属性识别理论模型在土壤重金属污染评价中的应用

利用熵权法建立了基于熵权的属性识别模型.采用土壤环境质量标准GB15618-1995,用此模型对南京市六合区的水稻田土壤重金属污染进行评价.实例应用表明属性识别理论应用于土染重金属污染综合评价是可行的,评价结果比较合理.     

基于灰色关联度的土壤环境重金属污染综合评价法

考虑到依据现行土壤环境质量标准(GB15618-1995)的土壤污染评价过程中存在较大的不确定性,将灰色理论引入土壤环境重金属的污染评价中,提出了基于灰色关联度的土壤环境重金属污染综合评价法.将灰色综合评价法应用于现实的案例土壤重金属的污染评价中,结果表明案例区域土壤重金属的8个采样点中只有S1为Ⅲ类土壤,其它样点均为Ⅰ类土壤.灰色综合评价法减少了在土壤污染综合评价中的主观人为因素,并可同时表征同一采样点不同级别和同一级别不同样点之间的土壤环境质量差异,并且在实例研究中发现其可提高预算的有效使用率,是一种可行的评价方法.     

基于Monte-Carlo模拟的土壤环境重金属污染评价法与实例研究

综合分析了现行确定性土壤环境质量评价中的不足,将Monte-Carlo模拟引入地累积指数模型中,并进一步通过数据的挖掘和对土壤中各重金属的生态风险差异的考量,构建了基于不确定性理论的土壤环境质量评价法.将所建方法应用于实例区域,分别构建重金属的实测含量参数和其对应背景值参数的概率分布模型,设定模拟中最大实验量为1 000,置信区间为95%,抽样方法为拉丁超立方(Latin hypercube sampling),得到基于不确定性理论的土壤环境质量评价结果:评价区域土壤中各重金属的污染排序为Cd>Ni>Zn>Cu>Cr,其中,Cd隶属于严重污染等级的概率高达98.1%;Ni和Zn有着明显的空间分布差异,并且属于严重污染的概率也分别达84.5%和87%;Cr和Cu的污染等级相对较低.而后,将所得结果与现行的确定性模型评价结果进行了对比分析,结果表明:所建基于不确定性的评价模型具有更好的评级分辨力,并可更全面、真实地表征该区域土壤重金属的污染特征和概率风险水平.     

桃园土壤重金属污染评价及来源解析

以尉氏桃园为研究对象,对桃园土壤重金属来源进行污染评价及来源解析.通过对表层土壤中4种重金属(Cr、Pb、Zn、As)主成分分析,探讨桃园的土壤重金属形成原因,以无公害果园产地的土壤环境质量标准为依据,应用单因子污染指数法对土壤环境质量进行评价.分析结果表明,研究区重金属元素Cr的含量超出标准限值,且部分样点达到中度污染,此土壤环境质量不符合无公害水果生产的土壤环境质量标准,应给予严格的控制和治理.另外个别样点中类金属元素As的单项污染指数超出了0.7,达到了警戒限状态.主成分分析结果表明,土壤中4种重金属的富集原因存在差异,其中重金属As和Cr主要源于化肥、农药、有机肥的过量施用以及灌溉用水受污染;Zn和Pb主要源于粉尘及汽车轮胎磨损所产生有害气体中的重金属.     

基于重金属化学形态的土壤重金属污染的模糊综合评价模型

综合考虑土壤环境重金属污染的潜在生态风险和受污染土壤中各重金属的生物可利用性差异,建立了基于重金属化学形态的污染场地土壤重金属的模糊综合评价模型.将污染场地土壤重金属的模糊综合评价模型应用于案例污染场地的土壤重金属的污染风险评价中,并将模糊综合评价结果与常用的3种确定性土壤污染评价方法（单因素指数法、潜在生态危害指数法和地累积评价法）的评价结果进行交叉验证,其评价结果与结果间对比分析表明所架构的模糊综合评价模型一定程度上弥补了传统确定性方法的不足,所建模型创新性加入了量化重金属生物可利用性的权重因子,其评价结果具有更高的可信度和风险辨识度,为我国土壤污染的优先控制因子的筛选和相关政策决策的制定提供了科学的理论基础.     

GIS支持下生态环境地球化学质量评价方法探索

对于海量的区域土壤地球化学数据,快速准确的处理与分析评价是其迫切要求。本文根据土壤环境质量标准,结合层次分析法对因子权重进行确定,并采用加权平均型综合指数法进行污染程度分析,结合GIS空间分析技术,对萧山区进行较为系统的环境地球化学质量评价,并重点对该区的重金属元素污染进行了评价。结果表明,萧山区有不同程度的砷、汞、镉、锌、铜和铅重金属污染,尤其以城镇及其城郊尤为严重。     

垫江县农用地土壤潜在重金属毒性污染评价及源解析

通过对垫江县农用地土壤中Zn、As、Cd、Cr、Pb、Cu和Ni等7种重金属的含量进行分析,采用多元统计分析方法解析土壤中重金属的主要来源,并对土壤环境质量进行评价.结果表明:垫江县土壤质量满足《土壤环境质量农用地土壤污染风险管控标准(试行)》(GB 15618-2018)中各风险筛选值要求,多以无风险为主,满足农业对...     

基于标准差因子赋权法的农田土壤重金属潜在生态风险评价

利用标准差因子赋权法改进传统的潜在生态风险评价模型,并对福州市工业园区周边农田土壤中8个代表性采样点中Zn、Pb、Cr、Ni、Cu5种重金属污染的潜在生态风险评价进行实证研究.结果表明,传统法和改进后的模型对该地区土壤重金属综合危害程度的评价均为中等水平,但应用改进法计算的潜在生态危害指数值较传统法均有不同程度的增加,其中5个点位危害程度的等级提高1个级别.因此,标准差因子赋权法改进的潜在生态风险模型对土壤重金属污染的评价精度更高,结果更客观.     

芜湖城市郊区土壤重金属污染综合评价

根据灰色系统基本原理和聚类分析法,提出灰色聚类法,对芜湖城市郊区土壤系统重金属元素污染进行综合评价.此法先确定灰类白化函数,并引入修正系数对白化函数进行修正,避免分级标准值的误判,同时对污染物实测值进行合理的权重处理,由灰色聚类结果表明：鸠江区为Ⅱ级,土壤重金属污染环境质量为尚清洁,其它三个点均为起始污染,其中西江区较好,四山区最差.得出土壤环境综合评价结果与实际污染状况一致,说明运用模糊聚类法是一种适用于土壤污染综合评价的科学方法.     

连云港市水稻产区土壤重金属分布特征及污染评价

为探索连云港市水稻产区绿色优质农产品发展环境条件,依据绿色食品产地土壤环境质量标准,采用单因子污染指数法和综合污染指数法对土壤重金属(镉、汞、砷、铅、铬、铜)污染现状进行了研究.结果表明:重金属镉、汞、砷、铅、铬、铜质量分数都未超过绿色食品产地环境条件土壤重金属质量分数限值,但是东海县和灌云县个别采样点重金属镉、铅单项污染指数接近1;灌南县、赣榆区、市辖区个别采样点重金属铅在0.7～1之间;赣榆区、市辖区个别采样点重金属铜单项污染指数在0.7～1之间.从综合污染指数来看,连云港市水稻产区土壤环境质量评价均为清洁,宜将镉、铅、铜作为日常土壤污染物监测的重点.     

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

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