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英语煎蛋小学堂视频百科100:云是如何形成的(MP3+中英双语)

cocotang 于2015-05-22发布 l 已有人浏览
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英语视频:煎蛋小学堂100:云是如何形成的,以幽默诙谐的方式为你解答那些那些你意想不到的科学小知识,含有中英双语字幕视频,mp3下载。
    小E英语欢迎您,请点击播放按钮开始播放……

If we wanted to make a cloud entirely from scratch,we'd first need a fleet of jumbo jets or several hundred hot-air balloons to haul hundreds of tons of water up to the sky.And then,somehow,we'd need to disperse all that liquid into a mist of droplets small enough to float.

如果我们想从零开始造一朵云出来,首先我们需要一队喷气式客机,或是几百只热气球,将大量的水运到空中,然后我们需要通过某种方法,把这些水变成细小到能够漂浮的水雾。

In short,it wouldn't be easy.And yet,our atomosphere manages to pump out one cloud after another all over the world at altitudes of up to 20 kilometers above sea level,using water and fuel carried all the way from Earth's surface.Cumulus clouds,for example get their start when solar energy evaporates water from oceans,plants,and soil by breaking the bonds that hold water molecules together.

总之 这很难办到,但是 我们的大气层可以,世界范围内选出一朵又一朵的云,在海拔20千米的高空,从地表弄到所有的水和燃料,例如 积云的形成,首先太阳能破坏水分子间的连接,让它们从海洋,植物体内,和土壤中的水分蒸腾出来。

As the patch of air above collects moisture and heat,cooler heavier air sinks around it pinching it off and pushing it aloft like an invisible hot air balloon.Surprisingly,this balloon's cargo doesn't weigh it down-in fact,the more water vapor it collects before lift off,the lighter it gets.As weird as that sounds,it's because water vapor is a gas just like the nitrogen and oxygen that make up most of the atmosphere.

上层的空气将水分和热量凝聚,冷空气下沉将它们包裹在一起,像一只无形的热气球带着水和热升向空中,神奇的是 热气球承载的货物不会导致坠落,事实上 在起飞前 热气球搭载的水分越多,它就越轻盈,这听上去很诡异,事实上水蒸气和组成空气的氮气,与氧气一样都是气体。

Basic physics dictates that a given volume of gas the same number of molecules regardless of what those molecules are.And water is made of H plus h plus O,which is lighter than both two Ns and two Os.So warm,humid air is even more buoyant than warm,dry air.As the invisible balloon goes up,the falling pressure outside allows it to keep ballooning,which spreads out its internal heat and lowers its temperature.

基础物理定律:一定体积的气体 分子数相同,无论哪种分子都一样,水是由H+H+O组成的,比两个N和两个O轻,因此热的湿空气要比热的干燥空气要轻,随着无形的热气球上升,外部降低的气压会让它保持膨胀,这会分散它的内热 导致降温。

Eventually,the air at the top cools enough for the water vapor there to condense into droplets,which look from after like a thin wisp of cloud.And as the rest of the balloon rises,water vapor continues to cool and condense at the same altitude,creating a flat bottomed cloud that appears to grow upward out of nothing.

最终 顶部的空气温度降低到足以令人其凝结成水珠,从远处看就像薄薄的一片小云,随着热气球剩余部分的上升,水蒸气继续在相同的海拔高度处冷凝,形成一朵平底云,这朵云就像是凭空长出来的。

What's more,as the condensing water vapor molecules bond together into liquid droplets,they release the energy they absorbed from Earth's surface when they evaporated.This heats the surrounding pocket of air,giving it lift and sucking more moist air up behind it,which cools and condenses and releases heat,which fuels lift and strengthens the updraft.Even in small cumulus cloud,the total energy released from condensation is huge-equivalent to about 270 tons of TNT.

此外,随着冷凝的水蒸气凝结成水滴,它们会释放出从地表蒸腾时吸收的能量,这些热能充盈于气囊里 令其上升,同时带动下方空气上升,这些空气冷却,凝结并且释放热量,能量上升 上升气流增强,即使只是一小朵积云,冷凝所释放的总能量也大得惊人,大约相当于270吨TNT。

And if the supply of water vapor is much  larger,the energy released can produce stratosphere high pillars of cloud wigh violent updrafts,fierce electrical storms,and grapefruit sized hailstones.Not good weather for hot air ballooning.

如果水蒸气的供给足够多,所释放的能量就可以形成平流层高度的云柱,伴随着猛烈的上升气流,造成猛烈的雷暴 下起葡萄柚大小的冰雹,这对热气球而言 可不是好天气.

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