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Thermal studies of individual Si/Ge heterojunctions--The influence of the alloy layer on the heterojunction

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Journal of Materiomics 2020年第2期6卷 248-255页

作者： Sien Wang dongchao xu Ramya Gurunathan G.Jeffrey Snyder Qing Hao Department of Aerospace and Mechanical Engineering University of ArizonaTucsonAZ85721-0119USA Department of Materials Science and Engineering Northwestern UniversityEvanstonIL60208USA

Phonon transport across an interface is of fundamental importance to applications ranging from electronic and optical devices to thermoelectric *** phonon scattering by an interface can dramatically suppress the thermal transport,which can benefit thermoelectric applications but create problems for the thermal management of electronic/optical *** this aspect,existing molecular dynamics simulations on phonon transport across various interfaces are often based on estimates of atomic structures and are seldom compared with measurements on real *** this work,planar Si/Ge heterojunctions formed by film-wafer bonding are measured for the interfacial thermal resistance (R_(K)) that is further compared with predictions from existing simulations and analytical *** twist angle between a 70-nm-thick Si film and a Ge wafer is varied to check the influence of the crystal *** transmission electron microscopy studies are carried out to better understand the interfacial atomic *** is found that the alloyed interfacial layer with mixed Si and Ge atoms dominates the measured thermal resistance(R_(K)).Some oxygen impurities may also help to increase RK due to the formation of glassy *** this,RK reduction should be focused on how to minimize the interdiffusion of Si and Ge atoms during the formation of a Si/Ge heterojunction.

关键词： Thermal boundary resistance Si/Ge heterojunction Film-wafer bonding Phonon

Largely reduced cross-plane thermal conductivity of nanoporous In0.1Ga0.9N thin films directly grown by metal organic chemical vapor deposition

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Frontiers in Energy 2018年第1期12卷 127-136页

作者： dongchao xu Quan WANG xuewang WU Jie ZHU Hongbo ZHAO Bo XIAO Xiaojia WANG Xiaoliang WANG Qing HAO Aerospace & Mechanical Engineering University of Arizona 1130 NMountain Ave Tucson AZ 85721 USA Key laboratory of Semiconductor Materials Science Institute ofSemiconductors Chinese Academy of Sciences Beijing 100083 China Department of Mechanical Engineering University of Minnesota IllChurch St. SE Minneapolis MN 55455 USA

In recent year, nanoporous Si thin films have been widely studied for their potential applications in thermoelectrics, in which high thermoelectric performance can be obtained by combining both the dramatically reduced lattice thermal conductivity and bulk-like elec- trical properties. Along this line, a high thermoelectric figure of merit （ZT） is also anticipated for other nanoporous thin films, whose bulk counterparts possess superior electrical properties but also high lattice thermal conductivities. Numerous thermoelectric studies have been carried out on Si-based nanoporous thin fills, whereas cost-effective nitrides and oxides are not systematically studied for similar thermoelectric benefits. In this work, the cross-plane thermal conductivities of nanoporous ***.9N thin films with varied porous patterns were measured with the time-domain thermoreflectance techni- que. These alloys are suggested to have better electrical properties than conventional SixGel x alloys; however, a high ZT is hindered by their intrinsically high lattice thermal conductivity, which can be addressed by introdu- cing nanopores to scatter phonons. In contrast to previous studies using dry-etched nanopores with amorphous poreedges, the measured nanoporous thin films of this work are directly grown on a patterned sapphire substrate to minimize the structural damage by dry etching. This removes the uncertainty in the phonon transport analysis due to amorphous pore edges. Based on the measurement results, remarkable phonon size effects can be found for a thin film with periodic 300-nm-diameter pores of different patterns. This indicates that a significant amount of heat inside these alloys is still carried by phonons with -300 nm or longer mean flee paths. Our studies provide important guidance for ZT enhancement in alloys of nitrides and similar oxides.

关键词： nanoporous film thermoelectrics phonon,mean free path diffusive scattering

Improvement of cardiac function by hepatocyte growth factor via intracoronary transfection in the swine myocardial infarction model

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Journal of Nanjing Medical University 2006年第4期20卷 201-203页

作者： Wei Wang Zhijian Yang dongchao Ma Shunlin xu Yourong Zhang Yuqing Zhang Liansheng Wang Bo Chen Kejiang Cao Wenzhu Ma Department of Cardiovascular Medicine the First Affiliated Hospital Nanjing Medical University Nanjing 210029 China

Objective： To study the amelioration effect of AdenovirusS-mediated human hepatocyte growth factor （AdsHGF） on postinfarction heart failure in the swine myocardial infarction model. Methods： Twelve SuZhong young swine were randomly divided into 2 groups with 6 swine in each group： Ad5-HGF-treated group and null-Ad5 group. Four weeks after ligation at left anterior descending coronary artery in swine hearts, Ad5-HGF was transferred to the swine myocardium. Simultaneously, Gated myocardial perfusion imaging was performed to evaluate cardiac perfusion and heart function. After three weeks, Gated myocardial perfusion imaging was performed again, then the hearts were harvested and sectioned to examine the expression of HGF through ELISA. Results： High expression of human HGF was observed in the myocardium of Ad5-HGF-treated group. From 4 weeks to 7 weeks after operation, Left ventricular ejection fraction was increased in Ad5-HGF-treated group. The improvement in LVEF was greater in Ad5-HGF-treated group than that in null-Ad5 group at 7 weeks after operation. Cardiac perfusion was significantly improved in the Ad5-HGF-treated group. Conclusion： High expression of human HGF was observed in the myocardium through intracoronary transfection, which suggests that HGF can ameliorate heart function in swine with postinfarction heart failure.

关键词： gene therapy postinfarction heart failure hepatocyte growth factor

敲低RBX1通过下调PHF5A抑制胰腺癌细胞增殖,迁移和侵袭并促进凋亡

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重庆医科大学学报 2023年第11期48卷 1314-1322页

作者：张菁阎优优徐栋超张博浙江大学医学院附属杭州市第一人民医院转化医学研究中心杭州310000 浙江大学医学院附属杭州市第一人民医院消化内科杭州310000

目的:研究环盒蛋白1(ring-finger protein 1,RBX1)对胰腺癌(pancreatic adenocarcinoma,PAAD)细胞增殖、凋亡、迁移和侵袭的作用及其潜在的作用机制。方法:利用基因表达谱交互式分析网站(gene expression profile interactive analysis web⁃site,GEPIA),实时荧光定量聚合酶链反应(quantitative reverse transcription-polymerase chain reaction,qRT-PCR)、Western blot检测RBX1在PAAD组织、细胞中的表达和预后价值。使用细胞计数试剂盒-8(cell counting kit-8,CCK-8)、细胞克隆形成能力实验、脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(terminal deoxynucleotidyl transferase dUTP nick end labeling,TUNEL)、细胞划痕实验、Transwell实验检测RBX1敲低对胰腺癌-1(pancreatic carcinoma-1,PANC-1)细胞增殖、凋亡、迁移和侵袭的影响。通过LinkedOmics网站研究PAAD中RBX1和PHD锌指结构域蛋白5A(plant homodomain finger-like domaincontaining protein 5A,PHF5A)的相关性。qRT-PCR和Western blot检测RBX1敲低后PHF5A的表达,进行功能拯救实验。结果:RBX1在PAAD组织和细胞系中高表达,与不良预后相关(P<0.05)。RBX1敲低抑制PANC-1细胞增殖、迁移和侵袭,促进细胞凋亡(P<0.05)。RBX1和PHF5A在PAAD中具有相关性(r=0.692),且RBX1正向调控PHF5A表达(P<0.05)。功能拯救实验表明PHF5A过表达部分逆转了RBX1敲低对PANC-1细胞增殖、迁移、侵袭和凋亡的作用(P<0.05)。结论:RBX1敲低通过下调PHF5A表达抑制PANC-1细胞增殖、迁移和侵袭,促进凋亡。

关键词：环盒蛋白1 PHD锌指结构域蛋白5A 胰腺癌增殖凋亡侵袭迁移

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基于子空间辨识和增广模型的烟气脱硝系统预测控制

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热力发电 2016年第6期45卷 26-32,39页

作者：王勇徐东超林涛王鹏西安交通大学电子与信息工程学院陕西西安710049

选择性催化还原(SCR)烟气脱硝系统具有大惯性、大延迟的特点,常用的PID控制器不能很好地适用于该系统。结合某火电机组实际运行数据,建立了基于子空间方法的SCR烟气脱硝系统模型,并将模型计算结果与实测数据进行对比,验证了模型具有较... 详细信息

选择性催化还原(SCR)烟气脱硝系统具有大惯性、大延迟的特点,常用的PID控制器不能很好地适用于该系统。结合某火电机组实际运行数据,建立了基于子空间方法的SCR烟气脱硝系统模型,并将模型计算结果与实测数据进行对比,验证了模型具有较强的鲁棒性。将子空间辨识所得脱硝系统状态空间模型进行变换,得到其增广模型,设计了基于增广模型的预测控制器,并将该控制器仿真结果与系统原有PID控制器输出结果及实际运行数据进行了对比。结果表明,与系统原有PID控制器相比,本文设计的预测控制器能够很好地跟踪脱硝系统期望,具有更好的控制效果。

关键词： SCR烟气脱硝子空间辨识状态空间模型增广模型模型预测控制 PID

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电磁搅拌对Mg-Al-Si合金组织的影响

特种铸造及有色合金 2004年第3期24卷 26-28页

作者：杨必成杜东朝朱学新徐骏谢丽君北京有色金属研究总院

研究了不同电磁搅拌频率和不同冷却速度对MgAl9Si合金凝固组织的影响 ,比较了搅拌和不搅拌两种工艺下得到的不同组织。结果表明 ,电磁搅拌能完全抑制树枝晶的形成 ,提高搅拌频率能使α Mg趋于等轴化 ;延长搅拌时间不能改变晶粒形貌 ,只... 详细信息

研究了不同电磁搅拌频率和不同冷却速度对MgAl9Si合金凝固组织的影响 ,比较了搅拌和不搅拌两种工艺下得到的不同组织。结果表明 ,电磁搅拌能完全抑制树枝晶的形成 ,提高搅拌频率能使α Mg趋于等轴化 ;延长搅拌时间不能改变晶粒形貌 ,只能使组织变得更加粗大 ;此外 ,电磁搅拌还能促进凝固过程中Mg2 Si相的形核。

关键词： Mg-Al-Si 电磁搅拌半固态浆料组织形貌

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基于声景特点的深圳城市建成环境研究

现代城市研究 2019年第9期34卷 75-81页

作者：徐东超余磊康健哈尔滨工业大学(深圳) 深圳市盐田区城市更新和土地整备局伦敦大学学院(UCL)

建成环境是声景产生的基础条件,由环境声带来的"听觉"景观在一定程度上也反映了建成环境特点。以深圳为例,利用实地调研、统计分析等方法,研究了深圳市6个行政区域内不同建成环境的声景状况,提出了深圳市15种典型建成环境与其所对应的... 详细信息

建成环境是声景产生的基础条件,由环境声带来的"听觉"景观在一定程度上也反映了建成环境特点。以深圳为例,利用实地调研、统计分析等方法,研究了深圳市6个行政区域内不同建成环境的声景状况,提出了深圳市15种典型建成环境与其所对应的声景之间的关联模型,从建设强度和景观绿化方面量化了建成环境指标与声景指标之间的关系。研究发现,二者之间呈显著相关,其拟含度在0.4~0.8之间。本研究旨在从声景的角度为生态型城市建设和规划提供有益指导。

关键词：城市建成环境声景相关性深圳

基于CODESYS平台的城轨列车网络控制系统软件开发

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智慧轨道交通 2023年第6期60卷 40-44页

作者：赵鹏徐东超刘明希林晓琳中车青岛四方车辆研究所有限公司山东青岛266031

为了实现对城轨列车的控制和监测,提出了基于CODESYS平台的列车网络控制系统软件开发方法。首先介绍了CODESYS的平台特点和软件架构,在此基础上研发了TCMS软件开发平台;然后描述了基于该平台开发应用软件的流程;接着根据城轨列车的功能... 详细信息

为了实现对城轨列车的控制和监测,提出了基于CODESYS平台的列车网络控制系统软件开发方法。首先介绍了CODESYS的平台特点和软件架构,在此基础上研发了TCMS软件开发平台;然后描述了基于该平台开发应用软件的流程;接着根据城轨列车的功能需求开发了中央控制单元的逻辑程序;最后以某线路地铁列车为应用对象,验证了自研平台及软件具有较强的扩展性和实用性,可以满足城轨列车控制和诊断需求。

关键词：城轨列车网络控制系统 CODESYS 开发平台软件开发

基于工业以太网的高速磁浮列车车载监控系统研究

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智慧轨道交通 2022年第5期59卷 65-70页

作者：徐东超赵鹏李宗亮盖猛中车青岛四方车辆研究所有限公司山东青岛266031

以磁浮列车国产化为目标,介绍了高速磁浮列车的车载监控系统架构。为实现列车的诊断和控制功能,设计了车载诊断和控制系统。诊断系统采用两级传输网络,采集设备状态信息并进行分析和诊断;控制系统采用双路冗余方式,实现悬浮、导向和制... 详细信息

以磁浮列车国产化为目标,介绍了高速磁浮列车的车载监控系统架构。为实现列车的诊断和控制功能,设计了车载诊断和控制系统。诊断系统采用两级传输网络,采集设备状态信息并进行分析和诊断;控制系统采用双路冗余方式,实现悬浮、导向和制动等安全控制功能。车载监控系统通过工业以太网统一通信制式,简化网络接口形式,降低系统复杂度,提高通信带宽和实时性;通过热备冗余的控车方式,优化了网络布局,提高了列车的性能和可靠性。

关键词：高速磁浮列车车载监控系统诊断系统控制系统工业以太网