| Реферат: | eng: Data on the refractive index, density, and bulk modulus variations of Di64An36 glass, which is used as a model basalt melt, were obtained with a polarization interference microscope and a high-pressure diamond anvil cell at ambient temperature and pressure up to 5. 0 GPa. An anomalous decrease in the bulk modulus, Kt, was observed in the pressure range 0-1. 0 GPa. The values of the zero-pressure isothermal bulk modulus, Kt,0 = 22. 2, and variation of the bulk modulus with pressure, ΔKt/ΔP = 11. 35, were derived using a linear equation relating Kt and P over the pressure range with the normal behavior of the compressibility. A comparison of our results with previous data on other glasses and melts showed that the bulk moduli of silicate glasses are similar to those of corresponding melts. The values of the pressure coefficient of the bulk moduli, ΔKt/ΔP, for glasses derived from linear equations are 2. 5 times higher than the pressure derivative of the bulk modulus, K′T, derived using the Birch-Murnaghan equation for corresponding melts. The difference in ΔKt/ΔP and K′T has an effect on the compressibility of glasses and melts. The compressibility of glasses up to 5. 0 GPa calculated as (d - d0)/d is almost two times lower than that of corresponding melts. © 2012 Pleiades Publishing, Ltd.
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