Abstract:The investigation of dynamic behaviors in glassforming liquids is essential for comprehending glass formation, glass transition, and glass properties. In this work, the temperature dependence of equivalent viscosity in As2S3 glass across a broad range of deep undercooling temperatures was systematically investigated by integrating the distinct timescales and measurement advantages of conventional calorimetry and ultrafast calorimetry with temperature modulation techniques. The alignment between the equivalent viscositytemperature data and the actual viscositytemperature data was verified, and the relationships between viscosity or equivalent viscosity and temperature across the entire temperature range were accurately modeled using the MYEGA equation with consistent parameters. The liquid dynamic fragility of As2S3 glass was determined to be 39, slightly exceeding the fitted fragility value within the relatively narrow temperature band close to the glass transition temperature. This research not only illustrates the viability of using calorimetry to gauge equivalent viscosity in glassforming liquids but also presents a fresh approach and benchmark for evaluating the liquid dynamic behaviors of such liquids across wider and deeper supercooled zones, offering novel perspectives on exploring anomalous fragilitystrong transition phenomena.