检索结果-南通市图书馆

Effect of Eu3+,Bi3+,and Li+ doping on luminescent property of GdNbO4

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第1期42卷 66-75页

作者： s.W.Wi Y.s.lee Department of Physics and Integrative Institute of Basic sciences Soongsil University

We investigated the emission properties of Eu3+-doped GdNbO4-based oxide phosphors,aiming at improving the Eu3+emission by codoping of Bi3+and Li+.Eu3+singly doped,Eu3+and Bi3+doubly doped,and Eu3+,Bi3+,and Li+triply doped GdNbO4were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu3+in the singly doped samples are significantly improved by the codoping of Bi3+,mainly due to the energy transfer from Bi3+to Eu3+.The additional codoping of Li+is found to increase the Eu3+emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu3+in GdNbO4does not change significantly with the codoping of Bi3+and Li+.Our results indicate that Li+doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO4phosphors.

关键词： Eu 3+ GdNbO 4 Codoping of Li + Photoluminescence sensitizer Rare earths

Mathematical modeling and simulations of stress mitigation by coating polycrystalline particles in lithium-ion batteries

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： N.IQBAL J.CHOI s.F.sHAH C.lee s.lee Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation Ni-rich LiNixMnyCo_(z)O_(2)(x>0.8)(NMC)

superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.T.Jeong s.W.lee W.J.Kim Department of Materials science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy superplasticity severe plastic deformation Grain size Grain growth

Enhancing Identity Protection in Metaverse-Based Psychological Counseling system

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第1期78卷 617-632页

作者： Jun lee Hanna lee seong Chan lee Hyun Kwon Department of Game software Hoseo UniversityAsan-si31499Korea Yatav Enter Seoul04799Korea Department of Artificial Intelligence and Data science Korea Military AcademySeoul01805Korea

Non-face-to-face psychological counseling systems rely on network technologies to anonymize information regard-ing client ***,these systems often face challenges concerning voice data leaks and the suboptimal communication of the client’s non-verbal expressions,such as facial cues,to the *** study proposes a metaverse-based psychological counseling system designed to enhance client identity protection while ensuring efficient information delivery to counselors during non-face-to-face *** proposed systemincorporates a voicemodulation function that instantlymodifies/masks the client’s voice to safeguard their ***,it employs real-time client facial expression recognition using an ensemble of decision trees to mirror the client’s non-verbal expressions through their avatar in the metaverse *** system is adaptable for use on personal computers and smartphones,offering users the flexibility to access metaverse-based psychological counseling across diverse *** performance evaluation of the proposed system confirmed that the voice modulation and real-time facial expression replication consistently achieve an average speed of 48.32 frames per second or higher,even when tested on the least powerful smartphone ***,a total of 550 actual psychological counseling sessions were conducted,and the average satisfaction rating reached 4.46 on a 5-point *** indicates that clients experienced improved identity protection compared to conventional non-face-to-face metaverse counseling ***,the counselor successfully addressed the challenge of conveying non-verbal cues from clients who typically struggled with non-face-to-face psychological *** proposed systemholds significant potential for applications in interactive discussions and educational activities in the metaverse.

关键词： Metaverse counseling system face tracking identity protection

Effect of Eu^(3+),Bi^(3+),and Li^(+) doping on luminescent property of GdNbO_(4)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第1期42卷 66-75,I0003页

作者： s.W.Wi Y.s.lee Department of Physics and Integrative Institute of Basic sciences Soongsil UniversitySeoul06978Republic of Korea

We investigated the emission properties of Eu^(3+)-doped GdNbO_(4)-based oxide phosphors,aiming at improving the Eu^(3+)emission by codoping of Bi^(3+)and Li^(+).Eu^(3+)singly doped,Eu^(3+)and Bi^(3+)doubly doped,and Eu^(3+),Bi^(3+),and Li^(+)triply doped GdNbO_(4)were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu^(3+)in the singly doped samples are significantly improved by the codoping of Bi^(3+),mainly due to the energy transfer from Bi^(3+)to Eu^(3+).The additional codoping of Li^(+)is found to increase the Eu^(3+)emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu^(3+)in GdNbO_(4)does not change significantly with the codoping of Bi^(3+)and Li^(+).Our results indicate that Li^(+)doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO_(4)phosphors.

关键词： Eu^(3+) GdNbO_(4) Codoping of Li^(+) Photoluminescence sensitizer Rare earths

Phase-driven progress in nanophotonic biosensing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(science & Applications) 2024年第5期13卷 798-800页

作者： Isabel Barth Hakho lee Center for systems Biology Massachusetts General HospitalHarvard Medical SchoolBostonMA 02114USA

In the continuous pursuit of enhancing the sensitivity of nanophotonic biosensors by leveraging phase phenomena,a recent development involved the engineering of an atomically thin Ge2sb2Te5 layer on a silver nanofilm ... 详细信息

关键词： silver Ge2sb2Te5 pursuit

Novel fabrication techniques for ultra-thin silicon based flexible electronics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第4期6卷 116-149页

作者： Ju Young lee Jeong Eun Ju Chanwoo lee sang Min Won Ki Jun Yu school of electrical and electronic Engineering Yonsei University50 Yonsei-roSeodaemunguSeoul 03722Republic of Korea Department of electrical and Computer Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea YU-Korea Institute of science and Technology(KIsT)Institute Yonsei University50Yonsei-roSeodaemun-guSeoul 03722Republic of Korea

Flexible electronics offer a multitude of advantages,such as flexibility,lightweight property,portability,and high *** unique properties allow for seamless applications to curved and soft surfaces,leading to extensive utilization across a wide range of fields in consumer *** applications,for example,span integrated circuits,solar cells,batteries,wearable devices,bio-implants,soft robotics,and biomimetic ***,flexible electronic devices have been developed using a variety of materials such as organic,carbon-based,and inorganic semiconducting ***(si)owing to its mature fabrication process,excellent electrical,optical,thermal properties,and cost efficiency,remains a compelling material choice for flexible ***,the research on ultra-thin si in the context of flexible electronics is studied rigorously *** thinning of si is crucially important for flexible electronics as it reduces its bending stiffness and the resultant bending strain,thereby enhancing flexibility while preserving its exceptional *** review provides a comprehensive overview of the recent efforts in the fabrication techniques for forming ultra-thin si using top-down and bottom-up approaches and explores their utilization in flexible electronics and their applications.

关键词： flexible electronics silicon fabrication technique top-down approach bottom-up approach

Exploring the relationship between rarity and price of profile picture NFT:A formal concept analysis on the BAYC NFT collection

在线全文

学校读者我要写书评

暂无评论

Blockchain(Research and Applications) 2024年第2期5卷 140-150页

作者： Heejung lee Geun-Cheol lee Hoon-Young Koo school of Interdisciplinary Industrial studies Hanyang University222 Wangsimni-roSeongdong-guSeoul04763Republic of Korea College of Business Administration Konkuk University120 Neungdong-roGwangjin-guSeoul05029Republic of Korea school of Business Chungnam National University99 Daehak-roYuseong-guDaejeon34134Republic of Korea

Non-fungible token(NFT)is a digital asset whose ownership can be validated and controlled via blockchain *** NFT market is a rapidly growing field,and the rarity of NFT is an essential factor that affects its price,as scarcity leads to higher *** study focuses on the BAYC NFT collection,which is a successful and representative collection of profile picture NFT,and analyzes how rarity affects NFT *** paper investigates the relationship between the rarity and price of the BAYC NFT collection using formal concept analysis(FCA)*** results show that rarity is a major factor influencing the price of NFT and the effect is more apparent in the medium rarity *** rarity is very high or very low,other factors become significant determinants,such as the uniqueness and appeal of NFT,and even the naturalness of NFT *** research highlights the importance of considering rarity when assessing NFT and underscores the need for a comprehensive evaluation of NFT *** study also provides valuable insights into the NFT market and can be useful for NFT investors,creators,and ***,the usefulness of FCA as a tool for quantifying NFT rarity and evaluating NFT price was demonstrated.

关键词： NFT valuation Formal concept analysis Rarity

Classification and technical target of water electrolysis for hydrogen production

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第8期95卷 554-576,I0012页

作者： Kahyun Ham sooan Bae Jaeyoung lee Ertl Center for electrochemistry and Catalysis Gwangju Institute of Science and Technology(GIST)123 Cheomdangwagi-RoBuk-guGwangju 61005South Korea Department of Heterogeneous Reactions Max Planck Institute for Chemical Energy ConversionStiftstr.34-36Mülheim an der RuhrGermany school of Earth sciences and Environmental Engineering GIST123 CheomdangwagiroBuk-guGwangju 61005South Korea International Future Research Center of Chemical Energy storage and Conversion Processes GIST123 CheomdangwagiroBuk-guGwangju 61005South Korea esus Co. Ltd.#408S6 BuildingSchool of Environment and Energy EngineeringGIST123 CheomdangwagiroBuk-guGwangju 61005South Korea

Continuous efforts are underway to reduce carbon emissions worldwide in response to global climate *** electrolysis technology,in conjunction with renewable energy,is considered the most feasible hydrogen production technology based on the viable possibility of large-scale hydrogen production and the zero-carbon-emission nature of the ***,for hydrogen produced via water electrolysis systems to be utilized in various fields in practice,the unit cost of hydrogen production must be reduced to$1/kg H_(2).To achieve this unit cost,technical targets for water electrolysis have been suggested regarding components in the *** this paper,the types of water electrolysis systems and the limitations of water electrolysis system components are *** suggest guideline with recent trend for achieving this technical target and insights for the potential utilization of water electrolysis technology.

关键词： Water electrolysis Hydrogen production Technical target electrochemistry