One type of polymer nanocomposite is currently being used in high-performance tennis balls for their _____.
A.barrier property
B.thermal property
C.electrical property
D.mechanical property
- · 有5位网友选择 B,占比62.5%
- · 有2位网友选择 A,占比25%
- · 有1位网友选择 D,占比12.5%
A.barrier property
B.thermal property
C.electrical property
D.mechanical property
A.Amorphous
B.Ceramic
C.Polymer
D.Crystalline
A、the degree of crystallinity of a polymer depends on the rate of cooling during solidification
B、the chains are more closely packed together for the crystalline structure.
C、the degree of crystallinity of a polymer depends on the chain configuration.
D、None the above
A.copolymer
B.heteropolymer
C.homopolymer
D.SBS
A.Amorphous
B.Ceramic
C.Polymer
D.Crystalline
A、The structure of repeating unit is not the same as that of the monomer.
B、The structural unit of polymer chain is always the same as its repeating unit.
C、In some cases, the structure of repeating unit is same as that of structural unit.
D、In some cases, the repeating unit consists of one or two structural units.
Sugar Power for Cell Phones
Using enzymes commonly found in living cells, a new type of fuel cell produces small amounts of electricity from sugar. If the technology is able to succeed in mass production, you may some day share your sweet drinks with your cell phone.
In fuel cells, chemical reactions generate electrical currents. The process usually relies on precious metals, such as platinum. In living cells, enzymes perform. a similar job, breaking down sugars to obtain electrons and produce energy.
When researchers previously used enzymes in fuel cells, they had trouble keeping them active, says Shelley D. Minteer of St Louis University. Whereas biological cells continually produce fresh enzymes, there's no mechanism in fuel ceils to replace enzymes as they quickly degrade.
Minteer and Tamara Klotzbach, also of St Louis University, have now developed polymers that wrap around an enzyme and preserve it in a microscopic pocket. "We tailor these pockets to provide the ideal microenvironment" for the enzyme, Minteer says. The polymers keep the enzyme active for months instead of days.
In the new fuel cell, tiny polymer bags of enzyme are embedded in a membrane that coats one of the electrodes. When glucose from a sugary liquid gets into a pocket, the enzyme oxidizes it, releasing electrons and protons. The electrons cross the membrane and enter u wire through Which they travel to the other electrode, where they react with oxygen in the atmosphere to produce water. The flow of electrons through the wire constitutes an electrical current that can generate power.
So far, the new fuel cells don't produce much power, but the fact that they work at all is exciting, says Paul Kenis, a chemical engineer at the University of Illinois at Urbana-Champaign. "Just getting it to work," Kenis says, "is a major accomplishment."
Sugar-eating fuel cells could be an efficient way to make electricity. Sugar is easy to find. And the new fuel cells that mn on it are biodegradable,, so the technology wouldn't hart the environment. The scientists are now trying to use different enzymes that will get more power from sugar. They predict that popular products may be using the new technology in as little as 3 years.
According to the first paragraph, when can we share our sweet drinks with our cell phones?
A.When enzymes can be commonly found in living cells.
B.When the technology of producing a new type of fuel cell appears.
C.When the technology of a new type of fuel cell is suitable for mass production.
D.When the technology of mass producing cell phones appears.
请根据短文的内容,回答题。
Sugar Power for Cell Phones
Using enzymes commonly found in living cells, a new type of fuel cell produces small amounts of electricity from sugar. If the technology is able to succeed in mass production, you may some day share your sweet drinks with your cell phone.<br>
In fuel cells, chemical reactions generate electrical currents. The process usually relies on precious metals, such as platinum. In living cells, enzymes perform. a similar job, breaking down sugars to obtain electrons and produce energy.<br>
When researchers previously used enzymes in fuel cells, they had trouble keeping them active,says Shelley D. Minteer of St LouisUniversity. Whereas biological cells continually produce fresh enzymes, there&39;s no mechanism in fuel cells to replace enzymes as they quickly degrade.<br>
Minteer and Tamara Klotzbach, also of St LouisUniversity, have now developed polymers that wrap around an enzyme and preserve it in a microscopic pocket. "We tailor these pockets to provide the ideal microenvironment for the enzyme," Minteer says. The polymers keep the enzyme active for months instead of days.<br>
In the new fuel cell, tiny polymer bags of enzyme are embedded in a membrane that coats one of the electrodes. When glucose from a sugary liquid gets into a pocket, the enzyme oxidizes it, releasing electrons and protons. The electrons cross the membrane and enter a wire through which they travel to the other electrode, where they react with oxygen in the atmosphere to produce water. The flow of electrons through the wire constitutes an electrical current that can generate power.<br>
So far, the new fuel cells don&39;t produce much power, but the fact that they work at all is exciting, says Paul Kenis, a chemical engineer at the University of Illinois at Urhana-Champaign.<br>
"Just getting it to work," Kenis says, "is a major accomplishment."<br>
Sugar-eating fuel cells could be an efficient way to make electricity. Sugar is easy to find. And the new fuel cells that run on it are biodegradable, so the technology wouldn&39;t hurt the environment.<br>
The scientists are now trying to use different enzymes that will get more power from sugar. They predict that popular products may be using the new technology in as little as 3 years.<
According to the first paragraph, when can we share our sweet drinks with our cell phones? 查看材料
A.When enzymes can be commonly found in living cells
B.When the technology of producing a new type of fuel cell appears
C.When the technology of a new type of fuel cell is suitable for mass production
D.When the technology of mass producing cell phones appears
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