| 1. |
- Shao, Yue, et al.
(författare)
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Scalable Synthesis of Photoluminescent Single-Chain Nanoparticles by Electrostatic-Mediated Intramolecular Crosslinking
- 2022
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 61:27
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Tidskriftsartikel (refereegranskat)abstract
- We report the large-scale synthesis of photoluminescent single-chain nanoparticles (SCNPs) by electrostatic-mediated intramolecular crosslinking in a concentrated solution of 40 mg mL−1 by continuous addition of the free radical initiator. Poly(vinyl benzyl chloride) was charged by quaternization with vinyl-imidazolium for the intramolecular crosslinking by using 2,2-dimethoxy-2-phenylacetophenone (DMAP) as the radical initiator. Under the electrostatic repulsion thus interchain isolation, the intrachain crosslinking experiences the transition from coil through pearl-necklace to globular state. The SCNPs demonstrate strong photoluminescence in the visible range when the non-emissive units are confined thereby. Composition and microstructure of the SCNPs are tunable. The photoluminescent tadpole-like Janus SCNP can be used to selectively illuminate interfacial membranes while stabilizing the emulsions.
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| 2. |
- Wang, Dashan, et al.
(författare)
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The Critical Effect of Subgrid-Scale Scheme on Simulating the Climate Impacts of Deforestation
- 2021
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Ingår i: Journal of Geophysical Research - Atmospheres. - : American Geophysical Union (AGU). - 2169-897X .- 2169-8996. ; 126:17
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Tidskriftsartikel (refereegranskat)abstract
- Land surface schemes (LSSs) in Earth System Models simulate how vegetation regulates land-atmosphere fluxes of heat, water, carbon, and momentum. Despite advances in the spatial resolution of regional climate modeling, significant land cover changes occured at sub-grid scale still not properly treated. Here, we investigate the response of evapotranspiration, representing the fluxes of heat and water, to deforestation in Southeast Asian Massif by employing three LSSs (Noah mosaic, Noah-MP and Community Land Model (CLM)) with different approaches in representing sub-grid variability, implemented in the Weather Research and Forecasting model. Two experiments, with and without satellite-observed deforestation, were performed for each scheme. Results show that the simulations are highly sensitive to the subgrid-scale approaches embedded in the LSSs. Compared with the observed historical climate, CLM outperforms other schemes and Noah mosaic shows the largest bias. However, if we target the simulation of the climate impacts of land cover change, the Noah mosaic scheme taking the sub-grid approach can better capture the response of evapotranspiration to deforestation. The NoahMP and CLM schemes underestimate the evapotranspiration response in the grid cells where the dominant land cover type has not changed, but overestimate the response in those grid cells with dominant type changed, which is a characteristic of dominant-grid approach. To improve our understanding of climate impacts induced by fine-scale land cover change, future efforts to better represent subgrid-scale variability and land-atmosphere flux exchange in climate models are desirable.
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| 3. |
- Yang, Hui, et al.
(författare)
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Multicriteria evaluation of discharge simulation in Dynamic Global Vegetation Models
- 2015
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Ingår i: Journal of Geophysical Research: Atmospheres. - 2169-8996. ; 120:15, s. 7488-7505
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we assessed the performance of discharge simulations by coupling the runoff from seven Dynamic Global Vegetation Models (DGVMs; LPJ, ORCHIDEE, Sheffield-DGVM, TRIFFID, LPJ-GUESS, CLM4CN, and OCN) to one river routing model for 16 large river basins. The results show that the seasonal cycle of river discharge is generally modeled well in the low and middle latitudes but not in the high latitudes, where the peak discharge (due to snow and ice melting) is underestimated. For the annual mean discharge, the DGVMs chained with the routing model show an underestimation. Furthermore, the 30year trend of discharge is also underestimated. For the interannual variability of discharge, a skill score based on overlapping of probability density functions (PDFs) suggests that most models correctly reproduce the observed variability (correlation coefficient higher than 0.5; i.e., models account for 50% of observed interannual variability) except for the Lena, Yenisei, Yukon, and the Congo river basins. In addition, we compared the simulated runoff from different simulations where models were forced with either fixed or varying land use. This suggests that both seasonal and annual mean runoff has been little affected by land use change but that the trend itself of runoff is sensitive to land use change. None of the models when considered individually show significantly better performances than any other and in all basins. This suggests that based on current modeling capability, a regional-weighted average of multimodel ensemble projections might be appropriate to reduce the bias in future projection of global river discharge.
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