A mathematical model was developed to investigate mass flow rates in the heat transfer pipes of the air side heat exchanger with and without distribution pipes for an air source heat pump.
They found a strong correlation between the time an airmass had spent over the forest and the load of particles it carried, showing that the trees must be the source.
他们发现气团在森林上空滞留的时间和其携带的微粒有极大的关连，显示树木是微粒的来源。
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The compressed air is the main safe energy source for mass industrial production.