RESUMEN
Regional habitat quality is an important reflection of ecosystem services and ecosystem health. Exploring the characteristics of habitat quality changes and revealing the vulnerability of regional ecosystems caused could provide reference for the improvement of ecological service functions and the protection of regional ecological environment. Based on remote sensing data of Shaanxi Province from 2000 to 2015, InVEST model and grid analysis were used to analyze the evolution characteristics of habitat quality and landscape pattern, and spatial autocorrelation was also used to analyze the spatial correlation and temporal evolution characteristics. The results showed: (1) Arable land, grassland, and forest land were the main landscape types in Shaanxi province, accounting for more than 94% of the total area, and the arable land and unused land showed a decreasing trend, while the grassland and forest land showed an increasing trend, and the proportion of construction land continued to increase with the rapid economic development from 2000 to 2015; (2) The spatial distribution characteristics of habitat quality was similar to land use cover change, which was "high in the southern and central forest areas, low in the northern sandy land and central urban agglomeration", and habitat quality value showed a steady increase, indicating that the habitat quality was getting better; (3) The landscape pattern index values of Guanzhong Plain urban agglomeration changed significantly, which tended to be fragmented, and the landscape types were more diverse and uniform; (4) There were obvious spatial correlation between habitat quality and landscape pattern, and the spatial differentiation of clustering was obvious, and the clustering effect of habitat quality and landscape pattern characteristics would weaken with the increase in urbanization degree. The analysis of the spatial association between habitat quality and landscape pattern could provide scientific support for ecological protection and landscape planning.
RESUMEN
Freezing of water and melting of ice at the nanoscale play critical roles in science and technology fields, including aviation systems, infrastructures, and other broad spectrum of technologies. To cope with the icing challenge, nanoscale anti-icing surface technology has been developed. The freezing and melting temperatures can be tailored by manipulating the size (the radius of water or ice); however, it lacks systemic research. In this work, the size effect on the melting temperature of ice nanocrystals was first established, which considered the variation of bond energy and equivalent heat energy from the perspective of the force-heat equivalence energy density principle. Based on the heterogeneous nucleation mode and by further considering the size and temperature effects on the interface energy involved solid-liquid energy and liquid-vapor energy as well as the above developed melting temperature model, another model is established to accurately predict the freezing temperature of water nanodroplets. The parameters required by the two models established in this paper have a clear physical meaning and establish the quantitative relationships among freezing temperature, melting temperature, surface stress, interface energy, and other thermodynamic parameters. The agreement between model prediction and experimental simulation data confirms the validity and universality of the established models. The higher prediction accuracy of this work compared to the other theoretical models, due to the more detailed consideration and the reference point, captures the errors introduced by the experiment or simulation. This study contributes to a deeper understanding of the underlying mechanism of freezing of water and melting of ice nanocrystals and provides theoretical guidance for the design of cryopreservation systems and anti-icing systems for aviation.
