试题与答案

核聚变能以氘、氚等为燃料,具有安全、洁净、储量丰富三大优点,是最终解决人类能源危

题型:问答题

题目:

核聚变能以氘、氚等为燃料,具有安全、洁净、储量丰富三大优点,是最终解决人类能源危机的最有效手段.

(1)两个氘核

 21
H结合成一个氦核
 32
He
时,要放出某种粒子,同时释放出能量,写出核反应的方程.若氘核的质量为m1,氦核的质量为m2,所放出粒子的质量为m3,求这个核反应中释放出的能量为多少?

(2)要使两个氘核能够发生聚变反应,必须使它们以巨大的速度冲破库仑斥力而碰到一起,已知当两个氘核恰好能够彼此接触发生聚变时,它们的电势能为

e2
ε0(2R)
(其中e为氘核的电量,R为氘核半径,ε0为介电常数,均为已知),则两个相距较远(可认为电势能为零)的等速氘核,至少具有多大的速度才能在相向运动后碰在一起而发生聚变?

(3)当将氘核加热成几百万度的等离子状态时就可以使其获得所需速度.有一种用磁场来“约束”高温等离子体的装置叫做“托卡马克”,如图所示为其“约束”原理图:两个同心圆的半径分别为r1和r2,等离子体只在半径为r1的圆形区域内反应,两圆之间的环形区内存在着垂直于截面的匀强磁场.为保证速率为v的氘核从反应区进入磁场后不能从磁场区域的外边界射出,所加磁场磁感应强度的最小值为多少?(不考虑速度大小对氘核质量的影响)

答案:

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1.婉约 2.D 3.柳词借“晓风残月”抒发的是相恋之人的离别之苦;本词借“晓风残月”表达了因国破家亡而生的故国之思。(意对即可)

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