对于托福考试的同学来说,不知道对于托福阅读素材积累得怎么样呢?下面就和出国留学网的小编来看看2018年托福阅读精选素材:微型机器人。
Air travel
Mechanical engineers
Tiny robots will inspect and fix jet engines from the inside
航空旅行
机械工程师
微型机器人将从内部检修喷气式发动机
IF YOU are reading this while sitting in an aircraft and are of a nervous disposition, do not be alarmed, but the temperature inside the jet engines keeping you aloft probably exceeds the melting point of the materials that those engines are made from. That they do not consequently turn into a molten mess is a feat of modern engineering. It involves a combination of tough alloys and advanced production techniques, such as 3D printing, which allow components to be made with tiny channels through which cooling air circulates. Parts exposed to the most extreme temperatures, which can reach more than 1,300°C, are given additional protection with a coating of special heat-resisting ceramics.
如果你看这篇文章时正在坐飞机,而你是个比较容易紧张的人,请不要因为接下来的文字而惊慌:带你在高空飞行的喷气式发动机内部的温度之高,可能要超过发动机制造材料的熔点。但发动机并没有因此而熔化成一堆烂铁,实在是现代工程技术的一项重大成就。这包括坚固的合金和先进的生产工艺,比如3D打印。3D打印能制造出带有细微通道的零部件,冷却用的空气可在这些通道中流通。那些暴露在最极端温度——可能超过1300°C——中的零部件还会被包裹上一层特殊的耐热陶瓷,作为额外的保护措施。
New jet engines are designed to run hot because that results in a more complete combustion, which lowers fuel consumption and cuts emissions. Hot engines, though, need nurturing. Nowadays the three big aircraft-engine makers, General Electric (GE), Rolls-Royce and Pratt &...