Intensity is a measure of power per unit area, and even a laser that emits only a few milli-watts can produce a lot of intensity in a beam that's only a millimeter in diameter.

强度是每单位面积的度量，即使一个仅能产生几毫瓦能量的激光器也能产生一个直径只有一毫米的高强度光束。

youdao

But the conventional activated sludge process technology has some shortcomings: long water residence time, low processing power per unit area, large area reactor, sludge bulking and so on.

但是传统的活性污泥法工艺存在工艺流程长、污水停留时间长、单位面积处理能力低、反应池占地面积大、污泥膨胀等缺点。

youdao

But the sober message about wind and solar applies to all renewables: All renewables, much as I love them, deliver only a small power per unit area, so if we want renewable facilities to supply power on a scale at all comparable to our consumption, those facilities must be big.

CNN: Commentary: Let's get real about alternative energy