coefficient of heat convection

例句：

1. 1. The coefficient of thermal conductivity is an important factor in determining the efficiency of a heat exchanger.
   热传导系数是决定换热器效率的重要因素。
2. 2. The coefficient of thermal conductivity can be used to calculate the temperature gradient across a material.
   热传导系数可以用来计算材料内部的温度梯度。
3. 3. The coefficient of thermal conductivity is affected by factors such as the material's composition and the size of the sample.
   热传导系数受到材料成分和样品尺寸等因素的影响。