Barrier layer effect of tantalum on the electromigration in sputtered copper films on hydrogen silsesguioxane and SiO2

As IC devices scale down to the submicron level, the resistance-capacitance (RC) time delays are the limitation to circuit speed. A solution is to use low dielectric constant materials and low resistivity materials. In this work, the influence of underlying barrier Ta on the electromigration (EM) of Cu on hydrogen silsesquioxane (HSQ) and SiO₂ substrates was investigated. The presence of a Ta barrier not only improves the adhesion between Cu and dielectrics, but also enhances the crystallinity of Cu film and improves the Cu electromigration resistance. The activation energy obtained suggests a grain boundary migration mechanism and the current exponent calculated indicates the Joule heating effect.     

以不同PAN系炭纤维布制备燃料电池气体扩散层之研究

采用石墨化PAN系炭纤维布制备了高分子电解质燃料电池气体扩散层。通过电学实验、X-ray绕射与元素分析考察了所制气体扩散层的性能。结果表明：随热处理温度的升高，气体扩散层的电阻率降低，L2增加，d（x）2减小。高温处理后的炭纤维布作为高分子电解质燃料电池气体扩散层显示了较高的电池效能。     

Non-linear current–voltage characteristics related to native defects in SrTiO3 and ZnO bicrystals

SrTiO₃ and ZnO bicrystals with various types of boundaries were fabricated in order to examine their current–voltage characteristics across single grain boundaries. Their grain boundary structures were also investigated by high-resolution transmission electron microscopy. In Nb-doped SrTiO₃, electron transport behaviors depend on the type of boundaries. Random type boundaries exhibit highly non-linear current–voltage characteristics, while low angle boundaries show a slight non-linearity. On the contrary, undoped ZnO does not exhibit non-linear current–voltage characteristics in any type of boundaries including random ones. It is suggested that the differences observed in current–voltage properties between the two systems are mainly due to the difference in the accumulation behavior of acceptor-like native defects at grain boundaries. A clear non-linearity is obtained by means of Co-doping even for the highly coherent Σ1 boundary in a ZnO bicrystal. This is considered to result from the production of acceptor-like native defects by Co-doping.     

Thermal Conductivity Measurement of an Electron-Beam Physical-Vapor-Deposition Coating

An industrial ceramic thermal-barrier coating designated PWA 266, processed by electron-beam physical-vapor deposition, was measured using a steady-state thermal conductivity technique. The thermal conductivity of the mass fraction 7 % yttria-stabilized zirconia coating was measured from 100 °C to 900 °C. Measurements on three thicknesses of coatings, 170 μm, 350 μm, and 510 μm resulted in thermal conductivity in the range from 1.5 W/(m·K) to 1.7 W/(m·K) with a combined relative standard uncertainty of 20 %. The thermal conductivity is not significantly dependent on temperature.     

聚酰亚胺渗透汽化膜的研究(Ⅰ)膜的制备和结构对动态吸附特性的影响

以2种二酐，3种二胺为单体，两步法制备了6种不同结构的聚酰亚胺均质膜，通过红外光谱和元素分析证实了其重复单元的分子结构，测定了这几种膜的物理性质和对水蒸气的动态吸附性能，并计算出其反常扩散指数dw。实验表明，随着聚合物二胺单元分子结构的变化，按MDA、ODA、PDA的顺序，密度逐渐变大，链间距逐渐减小，链堆砌变得紧密，水蒸气在膜中的吸附和扩散也变慢，并出现从正常扩散到反常扩散的过渡现象。     

离心式高炉鼓风机扩压叶片断裂事故分析及处理

通过高炉鼓风机扩压叶片断裂事故，从化学分析、物理检验，结合使用情况对扩压叶片断裂原因进行了详细分析，并提出了改进措施。     

Al-Cu双金属复合结构的扩散连接试验研究

应用扩散连方法进行了Al-Cu双金属复合结构的试验研究，比较了不同的焊接工艺，材料组合以及母材状态情况Al合金与Cu的连接性，观察了接头区域的微观组织结构，研究表明，固相扩散连接是一种适用于异种材料连接的有效方法，通过在连接区域形成Al-Cu金属间化合物，达到Al和Cu的有效连接，材料组合，母材原始状态以及连接工艺参数对Al合金与Cu的扩散连接存在着明显的影响。表面镀Ni工艺不但能够有效阻止Al和Cu之间形成脆性相，而且Al和Ni之间形成了良好的扩散连接，改善了接头性能。     

Copper(II) removal from aqueous solutions by fly ash

The removal of Cu(II) by adsorption on fly ash has been found to be concentration, pH and temperature dependent. The kinetics of adsorption indicates the process to be diffusion controlled. The Langmuir constants have been calculated at different temperatures, and the adsorption has been found to be endothermic (ΔH = 15.652 kcal mol^?1). The maximum removal is observed at pH 8.0, and variation in adsorption with pH has been explained on the basis of surface ionisation and complexation.     

EXPERIMENTAL INVESTIGATIONS ON LONGITUDINAL DISPERSION CHARACTERISTICS OF TIDAL RIVERS

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＵｎｄｅｒｔｈｅｉｎｆｌｕｅｎｃｅｏｆｎａｔｕｒａｌｔｉｄｅｓ,ｔｈｅｉｎｔｅｒａｃ ｔｉｏｎｓｂｅｔｗｅｅｎｆｌｏｗｆｅａｔｕｒｅｓａｎｄｐｏｌｌｕｔａｎｔｌｏｎｇｉｔｕｄｉｎａｌｄｉｆｆｕｓｉｏｎｉｎｔｉｄａｌｒｉｖｅｒｓａｒｅｉｍｐｏｒｔａｎｔｆｏｒｗａｔｅｒｅｎｖｉ ｒｏｎｍｅｎｔｒｅｃｔｉｆｉｃａｔｉｏｎｉｎｅｓｔｕａｒｉｎｅｒｅｇｉｏｎｓ.Ｔｈｅｄｉｆｆｕ ｓｉｏｎａｎｄｔｒａｎｓｐｏｒｔｏｆｐｏｌｌｕｔａｎｔｉｎｎａｔｕｒａｌｒｉｖｅｒｓｆａｌｌｉｎ ｔｏｍ…