中文摘要：

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。为同类实验提供了理论依据．

英文摘要：

The model is based on the characteristics of BEC at finite temperature from the view of free energy variance of the canonical system. The expression of the shift of the critical temperature in BEC is derived and given and theoretical argument is provided for similar experiments in BEC in the paper.