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Journal of Materials Science & Technology 2022年第11期106卷 183-194页

作者： Weili Ren Tao Zhou xiaotan yuan Ming Jian Congjiang Zhang Biao Ding Jianchao Peng Tianxiang Zheng Yunbo Zhong State Key Laboratory of Advanced Special Steel College of Materials Science and EngineeringShanghai UniversityShanghai 200444China China National South Aviation Industry Co. LtdZhuzhou 412000China Laboratory for Microstructures Shanghai UniversityShanghai 200444China

The stray crystal in the platform region is one of the common main defects in single-crystal superalloy blades. The simple and effective method to eliminate this defect is urgent to be explored. This work found that the Cusp magnetic field can effectively inhibit the stray-crystal formation in the platform. The tendency of stray-crystal formation decreases as the magnetic-field strength increases at a certain withdrawal rate and temperature-gradient. The suppressing effect decreases as the withdrawal rate or the temperature-gradient increases. Finally, the inhibiting mechanism on the stray-crystal formation from the Cusp magnetic field is proposed based on the experiments and the numerical simulation. The magneticfield application strengthens the flow velocity and changes the flow structure near the liquid-solid interface, and further reduces the radial temperature difference. Accordingly, the secondary dendrites in the heat-conduction undercooled zone expands towards the corner in a faster speed, which reduces the stray-crystal formation in the platform corner. This study provides an effective and simple method for decreasing the stray-crystal formation during the preparation of single-crystal with platform region.

关键词： Single-crystal superalloy Cusp magnetic field Stray crystals Platform region

Effects of longitudinal magnetic field on primary dendrite spacing and segregation of directionally solidified single crystal superalloy

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Progress in Natural Science:Materials International 2024年第1期34卷 26-36页

作者： Congjiang Zhang Yilin Zhou Chen Shen Weili Ren xiaotan yuan Biao Ding Haibiao Lu Zuosheng Lei Yunbo Zhong Ang Zhang State Key Laboratory of Advanced Special Steel College of Materials Science and Engineering Shanghai University National Engineering Research Center for Magnesium Alloys Natural Key Laboratory of Advanced Casting Technologies College of Materials Science and EngineeringChongqing University

The primary dendrite spacing(PDS) and segregation of directionally solidified single crystal(SC) superalloy under the longitudinal magnetic field(LMF) were investigated based on the analysis of the whole cross-sectional microstructure at different solidification distances. The results show that the PDS under the LMF remains basically unchanged at different solidification distances, and it is greater than that under no LMF. With the increase of magnetic field intensity, the PDS increases and the macrosegregation decreases. The increasing PDS and reducing segregation under the LMF can be attributed to the increase of solute boundary layer, which expands the non-equilibrium freezing temperature range and brings the effective partition coefficient closer to 1. The increase of the solute enrichment layer thickness could be caused by the downward secondary circulation generated by the thermoelectric magnetic convection(TEMC) near the interface, which drives the migration of solutes towards the interdendritic region. This work not only clarifies the mechanism of LMF controlling PDS and reducing segregation by TEMC, but also provides theoretical guidance for producing high-quality SC superalloys using magnetic fields.

关键词： Primary dendrite spacing Segregation Single crystal superalloy Directional solidification Magnetic field Thermoelectric magnetic convection

Nondestructive effect of the cusp magnetic field on the dendritic microstructure during the directional solidification of Nickel-based single crystal superalloy

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Journal of Materials Science & Technology 2021年第3期62卷 52-59页

作者： xiaotan yuan Tao Zhou Weili Ren Jianchao Peng Tianxiang Zheng Long Hou Jianbo Yu Zhongming Ren Peter K.Liaw Yunbo Zhong State Key Laboratory of Advanced Special Steel College of Materials Science and EngineeringShanghai UniversityShanghai 200444China Laboratory for Microstructures Shanghai UniversityShanghai 200444China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996USA

The mechanical-property improvement of directionally-solidified Nickel-based single crystal(SC)superalloy with the single-direction magnetic fields is limited by their destructiveness on the dendritic ***,the work present breaks through the *** shows that the application of the cusp magnetic field(CMF)ensures that the dendrites are not *** feature embodies that the primary dendrite trunks arrange regularly and orderly,as well the secondary dendrite arms grow *** contrast,both the unidirectional transverse and longitudinal magnetic field destroy the dendrite morphology,and there are a number of stray grains near the totally-re melted *** nondestructive effect is achieved mainly by the combined action of the thermoelectromagnetic force on the dendrites and thermoelectromagnetic convection in the melt during directional *** investigation should contribute a new route for dramatically and effectively improving the crystal quality and mechanical properties of the directionally-solidified alloys.

关键词： Dendrites Single-crystal superalloy Magnetic fields Directional solidification

Effect of Magnetic Field Configuration on Stray-Crystal Formation with Different Platform Sizes during Directional Solidification of Single-Crystal Superalloy

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 904-914页

作者： Keke Lu Congjiang Zhang xiaotan yuan Hongbin Yu Weili Ren Biao Ding Haibiao Lu Yunbo Zhong Zuosheng Lei Hui Wang Qiuliang Wang Peter KLiaw Xuezhi Qin Lanzhang Zhou State Key Laboratory of Advanced Special Steel Shanghai Key Laboratory of Advanced FerrometallurgyShanghai UniversityShanghai 200444China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996USA Institute of Metal Research Chinese Academy of SciencesShenyang 110016China

The magnetic field is an effective means to control the solidification structure and the defects of metal and semiconductor *** work investigates the effects of Cusp magnetic field(CMF)and longitudinal magnetic field(LMF)on the stray-crystal formation in the platform regions during the directional solidification of single-crystal superalloy with the different cross section *** application of CMF reduces the formation of platform stray-crystal,while LMF increases its *** the platform size increases,the stray-crystal ratio increases regardless of whether the magnetic fields are applied or not,the effectiveness of CMF increases,while that of LMF *** reason that the effects of CMF and LMF on the platform stray-crystal formation could be attributed to the change of flow structure from the distribution characteristics of the thermoelectric magnetic force and the magnetic damping force near the liquid-solid interface.

关键词： Stray-crystal Magnetic field Single-crystal superalloy Cross section change Directional solidification

Saponins Content in Fibrous Roots of Pseudostellaria heterophylla and Optimization of the SEP Extraction Technology

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Medicinal Plant 2020年第4期11卷 60-63页

作者： Yanda ZHANG Huiqing PAN Yufang MA xiaotan yuan Hegui LIN Qi ZHAO Municipal Enterprise Technical Center of Fujian Beidi Pharmaceutical Co. Ltd. Ningde 355300 China College of Animal Sciences Fujian Agricultural and Forestry University Fuzhou 350002 China Pharmaceutical Development Center of Zherong County Ningde 355300 China

[Objectives]To explore the saponins resources in fibrous roots of Pseudostellaria heterophylla and optimize the SEP technology for extracting saponins.[Methods]Saponins contents in fibrous roots and root tubers of *** were compared;with the fibrous roots as host materials,this experiment applied Box-Behnken design to analyze the influence of steam pressure,maintenance pressure time,moisture content of host materials on the content of saponins extracts.[Results]Saponins content was higher in fibrous roots than in tuberous roots of ***;the response surface optimization showed that SEP(steam explosion pretreatment)promoted the contents of saponins and extracts in fibrous roots,and the optimal extracting conditions were stream pressure 1.50 Mpa,maintenance pressure time 54 s,and moisture content of host materials 30%.Under this extracting conditions,the verification value of saponins content experiment was 0.441%,36.53%higher than the untreated control group.[Conclusions]This research offered a new method of exploring saponins resources from fibrous roots of ***,and provided a reference for developing new medicinal parts of ***.

关键词： Fibrous root Pseudostellaria heterophylla Saponin Extraction technology Response surface optimization

不同发育期小鼠卵巢组织中Wnt5a蛋白表达水平及其对卵母细胞自噬的影响

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吉林大学学报（医学版） 2022年第2期48卷 277-283页

作者：马亚博原筱潭谢贤国刘新峰徐金瑞杨易宁夏大学西部特色生物资源保护与利用教育部重点实验室宁夏银川750021 宁夏大学生命科学学院微生物与分子生物学系宁夏银川750021

目的:探讨不同发育期小鼠卵巢组织中Wnt5a蛋白表达水平,并阐明Wnt5a对卵母细胞自噬的影响。方法:收集不同发育期小鼠卵巢组织,采用Western blotting法检测Wnt5a蛋白在小鼠围产期卵巢组织中的表达水平,选取新生1 d(1 dpp)小鼠卵巢组织进... 详细信息

目的:探讨不同发育期小鼠卵巢组织中Wnt5a蛋白表达水平,并阐明Wnt5a对卵母细胞自噬的影响。方法:收集不同发育期小鼠卵巢组织,采用Western blotting法检测Wnt5a蛋白在小鼠围产期卵巢组织中的表达水平,选取新生1 d(1 dpp)小鼠卵巢组织进行免疫荧光染色,将卵母细胞胞质标记物DDX4和颗粒细胞标记物FOXL2(红色)分别与Wnt5a(绿色)和细胞核标记物Hoechst(蓝色)共染后,观察卵母细胞形态和数量。体外培养胚胎期17.5 d(17.5 dpc)小鼠卵巢组织,分为对照组、1 mol·L^(-1)过表达Wnt5a组(rWnt5a组)、1 mol·L^(-1)抑制剂IWP2组和1 mol·L^(-1)抑制剂BOX5组,采用Western blotting法检测各组小鼠卵巢组织中Wnt5a、微管相关蛋白1轻链3(LC3)和P62蛋白表达水平,免疫荧光法观察卵巢卵母细胞数量。结果:Wnt5a在不同发育阶段小鼠卵巢组织中均有表达,与13.5 dpc组比较,17.5 dpc和1 dpp组Wnt5a蛋白表达水平均明显升高(P<0.05),荧光定位发现目的蛋白Wnt5a与标记物DDX4和FOXL2有重叠部分。Western blotting法检测,与对照组比较,rWnt5a组Wnt5a蛋白表达水平明显升高(P<0.01),抑制剂IWP2组Wnt5a和LC3蛋白表达水平明显降低(P<0.01),抑制剂BOX5组Wnt5a蛋白表达水平明显升高(P<0.01);与rWnt5a组比较,抑制剂IWP2组LC3蛋白表达水平明显降低(P<0.01),P62蛋白表达水平明显升高(P<0.01)。免疫荧光染色,与对照组比较,抑制剂IWP2组卵巢中卵母细胞数目减少。结论:Wnt5a可能通过影响小鼠卵巢内自噬水平调控卵母细胞的存活。

关键词： Wnt5a 卵巢组织卵母细胞颗粒细胞自噬

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Wnt5a激活c-Jun氨基末端激酶(JNK)促进KGN人颗粒细胞增殖和自噬

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细胞与分子免疫学杂志 2022年第11期38卷 992-997页

作者：马亚博谢贤国原筱潭刘新峰徐金瑞杨易宁夏大学西部特色生物资源保护与利用教育部重点实验室宁夏银川750021 宁夏大学生命科学学院微生物与分子生物学系宁夏银川750021

目的探究无翅基因5a(Wnt5a)对KGN人颗粒细胞自噬的作用。方法采用Wnt5a重组蛋白(rWnt5a)、抑制剂IWP2和BOX5处理KGN人颗粒细胞并设置对照组,Western blot法检测Wnt5a蛋白表达水平,免疫荧光细胞化学染色法观察rWnt5a组和抑制剂IWP2组中... 详细信息

目的探究无翅基因5a(Wnt5a)对KGN人颗粒细胞自噬的作用。方法采用Wnt5a重组蛋白(rWnt5a)、抑制剂IWP2和BOX5处理KGN人颗粒细胞并设置对照组,Western blot法检测Wnt5a蛋白表达水平,免疫荧光细胞化学染色法观察rWnt5a组和抑制剂IWP2组中Wnt5a蛋白和颗粒细胞特异性标志物叉头盒L2(FOXL2)的表达共定位。CCK-8法检测KGN细胞的增殖能力,Western blot法检测rWnt5a及其抑制剂IWP2对KGN细胞自噬的影响以及c-Jun氨基末端激酶(JNK)和活化T细胞核因子1(NFAT1)蛋白的表达变化。结果与对照组相比,rWnt5a组Wnt5a蛋白水平增加,促进细胞增殖,微管相关蛋白1轻链3(LC3)、 JNK、 NFAT1蛋白表达增加,核孔蛋白62(P62)蛋白表达降低;IWP2组Wnt5a蛋白水平降低,抑制人颗粒细胞增殖,LC3、 JNK和NFAT1蛋白表达降低,P62表达增加。结论 Wnt5a激活JNK促进KGN人颗粒细胞的增殖和自噬。

关键词：无翅基因5a(Wnt5a) KGN人颗粒细胞细胞自噬细胞增殖

纵向静磁场下单晶高温合金定向凝固籽晶回熔界面杂晶的形成与演化

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金属学报 2023年第12期59卷 1568-1580页

作者：苏震奇张丛江袁笑坦胡兴金芦可可任维丽丁彪郑天祥沈喆钟云波王晖王秋良上海大学材料科学与工程学院上海200444 上海大学省部共建高品质特殊钢冶金与制备国家重点实验室上海200444 中国科学院电工研究所北京100190

通过对单晶高温合金定向凝固生长过程中显微组织的考察,研究了磁场下杂晶在籽晶回熔区附近的产生及其在生长过程中的演变机制。磁场使得定向凝固籽晶重熔区界面上出现大取向杂晶和大角度晶界,其多分布于样品边缘,磁场强度和抽拉速率的... 详细信息

通过对单晶高温合金定向凝固生长过程中显微组织的考察,研究了磁场下杂晶在籽晶回熔区附近的产生及其在生长过程中的演变机制。磁场使得定向凝固籽晶重熔区界面上出现大取向杂晶和大角度晶界,其多分布于样品边缘,磁场强度和抽拉速率的增大均增加了杂晶数量和大角度晶界长度。凝固起始阶段形成的大取向杂晶和大角度晶界以较快速率被淘汰,演化成小取向枝晶和小角度晶界;随着凝固继续进行,枝晶取向和晶界角度进一步减小,但是演化速率急剧降低,拉速的增大强化了此演变过程。重熔区界面上杂晶的形成是由于热电磁力对枝晶的扭断,而宏观尺度上的热电磁环流在凝固过程挟制着扭断碎晶,使得碎晶演化成较多分布于样品边缘的杂晶。

关键词：单晶高温合金纵向静磁场定向凝固杂晶

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Wnt信号通路在卵泡发育中的调控研究

宁夏大学学报（自然科学版） 2021年第2期42卷 192-196页

作者：马亚博吴霜马慧原筱潭侯海蓝田徐金瑞杨易宁夏大学生命科学学院宁夏银川750021

卵巢是维系女性生育的重要器官,主要功能是产生卵子,完成人类繁殖的任务.卵泡作为卵母细胞发生和发育的基本功能单位,控制着雌性哺乳动物所有的生殖活动.近几年的研究显示,Wnt信号通路在调节卵巢卵泡发育和类固醇生成等方面发挥重要作用... 详细信息

卵巢是维系女性生育的重要器官,主要功能是产生卵子,完成人类繁殖的任务.卵泡作为卵母细胞发生和发育的基本功能单位,控制着雌性哺乳动物所有的生殖活动.近几年的研究显示,Wnt信号通路在调节卵巢卵泡发育和类固醇生成等方面发挥重要作用,在卵巢早衰、卵巢癌等女性生殖疾病中起到重要调控作用.就Wnt信号通路对卵泡发育的影响及其作用机制做详细综述.

关键词： Wnt信号通路卵泡发育卵巢

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胎儿动静脉畸形的产前超声诊断研究

中国全科医学 2022年第29期25卷 3691-3697页

作者：谭筱檀袁红霞湖南省长沙市妇幼保健院超声科 410007

背景胎儿动静脉畸形可发生在全身各个部位,主要依靠彩色多普勒超声进行诊断,而关于产前超声诊断动静脉畸形类型的探讨国内外鲜有报道。目的探讨产前超声诊断胎儿动静脉畸形的价值。方法选取2013年8月至2021年8月在长沙市妇幼保健院超声... 详细信息

背景胎儿动静脉畸形可发生在全身各个部位,主要依靠彩色多普勒超声进行诊断,而关于产前超声诊断动静脉畸形类型的探讨国内外鲜有报道。目的探讨产前超声诊断胎儿动静脉畸形的价值。方法选取2013年8月至2021年8月在长沙市妇幼保健院超声科行产前超声筛查胎儿动静脉畸形的孕妇为研究对象,采用彩色多普勒超声诊断仪进行胎儿系统超声筛查,发现胎儿动静脉畸形病灶时,描述其位置、大小、形态、内部回声。分析不同部位动静脉畸形的超声特征及动静脉畸形分型,并追踪随访结果。结果本研究中产前超声筛查发现胎儿动静脉畸形病例16例,其中6例病灶位于胎儿骶尾部(诊断为骶尾部畸胎瘤),4例位于胎儿颅内(包括3例颅内蔓状血管瘤合并Galen静脉瘤、1例Galen静脉瘤),3例位于胎儿肢体、软组织(包括1例Parkes-Weber综合征、2例软组织血管瘤),2例位于胎儿肝脏(诊断为肝动静脉瘘),1例位于胎儿肺部(诊断为隔离肺并肺动静脉瘘)。动静脉畸形分型:单纯Ⅱ型10例(10/16),Ⅱ型和Ⅲa型同时存在3例(3/16),单纯Ⅰ型1例(1/16),单纯Ⅳ型1例(1/16),单纯Ⅲa型1例(1/16)。随访显示,10例引产,3例失访,2例足月出生后行手术治疗,1例死胎。结论胎儿动静脉畸形的预后与病变部位、病灶内血流分布情况关系密切。产前超声检查可发现胎儿有无动静脉畸形病灶,对其诊断、预后判断具有重要价值。

关键词：动静脉畸形产前诊断超声检查,产前胎儿超声检查,多普勒,彩色