自聚物裂解工艺制备5V正极材料LiNi_(0.5)Mn_(1.5)O_4

采用溶胶凝胶法的新型自聚物裂解工艺合成5 V锂离子电池LiNi_(0.5)Mn_(1.5)O_4正极材料,经XRD、SEM和充放电循环测试,合成材料具有尖晶石结构,粒径大小分布均匀,在0.2 C充放电下首次放电比容量达到141 mAh/g,循环100次容量保持率为93%,与其它溶胶凝胶法的柠檬酸乙二醇工艺和高分子PAA工艺合成材料相比,电化学性能良好。     

水涂粉材料及工艺

水涂粉材料及工艺艾海（天津照明电器工业公司天津市３００１１２）１前言水涂粉工艺是以水作为溶剂（对粘着剂而言）和分散介质（对荧光粉而言）配制荧光粉悬浮液（简称粉浆）涂敷荧光粉层的工艺。荧光灯水涂粉新工艺，从根本上克服了传统的有机溶剂涂粉工艺的上述缺点，...     

环氧树脂粉末涂料技术

环氧树脂粉末涂料技术吴玉霞（南京微分电机厂）１概述环氧树脂粉末涂料是一种不含有机溶剂的干态固体粉末，它与一般溶剂型的涂料和水性涂料不同，涂装时不需要用溶剂或水作为分散介质，而是以空气作为分散介质，均匀地涂装于工件表面，加热后形成涂膜的一种新型涂料，这...     

Tween—80和SDBS对纳米TiO2在水溶液中分散稳定性的影响

探讨了纳米二氧化钛颗粒的液相分散工艺，研究结果表明，以水作为分散介质，通过加入适当的表面活性剂，以及调节pH值可以制备出高分散、高稳定的纳米颗悬浮液，此法可获得较理想的分散效果。     

Vilsmeier法合成3，4-二甲氧基苯甲醛的研究

以邻苯二酚为原料，经醚化和Vilsmeier反应，两步合成了3，4-二甲氧基苯甲醛，总收率达83．6％并对两步反应的工艺条件进行了优化．     

酚醛改性二苯醚衍生物树脂的研制及其应用

本文分析了酚醛改性二苯醚衍生物树脂的合成反应机理。通过实验，探索出其合成反应的最佳配方和工艺参数，在对该树脂作了热老化分析的基础上，成功地应用在H级层压板上。     

酚醛改性二苯醚衍生物树脂的研制及其应用

本文分析了酚醛改性二苯醚衍生物树脂的合成反应机理。通过实验，探索出其合成反应的最佳配方和工艺参数，在对该树脂作了热老化分析的基础上，成功地应用在Ｈ级层压板上。     

混合型粉末涂料专用聚酯树脂的合成

研究混合型粉末涂料专用聚酯树脂合成的技术条件，结果表明，合理的醇酸当量比和控制反应程度及工艺条件是制备高分子量聚酯树脂的关键技术。     

混合型粉末涂料专用聚酯树脂的合成

研究混合型粉末涂料专用聚酯树脂合成的技术条件，结果表明，合理的醇酸当量比和控制反应程度及工艺条件是制备高分子量聚酯树脂的关键技术。     

含磷环氧树脂及其在无卤化覆铜板中的应用

本文综述了日本在含磷环氧树脂的研究进展，包括环状有机磷化合物的结构、合成、与环氧树脂反应的机理、含磷环氧树脂合成工艺、阻燃性能以及在无卤化阻燃FR-4覆铜板中的应用。     

LED RGB投光灯中的色散分析及其优化设计

根据光在均匀介质中的折射原理,从理论上分析了LED灯具透镜引起色散的原因。针对因折射而产生的色散现象,提出了降低色散影响的若干措施,并以RGB投光灯为例,设计了一个带微透镜阵列的全内反射透镜。模拟和实验结果表明,该透镜能对R、G、B三种光线实现较为一致的发光角度和光强分布。     

中压配电网无功补偿装置对PLC信道特性的影响分析

分析中压配电网无功补偿装置对PLC信道特性影响规律,为实现PLC在中压配电网中的应用提供必要的理论基础和参考依据。通过对中压配电网现有无功补偿方式及常见补偿装置的分析,指明经配电变压器接入中压配电网的低压集中补偿和用户终端分散补偿的无功装置对中压侧PLC信道特性影响可忽略不计。故在中压配电网PLC信道模型基础上,重点分析变电站集中补偿和杆上无功分散补偿两种方式下,无功补偿装置的数量、补偿容量、补偿位置等因素对载波信号的传输特性和输入阻抗的影响规律。研究结果表明:若无功补偿装置直接接入补偿点,则电压衰减的幅度随着补偿容量、补偿点数量的增加而增大,与补偿位置基本无关;若无功补偿装置经一定长度的电缆接入补偿点,则以上各因素对电压衰落的影响可忽略不计。     

Dispersion and Optical Activities of Copper (II) Metal Oxide Nanoparticles with Polyethylene Glycol in Aqueous Medium Studied with Physicochemical Properties and UV-Vis Spectrophotometry

Abstract

Copper (II) oxide nanoparticles are considered to be transition metal oxide having unique properties and could be useful in biochemical and biomedical applications. The hydrophilic biocompatible polyethylene glycols (PEG) were used for dispersion of CuO in aqueous medium. The physicochemical properties (PCPs) and absorbance were determined for CuO dispersed. The PCPs and optical data showed a maximum CuO dispersion with water and PEG which revealed that the impact of the hydrophobic chain and hydrophilic [sbond]OH groups in PEG on dispersion activities The results can provide new insights in the development of dispersion activities of CuO with PEG _{(400 and 6000).}     

10-80-Gb/s highly extinctive electrooptic pulse pattern generation

A pulse-rate-tunable, highly extinctive, ultra-highspeed electrooptic pulse pattern generator has been developed. The optical short pulse generation is based on sinusoidal electrooptic phase modulation and linear chirp compensation using a dispersive medium. Filtering the nonlinear chirp components generated by sinusoidal phase modulation drastically improves the pulse extinction, and makes nearly background-free picosecond pulsation over a wide pulse-rate range even when the group delay dispersion value is fixed     

Inversion response to optimize lumped‐element circuits for metamaterial

Enhancing electromagnetic research on prior light bend mechanisms is a significant issue for composite material phenomena, and one that is not available in nature. The unit cell of metamaterial can be revised, such that it is significantly smaller than the free space of the wavelength. It is essential to extend the appropriate retrieval process to measure electrical and magnetic responses to the backward wave propagation and dispersion diagram characteristics. In this paper, we propose a retrieval process inversion response between known and unknown parameters of the lumped unit‐cell circuits that optimizes the best fit parameters. By utilizing the optimization of particle swarm techniques, we provide appropriate values of periodic unit cells of CRLH transmission line circuits that matched with the microstrip implementation model. The group velocity of the wave is indicated in the parallel direction, whereas the phase velocity is in the anti‐parallel direction. The dispersion diagram displayed a specifically left‐handed and right‐handed medium, and a tiny band gap appeared in the attenuation medium. The constitutive parameters of dielectric permittivity, permeability, and refractive index were obtained from the periodic composite transmission line circuits.     

塑料光纤中的随机微扰效应

将塑料光纤 ( POF)作为某些短距离应用的高宽带的光纤连接线 ,因为其延展性好 ,芯径大 ( 1 mm )。与玻璃光纤相似 ,多模塑料光纤的带宽也受模间色散的限制。这可用抛物线型渐变折射率分布 ( GI)的塑料光纤予以改进。本文用另一种方法来解决色散问题 ,以祈改进塑料光纤的带宽。最近研究表明 ,由于随机折射率微扰和模耦合 ,使带宽出乎意料地大大展宽 ,这就是本文的主题     

全尺寸直流电缆脉冲电声法（PEA）空间电荷测量系统设计及声信号衰减与色散补偿

脉冲电声法（PEA）空间电荷测量是交联聚乙烯（XLPE）绝缘直流电缆材料选型与评价的主要技术手段,被广泛应用于直流电缆薄膜试样。但应用该方法测量厚尺寸平板试样和大尺寸同轴试样以研究材料体效应对空间电荷的影响时,声波信号在材料中传播时的衰减与色散将直接影响电荷密度测量的精度和空间分辨率。提出了在空间电荷校准过程中利用理论计算直流电场的方法确定内外电极表面的电容电荷密度,然后计算确定在绝缘介质中传播的脉冲声波信号传递函数（该函数含有衰减和色散系数）,再对原始信号进行反卷积分运算以去除系统响应。在频域利用测量信号乘以传递函数获得脉冲声波信号经过衰减、色散恢复后的信号,从而保证大尺寸直流电缆试样测量中电荷密度及空间分辨率的测量精度。同时,设计了全尺寸直流电缆空间电荷测量系统,并在LabVIEW环境下开发了数据采集与处理系统。     

Study on dispersion property of sub-micro α-Al2O3 powders in water suspension by physical-chemical process

ABSTRACT

Sub-micro α-Al₂O₃ polishing liquid is often used as the slurry in chemical mechanical polishing (CMP). At present, water is usually used as dispersion medium to disperse sub-micro α-Al₂O₃ powders, but the sub-micro α-Al₂O₃ powders easily subside in aqueous solution. In previous studies, researchers usually used single method to disperse superfine powders, however, the dispersion effect was non-ideal. In order to solve the difficult problem of sub-micro α-Al₂O₃ powders dispersed in water suspension, firstly, using physical method, the effects of milling time, ultrasonic time on the dispersion property of sub-micro α-Al₂O₃ powders in water suspension was studied by single factorial test. Then, using chemical method, the effects of dispersant type, dispersant concentration and pH value on the dispersion property of sub-micro α-Al₂O₃ powders in water suspension was studied by orthogonal test. Absorbance was used to evaluate the dispersion property of sub-micro α-Al₂O₃ powders. The results show that the optimal dispersing conditions are milling time 60 min, ultrasonic time 20 min, mass percent concentration of STPP 1% and pH value 9.     

电磁波斜入射分层介质问题FDTD分析

分层半空间二维斜入射问题一般转化为一维情况来处理,但该处理方法的有效性与入射角的大小紧密相关。对一维修正处理方法斜入射角度的适用范围进行了研究,同时,利用该方法研究了介质的介电常数、电导率和色散特性对反射波时域、频域特性的影响,结论对分层半空间问题FDTD分析、地物反演等应用有重要指导作用。     

Research into the Electrokinetic Properties of Electrographic Liquid Developers

A well-known method based on electrophoretic measurements was applied to evaluating the main parameters of liquid electrographic developers, that is, electrokinetic characteristics (e.g., mobilities, charge, and ￠ potential of particles), as well as the size and numerical concentration of particles. The generalization of this method for polydisperse systems is dealt with, taking into account the possible dispersion of the charges of particles. This allows evaluation of an error in determining the mean values of parameters and sets the limits of applicability of the method. A modification of the calculation is suggested, which would allow the mean concentration of particles to be determined. For a number of systems employed in practice it is shown that the electrokinetic properties of liquid electrographic developers depend on the nature of pigments and their chemical modification (e.g., by the aid of surfactants), and on the parameters of a binder and a dispersion medium. A number of relations are derived from the research work done, which allow the optimum choice of the parameters of liquid electrographic developers to be made.