液晶显示屏(LCD)用三醋酸纤维素(TAC)薄膜的发展现状与前景

本文阐述了三醋酸纤维素(TAC)薄膜的一些最新发展情况。三醋酸纤维素薄膜作为片基(0.12-0.14毫米厚)应用于制作照相胶片已有多年,近年却作为偏光板的支持体(0.04-0.08毫米厚),大量应用于制作液晶显示屏LCD,代替长期以来一直应用的阴极射线管CRT,由于其不产生对人体有害的射线,因而问世后大受欢迎,更因质量迅速提高,生产技术日益成熟,成本显著下降,故其生产规模和市场发展极为迅速。     

用于液晶显示的透明导电膜

采用低衬底温度射频溅射的方法制得了低电阻率、高透过率的透明导电膜，沉积时的氧分压、衬底温度等对透明导电膜有很大的影响．衬底温度为室温时，制出了４．５×１０－４Ω·ｃｍ的透明导电膜．在彩色滤色膜或保护膜上沉积透明导电膜时，只能在低于它们的耐热温度以下，并注意排除有机膜吸附的气体．     

LED分区背光光扩散性能研究

液晶显示器的区域动态调光技术中,各分区背光确定后,为了保证背光降低后的亮度和显示效果,需要对液晶像素进行精确补偿。本文采用低通滤波方法模拟LED背光源在背光模组中传播时的扩散过程,得到光扩散函数模板参数,进而得知各像素的实际背光亮度,据此对液晶像素进行精确补偿。在直下式LED分区背光液晶显示系统上,通过具体图像验证了该方法的准确性。该方法采用常见的测试设备,可操作性强,精度高。经验证,背光分区为32个时,32个分区的相对误差平均值为6.41%。在动态区域调光液晶电视样机中实现了本文的扩散方法,和没有调光的电视相比,节能率达到27.06%,画面无拖尾现象。     

基于LTPS制程工艺的LCD/OLED显示用玻璃基板发展综述

随着显示行业高端消费品的发展要求,LTPS成为目前显示领域炙手可热的先进技术,但是由于国外技术封锁,国内全部依赖进口,因而我们必须自主研发,提升综合竞争力。本文基于平板显示最新发展动态和研发热点,综述了高分辨率LCD/OLED显示产品所用LTPS制程工艺种类与特点,以及LTPS制程工艺对玻璃基板的理化性能要求,其中,玻璃基板耐热性、热膨胀系数、紫外透过率、弹性模量是十分关键的技术指标;论述了溢流法生产工艺和浮法生产工艺所生产的LTPS玻璃基板的优势与劣势;总结了美国和日本开发满足LTPS制程工艺的玻璃基板产品状况;讲述了我国尚未形成技术和产业突破,亟须加大对LTPS制程工艺的玻璃基板的研发投入和产业探索的现状。     

Precedence constrained TSP arising in printed circuit board assembly

Component placement sequencing is a challenging problem that arises in automated assembly of printed circuit boards. While for some placement machines all placement sequences are acceptable, in other cases some sequences are not allowed because of the shape of the placement head. In such cases, while the head moves down to perform a placement, it might damage a previously placed component, and the problem of determining a minimum cost and at the same time acceptable sequence leads to a Precedence Constrained Travelling Salesman Problem formulation. In this study, a solution procedure to such a formulation is developed and its implementation in a real PCB assembly environment is discussed.     

Advances in the display quality of dye-doped polymer-dispersed liquid crystal films by addition of disc-shaped multidirectional light-control film

Typically, the addition of a dye is considered to increase the contrast ratio (CR) of a polymer-dispersed liquid crystal (PDLC) display; however, with the addition of a small amount of dye, the contrast ratio (CR) unexpectedly decreased as compare to the CR of a normal white PDLC display, attributed to various reasons. In this study, an additional multidirectional light scattering polymer film is developed over a conventional dye-doped polymer-dispersed liquid crystal (DPDLC) film to enhance the CR. For this, a disc-shape (DS) pattern on PN393 film is coated. This structure is believed to enhance the scattering properties of DPDLC displays via multiple-directional scattering nature of DS pattern film. Fabrications of such devices are simple and have advantageous of its low-cost production. This optimal designed disc-shaped light-scattering (DSS) film resulted in the enhancement of the CR of the DPDLCs.     

An evaluation framework for product planning using FANP,QFD and multi-choice goal programming

Technological innovation and satisfaction of customer needs are the keys to survival and success for firms, especially in global competitive high-tech industries. Since new products are usually a source of new sales and profits, the success of new product development (NPD) is essential to maintain a competitive edge and to make a decent profit in a longer term. Therefore, how to develop products that deliver the quality and functionality customers demand while generating the desired profits becomes an important task for the manufacturers. In this paper, a framework with two phases is constructed for facilitating the selection of engineering characteristics (ECs) for product design. In the first phase, quality function deployment (QFD) is incorporated with the supermatrix approach of analytic network process (ANP) and the fuzzy set theory to calculate the priorities of ECs with the consideration of the interrelationship among factors and the impreciseness and vagueness in human judgments and information. In the second phase, multi-choice goal programming model is constructed by considering the outcome from the first phase and other additional goals, such as NPD cost and manufacturability, in the attempt to select the most suitable ECs. A case study of the product design process of backlight unit (BLU) in thin film transistor liquid crystal display (TFT-LCD) industry in Taiwan is carried out to verify the practicality of the proposed framework.     

Optical enhancement of dye-doped PDLC by additional dye-LC layer coating

Dye-doped PDLC has a high probability to be used as reflective optical shutter due to its good reflectance compared to normal PDLC or LC shutter structures. The black state can be significantly enhanced by the minimized surface scattering between polymer and LC surface, which makes a harmful result to the contrast ratio, one of most important factors for optical shutter. To remove this scattering effect, we have developed new combinational structure, consisted of guest dye-doped LC (DLC) and dye-doped PDLC (DPDLC). In the newly fabricated dye-doped PDLC structure, the front location of dye-doped LC layer can remove the light scattering effect of the surface of single dye PDLC structure. The proposed process can also remove the randomly distributed dyes in polymer area of dye PDLC. This technique enhances the reflectance as well as the contrast ratio.     

中小型钢铁企业生产物流分段管理模式及其应用

分析了中小型钢铁企业生产物流管理存在的普遍问题和生产物流的特点,建立以CPFR思想指导的生产物流管理规范和例外事件处理机制。应用JIT和MRPⅡ二种现代生产管理理论,构建了一套针对中小钢铁企业的生产物流推-拉分段管理模式:以MRPⅡ为主线,采用推式生产模式,进行连续生产阶段的生产计划的制定和生产物流控制;以JIT为主线,采用拉式生产模式,进行离散生产阶段的生产物流控制。X集团应用效果表明了该模式对生产物流相关指标改善的有效性。     

用FDTD分析小尺度波纹对KDP近场光强分布的影响

采用SPDT方法加工获得的KDP晶体表面所残留的小尺度波纹对其激光损伤阈值有着重要影响.利用时域有限差分方法(FDTD)研究了KDP晶体已加工表面存在的小尺度波纹对晶体内部近场光强分布的影响.通过对数值模拟结果的分析发现:表面残留的小尺度波纹,会使晶体内部的衍射场发生畸变,导致晶体内部光强沿横向和纵向呈现周期性的强弱分布;当小尺度波纹周期小于0.7μm时,其对晶体内部光强的调制作用很小,此时光强以倏逝波的形式在波纹附近产生调制;1.064μm时相对光强迭到最大值;3μm后基本保持不变,相对光强随着小尺度波纹幅值的增加基本成线性增长,不同周期时增长幅度不同.     

RTM工艺注模过程模拟的有限元/控制体积方法和流动分析网络技术比较

分析了有限元/控制体积方法和流动分析网络技术两种算法的区别,结果表明:在三角形网格上两种算法是一致的,在矩形网格上流动分析网络技术(FAN)相对于传统的有限元/控制体积方法(FE/CVM)可以构造更精确的控制体积表面流率计算方案。算例研究表明:对于矩形网格流动分析网络技术预测的填充时间精度比传统的有限元/控制体积方法提高几倍左右。      

A review of production planning and control: the applicability of key concepts to the make-to-order industry

The paper reviews ‘classic approaches’ to Production Planning and Control (PPC) such as Kanban, Manufacturing Resource Planning (MRP II) and Theory of Constrains (TOC), and elaborates upon the emergence of techniques such as Workload Control (WLC), Constant Work In Process (CONWIP), Paired cell Overlapping Loops of Cards with Authorization (POLCA) and web- or e-based Supply Chain Management (SCM) solutions. A critical assessment of the approaches from the point of view of various sectors of the Make-To-Order (MTO) Industry is presented. The paper considers factors such as the importance of the customer enquiry stage, company size, degree of customization and shop floor configuration and shows them to play a large role in the applicability of planning and control concepts. The paper heightens the awareness of researchers and practitioners to the PPC options, aids managerial system selection decision-making, and highlights the importance of a clear implementation strategy. WLC emerges as the most effective Job Shop solution; whilst for other configurations there are several alternatives depending on individual company characteristics and objectives. The paper outlines key areas for future research, including the need for empirical research into the use of Workload Control in small and medium sized MTO companies.     

传感监测LCM成型厚铺层结构增强体内部渗透性能研究

采用传感监测系统辅助对厚铺层结构纤维增强体内部流动情况进行了实验研究.结果表明:渗透率随铺层厚度的增加逐渐减小,并趋于平缓;测试液在铺层厚度增强体顶层和底层渗透存在一定量的差异,并随铺层厚度的增加而增大.在不影响结构要求的前提下,导流布与长丝毡的配合使用是改善厚铺层结构渗透性能的有效方法.     

Holographic grating formation in PVB doped polymer dispersed liquid crystal based on PUA

Different contents of poly(vinyl butyral) (PVB) have been incorporated into the conventional holographic polymer dispersed liquid crystal (HPDLC) composition based on liquid crystal mixture and polyurethane acrylate (PUA) with a particular composition. As the PVB content is increased, the hardness, elastic modulus and thermal stability of polymer matrix are improved because of the entanglement by PVB, which has a relatively high molecular weight compared with PUA oligomer. Diffraction efficiency is enhanced with the addition of PVB except for HPDLC film with 10 wt.% PVB owing to augmentation of the phase separation between polymer and LC, caused by the increase of elasticity of the polymer matrix. However, the increase in viscosity on adding PVB produces a slow saturation time and coalescence of the LC droplet, showing a lower diffraction efficiency at the PVB content of 10 wt.% than at 0 wt.%.     

高温氢气退火提高硅片质量的研究

研究了硅片高温氢气退火的工艺技术,实验显示,在高温1150℃,在高纯氢气氛中退火处理至少60min,在硅片表面产生约50μm以上的洁净层。测试了退火后硅片中氧的深度分布,发现硅片表面有一层低氧区,能提高硅片的质量,使氧化层错的密度降低一个数量级,测试数据还表明高温氢退火对降低COP缺陷的密度和提高氧化层的质量也有一定的效果。     

基于相控阵激光超声的裂纹衍射增强试验研究

针对超声衍射时差法(TOFD)存在检测精度较差、区域检测可靠性不够和信号信噪比(signal-to-noise ratio, SNR)低等问题,提出了一种基于光纤皮秒激光器和高速旋转镜的相控阵激光超声裂纹检测方法。利用有限元方法模拟热弹机制,建立二维瞬态激光超声力-固耦合模型产生横波与纵波在缺陷处发生的衍射现象,分析了裂纹尖端不同奇异点、声波不同中心频率和相控阵激励源不同位置对声波衍射的影响,通过衍射信号的信噪比和位移幅值两个计算指标来分析变化规律,并进行了试验验证。结果表明:数值模拟与试验结果有较好的一致性,相控阵激光源较传统单束激光源对衍射信号幅值和信噪比有明显的增强作用,纵波衍射信号信噪比较理想;衍射信号幅值随裂纹尖端奇异点增加和声波中心频率减小而增大;信噪比随尖端奇异点增加而增大,随声波中心频率一定范围增加无明显变化,随激光源距离的增加呈现先增加后减小的趋势;缺陷定量分析时计算出的裂纹长度与实际裂纹的误差均不超过6.8%。