9.2 经验规律 Q热传导，Fourier'sLaw Jg Q/A=-KVT 肛= 1 at V.Jg=2T λ=k/cp Cp Q扩散，Fick'sLaw Jn n/A=-DVn on 8t =-7.Jm=D2n 9.2 经验规律 热传导，Fourier’s Law J𝑞 = 𝑄¤ /𝐴 = −𝜅∇𝑇 𝜕𝑇 𝜕𝑡 = 1 𝑐 𝑝 ∇ · J𝑞 = 𝜆∇ 2𝑇 𝜆 = 𝜅/𝑐 𝑝 扩散，Fick’s Law J𝑛 = 𝑛¤/𝐴 = −𝐷∇𝑛 𝜕𝑛 𝜕𝑡 = −∇ · J𝑛 = 𝐷∇ 2 𝑛 电流，Ohm’s Law J𝑒 = 𝜎E = −𝜎∇𝜙 𝜕𝑄 𝜕𝑡 = −∇ · J𝑒