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Science China Mathematics 2023年

作者： min Liang Yaobin ou School of Mathematics Renmin University of China

This paper verifies the low Mach number limit of the non-isentropic compressible magnetohydrodynamic (MHD) equations with or without the magnetic diffusion in a three-dimensional bounded domain when the temperature variation is large but finite. The uniform estimates of strong solutions are established in a short time interval independent of the Mach number, provided that the slip boundary condition for the velocity and the Neumann boundary condition for the temperature are imposed and the initial data is well-prepared.

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A survey on numerical simulations of drag and heat reduction mechanism in supersonic/hypersonic flows

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Chinese Journal of Aeronautics 2019年第4期32卷 771-784页

作者： Xiwan SUN Wei HUANG Min ou Ruirui ZHANG Shibin LI College of Aerospace Science and Engineering National University of Defense Technology National Innovation Institute of Defense Technology Chinese Academy of Military Sciences

Along with the survey on experimental investigations drawing attention to the drag and heat reduction mechanism, the authors simultaneously focus on the recent advances of numerical simulations on the schemes applied to supersonic/hypersonic vehicles. The CFD study has evolved as an irreplaceable method in scheme evaluation and aircraft optimization. Similar to our previous experimental survey, the advances in drag and heat reduction schemes are reviewed by similar kinds of mechanism in this article, namely the forward-facing cavity, the opposing jet, the aerospike, the energy deposition and their combinational configurations. This review article puts an emphatic eye on the flow conditions, numerical methods, novel schemes and analytical conclusions given in the simulations. Further, the multi-objective design optimization concept has also been illustrated due to the observable advantages of using CFD over experimental method, especially those performances conducted in drag reduction and thermal protection practice, and this would possess reference value in the design of aircraft system.

关键词： Aerospike Drag and heat reduction Energy deposition Forward-facing cavity Opposing jet

The low Mach number limit of non-isentropic magnetohydrodynamic equations with large temperature variations in bounded domains

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Science China Mathematics 2024年第4期67卷 787-818页

作者： min Liang Yaobin ou School of Mathematics Renmin University of ChinaBeijing 100872China

This paper verifies the low Mach number limit of the non-isentropic compressible magnetohydrodynamic(MHD)equations with or without the magnetic diffusion in a three-dimensional bounded domain when the temperature variation is large but finite.The uniform estimates of strong solutions are established in a short time interval independent of the Mach number,provided that the slip boundary condition for the velocity and the Neumann boundary condition for the temperature are imposed and the initial data is well-prepared.

关键词： low Mach number limit non-isentropic compressible magnetohydrodynamic equations large temperature variations bounded domains

Development and application of a life cycle energy consumption and CO2emissions analysis model for high-speed railway transport in China

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Advances in Climate Change Research 2021年第2期12卷 270-280页

作者： WANG Yan-Zhe ZHou Sheng ou Xun-min Tsinghua University-Zhang Jiagang Joint Institute for Hydrogen Energy and Lithium-Ion Battery Technology Tsinghua UniversityBeijing100084China Institute of Energy Environment and EconomyTsinghua UniversityBeijing100084China Tsinghua-Rio Tinto Joint Research Centre for Resources Energy and Sustainable DevelopmentLaboratory for Low Carbon EnergyTsinghua UniversityBeijing100084China China Automotive Energy Research Center Tsinghua UniversityBeijing100084China

China's high-speed railway(HSR)is booming recently,the HSR's performance of energy conservation and carbon reduction has attractedmuch attention.This study developed a new life cycle model of energy consumption and greenhouse gas(GHG)emissions on China's HSR bylife cycle analysis(LCA),covering the stages of infrastructure,HSR train,and operation,based on the TLCAM(Tsinghua-LCA Model).A caseof the BeijingeShanghai HSR has been studied to show that the full life cycle energy consumption and GHG emissions of HSR transportationare 0.4 MJ km1per capita and 0.04 kg CO2ekm1per capita,respectively,which are far less than aviation,gasoline vehicles,diesel vehicles,electric vehicles and public vehicles.With the cleaner power structure and the progress of HSR train technology,the energy consumption andcarbon emissions of HSR in 2020 could be reduced by 20%compared to 2015.This study indicates that electricity generation mix structure andfull load rate are important factors influencing the life-cycle energy consumption and GHG emissions of HSR transportation.It is recommendedto improve the coverage of HSR network,accelerate train upgrades,improve the full load rate of HSR trains,and promote the low-carbondevelopment of electricity supply to strengthen and realize the low-carbon advantage of HSR transport mode in China.HSR transportationcan be used to achieve the low carbon transformation of China's transportation sector and improve oil supply safety situation.

关键词： High-speed railway transport Life cycle analysis Energy consumption Greenhouse gas emissions China

Enhancing {1012} twin boundary migration capability in Ti-Al solid solution alloys with increasing Al content

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Journal of Materials Science & Technology 2023年第16期147卷 217-223页

作者： Hao Zhang Bingqiang Wei Xiaoqin ou Song Ni Xiaozhou Liao min Song State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China School of Aerospace Mechanical&Mechatronic EngineeringThe University of SydneySydneyNSW 2006Australia

1.Introduction Titanium(Ti)and its alloys have been widely used in the aerospace,biomedical and chemical industries due to their high specific strength,low Young’s modulus,superior biocompatibility and strong corrosion resistance[1–5].While Ti alloys have high strength,they usually present relatively poor ductility and formability at room temperature[5].Therefore,their deformation behaviors and corresponding mechanisms have been the focus of attention in order to obtain better formability and mechanical properties.Forα-Ti and its alloys with hexagonal close-packed(HCP)structure,the most common slip system is prismatic a slip at room temperature[6–9].Pyramidal c+a slip can coordinate c-axis strain,but it is general difficult to activate c+a slip in polycrystalline Ti alloys[6,9]although reducing grain size can increase the propensity of c+a slip[9].Due to the limited slip systems for accommodating c-axis strain,deformation twinning plays an important role to coordinate strain along the c-axis of the HCP structure during plastic deformation.

关键词： alloys deformation corrosion

茶多酚对人乳腺癌细胞MCF-7凋亡的影响及其机制研究（英文）

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2017年第2期18卷 89-98页

作者： Shu-min LIU Shi-yi ou Hui-hua HUANG Department of Food Science and Engineering South China University of Technology Department of Food Science and Engineering Jinan University

目的:评估茶多酚对人乳腺癌细胞MCF-7凋亡的影响,并探讨了其作用机制。创新点:全面考察了茶多酚对抗乳腺癌的分子机制,为茶多酚作为抗肿瘤辅助药物提供理论依据。方法:首先选取不同组织来源的五种人肿瘤细胞(人肝癌细胞Hep G2、人肺癌细... 详细信息

目的:评估茶多酚对人乳腺癌细胞MCF-7凋亡的影响,并探讨了其作用机制。创新点:全面考察了茶多酚对抗乳腺癌的分子机制,为茶多酚作为抗肿瘤辅助药物提供理论依据。方法:首先选取不同组织来源的五种人肿瘤细胞(人肝癌细胞Hep G2、人肺癌细胞A549、人前列腺癌细胞PC3、人宫颈癌细胞Hela、人乳腺癌细胞MCF-7)作为体外模型,以MTT法检测茶多酚对其增殖抑制作用。然后,选用最敏感细胞MCF-7为研究对象,采用流式细胞术检测茶多酚对细胞周期分布的影响,用Hoechst 3328染色法观察茶多酚对细胞核形态的影响,用JC-1染色法观察茶多酚对细胞线粒体跨膜电位的影响,用双氯荧光素(DCFH-DA)染色法观察茶多酚对细胞活性氧(ROS)水平的影响,用凝胶电泳DNA片段测定法(DNA ladder)观察茶多酚处理后细胞DNA断裂情况,用蛋白质印迹法(Western blot)检测茶多酚对细胞凋亡关键蛋白caspase-3和caspase-9表达的影响,全面探讨了茶多酚体外抗肿瘤机制。结论:实验结果显示,茶多酚能够通过诱导细胞周期阻滞和线粒体凋亡抑制MCF-7细胞增殖。茶多酚诱导线粒体凋亡的途径是使线粒体跨膜电位下降,促使MCF-7细胞内ROS生成,促使细胞DNA断裂和促进细胞内caspase-3和caspase-9的活化。

关键词：茶多酚人乳腺癌细胞MCF-7 细胞凋亡细胞周期阻滞线粒体凋亡

Synthesis and characterization of macrocyclic compounds with a hydroxyl functional group

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Chinese Chemical Letters 2013年第10期24卷 869-872页

作者： Min ou Chun Zhu Qi-Long Zhang Bi-Xue Zhu Key Laboratory of Macrocyclic and Supramolecular Chemistry Guizhou University Department of Chemistry Guiyang Medical College

A novel [1＋1] Schiff-base macrocyclic compound 3 has been synthesized from precursor 1, 1,3-bis（2＇- formylphenoxy）-2-propanol, and precursor 2, resorcinol-bis（4-aminophenyl）ether, via condensation and cyclizaction using Ba2＋ as template. The macrocycle 3 was further reduced giving saturated macrocycle 4. The structures of 3 and 4 were characterized by elemental analysis, ~H NMR, IR, and MS spectra, and their structures were determined via single crystal X-ray diffraction studies. X-ray diffraction analysis revealed that the macrocyclic compound 3 has a folded conformation, and the corresponding reduced product 4 adopts a twisted and folded conformation due to its flexible nature. ~ 2013 Bi-Xue Zhu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

关键词： Schiff base Macrocyclic compound Synthesis Structure

Effect of boron addition on the microstructure and mechanical properties of K4750 nickel-based superalloy

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Journal of Materials Science & Technology 2021年第1期60卷 177-185页

作者： Xiaoxiao Li Meiqiong ou min Wang Long Zhang Yingche Ma Kui Liu Institute of Metal Research Chinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei230026China

The effect of boron addition at 0,0.007 wt.% and 0.010 wt.% on the microstructure and mechanical properties of K4750 nickel-based superalloy was studied.The microstructure of the as-cast and heat-treated alloys was analyzed by SEM,EPMA,SIMS and TEM.Lamellar M_(5) B_(3)-type borides were observed in boroncontaining as-cast alloys.After the full heat treatment,boron atoms released from the decomposition of M_(5) B_(3) borides were segregated at grain boundaries,which inhibited the growth and agglomeration of M_(23)C_(6) carbides.Therefore,the M_(23)C_(6) carbides along grain boundaries were granular in boron-containing alloys,while those were continuous in boron-free alloys.The mechanical prope rty analysis indicated that the addition of bo ron significantly improved the tensile ductility at room tempe rature and stress rupture properties at 750℃/430 MPa of K4750 alloy.The low tensile ductility at room temperature of 0 B alloy was attributed to continuous M_(23)C_(6) carbides leaded to stress concentration,which provided a favorable location for crack nucleation and propagation.The improvement of the stress rupture properties of boron-containing alloys was the result of the combination of boron segregation increased the cohesion of grain boundaries and granular M_(23)C_(6) carbides suppressed the link-up and extension of micro-cracks.

关键词： Nickel-based superalloy Boron addition Secondary ion mass spectrometry(SIMS) Grain boundary segregation Mechanical properties

Effect of grain boundary precipitates on the stress rupture properties of K4750 alloy after long-term aging at 750℃for 8000 h

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Journal of Materials Science & Technology 2021年第33期92卷 11-20页

作者： Meiqiong ou Yingche Ma Kunlei Hou min Wang Guangcai Ma Kui Liu 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

In K4750 alloy,the evolution of grain boundary(GB)precipitates,including the degradation of blocky MC carbide particles and the precipitation of granular/needle-likeηphase particles,were observed after longterm aging(LA)at 750℃for 8000 h.During MC degradation,the Ti and C released from the MC carbide combined with Ni and Cr,respectively,in theγ’matrix to formη-Ni_(3)Ti phase and Cr-rich M_(23)C_(6)carbide.Large amounts of granularηphase precipitated at GBs and the needle-likeηphase grew gradually from GBs toward the grain interior.Because of the growth of theηphase through absorbingγ’phase,γ-depleted zones were formed around theηphase.The evolution of the MC carbide andηphase was primarily responsible for the decrease of the stress rupture life and the increase of elongation.After an LA sample was tested at 750℃and 360 MPa,the residual strain distribution was investigated by electron backscatter diffraction(EBSD).The results showed that the residual strain mainly distributed at GBs,especially in the region of MC degradation and at the edges ofηphases,which was closely related to the appearance of phase interfaces.Microvoids/cracks easily initiated at phase interfaces,then easily extended along theγ-depleted zones,thus the stress rupture life of LA samples was substantially shorter than that of samples subjected to the standard treatment.In particular,because of large amounts of fine degraded MC,granular M_(23)C_(6)and granularηphase particles distributed at GBs after 750℃/8000 h LA and microvoid/crack formation could be hindered by the formation of dimples,which led to an increase of elongation.

关键词： Ni-base superalloy Long-term aging,MC carbide ηphase Stress rupture properties Residual strain distribution

Effects of temperature and alloying content on the phase transformation and{10■1}twinning in Zr during rolling

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Journal of Materials Science & Technology 2020年第6期41卷 76-80页

作者： Xinglong An Hao Zhang Song Ni Xiaoqin ou Xiaozhou Liao min Song State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China School of Aerospace Mechanical and Mechatronic EngineeringThe University of SydneySydneyNSW 2006Australia

The effects of temperature and Ti content on the deformation mechanisms of pure Zr and Zr-Ti alloys were investigated by transmission electron microscopy.The results indicate the existence of a relation between deformation-induced phase transformation from a hexagonal close-packed structure to a facecentered cubic structure and{10■1}deformation twinning.That is,when one is suppressed,the other will be promoted.The phase transformation was suppressed while the{10■1}compressive twinning was promoted with increasing the rolling temperature and/or Ti content.This can be attributed to the activation of basaldislocations at high temperature and the increased stacking fault energy with Ti content.

关键词： Zr Zr-Ti alloy Twinning Phase transformation Stacking fault energy