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一种触摸屏侧面等电阻布线方法
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作者 杨祖声 陶雄 高蕾 《中国集成电路》 2024年第3期44-49,共6页
随着智能手机、pad等触摸式屏幕的流行,触摸屏面板设计成为智能手机设计的重要环节。而触摸屏面板的驱动线网等电阻布线设计在触摸屏设计中有着至关重要的作用,特别是要求在其侧面的狭窄且长宽比比较大的矩形区域内完成等电阻布线,任务... 随着智能手机、pad等触摸式屏幕的流行,触摸屏面板设计成为智能手机设计的重要环节。而触摸屏面板的驱动线网等电阻布线设计在触摸屏设计中有着至关重要的作用,特别是要求在其侧面的狭窄且长宽比比较大的矩形区域内完成等电阻布线,任务困难且繁琐,若单纯依赖人工调整则不仅效率低,还会使得设计周期变长。为此,研究能够快速完成触摸屏侧面矩形区域内的等电阻布线的算法问题是当务之急。本文基于通道切割思想,根据等电阻的要求,对布线线段的电阻建立二次模型,利用罚函数将有约束的二次优化模型转变为无约束的对数目标函数,并利用拟牛顿迭代法对模型进行求解。实验表明,对于30根布线,此方法可以在1秒内完成布线任务,并且布线结果完全满足触摸屏侧面等电阻的要求。 展开更多
关键词 触摸屏 通道切割 等电阻 布线 二次模型
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基于干式平波电抗器的等电阻电压法和等温升法的分析和应用 被引量:4
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作者 陈荣 万锋涛 张晓美 《高压电器》 CAS CSCD 北大核心 2017年第12期215-220,共6页
从直流工程用干式平波电抗器面临的容量、电感、体积重量日益增大的工程实际需要出发,对干式平波电抗器的两种设计方法,即等电阻电压法和等温升法,分别进行理论推导、仿真分析及应用研究,并通过案例验证了两种方法的异同和相关结论,对... 从直流工程用干式平波电抗器面临的容量、电感、体积重量日益增大的工程实际需要出发,对干式平波电抗器的两种设计方法,即等电阻电压法和等温升法,分别进行理论推导、仿真分析及应用研究,并通过案例验证了两种方法的异同和相关结论,对干式平波电抗器设计提供参考性意义。 展开更多
关键词 干式平波电抗器 等电阻电压法 等温升法 温度场
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干式空心电抗器的优化设计 被引量:9
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作者 刘志刚 耿英三 +2 位作者 王建华 武安波 王维平 《高电压技术》 EI CAS CSCD 北大核心 2003年第2期17-18,20,共3页
基于等电阻电压的原理,采用有限元法优化设计空 心电抗器,通过选用不同的优化工具,解决了具有不同安装 方式和不同订货参数的空心电抗器的设计问题。
关键词 干式空心电抗器 优化设计 等电阻电压法 有限元法 目标函数
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基于有限元模型重构的多物理场耦合空心电抗器优化设计 被引量:16
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作者 虞振洋 王世山 《电工技术学报》 EI CSCD 北大核心 2015年第20期71-78,共8页
电抗器是电力系统中最为重要的设备之一,如何便捷地设计并优化该类电抗器已成为工程和学术领域的重要课题。本文将电抗器设计和有限元理论结合起来,通过给定的设计指标以及制造方提供的线规,采用遍历搜索法确定电抗器的初设结构参数,以... 电抗器是电力系统中最为重要的设备之一,如何便捷地设计并优化该类电抗器已成为工程和学术领域的重要课题。本文将电抗器设计和有限元理论结合起来,通过给定的设计指标以及制造方提供的线规,采用遍历搜索法确定电抗器的初设结构参数,以此构建电抗器多物理场耦合有限元模型,求解其"磁场-电路"耦合场来获得电抗器设计优化所需的物理参数,以此代入基于以"层等电阻电压约束"为主、"层等电流密度约束"为辅的邻域搜索优化算法,计算得到优化后的结构尺寸,并按此对电抗器有限元模型进行重构,再次求解,形成一个迭代过程,反复进行该迭代过程,并设定一个收敛条件,最终得到最优解;以磁场求解的各线圈损耗密度为"桥梁",间接将磁场和"温度-流体"场耦合,求解出电抗器各个包封的温升,对所设计优化的结果进行校核。根据算法"重构"特点,采用Ansys软件实现一体化优化设计,以两个电抗器设计优化为例,优化设计结果与设计指标误差在10%以内,显示出该优化设计算法的实用性。 展开更多
关键词 干式空心电抗器 多物理场耦合 模型重构 优化设计 等电阻电压
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Cycle life prediction and match detection in retired electric vehicle batteries 被引量:4
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作者 周向阳 邹幽兰 +1 位作者 赵光金 杨娟 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第10期3040-3045,共6页
The lifespan models of commercial 18650-type lithium ion batteries (nominal capacity of 1150 mA-h) were presented. The lifespan was extrapolated based on this model. The results indicate that the relationship of cap... The lifespan models of commercial 18650-type lithium ion batteries (nominal capacity of 1150 mA-h) were presented. The lifespan was extrapolated based on this model. The results indicate that the relationship of capacity retention and cycle number can be expressed by Gaussian function. The selecting function and optimal precision were verified through actual match detection and a range of alternating current impedance testing. The cycle life model with high precision (〉99%) is beneficial to shortening the orediction time and cutting the prediction cost. 展开更多
关键词 retired electric vehicle battery life prediction model match detection electrochemical impedance spectroscopy equivalent circuit
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A Mapping Technique to Draw Resistivity Isocontours for Slice-of-Silicon Monocrystal 被引量:1
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作者 孙以材 潘国峰 +2 位作者 杨茂峰 叶威 张鹏 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第7期1281-1285,共5页
A resistivity distribution with a space of 3mm between test points was measured on a slice-of-silicon monocrystal (diameter 75mm) using an inclined four-point probe. This paper has determined the number of resistivi... A resistivity distribution with a space of 3mm between test points was measured on a slice-of-silicon monocrystal (diameter 75mm) using an inclined four-point probe. This paper has determined the number of resistivity divisions and their separations by statistical methods and introduced fuzzy mathematics to place the data into different fuzzy sets, after choosing the exponent function as a membership function for fuzzy sets and suitable values of thresholds. One fuzzy set corresponds to one resistivity isocontour. Then,the resistivity isocontours can be drawn with a definite separation and fi- nally shown in a map with MATLAB. The deviation of resistivity data on an isocontour is small and there are few residual test points without connections. So, the connection of the isocontours are high-quality and useful in application for instructing practical production. 展开更多
关键词 mapping technique silicon monocrystal draw the resistivity isocontours
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Influence of Electrolyte on ESR of Medium Voltage Wet Tantalum Capacitors 被引量:3
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作者 刘仲娥 宋金荣 +2 位作者 陈晓静 李忆莲 桂娟 《Transactions of Tianjin University》 EI CAS 2004年第3期163-166,共4页
In this paper, the influence of working electrolyte on high-frequency electrical performance of wet tantalum capacitors is studied. Emphasis is especially put on the study of the contribution of depolariser in reducin... In this paper, the influence of working electrolyte on high-frequency electrical performance of wet tantalum capacitors is studied. Emphasis is especially put on the study of the contribution of depolariser in reducing Equivalent Series Resistance(ESR). According to the theory of depolarization in electrochemistry and the theory of cathode capacitance of electrolytic capacitor, different kinds of depolarisers are added separately into the foregone electrolyte. Then capacitors are assembled with tantalum cores dipped with the compounded electrolytes. The best depolariser and its concentration in the whole electrolyte could be selected according to the test results of the capacitance and ESR of the capacitors. The results of our experiment show that depolariser Fe 2(SO 4) 3 used in working electrolyte of 100 V/100 μF wet tantalum capacitors can help to obtain lower ESR and higher capacitance at frequency from 0.1 kHz to 100 kHz. 展开更多
关键词 depolariser electrical double layer electrical performance
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Surface nanostructure modification of Al substrates by N^+ ion implantation and their corrosion inhibition 被引量:2
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作者 FatemeABDI HadiSAVALONI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第3期701-710,共10页
The influence of implantation of N+ions of different energies on the nanostructure of7049Al substrates and the corrosioninhibition of produced Al samples in a3.5%NaCl solution was studied.The X-ray diffraction(XRD)res... The influence of implantation of N+ions of different energies on the nanostructure of7049Al substrates and the corrosioninhibition of produced Al samples in a3.5%NaCl solution was studied.The X-ray diffraction(XRD)results confirmed the formationof AlN as a result of N+ion implantation.The atomic force microscope(AFM)results showed that grains of larger scale are formedby increasing N+energy which can be due to heat accumulation in the sample during implantation causing higher rate of diffusion inthe sample,hence decreasing the number of defects.Corrosion resistance of the samples was studied by the electrochemicalimpedance spectroscopy(EIS)measurements.Results showed that corrosion resistance of implanted Al increases with increasing N+ion energy.The equivalent circuits for the N+implanted Al samples with different energies were obtained,using the EIS data whichshowed strong dependence of the equivalent circuit elements on the surface morphology of the samples.Finally,the relationshipbetween corrosion inhibition and equivalent circuit elements was investigated. 展开更多
关键词 ion implantation ALUMINUM CORROSION electrochemical impedance spectroscopy equivalent circuit
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Comparison and Analysis of Two Microwave Equivalent-Circuit Models for Resonant Tunneling Diode
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作者 钟鸣 张世林 +2 位作者 郭维廉 梁惠来 毛陆虹 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2004年第11期1370-1375,共6页
The distinction between two microwave equivalent-circuit models,quasi Esaki tunneling model (QETM) and quantum well injection transit model (QWITM),for the resonant tunneling diode (RTD) is discussed in details,and tw... The distinction between two microwave equivalent-circuit models,quasi Esaki tunneling model (QETM) and quantum well injection transit model (QWITM),for the resonant tunneling diode (RTD) is discussed in details,and two groups of circuit parameters are extracted from experiment data by the least square fit method.Both theory analysis and the comparison of fit results demonstrate that QWITM is much more precise than QETM.In addition,the rationality of QWITM circuit's parameters confirms it too.On this basis,the resistive frequency is calculated,whose influence factors and improvement method are simply discussed as well. 展开更多
关键词 resonant tunneling diode microwave equivalent-circuit quantum well injection transit resistive frequency
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Preparation of N‐vacancy‐doped g‐C_3N_4 with outstanding photocatalytic H_2O_2 production ability by dielectric barrier discharge plasma treatment 被引量:11
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作者 Xuhe Li Jian Zhang +4 位作者 Feng Zhou Hongliang Zhang Jin Bai Yanjuan Wang Haiyan Wang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第6期1090-1098,共9页
Dielectric barrier discharge(DBD) plasma is considered to be a promising method to synthesize solid catalysts. In this work, DBD plasma was used to synthesize a nitrogen‐vacancy‐doped g‐C3N4 catalyst in situ for ... Dielectric barrier discharge(DBD) plasma is considered to be a promising method to synthesize solid catalysts. In this work, DBD plasma was used to synthesize a nitrogen‐vacancy‐doped g‐C3N4 catalyst in situ for the first time. X‐ray diffraction, N2 adsorption, ultraviolet–visible spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectrosco‐py, electrochemical impedance spectroscopy, electron paramagnetic resonance, O2 tempera‐ture‐programmed desorption, and photoluminescence were used to characterize the obtained cat‐alysts. The photocatalytic H2O2 production ability of the as‐prepared catalyst was investigated. The results show that plasma treatment influences the morphology, structure, and optical properties of the as‐prepared catalyst. Nitrogen vacancies are active centers, which can adsorb reactant oxygen molecules, trap photoelectrons, and promote the transfer of photoelectrons from the catalyst to the adsorbed oxygen molecules for the subsequent reduction reaction. This work provides a new strat‐egy for synthesizing g‐C3N4‐based catalysts. 展开更多
关键词 Dielectric BARRIER discharge plasma Graphitic carbonnitride H2O2 productionNitrogen VACANCIES PHOTOCATALYSIS
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Electrochemical impedance spectra of V_2O_5 xerogel films with intercalation of lithium ion 被引量:1
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作者 张勇 刘玉文 +1 位作者 程玉山 胡信国 《Journal of Central South University of Technology》 2005年第3期309-314,共6页
Vanadium pentoxide xerogel films used for lithium rechargeable batteries were prepared from crystalline c-V2O5 by melt quenching method,then the electrochemical process of lithium intercalation into vanadium pentoxide... Vanadium pentoxide xerogel films used for lithium rechargeable batteries were prepared from crystalline c-V2O5 by melt quenching method,then the electrochemical process of lithium intercalation into vanadium pentoxide xerogel films was simulated with an equivalent circuit model, which was derived from the mechanism of electrode reactions. Measured electrochemical impedance spectra at various electrode potentials were analyzed by using the complex non-linear least-squares fitting method. The results show that impedance spectra consist of 2 high-to- medium frequency depressed arcs and a low frequency straight line. The high frequency arc is attributed to the absorption reaction of lithium ions into the oxide film, the medium frequency arc is attributed to the charge transfer reaction at the vanadium oxide/electrolyte interface and the low frequency is characterized by a straight line with a phase angle of 45° corresponding to the diffusion of lithium ion through vanadium oxide phase. The experimental and calculated results are compared and discussed focusing on the electrochemical performance and the state of charge of the electrode. Moreover, the high consistence of the fitted values of the model to the experimental data indicates that this mathematical model does give a satisfying description of the intercalation process of vanadium pentoxide xerogel films. 展开更多
关键词 vanadium pentoxide xerogel films electrochemical impedance spectra equivalent circuit melt quenching method lithium rechargeable batteries
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A General Study on Equivalent Resistance of Three-Terminal Ladder Network
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作者 WuGuoxiang TanZhizhong +1 位作者 SongGuohua SongChangqing 《Electricity》 2005年第1期38-40,共3页
In view of the application importance of resistance network in modern science and technology, this paper presents the basic structure of a three terminals ladder shaped resistance network, for which, to study in- dept... In view of the application importance of resistance network in modern science and technology, this paper presents the basic structure of a three terminals ladder shaped resistance network, for which, to study in- depth the equivalent resistance, carry out network analysis by applying virtual current method and construct a model of two elements three orders differential equation. Based on different marginal conditions, two general adaptive rules for the three-terminal ladder shaped inlet resistance, as well as two ultimate rules for the equiva- lent resistance of three-terminal infinite ladder shaped were given. 展开更多
关键词 three-terminal network virtual current equivalent resistance
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Effects of various sintering methods on microstructure and mechanical properties of CP-Ti powder consolidations
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作者 Je-ha SHON Jong-moon PARK +3 位作者 Kyeong-sik CHO Jae-keun HONG Nho-kwang PARK Myung-hoon OH 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第S1期59-67,共9页
Effects of various sintering methods such as spark plasma sintering(SPS), hot pressing(HP) and electric resistance sintering(ERS) on the microstructure and mechanical properties of commercial pure titanium(CP-Ti) powd... Effects of various sintering methods such as spark plasma sintering(SPS), hot pressing(HP) and electric resistance sintering(ERS) on the microstructure and mechanical properties of commercial pure titanium(CP-Ti) powder consolidations with particle size of <147 μm, <74 μm and <43 μm were studied. The smaller particle powders are densified to proceed at a higher rate. Dense titanium with relative density up to 99% is found to take place at 850 °C under 30 MPa of SPS and HP condition. However, in case of ERS, CP-Ti powders were densified almost at 950 °C under 30 MPa. The microstructure of sintered titanium is composed of equiaxed grains at 850-950 °C. The yield strength of sintered body composed of <43 μm powder is 858 MPa by using SPS at 850 °C under 30 MPa. When there is a higher content of small particle, the higher yield strength value is obtained both by using SPS and HP. However, when ERS is introduced, the highest yield strength is 441 MPa at 950 °C under 30 MPa, which shows much lower values than those by SPS and HP methods. ERS method takes much less sintering time compared with SPS and HP. Nevertheless, higher sintering temperature results in lower strength and elongation because of brittle fracture. 展开更多
关键词 CP-Ti powders sintering method spark plasma sintering hot pressing electrical resistance sintering
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The Influence of Generated Pulses Parameters on the Thyratron in the Inductive Energy Storage
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作者 Vereschagin Nikolai Mihailovich Kruglov Sergey Aleksandrovich Serezhin Andrei Aleksandrovich 《Journal of Energy and Power Engineering》 2012年第3期387-390,共4页
Experimental research of anode current and anode voltage influence on the speed of decaying plasma resistance change and the time ofthyratron cutoff. Anode current resistance increase is shown to cause thyratron cutof... Experimental research of anode current and anode voltage influence on the speed of decaying plasma resistance change and the time ofthyratron cutoff. Anode current resistance increase is shown to cause thyratron cutoff time increase in case of fixed anode voltage. In turn anode voltage increase in case of fixed anode current causes earlier increase of decaying plasma resistance growth speed and quicker apparatus cutoff: 展开更多
关键词 VOLTAGE inductive energy storages COMMUTATOR THYRATRON plasma.
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Effects of temperature variation on Li_xFe PO_4/C(0
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作者 肖政伟 张英杰 胡国荣 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第6期2043-2051,共9页
Li Fe PO4/C was prepared via solid state reaction and characterized with X-ray powder diffraction and charge–discharge test. As-prepared Li Fe PO4/C has a triphylite structure and exhibits an excellent rate capabilit... Li Fe PO4/C was prepared via solid state reaction and characterized with X-ray powder diffraction and charge–discharge test. As-prepared Li Fe PO4/C has a triphylite structure and exhibits an excellent rate capability and capacity retention. Electrochemical impedance spectroscopy(EIS) was applied to investigate LixFe PO4/C(0<x<1) electrode on temperature variation. The valid equivalent circuit for EIS fitting was determined which contains an intercalation capacitance for Li+ ion accumulation and consumption in the electrode reaction. The surface layer impedance needs to be included in the equivalent circuit when Li Fe PO4/C is deeply delithiated at a relatively high temperature. EIS examination indicates that a temperature rise leads to a better reversibility, lower charge transfer resistance, higher exchange current density J0 and greater Li+ ion diffusion coefficient for the LixFe PO4/C electrode process. The Li+ ion concentration in LixFe PO4/C is potential to impact the Li+ ion diffusion coefficient, and a decrease in the former results in an increase in the latter. 展开更多
关键词 lithium ion cell LIFEPO4/C el :ctrode process electrochemical impedance spectroscopy equivalent circuit Li+ ion diffusion coefficient
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Adsorption isotherm mechanism of amino organic compounds as mild steel corrosion inhibitors by electrochemical measurement method 被引量:5
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作者 A.Y.MUSA A.A.H.KADHUM +3 位作者 A.B.MOHAMAD M.S.TAKRIFF A.R.DAUD S.K.KAMARUDIN 《Journal of Central South University》 SCIE EI CAS 2010年第1期34-39,共6页
The inhibition ability of 4-amino-5-phenyl-4H-1, 2, 4-trizole-3-thiol (APTT), ethylenediaminetetra-acetic acid (EDTA) and thiourea (TU) for mild steel corrosion in 1.0 moFL HC1 solution at 30 ℃ was investigated... The inhibition ability of 4-amino-5-phenyl-4H-1, 2, 4-trizole-3-thiol (APTT), ethylenediaminetetra-acetic acid (EDTA) and thiourea (TU) for mild steel corrosion in 1.0 moFL HC1 solution at 30 ℃ was investigated. Tafel polarization and electrochemical impedance spectroscopy (EIS) were used to investigate the influence of these organic compounds as corrosion inhibitors of mild steel in 1.0 mol/L HC1 solution at 30 ℃. The inhibition mechanism was discussed in terms of Langrnuir isotherm model. Results obtained from Tafel polarization and impedance measurements are in a good agreement. The inhibition efficiency increases with the increase of the inhibitor concentration. The adsorption of the inhibitors on the mild steel surface follows Langmuir adsorption isotherm and the free energy of adsorption AGads indicates that the adsorption of APTT, EDTA, and TU molecules is a spontaneous process and a typical chemisorption. 展开更多
关键词 corrosion inhibitor Langmuir adsorption isotherm mild steel
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Evaluation of Barley Genotypes for Resistance to Pyrenophora Teres Using Molecular Markers
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作者 Leona Leisova-Svobodova Lenka Stemberkova +1 位作者 Martina Hanusova Ladislav Kuaera 《Journal of Life Sciences》 2011年第7期497-502,共6页
Net blotch disease caused by the fungus Pyrenophora teres belongs to the complex of leaf blotch diseases that decrease the yield and the quality of barley (Hordeum vulgate L.). This study deals with the use of micro... Net blotch disease caused by the fungus Pyrenophora teres belongs to the complex of leaf blotch diseases that decrease the yield and the quality of barley (Hordeum vulgate L.). This study deals with the use of microsatellites localized nearby the quantitative trait loci, associated with the resistance to P. teres to screen barley lines and varieties that could be introduced into a net blotch resistance breeding program. Thirty-five barley microsatellite loci and 65 barley genotypes, 265 alleles were detected. The number of alleles per locus ranged from 2 to 26. The arrangement of genotypes into clusters based on microsatellite data does not correspond to their resistance level to P. teres even though chosen microsatellite markers have been localized nearby QTLs associated with the resistance to P. teres. 展开更多
关键词 BARLEY microsatellites net blotch resistance.
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High tap density of Ni_3(PO_4)_2 coated LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 with enhanced cycling performance at high cut-off voltage
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作者 崔妍 徐盛明 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第1期315-320,共6页
The Li Ni1/3Co1/3Mn1/3O2 is first obtained by the controlled crystallization method and then coated with Ni3(PO4)2particles. The effects of the coating on rate capability and cycle life at high cut-off voltage are inv... The Li Ni1/3Co1/3Mn1/3O2 is first obtained by the controlled crystallization method and then coated with Ni3(PO4)2particles. The effects of the coating on rate capability and cycle life at high cut-off voltage are investigated by electrochemical impedance spectroscopy and galvanostatic measurements. The element ratio of Ni:Mn:Co is tested by inductively-coupled plasma spectrometer(ICP) analysis and it testified to be 1:1:1. It is indicated that Ni3(PO4)2-coated Li Ni1/3Co1/3Mn1/3O2 has an outstanding capacity retention, where 99% capacity retention is maintained after 10 cycles at 5C discharge rate between 2.7 V and 4.6 V. The electrochemical impedance spectroscopy(EIS) results show that the current exchange density i0 of the coated sample is higher than that of Li Ni1/3Co1/3Mn1/3O2, which is beneficial to its electrochemical performances. All the conclusions show that the Ni3(PO4)2coating can prominently enhance the high rate performance of the Li Ni1/3Co1/3Mn1/3O2, especially at high cut-off voltage. 展开更多
关键词 LiNi1/3Co1/3Mn1/3O2cathode material Electrochemistry Ni3(PO4)2coating High tap density High rate discharge capacity
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Constructal optimization of cylindrical heat sources with forced convection based on entransy dissipation rate minimization 被引量:12
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作者 GONG ShuWen CHEN LinGen +2 位作者 XIE ZhiHui FENG HuiJun SUN FengRui 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第4期631-639,共9页
Based on constructal theory and entransy theory,the optimal designs of constant-and variable-cross-sectional cylindrical heat sources are carried out by taking dimensionless equivalent resistance minimization as optim... Based on constructal theory and entransy theory,the optimal designs of constant-and variable-cross-sectional cylindrical heat sources are carried out by taking dimensionless equivalent resistance minimization as optimization objective.The effects of the cylindrical height,the cylindrical shape and the ratio of thermal conductivity of the fin to that of the heat source are analyzed.The results show that when the volume of the heat source is fixed,there exists an optimal ratio of the center-to-centre distance of the fin and the heat source to the cylinder radius which leads to the minimum dimensionless equivalent thermal resistance.With the increase in the height of the cylindrical heat source and the ratio of thermal conductivity,the minimum dimensionless equivalent thermal resistance decreases gradually.For the heat source model with inverted variable-cross-sectional cylinder,there exist an optimal ratio of the center-to-centre distance of the fin and the heat source to the cylinder radius and an optimal radius ratio of the smaller and bigger circles of the cylindrical fin which lead to a double minimum dimensionless equivalent thermal resistance.Therefore,the heat transfer performance of the cylindrical heat source is improved by adopting the cylindrical model with variable-cross-section.The optimal constructs of the cylindrical heat source based on the minimizations of dimensionless maximum thermal resistance and dimensionless equivalent thermal resistance are different.When the thermal security is ensured,the optimal construct of the cylindrical heat source based on minimum equivalent thermal resistance can provide a new alternative scheme for the practical design of heat source.The results obtained herein enrich the work of constructal theory and entransy theory in the optimal design field of the heat sources,and they can provide some guidelines for the designs of practical heat source systems. 展开更多
关键词 constructal theory entransy theory entransy dissipation rate minimization three-dimensional cylindrical heat source generalized thermodynamic optimization
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Catalyst-Free Growth of Nanographene Films on Various Substrates 被引量:12
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作者 Lianchang Zhang Zhiwen Shi +3 位作者 Yi Wang Rong Yang Dongxia Shi Guangyu Zhang 《Nano Research》 SCIE EI CAS CSCD 2011年第3期315-321,共7页
We have developed a new method to grow uniform graphene films directly on various substrates, such as insulators, semiconductors, and even metals, without using any catalyst. The growth was carried out using a remote ... We have developed a new method to grow uniform graphene films directly on various substrates, such as insulators, semiconductors, and even metals, without using any catalyst. The growth was carried out using a remote plasma enhancement chemical vapor deposition (r-PECVD) system at relatively low temperatures, enabling the deposition of graphene films up to 4-inch wafer scale. Scanning tunneling microscopy (STM) confirmed that the films are made up of nanocrystalline graphene particles of tens of nanometers in lateral size. The growth mechanism for the nanographene is analogous to that for diamond grown by PECVD methods, in spite of sp2 carbon atoms being formed in the case of graphene rather than sp3 carbon atoms as in diamond. This growth approach is simple, low-cost, and scalable, and might have potential applications in fields such as thin film resistors, gas sensors, electrode materials, and transparent conductive films. 展开更多
关键词 NANOGRAPHENE CATALYST-FREE plasma enhancement chemical vapor deposition (PECVD) transparent and conductive film
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