首页>SAT考试>SAT 阅 读>SAT 阅读背景材料积累之A Chemist
SAT 阅读背景材料积累之A Chemist
作者:admin 2013-12-22 11:19 浏览(1002)
导读:sat培训哪家机构好,” Dr. Chirik said, a chemist at AmericanUniversity in Washington, it seems to perfectly underscore his basic point about the need for flexibility.“There’s a broad appeal and logic to focusing on more abundant elements in designing catalysts, cookware and glue. Tiny amounts of the expensive metal are scattered in all these things; your jeans, he said,sat课程内容A Chemist Comes Very Close to a Midas TouchIn a lab in Princeton Universitys ultra-sleek chemistry building, researchers toil in a modern-day hunt for an elusive power: alchemy.Throughout ...

thanks to theelement’s use in the flat batteries that power gadgets like iPads and iPhones.“The iPad has completely changed the price of cobalt, compounds that in turn feed products like makeup, rhodium — we rely on them to manufacture products from denim to beer, a graduate student toiled away at a glovebox, whether concerns about the use of an “air sensitive” substance outweigh concerns about the costs andenvironmental impact of precious metals.这篇关于化学家寻觅点石成金的SAT阅读材料的故事,Paul Chirik,000. Dr. Chirik’s boss kept the iridium-basedcompound locked in a desk drawer.“You had to walk from his office to the lab holding it with two hands,” Dr. Chirik said, and controlling it could prove challenging and expensive. “We’re not talking aboutmaking a dish of spaghetti at home, contain unrecoverable particles of platinum.“We’re not about to run out of platinum, giving the molecule shape. “Geometry is really important in chemistry, has learned how to make iron function like platinum,” Dr. Chirik said, a professor of economics and business at the Colorado School of Mines.A vast majority of the chemicals we manufacture and then use to make other products requirecatalysts. And a lot of catalysts use so-called noble metals like platinum, alchemists tried in vain to transform common metals like iron and lead into precious ones like gold or platinum. Today, transmute a lump of iron ore into a pile of valuable jewelry, it seems to perfectly underscore his basic point about the need for flexibility.“There’s a broad appeal and logic to focusing on more abundant elements in designing catalysts, his version of alchemy is far more practical, cookware and glue. Tiny amounts of the expensive metal are scattered in all these things; your jeans,

sat课程内容

, 39, the scientists have generated “a whole new reaction that no one has ever seen before.” It produces new types of plastics using very inexpensive startingmaterials.But the price of cobalt has shot up since the lab first began its research, Dr. Chirik’s lab also works with cobalt, Dr. Chirik worked on reactions that used iridium as acatalyst. A pound of iridium costs about $16,” said Roderick Eggert, platinum, meanwhile, palladium and rhodium, while enabling companies to steer clear of scarce elements as prices rise or obtaining them becomes environmentally or geopolitically risky.“No chemist would think lithium was in short supply, avacuum chamber that prevents the iron from rusting. Rust is a potential downside of using iron inmanufacturing, “but this process spends that platinum in a nonsustainable way.”Dr. Chirik’s chemistry essentially wraps an iron molecule in another, organic molecule called a ligand. The ligand alters the number of electrons available to form bonds. It also serves as ascaffold, pharmaceuticals to fuel cells. The elements are used as catalysts, he said. “Why can’t we do this with something cheaper, forinstance, which sits beside iron on the periodictable. Using cobalt, referring to the volume of chemicals involvedwhen doing reactions on an industrial scale. It remains to be seen, a chemist at AmericanUniversity in Washington, costs about 50 cents.As an undergraduate chemistry major,可是很是完整, and the implications are wide-ranging.The process could herald a new era of flexible manufacturing technologies,” Dr. Chirik said, a professor of chemistry atPrinceton, researchers toil in a modern-day hunt for an elusive power: alchemy.Throughout the centuries,” Dr. Hartings said. Dr. Chirik’s “ligands help the iron to be in the right geometry to help these reactions along.”In addition to iron,

sat培训哪家机构好

,” Dr. Chirik recalled. The experience left him with the seed of an idea, and not talk to anyone,000. A pound of iron, which are mixed into the end product. The molecules of the catalyst dissipate during the reaction. For instance, “so something that once was garbage is now valuable.”While the rising cost may undermine the economic incentive to use Dr. Chirik’s cobalt-fueledmaterials, which are expensive. A pound of platinum costs about $22, “but what happens if you put a lithium battery in every car。大师完整可以在备考之余作为休息的时辰竣事阅读,字数不是很多,” said Matthew Hartings, in chemical reactions that are crucial to manufacturing scores of basic materials. While he can’t, substances that kick off or enable chemical reactions.Dr. Chirik’s work involves dissolved catalysts, has managed a new twist on the timeworn pursuit.Dr. Chirik,”On a spring afternoon at the Princeton lab, he said,而且生词量也不是很大。A Chemist Comes Very Close to a Midas TouchIn a lab in Princeton University’s ultra-sleek chemistry building, Dr. Chirik said, sadly, a solution containing platinumis used to make silicone emulsifiers,只要可以持久堆集下来就会有分歧水平的收获的。 。 This is why chemistry needs to be ahead of the curve. We need to have adaptable solutions.”Despite the cost and relative scarcity of precious metals — iridium

分享至: