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Nano Research 2017年第3期10卷 897-907页

作者： Jung Sang Cho jin-Sung park Yun chan Kang Department of Materials Science and Engineering Korea University Anam-Dong Seongbuk-Gu Seou1136-713 Republic of Korea Department of Engineering Chemistry Chungbuk National University Chungbuk 361-763 Republic of Korea

Porous FeS nanofibers with numerous nanovoids for use as anode materials for sodium-ion batteries were prepared by electrospinning and subsequent sulfidation. The post-treatment of the as-spun Fe（acac）3-polyacrylonitrile composite nanofibers in an air atmosphere yielded hollow Fe2O3 nanofibers due to Ostwald ripening. The ultrafine Fe2O3 nanocrystals formed at the center of the fiber diffused toward the outside of the fiber via Ostwald ripening. On sulfidation, the Fe2O3 hollow nanofibers were transformed into porous FeS nanofibers, which contained numerous nanovoids. The formation of porosity in the FeS nanofibers was driven by nanoscale Kirkendall diffusion. The porous FeS nanofibers were very structurally stable and had superior sodium-ion storage properties compared with the hollow Fe2O3 nanofibers. The discharge capacities of the porous FeS nanofibers for the Ist and 150th cycles at a current density of 500 mA.g-1 were 561 and 592 mA.h-g-1, respectively. The FeS nanofibers had final discharge capacities of 456, 437, 413, 394, 380, and 353 mA-h.g-1 at current densities of 0.2, 0.5, 1.0, 2.0, 3.0, and 5.0 A.g-1, respectively.

关键词： iron sulfide sodium-ion batteries Kirkendall effect nanofibers electrospinning

Improved continuous precipitation kinetics and tensile properties of extruded AZ80 alloy through {10-12} twin formation

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Journal of Magnesium and Alloys 2023年第9期11卷 3323-3337页

作者： Hyun ji Kim Sumi Jo Sung Hyuk park Department of Materials Science and Metallurgical Engineering Kyungpook National UniversityDaegu 41566the Republic of Korea

This study investigates the effect of{10-12}deformation twins on the continuous precipitation behavior of an extruded Mg-8.0Al-0.5Zn-0.2Mn(AZ80)alloy during *** extruded AZ80 alloy is compressed along the transverse direction to introduce{10-12}twins,followed by an aging treatment at 300℃.The extruded material exhibits a twin-free microstructure with low internal strain energy,whereas the pre-twinned material possesses abundant{10-12}twins and has high internal strain *** aging results reveal that the peak-aging time of the pre-twinned material(1 h)is one-eighth of that of the extruded material(8 h).Although Mg_(17)Al_(12)continuous precipitates(CPs)are observed in both the peak-aged materials,these CPs are much smaller and more densely distributed in the pre-twinned material despite the significantly shorter aging *** CPs size in the peak-aged materials increases in the following order:twinned region in the pre-twinned material(0.47μm)

关键词： AZ80 alloy {10-12}twin Aging Continuous precipitation Tensile properties

Do In terest Rate Liberalizati on and Fin tech Mix?Impact on Shadow Deposits in China

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China & World Economy 2020年第1期28卷 4-22页

作者： Stephanie chan Yang ji Department of Finance School of Economics and WISEXiamen University Department of Finance School of Economics and Gregory and Paula Chow Center for Economics ResearchXiamen University

In this paper we attempt to characterize the stability of shadow deposits in China with interest rate liberalization and fintech *** emphasize that shadow banks provide higher but riskier returns and such characteristics affect the stability of shadow *** our setting,the stability of shadow deposits is influenced by two offsetting effects,namely:the patience effect,which makes investors more willing to wait because of the potentially higher returns;and the uncertainty effect,which makes investors more likely to withdraw as a result of higher *** liberalized interest rates,the patience effect will erode and the uncertainty effect will be heightened because the post-liberalization higher return of traditional banks undermines the importance of the extra return of shadow deposits to depositors,while preserving the importance of the risk *** development is modeled as a reduction in the withdrawal cost that facilitates *** affects the stability of shadow deposits because of their wider fintech *** should be cautious in pushing interest rate liberalization andfintech application alongside building a safety net for shadow banking.

关键词： bank run fintech interest rate liberalization shadow banking

Evolution of microstructure and tensile properties of cold-drawn hyper-eutectoid steel wires during post-deformation annealing

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Journal of Materials Science & Technology 2020年第6期41卷 1-11页

作者： Majid Jafari chan-Woo Bang Jong-chan Han Kyeong-Min Kim Seon-Hyeong Na chan-Gyung park Byeong-Joo Lee Department of Materials Science and Engineering POSTECH Pohang 37673 South Korea

Manufacturing temperatures of severely cold-drawn hyper-eutectoid steel wires are sufficiently high to influence the mobility of dislocations and alloy elements,thereby affecting the materials’mechanical ***,we describe the evolution of microstructure and tensile strength of the as-drawn 3.45 GPa steel wire during post-deformation annealing for 30 min at 150-450℃.Annealing at 150℃raised the strength to 3.77 GPa by age-hardening through activation of dislocations pinning by carbon,while further temperature rising up to 450℃caused a severe loss of *** was proved that annealing at 300 and 450℃destabilizes the lamellar microstructure,promoting the formation of carbon-deficient(Fe,Mn,Cr)3 C-type cementite particles with preferentially rounded and partially faceted *** at 450℃yielded the accumulation of Mn and Cr at the ferrite/particle interfaces,and their concentrations at the interfaces were dependent on the interface structure;i.e.,lower concentrations at rounded interfaces(formed through capillarity–driven coarsening of the spheroidized cementite),and higher concentrations at faceted interfaces(that are initially existing in the as-drawn state).Our proof-of-principle observations,supported by thermodynamic calculations and kinetic assessments,provide a pathway for understanding the changes in microstructural and tensile properties during manufacturing of the hyper-eutectoid steel wires.

关键词： Three-dimensional atom probe(3DAP) High resolution transmission electron microscopy(HRTEM) Nano-grained low-carbon steel Annealing Tensile behavior

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河南登封嵩岳寺唐代大照、乘如二碑残石考证

中国国家博物馆馆刊 2024年第3期 81-92页

作者：季爱民东北师范大学历史文化学院长春130024

大照与乘如是唐代北宗禅高僧。他们的石刻资料以不同的形式存世,需要澄清不同资料间的关系。比较登封嵩岳寺地宫出土的石刻残片与传世《大照碑》摹刻本的内容与书法,可知残石为《大照碑》的一部分,摹刻本的内容有遗漏。检验前人缀合《... 详细信息

大照与乘如是唐代北宗禅高僧。他们的石刻资料以不同的形式存世,需要澄清不同资料间的关系。比较登封嵩岳寺地宫出土的石刻残片与传世《大照碑》摹刻本的内容与书法,可知残石为《大照碑》的一部分,摹刻本的内容有遗漏。检验前人缀合《乘如碑》现存残石与石刻文献的成果,并结合拓本加以校勘,可以得到较为准确的碑文资料。旧拓本《乘如墓志》的内容与《乘如碑》相互验证或补充,为研究乘如生平的重要史料。

关键词：唐代大照禅师乘如禅师嵩岳寺北宗禅

Bisphosphonate use and gastrointestinal tract cancer risk:Meta-analysis of observational studies

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World Journal of Gastroenterology 2012年第40期18卷 5779-5788页

作者： Yun Hwan Oh chan Yoon Sang Min park Department of Family Medicine Seoul National University HospitalSeoul National University College of MedicineSeoul 110-774South Korea Seoul National University Hospital Seoul National University College of MedicineSeoul 110-774South Korea

AIM:To perform a meta-analysis of observational studies to further elucidate the relationship between oral bisphosphonate use and gastrointestinal cancer ***:Systematic literature search was conducted in MEDLINE,EMBASE,and the Cochrane Library to identify studies through January *** terms were "bisphosphonates" or trade names of the drugs,and "observational studies" or "cohort studies" or "case-control studies".Two evaluators reviewed and selected articles on the basis of predetermined selection criteria as followed:(1) observational studies(casecontrol or cohort studies) on bisphosphonate use;(2) with at least 2 years of follow-up;and(3) reported data on the incidence of cancer *** DerSimonian and Laird random effects model were used to calculate the pooled relative risk(RR) with 95% confidence interval(CI).Two-by-two contingency table was used to calculate the outcomes not suitable for *** meta-analyses were conducted for the type of cancer(esophageal,gastric and colorectal cancers).Sensitivity analyses were performed to examine the effect sizes when only studies with long-term follow-up(mean 5 years;subgroup 3 years) were ***:Of 740 screened articles,3 cohort studies and 3 case-control studies were included in the *** first,4 cohort studies and 3 case-control studies were selected for the analyses but one cohort study was excluded because the cancer outcomes were not categorized by type of gastrointestinal *** than 124 686 subjects participated in the 3 cohort *** mean follow-up time in all of the cohort studies combined was approximately 3.88 *** 3 casecontrol studies reported 3070 esophageal cancer cases and 15 417 controls,2018 gastric cancer cases and 10 007 controls,and 11 574 colorectal cancer cases and 53 955 *** percentage of study participants who used bisphosphonate was 2.8% among the cases and 2.9% among the *** meta-analysis of all the studies fo

关键词： Bisphosphonate Gastrointestinal tract can-cer Esophageal cancer Gastric cancer Colorectal can-cer Meta-analysis

Refractive index sensing based on a twisted nano-kirigami metasurface

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Photonics Research 2024年第2期12卷 218-225页

作者： SHUQI QIAO XIAOCHEN ZHANG QINGHUA LIANG YANG WANG chanG-YIN ji XIAOWEI LI LAN jiANG SHUAI FENG HONGLIAN GUO jiAFANG LI School of Science Minzu University of ChinaBeijing 100081China Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(Ministry of Education) Beijing Key Laboratory of Nanophotonics&Ultrafine Optoelectronic Systemsand School of PhysicsBeijing Institute of TechnologyBeijing 100081China Laser Micro/Nano Fabrication Laboratory School of Mechanical EngineeringBeijing Institute of TechnologyBeijing 100081China

Plasmonic sensing technology has attracted considerable attention for high sensitivity due to the ability to effectively localize and manipulate *** this study,we demonstrate a refractive index(RI)sensing scheme based on open-loop twisted meta-molecule arrays using the versatile nano-kirigami *** sensing has the features of a small footprint,flexible control,and simple *** engineering the morphology of meta-molecules or the RI of the ambient medium,the chiral surface lattice resonances can be significantly enhanced,and the wavelength,intensity,and sign of circular dichroism(CD)can be flexibly *** the relation between the wavelength of the CD peak and the RI of the superstrate,the RI sensor achieves a sensitivity of 1133 nm/***,we analyze these chiroptical responses by performing electromagnetic multipolar decomposition and electric field *** study may serve as an ideal platform for applications of RI measurement and provide new insights into the manipulation of chiral light–matter interactions.

关键词： twisted chiral index

Incremental forming of free surface with magnesium alloy AZ31 sheet at warm temperatures

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中国有色金属学会会刊：英文版 2008年第A1期18卷 165-169页

作者： Y.H.ji J.J.park Department of Mechanical and System Design Engineering Hongik University

The formabilityof AZ31 sheet begins to increase drastically at 150℃.The incremental forming technique was thus applied to AZ31 sheet at 150℃to utilize the formability to its fullest capacity at the lowest possible temperature for forming applications.A surface scanning technique was used followed by the tool path generation to incrementally form an egg *** thorough examination of various tool paths,the surface was most successfully produced by forming an intermediate shape followed by a series of tool *** scale stickers were devised to improve the accuracy in the measurement of grid deformation.

关键词：金属材料数控成形加工 AZ31镁合金板材

Environmental influence in the forested area toward human health: incorporating the ecological environment into art psychotherapy

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Journal of Mountain Science 2020年第4期17卷 992-1000页

作者： Ju-hyoung LEE ji-sook park Sunnam CHOI Department of Forest Resources and Landscape Architecture Yeungnam UniversityGyeongsan 38541South Korea Department of Art Therapy Yeungnam UniversityGyeongsan 38541South Korea

This study on the development of a psychotherapy program based on the relationship between forests and human health focused on actively considering the natural ecological environment. This study categorized and compared an art psychotherapy program that simply moved to an outdoor space and a forest-art therapy program that actively utilized the forest environment as a medium. The characteristics of the natural environment, such as openness, change, and diversity, shortened the amount of time participants took to develop a rapport and open up and played a vital role in recovering mental health. After a bold attempt at integrating forest environment and art psychotherapy by going beyond outdoor art therapy, there were significant results pertaining to improvements in mental disorders in today’s society, including stress vulnerabilities, depression, anxiety, and aggression. The research results verified that the developed forest-art therapy method had greater efficacy in relation to both the Stress Vulnerability-Interpersonal Sensitivity Scale and the Stress Vulnerability-Self-Regulation Scale.

关键词： Forest therapy Human health Healing forest Art therapy Forest environment

Acceleration of aging behavior and improvement of mechanical properties of extruded AZ80 alloy through(10–12) twinning

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Journal of Magnesium and Alloys 2023年第2期11卷 671-683页

作者： Hyun ji Kim Ye jin Kim Sung Hyuk park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea

The effects of pre-existing {10–12} extension twins on the precipitation behavior of an extruded AZ80 material during aging and on its mechanical properties after peak aging are investigated. The material containing {10–12} twins-which are formed by compression before aging(twinned material)-has a finer grain size and higher dislocation density than the extruded material. Although the peak hardnesses of the twinned and extruded materials are almost the same, the time to reach the peak hardness is considerably shorter in the former material than in the latter(4 h and 24 h, respectively). In the twinned material, the high dislocation density of the {10–12} twins promotes continuous precipitation, which results in the formation of numerous fine Mg17Al12precipitates within the twins in the early stage of *** formation of these continuous precipitates reduces the driving force for discontinuous precipitation, which consequently suppresses the formation and growth of coarse Mg17Al12precipitates at the grain boundaries. Despite its shorter peak-aging time, the 4 h-peak-aged twinned material shows higher tensile strength and elongation than the 24 h-peak-aged extruded material. These higher mechanical properties of the former material are attributed primarily to the presence of more abundant fine continuous precipitates, which are effective in strengthening the material, and less abundant coarse discontinuous precipitates, which can act as crack initiation sites. These results demonstrate that the introduction of {10–12} twins into wrought Mg–Al-based alloys can accelerate the Mg17Al12precipitation kinetics considerably and improve the strength and ductility of the peak-aged alloys simultaneously.

关键词： AZ80 alloy Twin Aging Precipitation Tensile properties