Submitted on: 16 July 2000.
Revised on: 07 October 2000.
Accepted on: 18 October 2000.
___________________Bulletin of the University of Karaganda-Physics
http://reply.papertrans.cn/1/44/4395/4395-32.png
Submitted on: 13 April 2016.
Revised on: 26 May 2016.
Accepted on: 13 July 2016.
___________________Bulletin of the University of Karaganda-Physics
Submitted on: 12 October 2023.
Revised on: 17 January 2024.
Accepted on: 02 February 2024.
___________________Bulletin of the University of Karaganda-Physics
Submitted on: 01 April 2014.
Revised on: 18 June 2014.
Accepted on: 11 August 2014.
___________________Bulletin of the University of Karaganda-Physics
Submitted on: 28 April 2001.
Revised on: 04 July 2001.
Accepted on: 04 August 2001.
___________________Bulletin of the University of Karaganda-Physics