所以按wikipedia的说法,本生灯不开氧气门的时候会产生很小的碳粒,它的热辐射( 白炽发光)产生黄光。 氧气打开之后,产生的碳粒非常少,剧烈的氧化反应产生大量被激发的自由基(主要是 CH),发射蓝光。 http://en.wikipedia.org/wiki/Flame#Flame_color In a laboratory under normal gravity conditions and with a closed oxygen valve, a Bunsen burner burns with yellow flame (also called a safety flame) at around 1,000 °C (1,800 °F). This is due to incandescence of very fine soot particles that are produced in the flame. With increasing oxygen supply , less black body-radiating soot is produced due to a more complete combustion and the reaction creates enough energy to excite and ionize gas molecules in the flame, leading to a blue appearance. 下面这个图是丁烷火焰的光谱,其中CH是次甲基自由基的发射带,C2是二碳自由基的发 射带。 Spectrum of the blue (premixed, i.e., complete combustion) flame from a butane torch showing molecular radical band emission and Swan bands. Note that virtually all the light produced is in the blue to green region of the spectrum below about 565 nanometers, accounting for the bluish color of sootless hydrocarbon flames. 打火石的火花和本生灯的火焰,分别是热辐射和分子受激发光的结果: 其中打火石的火花是高温的打火石颗粒的黑体(白炽)辐射,其亮白-橙-红的颜色转化 是火石颗粒温度降低的结果。蓝色的丁烷火苗不是黑体辐射,而是主要来自于次甲基( CH)自由基的受激发光。 The incandescent metal embers of the spark used to light this Bunsen burner emit light ranging in color from white to orange to red or to blue. This change correlates with their temperature as they cool in the air. The flame itself is not incandescent, as its blue color comes from the quantized transitions that result from the oxidation of CH radicals.