4. 表示原因,多用于被動(dòng)語態(tài),有時(shí)主動(dòng)語態(tài)也有此用法,常譯為“由于”。如:
* The smelting reduction process saves energy and lessens pollution by use of ore fines without any pretreatment and agglomeration.
由于使用無需任何預(yù)處理和造塊的礦粉,熔融還原法既可節(jié)約能源、又能減少污染。
5. 表示時(shí)間或時(shí)限,可譯為“到”、“在……之前”等。如:
* Spending on document management products is predicted to hit $33 billion by 2002.
到2002年,文檔管理產(chǎn)品的消費(fèi)預(yù)計(jì)將達(dá)到330億美元。
6. 表示數(shù)量或數(shù)值的增減或相差,此時(shí)by常常省譯,而數(shù)字可以照譯。如:
* The use of hot air instead of cold air reduces the amount of coke needed by more than 70%.
利用熱空氣代替冷空氣可使所需焦炭量減少70%以上。
7. by A is meant B 句型的譯
在科技英語中經(jīng)常遇到by A is meant B或by A we mean B這樣的句型結(jié)構(gòu),用于對(duì)某些科技詞匯或技術(shù)術(shù)語的解釋。A通常是表示一個(gè)術(shù)語,B則是對(duì)該術(shù)語的解釋,通??煞g為“所謂……是”。如:
* By inertia is meant that property of matter by virtue of which a body resists the influence of an outside force.
所謂慣性,指的是ー個(gè)物體賴以抵抗外力影響的ー種物質(zhì)性能。
8. by還可用于乘除法的表示。如:
* The average power is the work performed divided by the time required for the performance.
平均功率是所做的功除以做功所需的時(shí)間。