英語中表示倍數(shù)減少的表達方法
(一)a is n times as small (light,slow,…)as b.
a is n times smaller (lighter, slower,…) than b.
以上兩句均應(yīng)譯為:a的大小(重量,速度,……)是b的1/n[或a比b小(輕,慢,……)(n-1)/n].
e.g. The hydrogen atom is near1y l6 times as light as the oxygen atom. 氫原子的重量約為氧原子的1/16(即比氧原子約輕15/16)。
e.g. This sort of membrane is twice thinner than ordinary paper. 這種薄膜比普通紙張要薄一半(即是普通紙厚度的1/2)。
注:當相比的對象b很明顯時,than/as b常被省去。
(二)decrease n times/n——fold
decrease by n times
decrease by a factor of n
以上三式均譯為:減少到1/n[或:減少(n-1)/n].
decrease常被reduce,shorten,go/slow down等詞替代。
e.g. Switching time of the new-type transistor is shortened 3 times. 新型晶體管的開關(guān)時間縮短了1/3(即縮短到2/3)。
e.g. When the voltage is stepped up by ten times, the strength of the current is stepped down by ten times. 電壓升高9倍,電流強度便降低9/10(即90%)。
e.g. The equipment reduced the error probability by a factor of 5. 該設(shè)備誤差概率降低了4/5.
(三)there is a n-fold decrease/reduction… 應(yīng)譯為:減至1/n [或:減少(n一1)/n].
這個句型還有其它一些形式,
e.g. A rapid decrease by a factor of 7 was observed. 發(fā)現(xiàn)迅速減少到1/7.
e.g. The principal advantage of the products is a two-fold reduction in weight. 這些產(chǎn)品的主要優(yōu)點是重量減輕了1/2.
英語在表述或比較倍數(shù)時,無論使用什么句型(除了不含倍數(shù)詞的again句型外)都包括基礎(chǔ)倍數(shù)在內(nèi),因此都不是凈增或凈減n倍,而是凈增或凈減n-1倍。