共挤法制备突变型PMMA塑料光纤的研究

本文探讨了共挤法制备突变型PMMA塑料光纤的材料选择、生产设备与工艺,讨论了影响PMMA塑料光纤性能的工艺因素,制备出损耗为200～800dB/km的塑料光纤。     

领先的光纤光缆技术——光缆网络变革趋势

一种采用１６芯光纤带的高密度光缆目前已经被研制出来,光纤带由涂覆层很薄的仅为２００μｍ的光纤组成。对于１６芯和８０芯单模光纤连接器而言,平均光损耗分别达到０．２和０．３５ｄＢ。光缆接续时间已减少到目前需要的１／５。通过对纤芯和包层材料的粘度匹配,减少了光纤的结构不完整损耗。经过改变沿光缆长度方向的布里渊频移,光缆的有效输入功率提高了７ｄＢ。     

新一代短距离高速通信用塑料光纤

本文综述了新一代短距离高速通信用塑料光纤的材料、制造、性能和应用方面的最新研究成果。     

光纤在高压输电中的应用

介绍了光控晶闸管触发原理及其触发光路设计方案,对整个光路的功率分配情况进行了计算。阐述了MSC的工作原理,分析了MSC选型原则。衰减设计是触发光路设计的重要组成部分,将塑料光纤用于衰减,使用较短光纤即可得到需求的衰减量,平衡了晶闸管触发光功率和触发回检光功率。     

高速度高强度的光纤拉丝技术

评论了光纤的高速拉丝和涂覆技术,并给出了相应的工作。讨论了在高拉制速率下光纤拉力对二氧化硅光纤光学和机械特性的影响。解释了以工艺变量为依据的高速涂覆装置的涂覆机理。介绍了高速涂覆光纤的最新成就。     

渐变型塑料光纤的制备方法分析

渐变型塑料光纤(GI POF)具有芯径大、柔韧性好、易安装、成本低、抗冲击强度高、抗电磁干扰、无电磁辐射、高带宽等特点,成为局域网以及光纤到户的首选材料。GI POF的制备方法有直接挤出法和预制棒拉纤法,本文将对以上两种方法分别加以综述,最终得出制备GI POF的最佳工艺路线。     

电力光纤通道复用保护

1光纤知识简介 光纤为光导纤维的简称,由直径大约为0．1mm的细玻璃丝构成。光纤作为继电保护的通道介质。具有不怕超高压与雷电电磁干扰、对电场绝缘、频带宽和衰耗低等优点。继电保护所用光纤为通信光纤．是由纤芯和包层两部分组成的：纤芯区域完成光信号的传输,包层则是将光封闭在纤芯内,并保护纤芯,增加光纤的机械强度,如图1所示。     

光纤传感元结构材料对其温度响应的影响研究

光纤传感元的结构形式和材料组成会影响温度作用下光纤的实际变形,从而影响其具体传感特性.理论分析并推导了温度作用下涂覆光纤和套塑光纤实际变形的表达方程式,定义了对应具体光纤结构的等效热膨胀系数.建立了涂覆光纤和套塑光纤的有限元仿真计算模型,具体研究了各层材料间沿轴向和径向的应力和变形分布规律.在此研究基础上分析了涂覆光纤光栅以及干涉型光纤传感器的温度响应公式的具体表达形式,研究结果同样适用于其它各类本征型光纤传感器的温度响应分析.     

光纤端头涂覆层处理技术对出光效果的影响

为提高光纤的出光效果,保证光纤照明系统的可靠性,本文采用涂覆层处理技术对光纤端头进行处理,并通过照度计测量光纤的出光照度,通过对比分析,得出结论:端头剥去一定长度的涂覆层的光纤可以提高光纤照明系统的出光效果。     

几种新型通信光纤的性能分析及应用

为了增加光纤类型，进一步提高光纤性能，以高性价比的产品满足不同类型网络的需求，光纤研究人员正在积极开展对光纤材料、制造工艺、性能测试的研究。文章根据2004年国际线缆会议报道，介绍了最新研制出的几种光纤产品，重点介绍了宽带光传输用非零色散位移单模光纤G.656．其特点是工作波长范围可扩展到S、C和L波段，从而能实现密集波分复用的宽带光传输。另外，介绍了塑料光纤POF，与传统的石英玻璃光纤相比，POF具有制造简单、芯径大、连接方便等优点，受到人们的青睐。     

基于塑料光纤的CAN总线设计

CAN是一种双线实现数据交换的串行通信总线,由于具有实时性好、可靠性高、抗干扰能力强、传输距离远、通信速度快等许多优点,CAN在各种工业自动化控制系统中得到了广泛的应用。塑料光纤有着较玻璃光纤更好的传输特性和光电转换特性。文章将上述两项技术结合到一起,介绍了一种以塑料光纤作为通信介质,以DSP芯片TMS320LF2407A为微控制器的CAN总线通信监控系统,阐述了系统的硬件电路设计和CAN通信软件实现,该系统在工业监控系统中得到了成功的应用,并取得了满意的效果。     

Polymer modified hematite nanoparticles for electrophoretic display

Hematite nanoparticles (Fe₂O₃) as a red inorganic pigment were encapsulated with poly (methyl methacrylate-co-acrylamide) (PMMA-co-AAM) for application in the electronic paper display. Since the Fe₂O₃ nanoparticle has relatively high density (ρ?=?5.07 g/cm³), it usually causes severe sedimentation problem in the suspending medium. In order to reduce density mismatch between inorganic pigment and dielectric medium, the Fe₂O₃ nanoparticles were modified by dispersion polymerization method. Zeta potential and electrophoretic property of the inorganic pigment coated with copolymers in a low dielectric medium were investigated by using electrophoretic light scattering. The surface morphology and molecular structure of the fabricated particles were measured via SEM and FT-IR, respectively. The amount of polymeric coating was also examined by using TGA.     

基于塑料光纤的用电信息采集系统研究与设计

阐述了塑料光纤（plastic optical fiber,POF）的特点,分析用电信息采集系统对于通信的典型要求,提出了一种基于 POF的全光纤用电信息采集系统的设计方案。此方案结合 POF和石英光纤两种光纤的优势,将二者分别用于本地通信和远程通信,可使智能电表与主站之间实现实时通信,具有可靠性高、功耗低、投资相对较小的优点。对于智能电表集中安装的城区以及电力光纤到户的智能小区,这是一种用电信息采集的理想方案。     

光纤CAN-USB接口设计与实现

组建了一种新型星形光纤CAN总线网络。采用塑料光纤(POF)作为传输介质。为存储、处理、调整和优化CAN网络中各参量,设计了光纤CAN总线转USB接口,结合便携式PC机,建立了基于光纤CAN网络的实时数据记录系统。本文重点介绍了光纤CAN总线转USB接口的硬件设计,并详细给出了该接口的驱动程序。     

三芯海底电缆中光纤与缆体应变关系的有限元分析方法

为了利用分布式光纤应变传感技术测量的光纤应变反映三芯光纤复合海底电缆的缆体应变,通过有限元方法进行了建模、求解和分析。通过合并导体屏蔽、绝缘屏蔽、半导体阻水层、填充层,忽略黄铜带、铠装垫层、外被层,对模型进行了简化;选用SOLID164单元对模型进行了动力学分析;施加匀速载荷对海缆进行了拉伸仿真试验。利用最小二乘法对铜导体、XLPE、铅护套、钢丝铠装与光单元的应变进行了拟合,获得了它们的函数关系式。模型求解结果满足弹塑性材料特性,可为研究海底电缆的力学性能、判断海底电缆工作状态提供参考。     

PMMA/PVDF复合物形成的不同形貌聚合物膜

通过对成膜过程的控制,可形成不同形貌的聚甲基丙烯酸甲酯(PMMA)/聚偏氟乙烯(PVDF)凝胶聚合物膜.通过共混成膜的方法,得到无孔共混膜;通过先成膜再交联的方法,得到稀孔交联膜;通过先交联再成膜的方法,得到多孔交联膜.它们的离子电导率顺序为:多孔交联膜>无孔共混膜>稀孔交联膜.采用多孔交联膜的原理型电池以0.2 C在3.0～4.3V充放电,第50次循环时的容量保持率大于92%.     

Development of a portable diagnostic apparatus for coil insulatorsin low-voltage induction motors

When most organic insulators are exposed to thermal stress, they turn darker in color. The increase of electronic transition absorption due to thermal oxidation of the resin is responsible for this darker coloration. A correlation between the degree of aging of these insulators and their reflective absorbances in the near IR (infrared) wavelength range has been established previously. In this paper, a novel non-destructive diagnostic apparatus using an optical fiber sensor developed to evaluate the aging of thermally deteriorated insulators is reported. The key point of this technique is measuring the change of reflective absorbance ratio at two different wavelengths. The sensor consists of two plastic optical fibers (for light transmitting and receiving), a plastic optical coupler, two kinds of near-IR light emitting diodes as light sources, and an optical power meter as a detector, and hence is very compact and lightweight (<2 kg). The aging of an insulator can be estimated using the diagnostic curve, which is obtained by an accelerated heating experiment using model pieces. We applied this measurement technique to predict the residual life of low-voltage induction motors used in elevators     

Narrow-beam aluminum-mirrored fiber optical-taps with controllabletapped power

A fiber optical-tap has been fabricated and tested. Two separate fiber tips were polished with an angle of 45°, and one of the tips was coated with aluminum inside a vacuum deposition unit. Then, the coated and uncoated polished tips were spliced together using a fusion splicer to form a fiber optical-tap. The power of the tapped light is controllable by controlling the thickness of the aluminum coating during vacuum deposition. As the aluminum coating thickness increases, the amount of tapped light increases and consequently the power transmitted after the fiber optical-tap decreases. For the same aluminum coating thickness, the tapped beam power from a single-mode fiber tap is higher than that from a multimode fiber tap. In addition to the feasibility of tapping a narrow light beam and controlling its power, the fabricated optical tap has a short length, which means that it can be integrated easily in optical signal-processing circuits. The mechanical strength of the tap has been tested in the laboratory and found to be capable of supporting between 75 and 180 g before breaking     

基于塑料光纤的自动抄表系统的设计与实现

使用塑料光纤实现自动抄表的本地通信,能够很好的弥补石英光纤接口问题和RS-485的布线繁琐问题.文章阐述了自动抄表的整体结构,提出了在自动抄表系统本地通信网中采用塑料光纤来实现集中器模块和采集模块之间的数据传输,并具体介绍了对两模块的功能和工作方式流程,最后选择AT指令协议实现其软件功能.     

Development of optical fiber technology in Japan

The developments of optical fiber technology in Japan are reviewed. Multicomponent glass optical fibers, pure silica-core single-mode fibers, dispersion-shifted fibers, rare-earth-doped optical fibers, polarization maintaining fibers, and hermetically coated fibers are discussed. The modified chemical vapor deposition and vapor phase axial deposition methods are described. Required properties of coating material and the cable structure and coating layer structure of fibers are detailed. High-speed coating technology and processability, the structural design of coating, and the mechanical properties of resin are discussed. The adhesive strength with glass and the environmental stability are discussed