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Cool white light and tunable multicolor emission from Tb^(3+)/Dy^(3+)co-activated glasses under different excitations for WLEDs

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Journal of Rare Earths 2024年第1期42卷 46-56,I0002页

作者： L.Vijayalakshmi K.Naveen Kumar jong Dae baek Department of Automotive Engineering Yeungnam UniversityGyeongsanGyeongbuk38541Republic of Korea Department of Mechanical Engineering Yeungnam UniversityGyeongsan38541Republic of Korea

A set of co-doped(Tb^(3+)/Dy^(3+))lithium zinc borate(LZB)glasses were developed by melt *** structural evaluation was performed for synthesized glassy *** Dy^(3+)and Tb^(3+)individually doped glasses exhibit intense yellow and green luminescence bands at 575 nm(^(4)F_(9/2)→^(6)H_(13/2))and543 nm(^(5)D_(4)→^(7)F_(5)),*** sensitization effect of Dy^(3+)on Tb^(3+)was analyzed by increasing the Tb^(3+)content with respect to the optimum Dy^(3+)content(0.5 mol%)in Dy^(3+)/Tb^(3+).The spectral overlay of Dy^(3+)luminescence and Tb^(3+)absorption profiles,Dy^(3+)/Tb^(3+)PL spectra under different excitations 352,362,376,and 385 nm,shortening decay lifetimes of Dy^(3+)in Dy^(3+)/Tb^(3+)co-activated glasses,energy transfer(ET)parameters,chromaticity coordinates and their corresponding correlated temperatures all help to explain ET from Dy^(3+)to Tb^(3+).At 385 nm of Dy^(3+)excitation,the optimized co-activated(0.5Dy^(3+)+1.0Tb^(3+)):LZB glass displays cool white light *** non-radiative ET from Dy^(3+)to Tb^(3+)is dominated by electric dipole-dipole interaction and its ET efficiency was calculated to be 63%.At the same time,reverse ET from Tb^(3+)to Dy^(3+)was also *** shift in color coordinates from dominant yellow to greenish-yellow,green and white light emission suggests that Dy^(3+)/Tb^(3+)coactivated LZB glasses can be a potential candidate for UV converted multicolor and white light emitting devices.

关键词： Rare earths Photoluminescence Energy transfer Spectral overlap Decay lifetime Multicolor emitting LEDs

Active Site Engineering in Transition Metal Based Electrocatalysts for Green Energy Applications

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Accounts of Materials Research 2021年第3期2卷 147-158页

作者： Feng Li Gao-Feng Han jong-beom baek School of Energy and Chemical Engineering/Center for Dimension-Controllable Organic Frameworks Ulsan National Institute of Science and Technology(UNIST)Ulsan 44919South Korea

CONSPECTUS:Hydrogen is widely considered an ideal green energy carrier and a leading candidate to replace nonrenewable fossil fuels and address serious global energy and environmental pollution *** worldwide are engaged in developing various technologies related to hydrogen energy exploitation and conversion,such as photocatalytic/electrocatalytic water splitting,fuel cells,and so *** water splitting using electric energy can produce clean and pure hydrogen from water on a large scale,which can be further directly converted into electric energy by fuel *** environmentally friendly system relies on a series of important reactions,especially the hydrogen evolution reaction(HER)and oxygen reduction reaction(ORR),which both require high efficiency and durable *** the tremendous efforts of the scientific community,electrocatalysts with satisfactory performance are still *** the heart of electrocatalysts,active sites are key to catalytic *** site engineering,by tuning the nature of the active sites in the electrocatalysts,offers an important opportunity to improve the performance of ***,the strategies for active site engineering involve(1)tailoring the environment around the active sites and(2)engineering the structure of the active *** approaches can be used to optimize the electronic properties of the active sites,balance the binding energies between the active sites and the reactants/intermediates/products,and thus accelerate the overall reaction *** this Account,we summarize the recent progress made in our laboratory on active site engineering in transition metal based electrocatalysts for green energy *** start with metal nanoparticle electrocatalysts,engineering Ru nanoparticles on different supports,to achieve more efficient electrocatalytic HER ***,after we theoretically predicted that the hydrogen adsorption/desorption o

关键词： Transition replace arrangement

Influence of contact curvature on frictional energy dissipation under varying tangential loads

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Friction 2024年第2期12卷 363-374页

作者： Sumin baek Seunghun baek School of Mechanical Engineering Pusan National UniversityPusan 46241Republic of Korea

This study investigates the effect of contact surface curvatures on the friction response under varying tangential loadings using a finite element(FE)*** results showed that the geometry of the surface influences the contact force at the interface and reduces the friction effect through an unsteady distribution of the contact *** relationship between the friction effect,excitation,and contact surface shape was also examined,revealing a linear inverse relationship between the friction and *** findings provide a comprehensive understanding of the frictional interactions between elastic bodies and highlight the role of curvature as a design parameter for regulating the friction effect.

关键词： frictional contact curvelinear contact frictional energy dissipation contact curvature

Understanding of the capacity Contribution of carbon in phosphorus-carbon composites for high-performance anodes in lithium ion batteries

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Nano Research 2017年第4期10卷 1268-1281页

作者： Jiantie Xu In-Yup Jeon Jianmin Ma Yuhai Dou Seok-Jin Kim Jeong-Min Seo Huakun Liu Shixue Dou jong-beom baek Liming Dai Institute for Superconducting and Electronic Materials University of Wollongong Wollongong NSW 2522 Austrafia School of Energy and Chemical Engineering/Low-Dimensional Carbon Materials Center Ulsan National Institute of Science and Technology (UNIST) UNIST-gi150 Ulsan 689-897 Republic of Korea Department of Macromolecular Science and Engineering Case Western Reserve University Cleveland OH 44106 USA

Phosphorus has recently received extensive attention as a promising anode for lithium ion batteries （LIBs） due to its high theoretical capacity of 2,596 mAh·g^-1. To develop high-performance phosphorus anodes for LIBs, carbon materials have been hybridized with phosphorus （P-C） to improve dispersion and con- ductivity. However, the specific capacity, rate capability, and cycling stability of P-C anodes are still less than satisfactory for practical applications. Furthermore, the exact effects of the carbon support on the electrochemical performance of the P-C anodes are not fully understood. Herein, a series of xP-yC anode materials for LIBs were prepared by a simple and efficient ball-milling method. 6P-4C and 3P-7C were found to be optimum mass ratios of x/y, and delivered initial discharge capacities of 1,803.5 and 1,585.3-mAh·g^-1, respectively, at 0.1 C in the voltage range 0.02-2 V, with an initial capacity retention of 68.3% over 200 cycles （more than 4 months cycling life） and 40.8% over 450 cycles. The excellent electrochemical performance of the 6P-4C and 3P-7C samples was attributed to a synergistic effect from both the adsorbed P and carbon.

关键词： phosphorus carbon synergistic effect anode lithium ion batteries

A Novel Framework to Construct S-Box Quantum Circuits Using System Modeling: Application to 4-Bit S-Boxes

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Computer Modeling in Engineering & Sciences 2024年第10期141卷 545-561页

作者： Yongjin Jeon Seungjun baek jongsung Kim Department of Financial Information Security Kookmin UniversitySeoul02707Republic of Korea

Quantum computers accelerate many algorithms based on the superposition principle of quantum *** Grover algorithm provides significant performance to malicious users attacking symmetric key *** the performance of attacks using quantum computers depends on the efficiency of the quantum circuit of the encryption algorithms,research research on the implementation of quantum circuits is *** paper presents a new framework to construct quantum circuits of substitution boxes(S-boxes)using system *** model the quantum circuits of S-boxes using two layers:Toffoli and linear *** generate vector spaces based on the values of qubits used in the linear layers and apply them to find quantum *** framework finds the circuit bymatching elements of vector spaces generated fromthe input and output of a given S-box,using the forward search or themeet-in-the-middle *** developed a tool to apply this framework to 4-bit *** the 4-bit S-box quantum circuit construction tool LIGHTER-R only finds circuits that can be implemented with four qubits,the proposed tool achieves the circuits with five *** proposed tool can find quantum circuits of 4-bit odd permutations based on the controlled NOT,NOT,and Toffoli gates,whereas LIGHTER-R is unable to perform this task in the same *** expect this technique to become a critical step toward optimizing S-box quantum circuits.

关键词： System modeling quantum circuit S-box circuit quantum computer

Postmortem ^(7)Li NMR analysis for assessing the reversibility of lithium metal electrodes in lithium metal batteries

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Journal of Energy Chemistry 2024年第7期94卷 430-440页

作者： Jaewon baek Sunha Kim Hee-Tak Kim Oc Hee Han Department of Chemical&Biomolecular Engineering KAISTDaejeon 34141Republic of Korea Metropolitan Seoul Center Korea Basic Science InstituteSeoul 03759Republic of Korea Graduate School of Analytical Science&Technology Chungnam National UniversityDaejeon 34134Republic of Korea

Despite the proficiency of lithium(Li)-7 NMR spectroscopy in delineating the physical and chemical states of Li metal electrodes,challenges in specimen preparation and interpretation impede its *** this study,we conducted a comprehensive postmortem analysis utilizing ^(7)Li NMR,employing a stan-dard magic angle spinning probe to examine protective-layer coated Li metal electrodes and LiAg alloy electrodes against bare Li metal electrodes within Li metal batteries(LMBs).Our investigation explores the effects of sample burrs,alignment with the magnetic field,the existence of liquid electrolytes,and precycling on the ^(7)Li NMR *** contrasting NMR spectra before and after cycling,we identi-fied alterations in Li^(0) and Li^(+) signals attributable to the degradation of the Li metal *** NMR analyses decisively demonstrate the efficacy of the protective layer in mitigating dendrite and solid elec-trolyte interphase ***,we noted that Li*ions near the Li metal surface exhibit magnetic susceptibility anisotropy,revealing a novel approach to studying diamagnetic species on Li metal elec-trodes in *** study provides valuable insights and practical guidelines for characterizing distinct lithium states within LMBs.

关键词： NMR spectroscopy Lithium-7 Lithium metal battery Electrolyte Electrode-protective layer Solid electrolyte interface Magnetic susceptibility anisotropy Lithium-metal NMR signal Diamagnetic^(7)Li NMR signal

Dual-logic-in-memory implementation with orthogonal polarization of van der Waals ferroelectric heterostructure

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InfoMat 2024年第2期6卷 107-117页

作者： Jingjie Niu Sumin Jeon Donggyu Kim Sungpyo baek Hyun Ho Yoo Jie Li Ji-Sang Park Yoonmyung Lee Sungjoo Lee SKKU Advanced Institute of Nanotechnology(SAINT) Sungkyunkwan UniversitySuwonRepublic of Korea Department of Nano Science and Technology Sungkyunkwan UniversitySuwonRepublic of Korea Department of Electrical and Computer Engineering Sungkyunkwan UniversitySuwonRepublic of Korea IMEC HeverleeBelgium Department of Nano Engineering Sungkyunkwan UniversitySuwonRepublic of Korea

The rapid advancement of AI-enabled applications has resulted in an increasing need for energy-efficient computing ***-in-memory is a promising approach for processing the data stored in memory,wherein fast and efficient computations are possible owing to the parallel execution of reconfigurable logic *** this study,a dual-logic-in-memory device,which can simultaneously perform two logic operations in four states,is demonstrated using van der Waals ferroelectric field-effect transistors(vdW FeFETs).The proposed dual-logic-in-memory device,which also acts as a twobit storage device,is a single bidirectional polarization-integrated ferroelectric field-effect transistor(BPI-FeFET).It is fabricated by integrating an in-plane vdW ferroelectric semiconductor SnS and an out-of-plane vdW ferroelectric gate dielectric material—CuInP_(2)S_(6).Four reliable resistance states with excellent endurance and retention characteristics were *** two-bit storage mechanism in a BPI-FeFET was analyzed from two perspectives:carrier density and carrier injection controls,which originated from the out-of-plane polarization of the gate dielectric and in-plane polarization of the semiconductor,*** conventional multilevel FeFETs,the proposed BPIFeFET does not require additional pre-examination or erasing steps to switch from/to an intermediate polarization,enabling direct switching between the four memory *** utilize the fabricated BPI-FeFET as a dual-logic-inmemory device,two logical operations were selected(XOR and AND),and their parallel execution was *** types of logic operations could be implemented by selecting different initial states,demonstrating various types of functions required for numerous neural network *** flexibility and efficiency of the proposed dual-logic-in-memory device appear promising in the realization of next-generation low-power computing systems.

关键词： ferroelectric field-effect transistor in-plane ferroelectricity logic-in-memory out-of-plane ferroelectricity

Metabolic relationships between marine red algae and algae‑associated bacteria

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Marine Life Science & Technology 2024年第2期6卷 298-314页

作者： Kyung Hyun Kim Jeong Min Kim Ju Hye baek Sang Eun Jeong Hocheol Kim Hwan Su Yoon Che Ok Jeon Department of Biological Sciences and Biotechnology Hannam UniversityDaejon 34054Republic of Korea Department of Life Science Chung-Ang UniversitySeoul 06974Republic of Korea Department of Biological Sciences Sungkyunkwan UniversitySuwon 16419Republic of Korea

Mutualistic interactions between marine phototrophs and associated bacteria are an important strategy for their success-ful survival in the ocean,but little is known about their metabolic ***,bacterial communities in the algal sphere(AS)and bulk solution(BS)of nine marine red algal cultures were analyzed,and Roseibium and Phycisphaera were identified significantly more abundantly in AS than in *** metabolic features of Roseibium RMAR6-6(isolated and genome-sequenced),Phycisphaera MAG 12(obtained by metagenomic sequencing),and a marine red alga,Porphyridium purpureum CCMP1328(from GenBank),were analyzed ***6-6 has the genetic capability to fix nitrogen and produce B vitamins(B1,B2,B5,B6,B9,and B12),bacterioferritin,dimethylsulfoniopropionate(DMSP),and phenylacetate that may enhance algal growth,whereas MAG 12 may have a limited metabolic capability,not producing vitamins B9 and B12,DMSP,phenylacetate,and siderophores,but with the ability to produce bacitracin,possibly modulating algal *** CCMP1328 lacks the genetic capability to fix nitrogen and produce vitamin B12,DMSP,phenylacetate,and *** was shown that the nitrogen-fixing ability of RMAR6-6 promoted the growth of ***-pureum,and DMSP reduced the oxidative stress of *** metabolic interactions between strain RMAR6-6 and *** CCMP1328 were also investigated by the transcriptomic analyses of their monoculture and *** together,potential metabolic relationships between Roseibium and *** were *** study provides a bet-ter understanding of the metabolic relationships between marine algae and algae-associated bacteria for successful growth.

关键词： Metabolic relationship Marine red algae Symbiotic bacteria Roseibium Phycisphaera Porphyridium

Body-Shaping Membrane to Regenerate Breast Fat by Elastic Structural Holding

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Research 2024年第1期2023卷 165-180页

作者： Hye-Seon Kim Jeongeun Park Hyun-Su Ha Sewoom baek Chan Hee Lee Kyubae Lee Suji Park Jueun Kim Se Won Yi Hak-Joon Sung Department of Medical Engineering Graduate School of Medical ScienceBrain Korea 21 ProjectYonsei University College of MedicineSeoul 03722Republic of Korea TMD LAB Co.Ltd. 6th Floor31Gwangnaru-ro 8-gilSeongdong-guSeoul 04799Republic of Korea

Tissue regeneration requires structural holding and movement support using tissue-type-specific aids such as bone casts,skin bandages,and joint ***,an unmet need exists in aiding breast fat regeneration as the breast moves following continuous body motion by exposing the breast fat to dynamic ***,the concept of elastic structural holding is applied to develop a shape-fitting moldable membrane for breast fat regeneration(“adipoconductive”)after surgical defects are *** membrane has the following key characteristics:(a)It contains a panel of honeycomb structures,thereby efficiently handling motion stress through the entire membrane;(b)a strut is added into each honeycomb in a direction perpendicular to gravity,thereby suppressing the deformation and stress concentration upon lying and standing;and(c)thermo-responsive moldable elastomers are used to support structural holding by suppressing large deviations of movement that occur *** elastomer became moldable upon a temperature shift above T_(m).The structure can then be fixed as the temperature *** a result,the membrane promotes adipogenesis by activating mechanotransduction in a fat miniature model with pre-adipocyte spheroids under continuous shaking in vitro and in a subcutaneous implant placed on the motion-prone back areas of rodents in vivo.

关键词： thereby shaking Elastic