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 Fuel Chemistry and Technology•2026•DOI: 10.3724/2097-213X.2025.JFCT.0031
The high-temperature behavior of biomass ash critically influences gasifier operational efficiency. This study investigates the differential high-temperature behaviors of corn straw ash (CSA) and wheat straw ash (WSA) using an intelligent ash fusion analyzer, high-temperature rotating viscometer, X-ray diffraction (XRD), SEM-EDS, and FactSage thermodynamic simulations. Both ashes contain high K2O (>30%) and exhibit flow temperatures below 1300 °C. Despite higher K2O and lower SiO2, CSA exhibits a higher flow temperature (1241 °C) than WSA, attributed to elevated CaO (10.39%) and MgO (7.33%) that promote formation of high-melting silicates (K2MgSiO4, K2Ca2Si2O7, CaSiO3). In contrast, WSA with lower CaO (4.92%) and MgO (2.82%) tends to form low-melting potassium silicates. At high temperatures, both slags are typical crystalline slags, with viscosity rising sharply below a critical temperature. For CSA, rapid nucleation and coarsening of silicate crystals (e.g., KAlSiO4 grain size increases from 20.5 nm at 1350 °C to 192.9 nm at 1050 °C) cause abrupt viscosity increase. For WSA, a high P2O5 content (10.05%) induces a 'chemical dilution effect', leading to persistent KAlSiO4 during cooling and elevated viscosity, especially at the final cooling stage. This study elucidates how ash chemical composition governs high-temperature phase equilibrium and non-equilibrium kinetics, thereby macroscopically affecting ash fusion and rheological behavior, providing a theoretical basis for deeper understanding of biomass ash high-temperature characteristics.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3866-y
Precise measurement of flight parameters—including angle of attack (AOA), angle of sideslip (AOS), and airspeed—is critical for stabilized control of unmanned aerial vehicles (UAVs) in complex aerodynamic environments. Conventional rigid sensors fail to conform to curved leading edges, disrupting local flow and degrading aerodynamic performance, and are ill-suited for UAV miniaturization. Emerging flexible sensing technologies using hot-film, piezoresistive, or capacitive transduction offer potential solutions. This work presents a flexible pressure-velocity sensing patch developed by Professor Jiang's team at Beihang University. The patch integrates a capacitive differential pressure sensor array and a vector flow sensor, fabricated via a multi-layer polyimide bonding process. The capacitive differential pressure sensor features dual-layer chambers, achieving a resolution of 12 mPa within 0–1 Pa, superior to traditional single-layer designs. The vector flow sensor operates on the calorimetric principle, using a micro-heater and thermistor array to characterize flow velocity and direction. A novel pressure-velocity fusion (PVF) algorithm introduces spanwise velocity (Vz) to decouple AOA and AOS, reducing computational complexity compared to classic three-sensor algorithms. Computational fluid dynamics (CFD) simulations validated the algorithm's reliability under wind tunnel conditions. The sensing patch enables simultaneous measurement of multiple flight parameters with high precision and low computational cost, addressing the limitations of rigid sensors and advancing UAV aerodynamic sensing.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3480-1
Electrochemical nitrate reduction to ammonia (NRA) offers a sustainable route for wastewater denitrification and decentralized ammonia synthesis, but its practical deployment is constrained by sluggish reaction kinetics and the competing hydrogen evolution reaction (HER). Monometallic Cu electrocatalysts, despite favorable nitrate adsorption and tunable electronic structure, exhibit weak H* adsorption, limiting the hydrogen radical-mediated pathway that suppresses HER at low overpotentials. Here, highly dispersed Cu/WO3 heterojunctions supported on carbon fiber were synthesized via carbothermal shock reduction, which reaches ultra-high temperatures within seconds and prevents active-site accumulation. The optimal Cu/WO3 heterojunction achieves an ammonia yield rate of 158.66 μmol h−1 cm−2 and a Faradaic efficiency of 98.27%. Electron paramagnetic resonance and density functional theory calculations reveal a synergistic mechanism: Cu sites preferentially adsorb NO3−, while adjacent WO3 sites accelerate water dissociation to generate hydrogen radicals (H*), which drive the continuous hydrogenation of nitrate to ammonia. This spatial separation of functions promotes the H*-mediated pathway and suppresses HER. The work establishes a heterojunction design strategy for non-precious-metal NRA electrocatalysts, enabling high-rate, high-selectivity ammonia production under mild conditions.