Every year when the Italian artist Michelangelo"s (1475-1564, 意大利文艺复兴时期著名雕刻家、画家、
建筑师) birthday comes around, computer users all over the world are filled with fear (害怕) and use their
computers with care. Some may even choose not to turn on their computers on March 3. All this fear and care
are just because a deadly computer virus is ready to cause damages (破坏) on that day.
What"s a computer virus then? Why do people get so afraid of it?
A computer virus is, in fact, a little program that is put into other programs and that does something bad.
It is called a virus because, like any real-life viruses such as AIDs virus, it reproduces itself. And when these
programs are run, the virus is brought to life. It hides itself in your computer system waiting for the right
moment to make damages. And at the same time it keeps producing itself by copying itself onto other programs.
The Michelangelo virus waits until the artist"s birthday comes around, and then it will wake up to do very
bad things like destroying you files (毁坏文档). So next time when you turn on your computer, look out for
computer viruses!
Solar energy application
Batteries can power anything from small sensors to large systems. While scientists are finding ways to
make them smaller but even more powerful, problems can arise when these batteries are much larger and
heavier than the devices themselves. University of Missouri(MU) researchers are developing a nuclear energy
source that is smaller, lighter and more efficient.
"To provide enough power, we need certain methods with high energy density (密度)", said Jae Kwon,
assistant professor of electrical and computer engineering at MU. "The radioisotope (放射性同位素) battery
can provide power density that is much higher than chemical batteries."
Kwon and his research team have been working on building a small nuclear battery, presently the size and
thickness of a penny, intended to power various micro / nanoelectromechanreal systems (M/NEMS). Although
nuclear batteries can cause concerns, Kwon said they are safe.
"People hear the word "nuclear" and think of something very dangerous," he said, "However, nuclear power
sources have already been safely powering a variety of devices, such as pace-makers, space satellites and
underwater systems."
His new idea is not only in the battery"s size, but also in its semiconductor (半导体). Kwon"s battery uses
a liquid semiconductor rather than a solid semiconductor.
"The key part of using a radioactive battery is that when you harvest the energy, part of the radiation energy
can damage the lattice structure (晶体结构) of the solid semiconductor," Kwon said, "By using a liquid semicon
ductor, we believe we can minimize that problem."
Together with J. David Robertson, chemistry professor and associate director of the MU Research Reactor,
Kwon is working to build and test the battery. In the future, they hope to increase the battery"s power, shrink
its size and try with various other materials. Kwon said that battery could be thinner than the thickness of
human hair.
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