目的分析中国（未包括中国香港特别行政区、澳门特别行政区和台湾）2015-2016年疑似预防接种异常反应（Adverse events following immunization,AEFI）的报告发生时间分布特征。方法收集通过中国免疫规划信息管理系统报告的2015-2016年...目的分析中国（未包括中国香港特别行政区、澳门特别行政区和台湾）2015-2016年疑似预防接种异常反应（Adverse events following immunization,AEFI）的报告发生时间分布特征。方法收集通过中国免疫规划信息管理系统报告的2015-2016年接种疫苗数据和全国AEFI监测数据,采用集中度法和圆形分布法分析各类AEFI及重点AEFI发生的时间趋势。结果 2015-2016年共报告AEFI 339 806例,第1、2、3、4季度分别占18.49%、29.82%、28.89%、22.80%;月报告发生率范围为226.52/100万剂（1月）-509.25/100万剂（6月）;全部AEFI的集中度法M值为0.36,报告高峰期为3月9日-10月23日,高峰日为6月25日。在一般反应中,发热（〉38.5℃）和局部反应的M值分别为0.35和0.41,高峰期分别为3月1日-10月24日和3月21日-10月6日,高峰日分别为6月27日和6月28日。在异常反应中,过敏性皮疹、血管性水肿、卡介苗淋巴结炎和过敏性紫癜的M值分别为0.34、0.30、0.25和0.23,高峰日分别为6月19日、6月21日、4月23日和1月4日;血小板减少性紫癜、热性惊厥和过敏性休克的报告发生无明显的时间规律。在偶合症中,上呼吸道感染的M值为0.30,高峰日为6月8日。结论中国AEFI总体报告发生趋势具有季节性,报告高峰可能与AEFI临床疾病种类或疾病本身的季节性等因素有关。展开更多
This study deals with temporal trends in the Penman-Monteith reference evapotranspiration estimated from standard meteorological observations, observed pan evaporation, and four related meteorological variables during...This study deals with temporal trends in the Penman-Monteith reference evapotranspiration estimated from standard meteorological observations, observed pan evaporation, and four related meteorological variables during 1970-2000 in the Yangtze River catchment. Relative contributions of the four meteorological variables to changes in the reference evapotranspiration are quantified. The results show that both the reference evapotranspiration and the pan evaporation have significant decreasing trends in the upper, the middle as well as in the whole Changjiang （Yangtze） River catchment at the 5% significance level, while the air temperature shows a significant increasing trend. The decreasing trend detected in the reference evapotranspiration can be attributed to the significant decreasing trends in the net radiation and the wind speed.展开更多
Long-term trends in vegetation phenology indicate ecosystem change due to the combined impacts of human activities and climate. In this study we used 1982 to 2006 Advanced Very High Resolution Radiometer Normalized Di...Long-term trends in vegetation phenology indicate ecosystem change due to the combined impacts of human activities and climate. In this study we used 1982 to 2006 Advanced Very High Resolution Radiometer Normalized Difference Vegetation Index （AVHRR NDVI） imagery across China and the TIMESAT program to quantify annual vegetation production and its changing trend. Results showed great spatial variability in vegetation growth and its temporal trend across the country during the 25-year study period. Significant decreases in vegetation production were detected in the grasslands of Inner Mongolia, and in industrializing regions in southern China, including the Pearl River Delta, the Yangtze River Delta, and areas along the Yangtze River. Significant increases in vegetation production were found in Xinjiang, Central China, and North-east China. Validation of the NDVI trends and vegetated area changes were conducted using Landsat imagery and the results were consistent with the analysis from AVHRR data. We also found that although the causes of the vegetation change vary locally, the spatial pattern of the vegetation change and the areas of greatest impact from national policies launched in the 1970s, such as the opening of economic zones and the ＇Three-North Shelter Forest Programme＇, are similar, which indicates an impact of national policies on ecosystem change and that such impacts can be detected using the method described in this paper.展开更多
文摘This study deals with temporal trends in the Penman-Monteith reference evapotranspiration estimated from standard meteorological observations, observed pan evaporation, and four related meteorological variables during 1970-2000 in the Yangtze River catchment. Relative contributions of the four meteorological variables to changes in the reference evapotranspiration are quantified. The results show that both the reference evapotranspiration and the pan evaporation have significant decreasing trends in the upper, the middle as well as in the whole Changjiang （Yangtze） River catchment at the 5% significance level, while the air temperature shows a significant increasing trend. The decreasing trend detected in the reference evapotranspiration can be attributed to the significant decreasing trends in the net radiation and the wind speed.
文摘Long-term trends in vegetation phenology indicate ecosystem change due to the combined impacts of human activities and climate. In this study we used 1982 to 2006 Advanced Very High Resolution Radiometer Normalized Difference Vegetation Index （AVHRR NDVI） imagery across China and the TIMESAT program to quantify annual vegetation production and its changing trend. Results showed great spatial variability in vegetation growth and its temporal trend across the country during the 25-year study period. Significant decreases in vegetation production were detected in the grasslands of Inner Mongolia, and in industrializing regions in southern China, including the Pearl River Delta, the Yangtze River Delta, and areas along the Yangtze River. Significant increases in vegetation production were found in Xinjiang, Central China, and North-east China. Validation of the NDVI trends and vegetated area changes were conducted using Landsat imagery and the results were consistent with the analysis from AVHRR data. We also found that although the causes of the vegetation change vary locally, the spatial pattern of the vegetation change and the areas of greatest impact from national policies launched in the 1970s, such as the opening of economic zones and the ＇Three-North Shelter Forest Programme＇, are similar, which indicates an impact of national policies on ecosystem change and that such impacts can be detected using the method described in this paper.
