The 'excess oxygen' stored in deep Earth magma may help explain how Earth’s atmosphere became oxygen-rich
Peer-Reviewed Publication
Updates every hour. Last Updated: 21-Oct-2026 19:17 ET (21-Oct-2026 23:17 GMT/UTC)
A recent study published in National Science Review has revealed silicate magma can store far more oxygen than its chemically allows. In high-pressure experiments, silicate melt can store up to about 5 wt.% excess oxygen, which is released as the magma rising. The findings suggest that oxygen-rich magmas could carry oxidizing power from Earth’s interior toward the surface, and may explain links between large-scale magmatism episodes and atmospheric oxidation in Earth’s history.
This study proposes a novel transmission framework that integrates a nonlinear companding-based PAPR reduction method with the Digital Post-Distortion (DPoD) technique to balance power efficiency and Bit Error Rate (BER) performance. To recover the transmitted signals, a Successive Decision Feedback Nonlinearity Equalizer (SDFNE) is developed at the receiver side. The SDFNE employs a time-domain least squares equalizer with closed-loop iterative feedback to jointly mitigate companding distortion and PA nonlinearity. The proposed framework balances transmitter-side PAPR suppression and receiver-side nonlinear equalization. This enables the PA to operate closer to its saturation point while achieving excellent BER performance. Meanwhile, compliance with spectral emission mask requirements is maintained. Numerical results on diverse PA models demonstrate that the proposed transmission framework with the SDFNE method significantly outperforms conventional nonlinear signal processing methods, including nonlinear companding, digital predistortion, and DPoD. Superior BER performance is achieved in a power-efficient manner, making the proposed framework particularly suitable for resource-constrained communication systems.
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