In this paper, atmospheric environmental background, weather conditions and formation mechanism of one typical air pollution episode in Beijing during October 6th -12th, 2014 were investigated by combining observed da...In this paper, atmospheric environmental background, weather conditions and formation mechanism of one typical air pollution episode in Beijing during October 6th -12th, 2014 were investigated by combining observed data with numerical model CAMx. Results showed that the occurrence of heavy air pollution resulted mainly from stable atmospheric conditions regionally or locally. Observed heavy pollution episodes were characterized by a stagnant atmospheric structure with average wind speed of 1.56 m/s, high humidity of 83.13%, large inversion strength of 3.42℃（3/100 m which were disadvantageous to the dispersal of air pollutants. The air pollution episode during October 8th -11th was the most serious with daily average PM2.5 concentration of 264 μg/ms in Beijing, and heavily polluted land area at Beijing, Tianjin and Hebei districts was about 2 × 10^5 km2. Model research showed that regional transmission contributions to the receptor sites in Beijing were between 61% -69% dudng 8th -11th, and regional transportation played a more important role in this serious air pollution episode. Key words Serious pollution incident; Formation mechanism; Regional transportation; Inversion layer; Beijing; PM2.5展开更多
文摘目的: 观察三种不同药物(坦索罗辛、硝苯地平、消旋山莨菪碱)治疗输尿管下段结石的临床疗效。 方法: 采用简单随机分组方法,选取我院2016年1月至2018年12月我院90例输尿管下段结石患者,分为坦索罗辛组、硝苯地平组、消旋山莨菪碱组及对照组,分别为22例、23例、22例、23例。四组患者均需要大量饮水保证每日总尿量>2000mL,其中坦索罗辛组、硝苯地平组、消旋山莨菪碱组给药方式为0.4mg po qd、10 mg po tid、10mg po tid,对照组则不给予药物干预,疗程为2周。观察各组患者治疗效果,比较排石直径、排石时间和残留结石直径,记录不良反应的发生情况。 结果: 总有效率:坦索罗辛组>消旋山莨菪碱组>硝苯地平组>对照组(P<0.05);排石大小:坦索罗辛组>消旋山莨菪碱组>硝苯地平组>对照组(P<0.05);排石时间:坦索罗辛组<硝苯地平组<消旋山莨菪碱组<对照组(P<0.05),硝苯地平组、消旋山莨菪碱组比较提示差异无统计学意义(P>0.05);残留结石大小:坦索罗辛组<硝苯地平组<消旋山莨菪碱组<对照组(P<0.05);治疗期间四组患者未出现明显不良反应。 结论: 坦索罗辛治疗输尿管下段结石患者方面较硝苯地平、消旋山莨菪碱具有更佳的临床疗效,硝苯地平与消旋山莨菪治疗效果相似,三组安全性较好。
文摘In this paper, atmospheric environmental background, weather conditions and formation mechanism of one typical air pollution episode in Beijing during October 6th -12th, 2014 were investigated by combining observed data with numerical model CAMx. Results showed that the occurrence of heavy air pollution resulted mainly from stable atmospheric conditions regionally or locally. Observed heavy pollution episodes were characterized by a stagnant atmospheric structure with average wind speed of 1.56 m/s, high humidity of 83.13%, large inversion strength of 3.42℃（3/100 m which were disadvantageous to the dispersal of air pollutants. The air pollution episode during October 8th -11th was the most serious with daily average PM2.5 concentration of 264 μg/ms in Beijing, and heavily polluted land area at Beijing, Tianjin and Hebei districts was about 2 × 10^5 km2. Model research showed that regional transmission contributions to the receptor sites in Beijing were between 61% -69% dudng 8th -11th, and regional transportation played a more important role in this serious air pollution episode. Key words Serious pollution incident; Formation mechanism; Regional transportation; Inversion layer; Beijing; PM2.5
