National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology;
Chinese Academy of Sciences;
Nanjing 210042;
China;
Key Laboratory of Astronomical Optics & Technology;
Nanjing Institute of Astronomical Optics & Technology;
Chinese Academy of Sciences;
Nanjing 210042;
China;
Physics and Astronomy Department;
California State University Northridge;
18111 Nordhoff Street;
Northridge;
California 91330-8268;
USA;
National Solar Observatory;
Boulder;
CO 80303;
USA;