In recent decades, with the rapid development of the inorganic synthesis and the increasing discharge of pollutants in the process of industrialization, hollow-structured metal oxides (HSMOs) have taken on a striking role in the field of environmental catalysis. This is all due to their unique structural characteristics compared to solid nanoparticles, such as high loading capacity, superior pore permeability, high specific surface area, abundant inner void space, and low density. Although the HSMOs with different morphologies have been reviewed and prospected in the aspect of synthesis strategies and potential applications, there has been no systematic review focusing on the structures and compositions design of HSMOs in the field of environmental catalysis so far. Therefore, this review will mainly focus on the component dependence and controllable structure of HSMOs in the catalytic elimination of different environmental pollutants, including the automobile and stationary source emissions, volatile organic compounds, greenhouse gases, ozone-depleting substances, and other potential pollutants. Moreover, we comprehensively reviewed the applications of the catalysts with hollow structure that are mainly composed of metal oxides such as CeO₂, MnO_x, CuO_x, Co₃O₄, ZrO₂, ZnO, Al₃O₄, In₂O₃, NiO, and Fe₃O₄ in automobile and stationary source emission control, volatile organic compounds emission control, and the conversion of greenhouse gases and ozone-depleting substances. The structure–activity relationship is also briefly discussed. Finally, further challenges and development trends of HSMO catalysts in environmental catalysis are also prospected.

This study first employs TurbSim and OpenFAST (Fatigue, Aerodynamics, Structures, Turbulence) programs for secondary development to comprehensively model the NREL-5MW semi-submersible wind turbine and OC4-DeepC wind floating platform with wind–wave interaction. Next, we investigate the dynamic response of floating wind turbines under the complex coupling of turbulent winds and irregular waves. Turbulent wind fields were simulated using the IEC Kaimal model with turbulence intensities of 5% and 20%. Additionally, two irregular waves were simulated with the Pierson–Moskowitz (P–M) spectrum. The results indicate that in turbulent wind conditions, the aerodynamic power of the wind turbine and the root bending moments of the blades are significantly influenced by turbulence, while the impact of waves is minimal. The coupled motion response of the floating platform demonstrates that turbulence intensity has the greatest impact on the platform’s heave and pitch motions, underscoring the importance of turbulence in platform stability. This study provides essential insights for designing and optimizing floating wind turbines in complex wind–wave coupling offshore environments.

The air flow and pollutant concentration fields in a street canyon affected by trees could affect the comfort and health of residents. At present, the description of the non-uniform/discontinuous distribution of leaves is difficult. In this study, the leaf distribution in the canopy was characterized by establishing non-continuous (uniform/random) algorithm based on a numerical simulation method, and the effects of canopy properties including, height, porosity and uniform/random leaf distribution, on the airflow and pollutant concentration fields in urban street canyons were investigated. The position of the tree canopy was found to directly affect the airflow field form and the air velocity distribution in the street canyon at low inflows. The average air velocity in the street canyon could be reduced significantly when the top of the tree canopy is near the top of the street canyon. The air velocity and pollutant concentration in the street canyon would vary only slightly due to the canopy porosity. Due to the increasing canopy porosity, the air velocity would increase, and the pollutant concentration would be reduced. The leaves are non-continuous and uniformly distributed at constant porosity, which does not significantly change the velocity distribution and pollutant concentration in the street canyon.

During the expansion of a wind farm, the strategic placement of wind turbines can significantly improve wind energy utilization. This study investigates the evolution of wake turbulence in a wind farm after introducing smaller wind turbines within the gaps between larger ones, focusing on aspects such as wind speed, turbulence intensity, and turbulence integral length scale. The flow field conditions are described using parameters like turbulence critical length and power spectral density, as determined through wind tunnel experiments. In these experiments, a single large wind turbine model and nine smaller wind turbine models were used to create a small wind farm unit, and pressure distribution behind the wind turbines was measured under various operating conditions. The results indicate that downstream wind speed deficits intensify as the number of small wind turbines in operation increases. The impact of these smaller turbines varies with height, with a relatively minor effect on the upper blade tip and increasingly adverse effects as you move from the upper blade tip to the lower blade tip. Through an analysis of power spectral density, the contribution of vortex motion to wake turbulence kinetic energy is further quantified. In the far wake region, the number of small wind turbines has a relatively small impact on wind speed fluctuations.

Tree is an essential factor affecting airflow and pollutant diffusion in the urban street canyon. The wind environment in the urban street canyon will be effectively improved by expounding the mechanism and implementing greening measures. Moreover, it will help decrease the pollutant concentration around the street canyon. This paper reviews the airflow and pollutant diffusion numerical simulation in the street canyon under the tree influence. Firstly, the numerical mathematical model used for pollutant diffusion and airflow in urban street canyons under the influence of trees is summarized. The representation of trees’ numerical mathematical model in the simulation domain is mainly proposed. Secondly, the wind environment and pollutant distribution factors influencing urban street canyons are elaborated and analyzed, including tree characteristics, layout, street canyon shape, and thermal. Furthermore, current research progress and deficiencies are discussed. Finally, the future research direction of wind environment and pollutant distribution simulation in urban streets under the influence of trees is pointed out.

Power plants remain major contributors to air pollution, and while their impact on air quality and atmospheric chemistry have been extensively studied, there are still uncertainties in quantifying their precise contributions to PM_2.5 and O₃ formation under varying environmental conditions. This study employs the WRF/CMAQ modeling system to quantify the impact of power plant emissions on PM2.5 and O₃ levels across eastern China in June 2019. We investigate the spatial and temporal patterns of pollutant formation, analyze contributions to secondary PM2.5 components, and assess process-specific influences on O₃ concentrations. Results show that power plant emissions contribute up to 2.5–3.0 μg m⁻³ to PM_2.5 levels in central and eastern regions, with lower impacts in coastal and southern areas. O₃ contributions exhibit a more complex pattern, ranging from −4 to +4 ppb, reflecting regional variations in NOx saturation. Among secondary PM_2.5 components, nitrate formation is most significantly influenced by power plant emissions, emphasizing the critical role of NOx. Diurnal O₃ patterns reveal a transition from widespread morning suppression to afternoon enhancement, particularly in southern regions. Process analysis indicates that vertical transport is the primary mechanism enhancing surface O₃ from power plant emissions, while dry deposition acts as the main removal process. This comprehensive assessment provides crucial insights for developing targeted air quality management strategies, highlighting the need for region-specific approaches and prioritized NOx emission controls in the power sector. Our findings contribute to a deeper understanding of the complex relationships between power plant emissions and regional air quality, offering a foundation for more effective pollution mitigation policies.