per unit

基本解释

The current is the charge flow per unit time.
电流是每单位时间流动的电荷。
The insects generally produced less methane, nitrous oxide and ammonia both per unit of body mass and per unit of mass gained than pigs or cattle.
通常情况下，同猪和牛相比，每单位体重或增加每单位体重，昆虫产生更少的甲烷、一氧化氮和氨气。
The objective function on line 20 minimizes the total food cost as the total of each decision variable (amount of food) multiplied by that food's cost per unit.
第 20 行的目标函数要对食物的总体成本实现最小化，该值是每个决策变量（食物数量）乘以每单位食物成本的结果。

Fat has twice the calories per unit weight that protein or carbohydrate sugar has, as a consequence, has the greatest survival value.
单位重量中脂肪的热量含量,是蛋白质和碳水化合物的两倍,因此,脂肪才是最能维持生存的物质
耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选
As I mentioned before, fat has twice the calories per unit weight as protein and carbohydrate.
如我之前所说,单位重量中脂肪的热量含量,是蛋白质和碳水化合物的两倍
耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选
We divide that by the mass, so 0.12 kilograms, that's the mass of a regulation baseball for the major leagues, and the velocity of the baseball is 42 meters per second. So, we can cross out our units doing our unit analysis.
我们用质量来除它，质量为0，12千克，这是大多数联赛规定的棒球质量,棒球的速度为42米每秒,所以，我们可以消去单位,来做单位分析。
麻省理工公开课 - 化学原理课程节选

This portfolio generates the highest return per unit of risk of any portfolio in the universe.
FORBES: How Much International?