19.2 人造月光
章节大纲
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What an exciting scene! The picture above shows Times Square in New York City. There are so many artificial lights that it’s almost as bright as day even after the sun has gone down. Sunlight provides most of the visible light on Earth, but artificial lights are also important. That’s obvious to someone in Times Square at night. It’s also obvious to anyone who’s ever experienced a power outage after dark.
::多么令人兴奋的场景!上面的画面展示了纽约市的时代广场。 有很多人造灯光,即使在太阳下山之后也几乎和白天一样亮。 阳光提供了地球上大部分可见的光,但人工灯光也很重要。 这对时代广场上的人来说在晚上显而易见。 任何人在天黑后也显然经历过停电。Turn on the Lights
::打开灯光If you’re like most people, you don’t give it a thought when you flick a switch to turn on a light—at least not until the power goes out and you’re left in the dark! When you flick on a light switch, electricity normally flows through the light, and some type of light bulb converts the electrical energy to visible light. This can happen in various ways, depending on the type of light bulb. Several different types of light bulbs are described below. All of them are examples of artificial light , as opposed to natural light from the sun or other sources in nature.
::如果你像大多数人一样,那么当你按开关打开灯光时,你就不会给它一个想法 — — 至少在电源熄灭和被留在黑暗中之前是这样!当你按开灯关时,电力通常会通过灯光流通,而某种灯泡则会将电能转换成可见的光。 这可以有多种方式发生,视灯泡的类型而定。下面描述了几种不同的灯泡。 所有这些灯泡都是人工灯光的例子,而不是来自太阳或其他自然来源的自然光。Incandescent Light
::荧光灯An incandescent light bulb like the one pictured in the Figure produces visible light by incandescence . Incandescence occurs when something gets so hot that it glows. An incandescent light bulb contains a thin wire filament made of tungsten. When electric current passes through the filament, it gets extremely hot and emits light.
::像图中所描绘的白炽灯泡那样的白炽灯泡通过不清洁产生可见的光亮。 当某物变得如此热以致发光时,就会发生不清洁现象。 白炽灯泡含有由钨制成的细丝丝丝。 当电流穿过丝状时,电流会变得极热,会发光。Fluorescent Light
::荧光灯A fluorescent light bulb produces visible light by fluorescence. Fluorescence occurs when a substance absorbs shorter- ultraviolet light and then gives off the as visible light. The compact fluorescent light bulb (CFL) in the Figure contains mercury that gives off ultraviolet light when electricity passes through it. The inside of the bulb is coated with a substance called phosphor. Phosphor absorbs the ultraviolet light and then gives off most of the energy as visible light.
::荧光灯泡通过荧光能产生可见光,当一种物质吸收较短的紫外线光,然后释放出可见光时,便会出现荧光,紧凑型荧光灯泡(CFL)在图中含有当电力通过时释放出紫外光的汞,灯泡内涂有一种称为磷的物质,磷光会吸收紫外光,然后将大部分能量作为可见光释放出来。Neon Light
::亮光A neon light produces visible light by electroluminescence. In this process, neon or some other gas gives off light when an electric current passes through it. Other noble gases besides neon—including krypton and argon—also produce light in this way. The word “OPEN” in the sign is a neon light. It is a long glass tube that contains neon gas. When electricity passes through the gas, it excites electrons of neon atoms, and the electrons jump to a higher . As the excited electrons return to their original energy level, they give off visible light. Neon produces red light. Other gases produce light of different colors. For example, krypton produces violet light, and argon produces blue light.
::线光通过电光产生可见的光。 在这一过程中, 纳米或其它气体在电流通过时会发出光亮。 光线之外的其他惰性气体 — — 包括Krypton 和 argon — — 也会以这种方式产生光亮。 信号中的“ OPEN” 这个词是一个线光。 它是一个长的玻璃管, 含有纳温气体。 当电力通过气体时, 它会刺激有线原子的电子, 电子会跳到更高的水平 。 当兴奋的电电子回到原来的能量水平时, 它们会释放出可见的光亮光。 尼恩产生红光, 其它气体产生不同颜色的光。 例如, krypton 产生紫光, 和 argon 产生蓝色光 。Vapor Light
::蒸汽灯光A vapor light also produces visible light by electroluminescence The bulb contains a small amount of sodium or mercury as well as a of neon and argon gases. When an electric current passes through the gases, it causes the solid sodium or mercury to change to a gas and emit visible light. Sodium vapor lights, like the streetlight pictured in the Figure , produce yellowish light. Mercury vapor lights produce bluish light. In addition to lighting city streets, vapor lights are used to light highways and stadiums. The bulbs are very bright and long lasting so they are a good choice for these places.
::蒸汽灯也通过电光产生可见的光。灯泡含有少量钠或汞,以及一小撮烟雾和丙烷气体。当电流穿过气体时,电流会将固体钠或汞转化为气体并释放出可见的光。蒸汽灯像图中的街灯一样,会产生黄色的光。汞蒸汽灯会产生紫色的光。除了照明城市街道外,蒸汽灯还用来点亮高速公路和体育场。灯泡非常亮,而且长,因此是这些地方的好选择。LED Light
::LED 灯光LED stands for “light-emitting diode.” An LED light contains a material called a semi-conductor, which gives off visible light when an electric current flows through it. LED lights are used for traffic lights (see Figure ) and also indicator lights on computers, cars, and many other devices. This type of light is very reliable and durable.
::LED灯指“发光二极管”。 LED灯中含有一种称为半导体的材料,当电流流通过时,它会发出可见光。LED灯用于交通灯(见图)以及计算机、汽车和许多其他装置上的指示灯。这类灯非常可靠和耐久。Q: Some light bulbs produce a lot of in addition to visible light, so they waste energy. Other bulbs produce much less heat, so they use energy more efficiently. Which light bulbs described above would you place in each category?
::问题:有些灯泡除了能见的灯光之外,还产生很多其他的灯泡,因此它们浪费了能源。其他灯泡产生的热量要少得多,因此它们能更有效地使用能源。上面描述的灯泡会在每个类别中安装哪些灯泡?A: Incandescent light bulbs, which produce light by incandescence, give off a lot of heat as well as light, so they waste energy. The other light bulbs produce light by some type of luminescence , in which light is produced without heat. These light bulbs use energy more efficiently. Which types of light bulbs do you use?
::A:白昼灯泡通过无能产生光,它提供大量热和光,从而浪费能源。其他灯泡则通过某种光来产生光,而光是无热产生的。这些灯泡更高效地使用能量。你使用哪种灯泡?Summary
::摘要-
Most artificial lights use electricity for energy and have a light bulb that changes the electrical energy to visible light. The production of visible light can happen in various ways, depending on the type of bulb.
::大多数人造灯光都用电作为能源,并有一个灯泡将电能改变为可见光。 视灯泡类型不同,可见光的产生可以采取多种方式。 -
Types of light bulbs include incandescent, fluorescent, neon, vapor, and LED bulbs. They produce light in different ways and have different uses. Incandescent lights use heat to produce visible light, so they are not as energy efficient as the other types of lights.
::光灯泡的类型包括白电、荧光、线光、蒸气和LED灯泡,它们以不同的方式产生光,有不同用途,白灯灯用热来产生可见光,因此它们没有其他类型的灯光那样高能效。
Review
::回顾-
Compare and contrast incandescent and compact fluorescent light bulbs.
::比较和对比白炽和紧凑型荧光灯泡。 -
How do neon lights produce visible light?
::荧光灯如何产生可见光? -
Where are vapor lights used? Why are they a good choice for these places?
::蒸汽灯在哪里使用?它们为什么是这些地方的好选择? -
What are some pros of LED lights?
::LED灯有什么用?
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Most artificial lights use electricity for energy and have a light bulb that changes the electrical energy to visible light. The production of visible light can happen in various ways, depending on the type of bulb.
