Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.mce.biophys.msu.ru/archive/doc15789/doc.pdf Дата изменения: Mon Oct 29 13:16:58 2007 Дата индексирования: Mon Oct 1 20:42:40 2012 Кодировка:

.., .., .. () - . , , . , -, -. . COMPUTER MODEL OF DIFFUSION IN IRRADATED POLYMERS Murashev V., Tarasevich K., Grachev E. (Moscow) Molecular distribution dependence of radiation dose is researched in this article. The system of differential equations describing this process and its solution was obtained. Computer model of polymer chain on basis of Rouse model with volume interaction describing by Lennard-Jones potential is represented. Also diffusion process of polymer chains in dissolvent was simulated by MonteCarlo method. The results of computer simulation allow determining diffusion coefficient dependence of molecules length. (, ). 289


3. (II)

, . . . [1], 10 ­ 40 , . [2], 300 ­ 350 :
Kn Pn Pr + Pn -r

K n = K (n - 1) ,

(1)

K ­ , , . , , :
d Pn = -(n - 1) KPn + 2 K dE
i = n +1





Pi ,

n = 1,

(2)

Pn - , n . 1 dL( E ) - . L(E) ­ K= L( E ) dE , , . * - , , . c p0 [2] ( ) :
E* = M0 , p0 N A

(3)

M0 ­ , NA ­ 290


.. . -- -10, 2002, .289-291

. dL( E ) E 1 (4) L( E ) = L0 - * , =- *, dE E E L0 ­ . :
K= 1 E* 1 , = L0 - E E * E0 - E

(5)

E0 = L0 E * ­ , . (5) (2), :
d 1 Pn = - (n - 1) Pn + 2 dE E0 - E i
=n





Pi , +1

n = 1,

(6)

{P0n }n

=1, , :
E Pn = Cn 1 - E 0
n -1

- 2C
n

n +1

E +C 1 - E0

n

n+2

E 1 - E 0

n +1

,

(7)

C Cn = P0 n + 2 Cn +1 - Cn + 2
Cn =
i=n

:





P0i ( i - n + 1 ) .

. , C1 A =



i =1



P0i i

-

, , C2 =
i=2



P0i ( i - 1 ) = L0 -

.
291


3. (II)

, (6) , :
E E Cn 1- - 2Cn+11- + Cn+ E E 0 0 n=1 n=1 E E = A - L01- = A - L0 + * E E 0

Pn =







n-1

n

2

E 1- E 0

n+1

E = C1 - C21- = E0

,

n =1





Pn = A - L0 +

E , .. E*

. . ­ : < n > = A
n =1





Pn .

: 1 1 E , = + < n > < n0 > AE *

(8)

< n0 > - . (3) E*, (8) : 1 1 = + p0 r , < n > < n0 > r ­ ( ). , [2], , (6). ­ , , , , . [3] ", " c , 292


.. . -- -10, 2002, .289-293

- . , , :
U W = min 1, exp - kT .

(9)

(link-cell method), . ( rmax = 4 3 ). , , , , . - « » , , , , . - , . . - , , 293


3. (II)

. ( ). :
cn 2 cn = Dn t x 2

(10)

cn - , n. «» , -, . (10) Dn , , Dn . , D ( N ) . «» , [0,1] . , , «» , 0 . [12] = A( D)c0 + . (25) A(D) ­ ,
294


.. . -- -10, 2002, .289-295

D , , (10) .

. 1. N.

D ­ (. [4]), . .1 Dn n, . , Dn = D0 N , [5]. . 1. .. . // , «», , 1979 2. . // , . 295


3. (II)

, , 1962 3. M., C. // , «», , 1998 4. .. , .. , .. // : , , , .6, 11, 1994 5. . //, 2- , «», , 1990 6. .. //-, - , « », , 1982 7. . // - , «», , 1982 8. . , . // , «», , 1995 9. K. Binder //Monte-Carlo and Molecular dynamics simulation in polymer science, Oxford University Press, 1995 10. .. , .. // , «», , 1989 11. .. , .. // , «», , 2000

296