C
The world’s first plastic magnet (磁性) to work at room temperature has passed the elementary test of magnetism. Its creators at the University of Durham in the UK have used it to pick iron filings (铁屑) from a laboratory bench.
In 2001, chemists from the University of Nebraska-Lincoln claimed to have created the world’s first plastic magnet, but it only worked below 10 Kelvin (开氏温度). Other researchers have made plastic magnets, but generally they only function at extremely low temperatures, or their magnetism at room temperature is too weak to be business use.
So the Durham team can claim to have made the first plastic magnet that could be used in everyday products. One of the most likely applications is in the magnetic coating of computer hard discs, which could lead to a new generation of high-capacity discs.
Jerry Torrance, a material scientist who is an adviser to some of the world’s largest electronics and engineering companies, including IBM, describes the work as “a great scientific breakthrough”. However, he says that practical applications are probably still a long way off.
At first the new polymer (聚合物) showed little sign of magnetism, and after three months the researchers had reached the point where they felt that trying to induce (诱发) magnetism in this polymer was a waste of time. “Just as we were about to give up and try a different way, we decided to check the samples for a last time,” says Sean Giblin.
It was a fortunate decision, because over the months the original polymer had developed magnetic characteristics. Further groups of polymer proved its magnetism and ruled out the possibility that the magnetism had been caused by pollution. In addition, X-ray diffraction data (衍射数据) showed an increase in the straight line of the polymer chains over three months, which probably accounts for the increase in magnetism.
Although the polymer’s magnetism is weak compared with metal magnets, the researchers are confident that they can improve it. And in addition to computer hard discs, the team thinks that plastic magnets could have important medical applications because organic magnetic materials are less likely to be rejected by the body.
64. The plastic magnets made by the chemists from University of Nebraska-Lincoln and other researchers couldn’t be used in everyday products because .
A. they didn’t pass the elementary test of magnetism
B. they couldn’t pick up iron filings from a laboratory bench
C. they wouldn’t work at room temperature
D. they could only be used at high temperature
65. The increase in magnetism over the months is probably caused by .
A. checking the samples B. a wise decision
C. pollution
D. the increase in the straight line of the polymer chains
66. The plastic magnets could be used .
A. to compare with the metal magnets
B. to coat computer hard discs
C. to produce medicine
D. to lower the temperature
67. What would be the best title for the passage?
A. The Birth of Practical Plastic Magnet
B. The World’s First Plastic Magnet
C. A Fortunate Decision
D. The Applications of Plastic Magnets