Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2024112102
Based on the 2022 activity data of non-road mobile sources in Hebei Province, this study employed the emission factor method recommended by the Guidelines to estimate emissions of CO, HC, NOx, PM2.5, PM10, and SO2. A comprehensive emission inventory was established, followed by spatial and uncertainty analyses. Scenario analysis, aligned with the 14th Five-Year Plan policies, was used to project emissions for 2030. The results indicate that non-road mobile sources in Hebei emitted 76.1×10^3 t of CO, 20.6×10^3 t of HC, 164.0×10^3 t of NOx, 8.5×10^3 t of PM2.5, 9.0×10^3 t of PM10, and 2.4×10^3 t of SO2. Agricultural machinery was the dominant contributor to CO, HC, PM2.5, and PM10, accounting for over 60.0% of CO emissions. Railway locomotives were the primary source of NOx, contributing 50.9%. For SO2, agricultural machinery and railway locomotives contributed 39.0% and 44.4%, respectively. The highest emitting cities were Tangshan (21.3%), Shijiazhuang (15.7%), Cangzhou (11.6%), and Handan (11.6%). Ship emissions were concentrated in Tangshan Port; civil aviation emissions were mainly in Shijiazhuang, Tangshan, Qinhuangdao, and Handan; railway emissions were distributed in Shijiazhuang, Baoding, and Handan. Under the updated emission standard scenario, NOx and PM10 emissions in 2030 could be reduced by approximately 35.0%. The phase-out of old machinery yielded the largest reduction in CO (36.0%), while both electrification and phase-out scenarios significantly impacted HC emissions.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4098-8
Fluorescence image-guided photodynamic therapy (PDT) enables real-time monitoring of photosensitizer biodistribution and metabolism for optimized treatment timing. However, its application remains limited by reliance on high-end imaging systems. To address this, we designed three novel small-molecule photosensitizers (TTNb, TTAn, TTPh) based on a 2-vinylbenzoic acid scaffold, functionalized at the 5-position with nitro, amino, or hydrogen groups. Replacing the nitro group with amino or hydrogen switched aggregation behavior from aggregation-induced emission (AIE) to aggregation-caused quenching (ACQ), accompanied by a red-to-green fluorescence shift and subcellular relocation from liposomes to lysosomes. These findings establish design principles for ratiometric nitroreductase probes and enable systematic comparison between AIE and ACQ photosensitizers. Among these, TTAn exhibited superior cellular uptake (2800 times higher than Ce6 in Eca-109 cells), specific lysosomal targeting, balanced reactive oxygen species (singlet oxygen/superoxide anion) generation, and intense fluorescence. Under white light irradiation, TTAn achieved an IC50 of 21 nM, surpassing Ce6 by 50-fold. Notably, TTAn produced strong fluorescence in mice tumors under both one- and two-photon excitation, detectable using conventional imaging tools (smartphones, DSLR cameras) or even visible to the naked eye, confirming outstanding tumor specificity. Leveraging these advantages, TTAn enabled successful image-guided two-photon PDT in Eca-109 tumor-bearing mice with a single treatment, demonstrating potent therapeutic efficacy and biosafety. This work provides a strategic blueprint for developing small-molecule theranostic agents that operate without complex fluorescence imaging systems.