RESUMEN
Solar desalination is one of the most promising strategies to address the global freshwater shortage crisis. However, the residual salt accumulated on the top surface of solar evaporators severely reduces light absorption and steam evaporation efficiency, thus impeding the further industrialization of this technology. Herein, a metal-phenolic network (MPN)-engineered 3D evaporator composed of photothermal superhydrophilic/superhydrophobic sponges and side-twining hydrophilic threads for efficient desalination with directional salt crystallization and zero liquid discharge is reported. The MPN coatings afford the engineering of alternating photothermal superhydrophilic/superhydrophobic sponges with high heating efficiency and defined vapor escape channels, while the side-twining threads induce site-selective salt crystallization. The 3D evaporator exhibits a high and stable indoor desalination rate (≈2.3 kg m-2 h-1 ) of concentrated seawater (20 wt%) under simulated sun irradiation for over 21 days without the need for salt crystallization inhibitors. This direct desalination is also achieved in outdoor field operations with a production rate of clean water up to ≈1.82 kg m-2 h-1 from concentrated seawater (10 wt%). Together with the high affinity and multiple functions of MPNs, this work is expected to facilitate the rational design of solar desalination devices and boost the research translation of MPN materials in broader applications.
RESUMEN
In recent years, urbanization has been developing rapidly. However, it is also accompanied by land management problems, such as low land use efficiency. In this research, we manage to explore the temporal and spatial evolution laws as well as characteristics of the coupling and coordinated development between urbanization and land use benefits. Through this, it is possible for us to provide policy recommendations for the sustainable development of the urbanization in Fujian Province. In this study, we take prefecture-level municipal districts and county-level cities in Fujian as the research subject. We construct an index system, based on data in 2002, 2005, 2010, 2015, and 2017, to evaluate the urban land use benefits and urbanization. Besides, we leverage the Gini coefficient weighting method to give weight to each index and calculate the value of its benefits. Moreover, it is the relative development degree and the coupling coordination degree model that we comprehensively leverage to study the spatiotemporal evolution law of the coupling coordination degree (CCD). The results show that: (1) Urban land use benefits and urbanization level are positively correlated with the regional administrative level and economic development status; (2) The CCD of urban land use benefits and urbanization level in various regions of Fujian is still low. However, the overall development direction is good; (3) From the perspective of spatial distribution, the CCD owns a "center-periphery" pattern that is based on the law of diminishing CCD power from three central cities of Fuzhou, Xiamen, and Sanming. Consequently, it requires governments to take action. Firstly, they should promote the intensive land use in the urbanization process. Meanwhile, they should also pay attention to ecological environment protection. Besides, it is recommendable to give full play to the radiating and leading effect of central cities on surrounding ones. Finally, they are required to provide appropriate policies and resource support to peripheral cities.