Understanding hydrological effects of ecological restoration (ER) is fundamental to develop effective measures guiding future ER and to adapt climate change in China's Loess Plateau (LP). Streamflow (Q) is an important indicator of hydrological processes that represents the combined effects of climatic and land surface conditions. Here 14 catchments located in the LP were chosen to explore the Q response to different driving factors during the period 1961-2009 by using elasticity and decomposition methods based on the Budyko framework. Our results show that (1) annual Q exhibited a decreasing trend in all catchments (20.30 $ 21.71 mm yr 22 ), with an average reduction of 20.87 mm yr 22 . The runoff coefficients in flood season and nonflood season were both decreasing between two periods divided by the changing point in annual Q series; (2) the precipitation (P) and potential evapotranspiration (E 0 ) elasticity of Q are 2.75 and 21.75, respectively, indicating that Q is more sensitive to changes in P than that in E 0 ; (3) the two methods consistently demonstrated that, on average, ER (62%) contributing to Q reduction was much larger than that of climate change (38%). In addition, parameter n that entails catchment characteristics in the Budyko framework showed positive correlation with the relative area of ER measures in all catchments (eight of them are statistically significant with p < 0.05). These findings highlight the importance of ER measures on modifying the hydrological partitioning in the region. However, ER actions over the sloping parts of the landscape weakened the impact of those in channels (i.e., check-dams) on Q, especially after the implementation of the Grain-for-Green project in 1999.

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Graphene quantum dots (GQDs) as new 0dimensional (0D) materials have exhibited promising applications in numerous fields, and these enormous potentials are largely dependent on their electronic properties. Herein we tailored the semiconductive behavior of GQDs and transformed the n-type hydrothermally synthesized GQDs to p-type via the modification of PO groups with an electron-withdrawing ability. The obtained highly dispersed and stable P-doped GQDs (P-GQDs) had uniform size and thickness, high crystallinity, and wide visiblelight absorption region. The subsequent assembly with the n-type graphitic carbon nitride (CN) formed a stable metal-free photocatalyst because of the π−π interaction between conjugated GQDs sheets and CN layers and the possible hydrogen bonds as well. Due to the formation of p−n junction on the P-GQDs/CN interface, the photogenerated charges were efficiently separated which resulted in an enhanced photocatalytic performance. This strategy illuminates the GQDs applications by controlling the electronic structure of GQDs based on the detailed application, not only for photocatalysis but also for many other fields such as solar cells, catalysis, electrocatalysis, and so on.

Context Human demands for ecosystem services (ES) have tremendously changed the landscape and led to degradation of ecosystems and associated services. The resolving of current eco-environmental problems calls for better understanding of the spatially explicit ES interactions to guide targeted landuse policy-making. Objectives We propose a framework to map ES in continuous time-series, based on which we further quantify interactions among multiple ES. Methods The supply of three key ES-soil conservation (SC), net primary production (NPP) and water yield (WY)-were quantified and mapped at fineresolution from 2000 to 2013 using easily-accessible spatial data. Pairwise ES interactions were quantified using a spatio-temporal statistical method. Results Spatio-temporal analyses of ES dynamics illustrated that the supply of the three ES increased over the past 14 years in northern Shaanxi, where land cover dramatically changed owing to the wide-range ecological restoration projects. Our results also revealed that ES interactions varied across locations due to landscape heterogeneity and climate difference. In the arid and semi-arid area, synergies among ES (e.g., SC vs. WY) tended to dominate in grassland, while in artificial lands ES were prone to show tradeoffs. In the semi-humid area, pairwise ES (e.g., NPP vs. WY) in woodland tended to present synergies. Conclusions The spatio-temporal variation of ES and their interactions resulted from coupling effect of human-induced climate and land-use change. In the long-term, spatially explicit quantification of ES Electronic supplementary material The online version of this article (