2012~2013年间北京市PM2.5中水溶性离子时空分布规律及相关性分析

2012年8月~2013年7月,在北京市包括城市背景、城区、郊区以及边界传输点在内的9个监测点位进行大气细颗粒物PM2.5样品的采集与分析,共获得486个有效样本及9种水溶性离子的质量浓度.观测期间9种水溶性离子总质量浓度为60.5μg·m-3,浓度水平高低顺序分别为NO-3SO2-4NH+-4Cl-Na+K+Ca2+F-Mg2+;其中SO2-4、NO-3和NH+4(三者简称SNA)占全部所测水溶性离子的88%;NO-3是全年波动范围最大的二次离子.对所测阴、阳离子相关性研究发现,阴、阳离子总体相关性良好,春、冬季阴、阳离子相关性要好于夏、秋季.对不同颗粒质量级别中的水溶性离子研究发现,SNA积累活跃,相对于SO2-4的积累,NO-3和NH+4在二次离子的形成过程中占据主导地位;NO-3是重污染过程累积效应比较明显且贡献相对较高的二次离子.     

山东省不同地形区降雨侵蚀力时空变化特征

掌握降水及降雨侵蚀力的时空分布和演变特征对于揭示区域气候变化规律,有效预防和科学评估水土流失等环境问题具有重要意义。基于34个气象站点1961—2015年的降水日值数据,采用降雨侵蚀力计算模型、Mann-Kendall检验、小波分析和Kriging空间插值等研究方法,分析研究了山东省内山地、丘陵和平原等不同地形区的降水和降雨侵蚀力时空变化特征。结果显示：近55年间,全省及各地形区的降水量和降雨侵蚀力均呈波动下降趋势,年内分配均集中在夏季,降雨侵蚀力在时间尺度上存在25年左右的变化周期。空间上,降水和降雨侵蚀力均呈现鲁中南山区＞胶东半岛丘陵区＞鲁西北平原区;分界线由东北至西南沿福山—莱阳—淄博—定陶等站呈“S”型贯穿山东省,界线东南侧降雨侵蚀力高,西北侧降雨侵蚀力较低。其原因主要是受海拔和地形的影响,东南季风携带湿润气流受胶东半岛丘陵及鲁中南山地的阻挡抬升,致使“S”型分界线东南侧迎风面降水及降雨强度相对较高;西北侧背风面形成焚风效应,降水及降雨侵蚀强度较低。该结果可为山东省水土流失空间特征分析奠定数据基础,同时为区域水土资源利用与调控及生态环境保护与改善提供决策支撑。     

Geographic Variation in the Seasonal Reproductive Strategy of the Mite Varroa jacobsoni in the Honeybee Nest

Variation in the reproduction of Varroa jacobsoni mite was studied in relation to the expansion of the range of its parasitism on the honeybee. Geographic differences in the seasonal dynamics of mite reproduction in the nests of bee families were revealed. Variation in the sex ratio of mites and the factors inhibiting their reproduction at the northern boundary of the honeybee range are considered. The forms of parthenogenetic reproduction in V. jacobsoni are discussed.     

Comparison of temporal and Spatial Characteristics of Ozone Pollution at Ground Level in the Eastern China

Monitoring data from ozone（O3） automatic stations in three typical cities with different climatic areas in the southern and northern parts of eastern China are used to analyze temporal and spatial characteristics of ozone pollution at ground level. The results show that ozone pollution level has distinct regional differences and the concentration in the suburbs is higher than that in the urban areas. The seasonal variation of ozone concentration in different climatic areas is greatly affected by the variation of precipitation. Ozone concentration in Shenyang and Beijing , in the temperate zone, has one perennial peak concentration, occurring in early summer, May or June. Ozone concentration in Guangzhou, in sub-tropical zone, has two peak values year round. The highest values occur in October and the secondary high value in June. The ozone season in the south is longer than that in the north. The annual average daily peak value of ozone concentrations in different climates usually occur around 3 pm. The diurnal variation range of ozone concentration declines with the increase of latitude. Ozone concentration does not elevate with the increase of traffic flow. Ozone concentration in Guangzhou has a distinct reverse relation to CO and NOx. This complicated non-linearity indicates that the equilibrium of ozone photochemical reaction has regional differences. Exceeding the rate of Beijing＇s lh ozone concentration is higher than that of Guangzhou, whereas the average 8h ozone level is lower than that of Guangzhou, indicating that areas in low latitude are more easily affected by moderate ozone concentrations and longer exposure. Thus, China should work out standards for 8h ozone concentration.     

A case study of spatial variation and enrichment of selected elements in ambient particulate matter around a large coal-fired power station in Central India

The dominant use of coal in power sectors has been associated with adverse environmental impacts. Ambient air monitoring for the two size fractions of particulate matter, respirable suspended particulate matter (RSPM) and non-respirable suspended particulate matter (NRSPM) in the downwind and upwind directions of a large coal-fired power station in central India, was carried out. Collected samples of ambient particulate matter were analysed atomic absorption spectrophotometrically for 15 elements. Spatial variability in elemental composition of RSPM and NRSPM and the degree of enrichment of these toxic metals in RSPM were investigated. A significant spatial variability for the elements in RSPM and NRSPM and higher degrees of enrichment of the elements were observed.     

Variation in certain characters and properties of scotch pine needles in geographic cultures

Morphophysiological and anatomical characters of needles that are used for characterizing infraspecific taxa have been studied in Scotch pine geographic cultures established in the forest-steppe zone of Siberia. Variation in these characters has been revealed, which reflects the polymorphic structure of the species and the effect of natural selection on the composition of populations in new natural-cimatic conditions.     

丹江口水库水质要素变化特征及其相互关系

采用丹江口水库 1987～ 1996年间的水环境常规监测资料 ,应用因子分析方法探讨了丹江口水库不同区域水环境要素变化特征及其相互关系 ,分析表明 :丹江口水库目前水质良好 ,大多数情况下能满足地面水一类水质标准要求 :库区不同断面水体水质要素及污染因子间的相互关系可以用 6个主导因子表达。同一主导因子不同断面标识因子的差异反映了库区不同区域水质分布差异及产生这种差异的环境过程 ;影响库区水质的主要因素是上游随降水产生的面源污染、库周点源排放、水体自净以及气候因素 ,不同断面水质影响因素及其程度存在差异。     

Seasonal variations of Rn concentrations in the air of a tunnel located in Nagano city

The seasonal variation of 222Rn concentrations in the air of tunnels constructed during World War II at Nagano City has been investigated. The determination of 222Rn concentrations in tunnel air was performed using a solid-state nuclear track detector technique. The monthly radon concentrations changed smoothly, decreasing towards winter and increasing towards summer, and it was found that the concentrations strongly correlate with the temperature difference between the inside and the outside of the tunnel. In the innermost areas of the tunnel, the maximum concentration was observed in July, its value being about 6500 Bq m (-3). The concentrations of radon in the tunnel air decrease exponentially towards the openings of the tunnel, which indicates that the radon concentration in the tunnel is basically governed by diffusion and mixing of radon gas with air. These observations lead to the conclusion that the seasonal variation of the radon concentration in the tunnel air is mainly caused by a convection current due to a stack effect induced by the temperature difference between the tunnel air and the outside air.     

Contribution of anthropogenic pollutants to the increase of tropospheric ozone levels in the Oporto Metropolitan Area, Portugal since the 19th century

The main purpose of this study was to evaluate the contribution of anthropogenic pollutants to the increase of tropospheric ozone levels in the Oporto Metropolitan Area (Portugal) since the 19th century. The study was based on pre-industrial and recent data series, the results being analyzed according to the atmospheric chemistry. The treatment of ozone and meteorological data was performed by classical statistics and by time-series analysis. It was concluded that in the 19th century the ozone present in the troposphere was not of photochemical origin, being possible to consider the respective concentrations as reference values. For recent data a cycle of 8h for ozone concentrations could be related to traffic. Compared to the 19th century, the current concentrations were 147% higher (252% higher in May) due to the increased photochemical production associated with the increased anthropogenic emissions.