随着PTE考生对PTE口语和PTE听力的重视，大家口语和听力的分数得到极大提高，但是PTE阅读渐渐成为考生们新的难题。墨尔本悉尼文波PTE特别为PTE考生们挑选了适合练习PTE阅读的文章，主题，内容，长度都与PTE阅读题中的文章相似。激活学过的词汇，更新新的词汇，提高阅读速度，全面提升自己的阅读能力。
Chemist Daniel Nocera of Harvard University and his team joined forces with synthetic biologist Pamela Silver of Harvard Medical School and her team to craft a kind of living battery, which they call a bionic leaf for its melding of biology and technology. The device uses solar electricity from a photovoltaic panel to power the chemistry that splits water into oxygen and hydrogen, then adds pre-starved microbes to feed on the hydrogen and convert CO2 in the air into alcohol fuels. The team’s first artificial photosynthesis device appeared in 2015—pumping out 216 milligrams of alcohol fuel per liter of water—but the nickel-molybdenum-zinc catalyst that made its water-splitting chemistry possible had the unfortunate side effect of poisoning the microbes.
So the team set out in search of a better catalyst, one that would play well with living organisms while effectively splitting water. As the teamreports in Science on June 2, they found it in an alloy of cobalt and phosphorus, an amalgam already in use as an anticorrosion coating for plastic and metal parts found in everything from faucets to circuit boards. With a little charge, this new catalyst can assemble itself out of a solution of regular water, cobalt and phosphate—and phosphate in water actually is good for living things like the Ralstonia eutrophabacteria that make up the back half of the bionic leaf. Run an electric current from a photovoltaic device through this solution at a high enough voltage and it splits water. That voltage is also higher than what is needed to induce the cobalt to precipitate out of the solution and form the cobalt phosphide catalyst, which means when the bionic leaf is running there are always enough electrons around to induce the catalyst’s formation—and therefore no excess metal left to poison the microbes or bring the bionic leaf’s water-splitting to a halt. “The catalyst can never die as it’s functioning,” Nocera says, noting that the new artificial leaf has been able to run for up to 16 days at a stretch.
synthetic 综合的
bionic 仿生学的
hydrogen 氢
catalyst 催化剂
organism 有机体
alloy 合金
faucet 旋塞
cobalt 钴
precipitate 沉淀
