Science Bulletin最新文献

Aqueous zinc-ion batteries (AZIBs) are promising for energy storage. However, Zn anode instability-caused by dendrite growth, hydrogen evolution reaction (HER), and by-product formation-limits their practical viability. HER, in particular, accelerates Zn consumption, disrupts electrode integrity, and induces local alkalization, exacerbating passivation. Conventional strategies emphasize electrolyte formulation and surface passivation, yet few address the underlying electronic origin of HER on Zn. Here we report a catalysis-inspired strategy that electronically modulates Zn reactivity via d-band center engineering to intrinsically suppress HER. By introducing oxalic acid (OA) as a molecular additive, we achieve a significant downward shift in the Zn d-band center (from -6.896 to -7.062 eV), weakening hydrogen adsorption and fundamentally reducing HER activity. In parallel, OA disrupts the Zn²⁺ solvation structure by displacing coordinated SO₄^2- anions, suppressing interfacial by-product formation. These dual effects yield unprecedented performance: Zn||Zn symmetric cells operate stably for over 3500 h; Zn||Cu cells exhibit 99.41% Coulombic efficiency over 1500 cycles; and Zn||I₂ cell retain 92.8% capacity after 10,000 cycles; the 1.3 Ah Zn||I₂ pouch cell presents good cyclability. This work pioneers a surface electronic tuning paradigm in battery design, extending catalytic d-band theory to electrochemical interfaces for HER suppression and interfacial stabilization in aqueous metal batteries.

The conserved histone variant H3.3 plays pivotal roles in heterochromatin formation and retrotransposon silencing. However, the molecular mechanism underlying H3.3-primed heterochromatin regulation remains elusive. Here, we demonstrate that H3.3-specific Ser31 phosphorylation and Lys27 trimethylation synergistically promote H3K9me3-heterochromatin formation. Mechanistically, polycomb protein chromobox homolog 7 (CBX7) preferentially binds Ser31-phosphorylated H3.3K27me3 nucleosomes and then recruits KRAB-associated protein 1 (KAP1), which may further engage the histone lysine 9 methyltransferase to establish H3K9me3-associated heterochromatin. Remarkably, H3K9me3 is significantly impaired when the H3.3-CBX7 interaction is disrupted, accompanied by the activation of retrotransposons. Moreover, during X-chromosome inactivation (XCI), H3K9me2/3 fails to accumulate at the inactive X (Xi) when blocking the H3.3-CBX7-KAP1 axis. Taken together, our results reveal a novel molecular mechanism by which H3.3 Ser31 phosphorylation (H3.3Ser31p) facilitates H3K9me3-heterochromatin formation during retrotransposon silencing and XCI via the H3.3K27me3-CBX7-KAP1 axis.

Understanding Precambrian seawater pH is critical for unraveling Earth's early marine environments and biospheric evolution. Yet, quantitative constraints remain elusive due to the lack of robust proxies. Here, we demonstrate that yttrium/holmium (Y/Ho) fractionation during adsorption onto marine sediments serves as a novel and reliable pH proxy. Experimental results reveal that Y/Ho fractionation in ferruginous sediments follows a pH-dependent power-law relationship, while in argillaceous sediments, it is jointly controlled by pH and salinity at low salinities (<29‰) but stabilizes (Kd_Y/Ho ≈ 0.4) at higher salinities (≥29‰). Temperature exerts a negligible influence, ensuring broad applicability across geological timescales. Leveraging these relationships, we develop a quantitative method to reconstruct paleo-seawater pH using Y/Ho ratios from coexisting ferruginous and argillaceous sediments. Validation against modern and Phanerozoic records confirms the proxy's accuracy (e.g., pH 8.21 ± 0.22 for modern Pacific sediments). Application to Neoproterozoic meta-pelites and iron formations reveals prolonged oceanic acidification (pH 5.9-6.4), deviating from previous model-based neutral-to-alkaline estimates. This acidic state, likely sustained by CO₂ outgassing from carbonatite-alkaline volcanism during Rodinia's breakup, challenges conventional views of Precambrian ocean chemistry. Our findings provide a transformative tool for probing early Earth's environmental dynamics and highlight the interplay between tectonics, magmatism, and marine pH evolution.