Submitted on: 07 August 2008.
Revised on: 10 September 2008.
Accepted on: 24 September 2008.
___________________Journal of Contemporary Physics-Armenian Academy of Sciences
Submitted on: 15 October 2020.
Revised on: 01 January 2021.
Accepted on: 07 February 2021.
___________________Journal of Contemporary Physics-Armenian Academy of Sciences
Submitted on: 07 October 2002.
Revised on: 25 January 2003.
Accepted on: 03 March 2003.
___________________Journal of Contemporary Physics-Armenian Academy of Sciences
Submitted on: 27 December 2002.
Revised on: 01 March 2003.
Accepted on: 13 March 2003.
___________________Journal of Contemporary Physics-Armenian Academy of Sciences
Submitted on: 16 August 2009.
Revised on: 11 December 2009.
Accepted on: 29 December 2009.
___________________Journal of Contemporary Physics-Armenian Academy of Sciences
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http://reply.papertrans.cn/2/162/16165/16165-27.png
Submitted on: 17 April 2011.
Revised on: 28 June 2011.
Accepted on: 13 August 2011.
___________________Journal of Contemporary Physics-Armenian Academy of Sciences
Submitted on: 29 January 2002.
Revised on: 17 May 2002.
Accepted on: 17 June 2002.
___________________Journal of Contemporary Physics-Armenian Academy of Sciences
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