The National Natural Science Foundation of China(Nos.61071117,61171158,61275077);the Natural Science Foundation Project of CQ CSTC(Nos.cstc2013jcyjA40052,cstc2012jjA40060);the Projects of the Education Council of Chongqing(No.KJ130515)
supported by the National Natural Science Foundation of China(Nos.61071117,61171158,61275077);the Natural Science Foundation Project of CQ CSTC(Nos.cstc2013jcyjA40052,cstc2012jjA40060);the Projects of the Education Council of Chongqing(No.KJ130515)