An inter-laboratory comparison study for the determination of copper and lead from the wastewater of printed circuit board manufacturing industry in Pakistan

This inter-laboratory comparison study was arranged for 28 laboratories from different public and private sector organizations in Pakistan having wastewater testing capabilities aimed at improving the quality and comparability of test results. This national inter-laboratory study was started in December 2003 and completed in July 2004. Laboratories were invited to analyze the wastewater collected from printed circuit board (PCB) industry for lead and copper contamination. The samples fulfill the criteria for homogeneity and stability as done by the reference laboratory. The results obtained from participating laboratories were analyzed in terms of Hampel Test for outliers, while the performance evaluation of the participating laboratories was done on the basis of Z-score. An assigned value derived from the participant's results was compared with a reference value provided by a reference laboratory. Overall >50% of the participating laboratories have shown good performance in this PT-program     

聚硅氧烷聚脲嵌段共聚物的TEM及SAXS研究

采用透射电子显微镜与小角X光散射分别研究了不同软、硬段分子量及软段极性对聚硅氧烷聚脲多嵌段共聚体系微相结构的影响。结果表明,增加软段分子量及硬段含量有利于聚硅氧烷与聚脲的相分离。将极性氰丙基引入聚硅氧烷后两相混合度明显改善,同时聚脲硬段粒径减小并趋于均一。在聚氰丙基甲基硅氧烷基体中增加聚脲含量及其分子量,则两相界面厚度也随之增大。     

高活性、高产率非线性偶氮化合物的合成及其线性、非线性光学性能

合成了一类高产率的基于偶氮的新型非线性活性化合物. 初步测定其薄膜的折射率可在1.55—1.64范围内任意调节, 薄膜的Tg在130 ℃ 以上, 其未经优化的非线性光学系数γ33为16 pm/V(1310 nm), 该材料在通讯波长窗口的光学损耗较小, 化合物的热分解温度在239 ℃ 以上.     

氮气退火对二氧化钛薄膜光学性能的影响

 提出了一种利用离子注入和后续退火制备氮掺杂TiO₂薄膜的方法。首先在室温下向石英玻璃中注入Ti离子,随后在氮气中退火到900 ℃,从而制备了氮掺杂的玻璃基TiO₂薄膜。SRIM2006程序模拟和卢瑟福背散射谱（RBS）研究表明注入离子从样品表面开始呈高斯分布,实验结果和模拟结果吻合很好。X射线光电子能谱（XPS）研究结果表明注入态样品中形成了金属Ti和TiO₂,900 ℃退火后金属Ti转变成TiO₂,同时N原子替代少量的晶格O原子形成了O－Ti－N化合物。紫外-可见吸收光谱（UV-Vis）结果显示,当退火温度至500 ℃时,在吸收光谱中开始出现TiO₂的吸收边,随退火温度升高到900 ℃,由于O－Ti－N化合物形成,TiO₂的吸收边从3.98 eV红移到3.30 eV,TiO₂吸收边末端延伸到可见光区,在可见光区的吸收强度明显增加。     

First-principles study of He point-defects in HCP rare-earth metals

He defect properties in Sc, Y, Gd, Tb, Dy, Ho, Er and Lu were studied using first-principles calculations based on density functional theory. The results indicate that the formation energy of an interstitial He atom is smaller than that of a substitutional He atom in all hcp rare-earth metals considered. Furthermore, the tetrahedral interstitial position is more favorable than an octahedral position for He defects. The results are compared with those from bcc and fcc metals.     

310 ℃和350 ℃下锆-4合金中沉淀相非晶化研究

用大束流加速器和透射电子显微镜研究了Zr-4合金在310 ℃和350 ℃下的质子辐照效应。当质子能量为2 MeV，在310 ℃和350 ℃下质子辐照产生原子离位损伤达5 dpa（注量率为8.5×1013 cm-2·s-1），辐照前后的明场像、高分辨相和电子衍射花样均表明:在310 ℃辐照产生原子损伤达到5 dpa，沉淀相Zr(Cr,Fe)2边缘5～10 nm的区域已经非晶化，而在350 ℃时质子辐照却没有非晶化发生。沉淀相Zr(Cr,Fe)2的元素分布图像和浓度分布表明，铁元素向基体扩散并且聚集在非晶化边界区域。     

Some Properties of Chromatic Coefficients of Linear Uniform Hypergraphs

In this paper a formula for the coefficient of λ ^n-gh+g-1 in the chromatic polynomial of a linear h-uniform hypergraph H of order n and girth g is proposed provided (g,  h) ≠ (3, 3). This formula involves 13 types of spanning subhypergraphs of H for 3 ≤ h ≤ 5.     

离子注入金红石单晶生成的金属Ni纳米晶的磁学性能研究

 研究了能量为64keV、注量1×10¹⁷cm^-2的Ni离子注入金红石TiO₂单晶制备的植入金属纳米晶的微观结构和磁学性能。注入层的结构和磁学性能采用透射电子显微分析（TEM）和超导量子干涉磁强计（SQUID）进行分析。结果表明，金红石单晶中有尺寸为3～18nm的金属Ni纳米晶生成，注入区域基体明显非晶化。10K温度下金属Ni纳米晶的矫顽力约为16.8kA·m^-1，比Ni块材的矫顽力大。样品的零场冷却/有场冷却（ZFC/FC）曲线表明，金属Ni纳米晶的截止温度约为85K。     

高分辨光谱的计算机自动读谱及辅助分析

本文以谱线中心位置在整个谱型中所独有的特性和噪声阈值为依据,提出了一种计算机自动获取谱线中心频率及其相对强度的简便算法,并设计了相应的计算机程序。将该方法和程序应用到具有代表性的由十多条CHF3谱线部分重迭组成的可调远红外实验谱图的预分析,结果表明所获取的谱线中心频率和相对强度与人工获取这些参数初值后经拟合得到的准确结果非常一致,验证了该方法和程序的准确性和有效性,表明其有着广泛的应用前景,可作为处理日益骤增的光谱信息的强有力工具。