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Conceptual Design of Hybrid Cable-Stayed Bridge with Central Span of 1000 m Using UHPC

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Engineering（科研） 2013年第9期5卷 744-750页

作者： Hyejin Yoon Won Jong Chin hee seok Kim moon Seoung Keum Young Jin Kim Global Technology Cooperation Center Korea Institute of Construction Technology Goyang South Korea Structural Engineering Research Division Korea Institute of Construction Technology Goyang South Korea

Ultra-high performance concrete (UHPC) is featured by a compressive strength 5 times higher than that of ordinary concrete and by a high durability owing to the control of the chloride penetration speed by its dense structure. The high strength characteristics of UHPC offer numerous advantages like the reduction of the quantities of cables and foundations by the design of a lightweight superstructure in the case of the long-span bridge preserving its structural performance through axial forces and structures governed by compression. This study conducted the conceptual design of a hybrid cable-stayed bridge with central span of 1000 m and exploiting 200 MPa-class UHPC. The economic efficiency of the conceptual design results of the hybrid cable-stayed bridge with central span of 1000 m and of Sutong Bridge, the longest cable-stayed bridge in the world, was analyzed.

关键词： Ultra-High Performance Concrete UHPC Cable-Stayed Bridge 200 MPa-Class Sutong Bridge

Tm^(3+)-Doped Oxyfluoride Silicate Glasses for TDFA

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光学学报 2003年第S1期23卷 84-85页

作者： Doo-hee Cho Hong-seok Seo Bong-Je Park Yong-Gyu Choi Optical Communication Device Dept. Electronic and Telecommunication Research Institute 161 Kajong-dong Yusong-gu Daejon 305-350 Korea

The fluorine doping along with heavy metal oxides was remarkably raised the lifetime and the quantum efficiency of 3H4 in silicate glasses. The fluorine doping changed the local structure around Tm3+ ions, then low energy vibrations related to fluorine are considered to largely reduce the multi-phonon relaxation rates in the oxyfluoride silicate glasses.

关键词： quantum efficiency heavy metal

Pravastatin activates PPARα/PPARγexpression in the liver and gallbladder epithelium of hamsters

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Hepatobiliary & Pancreatic Diseases International 2011年第2期10卷 185-190页

作者： seok Ho Dong Jin Lee Dong hee Koh Min Ho Choi Hyun Joo Jang Sea Hyub Kae Division of Gastroenterology Department of Internal MedicineKyung Hee University College of Medicine Division of Gastroenterology Department of Internal MedicineHallym University College of Medicine

BACKGROUND:Our earlier study with cultured gallbladder epithelial cells demonstrated that statins(HMG-CoA reductase inhibitors)activate the expression of PPARαand PPARγ, consequently blocking the production of pro-inflmmatory *** present study used hamsters to investigate the effects of pavastatin on PPARα/PPARγexpression in the liver and gallbladder epithelium,and to determine whether pravastatin suppresses cholesterol crystal formation in the gallbladder. METHODS:A total of 40 Golden Syrian male hamsters(4 weeks old)were randomly assigned to four groups(basal diet control; basal diet+pavastatin;high cholesterol diet;high cholesterol diet+pravastatin).All hamsters were 11 weeks old at the end of the *** liver,gallbladder and bile were harvested. Immunohistochemical staining and Western blotting for PPARαand PPARγwere performed in the liver and gallbladder. A drop of fresh bile was examined for cholesterol crystals under a microscope. RESULTS:In the gallbladder and liver of the hamsters, pravastatin activated the PPARαand PPARγexpression of gallbladder epithelial cells and hepatocytes,and particularly the response of PPARγwas much stronger than that of PPARα. Pravastatin suppressed the formation of cholesterol gallstones or crystals in the gallbladder. CONCLUSION:Pravastatin is an effective medication to activate PPARs(especially PPARγ)in the liver and the gallbladder epithelium of hamsters,and contributes to the prevention of gallstone formation.

关键词： pravastatin PPARα PPARγ hamster gallstone

Proximate and mineral components of Viscum album var. coloratum grown on eight different host tree species

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Journal of Forestry Research 2019年第4期30卷 1245-1253页

作者： Chul-Woo Kim Chan-Hoon An Hyun-seok Lee Jae-Seon Yi Eun Ju Cheong Sang-Hyun Lim hee-Yeon Kim Forest Bioresources Department National Institute of Forest Science39 OnjeongroGwonseon-guSuwon 16631Republic of Korea Forest Medicinal Resources Research Center National Institute of Forest ScienceSobaek-ro 2009PunggiYoungjuGyungsangbuk-do 36040Republic of Korea Program of Forest Resources Division of Forest ScienceCollege of Forest and Environmental SciencesKangwon National UniversityChuncheon 24341Republic of Korea Agriproduct Processing Experiment Station Gangwon-do Agicultural Research and Experiment ServicesChuncheon 24203Republic of Korea

Mistletoes are parasite plants growing on various tree species,taking nutrients from the *** compounds of mistletoe were used in medicine and these mistletoes were commonly collected from oak species that were not well *** analyzed the nutritional value by measuring proximate and mineral components of Korean mistletoe(Viscum album ***)from various host *** was the most proximate component in both leaves and twigs followed crude protein,crude fiber,crude ash and crude *** the contents of the proximate components and minerals varied among hosts and between plant parts,leaves contained higher crude protein and ash,and more minerals except for magnesium than twigs,although no significant difference was found inmistletoe grown on Prunus *** were significant differences of proximate and mineral contents depending on the host *** grown on Chaenomeles sinensis contained higher levels of carbohydrates,crude fat,crude ash,magnesium,calcium,sodium,iron,and zinc than mistletoe grown on other *** grown on *** contained high mineral levels of potassium,copper and *** nutritional value of mistletoes were greatly influenced by the host species but among the hosts,specific nutrients accumulated in leaves more than in twigs,and vice *** on the analysis,Korean mistletoe contains relatively good quality of nutrients and has high potential for dietary supplements as well as for medicinal compounds.

关键词： Mistletoe Viscum album var coloratum Proximate compositions Mineral contents Nutritional value Host species

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.,*** 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 *** 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 *** BCC-DIMT occurs in all the alloys via intermediate HCP martensite,and the HCP martensite provides nucleation sites of BCC ***,the transformation rate enhances as the Si content increases in an earlier deformation ra ***,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 *** 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 *** 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)

Early extrahepatic recurrence as a pivotal factor for survival after hepatocellular carcinoma resection:A 15-year observational study

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World Journal of Gastroenterology 2022年第36期28卷 5351-5363页

作者： Jae Hyun Yoon Sung Kyu Choi Sung Bum Cho hee Joon Kim Yang seok Ko Chung Hwan Jun Department of Gastroenterology and Hepatology Chonnam National University Hospital and College of MedicineGwangju 61469South Korea Department of Gastroenterology and Hepatology Hwasun Chonnam National University Hospital and College of MedicineHwasun 58128South Korea Department of Surgery Chonnam National University Hospital and College of MedicineGwangju 61469South Korea Department of Surgery Hwasun Chonnam National University Hospital and College of MedicineHwasun 58128South Korea Department of Internal Medicine Mokpo Hankook HospitalMokpo 58643South Korea

BACKGROUND Surgical resection is one of the most widely used modalities for the treatment of hepatocellular carcinoma(HCC).Early extrahepatic recurrence(EHR)of HCC after surgical resection is considered to be closely associated with poor ***,data regarding risk factors and survival outcomes of early EHR after surgical resection remain *** To investigate the clinical features and risk factors of early EHR and elucidate its association with survival *** From January 2004 to December 2019,we enrolled treatment-naïve patients who were≥18 years and underwent surgical resection for HCC in two tertiary academic *** excluding patients with tumor types other than HCC and/or ineligible data,this retrospective study finally included 779 *** resection of HCC was performed according to the physicians’decisions and the EHR was diagnosed based on contrast-enhanced computed tomography or magnetic resonance imaging,and pathologic confirmation was performed in selected *** Cox regression analysis was performed to identify the variables associated with *** Early EHR within 2 years after surgery was diagnosed in 9.5%of patients during a median followup period of 4.4 *** recurrence-free survival period was 5.2 mo,and the median time to EHR was 8.8 mo in patients with early *** 52.7%of patients with early EHR,EHR occurred as the first recurrence of HCC after surgical *** multivariate analysis,serum albumin100 U/L,surgical margin involvement,venous and/or lymphatic involvement,satellite nodules,tumor necrosis detected by pathology,tumor size≥7 cm,and macrovascular invasion were determined as risk factors associated with early *** sub-categorizing the patients according to the number of risk factors,the rates of both EHR and survival showed a significant correlation with the risk of early ***,multivariate analysis revealed that early E

关键词： Early extrahepatic recurrence Hepatocellular carcinoma Prognosis Surgery Survival

Facile synthesis of fully ordered L10-FePt nanoparticles with controlled Pt-shell thicknesses for electrocatalysis

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Nano Research 2017年第8期10卷 2866-2880页

作者： Yonghoon Hong hee Jin Kim Daehee Yang Gaehang Lee Ki Min Nam Myung-Hwa Jung Young-Min Kim Sang-II Choi Won seok Seo Department of Chemistry Sogang University Seou104107 Republic of Korea Department of Chemistry and Green-Nano Materials Research Center Kyungpook National University Daegu 41566 Repubfic of Korea Korea Basic Science Institute and University of Science and Technology Daejeon 34133 Republic of Korea Department of Chemistry Mokpo National University Jeonnam 58554 Republic of Korea Department of Physics Sogang University Seoul 04107 Republic of Korea Center for Integrated Nanostructure Physics Institute for Basic Science (IBS) Suwon 16419 Repubfic of Korea Department of Energy Science Sungkyunkwan University (SKKU) Suwon 16419 Republic of Korea

We report a simple one-step approach for the synthesis of -4 nm uniform and fully L10-ordered face-centered tetragonal （fct） FePt nanoparticles （NPs） embedded in -60 nm MCM-41 （fct-FePt NPs@MCM-41）. We controlled the Pt-shell thickness of the fct-FePt NPs by treating the fct-FePt NPs@MCM-41 with acetic acid （HOAc） or hydrochloric acid （HC1） under sonicafion, thereby etching the surface Fe atoms of the NPs. The fct-FePt NPs deposited onto the carbon support （fct-FePt NP/C） were prepared by mixing the fct-FePt NPs@MCM-41 with carbon and subsequently removing the MCM-41 using NaOH. We also developed a facile method to synthesize acid-treated fct-FePt NP/C by using a HF solution for simultaneous surface-Fe etching and MCM-41 removal. We studied the effects of both surface-Fe etching and Pt-shell thickness on the electrocatalytic properties of fct-FePt NPs for the methanol oxidation reaction （MOR）. Compared with the non-treated fct-FePt NP/C catalyst, the HOAc-treated and HCl-treated catalysts exhibit up to 34% larger electrochemically active surface areas （ECASAs）; in addition, the HCl-treated fct-FePt NP （with -1.0 nm Pt shell）/C catalyst exhibits the highest specific activity. The HF-treated fct-FePt NP/C exhibits an ECASA almost 2 times larger than those of the other acid-treated fct-FePt NP/C catalysts and shows the highest mass activity （1,435 mA·mgPt^-1, 2.3 times higher than that of the commercial Pt/C catalyst） and stability among the catalysts tested. Our findings demonstrate that the surface-Fe etching for the generation of the Pt shell on fct-FePt NPs and the Pt-shell thickness can be factors for optimizing the electrocatalysis of the MOR.

关键词： FePt face centered tetragonal bimetallic methanol oxidation reaction electrocatalysts

Shape-controlled Pt nanocubes directly grown on carbon supports and their electrocatalytic activity toward methanol oxidation

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Science Bulletin 2017年第13期62卷 943-949页

作者： hee Jin Kim Bibi Ruqia Mi Sung Kang Su Bin Lim Ran Choi Ki Min Nam Won seok Seo Gaehang Lee Sang-Il Choi Department of Chemistry and Green-Nano Materials Research Center Kyungpook National University Department of Chemistry KAIST Department of Chemistry Mokpo National University Department of Chemistry Sogang University Korea Basic Science Institute(KBSI) and University of Science and Technology

Synthesis of shape-controlled Pt nanocrystals is substantial and important for enhancing chemical and electrochemical ***,the removal of capping agents,shape-controlling chemicals,on Pt surfaces is essential prior to conducting the catalytic *** we report a facile one-pot synthesis of Pt nanocubes directly grown on carbon supports(Pt nanocubes/C) with modulating the kinetic reaction factors for shaping the nanocrystals,but without adding any capping agents for preserving the clean Pt ***-dispersed Pt nanocubes/C shows enhanced activity and long-term stability toward methanol oxidation reaction compared to the commercial Pt/C catalyst.

关键词： Platinum Nanocube Shape-control Kinetic product Methanol oxidation

Adaptive Electrospinning System Based on Reinforcement Learning for Uniform‑Thickness Nanofiber Air Filters

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Advanced Fiber Materials 2023年第2期5卷 617-631页

作者： seok Hyeon Hwang Jin Yeong Song Hyun Il Ryu Jae hee Oh Seungwook Lee Donggeun Lee Dong Yong Park Sang Min Park School of Mechanical Engineering Pusan National University63‑2 Busan University‑roGeumjeong‑guBusan 46241South Korea Smart Manufacturing Technology R&D Group Korea Institute of Industrial Technology320 Techno Sunhwan‑roYuga‑eupDalseong‑gunDaegu 42994Republic of Korea

Electrospinning is a simple and versatile method to produce nanofiber ***,owing to bending instability that occurs during the electrospinning process,electrospinning has frequently produced a non-uniform-thickness nanofiber filter,which deteriorates its air ***,an adaptive electrospinning system based on reinforcement learning(E-RL)was developed to produce uniform-thickness nanofiber *** E-RL accomplished a real-time thickness measurement of an electrospun nanofiber filter by measuring the transmitted light through the nanofiber filter using a camera placed at the bottom of the collector and converting it into thickness using the Beer–Lambert *** on the measured thickness,the E-RL detected the non-uniformity of the nanofiber filter thickness and manipulated the movable collector to alleviate the non-uniformity of the thickness by a pre-trained reinforcement learning(RL)*** the training of the RL algo-rithm,the nanofiber production simulation software based on the empirical model of the deposition of the nanofiber filter was developed,and the training process of the RL algorithm was repeated until the optimal policy was *** the training process with the simulation software,the trained model was transferred to the adaptive electrospinning *** the movement of the collector under the optimal strategy of RL algorithm,the non-uniformity of such nanofiber filters was significantly reduced by approximately five times in standard deviation and error for both simulation and *** finding has great potential in improving the reliability of electrospinning process and nanofiber filters used in research and industrial fields such as environment,energy,and biomedicine.

关键词： Electrospinning Nanofiber filter Uniform thickness Reinforcement learning Deep Q-network