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Enhanced performance of solution-processed carbon nanotube transparent electrodes in foldable perovskite solar cells through vertical separation of binders by using eco-friendly parylene substrate

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Carbon Energy 2024年第7期6卷 83-93页

作者： Unsoo Kim Jeong-Seok Nam Jungjin Yoon Jiye Han Mansoo choi Il Jeon Department of Mechanical Engineering Seoul National UniversitySeoulRepublic of Korea Global Frontier Center for Multiscale Energy Systems Seoul National UniversitySeoulRepublic of Korea Frontier Energy Solution SeoulRepublic of Korea Department of Nano Engineering Department of Nano Science and TechnologySKKU Advanced Institute of Nanotechnology(SAINT)Sungkyunkwan University(SKKU)SuwonRepublic of Korea Department of Materials Science and Engineering Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA

The successful utilization of an eco-friendly and biocompatible parylene-C substrate for high-performance solution-processed double-walled carbon nanotube(CNT)electrode-based perovskite solar cells(PSCs)was *** the use of a novel inversion transfer technique,vertical separation of the binders from the CNTs was induced,rendering a stronger p-doping effect and thereby a higher conductivity of the *** resulting foldable devices exhibited a power conversion efficiency of 18.11%,which is the highest reported among CNT transparent electrode-based PSCs to date,and withstood more than 10,000 folding cycles at a radius of 0.5 mm,demonstrating unprecedented mechanical ***,solar modules were fabricated using entirely laser scribing processes to assess the potential of the solution-processable nanocarbon ***,this is the only one to be processed entirely by the laser scribing process and to be biocompatible as well as eco-friendly among the previously reported nonindium tin oxide-based perovskite solar modules.

关键词： double-walled carbon nanotubes parylene substrates perovskite modules perovskite solar cells solution-processable electrodes surfactant removal

Tetramic acid-motif natural products from a marine fungus Tolypocladium cylindrosporum FB06 and their anti-Parkinson activities

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Marine Life Science & Technology 2024年第1期6卷 84-92页

作者： Yuna Jung Chaesun Kwon Taeyeon Kim Jin Woo Lee Min-Kyoo Shin Sang hee Shim Natural Products Research Institute College of PharmacySeoul National UniversitySeoul 08826Republic of Korea College of Pharmacy and Research Institute of Pharmaceutical Sciences Seoul National UniversitySeoul 08826Republic of Korea College of Pharmacy Duksung Women’s UniversitySeoul 01369Republic of Korea

Tetramic acid-containing natural products are attracting significantly increasing attention from biologists and chemists due to their intriguing structures and biological *** the present study,two new tetramic acid alkaloids tolypyridone I(1)and tolypyridone J(2),together with five known ones(3–7),were isolated from cultures of a marine fungus Tolypocladium cylindrosporum FB06 isolate obtained from a marine sediment in Beaufort sea of North *** structures were elucidated using 1D,2D NMR,and *** configurations were established on the basis of 1H coupling constants,ROESY correlations and DP4 *** 2 was isolated as mixtures of rotational isomers with C-3 to C-7 axis between 4-hydroxy-2-pyridone and 1-ethyl-3,5-dimethylcyclohexane,hindering *** our unbiased screening to discover neuroprotective compounds in an in vitro Parkinson’s disease(PD)model,SH-SY5Y dopaminergic cells were treated with isolated compounds followed by treatment with 1-methyl-4-phenylpyridinium(MPP^(+)),a parkinsonian *** tested compounds,F-14329(7)significantly protected cells from MPP^(+)-induced ***^(+)-mediated cell death is known to be related to the regulation of Bcl-2 family proteins,specifically the down-regulation of anti-apoptotic Bcl-2 and the up-regulation of pro-apoptotic Bax *** with 2 mmol/L of MPP^(+)for 24 h significantly reduced Bcl-2 levels compared to control treated with ***,treatment with F-14329(7)attenuated such *** study demonstrates that tetramic acid-motif compounds could be potential lead compounds for treating PD.

关键词： Tolypocladium cylindrosporum Tetramic acid Tolypyridone Parkinson’s disease

The Cause of Institutionalized Private Tutoring in Korea:Defective Public Schooling or a Universal Desire for Family Reproduction?

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ECNU Review of Education 2024年第1期7卷 12-41页

作者： Sang Hoon Bae Kee Ho choi Sungkyunkwan University Seoul National University

Purpose:In Korea,private tutoring is considered a social evil that damages the capacity of public schooling and undermines social *** the government has implemented various policies to reduce private tutoring,ranging from improving the quality of education to providing"quasi-private tutoring"programs and regulating the shadow education market,total spending on private tutoring has continued to *** study examines a little noticed but important cause of institutionalized private tutoring in ***/Approach/Methods:The study employed a socio-ecological perspective to analyze both education and socio-structural *** extensive review of the government's private tutoring reduction policies and related literature was ***:Private tutoring functions as a means by which parents can help their children compete for admission to prestigious universities and pass on wealth and social status to their *** in private tutoring has become a social norm that is taken for *** root causes of institutionalized private tutoring lie in both educational and socio-structural ***/Nalue:The study suggests that government policies,when ignoring the long-established"grammar"of parents about children's education,may either end in failure or produce unintended consequences.

关键词： Private tutoring social reproduction unintended consequences upward mobility

TEAM:Transformer Encoder Attention Module for Video Classification

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Computer Systems Science & Engineering 2024年第2期48卷 451-477页

作者： Hae Sung Park Yong Suk choi Department of Artificial Intelligence Hanyang UniversitySeoulKorea Department of Computer Science Hanyang UniversitySeoulKorea

Much like humans focus solely on object movement to understand actions,directing a deep learning model’s attention to the core contexts within videos is crucial for improving video *** the recent study,Video Masked Auto-Encoder(VideoMAE)employs a pre-training approach with a high ratio of tube masking and reconstruction,effectively mitigating spatial bias due to temporal redundancy in full video *** steers the model’s focus toward detailed temporal ***,as the VideoMAE still relies on full video frames during the action recognition stage,it may exhibit a progressive shift in attention towards spatial contexts,deteriorating its ability to capture the main spatio-temporal *** address this issue,we propose an attention-directing module named Transformer Encoder Attention Module(TEAM).This proposed module effectively directs the model’s attention to the core characteristics within each video,inherently mitigating spatial *** TEAM first figures out the core features among the overall extracted features from each *** that,it discerns the specific parts of the video where those features are located,encouraging the model to focus more on these informative ***,during the action recognition stage,the proposed TEAM effectively shifts the VideoMAE’s attention from spatial contexts towards the core spatio-temporal *** attention-shift manner alleviates the spatial bias in the model and simultaneously enhances its ability to capture precise video *** conduct extensive experiments to explore the optimal configuration that enables the TEAM to fulfill its intended design purpose and facilitates its seamless integration with the VideoMAE *** integrated model,i.e.,VideoMAE+TEAM,outperforms the existing VideoMAE by a significant margin on Something-Something-V2(71.3%vs.70.3%).Moreover,the qualitative comparisons demonstrate that the TEAM encourages the model to disregard insignificant featur

关键词： Video classification action recognition vision transformer masked auto-encoder

Pulsed laser interference patterning of transition-metal carbides for stable alkaline water electrolysis kinetics

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Carbon Energy 2024年第5期6卷 65-80页

作者： Yewon Oh Jayaraman Theerthagiri Ahreum Min Cheol Joo Moon Yiseul Yu Myong Yong choi Department of Chemistry(BK21 FOUR) Research Institute of Natural SciencesGyeongsang National UniversityJinjuRepublic of Korea Core−Facility Center for Photochemistry and Nanomaterials Gyeongsang National UniversityJinjuRepublic of Korea

We investigated the role of metal atomization and solvent decomposition into reductive species and carbon clusters in the phase formation of transition-metal carbides(TMCs;namely,Co_(3)C,Fe_(3)C,TiC,and MoC)by pulsed laser ablation of Co,Fe,Ti,and Mo metals in *** interaction between carbon s-p-orbitals and metal d-orbitals causes a redistribution of valence structure through charge transfer,leading to the formation of surface defects as observed by X-ray photoelectron *** defects influence the evolved TMCs,making them effective for hydrogen and oxygen evolution reactions(HER and OER)in an alkaline ***_(3)C with more oxygen affinity promoted CoO(OH)intermediates,and the electrochemical surface oxidation to Co_(3)O_(4)was captured via in situ/operando electrochemical Raman probes,increasing the number of active sites for OER *** with more d-vacancies exhibits strong hydrogen binding,promoting HER kinetics,whereas Fe_(3)C and TiC with more defect states to trap charge carriers may hinder both OER and HER *** results show that the assembled membrane-less electrolyzer with Co_(3)C∥Co_(3)C and MoC∥MoC electrodes requires~2.01 and 1.99 V,respectively,to deliver a 10 mA cm−2 with excellent electrochemical and structural *** addition,the ascertained pulsed laser synthesis mechanism and unit-cell packing relations will open up sustainable pathways for obtaining highly stable electrocatalysts for electrolyzers.

关键词： acetone H_(2)and O_(2)evolution reactions pulsed laser ablation surface defects transition-metal carbides water electrolyzer

Sliding wear behavior of magnetorheological fluid for brass with and without magnetic field

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Transactions of Nonferrous Metals Society of China 2013年第2期23卷 400-405页

作者： Wan-Li SONG Chul-hee LEE seung-Bok choi Department of Mechanical Engineering Inha University

A pin-on-disc wear apparatus was used to carry out the tribological experiment of brass to investigate the effect of a magnetorheological （MR） fluid on the interfacial surface with and without magnetic field. A series of tests were performed at the loads of 20-100 N and rotating speeds of 127-425 r/min for 2 h. The friction coefficient and wear rate were monitored by the wear apparatus, while the microstructures of the worn surfaces were observed by scanning electron microscope （SEM）. In addition, the chemical composition of worn surfaces was analyzed by energy dispersive X-ray spectroscopy （EDS）. Test results show different friction and wear performance of the MR fluid with and without magnetic field. At the same time, the effects of various normal loads and rotating speeds on the tribological behavior were investigated. Through the investigation of the morphologies of the wom surfaces under the magnetic field, it is found that the MR particles are clearly evident on the wom surface and the plastic flow of ridges causes the lateral extrusion. This directly indicates that abrasive wear is the predominant wear mechanism observed with MR fluid.

关键词： magnetorheological fluid sliding wear brass magnetic field friction coefficient

Alleviatory effect of isoquercetin on benign prostatic hyperplasia via IGF-1/PI3K/Akt/mTOR pathway

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Food Science and Human Wellness 2024年第3期13卷 1698-1710页

作者： Young-Jin choi Meiqi Fan Nishala Erandi Wedamulla Yujiao Tang Eun-Kyung Kim Department of Food Science and Nutrition Dong-A UniversityBusan 49315Republic of Korea Center for Silver-targeted Biomaterials Brain Busan 21 Plus programDong-A UniversityBusan 49315Republic of Korea Department of Health Sciences the Graduate School of Dong-A UniversityBusan 49315Republic of Korea Division of Food Bioscience College of Biomedical and Health SciencesKonkuk UniversityChungju 27478Republic of Korea Department of Export Agriculture Faculty of Animal Science and Export AgricultureUva Wellassa UniversityBadulla 90000Sri Lanka School of Bio-Science and Food Engineering Changchun University of Science and TechnologyChangchun 130600China Nutritional Education Major Graduate School of EducationDong-A UniversityBusan 49315Republic of Korea Nutrinomics Lab.Co. Ltd.Busan 49315Republic of Korea

We evaluated the effect of isoquercetin(quercetin-O-3-glucoside-quercetin,IQ)as a functional component of Abeliophyllum disistichum Nakai ethanol extract(ADLE)on prostate cell proliferation and apoptosis and its effects on the IGF-1/PI3K/Akt/mTOR pathway in benign prostatic hyperplasia(BPH).Metabolites in ADLE were analyzed using UHPLC-qTOF-MS and *** was orally administered(1 or 10 mg/kg)to a testosterone propionate-induced BPH rat model,and its effects on the prostate weight were *** effect of IQ on androgen receptor(AR)signaling was analyzed in LNCaP *** IGF-1 and IQ affect the IGF-1/PI3K/Akt/mTOR pathway in BPH-1 cells was also *** metabolites in ADLE were identified and quantified,which confirmed that ADLE contained abundant IQ(20.88 mg/g).IQ significantly reduced the prostate size in a concentration-dependent manner in a BPH rat model,and significantly decreased the expression of AR signaling factors in the rat prostate tissue and LNCaP cells in a concentration-dependent *** also inhibited the PI3K/AKT/mTOR pathway activated by IGF-1 treatment in BPH-1 *** BPH-1 cells,IQ led to G0/G1 arrest and suppressed the expression of proliferation factors while inducing ***,IQ shows potential for use as a pharmaceutical and nutraceutical for BPH.

关键词： Isoquercetin Benign prostatic hyperplasia Androgen receptor signaling PI3K/Akt/mtor pathway

Influence of the wastewater composition on denitrification and biological P-removal in the S-DN-P process: (c) Dissolved and undissolved substrates

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Journal of Environmental Sciences 2009年第8期21卷 1074-1079页

作者： hee-Jeong choi Chul-Ho choi seung-Mok Lee Diwakar Tiwari Department of Environmental Engineering Kwandong University Department of Chemistry School of Physical Sciences Mizoram University

The denitdfication and P-removal in the sorption-denitrification-P-removal （S-DN-P） process were carded out under various wastewater compositions. It is noted that P-removal largely depends on the wastewater composition as well to the quantity of the substrates present in wastewater fraction. Three different wastewater fractions are obtained as： raw wastewater, dissolved wastewater （obtained with filtration using 0.45 μm filter）, and undissolved wastewater （i.e., infiltrate obtained by above filtration）. The ratio of P-release/CODtotal-consumption clearly inferred that undissolved wastewater possess very low value i.e., 0.0008 followed by raw wastewater 0.008 and dissolved wastewater 0.03. When this ratio was nearby 0.01, enhanced P-removal was observed. Moreover, the ratio of P-uptake to NO3^--N decomposition for raw wastewater was two times for dissolved wastewater. Interestingly, it was observed that the P-removal and denitrification depend not only on the dissolved substrates but also the undissolved substrates present in the wastewater. The result of the P-removal obtained with this S-DN-P process did not show a big difference of 36%, 34% and 30%, respectively, for raw, dissolved and undissolved wastewater.

关键词： denitrification polyhydroxybutyrate sequencing batch biofilm reactor sorption denitrification P-removals

Effect of pre-twinning and heat treatment on formability of AZX311 Mg alloy

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Journal of Magnesium and Alloys 2024年第3期12卷 1154-1169页

作者： Mahesh Panchal Lalit Kaushik Min-Seong Kim Ravi Kottan Renganayagalu Shi-Hoon choi Jaiveer Singh Department of Mechanical Engineering Indian Institute of Technology JodhpurKarwarJodhpur 342030RajasthanIndia Department of Metallurgical and Materials Engineering Indian Institute of Technology JodhpurKarwarJodhpur 342030RajasthanIndia Energy Materials Research Center Korea Institute of Science and Technology(KIST)5 Hwarang-roSeongbuk-guSeoul 02792Republic of Korea Department of Advanced Components and Materials Engineering Sunchon National University255 Jungang-roSuncheonJeonnam 57922Republic of Korea

In this study,the effects of pre-strain-induced tensile twins(TTWs)and controlled heat treatment on the formability behavior of AZX311 Mg alloy sheets were investigated.A 4%compressive strain was applied to pre-strain the sheets using the in-plane compression(IPC)technique along the rolling direction(RD)to introduce *** pre-strained(PS)samples were subsequently heat-treated at 250℃,350℃,and 400℃ independently for 1 hr,and are termed as PSA1,PSA2,and PSA3,*** cupping tests were conducted to assess the formability of the sheet samples under different initial *** results showed that the PS sample heat-treated at 250℃ for 1hr exhibited a decrease in the Erichsen index(IE)compared to the as-rolled sample,whereas PSA2 and PSA3 samples showed an increase in IE *** analysis revealed that most of the TTWs generated through pre-twinning were stable at 250℃;however,the twin volume fraction reduced to 41%at 350℃ compared to the PS samples due to enhanced thermal activity at that ***,PSA2 samples showed severe grain coarsening in some areas of the sample,and the fraction of such grains increased in the PSA3 *** stretch formability(IE value)of PSA2 samples showed a 32.3%increase compared to the as-rolled ***,the analysis of the deformed specimen at failure under the Erichsen test indicated that considerable detwinning occurs in the PS and PSA1 samples,whereas dislocation slip activity dominates in the PSA2 and PSA3 samples during stretch *** from detwinning and dislocation slip,deformation twins were also observed in all samples after the Erichsen ***,this work highlights the importance of texture control and its underlying mechanisms via pre-twinning followed by heat treatment and their impact on the room temperature(RT)stretch formability of AZX311 Mg alloy sheets.

关键词： Mg alloys Pre-twinning Texture Formability EBSD.