The model is based on the characteristics of BEC at finite temperature from the view of free energy variance of the canonical system.

• 摘要从平均场理论出发，针对有限温度下的玻色-爱因斯坦凝聚态的特点，从正则系综的自由能函数变化的角度，推演并得出了临界温度移动的表达式。