職稱英語理工類考試完形填空： 重點(diǎn)文章Humidity
Not a plant to be seen， the desert ground is too 1 。 But the air contains water， and research scientists have found a 2 of obtaining drinking water from air humidity. The system is based completely on renewable energy and is therefore autonomous.
Cracks permeate the dried-out desert ground and the landscape bears testimony to the lack of water. But even here， where there are no lakes， rivers or groundwater， considerable quantities of water are stored in the air. In the Negev desert1 in Israel2， for example， annual average relative air humidity is 64 percent -- in every cubic meter of air there are 11.5 milliliters of water.
German research scientists have found a way of converting this air humidity autonomously into drinkable water. "The process we have developed is based exclusively on renewable energy sources such as thermal 3 collectors and photovoltaic cells， which makes this method completely energy-autonomous. It will therefore function in regions 4 there is no electrical infrastructure，" says Siegfried Egner， head of the research team. The principle of the 5 is as follows： hygroscopic brine — saline solution which absorbs moisture — runs down a tower-shaped unit and absorbs water from the air. It is then sucked into a tank a few meters 6 the ground in which a vacuum prevails4. Energy from solar collectors heats up the brine，， which is diluted by the water it has 7 。
Because of the vacuum， the boiling point of the liquid is 8 than it would be under normal atmospheric pressure. This effect is known from the mountains： as the atmospheric pressure 9 is lower than in the valley， water boils at temperatures 10 below 100℃。 The evaporated， non-saline water is condensed and runs down through a completely filled tube in a controlled manner. The gravity of this water column continuously produces the vacuum and so a vacuum pump is not needed. The reconcentrated brine runs down the tower surface 11 to absorb moisture from the air.
"The concept is suitable for various water 12 Single-person units and plants 13 water to entire hotels are conceivable，" says Egner. Prototypes have been built for both sys-tem components- air moisture absorption and vacuum evaporation-and the research scientists have already 14 their interplay on a laboratory scale. In a further step the researchers in-tend to develop a demonstration 15 。
練習(xí)：
1. A dry B dirty C sandy D clean
2. A path B way C channel D road
3. A oil B wood C coal D solar
4. A when B what 。 C where D who
5. A promise B progress C prospect D process
6. A of B with C off D below
7. A absorbed B attracted C allowed D affected
8. A wetter B hotter C lighter D lower
9. A close B there C beyond D nearby
10. A gradually B distinctly C necessarily D possibly
11. A again B too C either， D more
12. A users B owners C providers D producers
13. A using B obtaining C supplying D cleaning
14. A repaired B sold C copied D tested
15. A tank B method C facility D tool
答案：ABDCD CADBB AACDC
從空氣濕度中獲取飲用水
看不到任何植物，沙漠的土地干燥無比。但是空氣中卻含有水分，科學(xué)家們已經(jīng)發(fā)現(xiàn)了從空氣中獲取飲用水的方法。這個系統(tǒng)完全依賴再生能源，因此也是自主獨(dú)立工作的。
干透的沙漠表面上布滿了裂痕，這一風(fēng)景證實(shí)了水的缺失。但是甚至在這沒有湖泊、小河和地下水的沙漠，相當(dāng)大量的水卻被存儲在空氣中。比如，在以色列的內(nèi)蓋夫沙漠，每年的相對空氣濕潤度是64%——在每立方米的空氣中有11.5毫升的水。
德國的科學(xué)家已經(jīng)發(fā)現(xiàn)了一種能自動將空氣里的水轉(zhuǎn)化成飲用水的方法�！拔覀兯芯康倪@一過程完全依賴于可再生能源，比如說太陽能集熱系統(tǒng)和光生伏打電池，這樣就使這個過程完全的自主獨(dú)立工作了。這一過程可以在那些沒有電力設(shè)施的地方進(jìn)行�！毖芯恐鞴躍iegfried Egner說。這個過程的原理如下：具有吸濕性的鹵水——吸收濕氣的鹽水溶液——從高塔形狀的裝置中流下來吸收空氣中的水分。然后被吸進(jìn)一個離地面幾公尺高的真空容器里。太陽能集熱器中的能源把鹽水加熱，然后用鹽水把吸收的水分稀釋。
由于在真空狀態(tài)下，水的沸點(diǎn)要比在正常大氣壓的時候低。這一效果也可以從山脈上得知，由于那里的氣壓比山谷的低，水在很明顯低于1000C的時候就沸騰。這一蒸發(fā)過的、沒有鹽分的水被濃縮并且通過一個完全填滿的管子有控制地流下來。水柱的重力不斷地引起真空，所以真空管是不需要的。重新濃縮的鹽水再次流下到塔的表面去吸收空氣中的濕度。
“這一理念適合不同用水者，適合個人使用的吸濕制水機(jī)及可供整問酒店用水的吸濕制水廠是有望制造成功的�！盓gner說�？諝鉂穸任蘸驼婵照舭l(fā)——這兩個系統(tǒng)的原型已經(jīng)制成——科學(xué)家們已經(jīng)在實(shí)驗(yàn)室規(guī)模驗(yàn)證了它們的交互作用。下一步科學(xué)家們想設(shè)計(jì)出一套演示設(shè)備。