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1.
采集了某铀尾矿库区夏季大气颗粒物(TSP、PM2.5),检测分析了颗粒物质量浓度及铀、重金属(Pb、Cd、Cu)含量,结果表明:TSP的质量浓度为53.9μg/m3,PM2.5的质量浓度为28.0μg/m3,TSP与PM2.5的质量浓度的相关系数R=0.832 2;TSP中铀的含量为0.078μg/m3,PM2.5中铀的含量为0.025 6μg/m3;TSP中Pb、Cd、Cu的含量分别为0.111 2μg/m3、0.014 9μg/m3、0.179 7μg/m3,PM2.5中Pb、Cd、Cu的含量分别为0.063 9μg/m3、0.007 4μg/m3、0.038 1μg/m3;TSP中重金属含量由高到低的顺序是Cu>Pb>Cd,PM2.5中重金属含量由高到低的顺序是Pb>Cu>Cd。  相似文献   

2.
【目的】针对广西近岸海域重金属污染越来越严重的问题,研究红树白骨壤幼苗对水中重金属(Cu,Pb,Zn,Cd)的吸附去除性能。【方法】红树白骨壤幼苗采用砂培法由胚轴栽培而得,配制不同浓度混合重金属培养液对红树白骨壤幼苗胁迫培养35d后采用原子吸收光谱法测定其体内的重金属含量。【结果】随着培养液中重金属浓度的升高,红树白骨壤幼苗体内的重金属含量也逐渐增加,最高含量分别达到Cu 980.78μg/g,Pb 1623.03μg/g,Zn 446.21μg/g,Cd 69.41μg/g。红树白骨壤幼苗不同部位对重金属的积累能力普遍是叶部最少,茎部次之,大部分都积累在根部。红树白骨壤幼苗的根、茎对Zn的输送能力最好,其次是Cu和Cd,对Pb的输送能力最差。【结论】红树白骨壤幼苗对4种重金属都有较好的吸附能力,尤其是对Pb和Cu的吸附去除效果更好,是一种性能良好的近岸河口重金属污染修复植物。  相似文献   

3.
采集了重庆不同城市功能区的主要苔藓类型,分析了其重金属(Cu,Zn和Cd)含量,并选择几种分布较广苔藓进行重金属等温吸附试验.结果表明,重庆城区苔藓中Cu,Zn和Cd三种重金属含量因所处城市功能区的不同而不同,工业园区苔藓中重金属的含量是自然保护区的2~3倍.地钱属苔藓对三种重金属的都具有较强的富集能力.对Cd的富集能力最强,其次是Zn和Cu.Cu,Zn和Cd在苔藓植物体内的含量都具有显著的正相关关系(p<0.01).几种苔藓植物对三种金属离子的等温吸附可以很好的用Freundlich和Temkin方程进行拟合.由Langmuir方程计算苔藓植物对重金属的最大吸附量,结果表明:白发藓属对铜的吸附量最大,为4.71mg/g.地钱属对锌的吸附量最大,为4.13mg/g.小锦藓属对镉的吸附量最大,为4.39mg/g.显示出较强的重金属吸附能力,可作为城区大气污染的指示生物.  相似文献   

4.
浙江自然海域养殖贝类3种重金属含量分析与评价   总被引:1,自引:0,他引:1  
运用原子吸收法对2009年6-10月所采集的浙江自然海域68个样品中重金属Pb、Cu、Cd含量进行了分析,研究了贝类体内重金属的含量和累积,对不同海区的贝类生物体中重金属含量进行了比较,对贝类的质量安全进行了评价。结果表明:泥蚶、缢蛏、紫贻贝和牡蛎体内重金属含量大小顺序均为Cu〉Cd〉Pb,而青蛤的含量大小顺序为Cu〉Pb〉Cd。5种贝类体内重金属含量Cu最高。不同贝类品种间重金属累积存在明显差异,泥蚶含Cd量最高,牡蛎含铜量最高。缢蛏、紫贻贝和青蛤体内重金属含量处于正常范围和轻污染水平,但部分泥蚶体内Cd为重污染水平,部分牡蛎体内Cu为严重污染水平,其食用安全性存在一定风险,应该引起政府部门高度重视。  相似文献   

5.
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.  相似文献   

6.
海藻粉用量对重金属离子吸附率的影响   总被引:5,自引:0,他引:5  
探讨了金属离子浓度,藻粉用量对2种常见大型海藻马尾藻(Sargassumfusiforme)和海带(Laminariajapon ica)吸附重金属离子(Cu2 、Pb2 、Cd2 、Ni2 )的影响.结果表明,100mg/L以内,海带对Pb2 的吸附率保持在99%以上,对Cu2 、Cd2 保持在90%以上;50mg/L以内对Ni2 的吸附保持在90%以上.藻粉对重金属离子的吸附率,随藻粉投入量的增加而增加,而单位重量藻粉的吸附量却随藻类浓度的增加而减少.选择藻粉的投入量在2.5g/L,既能够达到对各种离子良好的吸附.  相似文献   

7.
成都市城市土壤中重金属的现状评价   总被引:19,自引:0,他引:19  
成都市城市土壤的研究显示,土壤中Hg,Cd,As,Cr,Pb,Cu,Zn含量分别为0.31μg/g,0.36μg/g,11.0μg/g,60μg/g,76.9μg/g,42.0μg/g,224μg/g,研究区范围内土壤中重金属平均含量除Cd外,均低于国家土壤二级质量标准。Tessier连续提取法镉形态分析结果表明,镉可交换态含量比例高达33.16%。与国内外其它城市比较,Hg含量较高;Cr,Cu,Zn含量处于中等水平;Cd,As,Pb含量水平相对较低。主要污染来源与工业布局、燃煤、交通、乡镇企业分布等因素有关。  相似文献   

8.
于2006年4月采集厦门九龙江河口水样,测定其溶解、颗粒态Cu、Pb、Cd及相关水化学参数的含量.结果表明,厦门九龙江河口区表层海水中溶解态Cu、Pb、Cd的含量范围分别为0.96~2.16、1.02~2.49及0.16~0.44μg/L,平均值分别为1.52、1.60和0.34μg/L;颗粒态Cu、Pb、Cd的含量范围分别为0.26~3.40、0.11~6.00、0.000 4~0.028 0μg/L,平均值分别为1.08、1.61和0.0064μg/L.在垂直变化上,除Cd变化较小外,Cu和Pb浓度随深度增加而逐渐升高,其贡献主要来自底部沉积物再悬浮.九龙江河口溶解和颗粒态Cu、Pb、Cd的平均入海通量分别为6.57、6.91、1.47、4.66、6.96和0.027 kg/d.九龙江河口区表层水体中Cu、Pb、Cd的表观分配系数(Kd)分别为4.09、2.84和0.10 L/kg.3种金属在研究海域的固-液分配机制主要受“颗粒物浓度效应”影响,而Cd在低盐度区受到“盐度效应”的影响.  相似文献   

9.
在静水实验条件下,研究了不同饵料种类和浓度对太平洋真宽水蚤存活率、产粪数和产卵量的影响。结果表明:在食物碳含量为1.0 mg C/L的条件下,不同饵料投喂后,太平洋真宽水蚤的存活率、产粪数和产卵量有明显的差异(P0.05)。投喂亚心形扁藻、中肋骨条藻和三角褐指藻的存活率高于球等鞭金藻和小球藻(P0.05);投喂中肋骨条藻的产粪数明显高于投喂其他4种单胞藻的产粪数(P0.05);投喂亚心形扁藻和中肋骨条藻的产卵量明显高于小球藻(P0.05),其他饵料种类的产卵量无显著差异(P0.05)。实验进一步研究了不同浓度亚心形扁藻和中肋骨条藻对太平洋真宽水蚤生物学的影响,结果表明:不同浓度的亚心形扁藻对太平洋真宽水蚤的产卵量无显著影响(P0.05);不同浓度的中肋骨条藻对太平洋真宽水蚤的存活率、产粪数和产卵量差异性显著,且随着浓度的升高其存活率、产粪数和产卵量逐渐减少(P0.05)。投喂亚心形扁藻和中肋骨条藻饵料浓度为2.0 mg C/L时效果最好,表明此浓度条件下的亚心形扁藻和中肋骨条藻是太平洋真宽水蚤相对适宜的饵料,可为人工培养太平洋真宽水蚤作为水产活体生物饵料奠定基础。  相似文献   

10.
厦门白鹭保护区白鹭体内重金属含量的分析   总被引:6,自引:1,他引:6  
采用原子吸收法测定及比较厦门白鹭自然保护区鸡屿岛的白鹭(Egrettagarzetta)雏鸟和成鸟体内铅(Pb)、镉(Cd)、铜(Cu)、锌(Zn)的含量.结果显示,4种重金属在白鹭肌肉和羽毛组织中的含量都是Zn>Cu>Pb>Cd;白鹭成鸟羽毛中Pb、Cd、Cu、Zn的含量分别为6.029±0.005,0.356±0.100,7.269±1.452,117.275±63.420(μg/g干质量);成鸟肌肉组织中的4种重金属含量高于雏鸟.提示白鹭体内重金属含量随着分布地区、年龄和器官组织的不同而发生变化,重金属随着年龄增长而产生富集,厦门白鹭体内的Pb、Cd、Zn含量高于香港米埔和法国Camargue区域.  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
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-  相似文献   

18.
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-  相似文献   

19.
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  相似文献   

20.
<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  相似文献   

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