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Journal of Materials Science & Technology 2021年第2期61卷 93-99页

作者： Hong Sun Nan Deng Jianqiang Li gang he Jiangtao Li National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology CAS Key Laboratory of Green Process and Engineering.Institute of Process EngineeringChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijing100190China

Graphite flake/Cu composite has attracted tremendous attention as a promising heat sinks materials owing to its easy machinability and superior thermal properties. However, its preparation process still faces several technological limitations including complex, time-consuming and costly synthetic approaches. In this work, a facile and scalable intermittently electroplated method is applied to prepare Cu-coated graphite flake composite powders, which are subsequently sintered into dense composite bulks. The results show that the graphite flake is successfully coated with a uniform and compact Cu shell,which effectively inhibits the segregation accumulation of graphite flakes and contributes to homogeneous distribution of graphite in the sintered graphite flake/Cu composites. The as-sintered composites exhibit an excellent thermal conductivity of 710 W·m-1·K-1and an outstanding bending strength of 93 MPa. Such performance, together with the simple, efficient powder-preparation process, suggests that the present strategy may open up opportunities for the development of thermal management materials.

关键词： Graphite flake Electroplating Powder processing Thermal properties

Microstructure and properties of porous Si_(3)N_(4)ceramics by gelcasting-self-propagating high-temperature synthesis(SHS)

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Journal of Advanced Ceramics 2022年第1期11卷 172-183页

作者： Shile CheN Liang WANG gang he Jiangtao LI Chang-An WANG State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China CAS Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China

Porous silicon nitride ceramics have attracted a considerable attention due to their excellent overall performance,but poor porosity homogeneity and structural shrinkage induced by prolonged high temperature sintering limit its further ***,as a three-in-one solution for the above issues,for the first time we develop a novel approach that integrates the merits of gelcasting-SHS(self-propagating high-temperature synthesis)to prepare porous Si_(3)N_(4)ceramics to simultaneously achieve high porosity,high strength,high toughness,and low thermal conductivity across a wide temperature *** regulating the solid content,porous Si_(3)N_(4)ceramics with homogeneous pore structure are obtained,where the pore size falls inbetween 1.61 and 4.41 pm,and the elongated grains are interlaced and interlocked to form micron-sized coherent interconnected *** the same time,porous Si_(3)N_(4)ceramics with porosity of 67.83%to 78.03%are obtained,where the compressive strength reaches 11.79 to 47.75 MPa and fracture toughness reaches 1.20 to 6.71 MPa-m1/2.

关键词： porous Si_(3)N_(4)ceramics gelcasting self-propagating high-temperature synthesis(SHS) porosity

Physical Mechanism and Performance Factors of Metal Oxide Based Resistive Switching Memory:A Review

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Journal of Materials Science & Technology 2016年第1期32卷 1-11页

作者： Cong Ye Jiaji Wu gang he Jieqiong Zhang Tengfei Deng Pin he Hao Wang Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials Hubei Key Laboratory of Ferroelectric and Dielectric Materials and DevicesFaculty of Physics and Electronic ScienceHubei University School of Physics and Materials Science Radiation Detection Materials & Device LabAnhui University Department of Electrical Engineering City University of Hong KongHong Kong Special Administrative Region

This review summarizes the mechanism and performance of metal oxide based resistive switching memory. The origin of resistive switching （RS） behavior can be roughly classified into the conducting filament type and the interface type. here, we adopt the filament type to study the metal oxide based resistive switch- ing memory, which considers the migration of metallic cations and oxygen vacancies, as well as discuss two main mechanisms including the electrochemical metallization effect （ECM） and valence change memory effect （VCM）. At the light of the influence of the electrode materials and switching layers on the RS char- acteristics, an overview has also been given on the performance parameters including the uniformity, endurance, the retention, and the multi-layer storage. Especially, we mentioned ITO （indium tin oxide） electrode and discussed the novel RS characteristics related with ITO. Finally, the challenges resistive random access memory （RRAM） device is facing, as well as the future development trend, are expressed.

关键词： RRAM (resistive random access memory) Transition metal oxide Conductive filament Resistive switching

Effect of Structure Parameters on Power and Magnetic Field in Electromagnetic Soft-Contact Continuous Casting System

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Journal of Iron and Steel Research International 2008年第1期15卷 19-24页

作者： DENG An-yuan WANG En-gang he Ji-cheng Key Laboratory of National Education Ministry for Electromagnetic Processing of Materials Northeastern UniversityShenyang 110004 Liaoning China

To design a power source system and mold for electromagnetic soft-contact continuous casting process and to theoretically estimate the heat losses from the charges and the system power, the effect of structure parameters on system power and magnetic flux density distribution was calculated using finite element method. The results show that as for electromagnetic soft-contact continuous casting system with partial-segment type mold, the power consumption is much more than that with a full-segment type mold; about 62% of electric power is dissipated in the mold, and the effective acting range of magnetic field is relatively narrow. Optimizing mold structure is a crucial measure of remarkably reducing mold power consumption and saving electric energy. Increasing slit number, width, and length can remarkably increase the magnetic flux density in the mold and can reduce the electric energy consumption. Among structure parameters, slit number and slit width are relatively more effective to reduce energy consumption. For a round billet electromagnetic continuous casting system with diameter of 178 ram, the reasonable slit number, width, and length are about 24--32, 0. 5--1.0 mm, and 160 mm, respectively.

关键词： continuous casting soft-contact mold electromagnetic field electric power structure parameter

Meniscus Behavior in Electromagnetic Soft-Contact Continuous Casting Round Billet Mold

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Journal of Iron and Steel Research International 2006年第4期13卷 13-16页

作者： DENG An-yuan WANG En-gang he Ji-cheng Key Laboratory of National Education Ministry for Electromagnetic Processing of Materials NortheasternUniversity Shenyang 110004 Liaoning China

Using molten Pb-Sn-Bi alloy, the meniscus shape under high frequency magnetic field of φ100 mm round billet caster was investigated. The effect of some parameters on meniscus shape was studied. The results show that for a mold with 12 segments, the meniscus shape is relatively stable. With increasing power input, the menis- cus height increases with intensification of fluctuation. For the given caster, the reasonable power input is about 70 kW. The coil should be near to the top of mold and/or the initial meniscus should be near to the center of the coil. The lower the frequency, the higher is the meniscus height. With increasing frequency, the free surface is more flattened and meniscus becomes more stable. In practice, the power input should be increased simultaneously with frequency. The optimal frequency is about 20 kHz.

关键词： continuous casting soft-contact mold meniscus behavior high frequency magnetic field

Construction of highly antiaromatic boroles

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Science Bulletin 2017年第13期62卷 899-900页

作者： Weidong Zhang Bingjie Zhang Demei Yu gang he School of Science Xi'an Jiaotong University Frontier Institute of Science and Technology Xi'an Jiaotong University

Boroles are five-membered,unsaturated heterocycles with an antiaromatic 4π-electron BC_4 *** to Breslow's exten sion of the H(u|¨)ckel rule,the intrinsic antiaromaticity can be attrib uted to the unfavorableπ-electron delocalization of the BC_4 core,in which a vacant p-orbital on boron mediates the conjugation of four ringπ-*** first borole derivative,1,2,3,4,5-pentaphenylborole[PhBC_4Ph_4],was isolated by Eisch and Hota[1]in 1969,but its crystal structure has been determined by X-ray crystallography recently[2].Since the structure of borole was confirmed。

关键词：芳香性 Lewis酸催化剂 X-射线晶体学硼化合物生物技术领域晶体结构杂环化合物 π电子

Pd-Catalyzed Ortho-Directed C-H Glycosylation of Arenes Using N-linked Bidentate Auxiliaries

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Chinese Journal of Chemistry 2021年第3期39卷 571-576页

作者： Quanquan Wang Wanjun Zhu Qikai Sun gang he Gong Chen State Key Laboratory and Institute of Elemento-Organic Chemistry College of ChemistryNankai UniversityTianjin 300071China

Main observation and conclusion A set of Pd-catalyzed ortho-directed C-H glycosylation reactions with glycosyl chloride donors using various N-linked bidentate auxil-iaries has been developed for synthesis of C-aryglycosides.A broad range of pyranose and furanose moieties can be installed on the ortho position of arylamine,carbazole,indole and benzylamine type substrates in high yield and with high regio-and *** auxiliaries can be readily installed and removed under relatively mild conditions.

关键词： Pd-Catalyzed C-H Bidentate auxiliaries Glycosyl chloride Glycosylation

Calcium-magnesium-alumina-silicate(CMAS)resistant high entropy ceramic(Y_(0.2)Gd_(0.2)Er_(0.2)Yb_(0.2)Lu_(0.2))_(2)Zr_(2)O_(7) for thermal barrier coatings

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Journal of Materials Science & Technology 2022年第12期107卷 259-265页

作者： Shuxiang Deng gang he Zengchao Yang Jingxia Wang Jiangtao Li Lei Jiang Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Center of Materials Science and Optoelectronics Engineering University of the Chinese Academy of SciencesBeijing 100049China Key Laboratory of Bio-Inspired Materials and Interface Sciences Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China

A novel high-entropy material,(Y_(0.2)Gd_(0.2)Er_(0.2)Yb_(0.2)Lu_(0.2))_(2)Zr_(2)O_(7)was successfully synthesized by the solid state reaction method and spark plasma sintering,and investigated as a promising thermal barrier coating ***-earth elements were distributed homogeneously in the pyrochlore *** was found that the prepared high-entropy ceramic maintains pyrochlore structure at the temperature up to 1600℃,and it possesses a similar thermal expansion coefficient(10.2×10^(−6)K^(−1) at 25-900℃)to that of YSZ,low thermal conductivity(he corrosion process was investigated,and RE elements distributing homogeneously in(Y_(0.2)Gd_(0.2)Er_(0.2)Yb_(0.2)Lu_(0.2))_(2)Zr_(2)O_(7)show different diffusion rates in ***^(3+) with a larger radius(closer to Ca^(2+))is easier to react with CMAS to form an apatite phase.

关键词： High-entropy ceramic Pyrochlore structure Thermal barrier coating material CMAS resistance

Aqueous-solution-driven HfGdO_x gate dielectrics for low-voltage-operated α-InGaZnO transistors and inverter circuits

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Journal of Materials Science & Technology 2020年第15期47卷 1-12页

作者： Yongchun Zhang gang he Wenhao Wang Bing Yang Chong Zhang Yufeng Xia School of Physics and Materials Science Radiation Detection Materials&Devices LabAnhui UniversityHefei 230601China Institute of Physical Science and Information Technology Anhui UniversityHefei 230601China College of Mechanical and Electrical Engineering Chuzhou UniversityChuzhou 239000China

In this work,a non-toxic and environmentally friendly aqueous-solution-based method has been adopted to prepare gadolinium-doped hafnium oxide(HfO2) gate dielectric thin *** adjusting the gadolinium(Gd) doping concentration,the oxygen vacancy content,band offset,interface trap density,and dielectric constant of HfGdOx(HGO) thin films have been *** have confirmed that HGO thin films with Gd doping ratio of 15 at.% have demonstrated appropriate dielectric constant of 27.1 and lower leakage current density of 5.8×10-9 A *** indium-gallium-zinc oxide(α-IGZO) thin film transistors(TFTs) based on HGO thin film(Gd:15 at.%) as gate dielectric layer have exhibited excellent electrical performance,such as larger saturated carrier mobility(μsat) of 20.1 cm2 V-1 S-1,high on/off current ratio(Ion/Ioff) of ~108,smaller sub-threshold swing(SS) of 0.07 V decade-1,and a negligible threshold voltage shift(ΔVTH) of 0.08 V under positive bias stress(PBS) for 7200 *** confirm its potential application in logic circuit,a resistor-loaded inverter based on HGO/α-IGZO TFTs has been constructed.A high voltage gain of 19.8 and stable full swing characteristics have been *** a result,it can be concluded that aqueous-solution-driven HGO dielectrics have potential application in high resolution flat panel displays and ultra-large-scale integrated logic circuits.

关键词： Aqueous-solution-driven Low-voltage-operating HfGdOx gate dielectrics Rare earth element doping α-IGZO TFTs

Optimization of electrical performance and stability of fully solution-driven α-InGaZnO thin-film transistors by graphene quantum dots

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Journal of Materials Science & Technology 2023年第10期141卷 100-109页

作者： Xiaofen Xu gang he Leini Wang Wenhao Wang Shanshan Jiang Zebo Fang School of Materials Science and Engineering Anhui UniversityHefei 230601China School of Integration Circuits Anhui UniversityHefei 230601China School of Mathematical Information Shaoxing UniversityShaoxing 312000China

This work presents solution-processed high-performance graphene quantum dots(GQDs)decorated amor-phous InGaZnO(α-IGZO)thin-film transistors(TFTs)based on ZrO x as gate *** with pure IGZO TFTs,GQDs-modifiedα-IGZO TFTs devices with optimized doping content have demonstrated better performances,including a larger field-effect mobility(μFE)of 35.91 cm 2 V^(-1)s^(-1),a higher on/offcurrent ratio(I ON/I OFF)of 5.04×10^(8),a smaller subthreshold swing(SS)of 0.11 V dec^(-1)and a smaller interfacial trap states(D it,1.57×10^(12)cm^(−2)).Moreover,the GQDs-doped IGZO TFTs with a doping concentration of 0.5 mg ml^(-1)have shown excellent stability under bias stress and illumination stress *** demonstrate the potential applications ofα-IGZO TFTs in logic circuits,a resistor-loaded unipolar inverter based on GQDs-IGZO/ZrO x has been integrated,demonstrating good dynamic behavior and a high gain of ***-frequency noise(LFN)characteristics of GQDs-IGZO/ZrO x TFTs have suggested that the fluctua-tions in mobility are the noise *** on all the experimental findings,it can be concluded that solution-processed GQDs-IGZO/ZrO x TFT may envision promising applications in optoelectronics.

关键词： Thin-film transistor α-InGaZnO Graphene quantum dots Stability