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Under the background of social transformation and space reconstruction, population aging in China is becoming more and more diverse and complex. "Aging before getting rich", a notion in population and economic development, has been a serious threat to sustainable development in China. On the basis of town-and street block-scale data from the Fifth and Sixth National Census in the Yangtze River Delta, we studied spatial distribution characteristics of population aging using global Moran's I and hotspot analysis, and applied the geographical detector technique to explain the spatial heterogeneity of population aging. Several conclusions were drawn. (1) The promotion and replacement of aging coexist. Cluster of aging degree exhibits an increasing trend. Population aging is more severe in suburban areas than urban areas.(2) Migration is the main factor affecting the spatial heterogeneity of population aging. Per capital GDP and road network density are the second most influential factors. By contrast, the relief degree of land surface and the air quality index minimally influence population aging. The mechanisms of aging in various regions are affected by varying development levels. (3) The interaction among social, economic, and environmental factors enhances their effects and, thus, interacting factors have a greater influence on population aging than any single factor. The findings of this study have significant implications for local inhabitants and policy makers to address the population aging challenge in achieving sustainability of society, economy, and environment. will become the highest-aged country in the world [3]. Under the background of social transformation and space reconstruction, the aging of China is becoming more and more complex. "Aging before getting rich" and "demographic dividend disappeared", the notion in population and economic development, has been a serious threat to social sustainable development. On the other hand, an aging acceleration significantly affects the urban structure, urban formation, and land use of a city, all of which bring about new challenges for urban planning, especially with regard to the allocation of adequate facilities for an increasing number of elderly people [4]. Under such a circumstance, the aging issue has become a common and fundamental subject for local inhabitants, scholars, and governments all over the world. In the Yangtze River Delta in 2010, as an important economically developed area, the proportion of individuals who were over 60 years was 10.45%, which was significantly higher than the national average. Meanwhile, the Yangtze River Delta is a core area for rapid urbanization. In 2010, the region's gross domestic product (GDP) increased to 7.07 trillion RMB, accounting for 16.42% of the national total. It is not only an economically developed region but also an area where interaction occurs between nature and humans, which has resulted in various environmental and ecological problems and brought great challenges to regional sustainable development. R...

The properties of bulk manganite, its freshly cleaved (010) surface, and this surface exposed to water monolayers at both low and high coverage and to liquid water at 300 K, are examined using density-functional theory (DFT) by the PW91 density functional as well as using the new PM6 semiempirical electronic-structure method. The bonds between the (010) layers are calculated to be very weak, of average energy -2.7 kcal mol -1 , explaining the ease at which manganite surfaces cleave. Upon cleavage, a surface reconstruction is predicted that produces ferroelectrically ordered surface layers, and the surface manganese atoms are predicted to display different chemical properties depending on the nature of the oxygen atom to which they bind in the subsurface layer. Water is predicted to be only physisorbed to the surface, with this process acting to lift the surface reconstruction. At high water coverage, the differences between the two types of surface manganese atoms are also lost. Simulations at 300 K indicate that less than half of the surface manganese atoms coordinate to the fluid at 300 K while only two-thirds of the manganite oxygen atoms on the outside of the surface coordinate. No dominate liquid structure is found, suggesting that dielectric continuum models may be useful in understanding surface chemistry, but it is clear that water-water rather than water-surface interactions dominate the nature of the interface.