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981.
Polarization State Evolution in Fibre Polarization Transformer Influenced by Phase Difference 总被引:1,自引:0,他引:1
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In accordance with the intrinsic structure of controllably-spun birefringent-fibre-based fibre polarization transformer (FPT), the Jones vector is calculated from point to point along the polarization transforming fibre by the cascade differential phase retarder model. It is the first time using this concise method to examine the phasedifference effect on the evolution of state of polarization (SOP) inside this special fibre component. Both the extinction ratio and orientation angle of SOP are calculated to give out a whole evolution history from linear polarization light at the slow spun end into circular polarization light at the fast spun end, and vice versa. The influence of phase-difference is discussed on the polarization transforming performance and further referential conclusion is provided for design and test of the FPT component. 相似文献
982.
Theoretical Analysis of Current Crowding Effect in Metal/AIGaN/GaN Schottky Diodes and Its Reduction by Using Polysilicon in Anode
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There exists a current crowding effect in the anode of AIGaN/GaN heterojunction Schottky diodes, causing local overheating when working at high power density, and undermining their performance. The seriousness of this effect is illustrated by theoretical analysis. A method of reducing this effect is proposed by depositing a polysilicon layer on the Schottky barrier metal. The effectiveness of this method is provided through computer simulation. Power consumption of the polysilicon layer is also calculated and compared to that of the Schottky junction to ensure the applicability of this method. 相似文献
983.
Effect of Ⅲ/Ⅴ Ratio of HT-AIN Buffer Layer on Polarity Selection and Electrical Quality of GaN Films Grown by Radio Frequency Molecular Beam Epitaxy 总被引:1,自引:0,他引:1
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We investigate the effect of A/N ratio of the high temperature (HT) AIN buffer layer on polarity selection and electrical quality of GaN films grown by radio frequency molecular beam epitaxy. The results show that low Al/N ratio results in N-polarity GaN films and intermediate Al/N ratio leads to mixed-polarity GaN films with poor electrical quality. GaN films tend to grow with Ga polarity on Al-rich AIN buffer layers. GaN films with different polarities are confirmed by in-situ reflection high-energy electron diffraction during the growth process. Wet chemical etching, together with atomic force microscopy, also proves the polarity assignments. The optimum value for room-temperature Hall mobility of the Ga-polarity GaN film is 703cm^2/V.s, which is superior to the N-polarity and mixed-polarity GaN films. 相似文献
984.
Chalcogenide Random Access Memory Cell with Structure of W Sub-Microtube Heater Electrode 总被引:2,自引:0,他引:2
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In order to reduce the reset current of cllalcogenide random access memory; a W sub-microtube heater electrode with outer/inner diameter of 260/100nm, which was fabricated with standard 0.184-μm technology, is proposed for the first time to achieve a reset current of about 0.5 mA. The reasons may be that sub-microtube increases the number of electrode edge and thermal efficiency is improved greatly because the thermal density on the edge of sub-microtube electrode is generally the highest. 相似文献
985.
986.
987.
A new rhodium(Ⅱ)porphyrin complex was isolated by chromatography from the photochemical reac-tion of(μ—tetraphenylporphyrinato)bis[dicarbonylrhodium(Ⅰ)]with pyridine in benzene and has been charac-terized.From the results,the reaction mechanism is proposed. 相似文献
988.
非接触体积测量实验系统 总被引:1,自引:0,他引:1
将物体体积参量测量转变成气体压力测量,可以实现体积非接触测量.本文设计了非接触体积测量实验系统,并分析了系统测量的分辨率及精度. 相似文献
989.
990.
本文求出了Eliashberg方程在T=Tc时的解,得到了下面的临界温度级数表示式:Tc=α0(μ*)(λ〈ω2〉)1/2{1+1/λα1(μ*)〈ω4>/〈ω2>2+1/λ2(α21(μ*)〈ω6>/〈ω2>3+α22(μ*)〈ω4>2/〈ω2>4) +1/λ3(α31(μ*)〈ω8>/〈ω2>4+α32(μ*)(〈ω4>〈ω6>)/〈ω2>5)+α33(μ*)〈ω4>3/〈ω2>6+…},其中α0(μ*),α1(μ*)等仅是μ*的函数。新的Tc公式表明了,Tc不仅依赖于λ、μ*和〈ω2〉,而且依赖于有效声子谱α2F(ω)的各级矩〈ω2n〉。 相似文献