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Alloys Preparation of Ag Particles/Islands on Si Wafer by RF Magnetron Sputtering

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稀有金属材料与工程 2012年第S1期41卷 403-406页

作者： jae-Wung lee School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGA 30332-0245USA

In order to investigate the morphology change of Ag nano-particles/island film with the sputtering time and annealing temperature,Ag nano-particles/island films were sputtered on the silicon wafers by radio-frequency(RF)magnetron *** nano-particles/islands films were sputtered on Si wafer with different *** sputtering,the samples with Ag nano-particles/islands films were annealed at 100,200 and 400 o C for 1 h,*** spectrum was employed to examine the phase stability of Ag particles/island film after annealed at 400 o C for *** result showed that the Raman spectrum peak of Ag particles/island film with annealed at 400 o C was similar to that of pure *** electron microscope(SEM)was used to test the microstructures and morphology of the films with different *** further study the morphology change,atomic force microscope(AFM)was used to test surface morphology of the Ag particles/islands *** SEM and AFM results showed that the morphology of Ag nano-particles/island films were different with the increasing sputtering *** particles went through a dramatic change on the Si wafer surface,when sputtering time changed from 3 to 60 s,Ag particles diffused and agglomerated with the annealing temperature increasing.

关键词： Ag nano-particles/island film sputter anneal diffuse grow

Synergistically coupling of Ni–Fe LDH arrays with hollow Co–Mo sulfide nanotriangles for highly efficient overall water splitting

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Rare Metals 2024年第2期43卷 522-532页

作者： Yun jae lee Seung-Keun Park Department of Advanced Materials Engineering Chung-Ang UniversityAnseongGyeonggi-do17546Republic of Korea Department of Intelligent Energy and Industry Chung-Ang University84 Heukseok-ro Dongjak-guSeoul06974Republic of Korea Western Seoul Center Korea Basic Science Institute150 Bugahyeon-roSeodaemun-guSeoul03759Republic of Korea

Developing bifunctional catalysts that can catalyze both oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is pivotal to commercializing large-scale water ***,a novel hollow nanotriangle composed of NiFe LDH-CoMoS_(x) heterojunction(H-CMSx@NiFe LDH)is proposed as a highly efficient bifunctional electrocatalyst for both OER and *** fabricate a heterojunction system,ultra-thin nickel–iron layered double hydroxide(NiFe LDH)nanosheets are uniformly electrodeposited onto a metal–organic framework-derived hollow CoMoS_(x) *** strong coupling of CoMoS_(x) and NiFe LDH catalysts forms the intimate heterojunction interfaces to facilitate interfacial charge transfer,which is favorable to enhance the bifunctional catalytic ***,the large void of CoMoS_(x) nanotriangles and interconnected ultra-thin NiFe LDH nanosheets result in good electrolyte penetration and gas ***,the as-prepared H-CMSx@NiFe LDH on nickel foam(NF)exhibits an impressive catalytic activity and durability for OER and HER activities,delivering a current density of 100 mA·cm^(−2) at the small overpotentials of 214 and 299 mV in OER and HER,***,H-CMSx@NiFe LDH/NF proves to be an effective electrode for an alkaline electrolyzer,as a voltage of only 1.99 V is enough to achieve a current density voltage of only 1.99 V is enough to achieve a current density of 400 mA·cm^(−2) with no degradation in performance over 50 h.

关键词： Overall water splitting Metal-organic framework Molybdenum sulfide Layered double hydroxide Heterojunction

Impact of guideline adherence on the prognosis of Barcelona clinic liver cancer stage B hepatocellular carcinoma

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World Journal of Gastroenterology 2023年第47期29卷 6122-6137页

作者： Ji Eun Han Hyo Jung Cho jae Youn Cheong Sun Gyo Lim Min jae Yang choong-Kyun Noh Gil Ho lee Soon Sun Kim Department of Gastroenterology Ajou University School of MedicineSuwon 16499Gyeonggi-doSouth Korea

BACKGROUND Patients with Barcelona clinic liver cancer(BCLC)stage B hepatocellular carcinoma(HCC)are considerably heterogeneous in terms of tumor burden,liver function,and performance *** improve the poor survival outcomes of these patients,treatment approaches other than transarterial chemoembolization(TACE),which is recommended by HCC guidelines,have been adopted in realworld clinical *** hypothesize that this non-adherence to treatment guidelines,particularly with respect to the use of liver resection,improves survival in patients with stage B *** To assess guideline adherence in South Korean patients with stage B HCC and study its impact on *** A retrospective analysis was conducted using data from 2008 to 2016 obtained from the Korea Central Cancer *** with stage B HCC were categorized into three treatment groups,guideline-adherent,upward,and downward,based on HCC guidelines recommended by the Asian Pacific Association for the Study of the Liver(APASL),the European Association for the Study of the Liver(EASL),and the American Association for the Study of Liver Diseases(AASLD).The primary outcome was HCC-related deaths;tumor recurrence served as the secondary *** among the groups was compared using the Kaplan-Meier method and the log-rank *** of survival outcomes were identified using multivariable Cox regression *** In South Korea, over the study period from 2008 to 2016, a notable trend was observed in adherence to HCCguidelines. Adherence to the EASL guidelines started relatively high, ranging from 77% to 80% between 2008 and2012, but it gradually declined to 58.8% to 71.6% from 2013 to 2016. Adherence to the AASLD guidelines began at71.7% to 75.9% from 2008 to 2010, and then it fluctuated between 49.2% and 73.8% from 2011 to 2016. In contrast,adherence to the APASL guidelines remained consistently high, staying within the range of 90.14% to 94.5%throughout the entire study per

关键词： Hepatocellular carcinoma Barcelona clinic liver cancer stage B Guideline adherence Liver neoplasms Transarterial chemoembolization Liver resection

Nature Experience, Recreation Activity and Health Benefits of Visitors in Mountain and Urban Forests in Vienna, Zurich and Freiburg

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Journal of Mountain Science 2015年第6期12卷 1551-1561页

作者： Ju-hyoung lee Duk-jae lee Department of Forest Resources Faculty of Natural Resources Yeungnam University Department of Forest Resources College of Life & Environmental Science Daegu University

Mountain forests are managed for various purposes. Of these, recreation, leisure, and ecotourism are increasingly gaining prominence. Yet, with the development of new techniques for creating and managing urban forests, the perception of the public with regard to mountain forests and such urban forests is narrowing. For the purpose of this study, eight mountain forests and urban forests located in Zurich(Switzerland), Vienna(Austria) and Freiburg(Germany) were shortlisted. These places are renowned for their well-functioning management of mountain forests and creation of urban forests. As the study was to focus on the comparison of the perceptions of visitors in terms of their satisfaction in urban and mountain forests, the interview covered the following questions:(i) how satisfactory was the nature experience;(ii) how satisfactory were the outdoor recreational activities;(iii) whether the nature experiences influenced the mental and physical health of visitors. Responses thus received for each of the mountain forests and urban forests were assessed, with the total number of respondents being 247. Tourists visiting the selected areas were randomly chosen for a one-on-one interview survey. Results of the survey show that there is a clear perceptions of visitors differed between urban and mountain forests. However, the gap is insignificant or almost nonexistent with respect to satisfaction level of outdoor recreational activities and health benefits. These results are contrary to the findings of previous studies, which argued that the natural landscape of mountain areas is superior to other artificially built green spaces. Visitors did not perceive significant differences in outdoor recreational activities and health effects between the two spaces.

关键词： Europe Satisfaction Outdoor recreation Interview survey Preference

Prediction of Nitrogen Diffusivity in α-ferrite Based on Thermodynamics

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Journal of Iron and Steel Research International 2015年第8期22卷 743-745页

作者： jae-gil JUNG Seok-jae lee Light Metal Division Korea Institute of Materials Science Division of Advanced Materials Engineering Research Center for Advanced Materials Development Chonbuk National University

A thermodynamic based equation to predict the diffusivity of nitrogen in α-ferrite was investigated in consideration of the equilibrium nitrogen concentration. The temperature-dependent jump distance calculated from the lattice parameter of ferrite was used to derive the frequency factor as a function of temperature. The calculation accuracy for nitrogen diffusivity using the proposed thermodynamic based equation was improved by comparing the calculation results using previous empirical equations based on Arrhenius type relationship with measured diffusivity of nitrogen for α-ferrite at different temperatures.

关键词： nitrogen diffusivity ct-ferrite thermodynamics prediction

Development of analysis model for geometric error in turning processes

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Journal of Central South University 2011年第3期18卷 711-717页

作者： lee Mun-jae lee Choon-man Department of Mechanical Design and Manufacturing Engineering Changwon National University

A finite element model was established for analyzing the geometric errors in turning operations and a two-step analyzing process was proposed. In the first analyzing step, the cutting force and the cutting heat for the cutting conditions were obtained using the AdvantEdge. Also, the deformation of a workpiece was estimated in the second step using the ANSYS. The deformation was analyzed for a 150 mm-long workpiece at three different measuring points, such as 10, 70 and 130 mm from a reference point, and the amounts of the deformation were compared through experiments. /n the results of the comparison and analysis, the values obtained from these comparison and analysis represent similar tendencies. Also, it is verified that their geometric errors increase with the increase in temperature. In addition, regarding the factors that affect the deformation of a workpiecc, it can be seen that the geometric error in the lathe is about 15%, the error caused by the cutting force is about 10%, and the deformation caused by the heat is about 75%.

关键词： geometric error machining accuracy finite element analysis turning cutting force, cutting temperature

Effect of light scattering on the performance of a direct absorption solar collector

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Frontiers in Energy 2018年第1期12卷 169-177页

作者： Kwang Hyun WON Bong jae lee Department of Mechanical Engineering Korea Advanced Institute ofScience and Technology Daejeon 34141 South Korea

Recently, a solar thermal collector often employs nanoparticle suspension to absorb the solar radiation directly by a working fluid as well as to enhance its thermal performance. The collector efficiency of a direct absorption solar collector （DASC） is very sensitive to optical properties of the working fluid, such as absorption and scattering coefficients. Most of the existing studies have neglected particle scattering by assuming that the size of nanoparticle suspension is much smaller than the wavelength of solar radiation （i.e., Rayleigh scattering is applicable）. If the nanoparticle suspension is made of metal, however, the scattering cross-section of metallic nanoparticles could be comparable to their absorption cross-section depending on the particle size, especially when the localized surface plasmon （LSP） is excited. Therefore, for the DASC utilizing a plasmonic nanofluid supporting the LSP, light scattering from metallic particle suspension must be taken into account in the thermal analysis. The present study investigates the scattering effect on the thermal performance of the DASC employing plasmonic nanofluid as a working fluid. In the analysis, the Monte Carlo method is employed to numerically solve the radiative transfer equation considering the volume scatter- ing inside the nanofluid. It is found that the light scattering can improve the collector performance if the scattering coefficient of nanofluid is carefully engineered depending on its value of the absorption coefficient.

关键词： direct absorption solar collector plasmonicnanofluid light scattering

Effects of structure and electronic properties of D-π-A organic dyes on photovoltaic performance of dye-sensitized solar cells

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Journal of Energy Chemistry 2021年第3期30卷 208-216页

作者： Min-Woo lee jae-Yup Kim Hyung-Geun lee Hyun Gil Cha Duck-Hyung lee Min jae Ko Bio-Based Chemistry Research Center Advanced Convergent Chemistry DivisionKorea Research Institute of Chemical Technology(KRICT)Ulsan 44429Republic of Korea Department of Chemical Engineering Dankook UniversityYongin 16890Republic of Korea Department of Chemistry Sogang UniversitySeoul 04107Republic of Korea Department of Chemical Engineering Hanyang UniversitySeoul 04763Republic of Korea Institute of Nano Science and Technology Hanyang UniversitySeoul 04763Republic of Korea

Herein,we examine the performance of dye-sensitized solar cells containing five D-π-A organic dyes designed by systematic modification of π-bridge size and geometric *** dye has a simple push-pull structure with a triarylamino group as an electron donor,bithiophene-4,4-dimethyl-4 H-cyclopenta 1,2-b:5,4-b’]dithiophene(M11),4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophenethiophene(M12),thiophene-4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene(M13),4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene-benzene(M14),and 4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene(M15)units asπ-bridges,and cyanoacrylic acid as an electron acceptor/*** extension of theπ-bridge linkage favors wide-range absorption but,because of the concomitant molecular volume increase,hinders the efficient adsorption of dyes on the TiO_(2) film ***,higher loadings are achieved for smaller dye molecules,resulting in(i)a shift of the TiO_(2) conduction band edge to more negative values,(ii)a greater photocurrent,and(iii)suppressed charge recombination between the photoanode and the redox couple in the ***,under one-sun equivalent illumination(AM 1.5 G,100 mW/cm^(2)),the highest photovoltage,photocurrent,and conversion efficiency(η=7.19%)are observed for M15,which has the smallest molecular volume among M series dyes.

关键词： Dye-sensitized solar cells Donor-acceptor dyes Electron-rich unit Wide-range absorption Impedance spectroscopy

Characteristics of bifurcation and buckling load of space truss in consideration of initial imperfection and load mode

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第3期14卷 206-218页

作者： Su-deok SHON Seung-jae lee Kang-guk lee School of Architectural Engineering Korea University of Technology and Education1800 ChungjeolroCheonan ChungnamRepublic of Korea Research Center for Urban Affair Kyungil UniversityGyeongsan-city GyeongbukRepublic of Korea

This study investigated characteristics of bifurcation and critical buckling load by shape imperfection of space truss,which were sensitive to initial *** critical point and buckling load were computed by the analysis of the eigenvalues and determinants of the tangential stiffness *** two-free-nodes example and star dome were selected for the case study in order to examine the nodal buckling and global buckling by the sensitivity to the eigen buckling mode and the analyses of the influence,and characteristics of the parameters as defined by the load ratio of the center node and surrounding node,as well as rise-span ratio were *** sensitivity to the imperfection of the initial shape of the two-free-nodes example,which occurs due to snapping at the critical point,resulted in bifurcation before the limit point due to the buckling mode,and the buckling load was reduced by the increase in the amount of *** two sensitive buckling patterns of the numerical model are established by investigating the displaced position of the free nodes,and the asymmetric eigenmode greatly influenced the behavior of the imperfection shape whether it was at limit point or ***,the sensitive mode of the two-free-nodes example was similar to the in-extensional basis mechanism of a simplified *** star dome,which was used to examine the influence among several nodes,indicated that the influence of nodal buckling was greater than that of global buckling as the rise-span ratio was ***,global buckling is occurred with reaching bifurcation point as the value of load ratio was higher,and the buckling load level was about 50%-70% of load level at limit point.

关键词： Space truss Geometric nonlinearity Initial imperfection Snap-through Bifurcation Global buckling