题干

(2009·江苏高考)在β衰变中常伴有一种称为“中微子”的粒子放出.中微子的性质十分特别,因此在实验中很难探测.1953年,莱克斯和柯文建造了一个由大水槽和探测器组成的实验系统,利用中微子与水中H的核反应,间接地证实了中微子的存在.
(1)中微子与水中的H发生核反应,产生中子(n)和正电子(e),即
中微子+H→n+e
可以判定,中微子的质量数和电荷数分别是________.(填写选项前的字母)

A:0和0

B:0和1

C:1和0

D:1和1

上一题 下一题 0.0难度 选择题 更新时间:2019-11-07 12:13:01

答案(点此获取答案解析)

A

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    A cat is recovering in California after surviving a 6,500-mile journey across the Pacific stowed inside a Chinese shipping container without food or water. Staff and volunteers have named it “Ni Hao”, which is Chinese for “hello”.

    It was discovered breathing shallowly after a two-week trip across the Pacific Ocean. The cat was seriously suffering from loss of water and starvation when the container was opened in California last week, but was said to be doing well after being sent to the Carson Animal Care Centre in Los Angeles. At first it was too weak to stand, but finally took its first steps. Then it ate a good meal and slept soundly. The cat woke up on Thursday morning, physically in a better condition than 24 hours ago.

     “Ni Hao greeted the medical team with its first meow this morning and is attempting to stand,” said Marcia Mayeda, head of the Los Angeles Department of Animal Care and Control. Aaron Reyes, director of the Department, added, “We finally got to hear its voice. It sounds like a single-engine plane.”

    Ni Hao is expected to be observed for 60 days but afterwards animal workers will look forward to providing it with a good shelter. “It's much better for it to recover in a home environment,” Mr. Reyes said. “It's just like a human being in a hospital so we're hoping to move it.” He added, “Little by little we're getting there. We're hoping that under the treatment and with rest, it'll be able to recover quickly.”

    It was not immediately clear how the cat got into the container.