= Const = Const
- δA′, :
TdS ≥ dU + PdV + δA′ (2.62)
δA′≤ TdS dU PdV (2.63)
1 2 :
A′ ≤ T(S2 S1) (U2 U1) P(V2 - V1) (2.64)
A′ ≤ (U1 + PV1 - TS1) - (U2 + PV2 TS2) (2.65)
G:
U + PV TS = H TS = G (2.66)
, . , G . (2.66) :
A′≤ G1- G2 = - ΔG (2.67)
(2.67) , , (A = - ΔG). (, ) (A′< - ΔG).
, P = Const T = Const.
(2.66):
dG = dU + PdV + VdP TdS - SdT (2.68)
:
dS ≥ dU + PdV (2.69)
(2.68) (2.69), :
dG ≤ dU + PdV + VdP dU PdV SdT (2.70)
dG ≤ VdP - SdT (2.71)
(2.71) . = Const T = Const (2.71) :
dG ≤ 0 (2.72)
(2.72) : , P = Const
= nst, (, ) (dG <0). (dG = 0) . P = Const
T = Const 2.3
G
AB , ;
, ;
2.3 -
V = Const T = Const.
, G . G G = (P,T), :
dF = (2.73)
, :
|
|
dG = VdP SdT (2.74)
(2.73) (2.74) :
(2.75)
, V S. (2.75) , - , = Const. - , .
3
3.1 .
. () ():
;
() ():
;
( ) ():
;
:
( 1) ( 2)
. .
1 2.
1 :
dG1 = V1dP S1dT (3.1)
2 :
dG2 = V2dP S2dT (3.2)
:
dG = dG2 dG1 (3.3)
Ec , dG = 0 dG1 = dG2. :
V2dP S2dT = V1dP S1dT (3.4)
(3.5)
,
S2 S1 = ΔS = (3.6)
(3.6) (3.5) :
, (3.7)
Δ , /;
V2 2;
V1 1.
(3.7) . . .