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Dimensionality-driven metal to Mott insulator transition in two-dimensional 1T-TaSe2

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National Science Review 2024年第3期11卷 108-118页

作者： Ning Tian Zhe Huang Bo Gyu Jang Shuaifei Guo Ya-Jun Yan Jingjing Gao Yijun Yu Jinwoong Hwang Cenyao Tang Meixiao Wang Xuan Luo Yu Ping Sun Zhongkai Liu Dong-Lai Feng Xianhui Chen Sung-Kwan Mo Minjae Kim young-Woo son Dawei Shen Wei Ruan Yuanbo Zhang State Key Laboratory of Surface Physics New Cornerstone Science Laboratory and Department of PhysicsFudan University Shanghai Qi Zhi Institute Shanghai Research Center for Quantum Sciences Institute for Nanoelectronic Devices and Quantum Computing Fudan University Zhangjiang Fudan International Innovation Center Fudan University State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology(SIMIT)Chinese Academy of Sciences School of Physical Science and Technology ShanghaiTech University Korea Institute for Advanced Study School of Emerging Technology and Department of Physics University of Science and Technology of China Advanced Light Source Lawrence Berkeley National Laboratory ShanghaiTech Laboratory for Topological Physics Key Laboratory of Materials Physics Institute of Solid State Physics Hefei Institutes of Physical ScienceChinese Academy of Sciences High Magnetic Field Laboratory Hefei Institutes of Physical Science Chinese Academy of Sciences Collaborative Innovation Centre of Advanced Microstructures Nanjing University Department of Physics University of Science and Technology of China and Key Laboratory of Strongly Coupled Quantum Matter Physics Chinese Academy of Sciences National Synchrotron Radiation Laboratory University of Science and Technology of China

Two-dimensional materials represent a major frontier for research into exotic many-body quantum phenomena. In the extreme two-dimensional limit, electron-electron interaction often dominates over other electronic energy scales, leading to strongly correlated effects such as quantum spin liquid and unconventional *** dominance is conventionally attributed to the lack of electron screening in the third dimension. Here, we discover an intriguing metal to Mott insulator transition in 1T-TaSe2that defies conventional wisdom. Specifically, we find that dimensionality crossover, instead of reduced screening, drives the transition in atomically thin 1T-TaSe2. A dispersive band crossing the Fermi level is found to be responsible for the bulk metallicity in the material. Reducing the dimensionality,however, effectively quenches the kinetic energy of these initially itinerant electrons, and drives the material into a Mott insulating *** dimensionality-driven metal to Mott insulator transition resolves the long-standing dichotomy between metallic bulk and insulating surface of 1T-TaSe2. Our work further reveals a new pathway for modulating two-dimensional materials that enables exploring strongly correlated systems across uncharted parameter space.

关键词： two-dimensional materials 1T-TaSe2 dimensionality crossover metal to Mott insulator transition

Synapsing with NG2 cells(polydendrocytes),unappreciated barrier to axon regeneration?

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Neural Regeneration Research 2015年第3期10卷 346-348页

作者： young-Jin son Shriners Hospitals Pediatric Research Center and Department of Anatomy and Cell Biology Temple University School of Medicine

Have you heard of NG2 cells or NG2 glia or polydendro- cytes~. These are new names for the precursor cells that used to be referred to as oligodendrocyte precursor cells （OPCs）, which become the oligodendrocytes that myelinate central nervous system （CNS） axons. Evidence suggests, however, that they have other functions, besides differentiating into oligodendrocytes. Most notably, the OPCs/NG2 cells are uni- formly distributed in grey matter as well as in white matter, which matches poorly with the distribution of myelinating oligodendrocytes. Furthermore, not every NG2 cell is fated to become an oligodendrocyte. Hence the term OPC can be fairly applied only when discussing the role of these cells in the oligodendrocyte lineage.

关键词： NG cell Synapsing with NG2 cells polydendrocytes unappreciated barrier to axon regeneration

The Immersed Interface Hybridized Difference Method for Parabolic Interface Problems

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Numerical Mathematics(Theory,Methods and Applications) 2022年第2期15卷 336-359页

作者： youngmok Jeon son-young Yi Department of Mathematics Ajou UniversitySuwon 16499Republic of Korea Department of Mathematical Sciences The University of Texas at El PasoEl PasoTX 79968USA

We propose several immersed interface hybridized difference methods(IHDMs),combined with the Crank-Nicolson time-stepping scheme,for parabolic interface *** IHDM is the same as the hybrid difference method away from the interface cells,but the finite difference operators on the interface cells are modified tomaintain the same accuracy throughout the entire *** themodification process,we consider virtual extensions of two sub-solutions in the interface cells in such a way that they satisfy certain jump equations between *** propose several different sets of jump equations and their resulting discrete methods for one-and two-dimensional *** numerical results are presented to demonstrate the accuracy and robustness of the proposed methods.

关键词： Parabolic interface problem hybrid difference method immersed interface

A facile synthesis of hierarchical Sn3O4 nanostructures in an acidic aqueous solution and their strong visible- light-driven photocatalytic activity

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Nano Research 2015年第11期8卷 3553-3561页

作者： Hui song Su-young son Seul Ki Kim Gun young Jung School of Materials Science and Engineering Gwangju Institute of Science and Technology (GIST) Gwangju 500-712 Republic of Korea Carbon Convergence Materials Research Center Institute of Advanced Composite Materials Korea Institute of Science and Technology (KIST) Jeollabuk-do 565-905 Republic of Korea

Hierarchical tin（Ⅲ） oxide, Sn3O4, nanospheres were synthesized via hydrothermal reaction under strongly acidic ambient conditions. The morphology of Sn3O4 varied with decreasing pH. The prickly SnaO4 nanospheres changed into SnaO4 nanospheres covered with single-crystalline nanoplates having a high BET surface area of ca. 55.05 m^2·g^-1 and a band gap of ca. 2.25 eV. Small amounts （0.05 g） of the hierarchical Sn3O4 nanostructures completely decomposed a 30% methyl orange （MO） solution in 100 mL deionized water within 15 min under one sun condition （UV ＋ visible light）. The Sn3O4 photocatalyst exhibited a fast decomposition rate of 1.73 ×10^-1 min^-1, which is a 90.86% enhancement relative to that of the commercially available P25 photocatalyst. The high photocatalytic activity of the hierarchical Sn3O4 nanostructures is attributed to its ability to absorb visible light and its high surface-to-volume ratio.

关键词： Sn3O4 hierarchical structure hydrothermal morphology engineering photocatalyst

Fast ethylamine gas sensing based on intermolecular charge-transfer complexation

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Chinese Chemical Letters 2012年第4期23卷 484-487页

作者： Eun Mi Lee Seon young Gwon young A son Sung Hoon Kim BK21 FTIT Department of Advanced Organic Materials and Textile System EngineeringChungnam National UniversityDaejeon 305-764Republic of Korea Department of Textile System Engineering Kyungpook National UniversityDaegu 702-701 Republic of Korea School of Chemistry Science & Technology Zhanjiang Normal UniversityZhanjiang 524048China

We have investigated the fast ethylamine gas sensing of 2-chloro-3,5-dinitrobenzotrifluoride（CDBF） loaded poly（acrylonitrile） nanofiber based on an intermolecular charge-transfer *** response and recovery were ach... 详细信息

关键词： Ethylamine gas Fast gas sensing 2-Chloro-3 5-dinitrobenzotrifluoride(CDBF) Electrospinning PAN nanofiber Intermolecular charge-transfer(CT) complexation

Uniform assembly of gold nanoparticles on S-doped g-C3N4 nanocomposite for effective conversion of 4-nitrophenol by catalytic reduction

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Journal of Materials Science & Technology 2020年第5期40卷 176-184页

作者： Vellaichamy Balakumar Hyungjoo Kim Ji Won Ryu Ramalingam Manivannan young-a son Department of Advanced Organic Materials Engineering Chungnam National University220 Gung-dongYuseong-guDaejeon305-764South Korea

In this work,a simple synthesis of sulfur doped graphitic carbon nitride(S-g-C3N4)act as a support cum stabilizers for gold nanoparticles(Au)and its was characterized by UV–vis and XRD to measure the absorbance and crystallinity,*** functional group and morphology of the samples were identified using FT-IR and ***,the Au@S-g-C3N4 nanocatalyst exhibits good catalytic performance and stability in the reduction of hazardous 4-nitrophenol(NP)compared to S-g-C3N4 using Na ***,the Au@S-g-C3N4 nanocomposite holds a good catalytic efficiency(near 100%)achieved by within 5 *** highest catalytic reduction of NP is due to the synergistic effect of Au nanoparticles decorated on *** fast electron transfer reduction mechanism was elucidated and *** reusability and stability of the developed nanocomposites were also observed in consecutive reduction *** filtering and catalyzing device was used for the direct conversion of NP polluted *** method can open a new avenue for the metal nanoparticles based carbon materials heterogeneous catalyst and its reduction of toxic contaminants.

关键词： Gold nanoparticles S-doped g-C3N4 Catalytic reduction 4-nitrophenol

Authentication masking code against DoS of T-MAC protocol

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Journal of Central South University 2013年第7期20卷 1889-1895页

作者： son young-ho HONG Jin-keun BAE Keun-sung Attached Institute of ETRI Division of Information & Communication Baekseok University School of Electrical Engineering & Computer Science Kyungpook National University

Security vulnerability of denial of service (DoS) in time out-medium access control (T-MAC) protocol was discussed and analysis of power consumption at each stage of T-MAC protocol was carried out. For power efficient authentication scheme which can provide reliability, efficiency, and security for a general T-MAC communication, a novel synchronization and authentication scheme using authentication masking code was proposed. Authentication data were repeated and masked by PN sequence. The simulation results show that the proposed approach can provide synchronization and authentication simultaneously for nodes in wireless sensor network (WSN). 63 bits AMC code gives above 99.97% synchronization detection and 93.98% authentication data detection probability in BER 0.031 7.

关键词： time out-medium access control (T-MAC) security vulnerability authentication synchronization authenticationmasking code

Effect of Laser Parameters on Sintered Powder Morphology

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Journal of Materials Science & Technology 2010年第4期26卷 375-378页

作者： Byeong-Don Joo Jeong-Hwan Jang Jae-Ho Lee young-Myung son young-Hoon Moon Engineering Research Center for Net Shape and Die Manufacturing School of Mechanical EngineeringPusan National University

Selective laser sintering is a kind of rapid prototyping process whereby a three-dimensional part is built layerwise by laser scanning a powder. This process is highly inffuenced by powder and laser parameters such as laser power, scan rate, spot size and layer thickness. Therefore a study on fabricating a line with Fe-Ni-Cr powder on AISI H13 tool steel has been performed by selective laser sintering. In this study, fabrication was performed by experimental facilities consisting of a 200W fiber laser which can be focused to 0.08 mm and atmospheric chamber which can control atmospheric pressure with argon. The line was fabricated with various laser power, scan rate and layer thickness. Line width and surface quality were investigated. With power increase or layer thickness decrease, line width was decreased and line surface quality was improved with scan rate optimization.

关键词： Selective laser sintering Direct fabrication Fiber laser

Laser surface hardening of AISI H13 tool steel

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中国有色金属学会会刊：英文版 2009年第4期19卷 917-920页

作者： Jae-Ho LEE Jeong-Hwan JANG Byeong-Don JOO young-Myung son young-Hoon MOON School of Mechanical Engineering Pusan National University

An attempt was made to improve the surface hardness and wear properties of AISI H13 tool steel through solid solution hardening and refinement of microstructures using a 200 W fiber laser as a heat generating *** hardness of laser melted zone was *** order to identify the effect of heat input on the laser melting zone,scanning conditions were *** results show that,the hardness of as-received AISI H13 tool steel is approximately Hv 240,and the hardness after laser surface heat treatment is around Hv *** hardening depth and width are increased with the increase in the heat input *** of experimental results will be considered in tooling industry.

关键词：激光表面硬化工具钢 H13 激光表面热处理表面硬度信息社会光纤激光器固溶强化