冬季北京城区大气重污染特征分析

为研究北京市城区大气重污染特征,对2013年12月~2014年2月期间北京市6次大气重污染过程的PM2.5浓度水平、化学组成以及大气氧化性和气象要素特征进行了分析。结果表明,重污染日PM2.5平均质量浓度达到265.0μg/m3,是非重污染日的3.5倍。 PM2.5组分中NO3-,SO42-,NH4+和有机碳(OC)在重污染日的平均浓度分别是非重污染日的6.8,3.4,2.7和2.6倍。前3次过程中SO42-浓度最高,后3次过程中SO42-浓度与NO3-浓度接近。从气象要素来看,重污染期间的基本特征为地面温度升高、相对湿度增大、地面气压降低和风速减小。重污染日的能见度显著降低,平均能见度仅为非重污染日的34.4%。重污染日的大气氧化性明显增强,大气氧化剂OX平均浓度是非重污染日的1.5倍,(OC)/(EC)平均比值是非重污染日的1.6倍。     

安徽及周边地区断层水准变化特征研究

对安徽及周边地区断层水准观测资料分析认为,郯庐断裂带南段安徽和江苏境内的断层以继承性构造运动为主,伴有幅度较大的波动变化;中段山东境内的断层活动主要反映了季节性变化和构造活动。整体上看,研究区内断层活动速率不高,断层均处于正常活动状态。个别断层垂直形变变化趋势与地球自转有一定的相关性,与区域主压应力轴方位角变化比较一致,这种相关表明其垂直形变变化与区域应力变化有关。     

上海市冬季PM_(2.5)无机元素污染特征及来源分析

为了解高污染季节上海市细颗粒物PM2.5及其无机元素的污染特征和来源,于2013年1月4日至2月1日在上海3个点位采集PM2.5样品,并采用电感耦合等离子光谱仪(ICP-OES)测定样品中19种元素含量.结果表明,采样期间PM2.5污染水平较高,均值达(90.5±41.2)μg·m-3,且郊区明显高于市区和背景参照点.所测无机元素的空间分布规律与PM2.5一致,但背景参照点元素Zn的浓度较高.采样期间Cd、As、Zn、Pb、S和Cu等人为污染元素的富集因子较高.因子分析结果表明冬季上海市PM2.5具有多源性,主要来源于燃煤、自然尘、燃油以及机动车.     

北京道路交通环境亚微米颗粒物元素组成特征及来源分析

于2011年12月和2012年8月对北京北四环道路交通环境中亚微米颗粒物(PM1)进行了采样,并对PM1的质量浓度、元素组成及主要来源进行了分析.夏季非灰霾时段PM1日平均浓度为(52.5±29.9)μg·m-3,灰霾时段PM1浓度增加到(154.2±36.3)μg·m-3;冬季非灰霾时段PM1日均浓度为(59.6±32.5)μg·m-3.采用X射线荧光光谱法(XRF)对颗粒物中元素进行分析,共得到Na、Mg、Al、Si、P、S、Cl、K、Ca、Ti、V、Cr、Mn、Fe、Ni、Cu、Zn、As、Cd、Ba和Pb等21种元素的质量浓度.其中S、Cl、K、Na、Si、Zn、Fe和Ca等8种元素含量较高,占测试元素质量浓度90%以上.污染元素浓度呈现显著的季节差异,夏季S元素浓度较高,冬季As、Cl、K、Pb、Mn、V、Cd和P等元素浓度较高.应用富集因子法发现,PM1相对PM2.5能够更好地反映人为源的元素污染特征.应用因子分析法分析出PM1的3个元素浓度贡献主成分因子:因子1反映燃煤、交通源排放和生物质燃烧,因子2反映道路及建筑扬尘贡献,因子3反映机动车排放和工业排放.因子1和因子3之和的夏季和冬季贡献比例分别高达46.8%和68.3%,表明来自机动车、燃煤、生物质燃烧等重要人为源对道路交通环境PM1浓度的贡献显著高于其他来源.灰霾期间S、As、Pb等污染元素浓度明显高于非灰霾期间,地壳元素在灰霾期间无明显浓度变化.     

一种改进的灾害新闻3要素提取方法研究*

为提取灾害性新闻中的基本要素,迅速掌握灾害事件信息和发展趋势,将目标分类和命名实体识别（named entity recognition,NER）相结合,提出改进的灾害新闻3要素提取方法。构建滑动窗检测器搭载不同的分类模型,实现对新闻文本的灾害主题识别与时空位置要素范围判定,结合命名实体识别完成对时空位置要素的精准提取,并以灾害事故信息文本为例进行测试。研究结果表明:通过在火灾、地震和滑坡新闻中进行数据集中测试,发现本文方法相较于LSTM,BILSTM,BILSTM-CRF提取效果更优;本文方法可对大量灾害性新闻的灾害3要素进行识别提取,对灾害信息进行时空规律分析,研究结果可在灾害应急响应中发挥重要作用。     

Chemical compositions of PM2.5 aerosol during haze periods in the mountainous city of Yong'an, China

Haze phenomena were found to have an increasing tendency in recent years in Yong'an, a mountainous industrial city located in the center part of Fujian Province, China. Atmospheric fine particles (PM_2.5) in the urban area during haze periods in three seasons (spring, autumn and winter) from 2007 to 2008 were collected, and the mass concentrations and chemical compositions (seventeen elements, water soluble inorganic ions (WSIIs) and carbonaceous species) of PM_2.5 were determined. PM_2.5 mass concentrations did not show a distinct difference among the three seasons. The carbonaceous species organic carbon (OC) and elemental carbon (EC) constituted up to 19.2%-30.4% of the PM_2.5 mass during sampling periods, while WSIIs made up 25.3%-52.5% of the PM_2.5 mass. The major ions in PM_2.5 were SO₄^2-, NO₃^- and NH₄⁺, while the major elements were Si, K, Pb, Zn, Ca and Al. The experimental results (from data based on three haze periods with a 10-day sampling length for each period) showed that the crustal element species was the most abundant component of PM_2.5 in spring, and the secondary ions species (SO₄^2-, NO₃^-, NH₄⁺, etc.) was the most abundant component in PM_2.5 in autumn and winter. This indicated that dust was the primary pollution source for PM_2.5 in spring and combustion and traffic emissions could be the main pollution sources for PM_2.5 in autumn and winter. Generally, coal combustion and traffic emissions were considered to be the most prominent pollution sources for this city on haze days.     

城区飞散致敏花粉与大气细/超细颗粒物的协同生物效应研究

城市大气颗粒物污染和致敏花粉的污染已经对人群健康和城市空气质量产生了较为严重的影响.这2种污染物的协同生物效应正在成为大气环境科学、环境毒理学、免疫学等学科研究的前沿和热点研究领域.以上海大气中的细/超细颗粒物和日本关东地区致敏花粉(柳杉)为例,阐述了大气细/超细颗粒物的表征以及花粉致敏的过程.在研究中,观察到了日本柳杉花粉壁附着有直径0.7μm的含变应原蛋白的微粒(Ubisch body),并用ELISA法揭示了日本关东地区大气颗粒物中含变应原蛋白的颗粒主要分布在1μm的粒径范围内;而在上海大气颗粒物中,化学元素总量的最大值出现在细/超细粒径颗粒物(0.3～0.18μm)范围,污染元素S和Pb的质量浓度在超细(纳米尺度)/细颗粒物中比在其他粒径范围颗粒物中要高,另外还发现在上海大气颗粒物中有植物花粉的存在.城市大气颗粒物中的主要组分,柴油机车尾气颗粒物(DEPs)与飞散花粉之间存在协同生物效应,但其机制和过程还不清楚,在最新研究成果的基础上并结合国内外相关研究领域的进展,对飞散花粉与大气细/超细颗粒物的协同生物效应的研究进行了总结并提出今后研究的方向.     

江西铜矿及冶炼厂周边土壤和农作物稀土元素含量与评价

研究江西省铜矿开采和冶炼对周边农田土壤、农作物稀土元素含量的影响.结果表明,铜矿开采和冶炼可提高土壤及农作物稀土元素的含量.德兴银山铅锌铜矿和贵溪冶炼厂周边农田土壤中总稀土元素含量范围分别为112.42~397.02mg·kg-1和48.81~250.06 mg·kg-1,总稀土元素平均值分别为254.84 mg·kg-1和144.21 mg·kg-1,分别是江西省背景值的1.21倍和0.68倍,全国背景值的1.36倍和0.77倍,对照样点的3.59倍和2.03倍.贵溪冶炼厂周边10种农作物样品中总稀土元素含量范围为0.35~2.87 mg·kg-1,作物叶子中的稀土元素含量高于茎和块根.番茄、空心菜叶和萝卜叶中总稀土元素含量分别为2.87、1.58和0.80 mg·kg-1,均超过我国蔬菜和水果卫生标准的总稀土元素含量限值(0.70 mg·kg-1).矿区居民终身摄入稀土元素的总量为17.72μg·(kg·d)-1,低于安全剂量和临界值,对人体还不构成健康风险.研究结果说明在江西进行铜矿开采和冶炼时必须重视稀土元素对周边环境的影响.     

Rare earth elements in fly ashes created during the coal burning process in certain coal-fired power plants operating in Poland - Upper Silesian Industrial Region

The subject of the study covered volatile ashes created during hard coal burning process in ash furnaces, in power plants operating in the Upper Silesian Industrial Region, Southern Poland. Coal-fired power plants are furnished with dust extracting devices, electro precipitators, with 99-99.6% combustion gas extracting efficiency. Activity concentrations ofTh-232, Ra-226, K-40, Ac-228, U-235 and U-238 were measured with gamma-ray spectrometer. Concentrations of selected rare soil elements (La, Ce, Nd, Sm, Y, Gd, Th, U) were analysed by means of instrumental neutron activation analysis (INAA). Mineral phases of individual ash particles were identified with the use of scanning electron microscope equipped with EDS attachment. Laser granulometric analyses were executed with the use of Analyssette analyser. The activity of the investigated fly-ash samples is several times higher than that of the bituminous coal samples; in the coal, the activities are: 226Ra - 85.4 Bq kg⁻¹, 40 K-689 Bq kg⁻¹, 232Th - 100.8 Bq kg⁻¹, 235U-13.5 Bq kg⁻¹, 238U-50 Bq kg⁻¹ and 228Ac - 82.4 Bq kg⁻¹.     

Trace elements biomonitoring in a historical mining district (les Malines, France)

The aim of this study is to investigate the trace elements (TE) contents of potential biomonitors in a historical Zn–Pb mining district: apiary products (honey, royal-jelly and beeswax) lichen and moss were sampled and analysed. In spite of high TE concentrations in mining waste and soil, apiary products are free of TE contamination originating from historical mining. Lichen/moss show high TE levels, which suggest atmospheric input of local dust. Pb isotopes analysis proved the origin of TE found in lichen/moss to be mainly mining waste. These results help discuss the choice of relevant organisms for monitoring TE in the environment and bring additional data on the potential impacts of brownfields left after mining, especially on food products from apiaries.