By installing personal terminals for Shiho Miyano and Akemi Miyano, Fang Zheng successfully made them believe his claims. Especially Shiho Miyano, although she wasn't from the electronic industry academic background, any cutting-edge technology research would require high precision tech. Therefore, after discovering that this tiny thing, about the size of a pinky nail, possessed computational power far beyond the most advanced supercomputers by thousands of times, Shiho Miyano had to accept Fang Zheng's claims.
After all, whether from craftsmanship or manufacturing technology, this thing absolutely doesn't resemble something current Earth technology could accomplish.
So either it popped out of a crack in a rock, or it was created by a higher civilization... the latter clearly makes more logical sense.
