Electroplating of Ni-Cr on steel with pulse plating

It has been difficult to electrolytically obtain crack- free chromium plating because of the high stresses caused by several factors. Accordingly, electroplating of nickel- chromium also encounters a similar problem. Cracks in chromium- containing plating was ascribed, in a certain sense, to the formation of a hydride formed through hydrogen adsorption from the electrolyte. A periodical pulse reverse plating current would enhance the release of hydrogen and hence the elimination of cracking. The present work describes a successful process for obtaining crack- free nickel- chromium plating and the effects of experimental variables on plating compositions.     

Electrolyte effects on oxygen reduction kinetics at platinum: A rotating ring-disc electrode analysis

A comparative study of the electrode kinetics of oxygen reduction of platinum in perchloric, phosphoric, sulfuric, trifluoromethanesulfonic acids (all at pH = 0) and in potassium hydroxide (pH = 14) was made at 25°C using rotatating ring-disc electrode techniques. The platinum electrode was first characterised in these electrolytes using the cyclic voltammetric method. The results showed that in the potential region from 0.8 to 0.6 V/rhe, the kinetics of oxygen reduction in these electrolytes decreases in the order KOH > H₂SO₄ ～ CF₃SO₃H > H₃PO₄ > HClO₄. This order of activity is reflected in the effects of the electrolytes, in respect to specific adsorption of anions, on the platinum oxide formation reaction. The role of anion adsorption is also apparent in the dependence of the rate constant for oxygen reduction to water or to hydrogen peroxide and of hydrogen peroxide reduction to water on potential. The superior behavior of oxygen reduction in KOH is due to minimal adsorption of the OH^? ion. The more complex adsorption behavior of the oxyanions in the investigated acid electrolytes than that of simple anions like the halide ions presents difficulties in drawing detailed correlations between oxygen reduction kinetics and adsorption behavior of oxyanions of platinum.     

大气奈米微粒与前驱气体关连性研究

本研究以MOUDI与Nano-MOUDI组合系统采集并分径大气奈米微粒,于设计流量下可分为10～18,18～32,32～56,56～100 nm等范围.采样后滤纸以6位数电子天平及离子层析仪(Ion Chromatography,IC)分析重量浓度及无机盐类成份,包含Cl-,SO42-,NO3-,NH4+,Na+,K+,Mg2+,Ca2+等离子组成特性.结果显示,潮州地区大气奈米微粒重量浓度浓度为1.29～4.62μg/m3,与PM1,PM2 5,PM10之比值为3.0%～8.3%,2.2%～6.1%,1.7%～4.9%大寮地区大气奈米微粒重量浓度浓度为1.17～3.15 μg/m3,与PM1,PM2.5,PM10之比值为2.9%～8.5%,2.1%～6.1%,1.5%～4.2%,大气奈米微粒重量浓度与PM1,PM2.s,PM10重量浓度间不具相关性,即PM污染事件发生时,奈米微粒浓度并不会上升.化学分析结果,大气奈米微粒无机盐类组成中,SO42-含量最高,占约8.0%、其次为NH4+(5.4%),NO3-(3.9%),Na+,K+,Mg2+,Ca2+,Cl-等总和占约4.6%,而未分析之成份则占78.1%,其中SO42-,NH4+,NO3-易受环境因素而改变含量,而其总含量随奈米微粒重量浓度增加而减少,显示奈米微粒受未分析成份影响较大.     

制作在不锈钢薄膜衬底上的柔性电子图书显示器

2005年10月,LG.PhilipsLCD和EInk公司联合推出了一款10.1in的SVGA反射式柔性有源矩阵光电显示器,该显示器成功地制作在一个薄薄的不锈钢薄膜衬底上。该产品原型在外观上和手感上与真实的纸张极为相似,非常薄且轻,并且具有宽视角和高对比度。     

Single-walled carbon nanotubes as excitonic optical wires

Although metallic nanostructures are useful for nanoscale optics, all of their key optical properties are determined by their geometry. This makes it difficult to adjust these properties independently, and can restrict applications. Here we use the absolute intensity of Rayleigh scattering to show that single-walled carbon nanotubes can form ideal optical wires. The spatial distribution of the radiation scattered by the nanotubes is determined by their shape, but the intensity and spectrum of the scattered radiation are determined by exciton dynamics, quantum-dot-like optical resonances and other intrinsic properties. Moreover, the nanotubes display a uniform peak optical conductivity of approximately 8 e(2)/h, which we derive using an exciton model, suggesting universal behaviour similar to that observed in nanotube conductance. We further demonstrate a radiative coupling between two distant nanotubes, with potential applications in metamaterials and optical antennas.