(单词翻译:单击)
Recording 2
录音 2
We've talked recently about the importance of sustainable energy. We've also talked about the different theories on how that can be done.
我们最近谈到了可持续能源的重要性。我们也讨论了关于如何做到这一点的不同理论。
So far, our discussions have all been theoretical. Now I have a practical question for you all.
到目前为止，我们的讨论都是理论性的。现在我有一个实际的问题要问大家。
Can you run a 140, 000 kilogram train on just the steam generated by solar power? Well, one engineer, Tim Castleman, believes it's possible.
仅仅依靠太阳能产生的蒸汽，你就能运行14万公斤的火车吗？工程师蒂姆·卡斯尔曼认为这是可能的。
And his home city of Sacramento, California should see the technology's first test.
他的家乡加州萨克拉门托应该会有这项技术的第一次测试。
As part of the upgrading of its rail yard, Castleman, who is an inventor and self-proclaimed steam visionary, is campaigning for a new steam train that runs without any fire and could run on an existing ten-kilometre line, drawing tourists and perhaps offering city commuters a green alternative to their cars.
卡斯尔曼是一个发明家，自称在蒸汽方面有远见卓识，铁路站场正在升级，他在推广一种新型蒸汽火车，不用火，可以在现有的10公里长的线路上运行，吸引游客，或许还能为城市通勤者提供一种绿色的汽车替代品。
Castleman wants to build an array of solar magnifying mirrors at one end of the line to collect and focus heat onto water-filled tubes.
卡斯尔曼想要在线路的一端建造一组太阳能放大镜收集热量并把热量集中到充满水的管道上。
This would generate steam that could be used to fill tanks on a small steam train without the use of fire.
这将产生蒸汽，可以不用火就充满小蒸汽火车的水箱。
"Supplying power to trains in this way would offer the shortest distance from well to wheels," he says, "with the least amount of energy lost."
他说：“用这种方式为火车提供动力，将使井口到车轮之间的距离最短，而且损失的能源最少。”
According to Harry Valentine, a Canadian engineer who is researching modern steam technology, a special tank measuring 2 by 10 metres could store over 750 kilowatt hours of energy as high-pressure steam, enough to pull a 2-car train for an hour or so.
研究现代蒸汽技术的加拿大工程师哈里·瓦伦丁(Harry Valentine)说，一个宽2米、长10米的特殊水箱可以储存750千瓦时的高压蒸汽，足够拉动一列两节车厢的火车行驶一个小时左右。
Energy to drive a steam locomotive can be stored in other materials besides water.
驱动蒸汽机车的能量可以储存在除水以外的其他物质中。
For example, a team at Tohoko University in Japan has studied materials that can store large amounts of heat.
例如，日本东光大学的一个研究小组研究了可以储存大量热量的材料。
When heated, these materials turned from a solid into a liquid absorbing energy as they change phase.
当这些材料受热时，它们会从固态变成液态，并在相变时吸收能量。
The liquid is maintained above its melting point until steam is required, at which point the liquid is allowed to turn back into a solid, releasing its stored energy.
不需要蒸汽时，液体保持在熔点以上，需要蒸汽时液体才能变成固体，释放其储存的能量。
Another team at Nagoya University in Japan has tested calcium compound as an energy storage material.
日本名古屋大学的另一个团队已经测试了可以作为储能材料的钙化合物。
Heating this chemical compound drives off carbon dioxide gas, leaving calcium oxide. The gas can be stored under pressure in a tank.
加热这种化合物会排出二氧化碳，产生氧化钙。气体可以在压力下储存在储罐中。
To recover the energy, the gas is fed back over the calcium oxide. "In theory," says Valentine, "this can create a high enough temperature to generate superheated steam."
为了回收能量，气体重新与氧化钙反应。“理论上，”瓦伦丁说，“这可以产生一个足够高的温度来产生过热的蒸汽。”
Questions 19 to 21 are based on the recording you have just heard.
请根据你刚刚听到的录音回答第19题到21题。
19. What has the speaker previously talked about?
19. 说话者之前谈到了什么？
20. What is Tim Castleman trying to do in Sacramento?
20. 提姆·卡斯特曼在萨克拉门托想做什么？
21. What has a Japanese research team tried to do?
21. 日本的研究团队试图做什么？
