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Tribological properties of TiAlN-coated cermets

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Rare Metals 2009年第1期28卷 57-62页

作者： zheng liyun ZHAO Lixin XIONG Weihao Key Laboratory of Resource Explore Research of Hebei Province Hebei University of Engineering Handan 056038 China College of Materials Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

Ti（C,N）-based cermets were coated with TiAlN using multi-arc ion plating technology. Sliding wear tests were performed on the coated cermets. The microstructure and morphologies of the coated cermets before and after friction and wear tests were characterized. The results show that the TiAlN coating surface was smooth and its root mean square roughness was 16.6 nm. The hardness （HK） of TiAlN coating layers reached approximately 3200 and the critical load （Lc） under which the coating failure occurred was 59 N. The sliding wear test results show that the friction coefficients of the TiAlN-coated cermets were lower than that of the cermets without any coating. Under the same load, the adhesion phenomenon of the counterpart materials on the specimens was improved and the mean friction coefficient increased with increasing sliding velocity. When the sliding velocity was 0.26 m·s^-1, the mass of the coated cermets reduced. At the same sliding velocity, the average friction coefficient of the TiAlN-coated cerrnets was lower under a higher load. The wear mechanisms of the TiAlN-coated cermets were mainly adhesive and abrasive wear.

关键词： cermets tribological properties wear TiAIN coating

Microstructure and mechanical properties of hot isostatically pressed cermets with TiN coatings

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Rare Metals 2006年第6期25卷 643-648页

作者： zheng liyun XIONG Weihao YAN Xianmei LI Guo＇an State Key Laboratory of Die ＆ Mould Technology Huazhong University of Science and Technology Wuhan 430074 China School of Electromechanical Engineering Hebei University of Engineering Handan 056038 China

To increase the adhesion strength between the coating and the substrate, sintered Ti（C,N）-based cermets were selected and deposited with monolayer TiN using a multiarc ion-plating technique; subsequently, hot isostatic pressing （HIPhag） treatment was performed at 1000℃ using nitrogen pressure up to 110 MPa. The mechanical properties of cermets after a coating process and subsequent HIPing treatment have been evaluated with respect to the hardness, the residual stress, and the coating adhesion. The results show that atter the HIPing process, there was a higher increase ha critical load ha the TiN-coated cermets with lower surface roughness compared with those with higher surface roughness. In all cases, the residual stress was found to be compressive. The effects of substrate surface roughness and posttreatment on the adhesion strength of the coatings were thus investigated. It was also fotmd that the HIPing posttreatment process is well suited for hacreasing the adhesion strength between the coating and the substrate.

关键词： materials surface and interface coating adhesion hot isostatic pressing cermets

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进食障碍患者临床表现的性别差异分析

中华精神科杂志 2024年第10期57卷 669-677页

作者：郑理匀陈超张大荣李雪霓孔庆梅司天梅北京大学第六医院北京大学精神卫生研究所国家精神心理疾病临床医学研究中心(北京大学第六医院)国家卫生健康委员会精神卫生学重点实验室(北京大学) 北京

目的探究进食障碍患者体重指数、进食相关行为及心理特征等方面的性别差异。方法纳入2008年8月至2015年11月就诊于北京大学第六医院的986例进食障碍患者, 其中男54例, 女932例。采用进食障碍问卷(Eating Disorder Questionnaire, EDQ)... 详细信息

目的探究进食障碍患者体重指数、进食相关行为及心理特征等方面的性别差异。方法纳入2008年8月至2015年11月就诊于北京大学第六医院的986例进食障碍患者, 其中男54例, 女932例。采用进食障碍问卷(Eating Disorder Questionnaire, EDQ)及进食障碍调查量表-1(Eating Disorder Inventory-1, EDI-1)进行进食障碍相关临床表现的横断面调查。使用1∶4的倾向性评分匹配消除年龄及诊断亚型对进食障碍患者症状表现的潜在影响。采用t检验、秩和检验、卡方检验比较男女进食障碍患者EDQ项目数据和EDI-1评分差异。使用多重线性回归进一步验证症状的性别差异。通过网络分析进食障碍患者最为重要的症状并进行性别间的比较。结果 (1)匹配后男女患者分别为54例和213例, 两者在年龄(t=-0.02)及诊断亚型构成(χ2=0.28)方面差异无统计学意义(均P>0.05)。(2)男女进食障碍患者期望体重指数与目前体重指数的差值差异有统计学意义[1.3(-0.6, 3.2)kg/m2 与-0.3(-2.3, 2.4)kg/m2;Z=-2.64, P<0.01], 男性患者期望体重高于目前体重, 女性患者期望体重低于目前体重。(3)男性进食障碍患者选择减少主食作为节食方式的比例较女性患者小[41.5%(17/41)与 63.2%(117/185);χ2=6.60, P=0.010]。(4)男性进食障碍患者对瘦的追求和内省因子分均低于女性患者(Z=-3.19、-2.26, 均P<0.05)。(5)在控制一般资料以及其他因子分后, 性别对对瘦的追求因子分影响有统计学意义(β=3.10, P<0.001)。(6)网络分析显示, 男女进食障碍患者的核心节点均为内省和对瘦的追求, 与总体进食障碍群体一致。结论男性进食障碍患者的瘦身动机弱于女性, 在症状网络中其最重要的症状为内省和对瘦的追求, 这可能与女性相似。

关键词：进食障碍性别差异体重指数行为症状心理特征网络分析

Corrosion behavior of pure zinc and its alloy under thin electrolyte layer

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Acta Metallurgica Sinica(English Letters) 2010年第6期23卷 416-430页

作者： liyun zheng Fahe CAO Wenjuan LIU Bingli JIA Jianqing ZHANG Department of Chemistry Zhe.jiang University Hangzhou 310027 China State Key Laboratory for Corrosion and Protection Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

The corrosion behavior of zinc and its alloy under thin electrolyte layers （TEL） in 0.1M NaC1 solution was investigated by cathodic polarization curves and EIS. There was only one phase in pure zinc while zinc alloy consisted of eutectic phase and primary phase. Corrosion rate of zinc alloy was faster than that of pure zinc due to the effect of the micro-galvanic couples between the primary phase and the eutectic phase. The results indicated that corrosion rate of zinc alloy was greatly enhanced under TEL than that in bulk solution. Pure zinc exhibited minimum corrosion resistance as TEL decreased to 198 #m. Zinc and its alloy exhibited localized corrosion under TEL while it was more uniform in bulk solution. There were two capacitive loops in high frequency （HF） and middle frequency （MF） respectively, with finite length diffusion in low frequency （LF） presented in EIS. For pure zinc under TEL below 300 pm an additional inductive loop presented in MF-LF. The corrosion products and morphology were respectively examined by X-ray diffraction （XRD）, FTIR （Fourier Transform Infra Red） and SEM-EDS. FTIR micro spectroscopy results indicated that the component of the corrosion products was similar at different section of the specimen surface but different in content.

关键词： Thin electrolyte layers EIS Cathodic polarization FTIR micro spectroscopy SEM

磁共振药代动力灌注扫描在鉴别段样强化肉芽肿性乳腺炎与浸润性导管癌中的价值研究

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磁共振成像 2024年第3期15卷 177-182页

作者：陈艳吴晓燕张敏黄学菁成建明郑李韵上海市宝山区中西医结合医院放射科上海201900 上海中医药大学附属曙光医院放射科上海201203 上海联影医疗科技股份有限公司上海201807

目的探讨基于压缩感知技术的磁共振药代动力灌注扫描对段样强化的特发性肉芽肿性乳腺炎(idiopathic granulomatous mastitis,IGM)与浸润性导管癌(invasive ductal carcinoma,IDC)的鉴别诊断价值。材料与方法回顾性分析27例段样强化、... 详细信息

目的探讨基于压缩感知技术的磁共振药代动力灌注扫描对段样强化的特发性肉芽肿性乳腺炎(idiopathic granulomatous mastitis,IGM)与浸润性导管癌(invasive ductal carcinoma,IDC)的鉴别诊断价值。材料与方法回顾性分析27例段样强化、无脓肿型IGM和15例IDC患者的临床及影像资料,均行磁共振药代动力灌注扫描。采用Fisher精确检验、t检验、χ^(2)检验比较两组月经状态、年龄、内部强化方式的差异,采用t检验、Mann Whitney U检验筛选出两组容积转运常数(volume transport constant,K^(trans))、速率常数(rate constant,K_(ep))、血管外细胞外间隙容积分数(extravascular extracellular volume fraction,Ve)值中的差异项,用二元logistic线性回归分析其与IDC的危险系数,并绘制受试者工作特征(receiver operating characteristic,ROC)曲线。结果两组年龄、月经状态差异均有统计学意义(P=0.001、0.003),而内部强化方式差异无统计学意义(P=0.883)。磁共振药代动力灌注扫描:IGM组K^(trans)值[(0.274±0.163)min^(-1)]低于IDC组[(0.451±0.257) min^(-1)],IGM组K_(ep)值[(0.618±0.245)min^(-1)]低于IDC组[(0.856±0.420) min^(-1)],且两组间K^(trans)及K_(ep)值的差异有统计学意义(P=0.013,0.012)。两组Ve值为IGM组(0.531±0.320)min^(-1)、IDC组(0.629±0.323)min^(-1),差异无统计学意义(P=0.182)。二元logistic线性回归:K^(trans)值的优势比(odds ratios,OR)=2.243[95%置信区间(confidence interval,CI):0.652~6.294](P=0.021),绘制ROC曲线显示,约登指数、敏感度、特异度分别为0.585、73.3%、85.2%,曲线下面积(area under the curve,AUC)=0.778 (95%CI:0.623~0.891)(P=0.001)。结论基于压缩感知技术的磁共振药代动力灌注扫描所得K^(trans)值对以段样强化为表现的IGM、IDC有鉴别诊断价值。

关键词：特发性肉芽肿性乳腺炎浸润性导管癌磁共振药代动力灌注扫描压缩感知磁共振成像

Effect of hot isostatic pressing nitrogen on the microstructure and properties of a Ti(C,N)-based cermet

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Rare Metals 2006年第4期25卷 321-325页

作者： YAN Xianmei XIONG Weihao YANG Yong zheng liyun State Key Laboratory of Die and Mould Technology Huazhong University of Science and Technology Wuhan 430074 China

The high-temperature, high-pressure hot isostatic pressing technology was used for depositing hard coatings on Ti（C, N）-based cermets. The rnicrostructure and properties of the sample were investigated using optical microscopy, scan- ning electron microscopy, X-ray diffraction, electron probe microanalysis, and microhardness tester. The results showed that the rich titanium and nitrogen in surface zone were induced by the heat treatment. The high nitrogen activity of the surface region was the driving force for outward transport of titanium and inward transport of tungsten in the cobalt binder. The toughness and hardness were improved and a hardness gradient was formed. It is the high-temperature, high-pressure N2 that enables closure of holes, thereby alleviating defects and prolonging tool life.

关键词： Ti(C, N)-based cermet hot isostatic pressing microstructure properties

DNMT3a在肺腺癌中的表达及癌细胞迁移的影响分析

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安徽医学 2024年第8期45卷 946-953页

作者：蒋梦龙郑丽云葛威康宁宁许峰张仁泉安徽医科大学第一附属医院普胸外科安徽合肥230022 安徽省儿童医院心血管科安徽合肥230051

目的探讨DNA甲基转移酶3a(DNMT3a)在肺腺癌中的表达水平及影响肺腺癌细胞迁移的分子机制。方法回顾性分析2023年1~12月在安徽医科大学第一附属医院胸外科接受手术治疗的41例肺腺癌患者临床资料,使用IHC和蛋白质印迹实验(WB)检测并分析DN... 详细信息

目的探讨DNA甲基转移酶3a(DNMT3a)在肺腺癌中的表达水平及影响肺腺癌细胞迁移的分子机制。方法回顾性分析2023年1~12月在安徽医科大学第一附属医院胸外科接受手术治疗的41例肺腺癌患者临床资料,使用IHC和蛋白质印迹实验(WB)检测并分析DNMT3a在41例患者肺腺癌组织及癌旁组织中的表达水平;通过分析TCGA数据库揭示DNMT3a与肺腺癌患者预后关系。慢病毒介导SK-LU-1和A549细胞系过表达或敲低DNMT3a,通过IHC、WB、实时荧光定量聚合链反应(qRT-PCR)、DNMT3a抑制剂实验观察DNMT3a对蜗牛家族转录因子(Snail)表达的影响;细胞划痕实验和Transwell细胞迁移实验检测过表达或敲低DNMT3a对肺腺癌细胞迁移的影响。结果DNMT3a高表达对比DNMT3a低表达的肺腺癌患者生存期较短,差异有统计学意义(P<0.01);DNMT3a和Snail在肺腺癌组织中较癌旁组织相比均高表达(P<0.01),且DNMT3a和Snail在肺腺癌组织中的表达呈正相关(r=0.612,P<0.01)。与对照组相比,过表达DNMT3a的SK-LU-1细胞中Snail表达上调并增加了肺腺癌细胞的迁移数量(P<0.01),敲低DNMT3a的A549细胞中Snail表达下调并减少了肺腺癌细胞的迁移数量(P<0.01)。结论DNMT3a在肺腺癌组织中高表达且与不良预后显著相关,DNMT3a通过上调Snail的表达促进肺腺癌细胞的迁移。

关键词：肺腺癌甲基化转移酶3a 蜗牛家族转录因子迁移上皮间质转化

表面处理制备Ti(C,N)基金属陶瓷功能梯度材料

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稀有金属材料与工程 2006年第A02期35卷 50-52页

作者：晏鲜梅熊惟皓郑立允华中科技大学模具技术国家重点实验室湖北武汉430074

用热等静压技术制备了Ti(C,N)基金属陶瓷功能梯度材料。对表面处理前后材料的组织结构,显微硬度,密度变化作了分析比较。并用EPMA对材料表面处理后的主要元素分布进行了分析测试,同时从热力学和孔隙度对材料性能影响的角度分析了其形成... 详细信息

用热等静压技术制备了Ti(C,N)基金属陶瓷功能梯度材料。对表面处理前后材料的组织结构,显微硬度,密度变化作了分析比较。并用EPMA对材料表面处理后的主要元素分布进行了分析测试,同时从热力学和孔隙度对材料性能影响的角度分析了其形成机理。

关键词： Ti(C,N)基金属陶瓷功能梯度材料热等静压技术氮化处理

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功能梯度金属陶瓷的制备与性能

稀有金属材料与工程 2005年第9期34卷 1389-1393页

作者：郑立允熊惟皓赵立新华中科技大学湖北武汉430074 河北工程学院河北邯郸056038

采用熔渗/氮化复合处理技术对TiC-TiN基、WC基金属陶瓷进行了高温高压熔渗/氮化处理,通过扫描电镜、能谱仪、X射线衍射等分析技术对其显微组织、成分及结构进行了分析。结果表明:经过高温高压熔渗/氮化处理,WC-Co金属陶瓷未形成梯度结构... 详细信息

采用熔渗/氮化复合处理技术对TiC-TiN基、WC基金属陶瓷进行了高温高压熔渗/氮化处理,通过扫描电镜、能谱仪、X射线衍射等分析技术对其显微组织、成分及结构进行了分析。结果表明:经过高温高压熔渗/氮化处理,WC-Co金属陶瓷未形成梯度结构;WC-TiC-Co金属陶瓷表面形成了TiN,但是从材料表面向内部的成分过渡存在明显的界面;TiC-TiN基金属陶瓷由表面到心部形成了梯度结构,其硬度自表面向心部呈现高-低-高的变化趋势,该金属陶瓷表面主要形成了Ti(C0.3N0.7)。

关键词：熔渗氮化金属陶瓷功能梯度材料