基金supported by the Doctoral Fund of Ludong University(LY2013001,LY201222)Science and Technology Development Projects of Shandong Province(2012YD01056)+2 种基金Shangdong Province Young and Middle-Aged Scientists Research Awards Fund(BS2013SF029)National Natural Science Foundation of China-Tianyuan Fund for Mathematics(11426126)Natural Science Foundation of Shandong Province(ZR2014AP007)