Department of Engineering Physics;
Tsinghua University;
Beijing 100084;
China;
Key Laboratory of Global Change and Marine-Atmospheric Chemistry;
State Oceanic Administration;
Xiamen 361005;
China;
Key Laboratory of Particle & Radiation Imaging (Tsinghua University);
Ministry of Education;
Beijing 100084;
China;
Key Laboratory of High Energy Radiation Imaging Fundamental Science for National Defense;
Beijing 100084;
China;