老师题源报精读课第四课

1、第 6 篇 -科学类（选自卫报 2014 年 11 月）P344A mirrords heato the frigid expanse of space has been designed byscientists to replace air-conditioning unitst keep buildings cool on Earth.Researchers beve the mirror could slash the amount of energy used to control airtemperatures in business premises and shopcentre

2、s byng away wither-gry cooling systems.Around 15% of the energy used by buildingshe US goes on air conditioning, butthe researchers calculationggestt in somecases, the mirror could compleyoffset the need for extra cooling.In a rooftop comparison of the device in Stanford, California, scientists foun

3、dtwhile a surface paed black reached 60C moren ambient temperature in sunlight,and bare aluminium reached 40C more, the mirror was up to 5C cooler n thesurrounding air temperature.“If you cover significant parts of the roof with this mirror, you can see how mucher it can save. You can significantly

4、offset the electricity used for air conditioning,”said Shanhui Fan, an expert in photonics at Stanford University who led the developmentof the mirror. “In some situations the compuions say you can compley offset the airconditioning.”Buildings warm up in a number of different ways. Hot water boilers

5、 and cookingfacilities release heato their immediate surroundings. In hot countries, warm air comeshrough doors and windows. Then there is visible light and infra-red radiation from thesun, which also heat up buildings.The Stanford mirror was designed in such a wayt it reflects 97% of the visiblelig

6、htt falls on it. But more importantly, it works as a thermal radiator. When themirror is warmed up, it releases heaa specific wavelength of infrared lightt passeseasily through the atmosphere and outo space.To make anything cool requires what engineers call a heat sink: somewhere to dumpunwanted hea

7、t. The heat sink has to be coolern the objectt needs cooling or it willnotts job. For exle, a bucket of ice will cool a bottle of wine because ites asink for heathe liquid. Use a bucket of hot coals and the result will the very different.The Stanford mirror res on the ultimate heat sink: the univers

8、e itself.The mirror is built from several layers ofr-thaterials. Thelayer isreflective silver. On top of this are alternating layers of silicon dioxide and hafnium oxide.These layers improve the reflectivity, but also turn the mirroroa thermal radiator.When silicon dioxide heats up, it radiates the

9、heat as infrared ligha wavelength ofaround 10 micrometres. Since there is very littlehe atmospheret absorbs attwavelength, the heat passes straight out tospace. The total thicknessof the mirror isaround two micrometres, or two thousandths of a millimetre.“The cold darkness of the universe can be use

10、d as a renewable thermodynamicresource, even during the hottest hours of the day,” the scientists write in Nature.ests,the mirror had a coolinger of 40 watts per square metre at ambient temperature.Writinghe journal, Fan puts the installed cost of mirrors at betn $20 and$70 per square metre and calc

11、ulates an annual electricity saving of 100MWh per year ona three storey building.Fan saidt the mirror could cool buildings-or other objectssimply by putting it indirect contact with them. Coating the roof of a building with the mirror would preventheating from sunlight but do little to remove heat f

12、rom itserior. More likely, the mirrorwould be used to cool water or some other fluidt would then be pumped around thebuilding.He ruled out the idea of using the mirrors to slow down global warming. “Roofspace accounts for only a small portion of the Earthrface, so at this powe dontthink this would b

13、e a geoengineering solution. Rather, our contribution on the greenhouse gas emisie is simply to reduce electricity consumption,” he said.“Im really excited by the potential is and the applications for cooling,” saidMarin Soljai, a physicisMIT. “You could use this on buildings so you have to spendmuc

14、h less on air conditioning or maybe you wouldnt need iall. You could put it ontop of shopmalls. Wilarge enough surface you could get substantial cooling.”【词语积累】frigid adj. 寒冷的premises n. (企业)营业场所thermal radiator 热辐射计infrared adj. 红外线的silicon dioxide 二氧化硅radiate vt. 放射thermodynamic adj. 热力的geoenginee

15、ring n. 地球工程学substantial adj. 大量的【长难句】【参考译文】科学家正在设计一种可以把热量传送到寒冷广袤太空的镜面，用来取代为建筑降温的空调组。研究认为，该技术可取代商务场所和购物中心里高能耗的制冷系统，从而大幅降低制冷的能耗。在，空调耗电量占总建筑物用电量的 15。而研究的计算结果表明，该镜面完全可以抵消对额外制冷电量需求。科学家在加利福尼亚斯坦福大学的屋顶设备对比试验中发现，在光照下，黑面板的表面温度比环境温度高， 铝面板比环境温度高，而镜面的温度却比周围气温低了将近。“如果用镜面来覆盖大部分的屋顶，你就知道能节省多少电量了。这样做可以有效抵消空调制冷的耗电量，”

16、该镜面研发人、斯坦福大学光电学说道。“计算结果证明，在某些情况下，它可以完全抵消空调制冷的耗电量。”建筑物温度升高是由多种原因造成的。热水锅炉和烹饪设施向周围环境热量。在气候炎热的国家，热气透过门窗进入室内。的可见光和红外辐射使得室内温度升高。斯坦福大学设计的镜面可以反射掉 的可见光。但更重要的是，它像一个热辐射计。当镜面温度升高时，它能够通过特定波长的红外线，轻轻松松把热量输送至大气层和外太空。制冷需要使用热沉，即吸收多余热量的设备。热沉的温度应低于需制冷物体的温度，否则制冷无法完成。比如，一桶冰能降低一瓶酒的温度，因为冰成为瓶中液体所含热量的热沉。如果用一桶燃烧的煤来制冷，效果就会截然相反

17、。斯坦福研发的镜面依靠的就是宇宙这个终极热沉。该镜面由若干层薄片材料制成。第一层是银反射膜。然后是二氧化硅和氧化铪交替层。这些涂层能有效提高反射率，同时把镜面变成一个热辐射计。二氧化硅温度升高时，会通过约 10 微米波长的红外线辐射热量。由于大气中几乎没有物质能吸收这一波长的红外线，因此热量直接传送到太空。镜面的总厚度在 2 微米左右，即千分之二厘米。科学家在自然杂志中撰文写道：“即使在温度最高的时刻，宇宙的寒冷和也可用作可再生的热力资源。”试验结果显示，室温下该镜面的冷却能力为每平方米 40 瓦特。文章中，估算该镜面的安装成本介于每平方米 20 到 70 美金之间，预计一栋三层的楼房一年能节

18、省 100 兆瓦时的电。说，使镜面与楼房或其他物体的表面接触，就能达到降温的目的。将镜面覆盖到楼顶上，便可有效辐射的热量。但它对降低室温作用甚微。镜面反倒更可能给楼房管道中的水或其他液体降温。他打消了利用该镜面技术延缓全球变暖的念头。“屋顶面积只占地球表面的极小一部分，因此认为该技术不能提供地球工程解决方案。镜面技术对温室气体排放的贡献，仅仅在于减少耗电量而已。”“这一技术的发展潜力及其在制冷方面的应用令我感到振奋，” 麻省理工学院物理学家西克说道。“你可以安装在楼顶上，这样空调的耗电量会大大降低，你甚至不需要空调制冷。你还可以安装在商场的屋顶。因为屋顶面积比较大，将会看到实质性的制冷效果。”

19、第 7 篇 -卫生类（选自科学 2015 年 4 月）P250When nature calls, about 1 billion peoplehe develoworld still head to anopen field, the bushes, or a body of water to defecate. The practice has contributed tohigh rates of diarrheal diseases, espelly, where moren half of people dontuse latrines. Prime Minister Narendr

20、a Modi, who tooker last May, has pledged tobuild 111 million toilets as part of the Cleanmis, a saniionn. Onegoal is to end open defecation by October 2019.But exactly how to get there irprisingly controversial. Some nonernmentalanizations andernment offils in develocountries have longpushed foreduc

21、ationnsteaching people about the health benefits of using toilets. Othersadvocate subsidizing latrine costs for the poor, but some economists arguet finanlaid for cheap toilets could backfire by discouraging those who dont receive it frombuying latrines on their own for a highrice.Now, one of the la

22、rgest controlled experiments to examine saniion strategies,conducteds neighbor Bangladesh and published online thisk in Science,comes down strongly in favor of cash. After comparing three policiesoren 100villages, the authors foundt the key to getting people to build latrines is to subsidizethe cost

23、. They also foundt funding poor villagers to install latrines can encouragetheir unsubsidized neighbors to follow suit in a benefil spillover effect.Given the enormous emphasis Prime Minister Modi has placed on eliminating opendefecation, these results should be of greaterest to thenernment. Itls us

24、t cutting the price of quality toilets is the single mosterful instrument ingetting people to stop defecating outside,” says economist Abhijit Banerjee of theMassachusetts Institute of Technology in Cambridge, who was not involvedhe study. Others caution, however,t building toilets doesnt always mea

25、n people will usethem or be healthier, ort findings in Bangladesh will be relevant to culturally different.The experiment, funded by the Bill & Melinda Gates Foundation in Seattle,Washington, took placehe Tanore, a poor, rural district in northwest Bangladesh.Although open defecation rates are only

26、3% overall in Bangladesh,anore, aboutone-third of adults still follow the practice or use unhygienic latrines, such as “hanging”latrinest emptyo waterways. Yale University economists Mushfiq Mobarak andJames Levinsohn and Raymond Guiteras of the University of Maryland, College Park,chose 107 village

27、s with 18,254 poor households. Some villages received education on theimportance of saniion, and some received only information on buying and installing alatrine. In a third program, 25% to 75% of villagers received vouchers through a lottery.Each voucher was good for about 50% off the $29 to $58 co

28、st of an installed pour flushlatrinea designt carries feto a sealed pit.The vouchers made all the difference, the researchers found 13 months later.Education alone or information on how to acquire a latrine did not significantly increasethe portion of people who owned or had acs to a hygienic latrin

29、e. But education plusvouchers resulted in significant changefor exle, a rise in hygienic latrine ownershipfrom 22%he control group to 45% in villages where half the households receivedvouchers and education. The study also found a reduction of 14% in open defecation inthese same villages.The big sur

30、prise wast even people who didnt receive a voucher were moreinclined to buy a latrine at full price if their neighbors received vouchers. This effect wasstronger when a highroportion of households received vouchers. People were alsomore likely to use their vouchers in neighborhoods where more househ

31、olds receivedvouchers. For policymakers, the message is clear, Mobarak says: “If you are going to usesubsidies, it makes sense to allocate them in a coordinated manner sot many people ina community all get subsidies joly.”Varande, an economist with the Dalberg consulting firmumbai,who has advised th

32、enernment and the World B about saniion policies,says the results“resonate with our experience on the ground. Both subsidies andeducation need to happen in a well-orchestrated sequence.” To Sumeet Patil, andemiologist and economist with the Network for Engineering and Economics Researchand Managemen

33、tumbai, the result should settle the debate over toilet subsidies.But others say an encouraging result in Bangladesh may not say much about,where the hygiene problem is much bigger. A survey released last year by theResearch Institute for Compasate Economics (RICE) in New Delhi foundt manyns who hav

34、e acs to a hygienic latrine still prefer open defecation, particularlyHindus, who were not representedhe Bangladesh study. The reasons may involveHindu caste system befst allowing feto accumulate in a latrine is impure andt only an“untouchable” can remove them, says RICEExecutive Director Dean Spear

35、s. He adds:“I would just say we should be verycareful about generalizing to Hindu rural north.”【词语积累】defecate vi. 排便 diarrheal n. 痢疾 latrine n. 厕所 saniion n. 公共卫生install vt. 安装 spillover effect 溢出效应 unhygienic adj. 不卫生的allocate vt. 分派hygiene n. 卫生generalize vi. 普及【长难句】【参考译文】在发展中国家，大约有 10 亿人仍在空地、丛林甚至水塘边解决内急。这种导致了腹泻的高，尤其是在，一半以上的人不使用公共厕所。去年五月刚执政的首相纳伦保证修建 1.11 亿个厕所，以作为“更加清洁”这一卫生活动的一部分。其中一大目标就是在 2019 年 10 月之前终结露天排泄的行为。但是如何达到这个目标存在着很大的争议。一些发展中国家的非的机构和一直推行教育宣传活动，来告诉人们使用厕所的卫生益处。其他人支持为穷人提供修建厕所的。但是一些认为对廉价的厕所提供补贴，可能会产生事与愿违的效果，因为这会挫伤那些自己花