Конспект лекций по термодинамике. Коренблит С.Э. - 58 стр.

                                                               |58|
                      @U !
 dU (T; M)  @T dT + @ M dM = CMdT + H T @T  @@U !
                                               H ! !
                                                    dM; (6.16)
                M          T                      M
  çâ® ¤«ï: H =) M
                                         0
                  ; ¤ ¥â: dS =) CM dT + T MdM;         (6.17)
                                T    T                                                      2
                                                                                              T
                                  @H !        @M !       @ M !
                                                               ¨«¨ T T )
                                                               ()           (0       2
                                                                                              ¨«¨ H
                                          T H L T @ H T ; (6.18)                             ()
                                                          2                                           2

  CH CM = T @ M                                                                           2


                       T @T H
¯à¨ M =L M(H=T ). „«ï ¤¨ ¬ £­¥â¨ª á (dT )0 = 0 ¨ ¨¤¥ «ì­®£® « ­¦¥-
¢¥­®¢áª®£® ¯ à ¬ £­¥â¨ª (6.14) ¯à¨ CM = const ¨¬¥¥¬ ᮮ⢥âá⢥­­®:
        S d S d = CMd ln T ; U  d   U  d = Cd T + M ;        (6.19)
                                                              ( )           ( )
                                                                                                      2


                      0
                         T                    M     2dT                0
                                              0



        S p S p =L) CMp ln T   M ; U  p U  p =) C p T;        2

                                                               (6.20)           ( )           ( )
                      0
                           T 2                   0
                                                   L M                                    0



        ¯à¨ç¥¬: CHd CM   d = 0; C p C p > 0 :                  (6.21)
                                   H      M

  1.1     Œ £­¨â­®¥ ®å« ¦¤¥­¨¥
    „«ï ¤®á⨦¥­¨ï ᢥàå­¨§ª¨å ⥬¯¥à âãà ¨á¯®«ì§ã¥âáï ¯à®æ¥áá ¤¨ -
¡ â¨ç¥áª®£® à §¬ £­¨ç¨¢ ­¨ï ¯ à ¬ £­¥â¨ª , ª®â®àë©, ¢ ᨫã (6.10), å -
à ªâ¥à¨§ã¥âáï ª®íää¨æ¨¥­â®¬ ®å« ¦¤¥­¨ï (â.ª. CHp  T , ¯à¨ T ! 0):                                        3




    @T ! = @ (H; T ) @ (M; H) = T @ M ! =) H @ M ! =) (6.22)
   @ H S @ (H; S ) @ (H; T )    CHp @T! H L CHp @ H T
  =:) Hp  T > 0; â.¥.: 
T = @T 
H < 0; ¯à¨: 
H < 0: (6.23)
                                    @H
                              4

 (6 14)C TH                                                                       S
 áᬮâਬ ¯®¤à®¡­¥¥ íâ®â ¯à®æ¥áá ®å« ¦¤¥­¨ï. C¯¥à¢ ¨§®â¥à¬¨ç¥áª¨,
¯à¨ ⥬¯¥à âãॠT , ­ ¬ £­¨â¨¢ ¯ à ¬ £­¥â¨ª ¤® ¢¥«¨ç¨­ë M ¯à¨ ­ -
¯à殮­­®á⨠¯®«ï H , à §¬ £­¨â¨¬ ¥£® § ⥬ ¢ ¤¨ ¡ â¥. „«ï ãà ¢­¥­¨©
                                  1                                                                                   1




íâ¨å ¯à®æ¥áᮢ ­ ¯«®áª®á⨠(M; H), ¯à¨ CM = const, ¨§ § ª®­ Šîà¨
                                      1




(6.14) ¨ ¨§ (6.20), ¨¬¥¥¬, ᮮ⢥âá⢥­­®:
 T  M  H (=  H ; â.¥.: 0  H  H ; ¯à¨: 0  M  M ; (6.24)
              1
  1
                    M                                                       1                                     1



                     p ln H M ; S p (M; H) S p (M ; H ) = (6.25)
              1



 S p (M; H) Se p = CM
                                                                2




                       ! MM 2M
                          0                                                                               1   1




 = CM p ln H     ln M            =) 0; â.¥.: H>(M) = T M; (6.26)
                                                      2             2
                                                                                                                  1


           H        M
                                                                    1


                  1         2            1