首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Today in mind-bendingly cool stuff that nanoparticles(纳米粒子)can do: A team of researchers at Rice University in Texas has demonst
Today in mind-bendingly cool stuff that nanoparticles(纳米粒子)can do: A team of researchers at Rice University in Texas has demonst
admin
2015-08-26
22
问题
Today in mind-bendingly cool stuff that nanoparticles(纳米粒子)can do: A team of researchers at Rice University in Texas has demonstrated a mechanism by which they can create steam in just seconds by focusing sunlight on a mixture of water and nanoparticles. This isn’t just some artificial means of lowering boiling point either: this solar powered "boiler" can produce steam before the water even gets warm to the touch, without ever bringing the aggregate water to a boil.
Right now this research is very much still in the lab, and the researchers aren’t sure exactly how far they can push it. But it doesn’t take much to imagine the possibilities for a steam generator that runs solely on water and sunlight.
The technology works by mixing a small amount of either carbon or gold-coated silicon dioxide(二氧化硅)nanoparticles, each just one-tenth the diameter of a single human hair, with water in a glass vessel. Their small diameters—smaller than the wavelength of visible light—means that they can absorb most of a light wave’s energy rather than scattering it. So when sunlight is focused on the vessel with a lens, the particles quickly become quite hot—hot enough to vaporize(蒸发)the water directly surrounding it.
This creates a bubble of steam that envelopes the nanoparticle, which is now insulated from the cooler liquid water by the steam, which allows it to grow hotter still, vaporizing more of the water immediately around it. At some point the nanoparticle and its steam envelope become large enough to grow buoyant, at which point the whole steam bubble— particle and all—floats to the surface. The steam is released into the air, the particle falls back into the cooler water and sinks back down until it begins to absorb sunlight and heat again, at which point the process starts all over.
Multiply that by the number of nanoparticles in the mixture, and you have something of a simulated boil, but one that doesn’t require the entire pot of water to reach boiling point before the first steam bubbles head to the surface. You can think of it as a way of micromanaging the boiling process, specifically heating some parts of the water(where it touches the nanoparticles)while leaving the rest of the water cool. And the particles themselves are completely durable—they keep absorbing, heating, cooling, and absorbing again, with no need to replace them.
Pretty nuts, no? It spells an interesting future for solar power in general, but more specifically it’s easy to see how a cheap and abundant source of steam, even in low specific volumes, could be used to do anything from generate electricity and heat to lower the energy intensive nature of certain processes like water desalinization(脱盐). As the WaPo points out, the last time someone came up with a cheap and easy way to generate and harness abundant steam it completely changed the world. So there’s that.
As to micromanaging the boiling process, the author has described all the following EXCEPT______.
选项
A、the conditions
B、the method
C、the principle
D、the materials
答案
A
解析
细节题。第三至五段描述了通过太阳光和纳米粒子产生蒸汽的“微处理沸腾过程的方式”的工作原理、流程、所需材料,但并未提及该机制起作用的具体环境,故选[A]。
转载请注明原文地址:https://kaotiyun.com/show/I3XK777K
0
专业英语四级
相关试题推荐
Themeditationbeginsinawaythatsurprisesmanypeople,becauseitstartsbycultivatinglovingfeelingtowardyourself.Yet
Onenight,Iwasonthephonewithmysister-in-law,Dawn.Ihadcalledhertoletherknowourhusbandswouldhavetoworkvery
Foralongtime,researchershavetriedtonaildownjustwhatshapesus--orwhat,atleast,shapesusmost.Andovertheyears,
It’sgettingratherlate.It’stimewe______.
"Congratulations,Mr.Cooper,it’sagirl."Fatherhoodisgoingtohaveadifferentmeaningand【31】adifferentresponsefro
"Congratulations,Mr.Cooper,it’sagirl."Fatherhoodisgoingtohaveadifferentmeaningand【31】adifferentresponsefro
"Congratulations,Mr.Cooper,it’sagirl."Fatherhoodisgoingtohaveadifferentmeaningand【31】adifferentresponsefro
Onceuponatime,youbelievedinthetoothfairy.Youcountedonthestabilityofhousingpricesanddependedonbankerstobe,
Themembersinthetestingteamwerequite_______andcouldchangetheirscheduleuponrequest.
ThenewLenovolaptopwiththebutterflykeyboardandthebuilt-inFAXmodemisapretty______machine.
随机试题
下列标准化法的叙述中,错误的是
稳定型心绞痛的发病机制是
心力衰竭患者长期服用噻嗪类利尿剂,最容易发生的不良反应是()。
根据《生产安全事故报告和调查处理条例》,单位负责人接到事故报告后,应当于()小时内向事故发生地县级以上人民政府安全生产监督管理部门和负有安全生产监督管理职责的有关部门报告。
甲公司发行1000万股普通股股票,每股面值1元,每股公允价值5元,作为合并对价取得乙公司80%的股权,能够对乙公司实施控制。支付券商佣金等20万元,合并各方在交易前均无关联方关系。购买日乙公司可辨认资产公允价值为5000万元,账面价值为4500万元,可辨认
用于估计过程平均不合格率的批数,一般不应少于()批。
别墅:建筑
引起动机的外在条件是
()即使在客观上造成了危害结果,也不是刑法意义上的行为。
设随机变量.向量组α1,α2线性无关,则Xα1一α2,一α1+Xα2线性相关的概率为().
最新回复
(
0
)