Submitted on: 05 June 2010.
Revised on: 14 July 2010.
Accepted on: 24 July 2010.
NULL
Submitted on: 13 May 2014.
Revised on: 30 May 2014.
Accepted on: 21 June 2014.
NULL
http://reply.papertrans.cn/3/262/26116/26116-23.png
Submitted on: 17 December 2005.
Revised on: 26 January 2006.
Accepted on: 15 February 2006.
NULL
http://reply.papertrans.cn/3/262/26116/26116-25.png
http://reply.papertrans.cn/3/262/26116/26116-26.png
Submitted on: 08 November 2003.
Revised on: 07 December 2003.
Accepted on: 15 December 2003.
NULL
http://reply.papertrans.cn/3/262/26116/26116-28.png
http://reply.papertrans.cn/3/262/26116/26116-29.png
Submitted on: 25 May 1999.
Revised on: 11 June 1999.
Accepted on: 02 July 1999.
NULL