丝网印刷碳纳米管显示器驱动电路的研制

为解决采用丝网印刷技术制作的碳纳米管显示器件(CNT-FED)驱动电压高、亮度均匀性差的问题,设计并实现了电压控制的寻址与显示分离型的驱动电路.采用分离高压控制器件实现了行、列驱动电压波形,并利用反向高压控制暗像素点,不仅能满足丝网印刷CNT-FED 700~1 000 V的高压驱动要求,并且有效抑制了漏电流导致的串亮现象.在各行电路上设计了限流电阻,对场发射电流起到反馈作用,有效改善了亮度均匀性.该驱动电路成本低,且从电路角度提升了丝网印刷CNT-FED的亮度和发光均匀性.测试结果表明:由新电路驱动的CNT-FED可实现动画显示,峰值亮度可达到1 400 cd/m2.     

用机械破碎方法提高印刷碳纳米管薄膜的场发射性能

提出了一种可显著改善丝网印刷碳纳米管(CNTs)薄膜场发射特性的后处理方法,用机械压力通过隔离层对附着于CNTs表面的无机物进行原位破碎,并用高速气流清洁薄膜表面.同其他方法相比,机械破碎方法既不会在处理后的阴极表面留下残留物,也不会使薄膜受损.场发射特性测试表明,与未处理薄膜相比,经过处理的CNTs薄膜的开启场强从2.7V/μm降低到1.7V/μm,同样面积的薄膜(印刷面积为40mm×40mm)在4.2V/μm场强下的发射电流由70μA提高到了950μA,说明机械破碎处理对于提高薄膜的场发射特性有明显作用.该方法在碳纳米管场发射显示器的制作中具有很好的实际应用价值.     

丝网印刷ZnO纳米锥的浆料制备及场发射特性研究

针对现有的丝网印刷碳纳米管薄膜需要各种后处理工艺才能改善其场发射特性的问题,提出了一种不需任何后处理的丝网印刷ZnO纳米锥的浆料配制工艺.该工艺以羧甲基纤维素为制浆剂,以水为溶剂,所制备的ZnO纳米锥薄膜表面上的有机浆料已基本分解,ZnO纳米锥在高温下既不会弯曲也不会团聚,且成本低,工艺简单.场发射特性测试表明,ZnO纳米锥与制浆剂质量比为3∶5的薄膜在电流密度为0.01 A/m^2时,最低开启场强为2.25 V/μm,在4 V/μm场强下,阳极荧光粉的发光点亮度高且分布均匀.该工艺在ZnO纳米锥场发射显示器的制作中有很好的实际应用价值.     

碳纳米管阴极场发射平板显示器的真空封装

通过采用传统的网版漏印工艺和低熔点玻璃焊料封接技术,实现了场发射显示器真空平板封装,这种封装稳定、可靠且成本低廉,同时,配套的弹性阴极装配技术,可以方便地对不同材料的阴极进行组装,形成二极管结构的场发射平板显示器,弹性装配技术 具有通过拼接得到大面积阴极的潜力,采用这套技术,已经研制出碳纳米管阴极场发射显示器样品。     

基于丝网印刷大面积碳纳米管阴极场发射的研究

针对碳纳米管(CNT)阴极场发射均匀性这一关键难题，根据CNT场发射理论制备了一种新型碳纳米管阴极印刷浆料．实验表明：质量分数约为20％的纯化CNT与4．2％的导电氧化物粘接材料混合形成的印刷浆料，其阴极具有较佳的发射均匀特性．用丝网印刷技术制作成的大面积(对于线长度大于12．5cm)阴极，再经过快速烧结技术及两步后处理工艺，既能除掉粘接材料又能使CNT很好地与衬底固定，并使碳纳米管部分直立和充分暴露，进一步改善了发射均匀性．该均匀发射的阴极开启场为2．0V／μm，在电场强度为2．5V／μm下，电流密度为35mA／mm^2，发光亮度为300cd／m^2，场发射电流稳定，其波动性小于4．5％．该阴极可望应用于场致发射显示器，液晶显示的背光源、电光源等器件。     

碳纳米管/纤维阴极场发射平板显示器研制

探索了从碳纳米管/纳米纤维（CNT/CNF）的制备到CNT/CNF阴极场发射平面显示器(c-FED)封装的工艺流程.用化学气相沉积方法,优化制备条件获得了纯度较高的CNT/CNF;以 CNT/CNF和低压荧光粉为原料,采用丝网印刷工艺制作显示器的阴极和阳极;采用类真空荧光显示器的封装工艺封装了c-FED样管.所研制的c-FED具有优良的场发射性能,较好的均匀性及发光密度,黄色荧光粉的c-FED在电场为 2.7 V/μm时的亮度可达600 cd/m².因该显示器使用普通玻璃作为阴阳极基板,整个工艺流程在大面积和实用化方面有很好的应用潜力.      

三极平板显示器的高真空封装

结合高温烧结工艺和低熔点玻璃粉封接技术,实现了三极结构碳纳米管阴极的场致发射显示器的高真空平板封装．这种封装稳定可靠且成本低廉,具有良好的器件密封性能．已经研制出三极结构的碳纳米管场致发射显示器样品,所研制的样品具有良好的栅极控制特性以及比较高的显示亮度．     

丝网印刷碳纳米管显示器灰度失真的研究

通过研究两级结构丝网印刷碳纳米管显示器(CNT-FED)引线电极的线性分压问题,发现电极的线性电阻导致不同像素点间存在0.2%的电场偏差,引起8位元(256级)灰度显示中的24级灰度被湮没.为解决电极引线引起的灰度图像显示失真的问题,提出了一种CNT-FED电极的改造方法,通过改进屏内部引线电极和增加阴极反馈电阻,使像素点间的等效电阻值偏差从总电阻值的0.2%减小到0.0003%,且抑制了发射电流的波动,增加了像素点的过流保护.计算和仿真结果显示,新电极消除了256级灰度显示的失真,有效提高了CNT-FED的发光均匀性.     

新型圆柱结构的场发射碳纳米管发光管

设计了一种新型结构的场发射碳纳米管发光管，采用热解法直接生长在钨丝上的碳纳米管作为发光管阴极，获得了新的碳纳米管生长工艺．扫描电子显微镜的表面形貌分析表明，钨丝上碳纳米管的顶端有许多分叉．在常温且真空度为10-4Pa的条件下，测试了钨丝上碳纳米管的电流-电压发射特性，测得开启电场强度为1．25V／μm左右．当电场强度为2．0V／μm时，电流密度可迭320A／m^2．测试了发光管的发光特性，当电压为300V时，亮度可达1600cd／m^2．这种低成本、低耗能、高亮度的新结构碳纳米管发光管，有效地提高了场发射效率和发光亮度，可用于交通指示和大屏幕显示器．     

碳纳米管场发射器件放气特性分析及其对场发射性能的影响

为了研究场发射冷阴极电流跌落机制,采用四极质谱仪实时分析的方法研究了碳纳米管阴极场发射器件的放气特性及工作状态下器件内残余气体对阴极场发射性能的影响.结果表明:碳纳米管阴极场发射器件工作时,放出气体的主要成份是H_2,CO_2,CO;随着阴极发射电流密度的增加,气体成份的分压也随着增加.碳纳米管阴极的场发射性能,例如开启场强、阈值场强和场发射电流密度都与放出气体压强密切相关.碳纳米管阴极在压强为2.1×10~(-3)Pa的残余气体环境下工作1.5 h后,开启场强和阈值场强相应增加了29.4%和50.0%.阴极受残余气体影响,一方面阴极发射材料表面功函数增加;另一方面阴极发射体场增强因子减小.增大的功函数和减小的场增强因子降低了阴极的场发射性能.因此,场发射器件放气是阴极电流跌落的重要原因.     

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.     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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