Improvement of PDP discharge efficiency based on macro‐cell studies

Abstract— In this paper we explain how macro‐cells (real PDP cells scaled‐up a hundred times) with external and removable electrodes have been validated by comparison with real panels and modeling and used to optimize the luminous efficacy of real PDPs. We illustrate the application of the macroscopic PDP tool to optimize the electrode configuration of short‐gap discharges towards higher luminous efficacy, as well as its use in conjunction with 2D and 3D modeling to lower the operating voltages of high‐efficacy long‐gap discharges triggered by auxiliary electrodes.     

High‐efficacy drive of spatial positive‐column‐discharge PDP with delayed D pulses

Abstract— A thick‐film ceramic‐sheet PDP provides a long sustain discharge gap of 0.45 mm, enabling the use of positive column discharges. The discharges are established in the middle of the discharge space and are completely free from touching the surface of substrates. This allows for the reduction in diffusion losses of the charged particles. To further improve the efficacy, delayed D pulses are applied to the address electrodes during the sustain period. Although the pulses only draw a little current, they perturb the electric field, reducing the peak discharge current and hence resulting in higher efficacy and luminance. The efficacy and luminance increase by 35% and 38%, respectively, with the delayed D pulses. These pulses are incorporated into the contiguous‐subfield erase‐addressing drive scheme for TV application. A short gap of 70 μm between the sustain and data electrodes generates a fast‐rising discharge and allows a high‐speed addressing of 0.25 μsec. This provides 18 contiguous subfields for the full‐HD single‐scan mode, with 70% light emission duty. A luminous efficacy of 6.0 lm/W can been attained using Ne + 30% Xe 47 kPa, a sustain voltage of 320 V, and a sustain frequency of 3.3 kHz, when the luminance is 157 cd/m². Alternatively, the panel can achieve 4.2 lm/W and 1260 cd/m² by increasing the sustain frequency to 33 kHz.     

Discharge analysis of high‐efficacy PDP with a luminous efficacy of 5 lm/W

Abstract— The discharge mechanism concerning the width of the display electrodes in high‐Xe‐content gas mixtures to improve the luminous efficacy of PDPs has been researched. It was found that a luminous efficacy of 5 lm/W was realized for a high‐Xe‐content gas mixture and narrower display electrodes. For a high‐Xe‐content gas mixture, the luminous efficacy increases as the display electrode becomes narrower. This phenomenon was analyzed by observing the emission from a discharge cell. The observation data indicate that a high electron heating efficiency contributes to increased luminous efficacy along with narrow electrodes for a high‐Xe‐content gas mixture as well as high excitation efficiency.     

Performance of the efficacy enhancement layer using nano‐particles in PDPs

Abstract— A nano‐particle dielectric layer was experimentally placed between a conventional dielectric layer and a MgO thin film. This greatly reduces the discharge current and enhances high luminous efficacy. The current reduction might reflect a capacitance reduction in the entire dielectric layer due to the extremely low permittivity of the nano‐particle layer which includes a large amount of space. The luminous efficacy is improved more than what is expected because of the reduction in capacitance. The layer affects the MgO film properties such as crystal growth size, orientation, cathode luminescence, and exo‐electron emission. As a result, it improves the statistical delay in addressing. This might be caused by the large crystal growth of MgO due to the surface roughness of the nano‐particle layer underneath. The particle size required to optimize the roughness of the large growth is about 10–50 nm. The rise in the discharge voltage accompanied by the nano‐particle layer insertion is improved when the layer is properly patterned. A reduction in luminance is prevented when it is patterned in narrow lines along the X—Y gaps while the improvement in address delay strongly depends on the areal ratio of the nano‐particle layer.     

Front address structure for high luminous efficacy and low address voltage in ACPDPs

Abstract— 8‐in. AC plasma display panels with front address (FA) structures were developed. Deep barrier ribs, high‐Xe‐content gas, and long sustain gaps were applied to FA structures to achieve high luminous efficacy. The FA structures have several advantages over conventional structures. Because address electrodes are closer to sustain electrodes, FA PDPs can be driven at lower address voltages, under the condition of deep barrier ribs or high‐Xe‐content gas, than conventional PDPs. A disadvantage of FA PDPs is relatively high capacitance between the sustain electrodes and address electrodes compared to that of conventional PDPs.     

Investigation of the firing voltage in a shadow‐mask PDP

Abstract— A numerical method was used to investigate the firing characteristics of the discharge cell in an AC shadow‐mask PDP (SM‐PDP). The firing voltages for the various discharge paths in the addressing and sustaining periods were calculated, and the effects of the metal barrier rib and the dielectric layer in the discharge cell on the firing characteristics were studied. Furthermore, the advantages of the SM‐PDP in terms of the firing characteristics will be discussed.     

Effects of diamond and AlN layers inserted beneath the phosphor layer on the discharge characteristics of PDPs

Abstract— In this study, the effects of diamond and AlN layers inserted beneath the phosphor layer of the rear plate of a PDP were investigated. The layers were formed via an osmotic‐pressure coating process. Macrocells and test panels were prepared to examine their effects on luminance and luminous efficacy. The results indicate that the layers primarily affect the glow‐discharge behavior and eventually enhance the luminous efficacy of the PDP, suggesting the possibile improvement in the performance of PDPs.     

Effect of small liquid crystal molecules on the driving voltage of cholesteric liquid crystal displays

In order to achieve a lower driving voltage of a cholesteric liquid crystal display (Ch-LCD) we formulated new nematic liquid crystal mixtures with dopants. The interesting thing is that the driving voltage is decreased more by adding the low molecular weight of liquid crystal materials in the cholesteric mixtures without decreasing its reflectivity. The cholesteric mixture is optimized by adding 20 wt% of CN-007 enough to drive the display, necessary for using a commercial STN driver. Homogeneous alignment layers provide a higher reflective panel because of stabilizing the planar texture of cholesteric liquid crystal, while homeotropic alignment layers provide a higher contrast ratio because of stabilizing focal-conic structure. The rubbing condition depending on the driving scheme also affects the panel properties. The combination of the panel structure and the process condition of cholesteric mixtures make the Ch-LCD high reflectivity and contrast ratio. Two 5.7 in. VGA monochromic cholesteric reflective liquid crystal displays with a high resolution like this folding type are demonstrated using a STN driver.     

Effects of shadow‐mask voltage on the discharge in shadow‐mask PDPs

Abstract— A new type of ACPDP with a shadow mask (shadow‐mask PDP, SMPDP) has been developed, featuring an effective structure and lower cost. The distinct difference between an SMPDP and a conventional ACPDP is that the dielectric barrier ribs are replaced by a single metal shadow mask. A three‐dimensional self‐consistent fluid model was used to analyze the effects of the shadow‐mask voltage on the discharge for a simplified driving scheme. The simulation results indicate that by selecting the appropriate shadow‐mask voltage, the addressing speed can be improved due to the local strong electric field. The steady discharge in the sustaining period will not be affected by changes in the shadow‐mask voltages in the addressing period. While in the sustaining period, the shadow‐mask‐voltage variation can directly affect the sustaining discharge. The floating shadow mask in the sustaining period is beneficial in achieving a stable sustaining discharge.     

基于暂态对地电压技术的局部放电传感器的研制

针对开关柜局部放电产生的暂态对地电压（TEV）信号设计了一种局部放电传感器。该传感器由容性耦合、滤波、放大和降频等功能模块组成,具有噪声低、灵敏度高和动态范围宽等优点。测试表明：该传感器能可靠地采集开关柜局部放电产生的暂态对地电压信号。     

Influence of sustaining frequency on the production efficiency of excited Xe atoms studied in unit cell microplasma for ACPDPs using spectroscopic diagnostics

Abstract— The effects of the driving frequency of the sustaining‐voltage pulses on microplasmas in a cell of an ac plasma‐display panel (ACPDP) were investigated using spectroscopic diagnostics [optical emission spectroscopy (OES) and laser‐absorption spectroscopy (LAS)]. The unit discharge cell has a structure similar to that of a general commercial ACPDP, but it is prepared for three‐dimensional (3‐D) observation using a pair of micro‐prisms. When the near‐IR emission by OES and the absorption signal by LAS were observed in the front and side views simultaneously, it was determined that the discharge was concentrated at the center of the discharge space and quickly responded to an applied electrical potential as the sustaining frequency increases. The production efficiency of excited Xe**(2p) atoms and vacuum‐ultraviolet (VUV) photons, which was estimated from the spectroscopy results with the measured power dissipated in the discharges, increased as the frequency of the sustain pulses increases to 100 kHz. At 250 kHz, however, the efficiency remarkably decreased because of an inefficient time for excimer formation and, possibly, for wall‐charge formation. From the quantitative analysis of the efficiency, the most‐efficient frequency for the sustain voltage was around 100 kHz in the case of Xe(5%)‐Ne at 500 Torr, i.e., the efficiency depended on both the priming particles [excited Xe*(1s⁵) atoms] in space and the charged particles on the dielectrics.     

GIS与SVG视域下低压配网单线图的自动化布局算法研究

以设备模型与拓扑连接关系为载体配网单线图自动化布局具备十分重要的现实意义.据此本文在GIS与SVG视域下开发设计了低压配网单线图自动化布局算法.首先分析低压配网单线图自动化成图思路;其次详细设计自动化布局算法;最后进行自动化布局算法实践应用流程规划.研究表明,低压配网单线图可基于移动终端展示,以缩放与平移实时呈现箱内设...     

电传动车辆用高功率锂离子电池性能分析研究

为研究功率型锂离子电池性能,对某35 Ah功率型锂离子电池单体进行了充放电特性试验和分析,由此获得功率型电池在不同温度和不同倍率下的充放电特性、内阻特性和温升特性。研究结果表明,低温下电池的充放电内阻较大,充放电性能衰减显著;常温下电池的内阻较小,充放电温升较小,大电流充放电的容量稳定性好,质量比能量高,作为电传动车辆主要或辅助动力源具有良好的应用前景。     

限定空间无线传感器节点电路低功耗的优化

限定空间无线传感器节点的低功耗分析一直存在成本高、精度低的缺点。在对比总结了传统低功耗电路的原理及特点的基础上,指出了其优缺点。通过具体实验电路加入负反馈,得到了相应的数据并进行对比,得出了较低功率消耗的结论。同时,结合目前的发展情况给出了相应的改进措施。通过对硬、软件结构的剖析,给出了仿真结果,证明此方案具有广阔的发展应用前景。     

Effect of heterogeneity in additively manufactured dielectric structures on RF response of microstrip patch antennas

Microstrip patch antennas with a tunable radiofrequency (RF) response are a great candidate for additive manufacturing (AM) process. First, three separate sets of ABS samples were created at three different machine preset fill densities using an extrusion based 3D printer. Once fabricated, actual solid volume fraction of each set of samples was measured using a 3D X‐ray computed tomography microscope. It is observed that the factory preset fill‐density values are only applied to the core region and actual solid volume fractions for each sample set are different from printer‐preset values. Also, the printed materials appeared to exhibit anisotropy such that the thickness direction dielectric properties are different from the in‐plane properties (planar isotropy). Microstrip patch antennas created on the AM fabricated ABS were tested for resonant frequencies using a vector network analyzer (VNA). The measured resonant frequencies combined with ANSYS‐HFSS simulation were used to estimate bulk dielectric constant of ABS and equivalent dielectric properties in planar and thickness directions. It is observed that the antenna resonant frequency decreases with an increase in core solid volume fraction. Also, in‐plane permittivity appeared to have minimal effect on antenna resonant frequency, while the thickness direction properties have substantial effects.     

Effect of the grain size on hysteresis of liquid‐crystalline Blue Phase I

Abstract— Three different blue‐phase I liquid‐crystal samples with different grain‐size distribution were studied. Polycrystalline platelet grains reflects light in the visible region and have been observed under a polarizing optical microscope. Green and blue grain areas have been measured and then the statistical histogram by the Gaussian distribution function was fitted and the mean grain size was calculated. The effect of hysteresis on grain size has been compared for the three samples. Hysteresis depends explicitly on the grain‐size distribution. Large grain size has revealed less hysteresis, while small grain size depicted pronounced hysteresis.     

探头固定特性对非介入式压力检测性能的影响

基于超声波的非介入式压力检测是利用超声波在容器壁中的传播时延与容器内压有关这一特性来实现压力检测。获得高信噪比的超声波信号和精确的传播时延是提高压力测量精度的关键。本文采用一发两收（一个发射探头、两个接收探头）模式,研究了接收探头固定特性对超声波信号幅值以及传播时延的影响。实验结果表明,随着探头荷载的增加,超声波信号幅值会随之增大并趋于稳定。此外,改变两个接收探头的荷载大小,超声波传播时延也会随之而变化,而且其传播时延改变量和由压力容器内压所引起的传播时延处于同一数量级。因此,在实际应用中应确保两个接收探头固定特性一致,从而提高压力测量精度。     

低温弱光对辣椒生长及光合作用的影响

研究了偏低温弱光条件对两个辣椒品种株高、茎粗和根系等生长发育状况,以及叶面积、叶片中叶绿素含量和净光合速率影响,研究结果表明:低温弱光胁迫使辣椒株高和茎粗增长及叶面积扩展变慢,但低温对植株生长的抑制作用比弱光更明显;低温弱光下辣椒植株根系活力下降;低温弱光胁迫下,叶片中叶绿素含量下降,净光合速率下降。     

SFT中因素间因果概念提取方法研究

为了分析空间故障树中实际故障数据与影响因素之间的因果关系,基于因素空间思想,在空间故障树理论框架内提出一种因素间因果概念的提取方法。针对故障数据分析,将影响元件故障的使用时间和使用温度作为影响因素;将元件故障概率作为目标因素。通过背景关系分析和基本概念半格分析得出影响因素和目标因素之间的因果概念。将理论和实际中概念的外延和内涵统一,使方法兼顾理论和实际。分析结果中包括了三种基本概念：不可再分的基本概念、中间基本概念、不包含故障概率相的概念。前者属于真概念,可用于实例因果概念分析;后两者不能用于实例因果概念分析,只可作为根据影响因素对对象进行分类的概念。     

整车环境下加装散热翅片对轮毂电机散热性能的影响

为提高电动车轮毂电机散热性能,在整车环境下采用CFD数值计算方法,对不同车速下轮毂电机的散热性能进行数值计算并分析;研究加装散热翅片对轮毂电机散热性能的影响,得到轮毂电机的温度场、空气质量流量、外流场和表面对流传热系数.结果表明：电机的最高温度位于定子上,外表面最高温度区域分布在电机的侧面外壳上;在电机侧面外壳上加装散热翅片可以对电机起到较好的降温效果,当翅片长度方向与电机轴中心线成30°夹角时,更加有利于电机的散热.