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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： N.IQBAL J.choi S.F.SHAH c.LEE S.LEE Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyco_(z)O_(2)(x≥0.8)(NMc.p.rticles with poly(3,4-ethylenedioxythiophene)(pEDOT).The simulation results show that the coating of primary NMc.p.rticles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMc active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation Ni-rich LiNixMnyco_(z)O_(2)(x>0.8)(NMc)

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海啸后的皮肤病

世界核心医学期刊文摘（皮肤病学分册） 2006年第11期2卷 26-27页

作者： Lee S.H. choi c.p. Eun H.c. Kwon O.S. 党倩丽 Department of Dermatology Seoul National University College of Medicine 28Yongon-DongChongno-GuSeoul 110-744 South Korea

Background: On December 26, 2004, the biggest earthquake for 40 years, measuring 9.0 on the Richter scale, triggered a tsunami that pounded the coastal areas of South Asia and East Africa. The effects of the tsunami on skin conditions have not been evaluated. Objective: To determine the influence of the tsunami on skin conditions by evaluating the skin problems of patients presenting at hospitals after the tsunami. Methods: Between 5 and 25 January 2005, two dermatologists evaluated patients who complained of skin problems at an outpatient clinic and emergency room of a general hospital in Banda Aceh, Aceh province, Indonesia. Results: The total number of patients that presented during the study period was 235 (131 males and 104 females), and they had a total of 265 skin problems. In terms of age distribution, most subjects were in their fourth decade (23.0%), followed by the third (22.6%) and fifth decade (16.6%). The most prevalent skin problems were infections-infestations (32.5%), followed by eczemas (29.8%) and traumatic skin disorders (29.4%). In males, traumatic skin disorders were most common. The great majority of infection-infestation cases involved superficial fungal infections. contact dermatitis accounted for three-quarters of eczema cases, and mainly involved the arms (40.0%) and legs (27.1%). The majority of traumatic skin disorders were lacerations, punctures and penetrations, and the feet (44.7%) and hands (18.8%) were most frequently affected. conclusions: Unhygienic conditions, exposure to a hazardous environment and contact with various objects during and after the tsunami probably increased the prevalence of infections-infestations, traumatic skin disorders and contact dermatitis. To prevent these problems and associated secondary bacterial infections, health-related education and early medical management are required.

关键词：皮肤状况班达亚齐浅部真菌感染湿疹患者皮肤科医生医院患者继发性细菌感染综合医院年龄分布

correlation between hydration properties and electrochemical performances on Ln cation size effect in layered perovskite for protonic ceramic fuel cells

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Journal of Energy chemistry 2024年第1期88卷 1-9,I0001页

作者： Inhyeok cho Jiwon Yun Boseok Seong Junseok Kim Sun Hee choi Ho-Il Ji Sihyuk choi Department of Mechanical Engineering Kumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Department of Aeronautics Mechanical and Electronic Convergence EngineeringKumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea center for Energy Materials Research Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea center for Hydrogen and Fuel cell Research Clean Technology Research DivisionKorea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Department of Energy and Environmental Engineering University of Science and TechnologySeoul 02792Republic of Korea Nanomaterials Science and Engineering Korea University of Science and Technology(UST)KIST CampusSeoul 02792Republic of Korea

prBa_(0.5)Sr_(0.5)co_(1.5)Fe_(0.5)O_(5+δ)(prBScF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEc) electrode for protonic ceramic fuel cells(pcFcs). The chemical formula for pr BScF is AA'B_(2)O_(5+δ), with pr(A-site) and Ba/Sr(A'-site) alternately stacked along the c-axis. Due to these structural features, the bulk oxygen ion diffusivity is significantly enhanced through the disorder-free channels in the prO layer;thus, the A site cations(lanthanide ions) play a pivotal role in determining the overall electrochemical properties of layered perovskites. consequently, previous research has predominantly focused on the electrical properties and oxygen bulk/surface kinetics of Ln cation effects,whereas the hydration properties for pcFc systems remain unidentified. Here, we thoroughly examined the proton uptake behavior and thermodynamic.p.rameters for the hydration reaction to conclusively determine the changes in the electrochemical performances depending on LnBa_(0.5)Sr_(0.5)co_(1.5)Fe_(0.5)O_(5+δ)(LnBScF,Ln=pr, Nd, and Gd) cathodes. At 500 ℃, the quantitative proton concentration of prBScF was 2.04 mol% and progressively decreased as the Ln cation size decreased. Similarly, the Gibbs free energy indicated that less energy was required for the formation of protonic defects in the order of pr BScF cF cF. To elucidate the close relationship between hydration properties and electrochemical performances in LnBScF cathodes, pcFc single cell measurements and analysis of the distribution of relaxation time were further investigated.

关键词： protonic ceramic fuel cell cathode Triple ionic and electronic conductor Hydration property proton uptake Gibbs free energy

Rapid monitoring of indoor airborne influenza and coronavirus with high air flowrate electrostatic sampling and pcR analysis

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 73-85页

作者： Sanggwon An Sangsoo choi Hyeong Rae Kim Jungho Hwang School of Mechanical Engineering Yonsei UniversitySeoul 02876Republic of Korea Gas Metrology Group Korea Research Institute of Standards and Science(KRISS)Daejeon 34113Republic of Korea

The World Health Organization has raised concerns about the possibility of airborne transmission in enclosed and poorly ventilated ***,rapid monitoring of airborne viruses is necessary in multi-use facilities with dense ***,an electrostatic air sampler(250 L/min)was developed in this work to obtain indoor viral aerosol samples for analysis via the polymerase chain Reaction(pcR).Aerosol tests with H1N1 and HcoV-229E were performed to evaluate the sample collection *** analysis,along with another aerosol test,was conducted to evaluate the recovery of the virus particles collected by the *** laboratory tests,our electrostatic sampler obtained viral samples that were detectable by pcR under the simulated viral pandemic scenario(3000 RNA c.p.es per cubic meter of air)within 40 *** resulting cycle threshold(c)values were 35.07 and 37.1 for H1N1 and HcoV-229E,*** the performance evaluation in the laboratory,field tests were conducted in a university classroom from October 28 to December 2,*** A and HcoV-229E were detected in two air samples,and the corresponding c,values were 35.3 and *** pcR results are similar to those obtained from laboratory tests,considering the simulatedviralpandemic scenario.

关键词： Airborne virus Electrostatic sampler Rapid monitoring Indoor environment Field test

Anti-obesity effects of fucoidan from Sargassum thunbergii in adipocytes and high fat diet induced obese mice through inhibiting adipogenic specific transcription factor

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Food Science and Human Wellness 2024年第3期13卷 1608-1616页

作者： Hyo-Geun Lee H.H.A.c.K.Jayawardhana Fengqi Yang D.p.Nagahawaththa N.M.Liyanage Kyung-Mo Song Yun-Sang choi Seung-Hong Lee You-Jin Jeon Min-cheol Kang Department of Marine Life Sciences Jeju National UniversityJeju 63243Republic of Korea Marine Science Institute Jeju National UniversityJeju 63333Republic of Korea Research Group of Food processing Korea Food Research InstituteWanju 55365Republic of Korea Department of pharmoceutical Engineering Soonchunhyang UniversityAsan 31538Republic of Korea

The prevalence of obesity has increased and is a health concern *** to the concerns regarding synthetic anti-obesity treatments,nowadays natural products become a *** studies proved that there is a potential to use marine algae as anti-obesity ***,in this study,the lipid inhibitory effect of crude polysaccharide of amyloglucosidase-assisted hydrolysate from Sargassum thunbergii(STAc)and its fucoidan fractions(STAFs)on 3T3-L1 cells and high-fat diet(HFD)-induced obese mice were *** to the results,the STAF3,showed the highest xylose content and exhibited significant inhibitory effects on lipid accumulation by downregulating adipogenic and lipogenic.p.oteins in 3T3-L1 ***,oral supplementation with STAc significantly declined gain in body weight and fat weight,and serum lipid contents in an HFD-induced obesity mouse *** and chemical characterizations demonstrated that puritied STAF3 has consistent surface morphology and small particle size,with similar structural characteristics as commercial ***,these results indicate that STAc and purified STAF3 from Sargassum thunbergia is a potent source to develop as ananti-obesity agents or functional food products to counter obesity.

关键词： Sargassum thunbergii Fucoidan Anti-obesity Anti-steatosis

Enhancing BiVO_(4)photoanode performance by insertion of an epitaxial BiFeO_(3)ferroelectric layer

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Journal of Energy chemistry 2024年第2期89卷 71-78,I0003页

作者： Haejin Jang Yejoon Kim Hojoong choi Jiwoong Yang Yoonsung Jung Sungkyun choi Donghyeon Lee Ho Won Jang Sanghan Lee School of Materials Science and Engineering Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Republic of Korea

BiVO_(4)(BVO)is a promising material as the photoanode for use in photoelectrochemical ***,the high charge recombination and slow charge transfer of the BVO have been obstacles to achieving satisfactory photoelectrochemical *** address this,various modifications have been attempted,including the use of ferroelectric *** materials can form a permanent polarization within the layer,enhancing the separation and transport of photo-excited electron-hole *** this study,we propose a novel approach by depositing an epitaxial BiFeO_(3)(BFO)thin film underneath the BVO thin film(BVO/BFO)to harness the ferroelectric.p.operty of *** self-polarization of the inserted BFO thin film simultaneously functions as a buffer layer to enhance charge transport and a hole-blocking layer to reduce charge *** a result,the BVO/BFO photoanodes showed more than 3.5 times higher photocurrent density(0.65 mA cm^(-2))at 1.23 V_(RHE)under the illumination compared to the bare BVO photoanodes(0.18 m A cm^(-2)),which is consistent with the increase of the applied bias photon-to-current conversion efficiencies(ABpE)and the result of electrochemical impedance spectrosc.p.(EIS)*** results can be attributed to the self-polarization exhibited by the inserted BFO thin film,which promoted the charge separation and transfer efficiency of the BVO photoanodes.

关键词： photoelectrochemical photoanode BiVO_(4) Ferroelectric materials BiFeO_(3)

Modeling asymmetric fracture mechanics of Mg alloy wire in drawing process

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Journal of Magnesium and Alloys 2024年第5期12卷 2057-2069页

作者： Sunghoon choi Jongwon Shin Joung Sik Suh Dongchoul Kim Department of Mechanical Engineering Sogang UniversitySeoul04107Republic of Korea Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

In this study,a numerical analysis was conducted on the ductile fracture of a 2-mm diameter Mg-1Zn-0.5Mn-0.5Sr-0.1ca alloy wire during *** hexagonally close-packed crystal structure of Mg alloys causes asymmetric fracture behavior,especially in the compression *** aim of this study is to develop a comprehensive damage model for Mg alloy wire that accurately predicts ductile fracture,with a focus on the compression region.A novel experimental method was introduced to measure the ductile fracture of Mg alloy wires under different stress *** wire drawing process was simulated using the Generalized Incremental Stress-State dependent damage(GISSMO)Model and the Semi-Analytical Model for polymers(SAMp)*** damage model's prediction and the experimental results were found to be in excellent agreement,especially in determining crack *** analysis established a safe zone diagram for die angle and reduction ratio,and experimental validation confirmed the feasibility of this *** proposed damage model can provide a practical and reliable analysis for optimizing the drawing process of Mg alloy wire.

关键词： Mg alloy Wire drawing Finite element method Damage model Safe zone diagram

comparison of commercial silicon-based anode materials for the design of a high-energy lithium-ion battery

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Nano Research 2024年第6期17卷 5270-5277页

作者： Minhong choi Eunhan Lee Jaekyung Sung Namhyung Kim Minseong Ko Division of convergence Materials Engineering Pukyong National UniversityBusan 48547Republic of Korea Department of Materials Engineering and convergence Technology Gyeongsang National University501 Jinju-daeroJinju 52828Republic of Korea Department of Materials System Engineering Pukyong National UniversityBusan 48547Republic of Korea

Silicon(Si)is considered a potential alternative anode for next-generation Li-ion batteries owing to its high theoretical c.p.city and ***,the commercial use of Si anodes is hindered by their large volume expansion(~300%).Numerous efforts have been made to address this *** these efforts,Si-graphite co-utilization has attracted attention as a reasonable alternative for high-energy anodes.A comparative study of representative commercial Si-based materials,such as Si nanoparticles,Si suboxides,and Si−Graphite composites(SiGc),was conducted to characterize their overall performance in high-energy lithium-ion battery(LIB)design by incorporating conventional ***-Si was found to exhibit poor electrochemical performance,with severe volume expansion during *** suboxide provided excellent cycling stability in a full-cell evaluation with stable volume variation after 50 cycles,but had a large irreversible c.p.city and remarkable volume expansion during the first *** displayed a good initial coulombic efficiency and the lowest volume change in the first cycle owing to the uniformly distributed nano-Si layer on graphite;however,its long-term cycling stability was relatively *** complement each disadvantage of Si suboxide and SiGc,a new combination of these Si-based anodes was suggested and a reasonable improvement in overall battery performance was successfully achieved.

关键词： silicon-based anode high-energy comparison lithium ion battery blended electrode

Data driven computational design of stable oxygen evolution catalysts by DFT and machine learning:promising electrocatalysts

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Journal of Energy chemistry 2024年第4期91卷 645-655页

作者： Hwanyeol park Yunseok Kim Seulwon choi Ho Jun Kim Department of Display Materials Engineering Soonchunhyang UniversityAsanChung-nam 31538Republic of Korea Department of Electronic Materials Devicesand Equipment EngineeringSoonchunhyang Uni-versityAsanChungnam 31538Republic of Korea Department of Mechanical Engineering Hanyang University ERICA Campus55 Hanyangdaehak-roSangnok-guAnsanGyeonggi-do 15588Republic of Korea

The revolutionary development of machine learning(ML),data science,and analytics,coupled with its application in material science,stands as a significant milestone of the scientific community over the last *** active,stable,and cost-efficient catalysts is crucial for oxygen evolution reaction owing to the significance in a range of electrochemical energy co nversion *** this work,we have demonstrated an efficient approach of high-throughput screening to find stable transition metal oxides under acid condition for high-performance oxygen evolution reaction(OER)catalysts through density functional theory(DFT)calculation and a machine learning algorithm.A methodology utilizing both the Materials project database and DFT calculations was introduced to assess the acid stability under specific reaction *** upon this,OER catalytic activity of acid-stable materials was examined,highlighting potential OER catalysts that meet the required *** identified IrO_(2),Fe(SbO_(3))_(2),co(SbO_(3))_(2),Ni(SbO_(3))_(2),FeSbO_(4),Fe(SbO_(3))4,MoWO_(6),TiSnO_(4),coSbO_(4),and Ti(WO_(4))_(2)as promising catalysts,several of which have already been experimentally discovered for their robust OER performance,while others are novel for experimental exploration,thereby broadening the chemical sc.p. for efficient OER *** of the bond length of TM-O and the first ionization energy were used to unveil the OER activity *** the calculated results,guidance has been derived to effectively execute advanced high-throughput screenings for the discovery of catalysts with favorable ***,the intrinsic correlation between catalytic.p.rformance and various atomic and structural factors was elucidated using the ML *** these approaches,we not only streamline the choice of the promising electrocatalysts but also offer insights for the design of varied catalyst models and the discovery of superior c

关键词： Transition metal oxides Oxygen evolution reaction High-throughput screening First-princ.p.es calculation Machine learning

Synaptic a-Si:H/a-Ga_(2)O_(3) phototransistor inspired by the phototaxis behavior of organisms with all-optical and all-electrical stimulation modes

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Nano Research 2024年第8期17卷 7631-7642页

作者： Youngbin Yoon Youngki Kim Soowon choi Jungdae Kwon Myunghun Shin School of Electronics and Information Engineering Korea Aerospace UniversityGoyang10540Republic of Korea Nano Materials Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea Department of Materials Science and Engineering Pusan National UniversityBusan 46241Republic of Korea

To improve neuromorphic computing performance,neuromorphic system components should mimic the behaviors of organic *** this study,a synaptic a-Si:H/a-Ga_(2)O_(3)phototransistor featuring all-optical and-electrical emulation is fabricated in a manner advantageous for complementary metal-oxide-semiconductor process *** phototransistor exhibits excitatory and inhibitory synaptic behaviors under stimulation by both optical and electrical *** mimics several essential synaptic functions,including excitatory postsynaptic current,inhibitory postsynaptic current,short-term memory,long-term memory,pairedpulse facilitation,and spike-timing-dependent *** optical and electrical modulation mechanisms are confirmed to arise from the a-Si:H/a-Ga_(2)O_(3) heterojunction structure and interface effects,and the device is shown to operate at low power in both optical and electrical *** all-optical weight modulation function is applied to the wavelength-differential behavior response of zebrafish,successfully mimicking the color perc.p.ion process of the ***,to verify the translation of the optoelectrical-derived synaptic behaviors of the phototransistor into artificial neuromorphic computation,handwritten digit image recognition of the Modified National Institute of Standards and Technology dataset is performed by a convolutional neural network,with a demonstrated average learning accuracy of 98.46%.These findings verify the applicability of the synaptic a-Si:H/a-Ga_(2)O_(3) phototransistor in neuromorphic computing.

关键词： synaptic.p.ototransistor artificial synapse phototaxis neuromorphic computing interface charge state optoelectronic synaptic device