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原子核衰变规律有两个表达式N=N_0(1/2)~(t/T)和N=N_(0e)~(t/τ)=N_0(1/e)~(t/τ),这是为什么呢?对于该问题的解答需从瞬态过程及其时间常数谈起.时间常数是用来表示瞬态过程变化快慢的物理量,其符号是τ,国际单位是s(秒).各种形式的瞬态过程具有不同形式的时间常数公式.当原子核数目足够大时,如果在很短的时间dt内,有dN个核发生衰变,则由统计规律可知,改变率(dN)/(dt)必与当时存在的总原子核数目成正比,即-(dN)/(dt)=λN.式中λ为比
There are two expressions for the decay of nuclei: N = N_0 (1/2) ~ (t / T) and N = N_ (0e) ~ (t / τ) = N_0 (1 / e) Why? The answer to this question is to start with the transient process and its time constant, which is a physical quantity used to express the speed of the transient process, with the sign τ and the international unit s (seconds) When the number of nuclei is large enough, if there are dN nuclei decaying within a short time dt, then the statistical rule shows that the rate of change (dN) / (dt) ) Must be proportional to the total number of nuclei present at that time, ie - (dN) / (dt) = λN where λ is the ratio