太原市干沉降中PAHs污染特征及生态风险研究

研究使用大气干湿沉降自动采样仪于2013年8月至2014年10月采集了太原市30个大气干沉降样品,并对15种USEPA优控多环芳烃(PAHs)的污染特征和来源及生态风险进行了研究。结果表明太原市干沉降中∑15-PAHs的水平为(8.19～62.31)μg/g,均值为24.37μg/g,污染水平较高;PAHs主要组成成分为Phe、Fla、Pyr和chr,环数以3、4环为主。特征比值法和主成分分析结果显示太原市干沉降中PAHs的三大主要来源为燃煤、机动车和焦化产业。干沉降通量和∑15-PAHs的干沉降通量范围分别为(157.44～358.17)mg/(m²·d)和(2 436.20～13 616.80)ng/(m²·d),太原市全年颗粒物和∑15-PAHs沉降量为6.89×10⁵ t和18.18 t.干沉降中PAHs的毒性当量浓度范围为(0.67～2.94)μg/g,均值为1.55μg/g.生态效应区间法评价结果显示82.76%的干沉降样品所含PAHs生态风险水平较高,应引起高度重视。     

太湖北部湾沉积物中多环芳烃分布及风险评估

以EPA优控的16种多环芳烃为对象,分析了太湖北部贡湖的大贡山(1号采样点)和小贡山(2号采样点)以及梅梁湖的马山(3号采样点)和拖山(4号采样点)不同季节16种多环芳烃的分布特征及风险,并采用特征化合物及多元统计分析方法分析了多环芳烃的来源.结果表明:春季受周围工业生产影响,多环芳烃质量比较高,质量比在342.1～611.1ng/g之间;夏季受高温及引江济太调水工程影响,梅梁湖多环芳烃质量比下降,而贡湖1号与2号采样点出现全年最大值,质量比分别为558.4ng/g与335.6ng/g;冬季梅梁湖2个采样点多环芳烃质量比变化较小,贡湖则出现全年最小值,质量比分别为248.8ng/g与340.5ng/g.太湖北部湾中多环芳烃尚未对周围环境造成明显的不利影响.油料、木材和煤炭燃烧是多环芳烃的主要来源.     

石河子市大气总悬浮颗粒物的浓度和其中多环芳烃的分析

为探讨总悬浮颗粒物通过干湿沉降进入陆地、水生生态系统造成危害,而其中的多环芳烃具有毒性、致癌性,因此日益受到人们的关注。选取石河子地区5个采样点的TSP作为研究对象,于2014年进行了样品的采集工作,用气相色谱-质谱联用仪(GC-MS)对PAHs进行测定。研究结果显示,石河子平均TSP水平(257.83μg/m3)高于世界卫生组织的标准(80μg/m3)和美国环保总局的标准(60μg/m3)。石河子市PAHs浓度最大值出现在冬季(134.9ng/m3),最小值在夏季(20.6 ng/m3);PAHs平均浓度最大的采样点是工业园区,石河子市检出的苯并(a)芘(Ba P)平均浓度为3.21-9.21 ng/m3,已经超出世界卫生组织的标准(1 ng/m3),对Ba P与PAHs总浓度进行线形回归分析可知,机动车尾气是石河子市总悬浮颗粒物中多环芳烃的主要污染源。     

西江水体中多环芳烃的分布特征

采用玻璃纤维滤膜过滤分离西江水柱样品,并根据气相色谱一质谱联用(GC-MS)对多环芳烃(PAHs)进行定量分析.结果表明,溶解相和颗粒相中多环芳烃的浓度分别为21.7～138 ng·L-1和40.9～238μg·kg-1.水体中多环芳烃的总含量(颗粒相及溶解相),洪水期(43.9～116.9ng·L-1)大于枯水期(25.2～34.1 ng·L-1).从PAHs组成特点来看,溶解相以3环的PAHs为主,占总组分的80%;而颗粒相以3环、4环的PAHs为主,分别占总组分的48%和41%.西江水体多环芳烃的总含量,高于欧洲一些低污染水域,但低于国内一些主要河流.     

土卫六Titan大气中多环芳香烃PAH分子

土卫六(Titan)是土星的最大一颗卫星,也是太阳系第二大卫星.它是太阳系唯一一颗拥有浓厚大气层的卫星.其大气层富含氮气(N2,体积比占98%),少量甲烷(CH4,占2%)以及其他微量有机分子(如乙炔C2H2).最近,卡西尼(Cassini)宇宙飞船上的VIMS光谱仪对土卫六的大气层作了光谱观测,探测到源自多环芳香烃(PAH)分子的3.28?m发射特征.PAH是星际介质的重要成分,也常被认为是土卫六上空橘红色的烟雾层(Haze)的重要成分.PAH分子如何在土卫六大气中形成是行星科学的一个难解之谜.本文从星际空间、太阳系的PAH分子研究着手,介绍了Titan的大气中多环芳烃PAH分子的观测特性、化学结构、形成机制及未来趋势.     

陕西关中地区大气氮湿沉降特征分析

为了进一步了解陕西关中地区大气氮沉降的变化特征，采用降水采集法对宝鸡2018年大气氮湿沉降进行了观测，并对雨水中可溶性无机氮浓度及沉降通量的动态变化进行了分析.结果表明：(1)雨水中NH₄⁺-N和NO₃^--N月平均质量浓度为1.581 mg/L和1.369 mg/L，且降水量少的月份雨水中氮素浓度较高；(2)NH₄⁺-N和NO₃^--N在雨水中的季浓度均呈现冬季高、夏季低的趋势；(3)大气氮湿沉降通量为9.728 kg/(hm²·a)，其中NH₄⁺-N和NO₃^--N分别占53.6%和46.4%，且降水量多的季节氮沉降通量也相应较高；(4)大气氮总沉降通量达23.713 kg/(hm²·a)，约占当地农田氮肥施入的10%.     

太湖饮用水源地多环芳烃分布特征和溯源分析

持久性有机污染物引起的水质安全性问题日益受到广泛关注.为探究太湖饮用水源地多环芳烃的污染情况,对太湖饮用水源地表层沉积物进行了采样,对多环芳烃进行了定量检测,分析了研究区沉积物中多环芳烃浓度分布,同时采用2种方法(特征化合物法和主成分分析法)进行溯源分析.结果表明:太湖饮用水源地表层沉积物检测出11种PAHS,总量介于nd~280ng·g-1之间,平均值为114ng·g-1.和国内外其他湖泊、河口及海湾地区相比,太湖饮用水源地PAHs污染处于低水平.太湖饮用水源地表层沉积物PAHs组成以4环及5~6环PAHs为主(分别为43.86%和50.88%),2~3环PAHs相对较低(5.26%).太湖饮用水源地表层沉积物PAHs主要来源为化石燃料(包括汽油、柴油、煤、木柴等)的燃烧,但也与石油污染有关.本文成果可为太湖流域水污染防治和水资源管理提供科学参考.     

基于GIS的河北平原土壤Se年增长量估算

利用多类样品数据对河北平原Se元素的输入输出通量进行了空间分析,并在此基础上对土壤Se的年增长量进行了估算.结果显示:在河北平原,大气干湿沉降为土壤中Se主要输入方式,输入通量达到5. 88 g·(hm~2·a)~(-1),灌溉水和化肥输入通量较低,通过粮食籽实输出通量极小,研究区Se属于净输入的形势.河北平原Se净增量均值为3. 4μg·kg~(-1).由于大气干湿沉降的分布较均匀,Se净增量的区域分布差异由灌溉水输入决定,整体上形成山前和滨海地区两个高净增量区域;除此之外,各地工业结构,以及土壤类型等也会影响了当地Se的净增量,如城市Se净增量高于农村,化工城市Se净增量高于其他城市,适宜农作物生长的土壤类型的Se净增量低于不适宜农作物生长的土壤类型.     

西安冬季可吸入颗粒物中多环芳烃的组成及风险评价

对2006-12-19～至2007-01-15采集的西安冬季昼夜大气可吸入颗粒物(PM_(10))样品,利用气相色谱-质谱联用仪(GS-MS)分析检测出美国EPA优先控制的12种多环芳烃(PAHs),结果显示,西安冬季大气PM_(10)中白天与夜晚总的PAHS平均质量浓度分别为312.0 ng·m~(-3)和346.0 ng·m~(-3),且PM_(10)中主要以4～5环的多环芳烃为主.采用苯并(a)芘(BaP)等效质量浓度(BaPE)评价PAHS的污染状况,结果表明,苯并(a)芘(BaP)白天及晚上的平均质量浓度分别为30.0 ng·m~(-3)和34.8 ng/m~3,计算得出西安冬季白天与晚上的BaPE平均值分别为45.3 ng·m~(-3)、51.0 ng·m~(-3),含量超过国家标准4.5倍以上.     

水中多环芳烃混合物快速恒能量同步荧光分析

建立了咔唑、1,2-苯并蒽、苯并[a]芘和2,3-苯并蒽四种多环芳烃同时快速测定的恒能量同步荧光分析法.选择能量差Δυ-=1400cm-1,仅需一次扫描,就可同时鉴别和定量测定四种多环芳烃.四种多环芳的线性范围依次为0.5-300ng·mL-1、0.2-250ng·mL-1、0.05-50ng·mL-1和0.5-350ng·mL-1,检出限在0.0046-0.023ng·mL-1之间.该方法简单快速、灵敏度高,无需对多环芳烃混合物进行预分离,可用于实际水样的直接分析,效果良好,回收率为83.0%-105.3%.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

正~~