△U=一·B=L·B 2m 如B在Z方向 e △m如n,B= PBMLB μB=9.27310-24如 在 方向 Lˆ B 2 m e U B e Δ = − L ⋅ = ⋅ r μ B z L BL e U mB mB 2m Δ = =μ h 9.273 10 J T 24 B − μ = ⋅