ElementData["Silver","ThermalConductivity"]

ElementData["Copper","ThermalConductivity"]

Needs["VectorAnalysis`"]

SetCoordinates[Cartesian[x,y,z]];

Div[λ*Grad[T[x]]]

teplota=T[x]/.DSolve[{T''[x]==0,T[0]==T1,T[d]==T2},T[x],x][[1]];

qvektor=-λ*Grad[teplota]