dq, , du dw, . , , , ( ).
:
1. (υ = const) ;
2. (ρ = const) ;
3. (t = const) ;
4. (dq = const) ;
5. ,
ρυn = const
n (), , - .
. ρυ 1-2, . 1-2 (. 1), υ = const
. 1.
ρυ = RT υ = const: υdρ = RdT, , dT >0, d >0. dT <0, dρ <0, .. .
p1/p2 = T1/T2 (1)
, ρdυ= 0, , . ρυ-. , , , = 0.
:
∆uυ = qυ = cυm (t2 t1) (2)
, .
G V 3
Qυ = G cυm (t2 t1) = Vc´υm (t2 t1) (3)
. υ 1-2, . 1-2 (. 2), = const
. 2.
υ = RT = const: dυ = RdT, , dυ >0 dT >0. dυ <0, dT <0, .. , . q w , ∆u, .
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υ1/υ2 = T1/T2 (4)
1 2 (.2) (- 19 3) = const,
υ2
l = ∫ dυ = (υ2- υ1) (5)
υ1
ρυ-. 1 2 , (υ2- υ1) ρ, .. w = ρ (υ2- υ1). . dυ = RdT dw dw = RdT,
T2
l = ∫ RdT = R (T2 - T1) (6)
T1
G
L = GR (t2 - t1) (7)
G
L = Gρ (υ2- υ1) = ρ (V2-V1) (7)
G V 3
Qυ = G c ρm (t2 t1) = Vc´ρm (t2 t1) (8)
. , , . , , υ (.3). υ: υ = const
t = const. ρdυ = - υdρ. , dυ>0 d< 0 , .. , .
. 3.
, t= const cυdt = 0,
dqt = Apdυ (9)
1. dυ>0, dqt>0,.. , .
: dυ<0, dqt <0, .. , .
2. : dut = cυdt = 0, .. ut = const.
υ1 υ2
υ2
l = ∫ ρdυ
υ1
:
p1/ p2 = υ2/ υ1 (10)
p1/ p2 = V2/ V1 (11)
l = RT ln υ2/ υ1 (12)
l = RT ln p1/ p2 (13)
l = p1 υ1 ln υ2/ υ1 (14)
l = p1 υ1 ln p1/ p2 (15)
, - (12)-(15) , (14)-(15) υ V,
l = p1 V1 ln υ2/ υ1 (16)
l = p1 V1 ln p1/ p2 (17)
∆u = cυm (t2 t1) = 0 (18)
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,
qt = l (19)
. , , . , , , ..
dq =0 (20)
. , .
υ (. 4) : ρυk = const
k = ρ/ υ .
. 4
:
ρ υ p2/ p1 = (υ1/ υ2) k (21)
υ 2/ 1 = (υ1/ υ2) k-1 (22)
2/ 1 = (2/ 1) (k-1) / k (23)
1- -
0 = du + dl
dl = - du (24)
, dl>0, du <0, dl<0, du >0. (24)
D l = u1 u2 (25)
- : . .
∆u = cυm (t2- t1)