The article has expatiated the definition of the entropy function of thermodynamics, and discussed enough the irreversible process of entropy-transtion compute about the thermodynamics system.

阐述了热力学熵函数的定义，并对热力学系统的不可逆过程的熵变计算作了充分的讨论。

The inversion of its pyroelectric coefficient in polarized direction to the opposite sign and the change of the polarity of pyroelectric charge with time during phase transtion have been observed.

观测到极化方向的热释电系数改变符号及热释电电荷随时间改变极性的现象。