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This study investigated the content, distribution, and contamination levels of toxic metals (Cd, Cr, Cu, Pb, and Zn) in street dust in Lanzhou, an industrial city in Northwest China. Meanwhile, the risk these metals posed to the urban ecosystem and human health was also evaluated using the potential ecological risk index and human exposure model. Results showed that concentrations of these metals in the dust are higher than the background value of local soil, with Cu having the highest levels. The districts of Anning and Xigu had the most extreme levels of contamination, while Chengguan and Qilihe districts were lightly contaminated, which can be partly attributed to human activities and traffic densities. In comparison with the concentrations of selected metals in other cities, the concentrations of heavy metals in Lanzhou were generally at moderate or low levels. Heavy metal concentration increased with decreasing dust particle size. The pollution indices of Cr, Cd, Cu, Pb, and Zn were in the range of 0.289–2.09, 0.332–2.15, 1.38–6.21, 0.358–2.59, and 0.560–1.83 with a mean of 1.37, 1.49, 3.18, 1.48, and 0.897, respectively. The geo-accumulation index (Igeo) suggested that Zn in street dust was of geologic origin, while Cd, Cr, Pb, and Cu were significantly impacted by anthropogenic sources. The comprehensive pollution index showed that urban dust poses a high potential ecological risk in Lanzhou. Non-carcinogenic and carcinogenic effects due to exposure to urban street dust were assessed for both children and adults. For non-carcinogenic effects, ingestion appeared to be the main route of exposure to dust particles and thus posed a higher health risk to both children and adults for all metals, followed by dermal contact. Hazard index values for all studied metals were lower than the safe level of 1, and Cr exhibited the highest risk value (0.249) for children, suggesting that the overall risk from exposure to multiple metals in dust is low. The carcinogenic risk for Cd and Cr was all below the acceptable level (< 10−6).

Coal blending in thermal power plants is a complex multi-objective challenge involving economic, operational and environmental considerations. This study presents a Q-learning-enhanced NSGA-II (QLNSGA-II) algorithm that integrates the adaptive policy optimization of Q-learning with the elitist selection of NSGA-II to dynamically adjust crossover and mutation rates based on real-time performance metrics. A physics-based objective function takes into account the thermodynamics of ash fusion and the kinetics of pollutant emission, ensuring compliance with combustion efficiency and NO x limits. Benchmark tests on the Walking Fish Group (WFG) and Unconstrained Function (UF) suites show that QLNSGA-II achieves a 12.7% improvement in Inverted Generational Distance (IGD) and a 9.3% improvement in Hypervolume (HV) compared to prevailing algorithms. Industrial validation at the Huaneng Yingkou power plant confirms a 14.7% reduction in fuel cost and a 41% reduction in slagging incidence over conventional blending methods, backed by 12 months of operational data. Other benefits include a 24.8% reduction in sulphur content, a 6.9% increase in the plant’s net heat rate and annual savings of RMB 12.3 million, 2,150 tonnes of limestone and 38,500 tonnes of CO 2 -equivalent emissions. These results highlight QLNSGA-II as a scalable, robust solution for multi-objective coal blending, offering a promising way to improve the efficiency and sustainability of coal-fired power generation.

In this paper, carbon coated spherical Mn3O4 was prepared by decomposition of spherical MnCO3 and sucrose. The results of XRD and SEM showed that Mn3O4/C composites are sphere-like with good crystallinity, and its diameter is about 1um. It could deliver a reversible charge capacity of 848.7 mA h g-1 at the current density of 162.3 mA g-1, and the specific discharge capacity is still have 441 mA h g-1 at a high current density of 649.4 mA g-1 exhabiting good rate performance. The excellent performance of the spherical Mn3O4/C composites could be attributed to its unique architecture which provides fast lithium ion and electron transportation as well as accommodates the large volume change of transition metal oxides during conversion reactions.

The emergence of quantum metallic state marked by a saturating finite electrical resistance in the zero-temperature limit in a variety of two-dimensional superconductors injects an exciting momentum to the realm of heterostructure superconductivity. Despite much research efforts over last few decades, there is not yet a general consensus on the nature of this unexpected quantum metal. Here, we report the observation of a unique quantum metallic state within the hallmark of Bose-metal in the titanium sesquioxide heterointerface superconductor Ti\\(_2\\)O\\(_3\\)/GaN. Remarkably, the quantum bosonic metallic state continuously tuned by a magnetic field in the vicinity of the two-dimensional superconductivity-metal transition persists in the normal phase, indicating the existence of composite bosons formed by electron Cooper pairs even in the normal phase. Our findings provide a distinct evidence for electron pairing in the normal phase of heterointerface superconductors, and shed fresh light on the pairing nature underlying heterointerface superconductivity.

The coexistence of superconductivity and ferromagnetism is a long-standing issue in superconductivity due to the antagonistic nature of these two ordered states. Experimentally identifying and characterizing novel heterointerface superconductors that coexist with magnetism presents significant challenges. Here, we report the experimental observation of two-dimensional long-range ferromagnetic order in the KTaO\\(_3\\) heterointerface superconductor, showing the coexistence of superconductivity and ferromagnetism. Remarkably, our direct current superconducting quantum interference device measurements reveal an in-plane magnetization hysteresis loop persisting above room temperature. Moreover, the first-principles calculations and X-ray magnetic circular dichroism measurements provide decisive insights into the origin of the observed robust ferromagnetism, attributing it to oxygen vacancies that localize electrons in nearby Ta 5\\(d\\) states. Our findings not only suggest KTaO\\(_3\\) heterointerfaces as time-reversal symmetry breaking superconductors, but also inject fresh momentum into the exploration of the intricate interplay between superconductivity and magnetism, enhanced by the strong spin-orbit coupling inherent to the heavy Ta in 5\\(d\\) orbitals of KTaO\\(_3\\) heterointerfaces.