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CORROSION AND MECHANICAL PROPERTIES OF Ti_3Al-Nb-Mo COMPOSITES FOR BIO-AND ENVIRONMENTAL MATERIALS PREMRED By SELF-PROMGATING HIGH TEMPERATURE REACTION

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Acta Metallurgica Sinica(English Letters) 2002年第2期15卷 149-153页

作者： y.choi N.I.Baik H.D.Cho S.I.Hong Department of Metallurgical and Materials Engineering Sunmoon University#100 Kalsan-RiTangjeoung-MyunAsanChungnam336-840Korea Department of Environmental Engineering Sunmoon University#100 Kalsan-RiTangjeoung-MyunAsanChungnam336-840Korea Department of Metallurgical Engineering Chungnam National UniversityDaejeon305-764Korea Manuscript received 31 July 2001

Ti3 AL-Nb-Mo composites were prepared by SHS using initial powder mixtures of Ti-Al-Nb-Mo and their corrosion and mechanical properties were studied to develop bioand environmental materials. The composites reached 99.8% of theoretical density after the direct consolidation. The composites shows equiaxed primary a2 in a matrix of fine secondary a2 plates and ordered 82 (Bo) forming a basket weave structure. The strain rate sensitivity (m = dlnσ/dlne) at 2% strain is 0.008. Corrosion potential and corrosion rate of the composites formed by SHS were -151. 5m VSHE and 5. 72× 10^(-8)A/cm2 for Ti3 Al-10Nb-1. 5Mo and - 138.4m VSHE and 4. 12×10^(-8)cm2 for Ti3 Al-12Nb-1.5Mo in a 50% NaOH-10%FeCI3 solution, respectively. Corrosion resistance decreased with niobium content in the composites and chloride content in the aqueous solution. Selective corrosion of a2 phase in a matrix occurred in the corrosion environment which suggests that the corrosion potential and rate changes are related to the niobium content and Q2 phase in a matrix.

关键词： Ti3 Al alloy corrosion strength SHS

Remote Observations in China’s Ramsar Sites: Wetland Dynamics, Anthropogenic Threats, and Implications for Sustainable Development Goals

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Journal of Remote Sensing 2021年第1期2021卷 319-331页

作者： D.Mao Z.Wang y.Wang C.-y.choi M.Jia M.V.Jackson R.A.Fuller Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China National Earth System Science Data Center BeijingChina Department of Natural Resources Sciences University of Rhode IslandKingstonRI 02881USA School of Environmental Science and Engineering College of EngineeringSouthern University of Science and TechnologyShenzhen 518055China School of Biological Sciences The University of QueenslandBrisbaneAustralia

The Ramsar Convention on Wetlands is an international framework through which countries identify and protect important *** Ramsar wetlands are under substantial anthropogenic pressure worldwide,and tracking ecological change relies on multitemporal data ***,we evaluated the spatial extent,temporal change,and anthropogenic threat to Ramsar wetlands at a national scale across China to determine whether their management is currently *** analyzed Landsat data to examine wetland dynamics and anthropogenic threats at the 57 Ramsar wetlands in China between 1980 and *** reveal that Ramsar sites play important roles in preventing wetland loss compared to the dramatic decline of wetlands in the surrounding ***,there are declines in wetland area at 18 Ramsar *** those,six lost a wetland area greater than 100 km^(2),primarily caused by agricultural *** expansion of anthropogenic land covers occurred within 43(75%)Ramsar sites,and anthropogenic threats from land cover change were particularly notable in eastern *** pond expansion and Spartina alterniflora invasion were prominent threats to coastal Ramsar *** observations within China’s Ramsar sites,which in management regulations have higher levels of protection than other wetlands,can help track progress towards achieving United Nations Sustainable Development Goals(SDGs).The study findings suggest that further and timely actions are required to control the loss and degradation of wetland ecosystems.

关键词： Sustainable threat wetland

Effects of Dietary Proteins of Proso, Japanese and Korean Foxtail Millets on Lipid Metabolism and Type-2 Diabetes in Rats and Mice

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食品科学 2005年第5期26卷 220-224页

作者： Naoyuki Nishizawa y-y.choi y.Miyakoshi D.Sato T.Togawa T.Nagasawa y.Ito M Watanabe M.Sato M-R choi Iwate University Department of Agro-BiosciencesFaculty of AgricultureMoriokaIwate 020-8550Japan National Agricultural Research Center for Tohoku Reg. MoriokaIwateJapan yosu National University YeosuRepublic of Korea

Summary We examined the effects of dietary Japanese millet protein(JMP)and Korean foxtail millet protein(KFMP)on lipid metabolism and type 2 diabetes in rats and *** type 2 diabetic rats were fed with JMP for 20 days,plasma glucose levels lowered,whereas those of HDL-cholesterol and adiponectin rose significantly compared to the control *** when type 2 diabetic mice were fed with KFMP for 20 days,plasma levels of insulin lowered greatly,whereas those of HDL-cholesterol and adiponectin rose remarkably compared to control *** the role of adiponectin,insulin and HDL-cholesterol in diabetes and atherosclerosis or obesity,it seemed likely that JMP and KFMP might improve insulin sensitivity and cholesterol metabolism through an increase in adiponectin ***,these proteins might serve as another beneficial food component in obesity-related dis-eases such as type 2 diabetes and cardiovascular diseases.

关键词： JMP Japanese

微钙化和瘤周水肿预测接受新辅助化疗的Luminal型乳腺癌病人的生存结果

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国际医学放射学杂志 2022年第5期 605-606页

作者： B.R.Kwon S.U.Shin S.y.Kim y.choi N.Cho S.M.Kim 文凤

摘要对于接受新辅助化疗（NAC）的Luminal型乳腺癌病人的影像学表现与生存率的关系知之甚少。目的确定影像学（MRI、US和乳腺X线摄影）和临床病理变量在预测接

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Promising therapeutic potential of tumor suppressor microRNAs for malignant pleural mesothelioma

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Journal of Cancer Metastasis and Treatment 2022年第1期8卷 91-101页

作者： Shivani Dixit Agnes y.choi Anand Singh Karthik Pittala Nathan Pruett Chuong D.Hoang Thoracic Surgery Branch National Cancer InstituteNational Institutes of HealthBethesdaMD 20892USA

Malignant pleural mesothelioma(MPM)is an aggressive and recalcitrant surface neoplasm that defies current multimodality ***(miRNAs)are small noncoding RNAs that epigenetically regulate multiple gene networks and cellular *** cancer,miRNA dysregulation is associated with tumorigenesis,with tumor suppressor miRNAs underexpressed or lost,while oncogenic miRNAs are ***,miRNAs have emerged as potential therapeutic *** loss of tumor suppressors predominates the pathophysiology of MPM,re-expressing tumor suppressor miRNAs could be an effective therapeutic *** review highlights the most promising MPM-specific tumor suppressor miRNAs that could be developed into novel therapeutics,the supporting data,and what is known about their molecular mechanism(s).

关键词： Malignant pleural mesothelioma microRNA tumor suppressor therapeutic

Synthetic brochosomes:Design,synthesis,and applications

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Nano Research 2024年第2期17卷 734-742页

作者： Lin Wang Jinsol choi Tak-Sing Wong Department of Mechanical Engineering The Pennsylvania State UniversityUniversity ParkPA 16802USA Materials Research Institute The Pennsylvania State UniversityUniversity ParkPA 16802USA Department of Biomedical Engineering The Pennsylvania State UniversityUniversity ParkPA 16802USA

Brochosomes,which are nanoscopic buckyball-shaped granules produced by leafhoppers,are one of the most intricate structures discovered in *** functions of brochosomes have been proposed but only a few have been experimentally validated due to the challenge of fabricating their synthetic *** in micro-and nanofabrication have recently led to the emergence of synthetic brochosomes,opening up new possibilities for innovative *** review explores the early discovery of natural brochosomes and their geometrical features,followed by the recent progress in fabricating synthetic brochosomes and their *** on future applications and challenges in the scalable manufacturing of synthetic brochosomes are discussed.

关键词： synthetic brochosomes leafhopper antireflection superhydrophobicity surface-enhanced Raman scattering photocatalyst energy harvesting

Correlation between hydration properties and electrochemical performances on Ln cation size effect in layered perovskite for protonic ceramic fuel cells

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Journal of Energy Chemistry 2024年第1期88卷 1-9,I0001页

作者： Inhyeok Cho Jiwon yun Boseok Seong Junseok Kim Sun Hee choi Ho-Il Ji Sihyuk choi Department of Mechanical Engineering Kumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Department of Aeronautics Mechanical and Electronic Convergence EngineeringKumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Center for Energy Materials Research Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Center for Hydrogen and Fuel Cell Research Clean Technology Research DivisionKorea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Department of Energy and Environmental Engineering University of Science and TechnologySeoul 02792Republic of Korea Nanomaterials Science and Engineering Korea University of Science and Technology(UST)KIST CampusSeoul 02792Republic of Korea

PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceramic fuel cells(PCFCs). The chemical formula for Pr BSCF is AA'B_(2)O_(5+δ), with Pr(A-site) and Ba/Sr(A'-site) alternately stacked along the c-axis. Due to these structural features, the bulk oxygen ion diffusivity is significantly enhanced through the disorder-free channels in the PrO layer;thus, the A site cations(lanthanide ions) play a pivotal role in determining the overall electrochemical properties of layered perovskites. Consequently, previous research has predominantly focused on the electrical properties and oxygen bulk/surface kinetics of Ln cation effects,whereas the hydration properties for PCFC systems remain unidentified. Here, we thoroughly examined the proton uptake behavior and thermodynamic parameters for the hydration reaction to conclusively determine the changes in the electrochemical performances depending on LnBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(LnBSCF,Ln=Pr, Nd, and Gd) cathodes. At 500 ℃, the quantitative proton concentration of PrBSCF was 2.04 mol% and progressively decreased as the Ln cation size decreased. Similarly, the Gibbs free energy indicated that less energy was required for the formation of protonic defects in the order of Pr BSCF ydration properties and electrochemical performances in LnBSCF cathodes, PCFC single cell measurements and analysis of the distribution of relaxation time were further investigated.

关键词： Protonic ceramic fuel cell Cathode Triple ionic and electronic conductor Hydration property Proton uptake Gibbs free energy

Development of vehicle-recognition method on water surfaces using LiDAR data:SPD^(2)(spherically stratified point projection with diameter and distance)

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Defence Technology（防务技术） 2024年第6期36卷 95-104页

作者： Eon-ho Lee Hyeon Jun Jeon Jinwoo choi Hyun-Taek choi Sejin Lee The Department of Mechanical Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea Ocean System Engineering Research Division Korea Research Institute of Ships and Ocean Engineering(KRISO)Daejeon 34103Republic of Korea The Division of Mechanical&Automotive Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea

Swarm robot systems are an important application of autonomous unmanned surface vehicles on water *** monitoring natural environments and conducting security activities within a certain range using a surface vehicle,the swarm robot system is more efficient than the operation of a single object as the former can reduce cost and save *** is necessary to detect adjacent surface obstacles robustly to operate a cluster of unmanned surface *** this purpose,a LiDAR(light detection and ranging)sensor is used as it can simultaneously obtain 3D information for all directions,relatively robustly and accurately,irrespective of the surrounding environmental *** the GPS(global-positioning-system)error range exists,obtaining measurements of the surface-vessel position can still ensure stability during platoon *** this study,a three-layer convolutional neural network is applied to classify types of surface *** aim of this approach is to redefine the sparse 3D point cloud data as 2D image data with a connotative meaning and subsequently utilize this transformed data for object classification ***,we have proposed a descriptor that converts the 3D point cloud data into 2D image *** use this descriptor effectively,it is necessary to perform a clustering operation that separates the point clouds for each *** developed voxel-based clustering for the point cloud ***,using the descriptor,3D point cloud data can be converted into a 2D feature image,and the converted 2D image is provided as an input value to the *** intend to verify the validity of the proposed 3D point cloud feature descriptor by using experimental data in the ***,we explore the feasibility of real-time object classification within this framework.

关键词： Object classification Clustering 3D point cloud data LiDAR(light detection and ranging) Surface vehicle

Rapid monitoring of indoor airborne influenza and coronavirus with high air flowrate electrostatic sampling and PCR analysis

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 73-85页

作者： Sanggwon An Sangsoo choi Hyeong Rae Kim Jungho Hwang School of Mechanical Engineering Yonsei UniversitySeoul 02876Republic of Korea Gas Metrology Group Korea Research Institute of Standards and Science(KRISS)Daejeon 34113Republic of Korea

The World Health Organization has raised concerns about the possibility of airborne transmission in enclosed and poorly ventilated ***,rapid monitoring of airborne viruses is necessary in multi-use facilities with dense ***,an electrostatic air sampler(250 L/min)was developed in this work to obtain indoor viral aerosol samples for analysis via the Polymerase Chain Reaction(PCR).Aerosol tests with H1N1 and HCoV-229E were performed to evaluate the sample collection *** analysis,along with another aerosol test,was conducted to evaluate the recovery of the virus particles collected by the *** laboratory tests,our electrostatic sampler obtained viral samples that were detectable by PCR under the simulated viral pandemic scenario(3000 RNA copies per cubic meter of air)within 40 *** resulting cycle threshold(C)values were 35.07 and 37.1 for H1N1 and HCoV-229E,*** the performance evaluation in the laboratory,field tests were conducted in a university classroom from October 28 to December 2,*** A and HCoV-229E were detected in two air samples,and the corresponding C,values were 35.3 and *** PCR results are similar to those obtained from laboratory tests,considering the simulatedviralpandemic scenario.

关键词： Airborne virus Electrostatic sampler Rapid monitoring Indoor environment Field test