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  • General

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  • 大气中的热传递

    Lesson
    ::经验教训

     

    A tornado forming over green fields under a cloudy sky, illustrating air movement from temperature differences.

     

    Can you see energy moving?
    ::你能看见能量在移动吗?

    It's hard to see  energy  moving. But energy is the reason that air moves, and it is sometimes possible to see that. In this photo, differences in   are causing air to move—in fantastic ways!
    ::很难看到能源的移动。但能源是空气移动的原因,有时也能看到这一点。在这张照片中,气流的差异正在导致空气的移动——以惊人的方式!

    How Energy Moves Through the Atmosphere
    ::能源如何在大气中移动

    Energy travels through space or material.  Heat  energy is transferred in three ways: radiation,  conduction , and  convection .
    ::能量通过空间或材料流动,热能以三种方式转移:辐射、导电和对流。

    Radiation
    ::辐射辐射辐射

    Radiation  is the transfer of energy by waves. Energy can travel as  electromagnetic waves  through air or empty space. The Sun's energy travels through space by radiation. After sunlight heats the planet's surface, some heat radiates back into the  atmosphere .
    ::辐射是波浪的能量转移。 能源可以作为电磁波在空气或空空空间中流动。 太阳的能量通过辐射在空间中流动。 在太阳照射地球表面之后, 一些热能会再次扩散到大气层中。

    Conduction
    ::指挥

    In  conduction , heat is transferred from  molecule  to molecule by contact. Warmer molecules vibrate faster than cooler ones. They bump into the cooler molecules. When they do, they transfer some of their energy. Conduction happens mainly in the lower atmosphere. Can you explain why?
    ::在导电中,热会通过接触从分子转移到分子。 暖分子振动速度比冷分子快。 它们撞到更冷的分子。 当它们撞到冷却的分子时, 它们会转移一些能量。 导电主要发生在低层大气中。 你能解释为什么吗 ?

    Convection
    ::对等对等

    Convection  is the transfer of heat by a current. Convection happens in a liquid or a gas. Air near the ground is warmed by heat radiating from Earth's surface. The warm air is less dense, so it rises. As it rises, it cools. The cool air is dense, so it sinks to the surface. This creates a  convection current  ( Figure   ). Convection is the most important way that heat travels in the atmosphere.
    ::对流是电流的热转移。 对流发生在液体或气体中。 接近地面的空气通过地球表面的热辐射而变暖。 热空气较不稠密, 因而会上升。 随着升起, 它会冷却。 冷空气很稠密, 所以它会沉入地表。 这会产生对流流流( 图 ) 。 对流是大气中热流动的最重要方式 。

    Convection currents with arrows indicating warm air rising and cool air sinking.

     

    Convection currents are the main way that heat moves through the atmosphere. Why does warm air rise?
    ::对流洋流是热能穿过大气层的主要方式。 为什么暖气会上升?

     

    Summary
    ::摘要

    • In conduction, heat moves from areas of more heat to areas of less heat. The substances must be in direct contact.
      ::在导电中,热量从热度较高的地区移到热度较低的地区,这些物质必须直接接触。
    • In convection, materials move depending on their heat relative to nearby materials.
      ::在对流中,材料的移动取决于其相对附近材料的热量。
    • In radiation, energy moves by waves.
      ::在辐射中,能量通过波浪移动。

    Review
    ::回顾

    1. What is moving in conduction?
      ::什么是在操控中移动?
    1. What is moving in convection?
      ::什么是在对流中移动?
    1. What is radiation?
      ::什么是辐射?