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1.
2005年10月对水东港及其近岸海域海水和海洋生物体进行采样,测定海水中重金属(A s、Hg、Pb、Cd和Cu)和海洋生物体内重金属(Cu、Pb、Cd、Hg、C r、Zn和N i)含量,其中海水重金属含量采用单项污染指数评价法进行评价,海洋生物体内重金属含量采用生物质量指数法进行评价,海洋生物的无公害评价按照国家农业行业标准进行评价,海洋生物对重金属的富集状况通过生物体对某种重金属的富集系数来评价。结果表明:水东港及其近岸海域海水中A s、Hg、Pb、Cd和Cu的含量均低于渔业水质标准和海水水质标准,总体质量为优质;水东港及其近岸海水中海洋生物体内重金属的含量均低于海洋生物污染评价标准,但是各类生物体内的Pb和Cd的含量均超过国家无公害标准;各类海洋生物对于Cd比其它重金属具有较强的富集能力。  相似文献   

2.
海水中痕量铜的双Sep-Pak柱FIA在线预富集和FAAS检测   总被引:1,自引:0,他引:1  
采用配有双Sep-Pak柱的流动注射分析仪在线预富集海水样品中痕量铜的8-羟基喹啉络合物,经甲醇洗提后,由火焰原子吸收光谱仪检测,对100ml海水样品的富集倍率可达2个数量级,富集检测速率可为10次/h。多次富集测定的重现性在2.0~5.7%范围内,测定了铜含量在3~7ng/ml浓度范围内的海水样品。  相似文献   

3.
本文采用双柱同时进行在线流动注射离子交换预富集测定痕量铜。在采样频率为120个样次/小时的速度下,富集倍数为18倍,检出限为0.2μg/l(3δ),对等30μg/l铜标准液相对标准验差为1.9%、2.0%。  相似文献   

4.
湿地松对铜胁迫的生理耐性及富集特征   总被引:1,自引:0,他引:1  
以湿地松幼苗为材料,于2016-2017进行盆栽试验,分析湿地松在铜胁迫下的生理响应及富集特征。结果表明:随着铜处理浓度的增加,过氧化物酶(POD)活性持续上升,超氧化物歧化酶(SOD)活性先升后降,过氧化物酶(CAT)变化与POD一致,丙二醛(MDA)含量上升。根是铜主要的吸收器官,各器官对铜的富集能力表现为根茎叶,随着铜处理浓度的增加,转运系数表现为先减后增,且在铜处理为20 mmol/L时达到最大值为0. 64。表明湿地松对低浓度的铜具有较强的富集特征,对高浓度的的铜富集能力较弱,湿地松对重金属铜有一定的耐性,但不是超富集重金属铜的树种。  相似文献   

5.
研究表明对生物体有直接作用的金属并非溶解态的全部,而是其中的活性部分.薄膜扩散梯度技术(DGT)作为一种原位富集有效态金属的新技术,被广泛应用于自然水体里重金属的分析.本研究设计了一种能同时原位富集海水中的Mn、Co、Ni、Cu、Zn、Cd、Pb的DGT装置;使用自制的凝胶扩散系数测定装置获得了金属离子在扩散相凝胶中的扩散系数;考察了pH、离子强度等对富集效果的影响,当pH为5.6~8.6、离子强度在10~700mmol/L范围内,富集效果不受影响.在厦门近岸海域成功地进行为期7d的海水中重金属的原位富集,实验结果显示,DGT能够富集该海域海水中6.672%~45.33%的溶解态重金属,即获得DGT有效态.平行样测定的相对标准偏差均小于10%,该方法可用于海水中痕量有效态重金属的分析.  相似文献   

6.
海水中溶解态磷酸盐的氧同位素组成(δ18Op)是海洋磷循环研究的有效示踪剂之一.海水中溶解态磷酸盐的富集、分离与纯化研究是测定海水磷酸盐氧同位素组成的基础.通过对国内外海水中磷酸盐氧同位素组成的测定方法进行查阅,选择改进后的MAGIC-CePO4沉淀-阳离子交换树脂法对海水中溶解态磷酸盐进行富集、分离与纯化,并对实验条件进行了探讨.实验结果表明,所采用的方法对于3种不同溶液体系3个步骤的磷酸盐平均回收率分别为92.8%,88.2%和98.3%,全流程磷酸盐回收率达到80%以上,因此可作为海水磷酸盐氧同位素测定的重要前提.  相似文献   

7.
为研究激振力对分选废旧电路板中金属分布规律和金属回收率的影响,采用自制高频气力分选机分选0.75~0.125 mm废旧电路板粉末,通过ICP-AES测定分选产品.结果表明:当激振力在操作范围内变化时,铜的分布规律明显,最高富集比为7;密度比铜密度大和与铜密度相近的金属如铅、锌等富集效果明显,分布规律与铜的分布规律相似;密度比铜密度小很多的金属如铝、镁等富集效果不明显,错配率较高.高密度金属(铅、锌、锡)的回收率都比较高,最高回收率都在88%以上;但低密度金属(铝、镁)的回收率很低,最高仅为31.72%和32.37%,所以若要分离富集该类金属,须对分选后的物料进行二次分选.  相似文献   

8.
一株高耐铜菌株的分离及富集特性研究   总被引:1,自引:0,他引:1  
从安徽铜陵铜尾矿土壤中筛选到一株对铜具有较强抗性并具有较强富集能力的丝状真菌,根据其形态特征初步鉴定为曲霉属.对铜离子浓度与菌体生长以及影响富集量的因素进行了研究,结果表明:在pH 4.4,初始铜离子浓度50 mg/L,培养时间为72 h,最大富集量为12.87 mg/g干菌体,对铜的最大去除率为84.65%.  相似文献   

9.
分别对中华白海豚栖息地的海水、表层沉积物和生物(鱼类、甲壳类和软体类动物)体中的重金属含量进行测定与污染评价.结果表明,海洋生物对海水和沉积物中重金属有较强的富集能力,中华白海豚其肝脏中高浓度的重金属含量是通过食物链(网)而逐级积累的.栖息地中海水质量介于海水I类与II类水质之间,表层沉积物质量符合I类标准,3类不同类...  相似文献   

10.
驯化活性污泥富集高盐度废水中金属离子的研究   总被引:1,自引:0,他引:1  
以城市污水处理厂的剩余活性污泥为初始原料,通过驯化后研究其对某矿山废水中的Cu(Ⅱ)、Zn(Ⅱ)两种金属离子的富集.结果发现,经驯化后的污泥可很好地起到对该废水中金属离子的预富集.在室温下,活性污泥质量浓度(MLSS)为3.1 g·L-1的每升驯化活性污泥能够富集大约493mg的铜和305 mg的锌.污泥的驯化盐分和富集时的pH值对富集率影响较为重要.与常规的活性污泥吸附淡水中金属离子实验相比较,驯化污泥的富集速率和方式都有较大变化.  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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