3. . .
,
, :
=Q/ΔT (3.5)
, (), , . , /(), /().
, Δ→0:
C = lim (Q/ΔT) = δQ/dT (3.6)
ΔT→0
δQ/dT , δQ , . :
δQ= dT (3.7)
:
T2
Q = ∫CdT (3.8)
T1
(3.8) (3.5) , :
T2
C = (1/ΔT) ∫CdT (3.9)
T1
, Q. . , , :
v = p =
v :
dH = dU + p dV = dU + p R/p *dT = dU + RdT
(V = RT/p dV = R/p dT)
= + R Þ Cp = C V + R ( 3.10 )
R , 1 1
, , , .
, , . , . . , .
. , . . , , . - , . , , , ( 5). , ( ) .
|
|
, .. . , . , kT, k
k = R/N = 1,38*10-23/. ( 3.11 )
, , , ,
Dev>> kT > Der ( 4.4 )
.
(He, Ar)
. . e = 1/2kT, 1- = 1/2RT. C, 3
U = 3/2 RT. ( 4.5 )
v = = 3/2 R ~ 3 /*K = 12,5 /,
Cp = C V + R = 5 /
.
3N , N . 6, 3 , 2 1 . 2, , . 5
U = 5/2 RT.
v = = 5/2 R ~ 5 /K = 20,8 /,
Cp = C V + R = 7 /,
, v → 6 /( ).
.
3N, 3 , 3 ( 2 ) 3N - 6 (5) . : () , , , , . , , , . : , . , .
, :
- -: , , 3R.
- - ( ): .
|
|
- - () , .
,
= + b + 2 + dT3; ( 4.9)
= + b + ' -2. ( 4.10)
298 . :
= Drp.
Drp. = D + DbT + DcT2 + Dd T3 + Dc'T-2.
1. Dr = 0 DrT1= DrT2. .
2. D >0, T Dr Dr2 > Dr1.
½Dr2½ <½Dr1½.
3. D < 0, T Dr ¯ Dr2 < Dr1.
½Dr2½ >½Dr1½.