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Development of a New Subermerged Entry Nozzle in Thin Slab Caster

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International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 183-186页

作者： Yanping Bao Jianqiang Zhu Wei Jiang Naiyuan Tian baomei xu(Metallurgy School, University of Science & Technology Beijing, Beijing 100083, China) Metallurgy School University of Science and Technology Beijing Beijing 100083 China

The fluid flow in the mould of the thin slab continuous caster has a large intluence on the quality of slabs and its *** fluid flow pattern can be controlled by the SEN (Submerged Entry Nozzle) structure. Traditional SEN can not decrease the surface turbulence and penetration depth at the same time, especially at high casting speed. In order to improve the fluid flow in the mould, a new structure SEN-Dissipation SEN have been invented. The water modeling experiments proved that the dissipation SEN could satisfy, the needs of fluid flow condition in the mould at high casting speed.

关键词： thin slab caster mould dissipation submerged entry nozzle water-model

Fluid Flow in Tundish Due to Different Type Arrangement of Weir and Dam

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Journal of University of Science and Technology Beijing 2002年第1期9卷 13-15页

作者： Yanping Bao, Wei Jiang,baomei xu, Haizhong Zhang Metallurgy School, University of Science and Technology Beijing, Beijing 100083, China E-mail: baoyp@metall .ustb .edu. cn Metall. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Tundish is an important metallurgical reactor in the continuous castingprocess. In order to control the fluid flow in tundish and thus take full advantage of the residencetime available for the removal of inclusions from molten steel, the effect of weir and dam on thefluid flow has been studied in a water model based on the characteristic number Froude and Reynoldnumber similarity criteria. The residence time distribution curves of the flow were measured bySG800. The optimum arrangement of darn and weir and the nonstationary flow in tundish werediscussed. The results show that the combination of weir and dam is benefit for the flow pattern intundish, weir can prevent the upper recirculating flow, dam can cut off the bottom flow and turn toupwards, it is advantageous to separate the nonmetallic inclusions. Furthermore, it is important toexceed the critical depth of bath during exchange ladles, not only for the inclusion floatation butalso for avoiding tundish slag drainage earlier.

关键词： tundish fluid flow weir and dam water model

MATHEMATICAL MODELLING OF FLOW PHENOMENA IN METAL BATH COVERED WITH MOLTEN SLAG

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Acta Metallurgica Sinica(English Letters) 1990年第12期3卷 370-376页

作者： QU Ying YANG Jian xu baomei University of Science and Technology Beijing,Beijing,China

By use of the two-component LDA and high speed camera,the water model of the flow field in metal bath under molten slag layer has been *** the basis of experimental results,the flow boundary conditions of liquid metal at the slag-metal interface of a gas injecting bath were *** flow field and the turbulent parameters of the metal bath covered with slag were solved by the vorticity-stream function *** results reveal that the flow velocity, turbulent energy and circulating rate of the melt under slag are lower than that of without *** one “dead zone” of the lowest turbulent energy is formed in the top layer under cover of slag near the ladle linning.

关键词： flow field metal bath injection metallurgy mathematical modelling

Flash nanocomplexation (FNC): A new microvolume mixing method for nanomedicine formulation

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Chinese Chemical Letters 2024年第10期35卷 39-52页

作者： Keyang Li Yanan Wang Yatao xu Guohua Shi Sixian Wei xue Zhang baomei Zhang Qiang Jia Huanhua xu Liangmin Yu Jun Wu Zhiyu He Frontiers Science Center for Deep Ocean Multispheres and Earth Systems Key Laboratory of Marine Chemistry Theory and TechnologyMinistry of Education/Sanya Oceanographic InstitutionOcean University of ChinaQingdao/Sanya 266100/572024China College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266003China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Guangzhou City Polytechnic Guangzhou 510520China National Key Laboratory for the Modernization of Classical and Famous Prescriptions of Chinese Medicine Jiangxi University of Chinese MedicineNanchang330004China Division of Life Science The Hong Kong University of Science and TechnologyHong Kong SAR 999077China

The application of nanotechnologies in formulation has significantly promoted the development of modern medical and pharmacological science, especially for nanoparticle-based drug delivery, bioimaging, and theranostics. The advancement of engineering particle design and fabrication is largely supported by a better understanding of how their apparent characteristics(e.g., size and size distribution, surface morphology, colloidal stability, chemical composition) influence their in vivo biological performance, which raises an urgent need for practical nanoformulation methods. Based on turbulent flow mixing and the self-assembly of molecules in fluids, flash technologies emerged as effective bottom-up fabrication strategies for effective nanoformulation. Among the flash technology family, flash nanocomplexation(FNC) is considered a novel and promising candidate that can promote and optimize formulation processes in a precise spatiotemporal manner, thus obtaining excellent fabrication efficiency, reproducibility and expandability. This review presents an overview of recent advances in fabricating drug-delivery nanoparticles using FNC platforms. Firstly, brief introductions to the basic principles of FNC technology were carried out, followed by descriptions of turbulent microvolume mixers that have significantly promoted the efficiency of FNC-based fabrications. Applications of real formulation cases were then categorized according to the self-assembly-driven interactions(including electrostatic interaction, coordination interaction,hydrogen bonding and hydrophobic interaction) and discussed to reveal the progressiveness of fabricating nanoparticles and discuss how its flexibility will provide advances and replenish the philosophy of nanomedicine formulation. In the end, the commercial potential, current limitations, and prospects of FNC technology for nanoformulation will be summarized and discussed.

关键词： Nanoformulation Nanoparticles Self-assembly Flash nanocomplexation Kinetic control Drug delivery

Impact of bacterial chaperonin GroEL–GroES on bacteriorhodopsin folding and membrane integration

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Biophysics Reports 2019年第3期5卷 133-144页

作者： Xinwei Lu baomei xu Haiyan Sun Junting Wei Haixia Chi Naseer Ullah Khan Xiaojuan Wang Xiaoqiang Wang Fang Huang State Key Laboratory of Heavy Oil Processing College of Chemical Engineering China University of Petroleum (East China)

Our understanding of molecular chaperone function in membrane protein biogenesis lags far behind that in soluble protein biogenesis. Through a combined approach including isothermal titration calorimetry, UV–Vis spectroscopy, and fluorescence spectroscopy, the behavior of ATP-dependent chaperonin Gro EL–Gro ES, a paradigmatic chaperone of soluble protein folding, was investigated in the refolding of membrane protein bacteriorhodopsin(BR) and its membrane insertion. We found that BR bound asymmetrically to the double-ring Gro EL, with a much higher affinity when it was partially denatured. Gro EL alone showed a clear influence on BR refolding, but the presence of ATP was necessary to significantly enhance both the rate and yield of the Gro EL-mediated folding, in contrast to the adverse effect of Gro ES on the folding yield. However, synergy between ATP and Gro ES was shown to be required not only for releasing high-affinity BR species from Gro EL, but also for unfolding and rescuing the misfolded conformers complexed to Gro EL. This is consistent with the observation that maximum rate enhancement of BR refolding or assembly with the prepared inverted membrane vesicles was achieved when the complete chaperonin system was used. Our results support the iterative unfolding mechanism of Gro EL activity previously proposed for soluble proteins, whereby Gro EL might perform repeated unfolding and release of BR, thus offering additional opportunities for timely folding or membrane integration. This work provides important information on the convergence of folding of membrane and soluble proteins in light of folding pathways and the role of molecular chaperones.

关键词： Chaperonin Membrane protein Membrane reconstitution Protein folding Protein structure

Klotho蛋白在子痫前期患者胎盘外泌体中表达及其对血管内皮细胞氧化应激的影响

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吉林大学学报（医学版） 2023年第6期49卷 1528-1538页

作者：薛筱蕾胥保梅新疆医科大学第五附属医院产科新疆乌鲁木齐830011

目的:探讨Klotho在子痫前期(PE)患者来源的胎盘外泌体(Exo)中的表达,阐明其对血管内皮细胞氧化应激的影响。方法:收集40例孕产妇的临床资料,其中正常妊娠(NP)者20名,PE患者20例,设为NP组和PE组,分离2组研究对象外周血中胎盘Exo。将oe-Kl... 详细信息

目的:探讨Klotho在子痫前期(PE)患者来源的胎盘外泌体(Exo)中的表达,阐明其对血管内皮细胞氧化应激的影响。方法:收集40例孕产妇的临床资料,其中正常妊娠(NP)者20名,PE患者20例,设为NP组和PE组,分离2组研究对象外周血中胎盘Exo。将oe-Klotho和oe-NC质粒转染入人绒毛膜滋养层细胞HTR-8/SVneo中,作为oe-Klotho组和oe-NC组,收集HTR-8/SVneo细胞Exo。采用实时荧光定量PCR(RT-PCR)法和Western blotting法检测2组研究对象胎盘Exo和2组HTR-8/SVneo细胞Exo中Klotho mRNA及蛋白表达水平。取生长状态良好的人脐静脉内皮细胞(HUVECs),按Exo来源不同将HUVECs分为PE-Exo组(与PE患者胎盘Exo共培养)、NP-Exo组(与NP胎盘Exo共培养)、oe-Klotho-Exo组(与转染oe-Klotho的HTR-8/SVneo细胞Exo共培养)和oe-NC-Exo组(与转染oe-NC的HTR-8/SVneo细胞Exo共培养)。采用透射电子显微镜(TEM)观察Exo形态表现,Western blotting法检测Exo标记分子CD63、TSG101和胎盘Exo标记分子PLAP蛋白表达水平以鉴定Exo,荧光显微镜观察HUVECs对Exo的摄取情况。酶联免疫吸附试验(ELISA)法检测各组HUVECs中一氧化氮(NO)、活性氧(ROS)和丙二醛(MDA)水平及超氧化物歧化酶(SOD)活性,RT-qPCR法检测各组HUVECs中内皮型一氧化氮合酶(eNOS)mRNA表达水平,Western blotting法检测各组HUVECs中eNOS蛋白表达水平。结果:与NP组比较,PE组患者收缩压和舒张压升高(P<0.05),新生儿体质量和胎盘质量均明显降低(P<0.05或P<0.01)。TEM观察,来源于NP组和PE组研究对象的胎盘Exo均呈圆形和椭圆形的囊泡盘状结构,包膜完整,形状相似,直径为50~100 nm;2组研究对象胎盘Exo均高表达Exo标记蛋白CD63和TSG101及胎盘Exo特异性蛋白PLAP。纳米示踪分析(NTA)检测,胎盘Exo的粒径为50~200 nm,提示由外周血分离的囊泡均是胎盘来源Exo。TEM、Western blotting和NTA检测,来源于oe-NC组和oe-Klotho组滋养层细胞的囊泡具有Exo的典型结构、分子标志物和粒径大小特征。HUVECs中均可见到明显的Exo绿色荧光表达,提示Exo可被HUVECs摄取。ELISA法检测,与NP-Exo组比较,PE-Exo组HUVECs中NO水平和SOD活性均明显降低(P<0.05或P<0.01),ROS和MDA水平明显升高(P<0.05或P<0.01);与oe-NC-Exo组比较,oe-Klotho-Exo组HUVECs中NO水平和SOD活性升高(P<0.05),ROS和MDA水平明显降低(P<0.05或P<0.01)。RT-qPCR法检测,与NP组比较,PE组研究对象胎盘Exo中Klotho mRNA表达水平明显降低(P<0.01);与NP-Exo组比较,PE-Exo组HUVECs中eNOS mRNA表达水平明显降低(P<0.01);与oe-NC组比较,oe-Klotho组滋养层细胞Exo中Klotho mRNA表达水平明显升高(P<0.01);与oe-NC-Exo组比较,oe-klotho-Exo组HUVECs中eNOS mRNA表达水平明显升高(P<0.01)。Western blotting法检测,与NP组比较,PE组研究对象胎盘Exo中Klotho蛋白表达水平明显降低(P<0.01);与NP-Exo组比较,PE-Exo组HUVECs中eNOS蛋白表达水平明显降低(P<0.01);与oe-NC组比较,oe-Klotho组滋养层细胞Exo中Klotho蛋白表达水平明显升高(P<0.01);与oe-NC-Exo组比较,oe-Klotho-Exo组HUVECs中eNOS蛋白表达水平均明显升高(P<0.01)。结论:来源于PE患者的胎盘Exo可能通过抑制HUVECs中NO的产生和促进氧化应激反应以损伤内皮细胞功能,过表达Klotho的滋养层细胞Exo可减少HUVECs中NO的产生和氧化应激水平。

关键词： Klotho蛋白子痫前期外泌体血管内皮细胞氧化应激

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板坯连铸结晶器内钢液流场的三维数学模型

北京科技大学学报 2001年第2期23卷 106-110页

作者：包燕平张涛蒋伟徐保美北京科技大学冶金学院北京100083

针对板坯连铸结晶器中钢液的紊流流动特征，利用流场计算软件ｃｆｘ４．３，建立了一个三维有限差分模型，模拟了结晶器内钢液的流场和流动分布，同时应用水利学模型进行了验证．通过数值计算，研究了浸入式水口的出口倾角、浸入深度、... 详细信息

针对板坯连铸结晶器中钢液的紊流流动特征，利用流场计算软件ｃｆｘ４．３，建立了一个三维有限差分模型，模拟了结晶器内钢液的流场和流动分布，同时应用水利学模型进行了验证．通过数值计算，研究了浸入式水口的出口倾角、浸入深度、拉速等工艺参数对板坯连铸结晶器流场的影响，为优化结晶器内钢液的流场，优化浸入式水口的设计提供了理论基础．

关键词：浸入式水口流场数值模拟板坯边铸结晶器钢液紊流流动三维有限差分模型