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T=5800;​​λmin=50*10^(-9);​​λmax=3000*10^(-9);​​L=(2*h*c^2)/(λ^5)*1/(Exp[(h*c)/(k*λ*T)]-1);​​Lir=Piecewise[{{0,0<λ<780*10^(-9)},{L,780*10^(-9)<λ<3000*10^(-9)}}];​​Lsichtbar=Piecewise[{{0,0<λ<380*10^(-9)},{L,380*10^(-9)<λ<780*10^(-9)}},{0,780*10^(-9)<λ<3000*10^(-9)}];​​Lsichtbar=Piecewise[{{0,0<λ<380*10^(-9)},{L,380*10^(-9)<λ<780*10^(-9)}},{0,780*10^(-9)<λ<3000*10^(-9)}];​​Luv=Piecewise[{{0,0<λ<100*10^(-9)},{L,100*10^(-9)<λ<380*10^(-9)},{0,380*10^(-9)<λ<3000*10^(-9)}}];​​h=6.626*10^(-34);​​c=2.998*10^8;​​k=1.381*10^(-23);​​kurve1=Plot[L,{λ,λmin,λmax},AxesLabel{"λ in m","L in J/(m^3*s)"},PlotRangeAll]​​kurveir=Plot[Lir,{λ,λmin,λmax},AxesLabel{"λ in m","L in J/(m^3*s)"},PlotRangeAll,FillingAxis,FillingStyleRed,PlotLegendsSwatchLegend[{Red,Green,Blue},{"Infrarot","Sichtbar","Ultraviolett"}]];​​kurvesichtbar=Plot[Lsichtbar,{λ,λmin,λmax},AxesLabel{"λ in m","L in J/(m^3*s)"},PlotRangeAll,FillingAxis,FillingStyleGreen];​​kurveuv=Plot[Luv,{λ,λmin,λmax},AxesLabel{"λ in m","L in J/(m^3*s)"},PlotRangeAll,FillingAxis,FillingStyleBlue];​​Show[kurve1,kurveir,kurvesichtbar,kurveuv]​​
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Infrarot
Sichtbar
Ultraviolett