微波消解氢化物原子荧光法测定海水蔬菜中的砷、汞

建立了一种微波消解处理样品,氢化物发生原子荧光光谱法同时测定海水蔬菜中微量砷、汞的方法.在优化的实验条件下,海水蔬菜中砷、汞回收率分别为96.0%、103.2%;检出限分别为0.24μg/L和0.17μg/L.并对方法的精密度和准确度进行评估,结果表明该方法用于海水蔬菜中砷和汞的同时测定是可行的.     

优化的原子荧光法测定砷汞含量

建立了用AFS-830双道原子荧光光度计同时测定不同样品中砷和汞的氢化物发生-原子荧光法检测方法.在优化的仪器工作条件下:砷和汞的线性检测范围广,分别为0~10μg/L和0~1μg/L;方法灵敏,检出限分别为0.042μg/L和0.038μg/L;样品加标回收率高,分别为99.5%~100.1%和97.5%~99.9%,可用于工业环境监测中测定不同样品中的砷和汞的含量.     

原子荧光光谱法测定稻谷及制品中含总砷的量

应用氢化物发生原子荧光光谱法测定稻谷及其制品中总砷,采用微波消解法对稻谷及其制品样品进行总砷的前处理.结果表明,方法检出限为0.02 mg/kg,线性范围为0~25μg/L,回收率为92.6~103.0%,相对标准偏差为0.8%.所测稻谷中总砷范围在0.126~0.526 mg/kg,糙米中总砷范围在0.096~0.174 mg/kg,大米中总砷范围在0.012~0.054 mg/kg.     

微波消解-氢化发生-原子荧光光谱法测定涂料中的砷

采用微波消解-氢化发生-原子荧光光谱法连续测定涂料中的砷,用硝酸消解样品,探讨了负高压、灯电流、原子化器温度及高度、载气流量、屏蔽气流量、硼氢化钾-氢氧化钾的浓度等的选择。本方法的线性范围为0~200?g/L,相关系数r=0.9996,检出限为0.3652μg/L,相对标准偏差RSD为1.23%,回收率为98%~104%。     

微波消解-氢化物发生-原子荧光光谱法同时测定食品中的As和Hg

应用微波消解-氢化物发生-原子荧光光谱法测定食品中微量砷(As)和汞(Hg)的含量,实验结果表明,在最佳条件下,该法的回收率分别是:砷为94.5%～101%,汞为92%～96%,相对标准偏差值为1.0%～1.66%,As和Hg的检出限分别为0.1μg·L-1和0.02μg·L-1,其线性范围分别为1.0～100μg·L-1和0.2～60μg·L-1.该法能满足各类食品中微量砷和汞含量的测定要求,具有分析速度快、操作简便、检验效率高等特点.     

石墨消解-原子荧光光谱法测定植物中的砷

建立石墨消解对植物进行前处理的方法,消解液中总砷用原子荧光光谱法测定。砷的浓度在0.00~5.00μg/L范围内与荧光强度线性关系良好,相关系数：r=0.9999,方法检出限为0.002 mg/kg。使用有证标准物质进行验证,结果在一倍标准偏差以内;相对标准偏差为3.5%。对植物样品小麦进行加标回收实验,加标回收率在90.0﹪~94.8﹪之间。实验表明：用石墨消解-原子荧光光谱法测定植物中砷的方法,操作方便、消解时间短、浓缩样品提高测量的精密度和准确度、使用成本低。适合大批量样品的测定。     

微波消解火焰原子吸收法测定中草药中痕量铅、铬、镉和镍的研究

研究了用火焰原子吸收法测定中草药中痕量铅、铬、镉和镍的方法,中草药样品采用HNO3-H2O2消化体系微波消化,然后用原子吸收光谱法测定.在最佳微波消化条件和测定条件下,检出限为0.3~0.8μg/L,测定结果的相对标准偏差为1.8%~2.4%,回收率为94%~105%,结果令人满意.     

氢化物原-子-荧光光谱法测定食品中微量砷

采用氢化物原子荧光光谱法研究了用砷化钾－硫脲作为预还原剂对测定砷的影响，讨论和确定了最佳检测条件，结果表明：该方法线性范围广，线性关系良好，r=0.9998,检出限为0.219μg/L，标准偏差为0.63%-0.85%，回收率为94．22－100.60%，该方法准确，简便，可广泛用于食品中砷的检测。     

微波消解-氢化物发生原子荧光法连续测定砷、硒、锑的研究

建立了氢化物发生原子荧光法连续测定食品中砷、硒和锑的方法.采用微波消解的方法处理样品,研究了在酸性介质下,砷、硒、锑与硼氢化钾生成氢化物的反应行为,并对影响荧光强度的诸因素进行了试验和探讨.该法砷、硒、锑的线性范围分别为0~250,0~200,0~200μg/L,检出限分别为0.36,0.42,0.31μg/L,相对标准偏差为1.23%~4.85%.该法灵敏度高,检出限低,应用于实际样品的测定,结果满意.     

原子荧光光谱法测定土壤中砷

样品采用混酸(HNO3+HClO4+H2SO4)消化,控制10%盐酸介质,以抗坏血酸-硫脲还原,用原子荧光光谱法测定。加标回收率为94.2%,相对标准偏差0.65%(n=11),检出限0.08ng.mL-1,测定土壤、水系沉积物等标准物质中砷的含量,测定结果在标称值范围内。     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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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