出于科技文章本质的决定，科技文章中很少用人称主语，而多用非人称主语。这些非人称主语后续谓语动词不是一般非人称主语所用的动词，而是为了人称主语所使用的的表示感觉、意识、情感或动作之类的谓语动词。于是就出现了“非人称主语+人称主语使用的谓语动词”一现象，常称之为“非人称主语句”。这样的拟人色彩是本来显得单调乏味的科技文章有了些许亮色，增添了不少生机。看例句： 
　　1 The food industry has also introduced new technologies for food storage,processing,preservation,and distribution that have reduced post-harvest losses. 
　　2 They have also introduced new technologies for food storage,processing,preservation,and distribution,which have reduced post-harvest losses. 
　　汉译： 
　　食品工业也引进了新技术，用于食品的贮藏、加工、保鲜盒分配，减少了收获后的损失。 
　　此外，非人称主语句式可以用更简洁的形式表达科技英文的各种逻辑关系，而将“逻辑标志”统统省略，即变英语的形合句为意合句。看例句： 
　　非人称主语句省略了条件句： 
　　1 Seismic measurement of travel time and amplitude define the subfurface geometry and give estimates of the acoustic impedances related to rock velocities and densities. 
　　2 If we measure the travel time and amplitude,we can define the subfurface geometry and give estimates of the acoustic impedances related to rock velocities and densities. 
　　汉译：如果我们测得地震波的走时和振幅，我们就能够确定地下的几何形状并估算与岩石速率和密度有关的声阻抗。 
　　非人称主语句省略了时间状语从句： 
　　1 Analysis of a damaged material usually requires intuitive judgement followed by real-life testing. 
　　2 When we are doing an analysis of a damaged material,usually it requires intuitive judgement followed by real-life testing. 
　　汉译：当我们在分析破损材料时，通常需要先做直观判断，再做实际实验。 
　　非人称主语句省略了因果关系句： 
　　1 The effectiveness of the electronic computer lies in its great speed and accuracy in calculation. 
　　2 The effectiveness of the electronic computer is achieved because it has great speed and accuracy in calculation. 
　　汉译：电子计算机之所以效率高，是由于其速度快，而且计算准确。 
　　非人称主语句省略了让步从句： 
　　1 Even the dissolution in water cannot enable common salt to change its chemical properties. 
　　2 Even though we dissolve the salt in water,we cannot enable common salt to change its chemical properties. 
　　汉译：即使我们将普通盐溶于水，也不能改变其化学性质。 
　　综上所述，非人称主语句现象作用是蛮大的。不光出现在科技书名文中，其他问题中也有很常见。希望对大家的英汉互译学习有所帮助。