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Micro Extrusion of Ultrafine Grained Titanium Prepared by ECAP

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Journal of Wuhan University of Technology(Materials Science) 2017年第2期32卷 437-443页

作者：王效岗 LIU Jianlong zhao xicheng LIU Xiaoyan XIE Haibo JIANG Zhengyi Shanxi Province Metallurgical Equipment Design Theory and Technology Key Laboratory (Provincial Department to Build National Key Laboratory Training Base) Taiyuan University of Science and Technology Taiyuan 030024 China Metallurgical Engineering College Xi'an University of Architecture and Technology Xi'an 710055 China School of Mechanical Materials and Mechatronic Engineering University of Wollongong Wollongong NSW 2522 Australia

Micro compression and micro extrusion experiments of ultrafine grained titanium cylindrical specimens in diameters of 4, 2, and 1 mm prepared by equal channel angular pressing（ECAP） were conducted on the micro plastic forming test machine. The effects of specimen size, grain size, deformation temperature and extrusion speed on the flow stress and forming properties of the ultrafine grained pure titanium were investigated. The flow stress of ultrafine grained pure titanium specimen decreases with decreasing specimen size. The yield limit of pure titanium with refined grain prepared by ECAP is significantly greater than that of coarse grained specimen. Also the research results show that the flow stress of specimen increases with decreasing deformation temperature and with the increase of the strain rate, and the ultrafine grained pure titanium possesses good micro forming properties at deformation temperature of 300 ℃.

关键词： micro forming ECAP pure titanium flow stress micro extrusion

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大跨径单箱双室连续梁桥0号块空间受力分析

黑龙江交通科技 2024年第5期47卷 76-80页

作者：赵希成王青云李明阳长沙理工大学湖南长沙410114 中铁大桥局第九工程有限公司广东中山528400 佛山市交通科技有限公司广东佛山528300

以佛山南沙涌特大桥为工程实例,对施工阶段过程中不利工况以及长期运营阶段中的墩顶最不利弯矩和剪力组合应力状况进行分析,得出单箱双室0号块在三向预应力情况下的应力结果和分布规律。结果表明最大单悬臂施工阶段、成桥阶段无活载以... 详细信息

以佛山南沙涌特大桥为工程实例,对施工阶段过程中不利工况以及长期运营阶段中的墩顶最不利弯矩和剪力组合应力状况进行分析,得出单箱双室0号块在三向预应力情况下的应力结果和分布规律。结果表明最大单悬臂施工阶段、成桥阶段无活载以及成桥后长期荷载作用下,支座附近、顶底板与腹板连接处、横隔板与顶板连接处产生较大的拉应力,且单箱双室的顶板的倒角汇合区域产生了集中拉应力。建议在单箱双室的设计中适当加厚顶板,施工中注意顶板压浆密实性。

关键词：预应力混凝土连续梁桥单箱双室 0号块空间应力

Morphology and Molecular Identification of Root-knot Nematode in Partial Tobacco-growing Areas in Yunnan Province

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Plant Diseases and Pests 2017年第2期8卷 13-19页

作者： Yang Yanmei Liang Yan Yuan Shaojie zhao xicheng Hu Xianqi State Key Laboratory for Conservation and Utilization of Bio-Resources Yunnan Agriculture University

[Objectives]The species and distribution of root-knot nematodes in tobacco growing regions of Yunnan were investigated,in order to provide reference for comprehensive prevention of root-knot nematodes disease and tobacco variety layout. [Methods]Fifty-four samples of root-knot nematode host on tobacco crops were collected from Kunming,Qujing and Yuxi cities in Yunnan from August to October in 2015. The species of root-knot nematodes were identified by observing perineal patterns and molecular biological testing（ PCR of ribosomal DNA of ITS region and sequence characterized amplified region,SCAR）. [Results] There were 24 samples belonging to Meloidogyne arenaria,accounting for 44. 44%; seven M. incognita samples,accounting for 12. 96%; one M. javanica sample,accounting for 1. 85%. Eleven samples were compound populations of M. javanica and M. arenaria,accounting for 20. 37%. Five were compound populations of M. incognita and M. arenaria,accounting for 9. 26%. Three were compound populations of M. incognita and M. javanica,accounting for 5. 56%. Three belonged to compound population of M. incognita,M. javanica and M. arenaria,accounting for 5. 56%. [Conclusions] The species of root-knot nematodes in tobacco growing areas of Yunnan mainly include M. incognita,M. javanica and M. arenaria. M. arenaria is the dominant population.

关键词： Tobacco Root-knot nematode Species Yunnan

Hydrothermal synthesis and luminescent properties of BaMoO_4:Sm^(3+) red phosphor

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Journal of Rare Earths 2016年第2期34卷 143-147页

作者：李兆王永锋曹静江元汝赵西成孟志新 School of Materials Engineering Xi’an Aeronautical University School of Science Xi’an University of Architecture and Technology College of Metallurgical Engineering Xi’an University of Architecture and Technology

Trivalent samarium doped barium molybdate (BaMoO4:Sm3+) red phosphor was successfully synthesized by hydrothermal method. The crystal structure, morphology and photoluminescent property were characterized by X-ray diffraction, field environ-mental scanning electron microscopy and photoluminescence spectroscopy. The results indicated that the synthesized BaMoO4:Sm3+ phosphor consisted of a pure phase with an octahedral structure. The main excitation peaks were located at 362, 404, 445 and 477 nm, respectively, and were obviously observed. The main emission peaks were located at 533, 566, 602 and 646 nm, respectively. The phosphors exhibited a red performance at 646 nm, which was appropriate for the ultraviolet-light emitting diode (UV-LED) and blue LED. The luminescent intensity of BaMoO4:Sm3+ increased with an increase in the doping amount of Sm3+. The luminescent intensity had the optimal value forx=0.03. When the doping amount of Sm3+ was further increased, the concentration quenching phenomenon was observed. Monovalent lithium (Li+) cation was used as a charge compensator. The luminescence intensity first increased with in-creasing Li+ doping concentration, and then decreased. The optimal content of Li+ was about 2%. The BaMoO4:Sm3+ phosphor pre-pared in this study could act as superior red phosphor for white LEDs.

关键词： photoluminescence BaMoO4:Sm3+ concentration quenching charge compensation rare earths

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退火工艺对ECAP工业纯钛显微硬度的影响

金属热处理 2016年第9期41卷 145-148页

作者：王海赵西成西安赛特思迈钛业有限公司陕西西安710016 西安建筑科技大学冶金工程学院陕西西安710055

对TA2工业纯钛进行2道次等径弯曲通道变形(ECAP),对变形后试样进行不同温度及不同保温时间的退火,并分别测量了显微硬度,并分析了400℃退火1、2、4、8 h试样横截面的显微硬度分布。结果表明:经过ECAP变形后,材料硬度增加显著;退火后,随... 详细信息

对TA2工业纯钛进行2道次等径弯曲通道变形(ECAP),对变形后试样进行不同温度及不同保温时间的退火,并分别测量了显微硬度,并分析了400℃退火1、2、4、8 h试样横截面的显微硬度分布。结果表明:经过ECAP变形后,材料硬度增加显著;退火后,随着退火温度的升高,硬度逐渐降低;保温时间越长,硬度缓慢降低;600℃退火8 h后试样的硬度为1592 MPa,与初始工业纯钛硬度基本相同。另外,随着保温时间的增加,试样横截面硬度分布趋于均匀。

关键词：等径弯曲通道变形退火显微硬度工业纯钛

白光LED用球形钼酸钙粉体的控制合成及特性(英文)

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硅酸盐学报 2014年第10期42卷 1279-1286页

作者：李兆赵西成江元汝赵亚娟西安建筑科技大学材料与矿资学院西安710055

以去离子水和无水乙醇的混合溶液为溶剂,采用水热法成功合成出白光LED用球形CaMoO4基质粉体,制备了Eu3+、Sm3+、Pr3+掺杂的CaMoO4红色荧光材料。对CaMoO4∶Re3+(Re=Eu,Sm,Pr)荧光粉的物相、微观形貌和发光性能进行表征。结果表明:180℃... 详细信息

以去离子水和无水乙醇的混合溶液为溶剂,采用水热法成功合成出白光LED用球形CaMoO4基质粉体,制备了Eu3+、Sm3+、Pr3+掺杂的CaMoO4红色荧光材料。对CaMoO4∶Re3+(Re=Eu,Sm,Pr)荧光粉的物相、微观形貌和发光性能进行表征。结果表明:180℃水热反应24h,水与乙醇体积比为3∶1,pH=7.0时可控制合成出规则球形CaMoO4粉体。CaMoO4∶Eu3+粉体在395nm紫外光和465nm蓝光激发下,最强的红光发射峰位于618nm处,对应于Eu3+的5 D0→7 F2跃迁。CaMoO4∶Sm3+荧光粉激发峰为406和480nm,最强的红光发射峰位于649nm处,对应于Sm3+的4 G5/2→6 H9/2跃迁。CaMoO4∶Pr3+在453nm蓝光激发下,其最强红光发射峰位于655nm处,对应于Pr3+的3 P0→3 F2跃迁。而掺杂作为电荷补偿剂的碱金属Li+,可以有效提高CaMoO4∶Re3+(Re=Eu,Sm,Pr)荧光粉的发射强度。由此可知,CaMoO4∶Re3+(Re=Eu,Sm,Pr)有望成为白光LED用红色荧光粉。

关键词：钼酸钙白光发光二极管光致发光水热合成

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浅谈两套起升高度限制器的合理性设置

中国特种设备安全 2023年第1期39卷 79-83页

作者：赵西城李培峨烟台市特种设备检验研究院烟台265508

本文侧重介绍了常见的几种起升高度限制器的电气控制方面的工作原理,通过加装第二套高度限制器,对以不同形式接入起重机主回路或控制回路中实现位置限制的安全装置进行了分析,指出了在起升回路中串入第二套限位的常闭触点接入方式存在... 详细信息

本文侧重介绍了常见的几种起升高度限制器的电气控制方面的工作原理,通过加装第二套高度限制器,对以不同形式接入起重机主回路或控制回路中实现位置限制的安全装置进行了分析,指出了在起升回路中串入第二套限位的常闭触点接入方式存在的缺陷和隐患,并提出了优化接入方式,解决了第一套位置限制器失效不易发现和消除的隐患,从本质上消除了因起升高度限制器失效带来的风险。

关键词：起重机械高度位置限制器设置

工业纯钛在120°模具中的多道次ECAP室温变形组织与性能(英文)

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稀有金属材料与工程 2009年第6期38卷 955-957页

作者：杨西荣赵西成付文杰西安建筑科技大学陕西西安710055

在室温,采用通道夹角为120°的变形模具对工业纯钛(Commercial Pure Titanium,CP-Ti)以Bc方式实施四道次ECAP(Equal Channel Angular Pressing)挤压变形,成功获得表面光滑无裂纹的变形试样。文中主要研究了工业纯钛在室温下进行ECAP多... 详细信息

在室温,采用通道夹角为120°的变形模具对工业纯钛(Commercial Pure Titanium,CP-Ti)以Bc方式实施四道次ECAP(Equal Channel Angular Pressing)挤压变形,成功获得表面光滑无裂纹的变形试样。文中主要研究了工业纯钛在室温下进行ECAP多道次变形的组织结构演变,并测试了变形试样的力学性能。微观结构显示工业纯钛在室温下进行多道次ECAP变形时,只在前两道次产生了大量的变形孪晶,且随道次增加变形孪晶逐渐消失。最终获得的试样晶粒平均尺寸由最初的约28μm细化到约250nm,试样断裂强度和显微硬度分别提高到773和2486MPa,而试样仍保持较好的延伸率(可达16.8%)。

关键词：等径弯曲通道变形(ECAP) 工业纯钛(CP-Ti) 组织结构机械性能

热轧温度的控制对B550L钢组织性能的影响

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热加工工艺 2011年第2期40卷 4-7页

作者：马占福赵西成西安建筑科技大学冶金工程学院陕西西安710055

通过对加热温度、终轧温度、冷却速度及卷取温度的控制,结合对实验样品进行组织、金相分析,研究温度对B550L钢在轧制过程中组织性能的影响。实验结果确定了最佳的工艺制度方案,加热温度为(1180±20)℃;终轧温度为(870±20)℃;精轧总变... 详细信息

通过对加热温度、终轧温度、冷却速度及卷取温度的控制,结合对实验样品进行组织、金相分析,研究温度对B550L钢在轧制过程中组织性能的影响。实验结果确定了最佳的工艺制度方案,加热温度为(1180±20)℃;终轧温度为(870±20)℃;精轧总变形量为82.35%;冷却速率控制在(10±2)℃/s;卷取温度控制在(570±20)℃。

关键词：温度制度抗拉强度延伸晶粒