1.5.1. :
- a -, , a- ( 4 ... z = 2), , ;
- b-, , ; : , - ; - b-;
- g- - , , -;
- - , ; , .
1.5.2. :
( , ) .
, (1.5.1)
N(t), -3 - t;
dN/dt, -3-1 - , 1 3 1 ( );
l, c-1 - , .
(1.5.1) .
(1.5.1) (t = 0 N = No), :
N(t) = No exp(-lt), (1.5.2)
:
, - .
(1.5.2) .
1.5.3. l,
T = 1/l, (1.5.3)
( , ).
- , = 2.7182818... .
, N(T)/No = exp(-T/T) = e-1 = 1/e.
, (1/2), , 2 .
|
|
, 1/2 - . , t = T1/2 N(T1/2) / No = 1/2, exp(- T1/2/T) = 1/2,
1/2/T = ln2 0.693, ,
1/2 0.693 , 1.44 1/2 (1.5.4)
1.5.4. :
:
(1.5.5)
1.5.5. , , , ( t). , , , .
, 1% , , (.1.3), 6-7 4-5 .
N(t)/No
1.0 T 2T 3T 4T 5T t
0.5
1/e
0.25
1/e2
0.125
0.0625 1/e3
0.03125 1/e4 1/e5
0.0156 t
0.0078 0 1/2 2T1/2 3T1/2 4T1/2 5T1/2 6T1/2 7T1/2
.1.3. .
: , .