先进材料疑固实验室 Heat transfer Laboratory of Advanced Materials Solidification Isotherms is a line that connects -12 -8 -4 0 4x/cm 6 points on a map that have the 1000℃ 1500C same temperature. 0 Isothermal surface is a surface 2099 100℃ 500℃ that all the points on the surface 50℃ 800℃ 6 have the same temperature. Temperature gradient,the maximum ratio value between the temperature difference of gradt limAT aT two isothermal surfaces alone a n-→0△n On direction. Ced Materie 上浒充通大学 SHANGHAI JIAO TONG UNIVERSITYHeat transfer Isotherms is a line that connects points on a map that have the same temperature. Isothermal surface is a surface that all the points on the surface have the same temperature. Temperature gradient, the maximum ratio value between the temperature difference of two isothermal surfaces alone a direction