中文摘要：

玻璃化是生物器官低温保存的最有效方式，玻璃化转变温度（Tg）是表征和研究低温保护液玻璃化过程的重要参数。目前，测定玻璃化转变温度最常用方法是差示扫描量热法（DSC）和动态热机械分析法（DMA）。本文初次尝试利用等温等压下的分子动力学模拟预测甘油水溶液（60％，wt／％）的玻璃化转变温度。在90K～273K范围内，逐个温度点模拟计算体系的恒压热容（Cp）、密度（P）、无定形晶胞体积（Vcell）、特征原子的径向分布函数和氢键的形成几率等状态参数。通过这些参数随温度的变化规律和拐点，确定甘油水溶液的Tg值。分子模拟计算结果表明：模拟计算的Tg值（160．06K～167．51K）与DSC实验测定结果（163．60K-167．10K）几乎一样。可见，分子动力学模拟（MD）可以预测甘油-水二元低温保护液的玻璃化转变温度，这种方法也可推广到其他的多元低温保护液。

英文摘要：

Vitrification was proposed to be the best way for the cryopreservation of organs. The glass transition temperature （ Tg ） of vitrification solutions is a critical parameter of fundamental importance for cryopreservation by vitrification. And Tg was usually measured by differential scanning calorimetry （DSC） and Dynamic mechanical thermal analysis （DMA）. In this paper, the Tg of the glycerol aqueous solution （60%, wt/% ） was determined by isothermal-isobaric molecular dynamic simulation （NPT-MD）. The state parameters of heat capacity at constant pressure （ Cp ）, density （ p）, amorphous cell volume （ Vcell ） and specific volume （Vspecific） were obtained by NPTMD at the temperature range of 90 K - 273 K. These parameters showed a discontinuity at a specific temperature in the state parameter versus temperature plot. The temperature at the discontinuity is taken as the simulated Tg value for glycerol-water binary solution. The results of the MDS shown that the simulation values of Tg （ 160. 06 K - 167.51 K） agree well with the DSC results （ 163. 60 K - 167. 10 K） and the DMA results （ 159 K）. It indicates that molecular dynamic simulation should be a potential method for investigating the glass transition temperature （ Tg ） of glycerol-water binary cryoprotectants and may be used for other types of cryoprotectants.