| 查看: 435 | 回复: 3 | |||
| 当前主题已经存档。 | |||
sxy5306铁杆木虫 (著名写手)
|
[交流]
【讨论】概念辨析！！
|
||
| Fluorescence，luminescence，photoluminescence的主要区别是什么？ |
回复此楼» 猜你喜欢
越来越担心硕士毕业后没有竞争力了
已经有14人回复
-
论文的挂名怎么评判贡献？基金申请中，排名第一的挂名文章
已经有3人回复
-
申博自荐 2篇一区TOP+1篇EI+2公开发明专利 2027博士申请
已经有3人回复
-
闲聊
已经有6人回复
-
申博求助
已经有4人回复
wenyun0876
木虫 (正式写手)
老木虫
- 应助: 6 (幼儿园)
- 贵宾: 0.01
- 金币: 9096.4
- 散金: 28
- 红花: 1
- 帖子: 841
- 在线: 344.2小时
- 虫号: 494388
- 注册: 2008-01-13
- 专业: 无机非金属类光电信息与功
2楼2009-10-09 07:57:53
yjyang07
木虫 (著名写手)
- 应助: 0 (幼儿园)
- 金币: 2144.6
- 散金: 200
- 红花: 5
- 帖子: 1205
- 在线: 109.6小时
- 虫号: 821620
- 注册: 2009-08-04
- 性别: GG
- 专业: 凝聚态物性 II ：电子结构
3楼2009-10-09 08:19:25
★ ★
hitechceram(金币+2,VIP+0): 10-12 11:44
hitechceram(金币+2,VIP+0): 10-12 11:44
|
Fluorescence is the emission of visible light by a substance that has absorbed light of a differing, usually invisible, wavelength. Absorption of a photon triggers the emission of a photon with a longer (less energetic) wavelength. A shorter wavelength emission is sometimes observed from multiple photon absorption. The energy difference between the absorbed and emitted photons ends up as molecular rotations, vibrations or heat. Sometimes the absorbed photon is in the ultraviolet range, and the emitted light is in the visible range, but this depends on the characteristics of the particular fluorescent substance. Luminescence is light that usually occurs at low temperatures, and is thus a form of cold body radiation. It can be caused by chemical reactions, electrical energy, subatomic motions, or stress on a crystal. This distinguishes luminescence from incandescence, which is light generated by high temperatures. Historically, radioactivity was thought of as a form of "radioluminescence", although it is today considered to be separate since it involves more than electromagnetic radiation. Photoluminescence (abbreviated as PL) is a process in which a substance absorbs photons (electromagnetic radiation) and then re-radiates photons. Quantum mechanically, this can be described as an excitation to a higher energy state and then a return to a lower energy state accompanied by the emission of a photon. This is one of many forms of luminescence (light emission) and is distinguished by photoexcitation (excitation by photons), hence the prefix photo-.[1] The period between absorption and emission is typically extremely short, in the order of 10 nanoseconds. Under special circumstances, however, this period can be extended into minutes or hours. |
4楼2009-10-12 11:08:12