长江口及邻近海域沉积物重金属分布特征及生态风险评价

调查了2009年长江口及其邻近海域表层沉积物中Cu、Pb、Zn、Cd、Cr、Hg、As的含量,平均含量为Cu 27.88 mg/kg、Pb 22.98 mg/kg、Zn 95.88 mg/kg、Cd 0.178 mg/kg、Cr 41.01 mg/kg、Hg 0.031 mg/kg、As 11.40 mg/kg.空间分布上,Cu、Pb、Zn、Cd、Hg、As 6种重金属含量均在杭州湾北部及长江口南汇交界处呈现最大值,而Cr在调查海域的东部逐渐向近岸海域递减.运用主成分分析评价沉积物中重金属污染来源,同时采用Hakanson指数法评价了沉积物重金属生态风险,结果显示:长江口及其邻近海域表层沉积物中重金属元素的潜在生态风险整体表现为轻微.7种重金属元素对长江口及邻近海域潜在生态综合危害的大小贡献顺序为:Cd＞As＞Hg＞Cu=Pb＞Cr＞Zn.Cd的Eir值对RI值的权重贡献最大,即Cd表现为首要的潜在生态风险因子.     

三门湾沉积物重金属污染及其潜在生态危害评价

沉积物重金属污染对水生生态系统具有潜在危害。对取自三门湾的10个表层沉积物中的重金属(Cu、Pb、Zn、Cd、Hg、Cr、As)元素进行了分析,探讨了其空间分布,运用Hakanson潜在生态危害指数法,评价了表层沉积物中重金属的富集程度和潜在生态风险。结果表明:三门湾表层沉积物中Cu、Pb、Zn、Cd、Hg、Cr、As等重金属含量分布无明显规律;7种重金属中,以Cr的污染程度最高,平均污染系数为1.30,重金属污染程度由高到低依次是:Cr>Zn>Cu>Pb>As>Hg>Cd;潜在生态危害评价显示,重金属元素的潜在生态危害均属轻微,潜在生态危害程度顺序是Hg>Cd>As>Cu>Pb>Cr>Zn,对三门湾生态环境具有潜在影响的重金属元素主要是Hg。     

珠江口红树林湿地海水重金属污染评价及分析

海水重金属是海洋环境质量评价体系中的重要因子,目前珠江口重金属污染问题突出,红树林湿地面积减少,为保护红树林海域环境、改善海水质量,探讨红树林湿地海水重金属的影响因子,对珠江口南沙红树林湿地、淇澳红树林保护区和深圳红树林保护区进行海水采集.通过电感耦气等离子体发射光谱仪(ICP-OES)测定样品中Hg、Cd、Pb、Cr、As、Cu、Zn含量,并基于综合指数法评价海水质量.重金属含量分析与评价结果表明:珠江口红树林湿地海水重金属含量居前的元素是Pb、As、Cd、Hg,含量较少的是Cr、Cu、Zn;综合3个研究区域单项重金属元素的污染程度,由高到低排序为:Hg、Cd、Pb、As、Cu、Cr、Zn;南沙红树林湿地、淇澳红树林保护区、深圳红树林保护区综合指数分别是2.132、13.074、6.398,南沙红树林湿地海水重金属污染为中度污染水平,淇澳、深圳红树林保护区海水重金属污染为严重污染水平;地理位置、潮位流速、红树林湿地生态系统、产业活动影响红树林湿地海水重金属污染程度,而水质要素对红树林海水重金属影响机理较为复杂,需进一步探讨.文中评价珠江口红树林湿地海水重金属污染程度,探讨其影响因子,对保护珠江口红树林湿地有参考价值.     

茅尾海表层沉积物重金属污染及潜在生态危害

利用原子吸收光谱仪和原子荧光分光光度计测定钦州茅尾海表层沉积物中7种重金属元素(Cu、Pb、Zn、Cd、Cr、Hg、As),并采用瑞典学者Hakanson沉积物重金属潜在生态危害指数评价该海域重金属污染程度和潜在生态危害。结果,7种重金属元素含量均小于一类国家标准值,7种重金属潜在生态危害系数和指数均远低于轻微污染上限值。该海域属于较清洁海域。     

钦州市钦江入海排污口邻近海域沉积物重金属污染评价

对钦州市钦江入海排污口邻近海域表层沉积物中重金属的富集状况进行分析,并采用Hakanson潜在生态风险指数法进行评价。结果表明：5种重金属的平均含量分别为Cu（17.0×10-6）、Pb（14.3×10-6）、As（7.63×10-6）、Cd（0.14×10-6）、Hg（0.044×10-6）。沉积物质量评价结果表明：各种重金属的潜在生态危害指数大小顺序为Hg〉Cd〉As〉Pb〉Cu,均属于低潜在生态危害的范畴。     

北京市密云水库上游白河流域土壤重金属含量、来源及污染评价分析

文章对密云水库上游白河流域土壤重金属元素(As、Pb、Ni、Hg、Cr、Zn、Cu、Cd)的空间分布、污染现状及来源进行分析评价。主成分分析和相关性分析结果表明:Cu、Pb和As元素污染来源于矿区金属的开采、选矿和冶炼过程;Zn和Cd主要来源于早期矿石运输汽车尾气的排放及轮胎磨损;Ni和Cr两种元素在该区域的富集主要来源于含重金属垃圾的随意堆放;采用混汞研磨法金矿提炼,导致白河流域矿区周边土壤中Hg元素的富集,造成局部区域出现污染。综合地累积指数及潜在生态危害指数法评价结果表明,Cd、Cr、Zn和Hg的富集程度较高,潜在生态危害较强,应当引起充分关注。     

雪鸡坪-春都铜矿区土壤重金属污染评价

以香格里拉县雪鸡坪-春都铜矿区土壤为研究对象,分析长期采矿活动对表层土壤重金属含量的影响.通过对矿区土壤的重金属(Cd,Hg,As,Cu,Cr,Zn,Pb)含量进行测定,以国家土壤环境质量3级标准和云南省土壤背景值为评价标准,采用内梅罗综合指数法分析矿区土壤的重金属污染现状,运用Hakanson潜在生态危害指数法进行潜在生态风险评估.结果表明:矿区长期开采活动导致Hg,As,Pb,Zn,Cu这5种重金属含量高于云南省土壤背景值,Hg,As,Pb,Zn,Cu,Cd这6种重金属含量高于全国土壤背景值;Cu的单因子污染指数值最高,污染水平超标,为该矿区土壤的主要污染元素;综合土壤环境指数为1.14,土壤受到轻度污染;矿区Hg元素具有强的生态危害,Cu元素具有中等生态危害,其余元素为轻微生态危害,综合生态危害指数为226.22,整体上该矿区的生态风险属于中等水平.     

广西茅尾海海水和表层沉积物中重金属污染的调查及评价

2011年10月从钦州茅尾海采集19个海水样品和16个沉积物样品,利用原子吸收光谱仪和原子荧光分光光度计测定钦州茅尾海表层沉积物中6种重金属元素(Cu、Pb、Zn、Cd、Hg、As)含量,采用单因子指数法和Hakanson生态风险指数法对海水及表层沉积物重金属污染特征及潜在生态风险性进行分析和评价.结果表明:该海域海水中Cu、Pb、Zn、Cd、Hg、As的含量(μg/L)变化范围分别为0.9～4.2、0～12.8、0～59.8、0.03～0.34、0～0.105、0.23～0.82,平均浓度(μg/L)分别为2.2、2.3、17.4、0.13、0.047、0.43,其中,海水中的Pb平均含量超过国家一类海水水质标准,各种重金属单因子污染程度依次为Pb＞ Hg＞Zn＞Cu＞Cd＞As.表层沉积物中的Cu、Pb、Zn、Cd、Hg、As的含量(μg/L)变化范围分别为(2.1～46.5)×10-6、(13.9～34.0)×10-6、(21.4～114.1)×10-6、(0.06～0.40)×10-6、(0.001～0.126)×10-6、(3.77～19.63)×10-6,平均含量(μg/L)分别为18.1×10-6、26.3×10-5、56.7×10-6、0.19×10-6、0.056×10-6、9.60×10-6.该海域重金属综合污染程度和潜在生态风险性均较低,重金属元素污染程度Cu＞ As＞Pb＞Cd＞ Zn＞ Hg,重金属元素对海洋生态系统潜在危害的影响程度Cd＞Hg＞As＞Cu＞Pb＞Zn,沉积物中主要潜在生态风险因子为Cd、Hg.     

胶州湾水环境重金属立体分布、污染及风险

为探讨胶州湾水环境中重金属的立体空间分布、污染及风险,分别采集深度为0~10m(表层),10~20m(中层)和20~30m(底层)的海水与海底表层(0~10cm)沉积物样本,测定8种重金属(As,Cd,Cr,Hg,Zn,Pb,Cu和Ni)在水体中的质量浓度(mg/L)和沉积物中的质量分数(mg/kg),基于国家海水水质标准和水质质量指数法、海洋沉积物质量标准和Hakanson潜在生态危害指数法评价了海水和沉积物中重金属的立体分布、污染及其潜在生态风险.结果表明:胶州湾海水重金属质量浓度除Cu,Hg,Ni和Pb外,均未超出IV类标准;相对污染指数值由大到小依次为Cu,Pb,Hg,Ni,Cd,Cr,Zn,As,其中Cu,Pb,Hg,Ni和Cd达到严重污染水平,综合污染指数测算表明胶州湾海水重金属污染严重.就胶州湾海水重金属的平面分布而言,其高值区出现在湾东和西南区,其中Hg高值区沿胶州湾大桥分布.就胶州湾海水重金属的垂直方分布而言,0~10m的表层海水和20~30m的底层海水中重金属质量浓度均高于10~20m的中层海水.除Cr外,沉积物中其他重金属质量分数均高于海洋沉积物的I级质量标准,潜在生态风险指数由大到小依次为Hg,As,Ni,Cd,Pb,Cr,Cu,Zn,并呈现出东高西低、沿污染源分布的特点.     

海州湾北部沉积物重金属来源解析及污染评价

基于海州湾北部海域15个采样站位表层沉积物7种重金属含量(As、Hg、Cu、Pb、Zn、Cr、Cd)测定,研究了重金属空间分布特征,采用主成分分析法解析重金属来源,应用地累积指数法和潜在生态风险指数法评价重金属污染程度和生态危害程度.结果表明:Cd、Pb、Zn、Cu和As 5种元素平均含量超过江苏海涂背景值,分别是背景值的2.62、2.58、1.80、1.35和1.24倍,存在明显的富集.研究区重金属来源以自然来源为主,Cr和Hg受自然来源控制;Zn、As、Cd和Cu主要来源于工业、农业和生活污染;Pb来源于船舶污染.地累积指数法评价结果显示,Pb和Cd地累积指数高于其他元素,为轻度—偏中度污染.潜在生态风险指数法评价结果显示,研究区总体处于低生态风险水平,Cd为主要风险元素,达到中—较高生态风险水平,其他元素均为低风险.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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