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Friction 2024年第9期12卷 2089-2107页

作者： Hao-Ran CHENG Ki-Hoon SHIN hong Seok kim Department of Mechanical Engineering Graduate School of Seoul National University of Science and TechnologySeoul 01811Republic of Korea Department of Mechanical and Automotive Engineering Seoul National University of Science and TechnologySeoul 01811Republic of Korea

This study focused on producing metal matrix composite(MMC)coatings on Ti–6Al–4V alloy through laser surface alloying using a novel combination of Inconel 625 and SiC precursor *** ratios of alloying powders were examined to evaluate surface properties such as microhardness,wear resistance,and friction coefficient,along with analyzing the phase composition and microstructure of the *** in situ synthesized MMC coatings exhibited the presence ofα-Ti,NiTi,NiTi_(2),and TiC ***,Ti_(5)Si_(3)andα-Ti/Ti_(5)Si_(3)eutectic structures were observed when the SiC content exceeded 20%.In comparison to the titanium substrate,the MMC coating significantly enhanced microhardness by over threefold and reduced wear by 95%.However,it was crucial to carefully select the appropriate combination of alloying powders to avoid a substantial decrease in friction performance and excessive formation of *** a comparative analysis of experimental results,the optimal precursor material composition was identified as 85%Inconel 625 and 15%*** study demonstrated the effective utilization of Inconel 625 and SiC alloying materials to enhance the surface properties of titanium alloys,thereby expanding their application in challenging environments.

关键词： titanium alloy Inconel 625 SiC ceramic laser surface alloying metal matrix composite(MMC)

Surface-modified Ag@Ru-P25 for photocatalytic CO_(2) conversion with high selectivity over CH_(4) formation at the solid–gas interface

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Carbon Energy 2024年第1期6卷 182-196页

作者： Chaitanya B.Hiragond Sohag Biswas Niket SPowar Junho Lee Eunhee Gong Hwapyong kim hong Soo kim Jin-Woo Jung Chang-Hee Cho Bryan M.Wong Su-Il In Department of Energy Science&Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)DaeguRepublic of Korea Department of Chemical&Environmental Engineering Materials Science&Engineering ProgramDepartment of ChemistryDepartment of Physics&AstronomyUniversity of California-RiversideRiversideCaliforniaUSA Department of Physics and Chemistry Daegu Gyeongbuk Institute of Science and Technology(DGIST)DaeguRepublic of Korea NiceScience Corporation DaeguRepublic of Korea

Systematic optimization of the photocatalyst and investigation of the role of each component is important to maximizing catalytic activity and comprehending the photocatalytic conversion of CO_(2) reduction to solar fuels.A surface-modified Ag@Ru-P25 photocatalyst with H_(2)O_(2) treatment was designed in this study to convert CO_(2) and H_(2)O vapor into highly selective *** doping followed by Ag nanoparticles(NPs)cocatalyst deposition on P25(TiO_(2))enhances visible light absorption and charge separation,whereas H_(2)O_(2) treatment modifies the surface of the photocatalyst with hydroxyl(–OH)groups and promotes CO_(2) ***-resonance transmission electron microscopy,X-ray photoelectron spectroscopy,X-ray absorption near-edge structure,and extended X-ray absorption fine structure techniques were used to analyze the surface and chemical composition of the photocatalyst,while thermogravimetric analysis,CO_(2) adsorption isotherm,and temperature programmed desorption study were performed to examine the significance of H_(2)O_(2) treatment in increasing CO_(2) reduction *** optimized Ag1.0@Ru1.0-P25 photocatalyst performed excellent CO_(2) reduction activity into CO,CH4,and C2H6 with a~95%selectivity of CH4,where the activity was~135 times higher than that of pristine TiO_(2)(P25).For the first time,this work explored the effect of H_(2)O_(2) treatment on the photocatalyst that dramatically increases CO_(2) reduction activity.

关键词： gas-phase CO_(2) reduction H_(2)O_(2) treatment plasmonic nanoparticles solar fuel photocatalyst surface modification

Regulation of sleep by astrocytes in the hypothalamic ventrolateral preoptic nucleus

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Neural Regeneration Research 2025年第4期20卷 1098-1100页

作者： Jae-hong kim Ruqayya Afridi Il-Sung Jang Maan Gee Lee Kyoungho Suk Brain Korea 21 four KNU Convergence Educational Program of Biomedical Sciences for Creative Future Talents School of MedicineKyungpook National UniversityDaeguRepublic of Korea Department of Pharmacology School of MedicineKyungpook National UniversityDaeguRepublic of Korea Department of Pharmacology School of DentistryKyungpook National UniversityDaeguRepublic of Korea Brain Science&Engineering Institute Kyungpook National UniversityDaeguRepublic of Korea

Astrocytes are functionally dynamic cells that support neurons in multiple ways throughout an organism’s *** astrocytic regulation of neuronal activity has been increasingly recognized in recent *** are now recognized as playing a more complex role than mere bystanders in the central nervous ***,their role in regulating the sleep neurocircuitry is not well *** this perspective,we highlight the role of astrocytes in sleep modulation,with a particular focus on regulatory mechanisms related to the ventrolateral preoptic nucleus(VLPO)of the *** briefly discuss recent literature reporting the role of VLPO astrocytes in regulating sleep-associated behaviors.

关键词： sleep ventrolateral astrocytes

Preoperative risk factors for early recurrence in patients with resectable pancreatic ductal adenocarcinoma after curative intent surgical resection

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Hepatobiliary & Pancreatic Diseases International 2018年第5期17卷 450-455页

作者： Nam Hee kim hong Joo kim Division of Gastroenterology Department of Internal Medicine Kangbuk Samsung Hospital Sungkyunkwan University School of Medicine

Background: Postoperative early recurrence(ER) in patients with pancreatic ductal adenocarcinoma(PDAC) is frequently encountered after curative intent surgery. Nonetheless, clinical significance and risk factors of ER after surgery for PDAC have not been extensively investigated. The aim of this study was to determine preoperative risk predictors for ER in patients with PDAC after upfront surgery. Methods: Eighty-one consecutive patients with PDAC who underwent curative intent surgical resection at Kangbuk Samsung Hospital between January 2004 and May 2015 were enrolled. ER was defined as tumor relapse within 6 months after surgery. Results: ER occurred in 26 patients(32.1%), whereas 49 patients(60.5%) had late recurrence( ≥ 6 months after surgery), and 6 patients had no recurrence(7.4%). Univariate analysis showed that C-reactive protein(CRP) > 3.0 mg/dL, modified Glasgow prognostic score(mGPS) = 2, decrease of total lymphocyte count by > 50% of baseline value in the preoperative period, prognostic nutritional index(PNI) 3.0 mg/dL, decrease of total lymphocyte count by > 50% of baseline value, and preoperative SUVmax were significant and independent contributors of ER in patients with resectable PDAC who underwent curative intent surgery. Conclusions: Postoperative ER for resectable PDAC was frequent with poor prognosis after curative intent upfront surgery. It is reasonable to suggest that there is a subgroup of resectable PDAC patients at highrisk of ER and neoadjuvant therapy should be considered in these patients in a clinical trial setting.

关键词： Early recurrence Pancreatic ductal adenocarcinoma Preoperative risk factors C-reactive protein Maximum standardized uptake value

关于动画帧结构装置的相关研究——以罗伯特·布里尔的作品为例

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当代动画 2024年第2期 116-123页

作者： [韩]金鸿钧石璨韩国韩瑞大学艺术学院中南财经政法大学中韩新媒体学院

动画的媒体特征与实拍电影不同,其中之一便是帧生成方式的差异。不同于实拍电影通过连续拍摄生成纪录图像,动画作品是以分帧拍摄方式手动生成图像。相较于动画作品,强调图像联想和非连续性的实验动画中的帧,是一种独立的空间,形成自我... 详细信息

动画的媒体特征与实拍电影不同,其中之一便是帧生成方式的差异。不同于实拍电影通过连续拍摄生成纪录图像,动画作品是以分帧拍摄方式手动生成图像。相较于动画作品,强调图像联想和非连续性的实验动画中的帧,是一种独立的空间,形成自我指向性联想体系,强调视觉吸引的自律特性。罗伯特·布里尔的作品《富士》是体现动画帧结构特性的作品,由写实影像、转描技术以及抽象形态和多种彩色技法构成,让观众感受不同电影的形式特点。在这部作品中,观众可以体验到包括帧的独立性及连续性、空间和时间、现实和再现、二维和三维、连续和断裂等在内的无数双重结构,其装置特性主要在于突出单帧独立空间的自律特性。

关键词：帧实验动画自律性联想

Factors associated with axial length elongation in high myopia in adults

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International Journal of Ophthalmology(English edition) 2021年第8期14卷 1231-1236页

作者： hong Kyu kim Sung Soo kim Department of Ophthalmology Dankook University HospitalDankook University College of MedicineCheonan 31116Republic of Korea Yonsei University Graduate School of Medicine Seoul 03722Republic of Korea Department of Ophthalmology Severance HospitalInstitute of Vision ResearchYonsei University College of MedicineSeoul 03722Republic of Korea

AIM:To investigate the association of axial length(AL)and ocular factors on AL ***:A retrospective chart review of patients who underwent two or more AL examinations for more than two *** 4 groups were divided according to initial AL(<24 mm,24-26 mm,26-28 mm,≥28 mm).Initial fundus photograph was used to find risk factors associated AL ***:The mean age of the patients was 47.21±7.79 *** remained almost unchanged in the groups with AL<24 mm and 24≤AL<26 *** the contrary,AL increased by 0.011 mm/y in the group with 26≤AL<28 mm and 0.035 mm/y in the group with AL≥28 mm(P<0.001).In high myopia,AL elongation increased in eye with longer AL(r=0.003,P=0.024),female gender(r=0.014,P=0.019),eye with larger peripapillary chorioretinal atrophic area(r=0.002,P=0.019),and smaller vascular arcade angle(r=-0.004,P=0.006).The risk of elongation 0.03 mm/y in high myopia was increased in female gender(P=0.040),and gradually increased in eye with large peripapillary chorioretinal atrophy area(P<0.01).CONCLUSION:AL elongate significantly in the eye with longer AL,female gender,and the eye with larger atrophic area and smaller arcade angle on fundus photography.

关键词： axial length elongation fundus photography high myopia myopic complication

Adsorption properties of polycarboxylate ether-based superplasticizer on cement particles and their resultant dispersion

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Frontiers of Structural and Civil Engineering 2022年第4期16卷 506-514页

作者： Jinyoung YOON Byoung Il CHOI Jae hong kim Department of Structural Engineering Research Korea Institute of Civil Engineering and Building Technology(KICT)Goyang 10223Republic of Korea System Safety Research Department Korea Shipbuilding and Offshore EngineeringSeongnam 13591Republic of Korea Department of Civil and Environmental Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea

The cement dispersion performance of a polycarboxylate(PCE)-based superplasticizer is highly related to their adsorption behaviors as a function of *** study evaluated effects of PCEs on rheological properties of cementitious ***,characteristics of PCEs were characterized via permeation chromatography(GPC)and Fourier-transform infrared spectrometry(FT-IR).The adsorption behavior of single and blended PCEs on cementitious composites was identified using total organic carbon analyzer(TOC).Based on the measurement of PCE adsorption,the changes of rheological properties of cementitious materials as well as the number of dispersed cement particles were characterized using a rheometer and laser spectroscopy,*** experimental results support the systematic mechanism of PCE adsorption,cement dispersion,and the decrease in viscosity of cementitious materials.

关键词： adsorption polycarboxylate superplasticizer rheology dispersion

Duo Property on the Monoid of Regular Elements

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Algebra Colloquium 2022年第2期29卷 203-216页

作者： Chan Yong hong hong Kee kim Nam Kyun kim Tai Keun Kwak Yang Lee Department of Mathematics Kyung Hee UniversitySeoul 02447Korea Department of Mathematics and RINS Gyeongsang National University Jinju 52828Korea School of Basic Sciences Hanbat National UniversityDaejeon 34158Korea Department of Mathematics Daejin UniversityPocheon 11159Korea Department of Mathematics Yanbian UniversityYanjiJilin 133002China Instituteof Basic Science Daejin UniversityPocheon 11159Korea

We study the right duo property on regular elements,and we say that rings with this property are right *** is first shown that the right duo property is preserved by right quotient rings when the given rings are right *** prove that thepolynomial ring over a ring R is right DR if and only if R is *** is also proved that for a prime number p,the group ring KG of a finite p-group G over a field K of characteristic p is right DR if and only if it is right duo,and that there exists a group ring KG that is neither DR nor duo when G is not a p-group.

关键词： right DR ring right duo ring quotient ring (skew)polynomial ring group ring

On the Classification of Positive Quaternionic Khler Manifolds with b_4=1

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Acta Mathematica Sinica,English Series 2010年第5期26卷 875-884页

作者： Jin hong kim Hee Kwon LEE Department of Mathematical Sciences Korea Advanced Institute of Science and Technology Guseong-dong

Let M be a positive quaternionic Kahler manifold of dimension 4m. We already showed that if the symmetry rank is greater than or equal to [m/2] ＋ 2 and the fourth Betti number b4 is equal to one, then M is isometric to HPm. The goal of this paper is to report that we can improve the lower bound of the symmetry rank by one for higher even-dimensional positive quaternionic Kahler manifolds. Namely, it is shown in this paper that if the symmetry rank of M with b4（M） = 1 is greater than or equal to m/2 ＋ 1 for m ≥ 10, then M is isometric to HPm. One of the main strategies of this paper is to apply a more delicate argument of Frankel type to positive quaternionic Kahler manifolds with certain symmetry rank.

关键词： positive quaternionic Kahler symmetry

Prospective comparison of prophylactic antibiotic use between intravenous moxifloxacin and ceftriaxone for high-risk patients with post-ERCP cholangitis

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Hepatobiliary & Pancreatic Diseases International 2017年第5期16卷 512-518页

作者： Nam Hee kim hong Joo kim Ki Bae Bang Department of Internal Medicine Sungkyunkwan University Kangbuk Samsung Hospital Department of Internal Medicine Dankook University Hospital

BACKGROUND: The use of prophylactic antibiotics before endoscopic retrograde cholangiopancreatography(ERCP) is recommended by all major international gastroenterological societies, especially in the presence of an obstructed biliary system. This study compared the occurrence rate of post-procedural complications, including cholangitis and septicemia between prophylactic intravenous moxifloxacin and ceftriaxone in patients with bile duct obstruction scheduled for therapeutic ***: From November 2013 to July 2015, 86 consecutive patients with biliary obstruction with one or more factors predicting benefits of antibiotic prophylaxis prior to ERCP were included in the current randomized open-label non-inferiority trial(Clinical *** identifier NCT02098486). Intravenous moxifloxacin(400 mg/day) or ceftriaxone(2 g/day)were given 90 minutes before ERCP, and were administered for more than 3 days if the patient developed symptoms and signs of cholangitis or septicemia. Recalcitrant cholangitis was defined as persistence of cholangitis for more than 5 days after ERCP or recurrence of cholangitis within 30 days after ***: Recalcitrant cholangitis occurred in 1(2.3%) and 2(4.8%) patients receiving intravenous moxifloxacin and ceftriaxone group, respectively(P=0.612). Septicemia was noted in1(2.3%) and 1(2.4%) patient in intravenous moxifloxacin and ceftriaxone group, respectively(P=1.0). The mean hospital stay was also not significantly different between the moxifloxacin and ceftriaxone groups(8.8±7.2 vs 9.1±9.4 days, P=0.867). Antibiotic resistance of the isolated pathogens by in vitro activity assay was noted in 1(2.3%) and 2(4.8%) patients in the moxifloxacin and ceftriaxone group, respectively(P=0.612). CONCLUSION: Intravenous moxifloxacin is not inferior to intravenous ceftriaxone for the prophylactic treatment of post-ERCP cholangitis and cholangitis-associated morbidity.

关键词： endoscopic retrograde cholangiopancreatography cholangitis moxifloxacin ceftriaxone recalcitrant cholangitis