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Biomass-derived bifunctional electrocatalysts for oxygen reduction and evolution reaction: A review

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Journal of Energy Chemistry 2022年第2期31卷 149-172页

作者： Satpal Singh Sekhon Jaeyoung Lee Jin-soo Park Future Environment and Energy Research Institute Sangmyung UniversityCheonan 31066Republic of Korea Department of Physics Guru Nanak Dev UniversityAmritsar 143005India Ertl Center for Electrochemistry and Catalysis Gwangju Institute of Science and Technology123 Cheomdangwagi-roBuk-guGwangju 61005Republic of Korea Department of Green Chemical Engineering College of EngineeringSangmyung UniversityCheonan 31066Republic of Korea

Oxygen electrode catalysts are important as inter-conversion of O_(2) and H_(2)O is crucial for energy ***,the sluggish kinetics of oxygen reduction and evolution reactions(ORR and OER)are a hindrance to their scalable production,whereas scarce and costly Pt and Ir/Ru-based catalysts with the highest electrocatalytic activity are commercially *** good ORR catalysts are not always efficient for OER and vice versa,so bifunctional catalysts on which OER and ORR occurs on the same electrode are very *** catalysts based on heteroatom-doped carbon nanomaterials,though showed good electrocatalytic activity yet their high cost and complex synthesis is not viable for scalable *** overcome these drawbacks,biomass-derived heteroatom-doped porous carbons have recently emerged as low-cost,earth-abundant,renewable and sustainable environment-friendly materials for bifunctional oxygen *** tunable morphology,mesoporous structure and high concentration of catalytic active sites of these materials due to heteroatom(N)-doping could further enhance their ORR and OER activity,along with tolerance to methanol crossover and good ***,biomassderived heteroatom-doped porous carbons with large surface area,rich edge defects,numerous micropores and thin 2 D nanoarchitecture could be suitable as efficient bifunctional oxygen *** the present article,synthesis,N-doping,ORR/OER mechanism and electrocatalytic performance of biomassderived bifunctional catalysts has been *** selected biomass(chitin,eggs,euonymus japonicas,tobacco,lysine and plant residue)except wood,act as both C and N precursor,resulting in N selfdoping of porous carbons that avoids the use of toxic chemicals,thus making the synthesis a facile and environment-friendly green *** synthetic strategy could be further optimized to develop future biomass-based N self-doped porous carbons as metal-free high performance bifunctional oxy

关键词： Bifunctional catalysts Biomass ORR OER N-doping Porous carbons

Integration of earth-abundant cocatalysts for high-performance photoelectrochemical energy conversion

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Journal of Energy Chemistry 2024年第1期88卷 336-355,I0008页

作者： Joonhee Ma Sang Hyun Ahn soo Young Kim Department of Materials Science and Engineering Korea UniversitySeoul 02841Republic of Korea School of Chemical Engineering and Materials Science Chung-Ang University84 Heukseok-roDongjak-guSeoul 06974Republic of Korea

Photoelectrochemical(PEC)energy conversion has emerged as a promising and efficient approach to sustainable energy harvesting and *** utilizing semiconductor photoelectrodes,PEC devices can harness solar energy and drive electrochemical reactions such as water splitting or carbon dioxide(CO_(2))reduction to generate clean fuels and value-added ***,PEC energy conversion faces several challenges such as high overpotential,sluggish reaction kinetics,charge carrier recombination,and stability issues,which limit its practical ***,significant research has been conducted to improve the overall conversion efficiency of PEC *** particularly promising approach is the use of cocatalysts,which involves introducing specific cocatalysts onto the photoelectrode surface to promote charge separation,improve reaction kinetics,and reduce the overpotential,thereby enhancing the overall performance of PEC energy *** review provides a comprehensive overview of the recent developments in the earth-abundant cocatalysts for PEC water splitting and CO_(2) *** main earth-abundant catalysts for the PEC water splitting include transition-metal dichalcogenide(TMD)-based materials,metal phosphides/carbides,and metal oxides/***,PEC-CO_(2)RR was divided into C_(1) and C_(2+)based on the final product since various products could be produced,focusing on diverse earth-abundant materials-based *** addition,we provide and highlight key advancements achieved in the very recent reports on novel PEC system design engineering with ***,the current problems associated with PEC systems are discussed along with a suggested direction to overcome these obstacles.

关键词： Solar energy Photo-electrochemical Water splitting CO_(2)reduction Cocatalysts

Enumerating Abelian Typical Cube-Free Fold Coverings of a Circulant Graph

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Algebra Colloquium 2020年第1期27卷 137-148页

作者： Young soo Kwon Jaeun Lee Department of Mathematics Yeungnam UniversityKyongsan712-749Korea

Enumerating the isomorphism or equivalence classes of several types of graph coverings is one of the central research topics in enumerative topological graph theory.A covering projection p from a Cayley graph Cay(Г,X)onto another Cayley graph Cay(Q,y)is called typical if the function p:Г→Q on the vertex sets is a group epimorphism.A typical covering is called abelian(or circulant,respectively)if its covering graph is a Cayley graph on an abelism(or a cyclic,respectively)***,the equivalence classes of connected abelian typical prime-fold coverings of a circulant graph are *** a continuation of this work,we enumerate the equivalence classes of connected abelian typical cube-free fold coverings of a circulant graph.

关键词： graph covering enumeration voltage assignment circulant graph

High tibial osteotomy with human umbilical cord blood-derived mesenchymal stem cells implantation for knee cartilage regeneration

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World Journal of Stem Cells 2020年第6期12卷 514-526页

作者： Jun-Seob Song Ki-Taek Hong Chae-Gwan kong Na-Min Kim Jae-Yub Jung Han-soo Park Young Ju Kim Ki Bong Chang Seok Jung Kim Department of Orthopedic Surgery Gangnam JS HospitalSeoul 06053South Korea Department of Orthopedic Surgery College of MedicineThe Catholic University of KoreaUijeongbu-si 11765South Korea Department of Nursing Education&Administration Uijeongbu St.Mary’s HospitalThe Catholic University of KoreaUijeongbu-si 11765South Korea

BACKGROUND High tibial osteotomy(HTO)is a well-established method for the treatment of medial compartment osteoarthritis of the knee with varus ***,HTO alone cannot adequately repair the arthritic joint,necessitating cartilage regeneration *** regeneration procedures with concomitant HTO are used to improve the clinical outcome in patients with varus *** To evaluate cartilage regeneration after implantation of allogenic human umbilical cord blood-derived mesenchymal stem cells(hUCB-MSCs)with concomitant *** Data for patients who underwent implantation of hUCB-MSCs with concomitant HTO were *** patients included in this study were over 40 years old,had a varus deformity of more than 5°,and a full-thickness International Cartilage Repair Society(ICRS)grade IV articular cartilage lesion of more than 4 cm2 in the medial compartment of the *** patients underwent second-look arthroscopy during hardware *** regeneration was evaluated macroscopically using the ICRS grading system in second-look *** also assessed the effects of patient characteristics,such as trochlear lesions,age,and lesion size,using patient medical *** A total of 125 patients were included in the study,with an average age of 58.3±6.8 years(range:43-74 years old);95(76%)were female and 30(24%)were *** average hip-knee-ankle(HKA)angle for measuring varus deformity was 7.6°±2.4°(range:5.0-14.2°).In second-look arthroscopy,the status of medial femoral condyle(MFC)cartilage was as follows:73(58.4%)patients with ICRS grade I,37(29.6%)with ICRS grade II,and 15(12%)with ICRS grade *** patients were staged with ICRS grade ***,the scores[except International Knee Documentation Committee(IKDC)at 1 year]of the ICRS grade I group improved more significantly than those of the ICRS grade II and III *** Implantation of hUCB-MSCs with concomitant HTO is an effective treatment for patients wit

关键词： Allogeneic Human umbilical cord blood-derived mesenchymal stem cells Cartilage regeneration High tibial osteotomy Osteoarthritic knees Arthroscopy

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Journal of Central South University 2013年第9期20卷 2440-2446页

作者： LEE Sang-hyuk SHIN Seung-soo Department of Electrical and Electronic Engineering Xi'an Jiaotong-Liverpool University Department of Information Security Tongmyong University

Similarity measure design on non-overlapped data was carried out and compared with the case of overlapped *** feature of similarity on overlapped data to non-overlapped data was provided by *** the artificial data illustration,it was proved that the conventional similarity measure was not proper to calculate the similarity measure of the non-overlapped *** overcome the unbalance problem,similarity measure on non-overlapped data was obtained by considering neighbor ***,different approaches to design similarity measure were proposed and proved by consideration of neighbor *** the example of artificial data,similarity measure calculation was carried *** measure extension to intuitionistic fuzzy sets(IFSs)containing uncertainty named hesitance was also followed.

关键词： similarity measure overlapped data non-overlapped data intuitionistic data

Local Meteorological and Synoptic Characteristics of Fogs Formed over Incheon International Airport in the West Coast of Korea

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Advances in Atmospheric Sciences 2010年第4期27卷 761-776页

作者： Chang Ki KIM Seong soo YUM Department of Atmospheric Sciences Yonsei University 134 Shinchon-dong Seodaemun-gu Seoul 120-749 Korea

Fogs observed over Incheon international airport （IIA） in the west coast of Korea from January 2002 to August 2006 are classified into categories of coastal fog, cold sea fog, and warm sea fog based on the areal extent of the fogs and the difference between the air temperature （T ） and the SST, i.e., cold sea fog if TSST = T -SST 〉 0~0C and warm sea fog if TSST 〈 0~0C. The numbers of coastal, cold, and warm sea fog cases are 64, 26, and 9. Coastal fogs form most frequently in winter, while cold sea fogs occur mostly in summer and warm sea fogs are observed from January to May but not in November and December. On average the air gets colder by 1.6~0C during the three hours leading up to the coastal fog formation, and an additional cooling of 1.1~0C occurs during the fog. The change in the dew point temperature （T_d） is minimal except during the fog （0.6~0C）. Decreases in T for the cold and warm sea fogs are relatively smaller. The average Td is higher than SST during the cold sea fog periods but this T_d is more than 4~0C higher than that for the corresponding non-fog days, suggesting that cold sea fogs be formed by the cooling of already humid air （i.e., T_d〉SST）. Increases of T_d are significant during the warm sea fog periods （1.4~0C）, implying that effcient moisture supply is essential to warm sea fog formation. Four major synoptic patterns are identified in association with the observed fogs. The most frequent is a north Pacific high that accounts for 38% of cases. Surface or upper inversions are present in 77%, 69%, and 81% of the fog periods for coastal, cold, and warm sea fogs, respectively.

关键词： costal fogs sea fogs west coast of Korea meteorological and synoptic characteristics

Numerical Study of Air Chamber for Oscillating Water Column Wave Energy Convertor

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China Ocean Engineering 2011年第1期25卷 169-178页

作者：刘臻 HYUN Beom-soo HONG Keyyong Shandong Key Laboratory of Ocean Engineering Ocean University of China College of Ocean Science and Technology Korea Maritime University Maritime & Ocean Engineering Research Institute Korea Ocean Research & Development Institute

Oscillating Water Column （OWC） wave energy converting system is one of the most widely used facilities all over the world. The air chamber is utilized to convert the wave energy into the pneumatic energy. The numerical wave tank based on the two-phase VOF model is established in the present study toinvestigate the operating performance of OWC air chamber. The RANS equations, standard k-ε turbulence model and dynamic mesh technology are employed in the numerical model. The effects of incident wave conditions and shape parameters on the wave energy converting efficiency are studied and the capability of the present numerical wave tank on the corresponding engineering application is validated.

关键词： Oscillating water column numerical wave tank operating performance air chamber shape parameter

Wave Hindcast for the Neighbouring Seas of Korea Based on Loosely Coupled Wave-Tide-Surge Model

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China Ocean Engineering 2002年第2期17卷 165-181页

作者： CHOIByung-Ho EUMHyun-Min JEONSang-soo Department of Civil and Environmental Engineering Sungkyunkwan UniversityDepartment of Civil and Environmental EngineeringSungkyunkwan UniversityDepartment of Civil and Environmental EngineeringSungkyunkwan University Suwon 440-746KoreaSuwon 440-746KoreaSuwon 440-746Korea

A hindcast simulation of 75 typhoons and winter monsoons which affected the coastal areas of Korean Peninsula is performed by use of a third generation ocean wave prediction model, WAM-cycle 4 model, loosely coupled with a com-bined tide and surge model. Typhoon wind fields are derived from the planetary marine boundary layer model for effective neutral winds embedding the vortical storm wind from the parameterized Rankin vortex type model in the limited areas of the overall modeled region. The hindcasted results illustrate that significant wave heights (SWH) considering the wave-tide-surge coupled process are significantly different from the results via the decoupled case especially in the region of the estuaries of the Changjiang Estuary, The Hangzhou Bay, and the southwestern tip of Korean Peninsula. This extensive model simulation is the first attempt to investigate the strong wave-tide-surge interaction for the shallow depth area along the coasts of the Yellow Sea and the East China Sea Continental shelf.

关键词： wave hindcast mave-tide-surge process loosely coupled model significant wave height

Noncommutative Versions of the Singer-Wermer Conjecture with Linear Left θ-derivations

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Acta Mathematica Sinica,English Series 2008年第11期24卷 1891-1900页

作者： Yong soo JUNG Kyoo Hong PARK Department of Mathematics Sun Moon University Asan Chungnam 336-708 Korea Department of Mathematics Education Seowon University Cheongju Chungbuk 361-742 Korea

The noncommutative Singer-Wermer conjecture states that every linear （possibly unbounded） derivation on a （possibly noncommutative） Banach algebra maps into its Jacobson radical. This conjecture is still an open q... 详细信息

关键词： linear left θ-derivation linear θ-derivation Jacobson radical nil radical