ONE of China's six biggest, the new Yunnan Observatory in southwestern China has a main lens of 1,016 mm with a prime focal ratio of F/4, which allows very precise measurements of the spectrums and...
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ONE of China's six biggest, the new Yunnan Observatory in southwestern China has a main lens of 1,016 mm with a prime focal ratio of F/4, which allows very precise measurements of the spectrums and...