased with the increase of the volume fraction of mechanical alloying particles. When the volume fraction of mechanical alloying particles is 3%, the Vickers hardness and ultimate tensile strength of the ZL101/ZL101-Mg matrix composites reach their maximum values.

关键词： mechanical alloying particle aluminum matrix composites grain refinement mechanical properties

Effect of Li on formation of long period stacking ordered phases and mechanical properties of Mg-Gd-Zn alloy

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China Foundry 2016年第4期13卷 256-261页

作者： Li-yun Wei Jin-shan Zhang Wei Liu Chun-xiang Xu zhi-yong you Kai-bo Nie College of Materials Science and Engineering Taiyuan University of Technology Taiyuan 030024 China Shanxi Key Laboratory of Advanced Magnesium-based Materials Taiyuan 030024 China

Alloys with composition of Mg_(96-x)Gd_3Zn_1Li_x(at.%)(x=0, 2, 4, and 6) were prepared by conventional casting. The microstructures of these alloys under as-cast and solid-solution conditions have been observed, and the mechanical properties were investigated. The results showed that Li is an effective element to refine the grains and break the eutectic networks in as-cast MgGd_3Zn_1 alloy. During solid solution treatment, these broken eutectic networks are spheroidized and highly dispersed. In addition, plentiful lamellar long period stacking ordered(LPSO) phases are precipitated in an α-Mg matrix when the Li addition is not more than 4%. Solid-solution treated Mg_(92)Gd_3Zn_1Li_4 alloy exhibits an optimal ultimate tensile strength(UTS) of 226 MPa and elongation of 5.8%. The strength of MgGd_3Zn_1 alloy is improved significantly, meanwhile, the toughness is apparently increased.

关键词： Mg-Gd-Zn alloys Li second phase long period stacking ordered phase comprehensive properties

Effect of heat treatment on microstructure and properties of semi-solid squeeze casting AZ91D

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China Foundry 2020年第3期17卷 219-226页

作者： zhi-yong you Ao-xue Jiang Zhuang-zheng Duan Gang-ping Qiao Jing-lei Gao Ling-bing Guo College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi Huaxiang Group Co. Ltd.Linfen 011600China

Semi-solid AZ91D magnesium alloy billets were prepared by near-liquidus heat ***-solid squeeze casting was conducted at 575,585 and 595℃,respectively,with 1 mm·s^-1 squeeze *** semisolid squeeze casting AZ91D samples were heat treated by T4(solution at 415℃for 24 h)and T6(solution at 415℃for 24 h+220℃for 8 h)processes,*** microstructure and mechanical properties of the alloy in different states were investigated by means of OM,SEM and tensile testing *** results show that compared to as-cast alloy,the grain size of the semi-solid squeezed AZ91D decreased significantly,and with the increase of semi-solid squeeze temperature,the grain size of AZ91D *** grains of the alloy were refined by T4 treatment,and further refined by T6 treatment.T6 treatment greatly improved the tensile strength,elongation,and hardness,but did not significantly improve yield *** 575℃squeeze casting and T6 treatment,the ultimate tensile strength(UTS)reached 285 MPa,the elongation reached 13.36%,and the hardness also reached the maximum(106.8 HV),but the yield strength(YS)was only 180 *** the process of semi-solid squeeze casting and heat treatment,the matrix grain was refined and a large number of precipitated and secondary precipitated phases of Mg17Al12 *** the average size of matrix grain and secondary precipitated phase decreased,while the volume fraction of secondary precipitated phase *** these resulted in high tensile strength,elongation and hardness.

关键词： AZ91D semi-solid squeeze casting solution aging treatment microstructure mechanical properties

Effects of SiC_(p) on microstructures of semi-solid extruded AZ91D magnesium alloys in recrystallization process

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China Foundry 2021年第6期18卷 565-573页

作者： Ao-xue Jiang zhi-yong you Zhuang-zheng Duan Gang-ping Qiao Jin-shan Zhang Ling-bing Guo College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi Huaxiang Group Co. Ltd.Linfen 041000ShanxiChina

AZ91 D and 8.5 vol.%SiC_(p)/AZ91 D magnesium matrix composites were fabricated by a semi-solid extruded processing method,and treated with solution and aging heat *** effects of SiC_(p)on the microstructures of the semi-solid extruded AZ91 D magnesium alloy during recrystallization were studied by observing and analyzing the microstructure evolution during extrusions and heat *** results show that the addition of SiC_(p)inhibits the dynamic recrystallization of AZ91 D during the semi-solid extrusion with only 26% of the volume fraction of ***,the addition of SiC_(p)refines the sizes of grains and second phases,and upgrades the volume fraction of second *** solution and aging treatment,the recrystallization continues,and the addition of SiC_(p)promotes the recrystallization and the recrystallized microstructure is much more ***,the sizes of grains and second phases continue to be refined,and the volume fraction of second phases continues to increase.

关键词： SiC_(p)/AZ91D composites semi-solid extrusion recrystallization microstructure

Tailoring the microstructural characteristics and enhancing creep properties of as-cast Mg-5Bi-5Sn alloy through Mn addition

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Journal of Magnesium and Alloys 2023年第9期11卷 3350-3361页

作者： Yi-hao Luo Wei-li Cheng Hui Yu Hong-xia Wang Xiao-feng Niu Li-fei Wang Hang Li zhi-yong you Hua Hou School of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education Taiyuan University of TechnologyTaiyuan 030024China School of Materials Science and Engineering Hebei University of TechnologyTianjin 300132China School of Materials Science and Engineering North University of ChinaTaiyuan 030051China

The creep properties, microstructural characteristics and creep mechanisms of as-cast Mg-5Bi-5Sn(BT55) alloy without and with Mn(BTM550) addition were investigated via creep at 423, 448, and 473 K as well as stresses of 30, 50 and 75 MPa. The results indicate that adding Mn can result in the formation of primary and the dynamic precipitated α-Mn phases. In addition, the morphology of the precipitated Mg_(3)Bi_(2) phase and the orientation relationship between Mg_(2)Sn precipitates and α-Mg can be effectively modified. Tailoring the microstructural characteristics is responsible for the improved creep performance of BTM550 alloy. The dominant creep mechanisms in BT55 and BTM550 alloys are dislocation cross-slip and climb, respectively. Furthermore, twinning and pyramidal slip play an assisting part in both alloys during creep process.

关键词： Mg alloy Microstructural characteristics Creep properties Precipitates Dislocation

Microstructure and mechanical properties of a compound reinforced Mg95Y2.5Zn2.5 alloy with long period stacking ordered phase and W phase

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China Foundry 2017年第1期14卷 34-38页

作者： Shou-zhong Wu Jin-shan Zhang Chun-xiang Xu Kai-bo Nie Xiao-feng Niu zhi-yong you College of Materials Science and Engineering Taiyuan University of TechnologyTaoyuan 030024China Shanxi Key Laboratory of Advanced Magnesium-based Materials Taiyuan 030024China

The microstructure evolution of Mg100-2xYxZnx （x=2, 2.5, 3, 3.5） alloys was investigated. Results show that the Mg100-2xYxZnx alloys are composed of a-Mg, long period stacking ordered （LPSO） phase and eutectic structure phase （W phase）, and the Mg95Y2.5Zn2.5 alloy has the best comprehensive mechanical properties. Subsequently, the microstructure evolution of the optimized alloy Mg95Y2.5Zn2.5 during solidification and heat treatment processes was analyzed and discussed by means of OM, SEM, TEM, XRD and DTA. After heat treatment, the lamellar phase 14H-LPSO precipitated in a-Mg and W phase transforms into particle phase （MgyZn2）. Due to the compound reinforcement effect of the particle phase and LPSO phase （18R＋14H）, the mechanical properties of the alloy are enhanced. The tensile strength and elongation of the Mg95Y2.5Zn2.5 alloy is improved by 9.1% and 31.3% to 215 MPa and 10.5%, respectively, after solid-solution treatment.

关键词： magnesium alloys Mg95Y2.5Zn2.5 alloy long period stacking ordered (LPSO) W phase compound reinforcement

Small interfering RNA of cyclooxygenase-2 induces growth inhibition and apoptosis independently of Bcl-2 in human myeloma RPMI8226 cells

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Acta Pharmacologica Sinica 2007年第7期28卷 1031-1036页

作者： Qiu-bai LI zhi-chao CHEN yong you Ping ZOU Department of Hematology,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology,Wuhan 430022,China Department of Hematology Union Hospital Tongji Medical College HuazhongUniversity of Science and Technology Wuhan 430022 China. doctorlee007@***.

Aim:To investigate the effects of small interfering RNA of cyclooxygenase-2(COX-2) on the proliferation and apoptosis of human multiple myeloma RPMI8226cells and its relation with the Bcl-2 family in ***:Transcription andexpression of COX-2 in human myeloma RPMI8226 cells were checked by RT-PCRand Western blot analysis,*** COX-2 siRNA fragment targetingexon 5 of COX-2 gene was transfected into the cells with the Amaxa *** inhibition of cell growth was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) *** was estimatedby Annexin-V/propidium iodide double-labeled cytometry and confirmed by termi-nal deoxynucleotidyl transferase-mediated dUTP nick end-labeling ***-2and Bax expression was evaluated by Western blot ***:The COX-2siRNA fragment could be successfully transfected into RPMI8226 cells,whichresulted in the significant inhibition of transcription and expression of COX-2 inthe myeloma *** of the transfected cells was inhibited andapoptosis was induced (6.52%±0.32%,12.53%±2.52%,24.39%±3.51% and36.48%±4.96% for 0,12,24,and 48 h,respectively) in a time-dependent manner(P<0.01).However,the expression of Bcl-2 and Bax in the RPMI8226 cells had nosignificant changes after ***:COX-2 siRNA transfectioncan suppress COX-2 expression in human myeloma RPMI8226 cells,which leadsto growth inhibition and apoptosis independent of Bcl-2.

关键词： RPMI8226 small interfering RNA apoptosis proliferation

Effects ofslip mode on microstructure evolution and compressive flow behavior of extruded dilute Mg−0.5Bi−0.5Sn−0.5Mn alloy

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Transactions of Nonferrous Metals Society of China 2024年第11期34卷 3599-3614页

作者： zhi-yong you Wei-li CHENG Guo-lei LIU Jian LI Li-fei WANG Hui YU Hong-xia WANG Ze-qin CUI Jin-hui WANG School of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Salt Lake Chemical Engineering Research Complex Qinghai UniversityXining 810016China School of Materials Science and Engineering Hebei University of TechnologyTianjin 300132China

The influence of the slip mode on the microstructure evolution and compressive flow behavior at different strains in an extruded dilute Mg−0.5Bi−0.5Sn−0.5Mn alloy was analyzed through electron backscatter diffraction,X-ray diffraction,transmission electron microscopy,and hot compression *** results showed that at a low strain of 0.05,the basal,pyramidalandslip modes were simultaneously ***,at the middle stage of deformation(strain of 0.1,0.2 and 0.5),theslip mode was difficult to be activated andslip mode became *** deformation process between strains of 0.2 and 0.5 was primarily characterized by the softening effect resulting from the simultaneous occurrence of continuous dynamic recrystallization and discontinuous dynamic ***,at strain of 0.8,a dynamic equilibrium was established,with the flow stress remaining constant due to the interplay between the dynamic softening brought about by discontinuous dynamic recrystallization and the work-hardening effect induced by the activation of the basalslip mode.

关键词： dilute Mg−Bi−Sn−Mn alloy slip mode hot compression flow behavior dynamic recrystallization

Deciphering the role of ultra-low-loaded rhodium in NiFe-MIL-53 for superior oxygen evolution reaction

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Journal of Energy Chemistry 2025年第1期100卷 77-86页

作者： Jinzhi Jia Jinhua Zhang Kailu Guo Lanyue Zhang Gening Du Hao you Junfeng Huang Mudong Tu Hua Li yong Peng Wei Dou Cailing Xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering School of Materials and Energy Lanzhou University College of Chemistry and Chemical Engineering Luoyang Normal University

Designing highly active and stable electrocatalysts of oxygen evolution reaction （OER） is one of the crucial *** this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium（Rh@NiFe-MIL-53）,is successfully prepared via the hydrothermal ***-situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the doped Rh accelerates the phase transformation of NiFe-MIL-53 and the in-situ formed Rh@NiFeOOH is the actual active *** importantly,the enhanced reversibility of electrochemical reconstruction between NiFeOOH and NiFe（OH）2after doping Rh is beneficial for improving the electrochemical stability of the catalyst.X-ray photoelectron spectroscopy spectra show the strong electronic interaction between single-atom Rh and Ni/Fe in Rh@***,theoretical calculations confirm that the integration of single-atom Rh into the NiFeOOH successfully reduces the band gap,regulates the d-band center （εd）,accelerates the charge transfer,and optimizes the adsorption behavior of oxygen-containing intermediates,thereby lowering the energy barrier of rate-determining ***,the optimized Rh@NiFe-MIL-53 exhibits excellent OER activity （240 mV） with a small Tafel slope of 48.2 mV dec-1and long-term durability (over1270 h at 10 m A cm-2and 110 h at 200 mA cm-2).This work presents a new perspective on designing highly efficient OER electrocatalysts.

关键词： NiFe-MIL-53 Rh Electrochemical reconstruction Catalytic mechanism Oxygen evolution reaction

Record-breaking bifunctional oxygen electrocatalyst accomplished by a data-driven approach for zinc-air batteries

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Journal of Energy Chemistry 2025年第1期100卷 144-145页

作者： Deviprasath Chinnadurai zhi Wei Seh Institute of Materials Research and Engineering (IMRE) Agency for Science Technology and Research (A*STAR)

Rechargeable zinc-air batteries(ZABs) have recently drawn great attention in energy research due to their high theoretical capacity,low costs, and inherently safe nature [1–3]. However, the sluggish cathode reactions necessitate the development of bifunctional oxygen electrocatalysts with lower ΔE indicator values. The ΔE indicator is commonly employed to quantitatively evaluate the electrocatalytic activity of a bifunctional oxygen electrocatalyst,representing the overall overpotential from oxygen reduction reaction(ORR) to oxygen evolution reaction(OER).

关键词： Data-driven approach Bifunctional oxygen electrocatalyst Record breaking performance Zinc-air batteries