Submitted on: 21 August 2004.
Revised on: 04 September 2004.
Accepted on: 10 September 2004.
RSC Advances
Submitted on: 22 March 1998.
Revised on: 20 April 1998.
Accepted on: 06 May 1998.
RSC Advances---ROYAL SOC CHEMISTRY
http://reply.papertrans.cn/3/274/27343/27343-33.png
http://reply.papertrans.cn/3/274/27343/27343-34.png
Submitted on: 17 March 1998.
Revised on: 02 April 1998.
Accepted on: 15 April 1998.
RSC Advances---ROYAL SOC CHEMISTRY
http://reply.papertrans.cn/3/274/27343/27343-36.png