The rapid development of high-speed railway networks requires advanced methods for analysing vibration and sound radiation characteristics of a fast rotating train wheel subject to a vertical harmonic wheel-rail force. In order to consider the rotation of the wheel and at the same time increase the computational efficiency, a procedure is adapted in this paper taking advantage of the axial symmetry of the wheel. In this procedure, a recently developed 2.5D finite element method, which can consider wheel rotation but only requires a 2D mesh over a cross section containing the wheel axis, is used to calculate the vibration response of the wheel. Then, the vibration response of the wheel is taken as acoustic boundary condition and the 2.5D acoustic boundary element method, which only requires a 1D mesh over the boundary of the above cross section, is utilised to calculate the sound radiation of the wheel. These 2.5D methods and relevant programs are validated by comparing results from this procedure with those from conventional 3D analyses using commercial software. The comparison also demonstrates that these 2.5D methods have a much higher computational efficiency. Using the 2.5D methods, we study the wheel rotation speed influences on the factors including the vertical receptance of the wheel at wheel-rail contact point, sound pressure level at a pre-defined standard measurement point, radiated sound power level, directivity of the radiation, and contribution of each part of the wheel. It can be concluded that the wheel rotation speed splits most peaks of the vertical receptance at the wheel-rail contact point, sound pressure levels at the field, and the sound power level of the wheel into two peaks. The directivity and power contribution of the wheel are also significantly changed by the wheel rotation speed. Therefore, the rotation of a train wheel should be taken into account when calculating its vibration and sound radiation.

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In the new era, with the acceleration of the construction of Hainan Free Trade Island, the contradiction between the maintenance of ecological security and the development of urban and rural construction in Sanya has become increasingly prominent. In order to explore the spatial pattern and sustainable development trend of land use in Sanya City in the future, this study uses the GeoSOS-FLUS model as the main model, ENVI remote sensing image interpretation and ArcGIS spatial analysis as the supplement, and Fragastas landscape pattern index analysis as the supplement to realize the spatial layout simulation and diversity evaluation of land use in Sanya City in the future. The land use circulation trend, fragmentation trend and diversity trend in Sanya from 2017 to 2025 were analyzed, and the regulation and guidance strategies of land use were discussed from three aspects of land space planning control, land landscape pattern control and land use circulation control. The results show that under the strict land use conversion restrictions, the degree of fragmentation of the land system in Sanya is generally decreased, and it maintains a relatively stable integrity, diversity and uniformity of the land system.

To precisely clarify the eco-environment quality status of the Tropical Rainforest National Park, this study develops and validates an eco-environmental quality index (EQI) model applicable to the evaluation of the eco-environment quality of the Tropical Rainforest National Park by using the Google Earth Engine (GEE) as a platform, based on the RSEI model, and applying standardized processing of indicators, artificial correction of PCA eigenvectors, and stepwise regression analysis modeling. And the EQI change trends, change processes, and spatial distribution of significant changes in the Tropical Rainforest National Park are analyzed at two different levels, namely dynamic changes in ecological environmental quality and spatial identification of time series changes, respectively. We also investigate the effects of factors such as the model's internal indicators, topographical elements, and the distribution of land use cover types on the changes in EQI. The results indicate that: 1) The application of the EQI4 model could invert the EQI spatial distribution map consistent with the RSEI model, and the overall change of EQI in tropical rainforest national parks estimates using the EQI4 model reveals a stable and slightly decreasing trend with obvious process volatility. 2) The Tropical Rainforest National Park's EQI spatial distribution and fluctuation zoning has shown obvious spatial heterogeneity. The proportion of spatial area with significant changes in EQI increases as the study time series progress, and the deterioration trend of its time series EQI is the most pronounced in the two regions represented by Jianfengling and Diaoluoshan. (3) The distribution of EQI coefficients of variation in Tropical Rainforest National Park is in excellent agreement with those of NDVI and WET, as measured by R2 values of 0.69 and 0.79, respectively. The bivariate clustering of EQI coefficients of variation with topographic elements reveals that low-elevation, gently sloping areas with frequent human activities, and forest cash crop cultivation areas have greater EQI fluctuations. Consequently, timely, accurate, and rapid quantitative assessment and spatial and temporal change analysis of the eco-environmental quality of Tropical Rainforest National Park can promote the protection of natural resources and ecologically sustainable development of the national park.