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  • 热辐射

    Hands are positioned above a bonfire, demonstrating thermal radiation heat transfer.

    Someone is warming their  hands over a bonfire. They don’t have to touch the fire to feel its warmth. How is warmth from the fire transferred to their  hands? In this article, you’ll find out.
    ::有人在暖暖他们的手。 他们不必碰火才能感受到火的温暖。 如何将火的温暖转移到手中? 文章中,你会发现:

    Introducing Thermal Radiation
    ::引进热辐射

    The bonfire from the opening image has a lot of . Thermal energy is the total of moving particles of matter, and the transfer of thermal energy is called . Thermal energy from the bonfire is transferred to the hands by thermal radiation. Thermal radiation is the transfer of thermal energy by waves that can travel through air or even through empty space, as shown in the Figure . When the waves of thermal energy reach objects, they transfer the to the objects, causing them to warm up. This is how the fire warms the hands of someone sitting near the bonfire. This is also how the sun’s energy reaches Earth and heats its surface. Without the energy radiated from the sun, Earth would be too cold to support life as we know it.
    ::开张图像的热火有很多。热能是物质移动颗粒的总和,热能的转移被称为 。 热能通过热辐射转移给火手。 热辐射是热能通过波浪转移热能,这些波浪可以通过空气或空空空间飘移,如图所示。 当热能波到达物体时,它们会将热能转移到物体身上,导致它们变暖。 这就是火能如何温暖坐在火炉旁的人的手。 这也是太阳的能量如何到达地球并给表面加热。 没有太阳的热能,地球将太冷,无法维持我们所知道的生命。

    Thermal radiation from the sun and a bonfire warming hands.

    A) Thermal energy radiates from the sun and transfers heat to the earth. B) Thermal energy radiates from a fire and warms a persons hands.
    :sadA) 热能从太阳辐射,将热转移到地球。 (B) 热能从火中辐射,使人手温暖。

    Thermal radiation is one of three ways that thermal energy can be transferred. The other two ways are and , both of which need matter to transfer energy. Radiation is the only way of transferring thermal energy that doesn’t require matter. 
    ::热辐射是热能可以转移的三种方式之一。 其他两种方式是,而且两者都需要能源转移。 辐射是转移热能而不需要物质的唯一方法。

    Sources of Thermal Radiation
    ::热辐射源

    You might be surprised to learn that everything radiates thermal energy, not just really hot things such as the sun or a fire. For example, when it’s cold outside, a heated home radiates some of its thermal energy into the outdoor environment. A home that is poorly insulated radiates more energy than a home that is well insulated. Special cameras can be used to detect radiated heat. In the Figure , you can see an image created by one of these cameras. The areas that are yellow are the areas where the greatest amount of thermal energy is radiating from the home. Even people radiate thermal energy. In fact, when a room is full of people, it may feel noticeably warmer because of all the thermal energy the people radiate!
    ::你可能会惊讶地知道,所有东西都会辐射热能,而不只是太阳或火等真正热能。例如,当室外寒冷时,暖热的家庭会将部分热能辐射到室外环境。隔热性差的家会比隔热性差的家更能辐射能量。可以使用特殊相机探测辐射热。在图中,你可以看到由这些相机之一所生成的图像。黄色地区是热能量最大的地区。甚至人们也会将热能辐射到户外环境。事实上,如果房间里满是人,它会感到更暖和,因为人们会受到热能的影响!

    Thermal camera image showing heat radiating from a house, with yellow areas indicating high thermal energy.

    Q: Where is thermal radiation radiating from the home in the picture?
    ::问题:照片中从家中放射的热辐射在哪里?

    A: The greatest amount of thermal energy is radiating from the window on the upper left. A lot of thermal energy is also radiating from the edges of the windows and door.
    ::A:最大数量的热能是从左上角的窗口辐射的。许多热能也从窗户和门的边缘辐射。

    Summary
    ::摘要

    • Thermal radiation is the transfer of thermal energy by waves that can travel through air or even through empty space. This is how thermal energy from a fire is transferred to your hands and how thermal energy from the sun is transferred to Earth.
      ::热辐射是热能通过波浪转移的热能,这种波浪可以通过空气或空空空间飘移,这就是如何将火灾产生的热能转移到你的手上,如何将太阳产生的热能转移到地球。
    • Everything radiates thermal energy, even objects that aren’t very warm.
      ::所有东西都会辐射热能, 甚至是不热的物体。

    Review
    ::回顾

    1. What is thermal radiation?
      ::什么是热辐射?
    2. If you sit close to a campfire, the fire warms you. Describe how thermal energy is transferred from the fire to you.
      ::如果你坐在靠近营火的地方,火会温暖你。描述热能是如何从火中转移到你身上的。