目前,天津市西青区大气污染防治进入攻坚期.因此,本文对西青区2017—2019年空气质量自动监测数据进行分析.结果表明,西青区空气质量有逐年向好的趋势,但O3污染问题日益突出;PM2.5占比有所下降,但它依旧是最主要的污染物;O3占比超过PM10和NO2,成为仅次于PM2.5的第二大污染物.O3各月浓度呈凸形分布,其他污染物浓度总体呈凹形分布.最值浓度基本分布在7—8月和12至次年1月.O3日变化为明显的单峰结构,其他污染物呈双峰结构.今后大气防治重点应从颗粒物的复合污染转为颗粒物复合污染与臭氧污染协同治理,全年紧抓颗粒物污染防治,同时长期坚持不懈地抓移动源污染治理,并做好道路交通优化.

天津市空气质量保障期间PM2.5浓度为27μg/m3,达到历史同期最好水平;水溶性离子浓度为9.02μg/m3,比保障期前和保障期后分别降低64.70％和39.66％.各离子浓度由高到低为NO3->NH4+>SO2-4>Cl->Na+>K+>NO2->Ca2+>Mg2+>F-,NO3-、NH4+和SO2-4等二次离子是PM2.5中最主要的离子成分.硫氧化率(SOR)和氮氧化率(NOR)分别为0.18和0.14,虽低于保障期前和保障期后,但仍存在明显的二次转化过程.NOR日变化趋势表明夜间及上午时段NO2向NO3-的二次转化较为剧烈.

气溶胶光学厚度是气溶胶最重要的参数之一,是表征大气浑浊程度的关键的物理量,对大气辐射平衡、空气质量等都有重要影响.基于葵花8号卫星气溶胶光学厚度(AOD)产品,分析了天津市2018—2019年气溶胶光学厚度时空分布特征.结果表明,天津气溶胶光学厚度(AOD)均值为0.497,高值区分布在蓟州中东部、宝坻中部、静海团泊洼及塘沽地区.气溶胶光学厚度秋季最高0.672、冬季最低0.337,由高到低依次为秋季>夏季>春季>冬季.月变化曲线表现为双峰结构,最高峰分布在10～11月,次高峰分布在6～7月.

To investigate the characteristics of carbonaceous species in PM2.5 in BTH (Beijing Tianjin and Hebei) area,ambient PM2.5 samples were simultaneously collected in five urban sites (i.e.Beijing,Tianjin,Baoding,Shijiazhuang,Changzhou) from July 2015 to April 2016.The carbonaceous species including organic carbon (OC) and element carbon (EC) were analyzed by a thermal optical carbon analyzer (Model 2001A,DRI,USA).The EC tracer method was used to estimate the concentrations of secondary organic carbon (SOC) in PM2.5.The results showed that the annual average concentrations of OC,EC and SOC were 12.9 ～ 28.5,4.1 ～ 7.9 and 3.3 ～ 10.4 μg.m-3,respectively;and the annual average values of OC/EC and SOC/ OC were up to 2.4～3.0 and 0.26～0.32,respectively.The spatial variations of OC and EC concentrations were the same orders:Baoding ＞ Shijiazhuang ＞ Cangzhou ＞ Tianjin ＞ Beijing,and the seasonal variations of OC and EC concentrations were the also same order:summer ＜ spring ＜ autumn ＜ winter.The OC/EC ratios were lowest in summer and highest in winter at all the sampling sites,likely due to the additional coal-combustion for heating and the adverse meteorological-conditions in winter.The highest correlation of OC and EC was found in winter and lowest in summer,which probably indicated that the sources of OC and EC were higher homology in winter,and the sources of OC were comparatively complicated in summer.The higher SOC concentrations in winter were likely due to the low temperature,the high concentrations of gaseous precursors resulted from coal combustion,and the unfavorable meteorological conditions such as the temperature inversion,the calm wind and the low height of mixed layer.Overall,the pollution characteristics of carbonaceous aerosols showed the spatial consistency in the plain area of BTH.

社会经济水平的不断提升也带动了我国建筑行业的高速发展,在建筑工程建设中,土建施工现场管理作为工程管理的重要内容,应当保持足够的重视度,同时采取合理的管理策略去强化现场管理实效,进而保证土建施工的有序开展.文章将针对目前建筑工程土建施工现场管理中存在的问题进行分析,并提出一系列的优化策略,希望能够为相关从业人员提供参考.

Based on grid air pollution prevention and control work,research of air automatic monitoring in small scale and dense network were developed,and air automatic monitoring system in street-township level of Tianjin was set up This system was used for monitoring particulate concentration in street-township level,the space-time distribution characteristics of particulate concentration were fine analyzed,and high pollution areas of particulate concentration were precise located This system was widely applied for precise location of air pollution,assessment of air quality and analysis of regional transmission of air pollution,and could provide scientific support for air pollution prevention and control,also the reference basis for other provinces to carry out related work.

To study the characteristics and causes of atmospheric heavy pollution episodes in winter of Tianjin,the concentrations of air pollutants,chemical characteristics of particulate matter and the meteorological parameters were analyzed in this study.The major conclusions were obtained as follows.During the heavy pollution episodes,the wind speeds kept below 4.0m/s the relative humidity were larger than 80％,and the mixing heights were only one third to one second of that in the clean days.The NO2/SO2 ratios were lower in heavy pollution days than that in clean days,and the NO3/SO42 ratios were larger than lduring pollution days,indicating that both vehicle exhaust and stationary sources were dominant in Tianjin.Compared to clean days,the PM2.5/PM1o ratios during the heavy pollution episodes were larger while the PM1/PM2.5 ratios were relatively lower,probably because of the hygroscopic behavior of fine particles and the coarse particles from coal combustion.At the beginning of pollution processes,the NOR values were larger than SOR,however,as the development of pollution,the SOR values exceeded NOR due to the limit of ammonia's concentration,indicating that more attention should be focused on gaseous precursors especially sulfur dioxides.OC and EC were weakly correlated when both of them have high concentrations.SOC contributed 20％ to 54％ of OC,indicating that the residential bulk coal burning and secondary organic reactions greatly affected heavy pollution episodes.

本文基于山东省2000—2013年城市化与产业结构的相关数据，计算出山东省城市化与产业结构的灰色关联系数与产业结构演变城市化响应系数，并对计算结果进行了分析。分析结果表明：近15年与城市化水平关联系数最大的是第三产业，其次是第二产业，最后是第一产业；山东省各城市产业结构演变城市化响应系数呈东高西低、北高南低、沿海高内陆低的地理分布特征基于此，本文提出了相应的对策建议。

To better understand the characteristics and sources of chemical composition of atmospheric precipitation in Tianjin,precipitation samples were collected at Tianjin Environmental Monitoring Center,Tanggu Environmental Monitoring Station and Jixian Environmental Monitoring Station from January to December 2013. The values of p H,electrical conductivity( EC) and main ions were analyzed. The volume-weighted means of p H and EC were 5. 58 and 98 μS/cm,respectively. The volume-weighted mean equivalent concentrations of precipitation components showed a decreasing order Ca2 + SO42- NH4+ NO3- Cl- Mg2 + Na+F- K+. Ca2 +, SO42-, NH4+, NO3-and Cl-were the dominant compositions in precipitation,accounting for 91. 3% of the total ions. The ratio of SO42-/NO3-in precipitation was 2. 1in 2013, which represented a decreasing trend over the past decade. This shows that the type of air pollution in Tianjin clearly changed to be complex pollution. Significant seasonal variations in the total ionic equivalent concentrations existed; the totalconcentrations were high in winter and low in summer. SO42-,NH4+and NO3-showed high values in winter,while Ca2 +varied slightly in spring and winter. The chemical compositions of precipitation at the studied sites were influenced by compositive sources,industrial and marine sources,and industrial and agricultural sources. The enrichment factor was used to assess sources of major ions. Ca2 +and K+were determined to be mainly originated from crust sources. Mg2 +was partly from marine sources,though the contribution from soil sources was also considerable. Cl-mainly came from both marine and anthropogenic sources,while SO42-and NO3-were mostly attributable to anthropogenic sources.

Population density,imbalanced index,concentration index, lorenz curve and spatial auto-correlation analysis model were used to study the population distribution characteristic of Tianjin District and its spatial auto-correlation based on GIS soft. The results show that: The total population quantity of each county are almost the same but the difference of their densi-ties is huge,showing very high density in Center City; The concentration index and imbalanced index of Tianjin District is 0.0390 and 0.3893 respectively, indicating that the tendency of concentration is obvious and the population distribution is not balance among counties;Lawrence population curve shows that about 40% of the total population is centered in the land area accounting for less than 2%of the administrative area;The global Moran’s I of Tianjin District is 0.4591,suggesting the popu-lation distribution is not a random process and the distributional pattern has a stronger spatial autocorrelation. Based on popu-lation density,LISA analysis results,combined with the situation in Tianjin city,Tianjin population distribution pattern can be divided into three-concentric-ring structure.

利用天津市环境空气监测数据及相关资料,统计分析其环境空气质量状况.结果表明,2013年天津市环境空气质量达标率为40％,重度及以上污染日有49天,主要发生在冬季,超标日的首要污染物以细颗粒物、可吸入颗粒物和臭氧为主.在空气质量污染物构成中,细颗粒物占比为29.43％,其次为可吸入颗粒物占比22.18％,表明天津市大气污染以颗粒物为主.细颗粒物与可吸入颗粒物的月均浓度线性相关系数为0.918 4,占比为64％.除臭氧以外的五项主要污染物在冬季污染最重,夏季污染较轻,臭氧浓度变化与气温变化保持一致,夏季最高,冬季最低.在市域内,滨海新区、蓟县和西青空气质量较好,红桥、宁河和北辰空气质量较差;气态污染物比颗粒物的空间分布更受局地排放的影响,而颗粒物污染分布具有区域性趋势.

2001-2013年对天津市降水样品进行了采集,分析了pH、电导率(EC)、主要离子浓度(SO42-、NO3-、Cl-、F-、NH4+、Ca2+、Mg2+、Na+、K+).结果表明:2001-2013年,降水的雨量加权平均pH、EC分别为5.48、87 μS· cm-1.降雨的pH、EC及总离子当量浓度呈现上升趋势,酸雨频率呈现下降趋势.降水中各离子雨量加权平均当量浓度排列顺序为:SO2-＞Ca2+ ＞NH4+ ＞NO3-＞Cl-＞Mg2+ ＞Na+ ＞F-＞K+,SO42-、Ca24+、NH4+和NO3-是降水中的主要离子,占离子总量的84.8％.SO42-雨量加权平均当量浓度表现为先轻微上升,后显著下降趋势.NO3-、Ca2+雨量加权平均当量浓度表现为明显上升趋势.NH4+雨量加权平均当量浓度显示为下降趋势.F-、Cl-、K+、Mg2+、Na+等雨量加权平均当量浓度变化趋势基本保持平稳.SO42-对总阴离子的分担率、NH4+总阳离子的分担率均呈现下降趋势.NO3-对总阴离子的分担率、Ca2+对总阳离子的分担率均呈现明显上升趋势.[NO3-]/[SO42-]、[Ca2+]/[NH4+]呈现出明显上升趋势.富集因子计算结果表明:Ca2+主要来自地壳.Mg2+和K+部分来自海源输入,但绝大部分来自地壳.大部分Cl-来自海源的输入,其余小部分来自地壳和人为排放.降水中SO42-、NO3-主要来自人为活动.

2014年11月6-11日,亚太经济合作组织(APEC)会议在北京市召开,京津冀区域采取了最高级别的空气质量保障措施.于2014年11月3-20日同步手动采集天津市PM2.5样品,对APEC会议期间(2014年11月3-11日,在此期间实施了空气质量保障措施)及会议后(2014年11月12-20日)天津市PM2.5中水溶性无机离子组分浓度、二次转化特征等进行了分析.结果表明,APEC会议期间,天津市PM2.5平均质量浓度为78 μg/m3,而会议后达到87 μg/m3;会议期间PM2.5中水溶性无机离子的浓度为NO3-＞SO42-＞NH4+＞Cl-＞K+＞Na+＞Ca2+＞Mg2+,会议后,除Mg2+外,各项离子浓度均有不同程度的上升;会议期间,PM2.5中NO3-浓度最高,在水溶性无机离子中所占比例为38.9％,其次为SO42-(为22.0％)、NH4+(为20.8％),3者所占比例合计为81.7％,会议后3者所占比例降至75.0％;会议期间的大气污染以流动源为主;会议后,硫氧化率和氮氧化率均不同程度减弱,说明会议期间的二次离子转化更为明显;会议期间的停工停产措施对PM2.5中一次离子来源有明显改变,城市扬尘得到明显抑制.