. , . , .
. 4.6. 1, 2, , 3, 4. 2. . 5.
, , , . - .
10-3 10-4 . . , "", , . , . , , .
, . R = f(x) (. 4.7, a) (. 4.7, ). D = l
(4.51)
dR/d R = f(x) .
(4.52)
r 1 ; l ; h ; b . (4.51) (4.52) h
(4.53)
, dR/dx = const .
, . - (. 4.8, ), , , . , . 4.8, - .
. (. 4.9, ). R . R . R (R > > R p), R ,
|
|
(4.54)
R.
R = (Rp/l)x, U
(4.55)
, R Rp, . R , Ri Ux (. 4.9, ). R .
(4.56)
Ux (4.54),
(4.57)
. 4.9, a
(4.58)
(4.58) (4.57),
(4.59)
b = R/Rp ; a = Rp/R .
U b a . 4.10. a , a b <<1 ( ), U b. a , a. (4.54), 1 . 4.11, ,
(4.60)
Ux = b U U,
(4.61)
a < 0,1 b = 2/3.
(4.62)
a, .. R . . . 2. 3. , , 0 , b, b . d, . , R? , R = R R? (. 4.11, ).
. . .
(4.63)
( ) , , . .
|
|
. D R . , "", ,
(4.64)
Rp .
, "" . Rp = nD R
(4.65)
n .
, . , .
, , .