英文书摘精选 How Does Ice Cool Drinks?冰块是如何使饮料冷却的?
时间：2018-12-28 作者：英语课 分类：初学者听力文摘精选
Here’s something we tend to take for granted: drop a few ice cubes into a glass of water at room temperature, and in a few minutes the water will cool. How does this work?
有件事情我们总觉得理所当然：室温下把一些冰块放入水中，过几分钟水就会变凉。但这到底是什么原理呢？
Heat is a measure of molecular 1 activity: the faster a thing’s molecules 2 move, the more heat that substance contains. And because everything is made of molecules, and molecules are in constant motion, everything contains at least some heat.
热量是衡量分子运动的一个指标：一个物体分子的移动越快，物体所包含的热量就越多。由于一切物体都由分子组成且分子总在不断地运动，所以每个物体或多或少都包含着一些热量。
As we know, ice is colder than room temperature water. Because ice molecules move slowly and cluster tightly together, they produce a relatively 3 low amount of heat. When ice is placed in a glass of water whose molecules are moving at a greater rate, the ice begins to absorb energy, because heat always travels from regions of relative warmth to colder areas in order to equalize temperatures. In other words, ice absorbs heat from the water.
我们都知道，冰的温度要比温水低。由于冰分子移动缓慢且相互连结得十分紧密，因此它们产生的热量相对较少。如果把冰块放入一杯分子移动较快的水中，冰块就会开始吸收热量，这是由于热量总是会从高温地带转移到低温地带，从而使温度均衡。也就是说，冰块从水中吸收热量。
As the water molecules lose energy, they begin to slow down, and consequently to cool. So, it’s kind of the opposite of what we might think: when we put ice in water, the ice doesn’t give its cold to the water, it takes heat from the water.
水分子在失去热量后运动减慢，继而水温降低。这可能跟我们所想的恰恰相反：当我们把冰放入水中，冰不会把自己的低温传给水，而是从水中吸收热量。
The cooling process actually happens in stages. Because ice floats, it cools the water near the top of the glass first. As the top layer of water cools, its density 4 increases, causing it to sink to the bottom. The lower layer, less dense 5 and therefore more buoyant, floats to the top and is cooled in turn.
这个冷却过程实际上是分阶段进行的。由于冰块会浮在水面上，所以最上层的水会先变凉。上层的水冷却后，它的密度会增大，上层的水会往下沉。而下层的水由于密度较小于是会上浮，进而又被冷却，依次循环下去。
- The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
- For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。
- The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
- Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。
- The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
- The operation was relatively painless.手术相对来说不痛。