Cheebtsam ntawm lub koob yees duab Lub koob yees duab yog tsim los ntawm ib tug optical iav lens.Cov iav kho qhov muag yog ua los ntawm high-purity silicon, boron, sodium, potassium, zinc, lead, magnesium, calcium, barium thiab lwm yam oxides tov raws li ib qho kev qhia tshwj xeeb, yaj hauv platinum crucible ntawm qhov kub thiab txias, ...
Nyeem ntxiv