Sparks created in a lab give off X-rays, scientists announced Monday.
X-rays are a byproduct (副产物) of high-energy electron discharges in the Sun, in exploding stars, and even in lightning. Many scientists did not expect sparks alone to do the trick.
Researchers at Florida Institute of Technology brought their equipment, which had detected X-rays in lightning, into the lab. Half the team expected to see X-rays and the other half did not.
In sparks of 1.5 million to 2 million volts, the researchers indeed recorded X-rays that were remarkably similar to those produced by lightning.
"This amazed us, It opens the door to answering really big questions about lightning by generating it in the lab," said team member Hamid Rassoul. "It also tells us that we have a lot’ to learn about how even small sparks work."
X-rays are a form of electromagnetic radiation, on a spectrum (频谱) that runs from radio waves on the low
A. It means "creating".
B. It means "producing".
C. It means "inventing".
D. It means "doing".
Aside from. perpetuating itself, the sole purpose of the American Academy and Institute of Arts and Letters is to "foster, assist and sustain an interest" in literature, music, and art. This it does by enthusiastically handing out money. Annual cash awards axe given to deserving artists in various categories of creativity: architecture, musical composition, theater, novels, serious poetry, light verse, painting, and sculpture. One award subsidizes a promising American writer’s visit to Rome. There is even an award for a very good work of fiction that failed commercially—once won by kite young John.
Updike for The Poorhouse Fair and, more recently, by Alice Walker for In Love and Trouble The awards and prizes total about ＄750,000 a year, but most of them range in size from ＄5,000 to＄12,500, a welcome sum to many young practitioners whose work may not bring in that much money in a year. One of the advantages of the awards is that many go to the struggl
A. Harold Strauss and his wife both earns a good living.
B. Raymond Carver earns his living by writing short stories.
C. The money devoted by Harold Strauss and his wife would quickly drain out.
D. Diane Johnson and Robert Stone are not professional editors like Harold Strauss.
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