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标题: 【揽瓜阁2.0】Day1 2020.06.15【社会科学-科技】 [打印本页]

作者: 妥妥 时间: 2020-6-14 20:15
标题: 【揽瓜阁2.0】Day1 2020.06.15【社会科学-科技】

揽瓜阁俱乐部第二期

Day1 2020.06.15

【社会科学-科技】

Which way a wind turbine turns might not seem to matter

（635字精读必做篇）

If the hands of dial clocks swept over their faces the other way around, that would be the direction known as “clockwise”. And they would tell the hour just as faithfully. It is convenient to have all clock hands turn in the same direction, but it is an accident of history which direction that is. Similarly, it seems an arbitrary but efficient choice by wind-turbine makers that the blades of almost all of those devices turn clockwise. However, a study presented on May 4th to the General Assembly of the European Geosciences Union (held online, instead of in Vienna, as planned), suggests that in the northern hemisphere, where 96% of these turbines are found, universal clockwiseness may be bad.

For a single turbine it does indeed not matter. But turbines are usually planted in groups. If, in such a group, one turbine is behind another then it does matter, according to Antonia Englberger of the German Aerospace Centre, in Oberpfaffenhofen, and her colleagues. They have built a computer model which simulates the flow of air over a turbine turning in either direction, and then calculates the effect this has on a second turbine, downwind of the first. By day, the team conclude, there is no difference. But at night the power output of the downwind device may be up to 23% higher if its upwind colleague is turning anticlockwise.

The reason lies in the nocturnal behaviour of the bottom few hundred metres of the atmosphere, known as the boundary layer. By day, the sun’s rays heat the ground, which heats the nearby air, which rises in whorls of turbulence, resulting in a well-mixed boundary layer that behaves in the same way at all altitudes. The consequence, for a wind turbine, is that its rotor blades feel the same wind speed and direction whether they are at the top or the bottom of their rotation.

At night, however, the ground cools. The whorls therefore often go away and the boundary layer stops mixing. Friction with vegetation or buildings now means that air close to the ground moves more slowly than air higher up—an effect known as altitude-related wind shear. And the amount of shear, given the blade-span of modern turbines, is large enough for Earth’s rotation to come into play. This pushes moving air to the right in the northern hemisphere and to the left in the southern, a phenomenon called the Coriolis force. The faster the airflow, the larger the deviation. Thus wind shear begets wind veer, a gradual change in direction with height.

That matters for turbine pairs because the air that pushes against the blades of the upwind device, and thus gets them to rotate, say, clockwise, is itself deflected by those blades in the other direction. This turns it into a turbulent wake with a rotation (in this case) going anticlockwise. This anticlockwise rotation conflicts with the Coriolis-induced veering tendency of the undisturbed wind around the wake. And that hampers the wake’s ability to pick up energy from this surrounding, undisturbed wind and then go on to hit the second turbine with renewed vim.

In the case that the first turbine rotates anticlockwise, the wake will be clockwise, thus matching the northern-hemisphere wind veer. This lets it gain energy from the surrounding air to deliver to the next turbine—the opposite of what now happens. And in the southern hemisphere this all works the other way around, so conventional, clockwise turbines do best.

Retooling factories in light of Dr Englberger’s discovery, to make turbines run anticlockwise instead, would certainly be expensive. Whether the extra power that could be squeezed out of the wind by doing so would make that worthwhile would require a lot more investigation. Her result does, however, show neatly how even apparently arbitrary decisions can have unintended consequences.

Source: The Economist

【社会科学-科技】

Internet Cables Could Also Measure Quakes

（291字 1分49秒精听必做篇）

先做精听再核对原文哦~

[attach]250239[/attach]

In addition to giant crustaceans and creepy anglerfish, the deep oceans hide a vital piece of technology: the cables connecting almost every continent, island and archipelago to the Internet. But it seems those undersea cables can be used for more than just sending cute cat memes around the world.

“We can do a good job picking up earthquakes in offshore cables.”

Jonathan Ajo-Franklin is an applied geophysicist at Rice University and Lawrence Berkeley National Lab. He says that fiber-optic cables are like threads of glass—and there are impurities built in. So when you shoot lasers through the fibers, those impurities backscatter some of the light right back to the laser source.

“We make measurements of the change in the backscattered light over time, which gives you information on the stretch of the cable at each location."

His team took advantage of a brief maintenance period when a particular cable, off the coast of Monterey, California, was not being used for communication. The researchers studied the slight deformations in the cable and were able to sense a small earthquake, pinpoint unmapped faults in the seafloor and observe movements in the water column—all of which might be of interest to oceanographers.

Their work is in the journal Science.

Ajo-Franklin points out that seismometers are pretty sparse in the world’s oceans:

“It’s a big blank spot.”

So these cables could really come in handy. And unlike for this study, you wouldn’t even have to turn off the Internet to do it.

“We’re looking at ways of potentially using just a small section of the spectrum, so you can communicate at the same time you can do sensing on these kinds of cables.”

Which might bring more of the Earth’s deep rumblings online.

Source: Scientific American

【笔记格式要求】

精读笔记格式要求：

1.总结文章中心大意

2.总结分论点或每段段落大意

3.摘抄印象深刻或者觉得优美的句子

4.总结文章中的生词

5.记录阅读时间、总结时间、总时间

精听笔记格式要求：

1.逐句听写整篇文章

2.对照原文修改听写稿，标记出错原因

3.总结文章中心大意

4.总结精听过程中的生词

5.记录听写时间、总结时间、总时间

这里也给大家两点学习小建议哦~

精读：如遇到读不懂的复杂句，建议找出句子主干，分析句子成分，也可以尝试翻译句子来帮助理解~

精听：建议每句不要反复纠结听，如果听 5 遍都没听出来，那就跳过，等完成后再回听总结原因，时间宝贵，不要过于执着哦~

作者: 妥妥 时间: 2020-6-14 20:16

揽瓜阁俱乐部，自「language」一词谐音而来，是一个为帮助大家提升英语语言能力而建立的学习小团队。在这里，我们将定时发布涵盖各类话题的外刊语料，供大家练习精听、精读。同时还设置了严格的打卡机制，督促大家克服懒惰坚持学习。

同时我们也招募volunteer协助维护团队，确保学习活动顺利开展~大家一起营造积极向上的学习氛围~

想要提升英语能力的小伙伴，快快添加微信（theTOEFL）报名加入吧，让妥妥带你观尽天下新鲜事，览遍四海热议瓜～

如果你想加入，可以直接在本帖下完成你的学习笔记！如果想进入学习群聊，请直接联系妥妥。

作者: 龙驾马 时间: 2020-6-15 10:56
阅读笔记

1. 文章中心大意
风力发电机的叶片转动方向看似是一个无关紧要的问题。厂商们都设定成顺时针方向，一遍降低生产和维护成本。但最新的研究发现，在北半球，成批的风动机如果在夜间还是按照顺时针方向旋转，夜间地面降温产生的上升气流会降低发电效率。如果能都改成逆时针旋转，则输出功率可能会提高23%。这种在起初看似随意的决定，已经造成了不必要的浪费，而是否再投入资金去把北半球的风动机叶片改成逆时针方向，则成了另一个需要仔细研究的课题。

2.每段大意
第一段: 风力发电的主体设备——风动机，其叶片大都被制造商设定成了顺时针方向。这种统一的方向设置可以降低生产成本，而且看上去对发电效果没有影响。
第二段: 德国航空航天中心的专家，对成批的风动机进行研究后发现，虽然单个风动机的叶片转向对效果没有关系，但它们会影响其他周围的风动机。进而发现如果在夜间都设定为逆时针旋转，其输出功率可能会提高23%
第三段:在白天，由于阳光加热地面的大气使其上升，对风动机来说其叶片的顶部与底部的空气风向与风速是一样的。
第四段：而在夜间，由于地面姜文，接近地面的空气速度变慢，而上部空气速度快。出现了与海拔高度相关的风力切变。在北半球空气向右侧移动，南半球则向左侧移动。
第五段：这种风力切变会对风动机叶片产生影响，在北半球如果成群的风动机都呈顺时针转动叶片，其发电效率就会变低。
第六段：相反，北半球的风动机如果设置成逆时针来转动叶片，则发电效率将会提升。南半球则设置成顺时针为宜。
第七段：对于是否要将用在北半球的涡轮机都改成逆时针运行，还需要进行更多的调查。但通过这个案例，我们会发现随意的决策可能会产生意想不到的后果。

句子摘抄：

It is convenient to have all clock hands turn in the same direction, but it is an accident of history which direction that is.

The consequence, for a wind turbine, is that its rotor blades feel the same wind speed and direction whether they are at the top or the bottom of their rotation.

Friction with vegetation or buildings now means that air close to the ground moves more slowly than air higher up—an effect known as altitude-related wind shear.

Her result does, however, show neatly how even apparently arbitrary decisions can have unintended consequences.

生词摘抄:

turbine v.涡轮机
nocturnal a.夜间的
turbulence n.混乱，湍流
anticlockwise adv.逆时针地 a.逆时针的
deviation n.偏差，背离
hampers v.妨碍，束缚

时间：阅读12分钟总结20分钟总时间32分钟
[attach]250323[/attach][attach]250324[/attach][attach]250325[/attach][attach]250325[/attach]
错误原因

1 部分生词不熟悉
2 人名错
3 of 等介词还是会听成别的

中心大意

科学家们正在设法改进海底光缆使之能应对突发的诸如地震等事件

生词摘抄

crustacean n.甲壳类
archipelago n. 群岛
measurement n. 测量

听写时间 21分钟总结 18分钟总共39分钟

作者: yunjuan 时间: 2020-6-15 11:31
虫力大 day1 6.15

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day 1 打卡
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D1

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D1

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MJ-MJ 2020.6.15 Day1[attach]250285[/attach][attach]250286[/attach]

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DAY1

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Day 1

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Day1

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day1 DAKA

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第一天打卡

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DAY 1

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D1

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Day1
干掉他没商量

作者: wanglu1994143 时间: 2020-6-15 21:27
打卡

作者: 904 时间: 2020-6-15 21:34
Day 6.15

作者: 六元的小心心 时间: 2020-6-15 21:37
DAY1[attach]250309[/attach]

作者: Dovis 时间: 2020-6-15 21:41

揽瓜阁 Day 1

Dovis 2020 6 15

精读 Which way a wind turbine turns might not seem to matter

一文章总结

风力发电机的叶片转动方向都被设定成顺时针方向。但最新的研究发现，在北半球，批量风动机如果在夜间、按照顺时针方向旋转会降低发电效率。而反之则输出功率可能会提高23%。这种在起初看似随意的决定，已经造成了不必要的浪费。

二段落大意

和时钟一样，目前的风力发电机转动方向被设计为顺时针转动，而近期的调查显示，在北半球，96%的顺时针转动的风机会浪费能效。
虽然单个风机叶片顺时针或者逆时针没有关系，但风机通常是以风电机组形式建立。研究人员建模发现，夜间如果改用逆时针旋转，则其后面的风机效率会提升23%。
白天，由于阳光加热空气上升，对风电机来说叶片上下的风速和方向是一样的。
夜间温度降低，导致空气上下流动速度不一样；地球自转导致南北半球空气上下的风向也不一样。
以上现象会导致顺时针转动的叶片发电效率降低。
北半球的风动机如果被设计为逆时针旋转，会使得发电效率提升。相反地，南半球使用顺时针旋转会更好。
是否要将风机转动方向修改还需要更多的调查。但通过此次事件，一个随机的决策很可能造成意想不到的后果。

三生词摘录

clockwise 正转的；右旋的; 顺时针方向转动地；右旋地

nocturnal adj. 夜行的；夜出的；夜间发生的

whorl n. 【植】轮；【动】(螺狮等的)壳阶；螺旋部；(昆虫等的)毛轮

hampers 妨碍，束缚

Coriolis force 地球自转偏向力

beget v. 引发；成为…之父；导致

四句子摘抄

The consequence, for a wind turbine, is that its rotor blades feel the same wind speed and direction whether they are at the top or the bottom of their rotation.

五用时记录

阅读 5min 总结 19min 共计30min

作者: KLYnn 时间: 2020-6-15 21:41
来咯～

作者: Dovis 时间: 2020-6-15 21:43
听力部分

作者: 小阮 时间: 2020-6-15 21:46
[attach]250315[/attach]

作者: xxnmm 时间: 2020-6-15 21:47
很累也很酷！

作者: 嬛嬛浅笑梨涡 时间: 2020-6-15 21:50
Day1打卡

[attach]250317[/attach]

作者: 啊哒 时间: 2020-6-15 21:55
极限卡点

作者: NOIR123 时间: 2020-6-15 21:57
Day 1差点忘了上传，我来啦

作者: Alice0520 时间: 2020-6-15 21:58
day1

作者: ling0602 时间: 2020-6-15 21:58
DAY1 lexie

作者: llzzzzzy 时间: 2020-6-15 21:59
llzzzzzy 打卡day1

作者: Alice0520 时间: 2020-6-16 21:22
DAY 1

作者: 木辛青 时间: 2020-6-16 21:46
补昨天没加上的时间和大意

作者: xxnmm 时间: 2020-6-16 22:48
补Day听力生词和大意！

作者: Rafe 时间: 2020-8-25 11:11
文章大意：钟表指针的顺时针旋转能告诉我们准确的时间，这看上去不错。于是风力发电机制造商就随意的决定了风力发电叶片也顺时针旋转这一设计。但是，并不是所有的风力发电机叶片顺时针旋转就是好的。研究发现，北半球风力发电机的叶片逆时针旋转的话能得到更高的发点能力。但是，相比起改善后得到的额外的发点效能，改变这些需要的投资是巨大的。所以，表面上看似随意的决定可能会带来意想不到的结果。

第一段：几乎所有的风力发电机都是顺时针旋转。然而研究表明，统一性的顺时针旋转叶片并非好事。
第二段：研究表明，在夜晚，风力发电机组中，如果前排的机组逆时针旋转的话，后排的机组的发电效能能提高23%。
第三段：原因在于地表大气的活动。在白天，由于太阳会对地表以及周围的空气加热，把地表附近的空气很好的混合。
于是叶片顶端和底端接受到的相同性质的风。所以在白天没有什么差别。
第四段：但是到了晚上，对流消失，边界层停止对流。Coriolis力的产生使气流在垂直方向上改变。
第五段：叶片产生的尾流会影响Coriolis力，从而影响下一个叶片的工作性能。
第六段：逆时针旋转的叶片的尾流是顺时针的，能更容易的把尾流的能量传递给下一个叶片。在南半球，则完全相反。所以，传统地，顺时针叶片工作的更好。
第七段：为了改变现在的叶片的选装方向是成本很高的。是否值得这样做需要更多的调查。一些看上去随意的决定，会得到意想不到的结果。
听力：

文章大意：海底除了奇怪的生物，还有海底光缆。我们可以利用这些光缆来观测地震。光纤中含有杂质，通过观察这些杂质反射回来的激光来观察光缆的形变，从而观察地震。海底地震仪在世界上是一块空白领域。在观察电缆形变的时候不需要切断它，所以不影响普通用户的使用。

crustaceans 甲壳类

creepy 诡异的

archipelago 群岛，列岛

impurities 杂质

stretch 拉伸，延展

backscatter 反射

seismometers 地震仪

deformations 形变

rumblings 隆隆声

听写时间： 1小时12分

总结时间：5分钟

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