In the past ten years, carbon dots‐decorated, carbon‐based, metal‐free catalysts (CDs‐C‐MFCs) have become the fastest‐growing branch in the metal‐free materials for energy storage field. However, the further development of CDs‐C‐MFCs needs to clear up the electronic transmission mechanism rather than primarily relying on trial‐and‐error approaches. This review presents systematically and comprehensively for the first time the latest advances of CDs‐C‐MFCs in supercapacitors and metal–air batteries. The structure–performance relationship of these materials is carefully discussed. It is indicated that carbon dots (CDs) can act as the electron‐rich regions in CDs‐C‐MFCs owing to their unique properties, such as quantum confinement effects, abundant defects, countless functional groups, etc. More importantly, specific doping can effectively modify the charge/spin distribution and then facilitate electron transfer. In addition, present challenges and future prospects of the CDs‐C‐MFCs are also given.

Since entering the 'Millennium of the cities' omnipresent rapid urbanization has caused dramatic changes to ecosystem functions and generated huge ecological risks across city catchments. An understanding of how multiple ecosystem services are associated across complex social-ecological systems is required for urban sustainability. However, few studies have explored how the tradeoffs and synergies of ecosystem service response to the traits of urbanization processes such as the variation of undevelopeddeveloped continuum. In this study, we took the Yangtze River Delta in China, a typical megapolis, as the case study area and quantified seven ecosystem services at a 10km x 10km spatial scale. We presented the spatial distribution and interactions of these services and identified whether they coexist in the form of specific cluster types. We found positive spatial autocorrelations across the study site. A significant tendency of trade-offs was detected between regulating and agricultural provisioning services, and we also spotted the possibility of both trade-offs and synergies that regulating and (different) cultural services were able to provide. Our results identified four different cluster types, and the cluster distributions are strongly associated with the urbanization levels -a tendency for urbanizing areas to witness the function shift in the certain order of 'ecology -provision -multifunction -accessibility'. This provides a deeper understanding of the interactions among multiple ecosystem services and how they were determined by the ongoing social-ecological influences. The close connection between urbanization processes and ecosystems interact across developing and developed areas should be taken into consideration for future landscape planning.

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Dynamics of leaf area index and canopy openness of three forest types in a warm temperate zone E Higher Education Press and Springer-Verlag 2008Abstract Deciduous broad-leaved forests (DBF), Larix principis-rupprechtii (LF) and Pinus tabulaeformis plantations (PF) are three typical forest communities in the warm temperate zone of the Dongling Mountains. In this study, we used an indirect method, hemispheric photography, to measure and analyze the dynamics of leaf area index (LAI) and canopy openness of the three forest communities. The results show that the LAI values of DBF and LF increased gradually with plant growth and development. The highest LAI value appeared in August, while canopy openness changed inversely with LAI. The lowest value appeared in November. DBF maintained a higher LAI in August and had a more open canopy in November compared with LF. For PF, we observed little changes in the LAI and canopy openness which was attributed to the leaf retention of this evergreen species. However, a similar relation between LAI and canopy openness was found for the three forest communities: canopy openness varied inversely with LAI. The relation is exponential and significant. Therefore, canopy openness is a good indicator of LAI in forests. This result can be used to test the validity of the LAI based on remote sensing and to provide a reference for the study of the canopy heterogeneity and its effect. This also benefits modeling for fluxes of carbon, water and energy from the level of the stand to landscape.