yán jiū rén yuán / tōng guò / cè liáng / wēn dù / hé / yā lì / gū suàn / qì tǐ / de / nèi néng / biàn huà研究人员通过测量温度和压力,估算气体的内能变化。Researchers estimate changes in a gas's internal energy by measuring its temperature and pressure.