Science Bulletin最新文献

Narrowband multiple resonance (MR) emitters with circularly polarized luminescence (CPL) hold significant promise for three dimension organic light-emitting diode (3D-OLED) displays. In this work, we present a simple method for developing a new type of 9,9'-spirobifluorene-based CP-MR emitters by a recrystallization resolution technology and chlorine (Cl)-directed electrophilic borylation reaction, both of which significantly enhance the efficiency and scalability for mass production. This approach allows for integrating an asymmetric 9,9'-spirobifluorene core between two MR frameworks to achieve optically active CP-MR emitters. The highly rigid spirobifluorene framework minimizes structural relaxation, and meanwhile, the introduction of a cyano (CN) group enhances the MR emission characteristics, leading to an ultra-narrowband blue emission with full width at half maximum (FWHM) of 14 nm. As a result, these molecules facilitate the assembly of narrowband blue CPL-OLEDs with a maximum external quantum efficiency (EQE_max) of 30.7% and an impressive narrow FWHM of 16 nm, representing the first instance of an FWHM below 20 nm in CPL-OLEDs.

The core-mantle differentiation process plays a pivotal role in redistributing material on a massive scale, shaping the long-term evolution of rocky planets. Understanding this process is crucial for gaining insights into the accretion and evolution of planets like Mars. However, the details of Mars's core-mantle differentiation remain poorly understood due to limited compositional data for its core and mantle. In this study, we aim to constrain the Martian core-mantle differentiation by examining FeO partitioning between core and mantle materials, incorporating improved Martian compositional data from the InSight mission. Using ab initio thermodynamic techniques, we calculated the FeO partition coefficient between liquid iron and silicate melt. Our results align with previous studies while also clarifying the factors affecting partitioning behavior. Based on these findings and estimates of oxygen concentration in the core, we infer that Mars's core and mantle likely differentiated at temperatures above 2440 K and pressures ranging from 14 to 22 GPa. Although these estimates are higher than previously reported, they are consistent with observed abundances of moderately siderophile elements and Mars's accretion models.

The challenges posed by the non-conductive nature of iodine, coupled with the easy formation of soluble polyiodides in water, impede its integration with zinc for the development of advanced rechargeable batteries. Here we demonstrate the in-situ loading of molybdenum carbide nanoclusters (MoC) and zinc single atoms (Zn-SA) into porous carbon fibers to invoke electrocatalytic conversion of iodine at the interface. The electronic interactions between MoC and Zn-SA lead to an upshift in the d-band center of Mo relative to the Fermi level, thus promoting the interfacial interactions with iodine species to suppress shuttle effects. Notably, the optimal charge delocalization, induced by d-p orbital hybridization between molybdenum and iodine, also lowers the redox energy barrier to promote the interfacial conversion. With interfacial electrocatalysis minimizing polyiodide intermediates via a favorable redox conversion pathway, zinc-iodine batteries therefore demonstrate a large specific capacity of 230.6 mAh g^-1 and the good capacity retention for 20,000 cycles.