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Submitted on: 13 May 2011.
Revised on: 15 July 2011.
Accepted on: 04 August 2011.
___________________DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS-SERIES B
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http://reply.papertrans.cn/1/76/7540/7540-34.png
Submitted on: 15 October 2009.
Revised on: 09 February 2010.
Accepted on: 26 February 2010.
___________________DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS-SERIES B
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