Submitted on: 15 October 2013.
Revised on: 21 January 2014.
Accepted on: 11 March 2014.
___________________Journal of Astronomy and Space Sciences
Submitted on: 26 March 2017.
Revised on: 19 May 2017.
Accepted on: 11 June 2017.
___________________Journal of Astronomy and Space Sciences
Submitted on: 03 March 2010.
Revised on: 13 April 2010.
Accepted on: 27 May 2010.
___________________Journal of Astronomy and Space Sciences
Submitted on: 17 January 2016.
Revised on: 17 February 2016.
Accepted on: 29 February 2016.
___________________Journal of Astronomy and Space Sciences
http://reply.papertrans.cn/2/155/15454/15454-25.png
http://reply.papertrans.cn/2/155/15454/15454-26.png
http://reply.papertrans.cn/2/155/15454/15454-27.png
Submitted on: 17 July 2019.
Revised on: 14 September 2019.
Accepted on: 02 October 2019.
___________________Journal of Astronomy and Space Sciences
http://reply.papertrans.cn/2/155/15454/15454-29.png
Submitted on: 15 April 2007.
Revised on: 17 May 2007.
Accepted on: 07 July 2007.
___________________Journal of Astronomy and Space Sciences