Submitted on: 01 October 2004.
Revised on: 27 October 2004.
Accepted on: 19 November 2004.
Physica Status Solidi-Rapid Research Letters
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http://reply.papertrans.cn/3/246/24591/24591-33.png
Submitted on: 09 April 2002.
Revised on: 19 May 2002.
Accepted on: 03 June 2002.
Physica Status Solidi-Rapid Research Letters
http://reply.papertrans.cn/3/246/24591/24591-35.png
Submitted on: 10 June 2004.
Revised on: 02 July 2004.
Accepted on: 20 July 2004.
Physica Status Solidi-Rapid Research Letters