Alternative energy sources

替代能源

How to wring power from the night air

如何从夜晚的空气中汲取能量

Mimic the way that lightning happens

模仿闪电产生的方式

Aug 3rd 2019 | MONTREAL

SOLAR POWER is all very well, but it is available only during daylight hours. If something similarly environmentally friendly could be drawn on during the hours of darkness, that would be a great convenience. Colin Price, an atmospheric scientist at Tel Aviv University, in Israel, wonders if he might have stumbled across such a thing. As he told a meeting of the International Union of Geodesy and Geophysics, held in Montreal in July, it may be possible to extract electricity directly from damp air—specifically, from air of the sort of dampness (above 60% relative humidity) found after sundown, as the atmosphere cools and its ability to hold water vapour diminishes.

太阳能已经很棒了，但是只能在白天使用。如果同样环保的东西也能在黑暗中使用，这将会带来极大的便捷。以色列特拉维夫大学的大气科学家科林·普莱斯(Colin Price)想知道他能否有机遇碰到这种物质。正如他在/国际大地测量学和地球物理学联合会/的于7月在蒙特利尔举行的会议上所声明的那样,人们也许可以直接从潮湿的空气中提取电力——尤其是在空气的湿度(相对湿度60%以上)的情况下，而这情况被发现在日落之后,此时大气开始降温，同时自身蓄存水蒸气的能力开始下降。

词汇

Vapour/蒸气；潮气；雾气

Dr Price’s apparatus is a pair of concentric metal cylinders. The outer cylinder is earthed while the inner one is not, creating a capacitor. Passing suitably moist air through the inner cylinder causes that cylinder to accumulate electric charge, thus creating a potential difference between the cylinders which could be harnessed to drive a current through an external circuit.

普莱斯博士的仪器是一对同心的金属圆筒。外筒接地而内筒不接地，形成电容器。将适当的潮湿空气通过内筒，使筒体积聚电荷，从而在筒体之间产生电位差，可以利用电位差驱动电流通过外部电路。

词汇

Apparatus/装置，设备；仪器；器官

In effect, and at an extremely small scale (so far, a maximum of just under a volt), Dr Price thinks he has tamed lightning—which is surprising, in a way, because no one truly knows how lightning works. As Dr Price himself observes, “Thunderstorms produce electricity...But if they didn’t know it, theoreticians would never predict lightning to exist on Earth. They might predict clouds forming, but not a 10km-high spark, building in half an hour out of nothing.”

实际上，在一个非常小的规模内(到目前为止，最大电压仅略低于1伏)，普莱斯博士认为他已经驯服了闪电——这在某种程度上是令人惊讶的，因为没有人真正知道闪电是如何工作的。正如普莱斯博士自己所观察到的，“雷暴产生电力……但如果他们对机理不了解，理论家就永远无法预测地球上的闪电。他们可能预测云的形成，但难以对10千米高，在半小时内从无到有地形成的火花进行预测，。”

词汇

Theoretician/理论家，精通于理论的人

One thing that is known about lightning, however, is that it requires water to be present in all three states of matter: solid, liquid and vapour. Dr Price suspects that in his experiment the surface of the inner cylinder is taking on the role played in a thunderhead by water’s solid phase, ice. His comparison of different metals’ effectiveness in that role—zinc is best, copper is useless—may help elucidate the details of the process, not only in his putative generator, but also in a natural thunderstorm.

然而，关于闪电，我们知道的一件事是，它需要水存在于物质的所有三种状态:固态、液态和气态。普莱斯博士怀疑，在他的实验中，内圆筒的表面正扮演着由水的固态——冰，在雷雨云中所扮演的角色。他比较了不同金属在这方面的效果——锌是最好的，铜是无效的——这可能有助于阐明这个过程的细节，不仅在他假定的发电机中，而且在自然雷暴中也是如此。

词汇

Elucidate/阐明；说明

Putative/推定的，假定的

His hypothesis is that things start when water droplets condense out of the humid air and onto the metal surface. Though water consists mostly of molecules of hydrogen and oxygen (H2O), at any given time a few of those molecules will have broken up spontaneously into positively charged hydrogen ions (H+) and negatively charged hydroxyl ions (OH-). These two types of ion will then move through a droplet at different rates, depending on the nature of the surface to which the droplet is attached, separating the positive and negative charges within that droplet. This charge separation will, in turn, induce a charge on the surface of the cylinder, and thus a potential difference in the capacitor.

他的假设是，当水滴从潮湿的空气中凝结到金属表面时，反应就开始了。虽然水主要由氢和氧(H2O)分子组成，但在任何时候，其中的一些分子都会自发地分裂成带正电荷的氢离子(H+)和带负电荷的羟基离子(OH-)。这两种离子会以不同的速度穿过液滴，这取决于液滴附着的表面的性质【nature在这有性质的意思，“极性”这个词有专门的表达（polarity ）】，将液滴中的正电荷和负电荷分开。这种电荷分离反过来会在圆柱体表面产生电荷，从而在电容器中产生电位差。

词汇

Droplet/小滴，液滴

Condense/浓缩；凝结

Spontaneously/自发地；自然地；不由自主地

Having established the principle, the question Dr Price now faces is whether he can scale things up to a useful degree. This will involve tinkering with cylinders made from various combinations of metals and metal alloys, and also playing with the configurations of the cylinders with respect to one another. That there actually is, out there, a combination of substance and geometry which will yield useful amounts of electricity is, perhaps, a long shot. But, given the power of lightning itself, it certainly seems worth looking into.

在确立了这一原理之后，普莱斯博士现在面临的问题是，他能否把反应扩大到有用的规模。这将涉及到熔补由各种金属和金属合金组合而成的圆柱体，还涉及到对圆柱体相互之间的结构进行调整。事实上，物质和几何层面的结合将产生大量有用的电能；也许，是一个不太可能实现的目标。但是，考虑到闪电本身的力量，它确实值得一探究竟。

词汇

Tinkering/铸补，熔补

Configuration/配置；结构；外形

Geometry/几何学

a long shot/不大会成功的尝试