1·It has been proved that the process of coal and gas outbursts is not an adiabatic process accepted by most researchers but a polytropic process that is nearly an isotherm process.
研究结果表明，煤与瓦斯突出不是大多数学者认为的绝热过程，而是一个偏向于等温过程的多变过程。
2·The polytropic efficiency is one of the most significant indicators which are used to judge the economical efficiency of the units.
离心式压缩机组广泛应用于石油天然气工业领域，而多变效率是衡量该系统运行经济性的重要指标之一。
3·The polytropic processes are used for the performance analysis of Stirling cycle.
应用多变过程来分析斯特林循环性能。