Charge distribution in polyethylene/ethylene vinylacetate laminatesand blends

The formation of space charge in polyethylene/ethylene vinylacetate copolymer (PE/EVA) laminates was investigated using a pulsed electroacoustic (PEA) method. The formation of heterocharge was observed in PE while positive charge (holes) was distributed over the EVA specimen. In the laminates, however, a large amount of charge accumulates at the interface between PE and EVA, resulting in an increase of the electric field in the PE layer. When the thickness of the EVA layer is smaller than that of the PE layer, negative charge dominates in the PE layer due to enhanced charge injection caused by the increased electric field in the PE layers. When these polymers are blended, the amount of heterocharge in the PE/EVA blends varies inversely with the vinylacetate content by the enhancement of homocharge trapping at PE/EVA interfaces and/or by the enhancement of charge injection via an increased electric field in the PE component     

Charge behavior in polyethylene-ionomer blends

In order to explain a decrease of thermally stimulated current (TSC) at high poling fields, the behavior of space charge in two types of polyethylene (PE)/ionomer blends, PE/Surlyn 1652 and PE/Surlyn 1601, has been investigated by measuring the charge distributions and conduction characteristics. PE/Surlyn 1601 blends showed smaller current densities at high electric fields than PE/Surlyn 1652 blends. A considerable amount of negative charge was found to migrate into the bulk region of PE/Surlyn 1601 blends upon discharging, which was attributed to the strong electron affinity of ionic clusters existing only in Surlyn 1601. This migration of charge made the charge distribution uniform, resulting in a decrease of TSC at high poling fields. This phenomenon was not found in PE/Surlyn 1652 blends     

Space charge in polyethylene/ionomer blends

Measurements of thermally stimulated currents were made on ionomer/polyethylene blends. The objective of this work was to study space charge formation in these materials. Two ionomers were compared; both ionomers contained methacrylic acid, neutralized by zinc in one and by sodium in the other. A large current peak centered near 60°C was observed in all blends and associated with the motion of space charges injected into the blends during poling. All blends accumulated large negative space charge concentrations. The approach to the equilibrium space charge distribution (negative and spatially uniform in all blends) is much more rapid in the blends containing the sodium ionomer than in the blends containing the zinc ionomer     

The PC/video connection

The personal computer (PC) is an integral part of our life. Television (TV) and PCs have a common origin in electronic technology. With respect to pictures and sound, TVs are an analog technology; PCs are digital. The analog video signal can be converted to digital information for storage in the computer memory or displayed on the computer monitor. An example of advancing technology is the video conferencing industry (remote conferencing). It is becoming an alternative to expensive and time-consuming air travel. The video and audio are transmitted using complex equipment, and expensive and relatively scarce high bandwidth satellite channels. Combined, video and computing can take technology even further, for instance into the operating room. Video can be used with a computer for teleconferencing the surgery. This would be especially beneficial in the area such as laparoscopy. A video used with the computer provides two distinct advantages. The ability to interact with a remote viewer (e.g. teleconferencing an operation), and the improved instructional value. We consider the state-of-the-art technology that video and computing can create and use. To do this, each aspect of each technology is reviewed     

Charge transfer between a polymer particle and a metal plate due toimpact

To elucidate the mechanism of contact-impact electrification of insulating particles, the authors measured the charge generated by collision of a single polymer particle onto a metal plate. It was not exclusively the normal component of the impact velocity that determined the amount of impact charging. In order to investigate this great contribution of the impact angle to the impact charging, impact stresses, contact times, and contact areas were measured, and the impact-contact process was discussed. Based on the idea that the “apparent contact area” is supported by some “real contact points” and that the number of these real contact points increases with the particle slipping, a new model called “effective contact area model” was proposed     

变频调速系统在ABS/SAN生产线上的应用

大庆乙烯三期工程ＡＢＳ／ＳＡＮ装置上采用了集散控制系统（ＤＣＳ）控制的变频调速系统。介绍了该系统在生产控制过程中的应用,并对其在应用中存在的问题进行了分析。     

Bending piezoelectricity in SAN and ABS copolymer films

The bending piezoelectric coefficients β₃₃₁ have been calculated (~1.5, 8.3, 10.0 μm) for various cases of unstretched and stretched, unpoled and corona poled, films of SAN. For the ABS films the value of β₃₃₁~2.6 nC/m was obtained for unstretched and unpoled film, and 4.4 nC/m for corona poled films. A linear relation between β₃₃₁ and d₃₁ for the heat-treated samples indicates that the major contribution to bending piezoelectricity comes from the dipolar polarization     

PIO-32/32L(PCI)在低压电器试验中的应用

在中心试验室的设备改造中，运用PIO-32／32L(PCI)板来替代老式的欧姆龙程序控制器，实现了低压电器试验中央控制、可靠性、降低了检验人员的劳动力、提高了试验的工作效率。     

PC/104在微弱信号检测中应用

文中介绍基于PC/104的微弱信号数控检测仪器的整体设计与实现。论述引用PC/104后,在总体实现过程中所克服的诸多干扰问题,最后给出在最高灵敏度量程下的实际测量值与理论值的比较,证明本方法的正确性和有效性。     

Charge storage at the Pt/YSZ interface

The electrochemical behavior of Pt/YSZ electrodes in oxygen containing atmosphere at 450 °C has been investigated by double-step chronoamperometry and programmed linear sweep cyclic voltammetry. The response of the O₂(g),Pt/YSZ system in these experiments could be separated into a time dependent and a steady state contribution, the former being dominated by pseudocapacitive processes. It is proposed that Pt–O type species were stored via different processes at three different locations in the O₂(g),Pt/YSZ system: (1) Build-up of a platinum oxide monolayer at the Pt/YSZ binary interface. (2) Formation of Pt-O species at the triple phase boundary and their spreading-out along the Pt/gas interface. (3) Growth of the platinum oxide layer from the binary Pt/YSZ interface toward the bulk of the platinum electrode.     

PC/104通用外围接口电路设计

文中介绍PC/104模块及其外围接口电路设计,并讨论该接口电路所需要考虑的电平匹配、功率驱动以及抗干扰问题,最后还进行相应的软件设计,并将所设计接口电路用于某设备的开关量检测,实践证明工作状态良好.     

智能电网中电动汽车充放电模式的风险评估

电动汽车充放电是智能电网与用户互动的重要组成部分,尽管这种互动模式能够使电网获得经济和社会效益,但同时也面临潜在的运营风险。建立了V0G和V2G两种不同充换电模式下电动汽车对电网影响的收益模型;通过对模型中相关变量的不确定性分析,得到各变量的随机概率分布特性;最后以风险价值(VaR)和条件风险价值(CVaR)作为风险度量指标,采用蒙特卡罗模拟法计算出不同置信度下电网收益模型的风险指标值。介绍了仿真结果。     

触摸屏在蓄电池充放电自动控制中的应用

触摸屏作为一种界面友好、可操作性强的人机交互接口,在蓄电池充、放电自动控制中具有重要作用,本文介绍了蓄电池充、放电自动控制系统中触摸屏的软、硬件设计、工作过程及系统功能。     

上海电动汽车家庭用户端充放电模式的研究

电动汽车的智能充放电管理是智能电网建设的重要内容之一。对智能电网下电动汽车家庭用户端的充放电模式进行研究,建立了电动汽车用户以最小化费用为目标的充放电模式的数学模型,以上海市电动汽车家庭为例,分析基于当前上海电网销售电价下的电动汽车家庭用户端的最优充放电模式,为电动汽车的充放电管理提供了理论依据。     

基于空间电荷的纳米MgO/LDPE中电荷输运的计算方法研究

为定量分析研究纳米氧化镁(MgO)/低密度聚乙烯(LDPE)复合介质的空间电荷行为,将粒径20 nm的纳米MgO颗粒以不同浓度填充到LDPE,并对纳米复合介质的空间电荷分布进行了实验研究。通过空间电荷实验的结果,对其进行多种方法的计算分析,计算分析结果表明:1)浓度为0.5wt%和2wt%的积累空间电荷的平均体电荷密度最大,而浓度1wt%的纳米MgO/LDPE的平均体电荷密度最小;2)浓度为2wt%的纳米MgO/LDPE的视在迁移率和体电荷密度衰减速率最高,其次是浓度为0.5wt%的,最低的是浓度为1wt%的纳米复合介质;3)浓度为1wt%的纳米MgO/LDPE的陷阱深度最大,其次是浓度为0.5wt%的,而陷阱深度最小的是浓度为2wt%的纳米Mg O/LDPE;4)浓度为2wt%的纳米MgO/LDPE试样中的场强畸变最大,其次是浓度为1wt%的,而场强发生畸变幅度最小的是浓度为0.5wt%的纳米MgO/LDPE。     

LiBOB/PC电解液形成SEI膜的过程

利用电化学交流阻抗谱(EIS),结合充放电测试,研究了双草酸硼酸锂(LiBOB)/PC电解液在NG7石墨电极表面形成SEI膜的过程和对应的电位区间.LiBOB/PC在NG7石墨电极表面形成SEI膜是一个连续的过程,在电池的首次放电过程中,1.75 V(vs.Li/Li )放电平台对SEI膜的形成有重要的影响;首次放电至0.55 V左右,SEI膜基本形成;在0.20 V以下放电区间,SEI膜得到了较大程度的完善.     

CB/LDPE纳米复合材料的空间电荷抑制特性

采用熔融共混法制备了纯低密度聚乙烯(LDPE)试样和纳米炭黑(CB)颗粒质量分数分别为0.01%、0.03%、0.05%、0.07%的CB/LDPE复合试样。采用扫描电子显微镜观察纳米CB颗粒在LDPE基体中的分散性,并利用电声脉冲法(PEA)测试各试样在常温和-40 kV/mm条件下的空间电荷积聚特性和陷阱特性,讨论纳米CB颗粒提升LDPE基体空间电荷抑制特性的机制。结果表明:相较于纯LDPE试样,CB/LDPE复合试样的空间电荷积聚特性得到了显著改善,其中CB质量分数为0.03%的CB/LDPE复合试样具有最佳的空间电荷抑制效果。纳米CB颗粒提高了复合试样内部的深陷阱密度,这是提高复合试样空间电荷抑制能力的关键。     

提高镉镍电池快充能力的途径

介绍了提高镉镍蓄电池快速充电能力的一些方法。结合作者的经验，从镍电极、镉电极、电池结构及充电制度等方面提出了一些具体措施和建议。     

开发基于P/PC的实时通讯程序

介绍了Ｐ／ＰＣ的硬件特性,操作系统和开发平台,并详细阐述了如何开发基于Ｐ／ＰＣ的实时通讯程序。