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  • 温度

    A girl with a thermometer in her mouth looks tired and unwell, indicating a fever.

    This girl has a fever, and it makes her feel miserable. She feels achy and really tired. She also feels hot because her temperature is higher than normal. She has a thermometer in her mouth to measure her temperature.
    ::这个女孩发烧了,这让她感到很痛苦。她感到很不舒服,非常疲惫。她也感到热,因为她的温度高于正常水平。她的嘴里有一个温度计来测量她的温度。

    What Is Temperature?
    ::什么是温度?

    No doubt you already have a good idea of what temperature is. You might say that it’s how warm or cool something feels. In physics , temperature is defined as the average of the particles of matter. When particles of matter move more quickly, they have more kinetic energy, so the temperature of the matter is higher. With a higher temperature, matter feels warmer. When particles move more slowly, they have less kinetic energy on average, so the temperature of the matter is lower. With a lower temperature, matter feels cooler.
    ::毫无疑问,你已经对温度是什么有了很好的认识。你可以说温度是某物的温暖感或冷感。在物理学中,温度被定义为物质粒子的平均值。当物质粒子移动更快时,它们具有更多的动能,因此物质温度会更高。如果温度更高,物质会感到更温暖。当粒子移动较慢时,它们具有较少的动能,因此物质温度会更低。如果温度更低,物质会感觉更冷。

    How Thermometers Measure Temperature
    ::温度计测量温度

    Many thermometers measure temperature with a that expands when it gets warmer and contracts when it gets cooler. Look at the common household thermometer pictured in the Figure . The red liquid rises or falls in the glass tube as the temperature changes. Temperature is read off the scale at the height of the liquid in the tube.
    ::许多温度计测量温度, 当温度变暖时会变暖, 当温度变冷时会变大。 看看图中常见的家庭温度计。 红色液体随温度变化而上升或跌落到玻璃管里。 温度值在液管高度从比例尺上读取。

    Common household thermometers with Celsius and Fahrenheit scales.
    The red liquid in modern chemical thermometers is alcohol. Alcohol expands uniformly over a wide range of temperatures, making it ideal for use in thermometers.

    Q: Why does the liquid in the thermometer expand and contract when temperature changes?
    ::问题:为什么温度计中的液体会在温度变化时膨胀和缩缩?

    A: When the temperature is higher, particles of the liquid have greater kinetic energy, so they move about more and spread apart. This causes the liquid to expand. The opposite happens when the temperature is lower and particles of liquid have less kinetic energy. The particles move less and crowd closer together, causing the liquid to contract.
    ::A:当温度较高时,液体的粒子具有更大的动能,因此它们移动得更多,扩散得更多。这导致液体膨胀。相反,当温度较低,液体的粒子动能较少时,就会发生。粒子移动得更少,聚集得更近,导致液体收缩。

    Temperature Scales
    ::温度缩度

    The thermometer pictured in the Figure measures temperature on two different scales: Celsius (C) and Fahrenheit (F). Although some scientists use the Celsius scale, the SI scale for measuring temperature is the Kelvin scale . If you live in the U.S., you are probably most familiar with the Fahrenheit scale. The Table compares all three temperature scales. Each scale uses as reference points the and points of water. Notice that temperatures on the Kelvin scale are not given in degrees (°).
    ::图中绘制的温度计测量两个不同尺度的温度:摄氏(C)和法赫里内海特(F)。虽然有些科学家使用摄氏尺度,但测量温度的SI尺度是克尔文尺度。如果您居住在美国,您可能最熟悉法赫里海特尺度。表格比较了所有三个温度尺度。每个尺度使用水的参考点和点。请注意,克尔文尺度的温度没有按度(°)给定。

    Scale Freezing Point of Water Boiling Point of Water
    Kelvin 273 K 373 K
    Celsius 0 °C 100 °C
    Fahrenheit 32 °F 212 °F

    Because all three temperature scales are frequently used, it’s useful to know how to convert temperatures from one scale to another. It’s easy to convert temperatures between the Kelvin and Celsius scales. Each 1-degree change on the Kelvin scale is equal to a 1-degree change on the Celsius scale. Therefore, to convert a temperature from Celsius to Kelvin, just add 273 to the Celsius temperature. For example, 10 °C equals 283 Kelvin.
    ::因为所有三个温度尺度都经常使用,所以了解如何将温度从一个尺度转换为另一个尺度是有用的。在凯尔文和摄氏尺度之间转换温度很容易。 凯尔文尺度的每1度变化等于摄氏尺度的1度变化。 因此,如果将温度从摄氏度转换为凯尔文,只需将273度转换为摄氏温度。 例如,10°C等于283凯尔文。

     

     

    Q: How would you convert a temperature from Kelvin to Celsius?
    ::问:你如何将热量从开尔文转换为摄氏度?

    A: You would subtract 273 from the Kelvin temperature. For example, a temperature of 300 Kelvin equals 27 °C.
    ::A:你会从开尔文温度中减去273。例如,300开尔文的温度等于27°C。

    Converting between Celsius and Fahrenheit is more complicated. The following conversion factors can be used:
    ::摄氏度和华氏度之间的转换更为复杂。可以使用以下换算系数:

    Celsius → Fahrenheit : (°C × 1.8) + 32 = °F
    Fahrenheit → Celsius : (°F - 32) ÷ 1.8 = °C

    For example, to convert 10 °C to Fahrenheit, use the first conversion factor:
    ::例如,要将 10 °C 转换为 Fahrenheit, 请使用第一个转换系数 :

    (10 °C × 1.8) + 32 = 50 °F

    Q: The weather forecaster predicts a high temperature today of 86 °F. What will the temperature be in Celsius?
    ::问题:天气预报器预测今天的高温为86°F。温度以摄氏度计是多少?

    A: To convert 86 °F to Celsius, use the second conversion factor:
    ::A:将86°F转换为摄氏度,使用第二个换算系数:

    (86 °F – 32) ÷ 1.8 = 30 °C

    Use the PLIX Interactive below to convert  30 degrees Celsius to degrees Fahrenheit:
    ::使用下面的 PLIX 交互作用将 30 摄氏度转换为华氏度 :

     

     

    Summary
    ::摘要

    • Temperature is the average kinetic energy of particles of matter.
      ::温度是物质粒子的平均动能。
    • A thermometer can measure temperature with a liquid that expands when it gets warmer and contracts when it gets cooler
      ::温度计能测量温度 温度计能测量温度 温度计能测量温度 温度计能测量温度
    • The SI scale for measuring temperature is the Kelvin scale. Celsius and Fahrenheit temperature scales are also commonly used. You can use conversion factors to convert temperatures between the different scales.
      ::用于测量温度的SI级尺度是Kelvin级尺度。摄氏度和Fahrenheit级温度尺度也是常用的。您可以使用转换系数在不同尺度之间转换温度。

    Review
    ::回顾

    1. What is temperature?
      ::什么是温度?
    2. Explain how the thermometer pictured in this article measures temperature.
      ::解释这篇文章中的温度计如何测量温度。
    3. Assume that the temperature outside is 293 Kelvin but you’re familiar only with the Fahrenheit scale. Do you need to wear a hat and gloves when you go outside? To find out, convert the Kelvin temperature to Fahrenheit. (Hint: Convert the Kelvin temperature to Celsius first.)
      ::假设外面的温度是293 开尔文,但你只熟悉法赫伦海平面尺度。 外出时你需要戴帽子和手套吗? 要发现,请将开尔文温度转换为法赫伦海平面。 (提示:先将开尔文温度转换为摄氏度。 )