^pof;
Energy;
and;
Resources;
Engineering,;
College;
of;
Engineering,;
Peking;
University,;
Beijing;
100871,;
China;
^pConversion;
Research;
Center,;
Department;
of;
Mechanical;
Engineering,;
Doshisha;
University,;
Kyoto;
630-0321,;
Japan;