9.2经验规律 Q热传导，Fourier'sLaw Jg Q/A=-KVT =1J4=27 ∂T 1 λ=k/cp Cp9.2 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