1. Biophysics Section, Department of Physics, Faculty of Science Division II, Tokyo University of Science, 1-3 Kagurazaka,
Shinjuku, Tokyo 162-8601, Japan
2. VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi 10000, Vietnam
3. National Center for Technological Progress, 25 Le Thanh Tong, Hoan Kiem, Hanoi 100000, Vietnam
4. VNU University of Engineering and Technology, 144 Xuan Thuy, Cau Giay, Hanoi G2-206, Vietnam
5. Tokyo Diatomology Lab, 2−3-2 Nukuikitamachi, Koganei, Tokyo 184-0015, Japan