甲基汞的荧光测定方法研究

建立了测定甲基汞的荧光分析法,该方法是基于罗丹明Ｂ与甲基汞的碘络阴离子形成离子对化合物,然后用苯萃取;激发波长为５７５ｎｍ,发射波长为５９０ｎｍ;方法的线性范围为４＊１０＾－８－５＊１０＾－７ｍｏｌ／Ｌ,相关系数为０．９９７９,检出限为２μｇ／ｍＬ。该方法已用于人发中甲基汞的测定,回收率为９６％－１０５％,相对标准偏差为４．２％。     

气相色谱测定鱼体的痕量甲基汞

鉴于甲基汞的生物毒性效应并通过食物链而危害人类健康这一事实,因此我们必须建立一个准确、性速测定鱼中甲基汞的方法。目前,甲基汞的测定方法主要采用气相色谱电子捕获法,但在测定甲基汞很低的生物样品时灵敏度不够,误差较大。因此,对生物样品的前处理需进一步改进。测定甲基汞的样品前处理目前仍基于Gagc的Westoo改良法,多采用琉基乙酸、半胱氨酸溶液或硫酸酯纯化。用苯或甲苯进行萃取和半胱氨酸滤纸富集再用苯洗脱,使甲基汞得到富集和净化,并建立了气相色谱测定甲基汞的方法优劣进行评价分析。一、试验1.主要化学试剂及仪器。氮气:纯度…     

甲基汞对大鼠大脑皮层即刻早期基因c-FOS蛋白表达影响

为了探讨甲基汞对大鼠大脑皮层损伤的分子机制,应用免疫组织化学方法研究了甲基汞暴露后（对照组为ω=0．009的生理盐水,暴露组浓度分别为0．05、0．5、5μg／g;取样时间分别为20、60、240、1440min）,大鼠大脑皮层即刻早期基因c-FOS蛋白表达变化．结果表明,大鼠脑c-FOS蛋白表达优先于汞的蓄积,甲基汞对大鼠大脑皮层c-FOS蛋白表达与其浓度之间有一定的剂量一效应关系;c-FOS参与了甲基汞对大鼠大脑皮层损伤毒性过程,即刻早期基因c-FOS可以作为甲基汞神经毒性检测评价效应指标．     

乌江上游水域水生生物中甲基汞污染调研

本文对乌江上游水域及主要支流猫跳河、六冲河的水生生物体甲基汞含量进行了研究,从六个采样点获得十种鱼及虾、螺和水草样,利用气相色谱分别测定了鱼样的肉、肝、鳃及虾、水草样中的甲基汞含量,其中鱼体甲基汞含量为0.035—0.135ppm,甲基汞平均含量为0.103ppm,螺,虾为0.014ppm,水草样<0.002ppm,实验方法的回收率为89—112％,相对标准偏差为6.17％。     

基于金-汞纳米颗粒可视化检测海产品中的甲基汞

基于特定序列的DNA对甲基汞的特异性识别作用,通过晶种生长法经两步还原形成金-汞纳米颗粒,依据颜色从无色到紫红色变化的原理,建立一种非标记且高特异性的甲基汞快速可视化检测体系,并应用于海产品中甲基汞的检测.实验考察不同DNA序列对甲基汞的识别特异性,选择HT9 DNA为最优的识别序列.在最优实验条件下,甲基汞浓度在0.05～4.00μmol·L~(-1)范围内与吸光度呈现良好的线性关系,其检出限为0.01μmol·L~(-1).采用所建立的方法测定海带、鲍鱼、小黄鱼等海产品加标样品中的甲基汞浓度,样品加标回收率为90.4%～97.0%.同时利用IC-ICP-MS对相同样品中甲基汞浓度进行检测,获得较为一致的结果.     

基于金-汞纳米合金可视化检测海产品中的甲基汞

本论文基于特定序列的DNA对于甲基汞的特异性识别作用,通过晶种生长法经两步还原形成金-汞纳米合金颗粒,从而发生从无色到紫红色的颜色变化。随着甲基汞浓度的升高,生成的金-汞纳米合金浓度越高,颜色变化越明显。基于上述原理,建立了一种非标记的甲基汞快速可视化检测体系并用于海产品中甲基汞的检测。实验考察了不同序列DNA对甲基汞的识别特异性,选择了HT9 DNA作为最优的识别序列。最终所测得的金-汞纳米合金在550nm 处的吸光度值与甲基汞浓度在0.05 μM到4.0 μM范围内与呈现良好的线性关系。通过目视法可检测低至0.2 μM的CH3Hg+,通过仪器的检测限（3σ/k）为0.01 μM ,且对于甲基汞检测具有很高的特异性。采用所建立的方法测定了海带、鲍鱼、小黄鱼等三种海产品加标样品的甲基汞浓度,样品加标回收率为90.3-96.9%,同时实验还利用IC-ICP-MS对相同样品中甲基汞浓度进行检测,获得了较为一致的结果。     

吹扫捕集/气相色谱-冷原子荧光光谱法测定水中烷基汞

建立了全自动烷基汞分析仪测定废水中烷基汞(甲基汞和乙基汞)的方法,实验中所用的衍生化试剂(四丙基硼化钠)与水样直接反应进入气相色谱柱中分离并高温裂解,最后进入冷原子荧光检测器(CVAFS)检测烷基汞的含量。当取样体积为45mL时,甲基汞和乙基汞的检出限均为0.02ng/L,线性良好,对烷基汞检测器分析方法的可靠性进行了精密度和准确度实验,研究了衍生化试剂的加入量和载气流速对烷基汞测定的影响,优化了实验条件。     

丁基罗丹明B萃取分光光度法测定甲基汞

本文研究了丁基罗丹明B阳离子和CH_3HgBr_2~-阴离子生成缔合物的条件和组成,建立了测定痕量甲基汞的新方法.     

自动固相萃取-气相色谱法测定水中的烷基汞

采用自动固相萃取-气相色谱-ECD检测器测定水中的烷基汞(甲基汞、乙基汞)。选用ULBON HR-Thermon-HG色谱柱测定烷基汞具有峰形尖锐对称,分离效果持久的特点。该方法具有良好的精密度和准确度,检出限低,操作简便,可用于地表水、城镇污水等样品中烷基汞的测定。     

磷掺杂类石墨相氮化碳的制备及其在甲基汞检测中的应用

甲基汞在环境中对生物危害极大,因此迫切需要一种快速高灵敏的检测方法.本文通过将磷掺杂到类石墨相氮化碳(g-C3 N4)中,减小了其禁带宽度,提高了其催化活性.采用磷掺杂类石墨相氮化碳(PCN)修饰金电极构建了电化学传感器用于甲基汞(CH3 Hg+)的测定.在最佳实验条件下,CH3 Hg+展示出良好的差分脉冲伏安响应信号...     

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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