The color reaction conditions of Cu 2+ and 1-(2-pyridylazo)-2-naphthol(PAN)were researched, and a new method was developed for the determination of copper in sulfuric acid anodizing liquor.

研究了铜与1-（2-吡啶偶氮）-2-萘酚（PAN）的显色反应，建立了测定硫酸阳极氧化液中铜的新方法。

youdao

PAN on the samples has symmetrical color, high substance, exquisite particles and good thermal stability.

所得样品上的聚苯胺颜色均匀，牢度高，粒度细腻，热稳定性好。

youdao

Here, jade Guanyin static bottles of holy water, talking to the Castle Peak Emerald moist ravines, pan-green water color.

这里的观音玉静瓶之圣水，讲沟壑滋润使青山叠翠，绿水泛彩。

youdao

When the caramel is the color you want, remove the pan from the heat and cool the mixture.

NPR: Cookbook Author Celebrates Apple Season

For the first 15 minutes or so, you want the onions at the bottom of the pan to be slowly but steadily taking on color as they sweat out their liquid.

WSJ: Momofuku Recipes by David Chang