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PREPARATION OF MULTI-WALLED CARBON NANOTUBEs UsING NiO CATALYsT sYNThEsIZED BY hYDROThERMAL METhOD

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Acta Metallurgica sinica(English Letters) 2003年第5期16卷 416-420页

作者： Y.J.Zhu Y.L.Chen X.M.Xue Y.M.Chen C.Y.Wu T.C.Kuang s.h.li h.Y.Zhang DepartmentofAppliedPhysics GuangdongUniversityofTechnologyGuangzhou510090China CenterofAnalysisTesting GuangdongUniversityofTechnologyGuangzhou510O9OChina FacultyofMaterialandEnergy GuangdongUniversityofTechnologyGuangzhou510090.China

The Ni(Oh)2/siO2 binary colloid was prepared using Ni(NO3)2.6h2O and (C2h5O)4siO4 as starting materials and was used to form NiO/siO2. composite powder by hydrothermal method and desiccant method in open air respectively. Multi-walled carbon nanotubes (MWCNTs) were synthesized respectively by chemical vapor deposition using the NiO/siO2 catalyst prepared by different methods. The phase and morphology of the catalysts and the morphology, output yield and purity of MWCNTs were compared by XRD, TEM and sEM. The results show that the catalyst powder prepared by hydrothermal method, compared with that by desiccant method, is smaller, better dispersion and has stronger catalytic activity. Pure MWCNTs with smaller tube diameter and narrow range could be obtained at a high yield using that NiO/siO2 powder prepared by hydrothermal method as catalyst.

关键词： hydrothermal method dry method at atmosphere carbon nan- otube catalytic pyrolysis

Three-Phase switch-Mode Rectifier Constructed using single-Phase Modules

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Three-Phase Switch-Mode Rectifier Constructed using Single-P...

2002年IEEE十区计算机、通信、控制和电机工程会议

作者： s.h.li h.Y.Tsai C.M.liaw Department of Electrical Engineering National Tsing hua University hsinchu Taiwan China Department of Electrical Engineering National Tsing hua University hsinchu Taiwan China Department of Electrical Engineering National Tsing hua University hsinchu Taiwan China Ph.D. Member IEEE

A three-phase (3φ)switch-mode rectifier(sMR)constructed using single-phase (1φ) modules ispresented in this paper. The AC sides of three modulesare △-connected, with proper control, good powerquality iu line drawn currents under well-regulatedDC output voltage is obtained. As one module faultoccurs,the proposed 3φsMR becomes *** the worst case, when two constituted 1φmodulesare faulted, the proposed 3φsMR will be operated as1φsMR to continuously supply regulated DC voltageoutput. As to the control aspect, the dynamic model ofthe 3φsMR under nominal operating condition isestimated. And accordingly, a feedback controller isdesigned to meet the given voltage regulation controlspecifications. Then a robust controller is furtherdeveloped to reduce the control performancedegradation due to the changes of operating conditionand number of connected modules.

关键词： sMR Three-Phase switch-Mode Rectifier Constructed using single-Phase Modules

An Empirical Model of Leakage Current in Poly-silicon TFTs

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An Empirical Model of Leakage Current in Poly-silicon TFTs

2007亚洲显示国际会议

作者： W.J.Wu R.h.Yao Y.F.hu s.h.li Institute of Microelectronics south China University of Technology Guangzhou 510640 China

＜正＞Based on an approximate expression for generation rate,an empirical model for poly-si TFT leakage current is devel- oped in this *** this model,the leakage current is composed of two sections :the leakage current induced by vertical electric field in the overlap region and that induced by lateral electric field in the lateral depleted *** proposed model is analytical without numerical integration,hence attractive for circuit *** addition,it is suitable for po- ly-si TFTs either before or after *** model has been verified by a good agreement between simulated results and experimental data.

关键词： Poly-si TFT Modeling Empirical Model Leakage Current

Editorial for the special Issue on Emerging Technology and Advanced Application of Nondestructive Detection for Power Equipment

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Chinese Journal of Electrical Engineering 2024年第1期10卷 1-2页

作者： li J. Mei h. li s. Tianjin University China Tsinghua shenzhen International Graduate school China Lanzhou Jiaotong University China

The rapid development of clean and renewable energy technologies represented by wind and solar energy,as well as the continuous growth of load demand,have put forward higher requirements for the safe operation of the power *** performance of power equipment based on traditional dielectric materials is often limited by various defects generated during molding,transportation,assembly,and operation,which cannot meet the reliability requirements of power systems in the new *** detection is an essential technical method in industrial development,which can detect and evaluate the defect and damage status of in-service equipment,key components,and materials without damaging the object.

关键词： service Application operation

NUCLEATION AND GROWTh OF ＜111＞ ORIENTATION hOMOEPITAXIAL DIAMOND MONOCRYsTAL

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NUCLEATION AND GROWTH OF ＜111＞ ORIENTATION HOMOEPITAXIAL D...

sixteenth Congress of the International Union of Crystallography

作者： Z.M.Zhang s.h.li Q.Y.Cai h.M.Chen X.C.he D.L.ling s.J.Wang Z.W.hu s.s.Jiang C.Z.Ge N.B.Ming shanghai Jiao Tong Univ. Nanjing Univ.

＜正＞It has been reported that only polycrystal diamond film could be formed on beteroepitaxial substrate by CVD method,which stimulated great interesting to grow homoepitaxial film,however, few reports concerned the growth on ＜111＞ oriented *** this paper,a successful growth of homoepitaxy on（111） natural diamond substrate is presented by using microwave PCVD method. The experimental process was almost same as that of（100） homoepitaxy reported before.

关键词：

AN INVEsTIGATION ON（100）MONOEPITAXIAL DIAMOND MONOCRYsTALliNE FILMs

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AN INVESTIGATION ON（100）MONOEPITAXIAL DIAMOND MONOCRYSTALL...

sixteenth Congress of the International Union of Crystallography

作者： Z.M.Zhang s.h.li Q.Y.Cai h.M.Chen X.C.he D.L.ling s.J.Wang Z.W.Wu s.s.Jiang C.Z.Ge N.B.Ming shanghai Jiao Tong Univ. Nanjing Univ.

＜正＞For diamond’s excellent microelectrical properties and the rapid development of CVD techniques, the diamond high temperature semiconductor materials have been received increasing *** our work,we have obtained quite smooth homoepitaxial monocrystalline films deposited on（100） oriented hT-hP synthesized diamond by microwave PCVD *** microwave frequency was 2.45 Ghz,internal dimension of the quartz horizontal reaction tube was 35mm the reaction gases were acetone and hydrogen,

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Fast efficient photon deceleration in plasmas by using two laser pulses at different frequencies

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Matter and Radiation at Extremes 2024年第3期9卷 11-18页

作者： Y.X.Wang X.L.Zhu s.M.Weng P.li X.F.li h.Ai h.R.Pan Z.M.sheng Key Laboratory for Laser Plasmas(moe) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IFsA Shanghai Jiao Tong UniversityShanghai 200240China Research Center of Laser Fusion of China Academy of Engineering Physics MianyangSichuan 621900China state key Laboratory of high Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Tsung-dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

The generation of ultrashort high-power light sources in the mid-infrared(mid-IR)to terahertz(Thz)range is of interest for applications in a number of fields,from fundamental research to biology and *** conventional laser technology,photon deceleration in plasma wakes provides an alternative approach to the generation of ultrashort mid-IR or Thz ***,we present a photon deceleration scheme for the efficient generation of ultrashort mid-IR or Thz pulses by using an intense driver laser pulse with a relatively short wavelength and a signal laser pulse with a relatively long *** signal pulse trails the driver pulse with an appropriate time delay such that it sits at the front of the second wake bubble that is driven by the driver *** to its relatively long wavelength,the signal pulse will be subjected to a large gradient of the refractive index in the plasma wake ***,the photon deceleration in the plasma wake becomes faster and more efficient for signal pulses with longer *** greatly enhances the capacity and efficiency of photon deceleration in the generation of ultrashort high-power light sources in the long-wavelength IR and Thz spectral ranges.

关键词： laser ultrashort photon

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热轧方形中空截面的残余应力分析

钢结构(中英文) 2009年第6期 83-84页

作者： s.h.li,G.Zeng,Y.F.Ma,Y.J.Guo and X.M.Lai

残余应力对热轧构件的受力性能和强度有很大影响。主要分析了热轧方形中空截面的残余应力。超过600部文献或文章的记载表明,可以使用X射线衍射法分析沿厚度方向的外表面和内表面的残余应力。试验结果对该截面残余应力的量级和分布分析... 详细信息

残余应力对热轧构件的受力性能和强度有很大影响。主要分析了热轧方形中空截面的残余应力。超过600部文献或文章的记载表明,可以使用X射线衍射法分析沿厚度方向的外表面和内表面的残余应力。试验结果对该截面残余应力的量级和分布分析提供了数据。最大的残余应力产生在焊缝上,沿厚度变化的残余应力分布呈现出双线性特性。同时发现,方形截面残余应力的形成过程对其外表面纵向残余应力分布影响很大。

关键词：残余应力热轧 X射线衍射法形成过程

Tribological behavior of lubricant-impregnated porous polyimide

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Friction 2024年第4期12卷 711-725页

作者： Jinbang li Ningning ZhOU Janet s.s.WONG school of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211China Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms Beijing Institute of Control EngineeringBeijing 100029China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

Porous materials impregnated with lubricants can be used in conditions where limited lubricant is *** this work,three porous polyimides(PPI)with different densities were ***(PAO)impregnated PPI(iPPI)discs were rubbed against steel and sapphire *** operando observations of the iPPI-sapphire contacts show that oil is released under an applied load,forming a meniscus around *** at the outlet is created at high sliding *** amount of released oil increases with increasing PPI *** moduli,E*,estimated based on the actual contact size show that trapped oil in iPPIs contributes to load *** higher speeds,tribological rehydration of the contact occurs in low density iPPI,with that E*rises with *** high density PPIs,high speeds give a constantly high E*which is limited by the viscoelastic properties of the PPI network and possibly the rate of oil *** of iPPI-steel contacts is governed by the mechanical properties of the PPI,the flow of the lubricant,and the roughness of the PPI *** low-and medium-density(highly porous,high roughness)PPIs,large amount of oil is released,and lubrication is mainly via lubricant restricted in the contact in the pores and possibly tribological *** high density(low porosity)PPI,with lower roughness,hydrodynamic lubrication is achieved which gives the lowest *** results show that polymeric porous materials for effective lubrication require the optimization of its surface roughness,stiffness,oil flow,and oil retentions.

关键词： polyimide porous material friction mechanism polymer limited lubrication