名詞 coefficient of expansion:

1. the fractional change in length or area or volume per unit change in temperature at a given constant pressure
   同義詞：expansivity

1. The thermostat is based on the fact that different metals have different coefficients of expansion.
   恒溫器是以不同的金屬有不同的膨脹系數(shù)這一事實(shí)為根據(jù)的。