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Journal of Magnesium and Alloys 2023年第5期11卷 1683-1696页

作者： Dong hee lee Gyo Myeong lee Sung Hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea

The effects of extrusion temperature on the microstructure and tensile properties of extruded AZ61 and AZ91 alloys are investigated by subjecting them to hot extrusion at 300 and 400℃.Although the average grain size of the extruded AZ61 alloy slightly increases from 9.5 to 12.6μm with increasing extrusion temperature,its resultant microstructural variation is *** contrast,the average grain size of the extruded AZ91 alloy significantly increases from 5.7 to 22.5μm with increasing extrusion temperature,and the type of Mg17Al12 precipitates formed in it changes from fine dynamic precipitates with a spherical shape to coarse static precipitates with a lamellar *** the extrusion temperature increases,the tensile yield strength of the extruded AZ61 alloy increases from 183 to 197 MPa while that of the extruded AZ91 alloy decreases from 232 to 224 *** tensile elongations of the extruded AZ61 and AZ91 alloys decrease with increasing extrusion temperature,but the degree of decrease is significant in the latter *** different extrusion temperature dependences of the tensile properties of the extruded AZ61 and AZ91 alloys are discussed in terms of their microstructural characteristics,strengthening mechanisms,and crack initiation sites.

关键词： Mg-Al-Zn alloys Extrusion temperature Precipitation Strengthening mechanism Tensile properties

Measurement of the time required for termites to pass each other in tunnels of different curvatures

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Insect Science 2013年第4期20卷 550-556页

作者： Seungwoo Sim Sang-hee lee Division of Fusion Convergence of Mathematical Sciences National Institute for Mathematical Sciences Daejeon South Korea

Subterranean termites construct complex tunnel networks for foraging. During travel in the tunnels, termites often encounter one another when passing in opposite directions. Such encounters are likely to affect the ＂movement efficiency,＂ which is the time required for a termite to travel a certain distance in a tunnel. In this study, we explored how individual-individual encounters affect movement efficiency in tunnels by measuring the time （v） taken by two termites to pass one another in tunnels of different curvatures. Artificial tunnels of 5 cm in length and variable widths （W） of 2, 3, or 4 mm were made. Tunnel distance （D） was 2, 3, 4, or 5 cm. When D had a higher value, curvature was lower. When W = 2, T was significantly shorter in the tunnel with D = 5 than in tunnels ofD = 2, 3, or 4, whereas v was statistically the same for D = 2, 3 and 4. When W = 3, r was shorter in the tunnel with D = 5 than for D = 3 and 4, while ~ was longer in the tunnel with D = 2 than for D = 3 and 4. When W = 4, r was longer in the tunnels with D = 2 and 3 than for D = 4 and 5. Based on these observations, 3 types of termite behavior were identified： biased walking, backward walking, and zigzag walking. We considered these results in relation to foraging efficiency.

关键词： individual-individual encounters movement efficiency termites tunnelcurvature turmel network

A study on the interference effects for tidal current power rotors

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Science China(Technological Sciences) 2010年第11期53卷 3094-3101页

作者： Chul-hee JO Kang-hee lee Jin-Young YIM Department of Naval Architecture & Ocean Engineering Inha University

Due to global warming, the need to secure an alternative resource has become more important nationally. With the high tidal range of up to 9.7 m on the west coast of Korea, numerous tidal current projects are being planned and constructed. To extract a significant quantity of power, a tidal current farm with a multi-arrangement is necessary in the ocean. The rotor, which initially converts the energy, is a very important component because it affects the efficiency of the entire system, and its performance is determined by various design variables. The power generation is strongly dependent on the size of the rotor and the incoming flow velocity. However, the interactions between devices also contribute significantly to the total power capacity. Therefore, rotor performance considering the interaction problems needs to be investigated for generating maximum power in a specific field. This paper documents a performance study of devices considering the interference between rotating rotors with axial, transverse and diagonal arrangements.

关键词： TCP (tidal current power) renewable energy interference effect rotor CWC (circulation water channel) CFD (computational fluid dynamics)

Comparative analyses of the venom components in the salivary gland transcriptomes and saliva proteomes of some heteropteran insects

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Insect Science 2022年第2期29卷 411-429页

作者： Kyungjae Andrew Yoon Woo-Jin Kim Seungki lee hee-Sun Yang Byoung-hee lee Si Hyeock lee Research Institute of Agriculture and Life Sciences Seoul National UniversitySeoulKorea EntoCode Co. SeoulKorea National Institute of Biological Resources Environmental Research ComplexIncheonKorea Department of Agricultural Biology Seoul National UniversitySeoulKorea

Salivary gland-specific transcriptomes of nine heteropteran insects with distinct feeding strategies (predaceous, hematophagous, and phytophagous) were analyzed and annotated to compare and identify the venom components as well as their expression profiles. The transcriptional abundance of venom genes was verified via quantitative real-time PCR. Hierarchical clustering of 30 representative differentially expressed venom genes from the nine heteropteran species revealed unique groups of salivary gland-specific genes depending on their feeding strategy. The commonly transcribed genes included a paralytic neurotoxin (arginine kinase), digestive enzymes (cathepsin and serine protease), an anti-inflammatory protein (cystatin), hexamerin, and an odorant binding protein. Both predaceous and hematophagous (bed bug) heteropteran species showed relatively higher transcription levels of genes encoding proteins involved in proteolysis and cytolysis, whereas phytophagous heteropterans exhibited little or no expression of these genes, but had a high expression of vitellogenin, a multifunctional allergen. Saliva proteomes from four representative species were also analyzed. All venom proteins identified via saliva proteome analysis were annotated using salivary gland transcriptome data. The proteomic expression profiles of venom proteins were in good agreement with the salivary gland-specific transcriptomic profiles. Our results indicate that profiling of the salivary gland transcriptome provides important information on the composition and evolutionary features of venoms depending on their feeding strategy.

关键词： hematophagous heteroptera phytophagous predaceous proteome analysis salivary gland-specific venom transcriptome analysis

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

Recent TCP(Tidal Current Power) projects in Korea

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Science China(Technological Sciences) 2010年第1期53卷 57-61页

作者： Chul hee JO Kang hee lee Yu Ho RHO School of Engineering Inha University253Yonghyun-DongNam-GuIncheon 402-751Republic of Korea Graduate School Department.of Naval Architecture & Ocean EngineeringInha University253Yonghyun-DongNam-GuIncheon 402-751Republic of Korea

Having strong current on the west coast with up to 10 m tidal range in Korea,there are many suitable and applicable locations for TCP(Tidal Current Power) application in *** only the west coast,but also the south west regions having narrow channels between islands creating fast ocean stream are suitable for *** first TCP application in Korea is 1 MW helical VAT(Vertical Axis Turbine) device installed in Wooldolmog area in *** first HAT(Horizontal Axis Turbine) TCP device of 25 KW was developed and installed in cooling water weir of Samchonpo power plant in ***,a 100 kW prototype HAT TCP device is being planned to be installed in Daebang strait in *** big project would be Inchon TCP farm of 200 MW on the west coast in *** consortium of 5 members was formed in April,*** site will be the largest TCP site in the *** paper describes recent TCP projects in Korea with background and environmental conditions of the projects.

关键词： TCP(Tidal Current Power) ocean energy renewable energy clean energy HAT(Horizontal Axis Turbine) VAT(Vertical Axis Turbine)

Controlled oxidation of Ni for stress-free hole transport layer of large-scale perovskite solar cells

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Nano Research 2019年第12期12卷 3089-3094页

作者： Seongha lee hee-Suk Roh Gill Sang Han Jung-Kun lee Department of Mechanical Engineering and Materials Science University of PittsburghPennsylvania 15261USA School of Advanced Materials Science and Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea

The effect of the residual thermal stress of NiO films on the performance of an inverted type perovskite solar cell was *** this study,NiO films were grown on fluorine dopedtin oxide(FTO)substrates of different surface roughness by thermally oxidizing Ni film and weretested as a hole transport layer for large-scale perovskite solar *** and simulation results show that it is very important tosuppress the appearance of the residual stress at the NiO-FTO in terface during the oxidation of the Ni film for effective hole extracti *** Ni oxidation on the flat FTO film produced in-plane compressive stress in the NiO film due to the Ni film volume *** led to theformation of defects including small *** residual stress and defects in creased leakage curre nt through the NiO film,preve ntingholes from being selectively collected at the NiO-perovskite ***,when Ni was deposited and oxidized on the rough surface,the residual stress of the NiO film was negligible and its inhere nt high resistance was ***-free NiO film is an excelle nt holetransport layer that stops the photogenerated electrons of the perovskite layer from moving to *** improvements in the structural andelectrical qualities of the NiO film by engirteering the residual stress reduce the carrier recombination and increase the power conversi onefficiency of the perovskite solar cells to 16.37%.

关键词： nickel oxidation surface roughness residual stress perovskite solar cells large scale processing

Using fluorescence surrogates to track algogenic dissolved organic matter(AOM) during growth and coagulation/flocculation processes of green algae

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Journal of Environmental Sciences 2019年第5期31卷 311-320页

作者： Quang Viet Ly Mi-hee lee Jin Hur Department of Environment & Energy Sejong University

Tracking the variation of the algogenic organic matter(AOM) released during the proliferation of green algae and subsequent treatment processes is crucial for constructing and optimizing control strategies. In this study, the potential of the spectroscopic tool was fully explored as a surrogate of AOM upon the cultivation of green algae and subsequent coagulation/flocculation(C/F) treatment processes using ZrCl_4 and Al_2(SO_4)_3. Fluorescence excitation emission matrix coupled with parallel factor analysis(EEM-PARAFAC) identified the presence of three independent fluorescent components in AOM, including protein-like(C1), fulvic-like(C2) and humic-like components(C3). Size exclusion chromatography(SEC) revealed that C1 in AOM was composed of large-sized proteins and aromatic amino acids. The individual components exhibited their unique characteristics with respect to the dynamic changes. C1 showed the highest correlation with AOM concentrations(R^2= 0.843) upon the C/F processes. C1 could also be suggested as an optical predictor for the formation of trihalomethanes upon the C/F processes. This study sheds a light for the potential application of the protein-like component(C1) as a practical surrogate to track the evolution of AOM in water treatment or wastewater reclamation systems involving Chlorella vulgaris green algae.

关键词： EEM-PARAFAC Enhanced coagulation Size exclusion chromatography Algal dissolved organic matter Trihalomethanes

Parameterization and Application of Storm Surge/Tide Modeling Using a Genetic Algorithm for Typhoon Periods

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Advances in Atmospheric Sciences 2011年第5期28卷 1067-1076页

作者： Sung Hyup YOU Yong hee lee Woo Jeong lee Marine Meteorology Division Observation Infrastructure Bureau/KMA Korea Forecast Research Laboratory National Institute of Meteorological Research/KMA Korea Global Environment System Research Laboratory National Institute of Meteorological Research/KMA Korea

A genetic algorithm was used to optimize the parameters of the two-dimensional Storm Surge/Tide Operational Model （STORM） to improve sea level *** genetic algorithm was applied to nine typhoons that affected the Korean Peninsula during *** following model parameters were used：the bottom drag coefficient,the background horizontal diffusivity,Smagorinski＇s horizontal viscosity,and the sea level pressure ***,the simulation results using the optimized,mean,and median parameter values improved sea level *** four estimated parameters improved the sea level prediction by 76% and 54% in the bias and root mean square error for Typhoon Kalmaegi （0807） in 2008,***-month simulations of February and August 2008 were also improved using the estimated *** study demonstrates that parameter optimization on STORM can improve sea level prediction.

关键词： genetic algorithm STORM sea level typhoon

Cutaneous ciliated cyst on the anterior neck in young women: A case report

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World Journal of Clinical Cases 2020年第19期8卷 4481-4487页

作者： Yon hee Kim Jihyoun lee Department of Pathology Soonchunhyang University Seoul HospitalSeoul 04401South Korea Department of Surgery Soonchunhyang University Seoul HospitalSeoul 04401South Korea

BACKGROUND A cutaneous ciliated cyst(CCC)is a rare,benign tumor in young female adults,which is usually found on the lower *** SUMMARY We found an uncommon location of CCC in the anterolateral cervical area and reviewed the literature.A 20-year-old female complained of a well-defined,painless,palpable mass that started several years *** mass was tense and movable and located at the anterolateral aspect of the *** showed a non-enhancing round *** excision biopsy was performed,and the cystic mass was revealed to be a *** The rare location of CCC can be found in anterior neck area,which should be another diagnostic option for mass on anterior neck.

关键词： Head and neck neoplasms Female Young adult Subcutaneous mass Mixed tumor Mullerian Case report