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Body-centered-cubic martensite and the role on room-temperature tensile properties in Si-added SiVCrMnFeCo high-entropy alloys

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Journal of Materials Science & Technology 2021年第17期76卷 222-230页

作者： Yong Hee Jo Junha Yang Won-Mi Choi Kyung-Yeon Doh donghwa lee Hyoung Seop Kim Byeong-Joo lee Seok Su Sohn Sunghak lee Center for High Entropy Alloys Pohang University of Science and TechnologyPohang 37673South Korea Department of Materials Science and Engineering Division of Advanced Materials SciencePohang University of Science and TechnologyPohang 37673South Korea Graduate Institute of Ferrous Technology Pohang University of Science and TechnologyPohang 37673South Korea Department of Materials Science and Engineering Korea UniversitySeoul 02841South Korea

We present a new class of metastable high-entropy alloys(HEAs),triggering deformation-induced martensitic transformation(DIMT)from face-centered-cubic(FCC)to body-centered-cubic(BCC),i.e.,BCC-DIMT.Through the ab-initio calculation based on 1 st order axial interaction model and combined with the Gibbs free energy calculation,the addition of Si is considered as a critical element which enables to reduce the intrinsic stacking fault energy(ISFE)in Si_xV_((9-x))Cr_(10)Mn_5 Fe_(46)Co_(30)(x=2,4,and 7 at.%)alloy system.The ISFE decreases from-30.4 to-35.5 mJ/m^(2)as the Si content increases from 2 to 7 at.%,which well corresponds to the reduced phase stability of FCC against HCP.The BCC-DIMT occurs in all the alloys via intermediate HCP martensite,and the HCP martensite provides nucleation sites of BCC martensite.Therefore,the transformation rate enhances as the Si content increases in an earlier deformation ra nge.However,the BCC-DIMT is also affected by the phase stability of FCC against BCC,and the stability is the highest at the Si content of 7 at.%.Thus,the 7Si alloy presents the moderate transformation rate in the later deformation range.Due to the well-controlled transformation rate and consequent strain-ha rdening rate,the 7Si alloy possesses the superior combination of strength and ductility beyond 1 GPa of tensile strength at room temperature.Our results suggest that the Si addition can be a favorable candidate in various metastable HEAs for the further property improvement.

关键词： High-entropy alloy(HEA) Deformation-induced martensitic transformation(DIMT) Phase stability Stacking fault energy(SFE)

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通过4-磺基苯甲酸单钾盐抑制离子迁移以实现效率为22.7%的稳定钙钛矿太阳能电池

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Science China Materials 2022年第12期65卷 3368-3381页

作者：白乐姚方王锐刘白白何冬梅周倩王文奇徐寸云胡小波陈少强宋群梁周廷伟 donghwa lee 赵鹏君陈聪杨华林乾乾臧志刚陈江照 Key Laboratory of Optoelectronic Technology&Systems(Ministry of Education) College of Optoelectronic EngineeringChongqing UniversityChongqing 400044China Key Lab of Artificial Micro-and Nano-Structures of Ministry of Education of China School of Physics and TechnologyWuhan UniversityWuhan 430072China Department of Electronic Engineering East China Normal UniversityShanghai 200241China Institute for Clean Energy and Advanced Materials School of Materials and EnergySouthwest UniversityChongqing 400715China School of Physical Science and Technology Southwest UniversityChongqing 400715China Department of Materials Science and Engineering Pohang University of Science and Technology(POSTECH)Pohang 37673Korea Xinjiang Technical Institute of Physics and Chemistry Chinese Academy of SciencesUrumqi 830011China School of Material Science and Engineering State Key Laboratory of Reliability and Intelligence of Electrical EquipmentHebei University of TechnologyTianjin 300130China Spallation Neutron Source Science Center Institute of High Energy PhysicsUniversity of Chinese Academy of Sciences(CAS)Dongguan 523803China

晶界处的深能级缺陷和严重的卤素离子迁移对进一步提高钙钛矿太阳能电池的稳定性和效率以及消除迟滞现象提出了严峻的挑战.本文报道了一种大尺寸强配位的有机阴离子晶界锚定策略来抑制离子迁移并钝化薄膜缺陷.本策略通过将含有大尺寸有... 详细信息

晶界处的深能级缺陷和严重的卤素离子迁移对进一步提高钙钛矿太阳能电池的稳定性和效率以及消除迟滞现象提出了严峻的挑战.本文报道了一种大尺寸强配位的有机阴离子晶界锚定策略来抑制离子迁移并钝化薄膜缺陷.本策略通过将含有大尺寸有机阴离子的钾盐(4-磺基苯甲酸单钾盐,SAMS)加入到钙钛矿前驱液中来实现.研究表明,阴离子两端的C=O和/或S=O能够与未配位的Pb^(2+)离子和/或卤化物空位之间发生强配位作用,阴离子中的–OH能够与甲脒阳离子形成氢键,以上化学作用使阴离子紧紧锚定在晶界处.SAMS不仅能够钝化浅能级缺陷,而且能够更有效地钝化深能级缺陷.该晶界锚定策略能降低钙钛矿薄膜的缺陷密度、延长载流子寿命和抑制离子迁移,提高电池的效率和稳定性以及消除迟滞效应.结果表明,基于SAMS改性的电池实现了22.7%的效率,而对照器件显示了20.3%的效率.未封装改性的器件在60℃加热老化1320小时后几乎没有发生衰减.

关键词：钙钛矿太阳能电池离子迁移有机阴离子载流子寿命深能级缺陷迟滞现象迟滞效应化学作用

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Aluminum nitride waveguide beam splitters for integrated quantum photonic circuits

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光子学研究:英文版 2023年第7期11卷 1196-1202页

作者： HYEONG-SOON JANG donghwa lee HYUNGJUN HEO YONG-SU KIM HYANG-TAG LIM SEUNG-WOO JEON SUNG MOON SANGIN KIM SANG-WOOK HAN HOJOONG JUNG Center for Quantum Information Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Department of Electrical and Computer Engineering Ajou UniversitySuwon 16499Republic of Korea Division of Nano and Information Technology KIST SchoolKorea University of Science and TechnologySeoul 02792Republic of Korea

We demonstrate integrated photonic circuits for quantum devices using sputtered polycrystalline aluminum nitride(Al N)on insulator.On-chip Al N waveguide directional couplers,which are one of the most important components in quantum photonics,are fabricated and show the output power splitting ratios from 50:50 to 99:1.Polarization beam splitters with an extinction ratio of more than 10 d B are also realized from the Al N directional couplers.Using the fabricated Al N waveguide beam splitters,we observe Hong–Ou–Mandel interference with a visibility of 91.7%±5.66%.

关键词： waveguide quantum beam

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MicroRNAs in pancreatic ductal adenocarcinoma

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World Journal of Gastroenterology 2011年第7期17卷 817-827页

作者： Jong Y Park James Helm Domenico Coppola donghwa Kim Mokenge Malafa Seung Joon Kim Division of Cancer Prevention and Control Moffitt Cancer Center FL 33612 United States Gastrointestinal Tumor Program Moffitt Cancer Center FL 33612 United States Department of Anatomic Pathology Moffitt Cancer Center FL 33612 United States Department of Molecular Oncology MoffittCancer Center FL 33612 United States Department of Internal Medicine Collegeof Medicine the Catholic University of Korea Seoul 137-040South Korea

Ductal adenocarcinoma of the pancreas is a lethal cancer for which the only chance of long-term survival belongs to the patient with localized disease in whom a potentially curative resection can be done. Therefore, biomarkers for early detection and new therapeutic strategies are urgently needed. miRNAs are a recently discovered class of small endogenous non-coding RNAs of about 22 nucleotides that have gained attention for their role in downregulation of mRNA expression at the post-transcriptional level. miRNAs regulate proteins involved in critical cellular processes such as differentiation, proliferation, and apoptosis. Evidence suggests that deregulated miRNA expression is involved in carcinogenesis at many sites, including the pancreas. Aberrant expression of miRNAs may upregulate the expression of oncogenes or downregulate the expression of tumor suppressor genes, as well as play a role in other mechanisms of carcinogenesis. The purpose of this review is to summarize our knowledge of deregulated miRNA expression in pancreatic cancer and discuss the implication for potential translation of this knowledge into clinical practice.

关键词： microRNA 胰腺癌 miRNA mRNA表达放松管制抑癌基因生物标志物转录后水平

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留学生健康App使用的影响分析

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西南科技大学学报（哲学社会科学版） 2023年第4期40卷 87-93页

作者：郑东和上海大学新闻与传播学院上海200072

本文基于计划行为理论(TPB)考察了来华留学生群体使用健康类App对其采取健康行为意愿的影响,以及可能的积极地自我健康管理的作用。本文以在华的韩国、马来西亚学生群体(N=501)为样本,对理论模型拓展的适配度以及各影响因素的中介以及... 详细信息

本文基于计划行为理论(TPB)考察了来华留学生群体使用健康类App对其采取健康行为意愿的影响,以及可能的积极地自我健康管理的作用。本文以在华的韩国、马来西亚学生群体(N=501)为样本,对理论模型拓展的适配度以及各影响因素的中介以及调节作用进行了依次分析。研究结果发现,使用健康App的行为对来华留学生的健康行为态度、健康行为主观规范以及健康知觉行为控制有正向影响。此外,健康行为态度、健康行为主观规范以及健康知觉行为控制在使用健康App和采取健康行为的意愿之间起中介作用。留学生国别对提高使用健康App意愿的行为态度和采取健康行为的主观规范有积极的调节作用。这项研究深入地揭示了来华留学生采取健康行为的前序因素及各因素的影响关系,为未来健康行为方向的研究提供了研究思路。

关键词：来华留学生健康App 健康行为

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