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=某汽车的四冲程的汽油机的最大功率是60KW,以最大功率工作时飞轮转速为2400r/min,活塞从气缸一端运动到另一端所扫过的容器为气缸排气量,汽油机工作时,为保证汽油有效燃烧,汽油必须与吸进空气成适当比例,这就是空燃比(可燃混合气体中空气质量与燃油质量之比),如图为该汽车汽油机的示意图,该气缸的排气量为1.8L,燃烧室(活塞移至最上方时的上方空间)容积为0.2L,空燃比14:1,可燃混合气体的密度为1.35kg/m3

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    A great invention by an 18-year-old high school student grew out of a simple problem most teenagers meet with.

    “I'm a teenager and I have a cellphone and my cellphone battery always dies,so I was really looking for a way to improve energy storage,” Eesha Khare said on Tuesday. “That's how I came across the super capacitor.”

    The teenager who came from California, and graduated from high school last week,won a $50,000 prize on May 17,2013 at the Intel International Science and Engineering Fair for creating a device that can store enough energy to charge a cellphone in 20 to 30 seconds.

    “It charges very quickly and can store a lot of energy,” Khare said. “The cool thing is that it's a lot thinner than one strand of hair.”

    Khare hasn't used her invention to recharge a cellphone yet,but she used it to power a light-emitting diode (LED) in order to show its capability(容量). If used on cellphones,the supercharger would slide on to the phone's battery to juice it up in a matter of seconds. The technology isn't available to consumers yet,and it could be years until it is.

    At an Intel event in Phoenix,Khare won the Intel Foundation Young Scientist Award,taking second place overall in the world's largest high school science research competition. She beat out more than 1,600 finalists from 70 countries. She said that she has been approached by several companies to continue her research,but she is now focused on attending Harvard University in autumn.

    “Right now,just my education,but hopefully we'll see what happens in the future,” she said about her plans. “I have a lot of interests,so we'll see what I do in the future.”