从2003年10月“神舟五号”载人飞船的首次成功发射,到今年第四季度值得期待的“神舟十一号”载人飞船与“天宫二号”空间实验室的交会对接,这一切无不牵动着亿万中华儿女的心,也记录着中国航天事业跨越式发展的脚步。在分享喜悦的同时,同学们或许不曾想到,宇航员在太空中呼吸的并非是纯氧而是人造空气。说到这里,同学们或许会问:在相同条件下,纯氧要比同体积的空气更能延长使用时间,为什么在航天实际操作中,却放弃了携带纯 From the first successful launch of the “Shenzhou V” manned spacecraft in October 2003 to the “Shenzhou Eleven” manned spaceship and the “Tiangong II” space laboratory that are expected in the fourth quarter of this year The rendezvous and docking of the meeting has all affected the hearts of hundreds of millions of Chinese sons and daughters, and also recorded the pace of China’s space industry’s leaping development. While sharing joy, students may not have thought that the astronauts breathe in space is not pure oxygen but man-made air. Here, the students may ask: under the same conditions, pure oxygen can extend the use of time more than the same volume of air, why in the actual operation of space, but gave up carrying pure