使氢化反应过程更环保-凯发k8官网

使氢化反应过程更环保
文章来源:未知 文章作者:enread 发布时间:2013-06-29 08:59 字体: [ ] 
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researchers from mcgill university, riken (the institute of physical and chemical research, wako, japan) and the institute for 1 science (okazaki, japan) have discovered a way to make the widely used chemical process of hydrogenation more environmentally friendly -- and less expensive. hydrogenation is a chemical process used in a wide range of industrial applications, from food products, such as margarine(人造黄油), to petrochemicals and 3. the process typically involves the use of heavy metals, such as palladium or 4, to 5 the chemical reaction. while these metals are very efficient 7, they are also non-renewable, 8, and subject to sharp price 9 on international markets.
 
because these metals are also 10, even in small quantities, they also raise environmental and safety concerns. 2 companies, for example, must use expensive purification methods to limit 11 levels of these elements in pharmaceutical products. iron, by contrast, is both naturally abundant and far less toxic than heavy metals.
 
previous work by other researchers has shown that iron nanoparticles -- tiny pieces of 12 iron -- can be used to 13 the hydrogenation reaction. iron, however, has a well-known drawback: it 14 in the presence of oxygen or water. when 15, iron nanoparticles stop 16 as hydrogenation catalysts. this problem, which occurs with so much as trace quantities of water, has prevented iron nanoparticles from being used in industry.
 
in research published today in the journal green chemistry, scientists from mcgill, riken, and the institute for molecular science report that they have found a way to overcome this limitation, making iron an active 6 in water-ethanol mixtures containing up to 90% water.
 
the key to this new method is to produce the particles directly inside a polymer matrix, composed of amphiphilic polymers based on polystyrene and polyethylene glycol(聚乙二醇). the polymer acts as a wrapping film that protects the iron surface from 17 in the presence of water, while allowing the reactants to reach the water and react.
 
this innovation enabled the researchers to use iron nanoparticles as catalyst in a flow system, raising the possibility that iron could be used to replace platinum-series metals for hydrogenation under industrial conditions.
 
"our research is now focused on achieving a better understanding of how the polymers are protecting the surface of the iron from water, while at the same time allowing the iron to interact with the substrate," says audrey moores, an assistant professor of chemistry at mcgill and co-corresponding author of the paper.
 
the results stem from an 18 19 between mcgill and riken, one of japan's largest scientific research organizations, in the fields of nanotechnology and green chemistry. lead author reuben hudson, a doctoral student at mcgill, worked on the project at the riken center for sustainable resource science and at the institute for molecular science in japan. co-authors of the paper are prof. chao-jun li of mcgill, dr. go hamasaka and dr. takao osako of the institute for molecular science, dr. yoichi m.a. yamada of riken and prof. yasuhiro uozumi of riken and the institute for molecular science.


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1 me9xh     
adj.分子的;克分子的
参考例句:
  • the research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • for the pressure to become zero, molecular bombardment must cease.当压强趋近于零时,分子的碰撞就停止了。
2 f30zr     
adj.药学的,药物的;药用的,药剂师的
参考例句:
  • she has donated money to establish a pharmaceutical laboratory.她捐款成立了一个药剂实验室。
  • we are engaged in a legal tussle with a large pharmaceutical company.我们正同一家大制药公司闹法律纠纷。
3 be065c8a4af3a2d925d11969faac34cf     
n.医药品;药物( pharmaceutical的名词复数 )
参考例句:
  • the development of new pharmaceuticals 新药的开发
  • the companies are pouring trillions of yen into biotechnology research,especially for pharmaceuticals and new seeds. 这些公司将大量资金投入生物工艺学研究,尤其是药品和新种子方面。 来自《简明英汉词典》
4 cuoyc     
n.白金
参考例句:
  • i'll give her a platinum ring.我打算送给她一枚白金戒指。
  • platinum exceeds gold in value.白金的价值高于黄金。
5 btiyv     
v.催化
参考例句:
  • they are highly specific for the reactions that they catalyze.它们对被它们催化的反应有很强的专一性。
  • they are highly specific for the reactions that they catalyze.它们对被它们催化的反应有很强的专一性。
6 vovzu     
n.催化剂,造成变化的人或事
参考例句:
  • a catalyst is a substance which speeds up a chemical reaction.催化剂是一种能加速化学反应的物质。
  • the workers'demand for better conditions was a catalyst for social change.工人们要求改善工作条件促进了社会变革。
7 677fdea123458fc2ff92eb84d07254e9     
n.催化剂( catalyst的名词复数 );触媒;促进因素;有感染力的人
参考例句:
  • the first catalytic converters were called conventional oxidation catalysts. 最初的转化器叫做常规氧化催化器。 来自辞典例句
  • many processes that are essential to the chemical industry use heterogeneous catalysts. 很多重要的化学工业过程就是使用多相催化剂的。 来自辞典例句
8 7zxxh     
adj.昂贵的,价值高的,豪华的
参考例句:
  • it must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
  • this dictionary is very useful,only it is a bit costly.这本词典很有用,左不过贵了些。
9 5ffd9bfff797526ec241b97cfb872d61     
波动,涨落,起伏( fluctuation的名词复数 )
参考例句:
  • he showed the price fluctuations in a statistical table. 他用统计表显示价格的波动。
  • there were so many unpredictable fluctuations on the stock exchange. 股票市场瞬息万变。
10 inswc     
adj.有毒的,因中毒引起的
参考例句:
  • the factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
  • there is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。
11 swcxl     
adj.复播复映追加时间;存留下来的,剩余的
参考例句:
  • there are still a few residual problems with the computer program.电脑程序还有一些残留问题。
  • the resulting residual chromatism is known as secondary spectrum.所得到的剩余色差叫做二次光谱。
12 lcuxo     
adj.金属的;金属制的;含金属的;产金属的;像金属的
参考例句:
  • a sharp metallic note coming from the outside frightened me.外面传来尖锐铿锵的声音吓了我一跳。
  • he picked up a metallic ring last night.昨夜他捡了一个金属戒指。
13 uj2y0     
vt.使活动起来,使开始起作用
参考例句:
  • we must activate the youth to study.我们要激励青年去学习。
  • these push buttons can activate the elevator.这些按钮能启动电梯。
14 27b9b19980c5303e65d11a6f9f07e096     
n.铁锈( rust的名词复数 );(植物的)锈病,锈菌v.(使)生锈( rust的第三人称单数 )
参考例句:
  • copper nails are better than iron nails because the iron rusts. 铜钉比铁钉好,因为铁会生锈。 来自辞典例句
  • the axenic culture of rusts has been achieved on various defined media. 在各种规定的培养基上可得到锈菌的单体纯净培养物。 来自辞典例句
15 79e453270dbdbb2c5fc11d284e95ff6e     
v.(使)生锈( rust的过去式和过去分词 )
参考例句:
  • i can't get these screws out; they've rusted in. 我无法取出这些螺丝,它们都锈住了。 来自《现代汉英综合大词典》
  • my bike has rusted and needs oil. 我的自行车生锈了,需要上油。 来自《简明英汉词典》
16 czrzoc     
n.演戏,行为,假装;adj.代理的,临时的,演出用的
参考例句:
  • ignore her,she's just acting.别理她,她只是假装的。
  • during the seventies,her acting career was in eclipse.在七十年代,她的表演生涯黯然失色。
17 58458e5caedcd1cfd059f818dae47166     
n.生锈v.(使)生锈( rust的现在分词 )
参考例句:
  • there was an old rusting bolt on the door. 门上有一个生锈的旧门闩。 来自辞典例句
  • zinc can be used to cover other metals to stop them rusting. 锌可用来涂在其他金属表面以防锈。 来自辞典例句
18 6rvzt     
adj.进行中的,前进的
参考例句:
  • the problem is ongoing.这个问题尚未解决。
  • the issues raised in the report relate directly to age concern's ongoing work in this area.报告中提出的问题与“关心老人”组织在这方面正在做的工作有直接的关系。
19 bw7yd     
n.合作,协作;勾结
参考例句:
  • the two companies are working in close collaboration each other.这两家公司密切合作。
  • he was shot for collaboration with the enemy.他因通敌而被枪毙了。
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