Chalcopyrite (CuFeS 2 ) is the primary copper mineral worldwide, yet its hydrometallurgical extraction remains severely hindered by slow leaching kinetics, commonly attributed to surface passivation. Understanding the atomistic events governing the early stages of chalcopyrite surface oxidation is essential for developing more efficient and sustainable copper extraction technologies. In this work, a four-step oxidative mechanism on the CuFeS 2 ( 001 ) -S surface was investigated and characterized electronically. O 2 co-adsorption with H 2 O on Fe sites triggers charge transfer into antibonding π ∗ orbitals, activating O 2 into a superoxide-like intermediate. Subsequent proton transfer yields Fe-OOH and Fe-OH species, followed by the dissociative adsorption of a second H 2 O molecule onto the S-S dimer, forming S 2 OH intermediates accompanied by S-Cu bond elongation from 2.35 to 3.62  Å. In the final step, H 2 O adsorption on copper drives significant interfacial charge redistribution, with electronic states near the Fermi level progressively localized on oxygenated intermediates. Overall, iron, copper, and sulfur play distinct but electronically coupled roles in the progressive oxidative transformation of the chalcopyrite surface, providing atomistic insight into the early stages of passivation under hydrometallurgical conditions.

Antiferromagnetism and superconductivity are often viewed as competing orders in correlated electron systems. Here, we demonstrate that kinetic frustration in hole motion facilitates their coexistence within the square-lattice repulsive Hubbard model. Combining exact analytical solutions on tailored geometries with large-scale numerical simulations, we reveal a robust pairing mechanism: Holes on opposite sublattices behave as if they carry opposite effective charges due to spin singlet formation from kinetic frustration. This emergent property suppresses phase separation and fosters a coherent [Formula: see text]-wave superconducting channel embedded within a long-range antiferromagnetic background. Our findings establish a minimal yet broadly applicable framework for stabilizing strong-coupling superconductivity in doped Mott insulators.

Atmospheric new particle formation (NPF) has been observed across virtually all tropospheric environments, yet the meteorological conditions that favor or suppress it have resisted clear theoretical resolution. Here we show that, for neutral chemistries in which a strongly bound molecular pair constitutes the critical cluster, the thermodynamic precondition for NPF is set by a single quantity: the effective binding free energy of that pair, [Formula: see text], which captures the competing influences of temperature and relative humidity in a closed-form analytical framework. Applied to the sulfuric acid-dimethylamine system in the boundary layer, the theory reproduces observed clustering across laboratory experiments and field campaigns spanning a polluted megacity, a remote high-altitude site, and an ultra-pristine boreal peatland, all without kinetic fitting parameters; precursor concentrations and the condensation sink enter as separable factors that govern the subsequent production rate. The framework reveals an optimal [Formula: see text] that maximizes cluster production, providing a thermodynamic basis for why NPF peaks at midday, favors spring over other seasons, occurs under heat wave conditions despite temperatures approaching [Formula: see text]40 °C, and can even arise on rare evenings in near-pristine conditions. More broadly, the theory exposes the inherent relationship between atmospheric conditions and the earliest steps of particle formation, offering a general interpretive tool that complements and extends what observations and simulations alone cannot provide.

Simulations of the ocean wave climate are critical for assessment of coastal processes and hazards in observation sparse regions such as the Arctic. While the multidecade wind and ice datasets necessary for driving long-term wave simulations have proven reliable for such efforts, the presence of landfast ice along shorelines at scales not represented by these data has been a persistent uncertainty impeding accurate analysis of impacts to Arctic coasts. Here, we explore this uncertainty by producing a historical high-resolution wave simulation and combining simulation outputs with landfast ice data for the Alaskan Arctic. The resulting dataset yields an improved assessment of coastal waves and identifies stark contrasts in the seasonal wave exposure of the Chukchi and Beaufort regions. Notably, analysis shows that absent supplemented landfast ice, coastal ice cover is broadly underestimated by 10 to 25 d, resulting in wave energy being overestimated by 5 to 10% in shallow depths nearshore. Notably, these figures can reach up to 70 d of underestimation for ice cover and 48% overestimation of wave energy in certain locations. The persistent overestimation and potential for extreme positive biases in coastal wave assessment highlight the need for representation of landfast ice in Arctic coastal analysis efforts and our analysis reveals the spatial and temporal biases for related research.

The theory of fracture normally describes cracks as propagating discontinuities in a continuous medium where stresses vanish on free crack faces. We describe cracks instead at the particle level and obtain more general analytical results than were available previously. Using dynamical crack solutions for widely varying dissipation and general isotropic elastic moduli, we construct a catalog of 100,000 crack solutions and from it a general picture of when cracks are stable. For our exactly solvable model of dynamic fracture, the surface wave speed sometimes sets an upper limit on crack velocity, as expected. However tensile cracks traveling faster than the shear wave speed are possible and their stability is enhanced when they travel along weak interfaces, when dissipation increases, and when system sizes are small. Our results reinforce a standard view that supersonic cracks require supersonic energy transport near the tip, but we show it can come from dissipation as well as hyperelasticity.