可充碱性锌锰电池<英文>

七十年代初,可充碱锰电池在美国和芬兰就商品化了,由于MnO_2尚不能做到全放电,与铅酸和镍镉电池相比,缺乏竞争力。它主要用于便携式电视机和大型信号灯中,但没几年就停产了,此后又经历了以下几方面的改进:(1)控制锌阳极的容量,使MaO_2为第一电子放电,使锌近于完全溶解后再充电的问题减少,因锌几乎完全溶解后,电池再充性变差。控制阴极物质的组成,加入晶格稳定剂,使电池循环寿命延长。(2)阴极中添加适当的催化剂使电池中腐蚀氢再结合。采用第三电极氧循环,使电池增强过充电能力。(3)试验表明,高温时,其搁置寿命比镍镉、镍氢电池长。(4)降低电池中汞含量,有利于环境保护。(5)原材料及生产工艺进一步完善。最近,可充碱性锌锰电池的研制又取得了新进展。 1 薄阴极的特性 圆柱形电池中,MnO_2电极的厚度对电池的性能起决定性作用。图1(见正文——下同)表明阴极的厚度与MnO_2利用率的关系。适用于“D”(LR—20)、“C”(LR—14)、“AA”(LR—6)和“AAA”(LR—03)等电池。图中可看出,厚度越小,MnO_2利用率越高。对商品化的“D”型、“C”型、“AA”型及“AAA”型电池,其厚度分别为6mm、4mm、2mm、1mm。表1说明了不同型号的单体原电池的重量(g)与容量的关系。表2、表3则说明了单个原电池以及与之对应的电池组之间?

Research on Drug Loading Performance of Hydroxiapatite-Gelatin Composites by Co-precipication Method

Hydroxyapatite/polymer composites are promising materials for drug delivery applications.Studies focusing on the development of such composites are available in recent years,as using these materials as a carrier allows us to overcome the side effects of toxic drugs used especially in cancer treatments and increase treatment efficiency.In this study,hydroxyapatite-gelatin(HAp-GEL)composites are produced in the presence of simulated body fluid(SBF)as a carrier for 5-Fluorouracil(5-FU).Composites are produced by wet precipitation method at pH 7.4 and 37°C and crosslinked with glutaraldehyde(GA).In order to observe the effect of GA amount on drug loading efficiency,composites cross-linked with different amounts of GA are released in deinozed water,HCl and phosphate bufffer solution(PBS).Composites are analyzed by X-Ray Diffraction(XRD),Thermogravimetric Analyses(TGA),Scanning Electron Microscopy(SEM)and particle size distribution to observe morphology and structure.It is concluded that drug loaded HAp-GEL composites have a potential to be used in drug delivery applications.