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Birch Ho posted an update 6 months, 1 week ago
With more record-breaking skyscrapers built in big cities around the world, horizontal urban sprawl no longer dominates the research of urbanization rather than the vertical growth of cities. In such a context, the urban heat island problem cannot be understood by solely studying the impact of the horizontal urban expansion because the 3D structure of the urban landscape could severely alter the natural heat flux transport over the land surface and thus lead to bigger heat island problems. In addition to our current knowledge of impact of 2D landscape changes on urban thermal dynamics, it is crucial to understand the effects of 3D landscape pattern on the thermal environment, in order to maintain a sustainable and eco-friendly urban development. This study investigated the 2D/3D landscape pattern metrics and their association with the land surface temperature (LST) changes in a case study area of Shanghai City using the extreme gradient boosting (XGBoost) regression model and Sharpley Additive exPlanations (SHAP) interpretation method based on datasets of land cover and digital surface model (DSM). Major findings include, 1) 3D landscape pattern metrics could better describe the undulation and heterogeneity of urban surface and were essential when explaining the variation of LST compared with conventional 2D landscape pattern metrics, 2) Low-rise and high-rise buildings tend to alleviate LST while buildings with medium height heating the surroundings; 3) the cooling effect of vegetation was significantly strong; 4) different urban functional types impact the surface temperature in the way determined by their 3D urban landscape pattern. These findings may help urban planners and landscape designers achieve the goal of minimizing urban heat island using computer models of 3D urban structure. Humic substances, especially humin (HM) in its solid phase, is considered to be the main electron donor during the reduction of Cr(VI) in the environment. This work explores the reaction mechanism between Cr(VI) and the functional groups contained in HM, environmentally persistent free radicals (EPFRs), and reactive oxygen species (ROS). We examine the changes in the functional groups, EPFRs, and ROS on HM during the reaction, and inhibit the production of ROS to verify their effect. Our results demonstrate that the carboxyl and phenolic hydroxyl groups contained in HM are consumed during the reaction. The phenolic hydroxyl group can directly react with Cr(VI) as an electron donor, and can also transfer electrons to molecular oxygen to generate superoxide radicals to reduce Cr(VI). EPFRs also exhibit the same reaction pathway. The molecular oxygen in the solution gains electrons to generate O2·-, which further reacts with Cr(VI) to reduce it to Cr(III). The production and effect of active oxygen are verified by removing oxygen from the solution. In this study, the contribution of active oxygen to the reduction of Cr(VI) is approximately 30%. 5-HT research buy This study provides theoretical support for revealing the effects of humic substances on the conversion of Cr(VI). Ocean acidification will likely change the structure and function of coastal marine ecosystems over coming decades. Volcanic carbon dioxide seeps generate dissolved CO2 and pH gradients that provide realistic insights into the direction and magnitude of these changes. Here, we used fish and benthic community surveys to assess the spatio-temporal dynamics of fish community properties off CO2 seeps in Japan. Adding to previous evidence from ocean acidification ecosystem studies conducted elsewhere, our findings documented shifts from calcified to non-calcified habitats with reduced benthic complexity. In addition, we found that such habitat transition led to decreased diversity of associated fish and to selection of those fish species better adapted to simplified ecosystems dominated by algae. Our data suggest that near-future projected ocean acidification levels will oppose the ongoing range expansion of coral reef-associated fish due to global warming. V.Regions at high latitudes and high altitudes are undergoing a more pronounced winter warming than spring warming, and such asymmetric warming will affect chilling and forcing processes and thus the spring phenology of plants. We analyzed winter chilling and spring forcing accumulation in relation to the spring phenology of three tree species (Ulmus pumila, Populus simonii, and Syringa oblata) growing in a cold region (CR) compared with trees in a warmer reference region (WR), using the Dynamic Model and the Growing Degree Hour (GDH) model. We tested that forcing rather than chilling affects the spring phenology of trees in CR (hypothesis I), and that trees in CR have both lower mean chilling and forcing temperature and thus longer accumulation periods than trees in WR (hypothesis II). The modeling results confirmed that chilling and forcing occur simultaneously during the early spring when temperature gradually increases. In line with our hypotheses, forcing played a crucial role in spring phenology in CR, but chilling and forcing combined to determine spring phenology in WR. The temperature during the chilling and forcing periods was lower and the accumulation period started earlier and ended later in CR than in WR. Moreover, the chilling accumulation was broken into two periods by the low deep winter temperature in CR, and that interruption will be removed by future strong winter warming. Future asymmetric warming, with a stronger temperature increase in winter than in spring, could decrease the forcing accumulation effects and increase the chilling effects on the spring phenology of plants in CR. This change in the balance between chilling and forcing will lead to a shift in plant phenology, which will further have major impacts on biogeochemical cycles and on ecosystem functions and services. The consumption of psychoactive substances is considered a growing problem in many communities. Moreover, new psychoactive substances (NPS) designed as (legal) substitutes to traditional illicit drugs are relatively easily available to the public through e-commerce and retail shops, but there is little knowledge regarding the extent and actual use of these substances. This study aims to gain new and complementary information on NPS and traditional illicit drug use at six music festivals across Europe by investigating wastewater and pooled urine. Samples were collected, between 2015 and 2018, at six music festivals across Europe with approximately 465.000 attendees. Wastewater samples were also collected during a period not coinciding with festivals. A wide-scope screening for 197 NPS, six illicit drugs and known metabolites was applied using different chromatography-mass spectrometric strategies. Several illicit drugs and in total 21 different NPS, mainly synthetic cathinones, phenethylamines and tryptamines, were identified in the samples.
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