bǐ wēi lì / shì / píng jià / hé dàn tóu / xiǎo xíng huà / shuǐ píng / de / guān jiàn / zhǐ biāo比威力是评价核弹头小型化水平的关键指标。Yield-to-weight ratio is a key indicator for evaluating the miniaturization level of nuclear warheads.