Summary
从空气中提取大量淡水是可行的. 科学们了解到空气相对湿度超过100%后,继续降低空气温度, 空气中的水分会自动释放出来. 然而这种方式依赖于气温是否能下调到合适的范围, 否则效果也不尽如人意, 于是试图通过外部设备解决提取液态水的问题. 工程师找到一种分子表面积大且分子间作用力适中的元素: 锆. 同时为保证水分子在多孔的锆分子间稳定吸附, 还研发出一种固态泡沫, 这使得本就昂贵的液态水提取系统变得更加昂贵.
It is available to win a lot of water from the air. Scientist know that water molecules will be released when the temperature of air is cooled to the point where its relative humidy exceeded 100%. The ease with this solution depends on temperature of the air could be cooled, otherwise nothing much to be show for it. Thus people try to extract liquid water with special traps. Scientist find zirconium, which has two properties---one is a large surface area, the other one is a appropriate Van der Waals response. Meanwhile, a solid foam is add into the system to held water adsorped between porosity zirconium molecules. This way makes an already costly technogy even more expensive.
Vocabulary
1. fresh water: 淡水
2. desalination: 海水淡化
3. a source of brine: 盐水源
4. in turn:
5. water vapour: 水蒸气
6. moisture: 水分, 湿度
7. vapour: 水蒸气
8. effectively and cheaply: 有效而廉价
9. depends on sth: 取决于, 依赖于
10. independent: 独立的
11. dependent: 依赖于, 取决于
12. relative humidity: 相对湿度
13. mist: 雾
14. dew: 露水
15. nocturnal: 夜的, 夜间的
16. pluck: 拔, 使脱颖而出; 解救; 胆识, 勇气
17. molecule: 分子
18. pertinent: 相关的
19. porous: 能渗透的, 有气孔的, 多孔渗水的
20. porosity: 有孔性, 多孔性
21. circulate: 流通, 循环, 传播
22. ingredient: 成分, 因素
23. zirconium: 锆
Context
如果你生活在沙漠中, 保持淡水的供应是个挑战. 一个答案是海水淡化, 但这需要一个盐水源来去除盐, 因此也要求你所在的沙漠靠近大海. 即便是在内陆沙漠, 空气中的水分也常常以水蒸气的形式存在. 问题是如何有效而廉价地提取这些蒸汽.这就是两组研究人员---一组来自康涅狄格大学, 另一组来自伯克利加利福尼亚大学---所希望他们能够做到的. 从空气中获取水分的难易程度取决于空气的相对湿度.
If you live in a desert, maintaining fresh water is a challenge. One answer is desalination, but that needs a source of brine from which to remove the salt, which in turn requires that your desert be near the sea. Even in inland deserts, moisture is often present in the air as water vapour. The problem is extracting this vapour effectively and cheaply. That is what two groups of researchers --- one at the University of Connecticut, the other at the University of California, Berkerly--- hope they have managed to do.
The ease with which water can be won from air depends on that air's relative humidity.
这是其目前水蒸气含量的计算方式, 作为其在当前湿度下最大可能蒸汽含量的百分比. 100%的相对湿度意味着空气中含有尽可能多的水蒸气.
This is a measure of its current vapour content as a percentage of its maximum possible vapour content at its current temperature. A relative humidity of 100% means that air in question is holding as much water vapour as it possbily can.
因此, 让空气失去一部分水分的一个好办法是将其冷却到相对湿度超过100%的程度. 有时, 夜间会自然发生这种情况, 造成雾和露水的形成.
A good way to get the air to give up some of its moisture is therefore to cool it to the point where its relative humidity exceeds 100%. Sometimes this happens naturally at night, causing mist and dew form.
在液态水稀少的地区, 这些水可以用特殊的捕集器收集. 但如果这个问题降温并不能将空气的相对湿度提高到100%, 那么用特殊材料制造胶水器可能会给大自然带来帮助. 吸附是将相对湿度小于100%的空气中的水分子吸附到固体材料表面的过程. 分子通过一种被称为分子间作用力的静电连接与相关表面上的分子相连接而固定在那里的.
These can be collected in some special traps in areas where liquid water is otherwise rare. But if nocturnal cooling does not bring all the way up to 100% relative humidity, building water traps out of special materials may give nature a helping hand. Adsorption is a process which plucks water molecules from air that has less than 100% relative humidity, by attaching them to the surface of a solid material. The molecules are held there by electrostatic connections called Van der Waals forces that link them with the molecules of the pertinent surface.
因此, 用这种方法收集水需要一种具备两种特性的材料. 一个是很大的表面积, 另一个是适当的分子间作用力反应.
To collect a lot of water this way therefore requires a material which has two properties. One is a large surface area, the other one is an appropriate Van der Waals response.
利用这一原理的实验捕集器是用一种叫做金属-有机骨架的物质制成的. 这些是多孔的分子网络, 空气可以通过它们循环. 它们的多孔性使它们具有很大的表面积.
Experimental traps that employ this principle have been made using substances called metal-organic frameworks. These are porous molecules networks through which air can circulate. Their porosity gives them have a huge surface area.
通过选择正确的材料 , 如锆, 它们可能获得必要的分子间的作用力性质. 但锆价格昂贵. 而且, 一旦被吸附, 水就必须被释放.
By picking up the right ingredients, such as zirconium, they can be given the necessary Van der Waals properties. Zirconium is, however, costly. Moreover, once adsorbed, the water must then be released.
这意味着加热吸附物质, 太阳升起后即提供的热量. 在此, 金属-有机骨架出现了一个问题. 它们更倾向于反射而不是吸收阳光, 因此不能很好地加热.
This means warming adsorptive material-the warmth being provided by the sun, once it has risen. Here, metal-organic frameworks present a problem. They tend to reflect sunlight rather than absorbing it, and so do not heat up well.
为了克服这个问题, 工程师們在系统中加入了由铜制成的固体"泡沫". 它们在太阳下受热, 将一部分热量传递到邻近的金属-有机骨架上, 在那里被吸附的水需要被释放出来. 这种方法起了作用, 但添加泡沫这种方法让本就昂贵的技术更加昂贵.
To overcome this, engineers build solid foams made of copper into the system. These heat up in the sun and transfer part of their heat to parts of the adjacent metal-organic framework where adsorped water need to be released. This works, but add foams makes an already costly technology even dearer.