On the electrochemical migration mechanism of tin in electronics

Electrochemical migration (ECM) of tin can result in the growth of a metal deposit with a dendritic structure from cathode to anode. In electronics, such growth can lead to short circuit of biased electrodes, potentially leading to intermittent or complete failure of an electronic device. In this paper, mechanistic aspects of ECM of tin are discussed in detail, using experimental results on ECM of tin in various environments and varying potential bias. Results on the formation of local pH changes by the electrodes and experiments observations are combined with thermodynamic stability of tin species as depicted in the Pourbaix diagram.     

全自动去离子水设备的研制

采用混床式离子交换树脂法生产去离子水，包括交换、自控、再生三个系统，每个系统用一个程序按钮实现去离子水设备的工况操作．交换柱采用透明的有机玻璃无缝管制成，便于观察，利于再生．电路部分都安装在一个金属柜内，以便集中控制．     

三乙醇胺对电火花线切割加工的影响

在去离子水中按比例逐步添加三乙醇胺[分子式为N(CH2CH2OH)3],在保证机床及其它工艺参数(机床、电极丝、试件和工艺参数)不变的前提下对试件进行切片实验,观察三乙醇胺浓度对加工效率及表面粗糙度的影响.实验证明,增加三乙醇胺的浓度,可以提高加工效率.     

论水性涂料中的水

水性涂料中的水不仅作为分散介质,而且对稀释助剂、清洗设备、计算固含量、颜基比、颜料体积浓度都有贡献,合理利用、分批添加去离子水,对做好水性涂料的生产工作很有裨益。     

Tapered plastic multimode fiber sensor for salinity detection

A simple tapered plastic multimode (PMM) fiber optic sensor is proposed and demonstrated for continuous monitoring of salinity based on different concentration of sodium chloride (NaCl) in de-ionized water. The working mechanism of such device is based on the observed increment in the transmission of the sensor that is immersed in sodium chloride solution of higher concentration which also reflects an increase in its refractive index. The tapered PMM fiber is fabricated using heat-pulling method to achieve a waist diameter and a length of 0.187 mm and 5 mm, respectively. As the solution concentration varies from 0% to 12%, the output voltage of the sensor increases linearly from 0.109 mV to 1.142 mV with a sensitivity of 0.0024 mV/% and a linearity of more than 98%. The main advantages of this sensor are the feasibility of using PMM fiber which makes the sensor tougher, easier to fabricate and handle.