Zhang, T.; Chang, J.; Ma, Y.; Sun, Y., and Liu, C., 2020. Study on the evolution characteristics of coastal wetlands of Bohai Sea in Shandong Province under the influence of human activities. In: Hu, C. and Cai, M. (eds.), Geo-informatics and Oceanography. Journal of Coastal Research, Special Issue No. 105, pp. 28–32. Coconut Creek (Florida), ISSN 0749-0208.Using the coastal area of Bohai Sea in Shandong Province as the study area, the evolution law of coastal wetlands under the influence of human activities is discussed in this paper. The results are as follows. (1) The wetland area in the study area increased from 1990 to 2019, mainly because of the transformation from forest-grassland to a constructed wetland. The area of constructed wetlands increased significantly, whereas the area of natural wetlands decreased significantly. (2) The overall evolution rate of land use was on the rise, with the average value rising from 21.58 in 1990–2000 to 32.01 in 2010–19. The evolution rate from natural wetland to constructed wetland in the western region was generally faster than the rate in the eastern region. (3) The intensity of human activities in the region was different, and the dominant role of wetlands is inversely proportional to the intensity. The areas with higher intensity of human activities increased, whereas the areas with lower intensity of human activities decreased. (4) During the study period, with the increasing of the area of salt fields and the transformation of natural wetlands to other types of land use, the area of wetlands in higher intensity areas was small and increased, whereas in lower intensity areas it was reduced.
Abstract The artificial photosynthesis of hydrogen peroxide (H 2 O 2 ) using semiconductor photocatalysts is gaining attention as an eco‐friendly and energy‐efficient method. Covalent organic frameworks (COFs) show great promise in enhancing photocatalytic H 2 O 2 production due to their tunable structures and functional diversity. However, the efficiency of H 2 O 2 generation is close to the photoelectric properties of COFs and the microenvironment of their active sites. Herein, the synthesis of pyridyl‐imine‐functionalized COFs (PyIm‐COFs) featuring donor–acceptor (D–A) moieties to improve H 2 O 2 production efficiency is reported. By employing benzothiadiazole (BT) units with varied fluorine substitutions, the electronic environment of the active sites, optimizing the selective two‐electron (2e − ) oxygen reduction reaction (ORR), is tuned. Among the synthesized COFs, PyIm‐BT_F exhibits the highest photocatalytic activity, achieving a H 2 O 2 production rate of 5342 µmol g −1 h −1 . The importance of D–A moieties in the rational design of COF‐based photocatalysts, providing a novel strategy for sustainable H 2 O 2 production through optimized active site environments, is underscored.
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