有浮动电极PDP单元放电串扰的数值模拟研究

利用二维流体模拟方法研究等离子体显示屏(PDP)大维持电极间隙单元之间的放电串扰现象.研究发现当维持电极间隙较大时,无论它们之间是否有浮动电极,均可能发生相邻单元之间的放电串扰;同时,串扰还与工作电压有关,电压越高越容易发生串扰.模拟结果显示,串扰仅发生在最初几个维持放电脉冲期间.在单元之间插入浮动电极,可以有效地阻止单元之间的放电串扰而不影响Xe放电激发效率.     

一种新的五电极交流等离子体显示板触发驱动方法

为了降低五电极交流等离子体显示板(AC PDP)的维持放电电压,提出了一种新的触发驱动方法.该方法利用2个辅助间隙内放电过程相互独立的特性,在触发期间采用单个辅助间隙进行触发放电以提高主维持间隙的壁电压.二维流体模拟结果表明,新的触发驱动方法可将五电极AC PDP主维持间隙的壁电压提高30 V左右,从而使其维持电压降低了10~20 V,降低了对驱动电路的要求,同时真空紫外辐射效率比传统三电极AC PDP提高了50%以上.     

电极结构对等离子体显示单元放电效率的影响

利用实验和数值模拟方法研究等离子体显示屏放电单元中的电极间隙、长度、壁障高度等不同参数对放电特性的影响.结果表明,放电效率随电极长度、间隙大小的增大而增大,壁障的存在也使效率略有增加并导致单元有效电容减小,但对放电电压影响很小.单元高度对放电效率影响不大,但可以降低同样间隙下的放电电压.合理选择电极结构可以在较低的维持电压下获得较高的放电效率.     

维持电压对彩色交流等离子体显示器光电参量的影响

为了改善彩色交流等子体显示器（AC－PDP）的性能，采用静态测量法研究了维持电压脉冲幅度和频率对彩色AC－PDP着火电压，熄火电压，维持电压余度，平均放电电流，亮度，发光效率和白场色度等光电参量的影响。结果表明，随着维持电压幅度和频率（12.5-50kHz)的提高，等离子体显示器平均放电电流和亮度增加，白场色度基本保持不变，而发光效率降低；分析得出导致发光效率降低的主要原因是；Xe原子的自吸收现象和荧光粉的受激辐射饱和。因此，在确定驱动波形时，应在使显示器图像显示稳定的前提下，兼顾其亮度，发光效率，功耗和寿命，合理选择维持电压幅度和频率。     

三电极结构荫罩式PDP的模拟和实验研究

采用三维流体模型和老炼测试平台从理论模拟和实验测试角度研究三电极结构荫罩式PDP在对向放电和表面放电驱动波形下的放电发光特性.模拟结果表明:三电极结构荫罩式PDP在对向放电驱动波形下的点火和维持电压都低于表面放电驱动波形下的点火和维持电压;对向放电驱动波形的峰值亮度比表面放电驱动波形约高89％,表面放电驱动波形的放电效率比对向放电驱动波形约高9.1％.老炼平台的实验测试结果也表明了同样的趋势.     

五电极等离子体显示板触发放电的研究

采用流体模型研究了一种五电极交流等离子体显示板(AC PDP)的单点触发放电过程及其真空紫外线(VUV)的辐射特性.数值模拟结果表明,在放电期间恰当地调整电极上的驱动电位,可以改变介质层表面电荷积累,获得较高的壁电压.通过数值模拟还获得了五电极AC PDP维持放电期间的VUV辐射效率,其中173 nm的VUV辐射占总真空紫外辐射效率的27%,有利于提高AC PDP的发光效率.     

铝衬底微等离子体阵列的制作与光电特性测量

在铝衬底上采用光刻工艺制作了带有氧化铟锡(ITO)透明电极的微等离子体阵列,实验研究了该微等离子体阵列在30～100 kPa氖气中的放电特性和发光特性.不同微腔尺寸的微等离子体阵列实验结果表明,对于微腔直径为150μm的器件,击穿电压随着工作气压的升高先下降后上升,并且在53.2 kPa时达到最小值212 V.通过对微腔直径为50μm和30μm器件的击穿电压比较发现,在气压较低时,微腔尺寸大的器件更容易击穿,当气压较高时,微腔尺寸小的器件更容易击穿,并且微腔尺寸小的器件随着气压的升高击穿电压下降得更快.与目前商业等离子体显示器件(PDP)的击穿电压相比,微腔器件的击穿电压更低,而且在高气压下,采用更小的微腔作为PDP的显示单元,可以提高PDP的分辨率.     

基于数值模拟的非对称荫罩式PDP结构参数的优化

为了研究荫罩式等离子体显示板(SMPDP)的放电效率,采用流体模型,建立了二维非对称SMPDP单元的放电模型,给出了放电效率的计算方法.利用该放电模型,研究了具有长放电路径的非对称SMPDP的放电过程,讨论了扫描电极和放电单元后开口等结构参数对非对称SMPDP放电效率的影响.数值模拟的研究结果表明:随着扫描电极向后开口方向延伸长度的增加,非对称SMPDP放电效率先增加后减小,即扫描电极的延伸长度存在最优值;扫描电极与后开口的距离的不同,扫描电极结构不同的非对称SMPDP其放电效率的变化趋势也不同;随着荫罩后开口长度的增加,非对称SMPDP的放电效率呈现先增加后减小的趋势,当荫罩后开口长度为有效后开口长度的60%时,非对称SMPDP的放电效率提高10%.将扫描电极向后开口方向适当延伸,并合理选择后开口的长度、扫描电极与后开口间的距离,可以有效提高非对称SMPDP的放电效率.     

AC-PDP结构对串扰的影响

采用二维数值模拟的方法计算了表面放电型PDP在不同结构下相邻3个显示单元的放电过程.研究了放电过程中各单元内电子、氙谐振态浓度分布和其平均浓度随时间的变化情况.在流体模型计算基础上,采用蒙特卡罗模型对单元内大量谐振光子的辐射、捕获过程进行模拟跟踪,从而得出各放电单元内所产生谐振光子在荧光粉层上的分布.研究了放电过程中相邻单元之间的影响,结果表明,对传统条形障壁结构,单元内维持电极间距增大,放电空间高度增加会使放电串扰和发光串扰加强,Waffle型障壁结构不仅能提高放电效率,而且能有效阻止串扰的发生.     

壁电荷对ACPDP中气体击穿电压的影响

用电容平衡法测量ACPDP宏放电单元在维持放电期的壁电荷变化,并根据宏放电单元壁电荷电压和外加最小维持电压的测量结果计算实际施加在放电气体上的击穿电压,探讨壁电荷电压对放电气体实际击穿电压的影响.实验结果表明:随着ACPDP外加最小维持电压的增加,壁电荷电压升高,气体的击穿电压也随之升高;有壁电荷时的气体击穿电压明显高于无壁电荷时的气体击穿电压,随着壁电荷电压从7.62 V升高到67.89 V,有壁电荷时的气体击穿电压比无壁电荷时的气体击穿电压分别提高了6.98 V到57.09 V;壁电荷增加会显著提高了放电气体的击穿电压阈值,使ACPDP内放电气体的击穿变得困难.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with