| 摘要 |
The invention concerns glasses that have a refractive index of more than 1.880, an Abbe number of more than or equal to 30.4, and a density of more than 4.1, and having the following chemical composition, expressed in wt.%, based on the oxides: SiO2: 6-9, B2O3: 15-19, with SiO2+B2O3<26, Nb2O5: 12 to<20.5, ZrO2: 8-10, TiO2: 7-11, La2O3: 23-32, with ZrO2+TiO2+La2O3: >/=44, CaO: 8 to<13, SrO: 0-2, BaO: 0-2, MgO: 0-2, ZnO: 0-5, with CaO+SrO+BaO+MgO+ZnO: >/=9, Y2O3: 0-5, WO3: 0-5, Li2O+Na2O+K2O: 0-2, others 0-1. |
