(19)We've talked recently about the importance of sustainable energy. We've also talked about the different theories on how that can be done. So far, our discussions have all been theoretical. Now I have a practical question for you all.
(20)Can you run a 140,000 kilogram train on just the steam generated by solar power？ Well, one engineer, Tim Casselman, believes it's possible. And his home city of Sacramento, California should see the technology's first test. As part of the upgrading of its rail yard. Casselman, 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 10 kilometer line drawing tourists and perhaps offering city commuters a green alternative to their cars. Casselman wants to build an array of solar magnifying mirrors at one end of the line to collect and focus heat onto water filled tubes. This would generate steam that could be used to fill tanks on a small steam train without the use of fire. 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. According to Harry Valentijn, 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 two car train for an hour or so.
Energy to drive a steam locomotive can be stored in other materials besides water (21-1)for example a team at Tohoku University in Japan has studied materials that can store large amounts of heat. When heated. These materials turn from a solid into a liquid absorbing energy as they change phase. 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 (21-2)another team at Nagoya University in Japan has tested calcium compound as an energy storage material. Heating this chemical compound drives off carbon dioxide gas leaving calcium oxide the gas can be stored under pressure and attain to recover the energy the gas is fed back over the calcium oxide. In theory says Valentijn this can create a high enough temperature to generate superheated steam.
预览三道题各选项,由选项中的 solar power、 new energy sources和 sustainable energy可推测 讲座内容与新能源或可持续能源有关;再结合 the generation of steam, drive trains with solar energ,uran facilities和 railway line等可进一步推测,讲座内容涉及火车的配套设施,可能会提及开动火车的新方法。
19.What has the speaker previously talked about？
D)。(详解)讲座开头提到,我们最近已经讨论过可持续能源的重要性,也讨论过如何实现这一点的不同 理论。到目前为止,我们讨论的都是理论层面的。也就是说,此前的讲座从理论层面对可持续能源进 行了讨论,答案为D)。
20.What is Tim Casselman trying to do in Sacramento？
A)。(详解)讲座中提到,工程师蒂姆·卡斯尔曼认为,一列14万公斤的火车仅依靠通过太阳能产生的蒸 汽就可以运转,在他的家乡,加利福尼亚州的萨克拉门托,会进行这项技术的首次测试。也就是说,他 将在萨克拉门托尝试使用太阳能驱动火车,答案为A)。
21.what has a Japanese research team tried to do？
B)。(详解)讲座中提到了两所日本大学的研究团队,而题干中并没有明确指出 a Japanese research team指的是哪所大学的研究团队,这就给解决本题增加了难度。首先,由“ a team at Tohoko University in Japan has studied materials that can store large amounts of heat”可知,该团队致力于研 究那些能够储存大量热能的材料;而从“ Another team at Nagoya University in Japan has tested calcium compound as an energy storage material."可知,该团队也是在进行能量存储材料的研究,由 此可以判断,两所学校的研究方向是一致的,都是在寻找能够储存能量的材料。因此答案为B)。