微波消解-火焰原子吸收光谱法测定淇河鲫鱼中铅含量

应用微波消解仪和原子吸收分光光度计,采用原子吸收光谱法测定鹤壁特产淇河鲫鱼鱼肉中的铅含量,回收率为93%～108%,相对标准偏差小于10%。对微波消解和原子吸收分光光度法的测定条件进行了探讨和研究。     

微波消解-氢化物发生-原子荧光光谱法测定土壤中的铅

尝试用微波消解的方法代替传统的消解方法,用氢化物发生-原子荧光光谱法(HG-AFS)代替常用的原子吸收光谱法(AAS)测定土壤中的铅含量.结果表明,微波消解-氢化物发生-原子荧光光谱法不仅可以避免传统消解方法中费时长、污染重和消化样品中的铅易流失等缺点,而且检出限为6μg/kg,接近石墨炉原子吸收光谱法的5μg/kg,远低于火焰原子吸收光谱法.本方法的重现性好,对6种土壤样品的测定,其相对偏差(RSD)为3.4%~6.5%(n=21),回收率为88.7%~111.2%.     

微波消解-石墨炉原子吸收光谱法测定亚热带水果中铅

【目的】制备密闭微波消解样品,建立石墨炉原子吸收光谱法测定亚热带水果中铅的方法。【方法】样品经硝酸消解,所得溶液蒸发浓缩后定容至25mL,取适量用石墨炉原子吸收光谱法测定,并优化微波消解条件和仪器测定条件,对各种最佳分析条件进行探讨和验证。【结果】在最佳工艺条件下,铅的校准曲线在0~8.0μg/L范围内呈线性,方法检出限为1.247μg/L,相对标准偏差为4.7%,回收率为95.0%~102.0%。用标准物质进行对照,其测定值均在给定的标准值范围内。【结论】该方法具有操作简单、灵敏度高、回收率和重复性好等特点,适合亚热带水果中铅含量的测定。     

原子吸收及原子荧光法测定内消瘰疬丸中铅砷汞含量测定

建立测定内消瘰疬丸中铅、砷、汞残留量的。采用微波消解的方法,用石墨炉原子吸收分光光度法测定铅含量,用原子荧光法测定砷汞含量。结果:铅、砷、汞的回收率分别为103.6%、92.5%、92.3%。该方法操作简便、快捷、可用于内消瘰疬丸及类似中成药的铅、砷、汞含量测定。     

农田土壤中铅、镉含量测定方法的研究

比较微波消解和电热板消解进行样品前处理对测定农田土壤中镉、铅含量的影响。石墨炉原子吸收法结论微波消解溶样时间短,试剂用量少,空白值低,基本避免了样品污染和元素损失,是理想和成熟的样品消解方法。     

微波消解——火焰原子吸收测定化妆品中的铅、铬、铜

采用火焰原子吸收光谱测定化妆品中铅、铬、铜,并对样品前处理的微波消解条件等进行了研究。方法检测限分别5μg/L(Pb)、3μg/L(Cr)、2μg/L(Cu),加标回收率为96.67%~97.75%。     

微波消解-石墨炉原子吸收法测定大米中的痕量钒

用微波消解-石墨炉原子吸收光谱法测定大米样品中痕量钒。研究了不同微波消化体系对大米钒测定结果的影响,确定了微波消解样品和石墨炉原子吸收测定钒的最佳条件。结果表明,采用四段微波消解方式,以HNO3-HCl-H2O2(3∶1∶1)为消解液、EDTA为基体改进剂,进行钒测定可获得满意的结果。方法的检出限为0.63μg/L,线性范围0～300μg/L,相关系数R=0.997 8。该法简便快速,具有较高的灵敏度和准确度,用于大米样中钒的测定,回收率在101.2%～105.8%,标准试样结果平均相对偏差在10%以内。     

微波消解-ICP-AES法测定ABS塑料中的铅

建立微波消解-电感耦合等离子体原子发射光谱法测定ABS塑料中铅的含量为297.5 mg/kg.实验中消解体系为7.0 m L浓硝酸和1.5 m L30%过氧化氢,实验方法的检出限为7.35 mg/kg,精密度RSD5%,加标回收率为88.0%~107.0%.该方法样品用量少,溶样周期短,测试速度快,适用于ABS塑料中铅含量的快速测定.     

恒温消化原子荧光法测定面粉中的痕量铅

研究了恒温消化发生原子荧光恒温消化法测量面粉中的痕量铅含量,采用DTD-30恒温消解仪于90℃预消解35 min,180℃消化35 min除去残酸.采用AFS-230E型双道原子荧光光度计,采用氢化物-原子荧光法测定面粉中的铅含量,实验确定了最佳测定条件.该法测定面粉中铅含量的相对标准偏差RSD为1.35%(n=9),检出限为0.1 ng/mL.铅的线性范围为0～30 ng/mL,相关系数大于0.998.加标回收率为106.92% .     

原子吸收法测定三叶木通果皮中锌铅铬含量

用浓硝酸-高氯酸微波消解三叶木通果皮,用原子吸收分光光度法测定果皮中锌、铅和铬的含量.实验结果表明,锌、铅、铬3种重金属质量分数大小顺序为w（Zn）＞w（Pb）＞w（Cr）,其值分别为9.084×10^-3%,6.868×10^-3%,3.241×10^-3%,加标回收率分别为100.24%,99.87%,101.01%,相对标准偏差（RSD）分别为1.23%,1.22%,1.91%.该方法用于测定三叶木通果皮中锌铅铬含量,测定结果的准确度和回收率高,精密度和重复性好,具有良好的应用价值.     

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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