In this work, Er3+:YAlO3/ZnO–TiO2 and ZnO–TiO2 composites were prepared by the ultrasonic dispersion and liquid boiling method. In succession, they were then characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Acid red B as a model dye compound was degraded under solar light irradiation to evaluate the photocatalytic activities of the Er3+:YAlO3/ZnO–TiO2 and ZnO–TiO2 composites. We found that the photocatalytic activity of ZnO–TiO2 composite can be enhanced by adding an appropriate amount of Er3+:YAlO3. We reviewed influencing factors, such as Er3+:YAlO3 content, heat-treated temperature and heat-treated time on the photocatalytic activity of the Er3+:YAlO3/ZnO–TiO2 composites. In addition, the effects of solar light irradiation time, dye initial concentration, Er3+:YAlO3/ZnO–TiO2 amount and solution acidity on the photocatalytic degradation of acid red B dye in aqueous solution were investigated in detail. Simultaneously, the degradation and comparison of other dyes such as methyl orange (MO), rhodamine B (RM-B), azo fuchsine (AF), congo red (CG-R) and methyl blue (MB) were also reviewed. In addition, we attempted to explore both the principle of possible excitation of Er3+:YAlO3/ZnO–TiO2 under solar light irradiation and the mechanism of photocatalytic degradation. 相似文献
Abstract Ground level ozone pollution has become a significant air pollution problem in Beijing. Because of the complex way in which ozone is formed, it is difficult for policy makers to identify optimal control options on a cost-effective basis. This paper identifies and assesses a range of options for addressing this problem. We apply the Ambient Least Cost Model and compare the economic costs of control options, then recommend the most effective sequence to realize pollution control at the lowest cost. The study finds that installing of Stage II gasoline vapor recovery system at Beijing’s 1446 gasoline stations would be the most cost-effective option. Overall, options to reduce ozone pollution by cutting vehicular emissions are much more cost-effective than options to “clean up” coal-fired power plants. 相似文献
Abstract As the protected areas of land and coastal environment, nature reserves are designed to address how to reconcile the conservation of biodiversity, the quest for economic and social development and the maintenance of cultural values. This paper establishes a framework for nature reserve development that seeks to incorporate ecotourism into its strategies. The overall purpose was to identify the information needs required for a comprehensive nature reserve that incorporates ecotourism related values. It also illustrates the utility of this framework in the context of the Wuzhishan Mountain Region of China. A literature review, the first phase of a visionary strategy and a subsequent gap analysis for available management information were undertaken in order to achieve this paper's purpose. Finally, recommendations are presented for integrating ecotourism into nature reserve development in the Wuzhishan Mountain Region. 相似文献
We assessed the vulnerability of 208 endemic or endangered species in China to the effects of climate change, as a part of the project “Research on China’s National Biodiversity and Climate Change Strategy and Action Plans”. Based on the China Species Information System, we selected comprehensive species as analysis targets, covering taxa including mammals, birds, reptiles, amphibians and plants. We applied nine species distribution models in BIOMOD (a package of R software) to estimate the current (1991–2010) ranges and predicted future (2081–2100) ranges of these species, using six climate variables based on Regional Climate Model version 3 (RegCM3) and A1B emission scenario. The model results showed that different taxa might show diverse potential range shifts over time. The range sizes of half of the species (104 species) would decrease, and those of another half would increase. We predicted that the future remaining ranges (intersection of current and future ranges/current ranges) of 135 species would be less than 50 % of their current range sizes. Species that are both endemic and critically endangered would lose more of their range than others. In summary, the most vulnerable species are currently found on the Qinghai-Tibetan Plateau, in the Hengduan Mountain Range, and southern China. Future action plans dealing with climate change in China should be prepared with consideration for vulnerable species and their habitats. 相似文献
Environmental Geochemistry and Health - The arsenic-contaminated groundwater has attracted attention in much south and southeast Asian deltas, however, mainly on the deep aquifers. Here, arsenic... 相似文献
The problem of algal bloom caused by eutrophication has attracted global attention. Many scholars have studied the problem associated with algae bloom, but few have carried out dynamic monitoring, instead focusing on the formation mechanism of cyanobacteria. For our study of the Taihu Lake in China, we used Moderate-Resolution Imaging Spectroradiometer (MODIS) and Landsat remote sensing image data from 2017 to establish a prediction model. First, we used MODIS data to retrieve the concentration of N, P, and chlorophyll a in water. Then, we applied the analytic hierarchy process (AHP) model to the inversion results to construct the diffusion potential index. Finally, we used C# to compile the cellular automata (CA) model. We found that the distribution of cyanobacteria predicted by our method was consistent with the algal bloom situation of Taihu Lake in 2017. The results showed that the method effectively predicts the dynamic transfer of cyanobacteria from outbreak to diffusion in a short period of time, which can help decision-makers monitor lake health.