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Laser-assisted Grinding Wheel Dressing (Ⅱ)-Experimental Researches

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Journal of Materials Science & Technology 2003年第z1期19卷 167-168页

作者： Ming CHEN Fanghong sun Youngmoon lee Seunghan YANG Jongchan lee School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200030 China School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200030 China School of Mechanical Engineering Kyungpook National University Daegu 702-701 Korea School of Mechanical Engineering Kyungpook National University Daegu 702-701 Korea School of Mechanical Engineering Kumoh National University of Technology Kumi Kyungpook 730-701 Korea

Most of the mechanical dressing technologies for resin bonded superabrasive grinding wheels are time consumingand costly. Based on the outcomes of the simulations in the previous study, this paper demonstrates the comprehensive researches on the laser-assisted dressing process control, grinding wheel topography reconfiguration by 3Dlaser scanning technology and analyses of grinding temperature. The synthesized parameter incorporates the laserdressing process parameters and can be used to the process control. In order to evaluate the laser-assisted dressingeffectiveness, the newly developed non-contact laser measuring system based on the principle of the triangulationwas used. Grain protrusion height and intergrain spacing can characterize the grinding wheel surface. A series ofgrinding tests with the laser-assisted dressed grinding wheel and mechanically dressed grinding wheel were conductedfor comparison. The results proved the feasibility of laser-assisted dressing for resin bonded superabrasive grindingwheels and revealed the importance of choosing appropriate laser dressing parameters.

关键词： Grinding wheel topography, Laser, Dressing, Grinding

Development of Non-Dissipative Direct Time Integration Method for Structural Dynamics Application

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Computer Modeling in Engineering & Sciences 2019年第1期118卷 41-89页

作者： sun-Beom Kwon Jae-Myung lee Department of Naval Architecture and Ocean Engineering Pusan National UniversityJangjeon-DongGeumjeong-GuBusan 609-735Korea.

A direct time integration scheme based on Gauss-Legendre quadrature is proposed to solve problems in linear structural *** proposed method is a oneparameter non-dissipative *** stability,accuracy,and dispersion characteristics are achieved using appropriate values of the *** proposed scheme has second-order accuracy with and without physical ***,its stability,accuracy,and dispersion are *** addition,its performance is demonstrated by the two-dimensional scalar wave problem,the single-degree-of-freedom problem,two degrees-of-freedom spring system,and beam with boundary *** wave propagation problem is solved in the high frequency wave regime to demonstrate the advantage of the proposed *** the proposed scheme is applied to solve the wave problem,more accurate solutions than those of other methods are obtained by using the appropriate value of the *** the single-degree-offreedom system,two degrees-of-freedom system,and the time responses of beam,the proposed scheme can be used effectively owing to its high accuracy and lower computational cost.

关键词： Structural dynamics finite elements direct time integration Gauss-Legendre quadrature non-dissipative scheme.

Supersonically sprayed self-aligne d rGO nanosheets and ZnO/ZnMn_(2)O_(4)nanowires for high-energy and high-power-density supercapacitors

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Journal of Materials Science & Technology 2023年第6期137卷 193-204页

作者： Chanwoo Park Edmund samuel Byeong-Yeop Kim Seongpil An Hae-Seok lee sam S.Yoon School of Mechanical Engineering Korea UniversitySeoul 02841Republic of Korea Energy Environment Policy and Technology Graduate School of Energy and Environment(KU-KIST Green School)Korea UniversityRepublic of Korea SKKU Advanced Institute of Nanotechnology(SAINT)and Department of Nano Engineering Sungkyunkwan University(SKKU)Suwon 16419Republic of Korea

Core-shell-type bimetallic oxide and carbon composites comprising zinc oxide(ZnO)nanospheres and zinc manganese oxide(ZnMn_(2)O_(4))nanowires were produced by a hydrothermal method,and supersoni-cally sprayed together with reduced graphene oxide(rGO)nanosheets onto Ni foil to fabricate flexible *** supersonic impact facilitated the exfoliation of the rGO nanosheets,thereby increasing the surface area and adhesion of the composite particles to the *** rGO nanosheets were vertically aligned during the supersonic impact and formed localized zones,enabling optimal accommodation of the ZnO/ZnMn_(2)O_(4)*** localization,with the addition of rGO,reduced the agglomeration of ZnO/ZnMn_(2)O_(4)*** molar concentration of MnSO_(4)used in the synthesis of ZnO/ZnMn_(2)O_(4)was varied from 0.05 to 0.15 mol/L to determine the optimal MnSO_(4)concentration that would result in the highest energy storage *** unique nanostructure of ZnO/ZnMn_(2)O_(4)and the self-alignment of rGO sheets facilitated a favorable environment for high energy storage capability with a specific capaci-tance of 276.3 mF·cm^(−2)at a current density of 0.5 mA·cm^(−2)and an energy density of 98.2μWh·cm^(−2)at a power density of 1600μW·cm^(−2).The width of the potential window was increased to 1.2 V,imply-ing a significant increase in the energy storage capability of the *** retention of 88%was achieved after 10,000 charge/discharge cycles for the supercapacitor fabricated using an optimal MnSO_(4)concentration(0.10 mol/L)during the composite synthesis.

关键词： ZnO/ZnMn_(2)O_(4)nanowires rGO nanosheets Hydrothermal method Supersonic spraying Supercapacitor

Septal patterns in Agetolites from the Xiazhen Formation(Upper Ordovician) at Zhuzhai,Yushan County,Jiangxi Province,South China

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Science China Earth Sciences 2014年第2期57卷 247-257页

作者： sun Ning DongJin lee WANG XunLian School of Earth Sciences and Resources China University of Geosciences Department of Earth and Environmental Sciences Andong National University College of Earth Sciences Jilin University

Patterns of septal insertion were analyzed in three species of Agetolites from the Upper Ordovician in Yushan County, Jiangxi Province of China. Agetolites is a peculiar coral possessing features of both tabulate （e.g., mural pores） and rugose corals （e.g., welldeveloped septa）. Septal patterns have long been considered to be indicative of the origin of corals, and the pattern of septal insertion in Agetolites has been known to be typical of rugosans. This study, however, reveals that the patterns in Ageto lites are rather random and cannot be an indication of its rugosan affinity. It is suggested that Agetolites probably has a closer phylogenetic relation with tabulates than with either rugosans or scleractinians. Two insertion patterns of the first six septa were detected （Types I and II）. Type I is interpreted as scleractinian pattern whereas Type II as typical pattern of rugosans. Types 1 and 2 are septal patterns of the second stage recognized in this study. Type 1 insertion occurs in six sectors located in the center of each interseptal space, suggesting scleractinian pattern of insertion. Type 2 insertion occurs in four sectors that are comparable with alar and counter sectors in rugose corals. Four patterns of the third （Types AD） and fourth stages （Types ad） of septal insertion have also been recognized in Agetolites. Type A only occurs in two adjacent sectors possibly due to the in completeness of septal development. Type B presents rugosan pattern. Types C and D resemble scleractinian pattern in most aspects. Types a, b, and c present no clear attribution to rugosan or scleractinian pattern probably due to the incompleteness of septal development whereas Type d is observable in rugose corals.

关键词： Agetolites septal patterns Tabulata Upper Ordovician

Estimation of plasma density perturbation from dusty plasma injection by laser irradiation on tungsten target in DiPS

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Plasma Science and Technology 2020年第4期22卷 90-96页

作者： In Je KANG Min-Keun BAE In sun PARK Min Ji lee Kyu-sun CHUNG Department of Electrical Engineering Hanyang UniversitySeoul 133791Republic of Korea Plasma Technology Research Center National Fusion Research InstituteGunsan 54004Republic of Korea

To investigate the interaction of dusty plasma with magnetized plasmas at divertor plasma simulator,radial profiles of plasma density(ne)and electron temperature were measured in terms of plasma discharge currents and magnetic flux intensity by using a fast scanning probes system with triple *** plasma with dusts(a generation rate of 3μg s-1 and a size of 1–10μm)was produced via interactions between a high-power laser beam and a full tungsten *** ne increases,the scale of the effects of dusty plasma injection on magnetized plasmas was ***,the duration of transient fluctuation was *** numerical estimation of plasma density perturbation due to dusty plasma injection,the result was 10%at a core region of the magnetized plasma with ne of(2–5)×10^11 cm^-3 at steady state condition.

关键词： plasma density perturbation dusty plasma tungsten dust DiPS

ZIF-67@Cellulose nanofiber hybrid membrane with controlled porosity for use as Li-ion battery separator

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Journal of Energy Chemistry 2021年第1期30卷 170-180,I0006页

作者： Xiuxuan sun Wangwang Xu Xiuqiang Zhang Tingzhou Lei sun-Young lee Qinglin Wu School of Renewable Natural Resources Louisiana State University AgCenterBaton RougeLA 70803United States Key Biomass Energy Laboratory of Henan Province Zhengzhou 450008HenanChina Forest Products Department National Institute of Forest Science57 HoegiroDongdaemun-guSeoul 02455Republic of Korea

Zeolitic imidazolate framework-67(ZIF-67) was synthesized on the surface of cellulose nanofibers(CNFs)in methonal to address the problems of unhomogeneous pore size and pore distribution of pure CNF membrane.A combination of Energy Dispersive X-Ray Spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS) and X-ray powder diffraction(XRD) patterns were used to determine the successful synthesis of ZIF-67@*** size of the ZIF-67 particles and pore size of the ZIF-67@CNF membrane were50-200 nm and 150-350 nm, *** prepared ZIF-67@CNF membrane exhibited excellent thermal stability,lower thermal shrinkage and high surface *** discharge capacity retention of the Li-ion batteries(LIBs) made with ZIF-67@CNF,glass fiber(GF),CNF and commercial polymer membranes after 100 th cycle at 0.5 C rate were 88.41%,86.22%,83.27%,and 81.03%,*** with ZIF-67@CNF membrane exhibited a better rate capability than these with other *** damage of porous structure or peel-off of ZIF-67 was observed in the SEM images of ZIF-67@CNF membrane after100 th *** improved cycling performance,rate capability,and good electrochemical stability implied that ZIF-67@CNFs membrane can be considered as a good alternative LIB separator.

关键词： Cellulose nanofibers ZIF-67 Li-ion battery Membrane property Battery performance

Longwave infrared multispectral image sensor system using aluminum-germanium plasmonic filter arrays Noor E

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Nano Research 2023年第7期16卷 10018-10025页

作者： Karishma Shaik Bryce Widdicombe Dechuan sun sam E John Dongryeol Ryu Ampalavanapillai Nirmalathas Ranjith R Unnithan Department of Electrical and Electronic Engineering University of MelbourneParkvilleVIC 3010Australia Department of Biomedical Engineering University of MelbourneParkvilleVIC 3010Australia Department of Infrastructure Engineering University of MelbourneParkvilleVIC 3010Australia

A multispectral camera records image data in various wavelengths across the electromagnetic spectrum to acquire additional information that a conventional camera fails to *** the advent of high-resolution image sensors and color filter technologies,multispectral imagers in the visible wavelengths have become popular with increasing commercial viability in the last ***,multispectral imaging in longwave infrared(LWIR,8-14μm)is still an emerging area due to the limited availability of optical materials,filter technologies,and high-resolution *** from LWIR multispectral cameras can capture emission spectra of objects to extract additional information that a human eye fails to capture and thus have important applications in precision agriculture,forestry,medicine,and object *** this work,we experimentally demonstrate an LWIR multispectral image sensor with three wavelength bands using optical elements made of an aluminum(Al)-based plasmonic filter array sandwiched in germanium(Ge).To realize the multispectral sensor,the filter arrays are then integrated into a three-dimensional(3D)printed wheel stacked on a low-resolution monochrome thermal *** prototype device is calibrated using a blackbody and its thermal output has been enhanced with computer vision *** applying a state-of-theart deep learning method,we have also reconstructed multispectral images to a better spatial ***,our work demonstrates a versatile spectral thermography technique for detecting target signatures in the LWIR range and other advanced spectral analyses.

关键词： infrared plasmonics germanium(Ge) aluminum(Al) thermal optics longwave infrared(LWIR)multispectral system

Simulations of the Dependence of Gas Physical Parameters on Deposition Variables during HFCVD Diamond Films

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Journal of Materials Science & Technology 2006年第5期22卷 599-604页

作者： Aiying WANG Kwangryeol lee Chao sun Lishi WEN Future Technology Research Division Korea Institute of Science and Technology P.O.Box 131 CheongryangSeoul 130-650 Korea Plasma Lab J＆L Tech. Co. Ltd Siheung city Kyunggi-do 2185-7 Korea Department of Surface Engineering of Materials Institute of Metal Research Chinese Academy of SciencesShenyang 110016 China

During the growth of the hot filament chemical vapor deposition （HFCVD） diamond films, numerical simulations in a 2-D mathematical model were employed to investigate the influence of various deposition parameters on the gas physical parameters, including the temperature, velocity and volume density of gas. It was found that, even in the case of optimized deposition parameters, the space distributions of gas parameters were heterogeneous due primarily to the thermal blockage come from the hot filaments and cryogenic pump effect arisen from the cold reactor wall. The distribution of volume density agreed well with the thermal round-flow phenomenon, one of the key obstacles to obtaining high growth rate in HFCVD process. In virtue of isothermal boundary with high temperature or adiabatic boundary condition of reactor wall, however, the thermal roundflow was profoundly reduced and as a consequence, the uniformity of gas physical parameters was considerably improved, as identified by the experimental films growth.

关键词： Gas physical parameters Simulations Diamond films HFCVD

Variability and trends of near-surface wind speed over the Tibetan Plateau:The role played by the westerly and Asian monsoon

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Advances in Climate Change Research 2024年第3期15卷 525-536页

作者： Gang-Feng ZHANG Cesar AZORIN-MOLINA Deliang CHEN Tim RMCVICAR Jose AGUIJARRO Kai-Qiang DENG Lorenzo MINOLA Jaeyeon lee Seok-Woo SON Heng MA Pei-Jun SHI State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China Engineering Center of Desertification and Blown-Sand Control of Ministry of Education Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Key Laboratory of Environmental Change and Natural Disaster of Ministry of Education Beijing Normal UniversityBeijing 100875China Centro de Investigaciones Sobre Desertificaci'on Consejo Superior de Investigaciones Cientı'ficas(CIDECSIC-UV-Generalitat alenciana)ClimateAtmosphere and Ocean Laboratory(Climatoc-Lab)Moncada 46113Spain Regional Climate Group Department of Earth SciencesUniversity of GothenburgGothenburg 40530Sweden CSIRO Environment CanberraACT 2600Australia Australian Research Council Centre of Excellence for Climate Extremes CanberraACT 2600Australia State Meteorological Agency Balearic Islands OfficePalma de Mallorca 07015Spain School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 519082China Interuniversity Department of Regional and Urban Studies and Planning(DIST) Politecnico and University of TurinTurin 10125Italy School of Earth and Environmental Sciences Seoul National UniversitySeoul 08826South Korea Atmospheric and Oceanic Sciences Program Princeton UniversityPrinceton NJ 08544USA Geophysical Fluid Dynamics Laboratory NOAAPrinceton NJ 08544USA

Near-surface wind speed exerts profound impacts on many environmental issues,while the long-term(≥60 years)trend and multidecadal variability in the wind speed and its underlying causes in global high-elevation and mountainous areas(e.g.,Tibetan Plateau)remain largely ***,by examining homogenized wind speed data from 104 meteorological stations over the Tibetan Plateau for 1961-2020 and ERA5 reanalysis datasets,we investigated the variability and long-term trend in the near-surface wind speed and revealed the role played by the westerly and Asian *** results show that the homogenized annual wind speed displays a decreasing trend(-0.091 m s^(−1)per decade,p<0.05),with the strongest in spring(-0.131 m s^(−1)per decade,p<0.05),and the weakest in autumn(-0.071 m s^(−1)per decade,p<0.05).There is a distinct multidecadal variability of wind speed,which manifested in an prominent increase in 1961-1970,a sustained decrease in 1970-2002,and a consistent increase in *** observed decadal variations are likely linked to large-scale atmospheric circulation,and the correlation analysis unveiled a more important role of westerly and East Asian winter monsoon in modulating near-surface wind changes over the Tibetan *** potential physical processes associated with westerly and Asian monsoon changes are in concordance with wind speed change,in terms of overall weakened horizontal air flow(i.e.,geostrophic wind speed),declined vertical thermal and dynamic momentum transfer(i.e.,atmospheric stratification thermal instability and vertical wind shear),and varied Tibetan Plateau *** indicates that to varying degrees these processes may have contributed to the changes in near-surface wind speed over the Tibetan *** study has implications for wind power production and soil wind erosion prevention in the Tibetan Plateau.

关键词： Tibetan Plateau Wind speed Decadal change Atmospheric circulation Physical processes