SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4197-4
Deep-blue organic light-emitting diodes (OLEDs) remain the most challenging primary-color emitters due to stringent exciton energy requirements. We strategically designed two innovative deep-blue emitters, SCZ-4AnCN and STPA-4AnCN, via systematic functionalization of an anthracene core with arylamino-decorated spirofluorene donors and cyano-substituted phenyl acceptors. Comprehensive theoretical and experimental analyses demonstrate that these spirofluorene-anthracene hybrids adopt precisely engineered distorted configurations, effectively suppressing detrimental intermolecular π–π stacking in condensed phases. The sp3-hybridized bridgehead carbons in spirofluorene units play a pivotal role by simultaneously restricting π-conjugation extension and fine-tuning donor–acceptor interactions, thereby stabilizing the lowest excited singlet (S1) state with dominant local excitation (LE) character. This molecular engineering yields exceptional deep-blue emission with remarkable efficiency. Notably, the materials exhibit unique high-lying reverse intersystem crossing (hRISC) behavior, enabling efficient triplet harvesting. Optimized doped devices incorporating SCZ-4AnCN achieve outstanding performance, including a maximum external quantum efficiency (EQE_max) exceeding 10% and CIE coordinates (0.154, 0.052) approaching the BT.2020 blue standard. Nondoped devices maintain impressive performance with an EQE_max of 7.51% and superior operational stability, demonstrating less than 10% efficiency roll-off at 1000 cd m−2. This work validates anthracene-based molecular architectures for deep-blue electroluminescence and establishes a transformative design paradigm for next-generation OLED emitters.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202604028
Accurate accounting of county-level carbon budgets and their spatio-temporal evolution is essential for formulating low-carbon development strategies tailored to each division and achieving carbon peak and neutrality goals. This study constructed a comprehensive, accurate, and unified model to measure terrestrial ecosystem carbon absorption, anthropogenic carbon emissions, and net carbon budget from 2010 to 2020 across the Xinjiang Production and Construction Corps and its divisions. Results indicate: (1) Terrestrial ecosystems consistently acted as net carbon sinks, but total carbon absorption declined slowly, with carbon sequestration capacity persistently decreasing. Cultivated land, the sole carbon source, expanded rapidly into forests and grasslands. Anthropogenic carbon emissions rose steadily, with growth rates sharply decelerating after 2015, exhibiting a spatial pattern of "high in the north and east, low in the south and west." (2) Total carbon emissions/absorptions increased rapidly from 2010 to 2015, then slowed from 2015 to 2020. Energy consumption dominated, contributing over 95% of emissions in each division and 99% regionally. High-emission zones expanded eastward from the 8th Division in the Junggar Basin; by 2020, the 8th, 13th, and 6th Divisions, occupying 26.52% of the land area, carried 78.16% of net carbon emissions, marking them as high-density emission zones. (3) Carbon balance zoning in 2020 identified one carbon sink functional zone, nine low-carbon maintenance zones, and three high-carbon optimization zones, the latter concentrated in a strip in the central-eastern region covering 26.52% of the area.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4082-6
High-performance nonvolatile memory devices are crucial for next-generation computing, yet achieving low-power, stable, and reproducible resistive switching remains challenging, primarily due to stochastic filament formation and limited precise control over the electronic properties of active materials. Herein, we employ a rational molecular engineering strategy to address these limitations by constructing a series of two-dimensional pyrene-based covalent organic frameworks (Py-COFs)—Py-H, Py-CH3, and Py-OH—via systematic substitution (–H, –CH3, and –OH) on the phenyl linkers to modulate backbone electronics. The electron-donating –CH3 and –OH motifs enrich the π-conjugated backbone with higher electron density, while the –OH moiety in Py-OH further engages in p-π conjugation with the benzene ring and forms intramolecular hydrogen bonds, thereby increasing framework rigidity, enhancing orbital overlap, and promoting charge delocalization. Enabled by these structural refinements, Py-OH-based devices exhibit markedly improved resistive switching behavior, characterized by a low operating voltage, an ON/OFF ratio of ~10^3.45, and excellent retention stability. Combined photophysical, electrochemical, and high-resolution TEM analyses corroborate that hydroxyl-driven p-π conjugation, hydrogen-bond reinforcement, and the emergent nanowire-like morphology synergistically suppress uncontrolled filament formation and promote efficient charge transport. These findings establish a clear structure-property correlation in functionalized Py-COFs and underscore their promise as tunable active layers for low-power, high-performance resistive memory and neuromorphic computing.