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Science China Materials 2022年第4期65卷 1028-1033页

作者： Junsu Ha Junseop lim Jun Yeob lee School of Chemical Engineering Sungkyunkwan University2066Seobu-roJangan-guSuwon-siGyeonggi-do16419Republic of Korea

An electron-transport-type host was synthesized using a benzo[4,5]furo[3,2-d]pyrimidine(BFP)core to develop a high triplet energy *** host was designed to have both the tetraphenylsilyl blocking group and the hole-transport-type carbazole *** the device application,the host was used as an electron-transport-type host mixed with a hole-transport-type 3,3'-di(9H-carbazol-9-yl)-1,1†-biphenyl(mCBP)host in the blue phosphorescent organic light-emitting diodes(PhO-LEDs)doped with a[[5-(1,1-dimethylethyl)-3-phenyl-1H-imidazo[4,5-b]pyrazin-1-yl-2(3H)-ylidene]-1,2-phenylene]bis-[[6-(1,1-dimethylethyl)-3-phenyl-1H-imidazo[4,5-b]pyrazin-1-yl-2(3H)-ylidene]-1,2-phenylene]iridium(Ir(cb)3)blue *** a result,the mCBP:CzBFPmSi mixed host showed high external quantum efficiency over 20%at 1000 cd m^(−2) and low efficiency roll-off in the blue PhOLEDs.

关键词： blue device host efficiency lifetime

A silane-based host material with improved electron transport properties for phosphorescent OLEDs with high efficiency and low efficiency roll-off

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Science China Materials 2023年第5期66卷 1997-2003页

作者： Jinho Park Junseop lim Jun Yeob lee School of Chemical Engineering Sungkyunkwan University 2066Seobu-roJangan-guSuwon-siGyeonggi-do16419Republic of Korea

A dibenzosilole-based host material was designed and *** host material,9,9'-(5,5-diphenyl-5H-dibenzo[b,d]silole-2,8-diyl)bis(9H-carbazole)(SSiCz),was designed to enhance the electron transport properties and rigidity by coupling two phenyl units of the tetraphenyl silane of a strong hole transport type bis(4-(9Hcarbazol-9-yl)phenyl)diphenylsilane *** device efficiency roll-off was improved considerably by balancing the carriers in the phosphorescent organic light-emitting diodes(PhOLEDs),and the driving voltage at high luminance was *** red and green PhOLEDs exhibited high external quantum efficiencies(EQEs)of 23.8%and 24.9%,respectively,and a relieved efficiency *** addition,S-SiCz was used as an electron transport type host with a hole transport type3,3'-di(9H-carbazol-9-yl)-1,1'-biphenyl *** maximum EQEs of the red and green PhOLEDs using the mixed host were 26.0%and 25.5%,respectively,and EQE roll-off values were 18%and 6%,***,the planarization design strategy of the host is effective for better device performance.

关键词： OLEDs host material silane bipolar phosphorescent OLEDs

The Effect of Fabrication Conditions for GDC Buffer Layer on Electrochemical Performance of Solid Oxide Fuel Cells

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Nano-Micro Letters 2013年第3期5卷 151-158页

作者： Jung-Hoon Song Myung Geun Jung hye Won Park Hyung-Tae lim Fuel Cell Project Research Institute of Industrial Science and Technology (RIST) School of Nano & Advanced Materials Engineering Changwon National University

A Gd-doped ceria（GDC） buffer layer is required between a conventional yttria-stabilized zirconia（YSZ） electrolyte and a La-Sr-Co-Fe-O3（LSCF） cathode to prevent their chemical reaction. In this study,the effect of varying the conditions for fabricating the GDC buffer layer, such as sintering temperature and amount of sintering aid, on the solid oxide fuel cell（SOFC） performance was investigated. A finer GDC powder（i.e., ultra-high surface area）, a higher sintering temperature（1290℃）, and a larger amount of sintering aid（12%） resulted in improved densification of the buffer layer; however, the electrochemical performance of an anode-supported cell containing this GDC buffer layer was poor. These conflicting results are attributed to the formation of（Zr, Ce）O2 and/or excess cobalt grain boundaries（GBs） at higher sintering temperatures with a large amount of sintering aid（i.e., cobalt oxide）. A cell comprising of a cobalt-free GDC buffer layer, which was fabricated using a low-temperature process, had lower cell resistance and higher stability. The results indicate that electrochemical performance and stability of SOFCs strongly depend on fabrication conditions for the GDC buffer layer.

关键词： Solid oxide fuel cell(SOFC) Gd-doped ceria Sintering aid Sol-gel spin coating

Feasibility Study of R134a/R404a Cascade Heat Pump Cycle in Heat Pump Dryers with Electrical Heaters at Low Temperatures

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Journal of Thermal Science 2015年第5期24卷 463-467页

作者： Ji Woo Jeong Young lim lee Dept. of Mechanical Engineering Kongju National University Dept. of Mechanical and Automotive Engineering Kongju National University

Heat pump cycles have been widely applied to dryers for their high efficiency. However, low–efficiency electrical heaters are often used during early drying stage for frozen foods or winter since a standard heat pump cycle cannot operate at low temperature. This study introduced cascade heat pumps replacing electrical heaters to improve dryer performance at low temperatures. Experiments were performed to examine changes in performance of the cascade heat pump dryers in relation to ambient temperature, low-stage cycle mass flow rate, and high-stage cycle mass flow rate. The results showed a significant improvement in low-temperature dryer performance with the introduction of cascade heat pump cycles.

关键词： Cascade cycle R134a/R404a Heat pump dryer COP Energy efficiency

Single-step Preparation of Nano-homogeneous NiO/YSZ Composite Anode for Solid Oxide Fuel Cells

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Nano-Micro Letters 2013年第2期5卷 111-116页

作者： Jung-Hoon Song Mi Young Park hye Won Park Hyung-Tae lim Research Institute of Industrial Science and Technology (RIST) Fuel Cell Project Changwon National University School of Nano & Advanced Materials Engineering

Homogeneous co-precipitation and hydrothermal treatment were used to prepare nano- and highly dispersed Ni O/YSZ(yttria-stabilized zirconia) composite powders. Composite powders of size less than 100 nm were successfully prepared. This process did not require separate sintering of the YSZ and Ni O to be used as the raw materials for solid oxide fuel cells. The performance of a cell fabricated using the new powders(*** density ~0.87 W/cm^2) was higher than that of a cell fabricated using conventional powders(max. power density ~0.73 W/cm^2). Co-precipitation and hydrothermal treatment proved to be very effective processes for reducing cell production costs as well as improving cell performance.

关键词： Fuel cells Powder processing Electrochemistry Hydrothermal process NiO/YSZ composite anode

Changes of the Flowering Time of Trees in Spring by Climate Change in Seoul, South Korea

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Phyton-International Journal of Experimental Botany 2020年第4期89卷 1019-1033页

作者： hyewon Kim Chanwoo Park Jong Hwan lim hye Woo Shin Interdisciplinary Program of EcoCreative The Graduate SchoolEwha Womans UniversitySeoul03760Korea Forest Ecology and Climate Change Division National Institute of Forest ScienceSeoul02455Korea Research Institute of Ecoscience Ewha Womans UniversitySeoul03760Korea

Flowering onset has attracted much attention in ecological research as an important indicator of climate ***,warmer temperatures advance flowering *** effect of climate warming on flowering onset is more pronounced in spring because the difference between atmospheric and water temperatures creates more rapid convection than in other *** analyzed the correlation between 73 species of spring woody plants in Hongneung Arboretum in Seoul,South Korea and the spring minimum temperature and average precipitation over the past 50 years(1968–2018).The spring minimum temperature and average precipitation have increased over the past 50 years,resulting in the advance of the first flowing date(FFD)in all 73 species by 8.5 days on average.A comparison of FFD changes over time by dividing the survey period into three time periods confirmed the advance of the FFD in 50 species(68%of investigated species)by 11.1 days on average in both Period 2(1999–2008)and Period 3(2009–2018)relative to Period 1(1968–1975).Additionally,a delay of the FFD by 3.2 days on average was observed in 8 *** FFD of Lonicera chrysantha(Caprifoliaceae)advanced by over 40 days and was highly correlated with the increased spring minimum *** of the sensitivity of plant responses to climate change revealed that a temperature rise of 1℃ was associated with an FFD advance of 1.2 days in all *** species that was most sensitive to temperature change was Spiraea pubescens ***(Rosaceae),whose FFD advanced by 4.7 days per 1℃ temperature *** increase in precipitation by 1 mm was found to result in a 0.1-day advance of the FFD of all *** tomentosa(Rosa-ceae)was the most sensitive species,that advanced by 2.6 days for each 1 mm increase in ***,for all species,the FFD was more sensitive to the change in temperature than in *** that the current greenhouse gas(GHGs)emission levels or atmospheric CO_(2) conc

关键词： Phenology first flowering date climate change

Prediction models of hepatocellular carcinoma development in chronic hepatitis B patients

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World Journal of Gastroenterology 2016年第37期22卷 8314-8321页

作者： hye Won lee Sang Hoon Ahn Department of Internal Medicine Yonsei University College of Medicine Seoul 03722 South Korea Institute of Gastroenterology Yonsei University College of Medicine Seoul 03722 South Korea Liver Cirrhosis Clinical Research Center Seoul 03722 South Korea Brain Korea 21 Project for Medical Science Seoul 03722 South Korea

Chronic hepatitis B virus(HBV) infection is a major cause of cirrhosis and hepatocellular carcinoma(HCC). Applying the same strategies for antiviral therapy and HCC surveillance to all chronic hepatitis B(CHB) patients would be a burden worldwide. To properly manage CHB patients, it is necessary to identify and classify the risk for HCC development in such patients. Several HCC risk scores based on risk factors such as cirrhosis, age, male gender, and high viral load have been used, and have negative predictive values of ≥ 95%. Most of these have been derived from, and internally validated in, treatment-na?ve Asian CHB patients. Herein, we summarized various HCC prediction models, including IPM(Individual Prediction Model), CU-HCC(Chinese University-HCC), GAG-HCC(Guide with Age, Gender, HBV DNA, Core Promoter Mutations and Cirrhosis-HCC), NGM-HCC(NomogramHCC), REACH-B(Risk Estimation for Hepatocellular Carcinoma in Chronic Hepatitis B), and Page-B score. To develop a noninvasive test of liver fibrosis, we also introduced a new scoring system that uses liver stiffness values from transient elastography, including an LSM(Liver Stiffness Measurement)-based model, LSM-HCC, and mR EACH-B(modified REACH-B).

关键词： Chronic hepatitis B Hepatocellular carcinoma Development Prediction models

Chronic liver inflammation:Clinical implications beyond alcoholic liver disease

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World Journal of Gastroenterology 2014年第9期20卷 2168-2175页

作者： Byoung-Jin Park Yong-Jae lee hye-Ree lee Department of Family Medicine CHA University School of Medicine Seoul 135-720 South Korea Department of Family Medicine Yonsei University College of Medicine Seoul 135-720 South Korea

Chronic alcohol exposure can lead to alcoholic liver disease, including hepatitis, cirrhosis and hepatocellular carcinoma, and chronic inflammation can simultaneously cause systemic medical illness. Recent evidence suggests that alcoholic liver disease is a predictor for liver-related diseases, cardiovascular disease, immunologic disease, and bone disease. Chronic inflammation in alcoholic liver disease is mediated by a direct inflammatory cascade from the alcohol detoxification process and an indirect inflammatory cascade in response to gut microflora-derived lipopolysaccharides (LPS). The pathophysiology of alcoholic liver disease and its related systemic illness is characterized by oxidative stress, activation of the immune cascade, and gut-liver interactions. Integrative therapeutic strategies for alcoholic liver disease include abstaining from alcohol consumption; general anti-inflammatories such as glucocorticoid, pentoxifylline, and tumour necrosis factor-α antagonist; antioxidants such as N- acetylcysteine; gut microflora and LPS modulators such as rifaximin and/or probiotics. This review focuses on the impact of chronic liver inflammation on systemic health problems and several potential therapeutic targets.

关键词： Alcoholic liver disease Oxidative stress Cardiovascular disease Immunologic disease Bone disease

Selective conversion of N_(2) to NH_(3) on highly dispersed RuO_(2) using amphiphilic ionic liquid-anchored fibrous carbon structure

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Journal of Energy Chemistry 2022年第4期31卷 474-482页

作者： Kahyun Ham Muhammad Salman Sunki Chung Minjun Choi HyungKuk Ju hye Jin lee Jaeyoung lee School of Earth Sciences and Environmental Engineering Gwangju Institute of Science and Technology(GIST)123 Cheomdangwagi-RoGwangju 61005South Korea International Future Research Center of Chemical Energy Storage and Conversion Processes GIST123 Cheomdangwagi-RoGwangju 61005South Korea Ertl Center for Electrochemical and Catalysis GIST123 Cheomdangwagi-RoGwangju 61005South Korea Department of Chemistry and Green-Nano Materials Research Center Kyungpook National University80 Daehak-RoDaegu-city 41566South Korea Hydrogen Research Department Korea Institute of Energy Research152 Gajeong-RoYuseong-guDaejeon 34129South Korea

Ammonia (NH_(3)) plays a key role in the agricultural fertilizer and commodity chemical industries and is useful for exploring hydrogen storage *** electrochemical nitrogen reduction reaction (NRR) is receiving attention as an environmentally sustainable NH_(3) synthesis replacement for the traditional Haber–Bosch process owing to its near ambient reaction conditions (limidazolium hydroxide[HOBIM]OH) for a highly dispersed ruthenium oxide electrocatalyst to achieve a biased *** observed uniform distribution of RuO_(2) on the carbon fiber and increase in the surface area for N_(2) adsorption by limiting proton access can be attributed to the presence of imidazolium ***,extensive N_(2) adsorption contributes to enhanced NRR selectivity with an NH_(3) yield of 3.0×10^(-10)mol cm^(-2)s^(-1)(91.8μg h^(-1)mg^(-1)) and a faradaic efficiency of 2.2%at-0.20 V_(RHE).We expect our observations to provide new insights into the design of effective electrode structures for electrochemical NH;synthesis.

关键词： Ammonia synthesis Nitrogen reduction reaction Imidazolium-based ionic liquid Ruthenium oxide

Percutaneous paraumbilical embolization as an unconventional and successful treatment for bleeding jejunal varices

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World Journal of Gastroenterology 2009年第30期15卷 3823-3826页

作者： lee-Guan lim Yin-Mei lee Lenny Tan Stephen Chang Seng-Gee lim Department of Gastroenterology and Hepatology National University HospitalSingapore 119074Singapore Department of Diagnostic Radiology National University HospitalSingapore 119074Singapore Department of Surgery National University HospitalSingapore 119074Singapore

A 48-year-old Indian male with alcoholic liver cirrhosis was admitted after being found unresponsive. He was hypotensive and had hematochezia. Esophagogastroduodenoscopy (EGD) showed small esophageal varices and a clean-based duodenal ulcer. He continued to have hematochezia and anemia despite blood transfusions. Colonoscopy was normal. Repeat EGD did not reveal any source of recent bleed. Twelve days after admission, his hematochezia ceased. He refused further investigation and was discharged two days later. He presented one week after discharge with hematochezia. EGD showed non-bleeding Grade 1 esophageal varices and a clean-based duodenal ulcer. Colonoscopy was normal. Abdominal computed tomography (CT) showed liver cirrhosis with mild ascites, paraumbilical varices, and splenomegaly. He had multiple episodes of hematochezia, requiring repeated blood transfusions. Capsule endoscopy identified the bleeding site in the jejunum. Concurrently, CT angiography showed paraumbilical varices inseparable from a loop of small bowel, which had herniated through an umbilical hernia. The lumen of this loop of small bowel opacified in the delayed phase, which suggested variceal bleeding into the small bowel. Portal vein thrombosis was present. As he had severe coagulopathy and extensive paraumbilical varices, surgery was of high risk. He was not suitable for transjugular intrahepatic porto-systemic shunt as he had portal vein thrombosis. Percutaneous paraumbilical embolization via caput medusa was performed on day 9 of hospitalization. Following the embolization, the hematochezia stopped. However, he defaulted subsequent follow-up.

关键词： Embolization Jejunal varices Obscurebleed Capsule endoscopy Angiography