Processes

This study establishes a multi-scale validation framework for Computational Fluid Dynamics (CFD) simulations of building-induced pollutant dispersion, integrating wind tunnel experiments, the CEDVAL benchmark dataset, and field measurements from a thermal power plant that serves as a proxy for nuclear facilities. The RNG k-ε and Large Eddy Simulation (LES) models were evaluated across these validation tiers. Results demonstrate that both models effectively capture key flow characteristics, with LES showing superior performance in predicting roof-level velocity and turbulence intensities. A systematic overestimation of rooftop and leeward concentrations was observed, though predictive accuracy improved with downwind distance (e.g., FAC2 > 0.5). The RNG k-ε model provided the best balance between accuracy and computational efficiency for engineering applications, while LES is recommended for high-fidelity near-field analysis. This work provides validated methodologies for environmental risk assessment in nuclear power planning and emission control strategy development.

The stable operation of a rolling mill is crucial for the extremely thin strip rolling process. Moreover, the performance of the rolling mill directly dictates the quality of the extremely thin strip products. In view of the lack of research on the digital twin model and condition monitoring of twenty-high rolling mills, this paper takes the Sendzimir 280 mm twenty-high reversible rolling mill, an extremely thin strip rolling equipment, as the research object, and conducts digital twin modeling and visualization design for it. First and foremost, finite element analysis and vibration analysis were conducted on the rolling mill, based on which the finite element model and dynamics model of the twenty-high rolling mill were established. Secondly, through a comparison between the vibration data of the rolling mill obtained from simulation and those of the physical rolling mill, the accuracy of the simulation model was validated. Finally, a digital twin model of the rolling mill was constructed based on the finite element model and the dynamics model, and the digital twin model of the rolling mill was built using Unity (version 2022.3.57, Unity Technologies, San Francisco, CA, USA) software to complete the visualization design of the digital twin model. The results show that the digital twin platform of the rolling mill established in this paper achieves a high degree of similarity between the virtual rolling mill and the physical one, which proves the effectiveness of the platform and can meet the actual engineering requirements.

This study aimed to enhance the extraction efficiency and elucidate the mechanism of ultrasound-assisted extraction (UAE) of taxanes from Taxus chinensis by natural deep eutectic solvents (NADES). The processes of kinetics and thermodynamics were systematically investigated. These extractions adhered to a pseudo-second-order kinetic model (R² > 0.972), with intraparticle diffusion identified as the dominant mechanism. Key parameters such as temperature, ultrasonic power, and solid/liquid ratio significantly improved the effective diffusion coefficient (D_e) and mass transfer coefficient (K_T), reaching values of 6.21 × 10⁻⁹ m²/s and 4.14 × 10⁻³ m/s, respectively. A high Biot number (B_i > 59.21) confirmed that internal diffusion is the rate-determining step. Thermodynamic analysis indicated that the process is endothermic (ΔH > 0), irreversible (ΔS > 0), and spontaneous (ΔG < 0). These results elucidate the underlying mechanisms of UAE and establish a foundational framework for its industrial-scale implementation.