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1.
用双硫腙显色分光光度法测定铁矿石中痕量铅,该方法具有简单、快速、灵敏等特点,用以测定铁矿石中的痕量铅,获得了满意的结果.检出限为0.06μg/mL,线性范围为0.00μg/mL~1.0μg/mL Pb2+,相关系数为0.9996,回收率89%~99%.  相似文献   

2.
基于盐酸介质中,痕量间苯二酚能灵敏地催化溴酸钾氧化硫堇褪色的反应,建立了一种测定痕量间苯二酚的新方法.考察了反应的影响因素,研究了该催化反应的最佳条件及动力学参数.该法线性范围为0.02~0.30μg/10 mL,检测限为4.53×1-0 10g/mL.可用于水样中间苯二酚的测定.  相似文献   

3.
研究了在硫酸介质中 ,痕量金 (Ⅲ )催化溴酸钾氧化铍试剂Ⅱ褪色的指示反应及其动力学条件 ,据此建立一种新方法 ,该方法的检测极限为 1.2 4× 10 -11g/mL ,线性范围为0~ 0 .4μg/ 2 5mL ,用于样品的测定获得满意的结果  相似文献   

4.
在硫酸介质中,痕量甲醛对氧酸钾氧化甲基橙的反应具有催化作用,据此建立了一种简单快速的测定肉类食品中痕量甲醛的催化动力学方法.该方法对肉类食品中甲醛的线性检测范围为0.2~8.0μg/mL,检出限0.017 μg/mL,与乙酰丙酮分光光度法进行对照,该方法的测定结果可满足微量分析的要求.  相似文献   

5.
研究了在硫酸介质中痕量铜(Ⅱ)催化过氧化氢氧化乙基紫褪色反应的最佳条件,建立了高灵敏度测定痕量铜的新方法.检出限为6.0×10-10g/mL,线性范围为0.05~3.0μg/(25 mL).使用的仪器设备简单,检测简便、快速.应用于农产品中痕量铜的测定,结果令人满意.  相似文献   

6.
赵伟涛  陈燕清  黄广  闫玉新  郑平 《江西科学》2013,31(2):176-178,231
在硫酸介质中,基于痕量对苯二胺对类Fenton试剂氧化罗丹明B褪色反应有强烈的催化作用,据此建立了一种动力学光度法测定痕量对苯二胺新方法。考察了各种因素对测定方法灵敏度的影响。在最佳实验条件下,方法的线性范围为0.16~0.56μg/mL,检出限为0.03μg/mL。该方法用于环境水样中对苯二胺的测定,结果满意。  相似文献   

7.
利用DNA对帕珠沙星的荧光猝灭作用建立DNA定量测定的新方法,CT-DNA,smDNA和hsDNA响应线性范围分别为0.65~33.3μg/mL、0.78~46.3μg/mL和1.07~48.1μg/mL,检测限分别为0.07μg/mL、0.02μg/mL和0.02μg/mL。  相似文献   

8.
研究了痕量钒(V)阻抑溴酸钾氧化二甲基黄的褪色反应, 确定了最佳反应条件, 建立了一种光度测定痕量钒(V)的新方法.结果表明, 方法的检出限为2.3×10-10g/mL, 线性范围为0.40-4.0μg/L.用于化学试剂中痕量钒(V)的测定,结果满意.  相似文献   

9.
甲醛与1,3-环己二酮-组胺在弱酸性缓冲介质中反应生成强荧光化合物,由此建立一种测定食品中痕量甲醛的荧光分光光度法.在优化的实验条件下,反应体系的相对荧光强度与甲醛浓度呈良好的线性关系,该方法的线性范围为0.02~1.00μg/mL,检出限为1.8×10-3μg/mL,对0.75μg/mL甲醛平行测定11次,其相对标准...  相似文献   

10.
溴酸钾氧化甲基绿催化光度法测定痕量铜   总被引:1,自引:0,他引:1  
基于磷酸介质中,Vc存在下,痕量铜能灵敏地催化溴酸钾氧化甲基绿褪色的反应,建立了一种测定痕量铜的新方法.考察了反应的影响因素,研究了该催化反应的最佳条件及动力学参数,探讨了反应机理,该法线性范围为O.018-O.200μg/10mL,检测限为2.59×10-10g/mL.该法可用于水样和人发中铜的测定,所得结果与AAS法一致.  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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  相似文献   

19.
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  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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