基于模糊理论的城市交通生态环境综合评价模型研究

根据城市交通生态环境系统的复杂性,对影响城市交通生态环境质量的指标因素进行提炼,确定了指标因素的隶属度函数,建立了基于不同模糊算子的城市交通生态环境质量多阶模糊综合评价模型.针对合肥市4条道路的交通环境质量监测数据,利用建立的评价模型,采用不同的模糊算子进行分析优化.此模型也可用于其他城市交通生态环境质量的评价.     

Concentrations,sources, and influential factors of water- soluble ions of atmospheric particles in Dunhuang Mogao Grottoes,a world heritage site in China

Atmospheric particle pollution is one of the major factors leading to degradation of ancient wall paintings, particularly heritage sites in arid and semi-arid regions. However, current systematic research on the changes, sources, and influential factors of atmospheric particulate matter and its water-soluble ion concentrations is not sufficient. Thus, the major water-soluble ion concentrations, sources, and influential factors of atmospheric particles PM_2.5 and PM₁₀ (particulate matter with an aerodynamic equivalent diameter ≤2.5 and 10.0 μm, respectively, in ambient air) were collected from Cave 16 and its ambient exterior environment in the Dunhuang Mogao Grottoes, China, between April 2015 and March 2016. Results showed that the concentrations of PM_2.5 and PM₁₀ inside and outside the cave were the highest in March 2016 and the lowest in December 2015. The higher particle concentration from March to May was related to the frequent occurrence of sand and dust events, and the lower particle concentration from June to September was associated with good diffusion conditions, increased precipitation, and an established cave shelterbelt. The concentration of particulate matter inside the cave was affected by the concentration of particles in the air outside the cave. Ca²⁺, NH+ 4, Na⁺, Cl^-, and SO2- 4were the main components of the total ions of PM_2.5 and PM₁₀ both inside and outside the cave. The total ions inside the cave were frequently affected by the disturbance of tourists' activities during the peak tourist season from May to August. Under the influence of dust, the total concentrations of Cl^-, SO2- 4, Na⁺, NH+ 4, and Ca²⁺ in particles of different sizes inside and outside the cave increased, and the concentrations of Cl^-, SO2- 4, Na⁺, and Ca²⁺ decreased during precipitation period. Backward air mass trajectory analysis suggested that the pollutants were mainly from Xinjiang, China. The pollutant sources of air particulates are straw burning, secondary pollution sources, soil dust, dry spring rivers, and tourist activities.