109 visible spectral region 入maxT=2898以m-K Solar radiation 10 5800K 2000K 104 1000K 800K 10 300K 100K 102 10-3 50K 104 0.1 0.2 0.40.6 1 2 46 10 20 4060100 Wavelength,入(um) FIGURE 12.13 Spectral blackbody emissive power. Plank distribution curve Plank distribution curve