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Transactions of Nonferrous Metals Society of China 2024年

作者： Yeongjung Kim Yong-sung Eom Kwang-Seong choi Jong-Hyun Lee Department of Materials Science and Engineering Seoul National University of Science and Technology 232 Gongneung-ro Low-Carbon Integration Tech Creative Research Section ETRI 218 Gajeong-ro Materials Research Institute for Future Convergence Seoul National University of Science and Technology 232 Gongneung-ro

Four types of submicron Ag-coated Cu particles with different Ag contents were prepared as sintering paste fillers， and the Ag contents of the particles were measured to be 10， 20， 30， and 40 wt%. Four types of particles （in order of increasing Ag content: A10， A20， A30， and A40） were surface-modified with stearic acid， to suppress the Ag shell dewetting and improve sinterability. The surface-modified particles were mixed with a polyol-based solvent to fabricate a resin-free paste. Subsequently， the pastes were screen-printed onto a slide glass and sintered at 250 ℃ in a nitrogen atmosphere for 1–10 min to form an electrode. The electrical resistivity of the sintered film as a function of sintering time was measured using a four-point probe. All the four surface-modified Cu@Ag particles with different Ag contents exhibited decreased electrical resistivity. Particularly， the largest difference in values after and before the surface modification was observed for A40 with the highest Ag content; the electrical resistivities of the initial and surface-modified particles were 1.51×10-4and 6.67×10-5Ω·cm， respectively， after sintering for 10 min. The findings of this study confirmed that the surface modification using stearic acid effectively suppressed the dewetting of the Ag shell and improved the sinterability of the submicron Cu@Ag particles.

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h─STABILITY FOR NONLINEAR PERTURBED SYSTEMS

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Annals of Differential Equations 1995年第1期11卷 1-9页

作者： sung kyu choi and Nam Jip Koo (Chungnam National University, Korea)

In this paper, we obtain 'Roughness' theorems for h-stability of the nonlinear perturbed systems using the comparison method and some integral inequalities.

关键词： Nonliear perturbed systems h-stability h-stability in variation

Surface-functionalized hole-selective monolayer for high efficiency single-junction wide-bandgap and monolithic tandem perovskite solar cells

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Journal of Energy Chemistry 2024年第1期88卷 317-326,I0008页

作者： Devthade Vidyasagar Yeonghun Yun Jae Yu Cho Hyemin Lee kyung Won Kim Yong Tae Kim sung Woong Yang Jina Jung Won Chang choi Seonu Kim Rajendra Kumar Gunasekaran Seok Beom Kang Kwang Heo Dong Hoe Kim Jaeyeong Heo Sangwook Lee School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Department of Materials Science and Engineering and Optoelectronics Convergence Research CenterChonnam National UniversityGwangju 61186Republic of Korea Department of Materials Science and Engineering Korea UniversitySeoul 02841Republic of Korea Department of Nanotechnology and Advanced Materials Engineering Sejong UniversitySeoul 05006Republic of Korea

Carbazole moiety-based 2PACz([2-(9H-carbazol-9-yl)ethyl]phosphonic acid)self-assembled monolayers(SAMs)are excellent hole-selective contact(HSC)materials with abilities to excel the charge-transferdynamics of perovskite solar cells(PSCs).Herein,we report a facile but powerful method to functionalize the surface of 2PACz-SAM,by which reproducible,highly stable,high-efficiency wide-bandgap PSCs can be obtained.The 2PACz surface treatment with various donor number solvents improves assembly of 2PACz-SAM and leave residual surface-bound solvent molecules on 2PACz-SAM,which increases perovskite grain size,retards halide segregation,and accelerates hole extraction.The surface functionalization achieves a high power conversion efficiency(PCE)of 17.62%for a single-junction wide-bandgap(~1.77 e V)PSC.We also demonstrate a monolithic all-perovskite tandem solar cell using surfaceengineered HSC,showing high PCE of 24.66%with large open-circuit voltage of 2.008 V and high fillfactor of 81.45%.Our results suggest this simple approach can further improve the tandem device,when coupled with a high-performance narrow-bandgap sub-cell.

关键词： Perovskite solar cells 2PACz Monolithic tandem solar cells Wide bandgap

ASYMPTOTIC EQUIVXLENCE BETWEEN TWO LINEAR DIFFERENTIAL SYSTEMS

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Annals of Differential Equations 1997年第1期13卷 44-52页

作者： sung kyu choi(Chuttgnam National University, Korea)Yoon Hoe Goo(Hanseo University, Korea)Nam Jip Koo(Chungnam National University, Korea)

In this paper, we study the asymptotic equivalence between two systems

关键词： Asymptotic Equivalence Class H

Catalpa bignonioides extract improves exercise performance through regulation of growth and metabolism in skeletal muscles

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Asian Pacific Journal of Tropical Biomedicine 2024年第2期14卷 47-54页

作者： Hoibin Jeong Dong-joo Lee sung-Pil Kwon SeonJu Park Song-Rae Kim Seung Hyun Kim Jae-Il Park Deug-chan Lee kyung-Min choi WonWoo Lee Ji-Won Park Bohyun Yun Su-Hyeon Cho Kil-Nam Kim Seoul Center Korea Basic Science InstituteSeoul 02841Republic of Korea Chuncheon Center Korea Basic Science InstituteChuncheon 24341Republic of Korea Research&Development Center Chungdam CDC JNPharm LLC.Chuncheon 24341Republic of Korea Department of Biomedical Technology Kangwon National UniversityChuncheon 24341Republic of Korea Yonsei Institute of Pharmaceutical Sciences College of PharmacyYonsei UniversityIncheon 21983Republic of Korea Gwangju Center Korea Basic Science InstituteGwangju 61751Republic of Korea Honam National Institute of Biological Resources 99Gohadoan-gilMokpo-siJeollanam-do58762Republic of Korea Department of Bio-analysis Science University of Science&TechnologyDaejeon34113Republic of Korea

Objective:To evaluate the effects of Catalpa bignonioides fruit extract on the promotion of muscle growth and muscular capacity in vitro and in vivo.Methods:Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Cell proliferation was assessed using a 5-bromo-2’-deoxyuridine(BrdU)assay kit.Western blot analysis was performed to determine the protein expressions of related factors.The effects of Catalpa bignonioides extract were investigated in mice using the treadmill exhaustion test and whole-limb grip strength assay.Chemical composition analysis was performed using high-performance liquid chromatography(HPLC).Results:Catalpa bignonioides extract increased the proliferation of C2C12 mouse myoblasts by activating the Akt/mTOR signaling pathway.It also induced metabolic changes,increasing the number of mitochondria and glucose metabolism by phosphorylating adenosine monophosphate-activated protein kinase.In an in vivo study,the extract-treated mice showed improved motor abilities,such as muscular endurance and grip strength.Additionally,HPLC analysis showed that vanillic acid may be the main component of the Catalpa bignonioides extract that enhanced muscle strength.Conclusions:Catalpa bignonioides improves exercise performance through regulation of growth and metabolism in skeletal muscles,suggesting its potential as an effective natural agent for improving muscular strength.

关键词： Catalpa bignonioides Skeletal muscle Cell proliferation Mitochondria Energy metabolism C2C12

Nanocrystalline Iron Pyrophosphate-Regulated Amorphous Phosphate Overlayer for Enhancing Solar Water Oxidation

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Nano-Micro Letters 2022年第12期14卷 387-400页

作者： Chengkai Xia Yuankai Li Minyeong Je Jaekyum Kim sung Min Cho Chang Hyuck choi Heechae choi Tae-Hoon Kim Jung kyu Kim School of Chemical Engineering Sungkyunkwan University(SKKU)2066 Seobu-roJangan-guSuwon 16419Republic of Korea Theoretical Materials and Chemistry Group Institute of Inorganic ChemistryUniversity of CologneGreinstr.650939 CologneGermany Department of Chemistry Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Department of Materials Science and Engineering Engineering Research CenterChonnam National UniversityGwangju 61186Republic of Korea

A rational regulation of the solar water splitting reaction pathway by adjusting the surface composition and phase structure of catalysts is a substantial approach to ameliorate the sluggish reaction kinetics and improve the energy conversion efficiency.In this study,we demonstrate a nanocrystalline iron pyrophosphate(Fe_(4)(P_(2)O_(7))_(3),FePy)-regulated hybrid overlayer with amorphous iron phosphate(FePO_(4),FePi)on the surface of metal oxide nanostructure with boosted photoelectrochemical(PEC)water oxidation.By manipulating the facile electrochemical surface treatment followed by the phosphating process,nanocrystalline FePy is localized in the FePi amorphous overlayer to form a heterogeneous hybrid structure.The FePy-regulated hybrid overlayer(FePy@FePi)results in significantly enhanced PEC performance with long-term durability.Compared with the homogeneous FePi amorphous overlayer,FePy@FePi can improve the charge transfer efficiency more significantly,from 60% of FePi to 79%of FePy@FePi.Our density-functional theory calculations reveal that the coexistence of FePi and FePy phases on the surface of metal oxide results in much better oxygen evolution reaction kinetics,where the FePi was found to have a typical down-hill reaction for the conversion from OH*to O_(2),while FePy has a low free energy for the formation of OH*.

关键词： Water oxidation Photoelectrochemical cell Metal pyrophosphate Electrochemical surface treatment

健康中国与体育强国背景下的中小学健美操推广策略研究

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赤峰学院学报（自然科学版） 2024年第1期40卷 86-89页

作者：夏晓雨 choi Mee-sung 蔡金张艳 Dongshin University Naju-si Jeollanam-doRepublic of Korea 58245 沈阳师范大学辽宁沈阳110034

在健康中国与体育强国的双重背景下,学校体育成为中小学生身心健康全面发展中的重要一环。健美操能够提升学生身心素质,有助于提高中小学生文化课学习效率。当前健美操运动未能在中小学得到广泛推广,主要表现在推广力度不够、师资力量... 详细信息

在健康中国与体育强国的双重背景下,学校体育成为中小学生身心健康全面发展中的重要一环。健美操能够提升学生身心素质,有助于提高中小学生文化课学习效率。当前健美操运动未能在中小学得到广泛推广,主要表现在推广力度不够、师资力量不足、设施和器材不完善,以及缺乏有效的评估和激励机制等。其根本原因在于对中小学推广健美操的重要价值与意义缺乏深层次的认识和理解。因此,本文通过分析我国中小学健美操的发展现状及存在问题,以期能够促进健美操运动的推广和普及,更好地提高学生的身体素质、促进学生的心理健康、培养学生的团队合作精神。

关键词：健康中国体育强国健美操中小学

A conformal titanyl phosphate amorphous overlayer for enhancing photoelectrochemical hydrogen peroxide production

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Journal of Energy Chemistry 2023年第11期86卷 399-408,I0009页

作者： Jaekyum Kim Young Eun Kim Minyeong Je Won Tae Hong Chang-Lyoul Lee Tae-Hoon Kim sung Min Cho Chang Hyuck choi Heechae choi Woo-Seok Choe Jung kyu Kim School of Chemical Engineering Sungkyunkwan University(SKKU)Suwon 16419Republic of Korea SKKU Advanced Institute of Nano Technology(SAINT) Sungkyunkwan University(SKKU)Suwon 16419Republic of Korea Theoretical Materials&Chemistry Group Institute of Inorganic ChemistryUniversity of CologneGreinstr.650939CologneGermany Advanced Photonics Research Institute(APRI) Gwangju Institute of Science and Technology(GIST)Gwangju 61005Republic of Korea Department of Materials Science and Engineering Chonnam National UniversityGwangju 61186Republic of Korea Department of Chemistry Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Institute for Convergence Research and Education in Advanced Technology(I-CREATE) Yonsei UniversitySeoul 03722Republic of Korea Department of Chemistry Xi’an Jiaotong-Liverpool UniversitySuzhou 215123JiangsuChina

Photoelectrochemical(PEC)H_(2)O_(2)production through water oxidation reaction(WOR)is a promising strategy,however,designing highly efficient and selective photoanode materials remains challenging due to competitive reaction pathways.Here,for highly enhanced PEC H_(2)O_(2)production,we present a conformal amorphous titanyl phosphate(a-TP)overlayer on nanoparticulate TiO_(2)surfaces,achieved via lysozyme-molded in-situ surface reforming.The a-TP overlayer modulates surface adsorption energies for reaction intermediates,favoring WOR for H_(2)O_(2)production over the competing O_(2)evolution reaction.Our density functional theory calculations reveal that a-TP/TiO_(2)exhibits a substantial energy uphill for the O·*formation pathway,which disfavors O_(2)evolution but promotes H_(2)O_(2)production.Additionally,the a-TP overlayer strengthens the built-in electric field,resulting in favorable kinetics.Consequently,a-TP/TiO_(2)exhibits 3.7-fold higher Faraday efficiency(FE)of 63%at 1.76 V vs.reversible hydrogen electrode(RHE)under 1 sun illumination,compared to bare TiO_(2)(17%),representing the highest FE among TiO_(2)-based WOR H_(2)O_(2)production systems.Employing the a-TP overlayer constitutes a promising strategy for controlling reaction pathways and achieving efficient solar-to-chemical energy conversion.

关键词： Solar H_(2)O_(2) production In-situ surface reforming Titanyl phosphate Amorphous overlayer Reaction pathway control

High-Performance Perovskite Quantum Dot Solar Cells Enabled by Incorporation with Dimensionally Engineered Organic Semiconductor

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Nano-Micro Letters 2022年第12期14卷 272-285页

作者： Seyeong Lim Dae Hwan Lee Hyuntae choi Yelim choi Dong Geon Lee sung Beom Cho Seonkyung Ko Jongmin choi Younghoon Kim Taiho Park Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Department of Materials Science and Engineering Hanyang UniversitySeoul 04763Republic of Korea Center of Materials Digitalization Korea Institute of Ceramic Engineering and Technology(KICET)Jinju 52851Republic of Korea Department of Materials Science and Engineering Ajou UniversitySuwon 16499Republic of Korea Department of Energy Science and Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)Daegu 42988Republic of Korea Department of Chemistry Kookmin UniversitySeoul 02707Republic of Korea

Perovskite quantum dots(PQDs)have been considered promising and effective photovoltaic absorber due to their superior optoelectronic properties and inherent material merits combining perovskites and QDs.However,they exhibit low moisture stability at room humidity(20-30%)owing to many surface defect sites generated by inefficient ligand exchange process.These surface traps must be re-passivated to improve both charge transport ability and moisture stability.To address this issue,PQD-organic semiconductor hybrid solar cells with suitable electrical properties and functional groups might dramatically improve the charge extraction and defect passivation.Conventional organic semiconductors are typically low-dimensional(1D and 2D)and prone to excessive self-aggregation,which limits chemical interaction with PQDs.In this work,we designed a new 3D star-shaped semiconducting material(Star-TrCN)to enhance the compatibility with PQDs.The robust bonding with Star-TrCN and PQDs is demonstrated by theoretical modeling and experimental validation.The Star-TrCN-PQD hybrid films show improved cubic-phase stability of CsPbI_(3)-PQDs via reduced surface trap states and suppressed moisture penetration.As a result,the resultant devices not only achieve remarkable device stability over 1000 h at 20-30%relative humidity,but also boost power conversion efficiency up to 16.0%via forming a cascade energy band structure.

关键词： CsPbI3 quantum dots Star-shaped organic semiconductors Hybrid perovskite quantum dots Solar cell stability High-efficiency photovoltaics

Effect of PAIP1 on the metastatic potential and prognostic significance in oral squamous cell carcinoma

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International Journal of Oral Science 2022年第1期14卷 113-122页

作者： Neeti Swarup Kyoung-Ok Hong Kunal Chawla Su-Jung choi Ji-Ae Shin kyu-Young Oh Hye-Jung Yoon Jae-Il Lee sung-Dae Cho Seong-Doo Hong Department of Oral Pathology School of Dentistry and Dental Research InstituteSeoul National UniversitySeoulRepublic of Korea Department of Computer Science School of Interactive ComputingGeorgia Institute of TechnologyAtlantaGAUSA

Poly Adenylate Binding Protein Interacting protein 1(PAIP1) plays a critical role in translation initiation and is associated with the several cancer types. However, its function and clinical significance have not yet been described in oral squamous cell carcinoma(OSCC) and its associated features like lymph node metastasis(LNM). Here, we used the data available from Gene Expression Omnibus(GEO), The Cancer Genome Atlas(TCGA), and Clinical Proteomic Tumor Analysis Consortium(CPTAC) to analyze PAIP1 expression in oral cancer. The publicly available data suggests that PAIP1 mRNA and protein levels were increased in OSCC. The high PAIP1 expression was more evident in samples with advanced stage, LNM, and worse pattern of invasion. Moreover, the in vitro experiments revealed that PAIP1 knockdown attenuated colony forming, the aggressiveness of OSCC cell lines, decreasing MMP9 activity and SRC phosphorylation. Importantly, we found a correlation between PAIP1 and pSRC through the analysis of the IHC scores and CPTAC data in patient samples. Our findings suggest that PAIP1 could be an independent prognostic factor in OSCC with LNM and a suitable therapeutic target to improve OSCC patient outcomes.

关键词： squamous invasion metastasis