1. City Light Color, Why Yellow
- Older installation use sodium vapor lamps, emit yellow orange light
- Visibility and comfort
- Transition to LED, origin cold, now can produce warmer hues
1.1. How Sodium Vapor Lamps Works
Components
- Bulb
- Contain small amount sodium
- Inert gas (usually neon or argon)
How:
- Starting, the inert gas ionized, easier at lower temperature
- Heating sodium, vaporize the sodium
- Sodium ionization, emit light efficiently
2. Jade Culture
种类，化学组成，形成方式，欣赏
种类：
- 硬玉，比如翡翠，硅酸铝钠，硬度6.5-7.0
- 颜色多样，从翠绿到白色、黄色、黑色。包含的微量元素和杂志决定了颜色变化
- 绿色：铬，越高越鲜艳
- 紫色：铁，三价铁
- 红色：微量铁
- 黄色：铁和锰
- 黑色、深灰色：铁的氧化物
- 形成：与变质岩和热液活动有关，多产于缅甸、中美洲
- 颜色多样，从翠绿到白色、黄色、黑色。包含的微量元素和杂志决定了颜色变化
- 软玉：和田玉，长石族-透闪石，硬度6.0-6.5
- 颜色较为单一，通常为乳白色，偶尔带有绿色或者黄色
- 形成：与沉积岩有关，多产于新疆地区
欣赏
- 冰种玉：透明度高、纹理细腻的翡翠，价值较高
- 玻璃种：冰种玉的一种，透明度极高，几乎没有杂志
- 糯冰种：透明度较好
3. How Roaming Works
Meaning: continued use of mobile phone and cellular while outside coverage of home network
How it works
- Network partnership
- Connecting to local network
- Data transfer
- Billing