Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202507062
The construction of predictive models for the recurrence of blackening and odor in urban water bodies has become a critical foundation for refined management of urban water environments. Based on water quality monitoring data from 16 cities in the Yangtze River Basin from 2020 to 2023, this study systematically evaluated six typical comprehensive index calculation methods and proposed a probabilistic prediction model for water blackening and odor recurrence centered on the VIKOR composite index. Through sampling analysis and literature review, a power-law relationship between transparency (y) and turbidity (x) was established (y = 3.12x−0.66), leading to a critical turbidity threshold of 46.9 NTU for blackening and odor. Using ANOVA, recursive feature elimination, and random forest, five indicators—turbidity, dissolved oxygen (DO), total phosphorus (TP), permanganate index (CODMn), and ammonia nitrogen (NH3-N)—were selected as the model's indicator system, with importance ranking: turbidity > DO > TP > CODMn > NH3-N. The VIKOR composite index exhibited the most robust mapping relationship with blackening probability, achieving high accuracy (RMSE = 0.029, MAE = 0.020) and consistency (NSE = 0.918, R2 = 0.918), whereas models based on other indices yielded R2 values below 0.84. The model demonstrated good predictive performance across the Yangtze, Pearl, Haihe, and Yellow River basins. This model offers a universal decision-making tool for precise identification, early warning, and targeted management of water blackening and odor recurrence, with potential integration into urban water smart platforms.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3889-6
Photocatalytic hydrogen production is fundamentally limited by inefficient charge separation and asynchronous supply of electrons and protons to active sites. Here, we designed a ZnIn2S4/ZnCo2S4 (ZIS/ZCS) heterojunction with an atomically coherent interface achieved via an ultralow lattice mismatch of 0.05%. This unique structure promotes rapid electron transfer through a built-in electric field and facilitates continuous proton migration via a hydrogen spillover effect, thereby synchronizing electron and proton delivery at the catalytic interface. This dual regulation of electrons and protons synergistically promotes proton-coupled electron transfer, resulting in a high hydrogen evolution rate of 70.3 mmol g−1 h−1 and selective oxidation of benzyl alcohol to aldehyde (39.3 mmol g−1 h−1) with 93.6% selectivity. This work demonstrates the critical importance of lattice match and dual charge-proton management in designing efficient photocatalysts for complex redox reactions.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3825-x
Polymer-based dielectric materials with high energy density and thermal stability are critical for modern electric/electronic industries. Polyimide (PI) based materials are promising due to their high temperature resistance and chemical inertness, yet their inherently low dielectric constant and limited charge-discharge energy density restrict applications in film capacitors. While incorporating ferroelectric or conductive fillers can enhance dielectric performance, batch-to-batch inconsistency and physical deterioration remain problematic. This study focuses on molecular structure design and modulation, preparing hyperbranched polyimides with different dianhydride monomers and branching degrees. The effects of chain packing density with polar groups on dielectric and energy storage performances were systematically investigated via experimentation and molecular simulation. Results demonstrate a significant correlation between monomers' electrical distribution and packing density in polymer systems. Molecular simulation further elucidated the underlying mechanism. This work establishes a foundation for designing polymer-based dielectric materials with high dielectric and energy storage performances at the molecular level.