| 摘要 |
Glass compn. without PbO and other easily deoxidizing metallic oxides, which is suitable for telescreen has the wt. compn. % based on oxides calcd. from batch: SiO2 43-45%, Al2O3 0-4%, ZnO 10-18%, CaO 0-5%, SrO 2-14%, BaO 10-20%, CaO + SrO+ BaO 16-35%, CeO2 0.3-1%, ZrO2 2-8%. This compn. gas the characteristics of: elec. resistance above 107-Cm; thermal expansion coeff. below 102 z 10-7/≦̸C, internal liquid below 900≦̸C; strain point below 500≦̸C; softening point below 690≦̸C; linear X-ray absorption coeff. of 0.6A≦̸; high endurability against discoloration owing to X-ray and elec. shock.
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