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1.
研究了在H2 SO4 介质中 ,Fe(Ⅲ )对H2 O2 氧化结晶紫褪色反应的催化作用及最佳实验条件和动力学参数 ,建立了测定痕量铁的新方法 .方法的检出限为 2 73× 10 -11g/L ,测定范围 0~ 2 5 μg/L ,用于各种水中微量铁的测定 ,获得满意结果  相似文献   

2.
研究了在稀H2SO4介质中,铁(Ⅲ)催化H2O2氧化亚甲基蓝的褪色反应,建立了催化动力学光度法测定痕量铁的新方法.其检出限为3.2×10-4μg·ml-1,在0.010~0.500μg/25ml范围内,铁(Ⅲ)与lgA0/A呈良好的线性关系.该方法指示反应灵敏度高,选择性好,用于食品中铁的测定,获得满意结果.  相似文献   

3.
催化动力学光度法测定微量铜——Cu(Ⅱ)-甲基橙-H_2O_2体系   总被引:1,自引:0,他引:1  
研究了在弱酸性介质中微量铜催化 H2 O2 氧化甲基橙褪色的指示反应 ,探索了催化动力学测定铜 ( )的新方法 .该方法测定的线性范围 0 .0 5~ 3.5 μg/ 2 5 m L,本法已用于人发样及水样中的痕量铜的测定 .  相似文献   

4.
催化动力学光度法测定痕量铁及反应机理的研究   总被引:2,自引:0,他引:2  
本文研究了在弱酸介质中,铁催化过氧化氢还原次甲基蓝使其褪色这一指示反应及其动力学条件,并测定了反应的动力学参数,探讨了反应机理,据此建立了高灵敏地测量痕量铁的新方法,该方法线性范围为0~20μg/L,检出限为3.4×10-6g/L.本方法简便,分析费用低,可直接用于环境水样中痕量铁的测定.  相似文献   

5.
唐宁莉  杨长发 《广西科学》2002,9(4):268-269
研究在氢氧化钠介质中 ,痕量锇 ( )催化高碘酸钾氧化 5 - Br- PADAP的褪色反应及其动力学条件 ,建立了测定痕量锇的新方法。在选定的最佳条件下 ,方法的灵敏度为 2 .18× 10 - 1 0 g/ m l,测定范围为 10~ 6 0 mg/ L,表观活化能为 4 5 .4 KJ/ m ol。本法用于合成矿样中锇的测定 ,结果满意  相似文献   

6.
本法基于钴 ( )对高碘酸钾氧化孔雀绿有催化作用 ,提出一种灵敏地测定痕量钴 ( )的新方法。该方法线性范围在 0~ 0 .0 32μg/m L ,检测限为 2 .1× 10 - 10 g/m L。测定出反应表现活化能 Ea=37.94K J/m ol。此法用于茶叶、维生素 B12 中钴的测定 ,结果满意  相似文献   

7.
催化过氧化氢氧化钙黄绿素褪色光度法测定痕量铁   总被引:1,自引:0,他引:1  
基于Fe(Ⅲ)对过氧化氢氧化钙黄绿素的催化反应,建立了高灵敏测定痕量铁的新方法.本法线性测定范围为0.4~4ìg/L,检出限为1.4х10-10g/mL,线性回归方程为ΔA=-0.0033 0.03812CFe3 (ìg/L),相关系数r=0.9991.本法已用于人发、茶叶中铁含量的测定,结果满意.  相似文献   

8.
基于稀H3PO4介质中NO2-催化KBrO3氧化溴甲酚绿的褪色反应,建立了测定NO2-的催化光度法,该方法测定NO2-的线性范围为0.02~0.25mg/L,检出限为1.1×10-5g/L,此方法简便,灵敏度高,选择性好,用于痕量NO2-的测定,结果满意.  相似文献   

9.
本文研究了在弱酸介质中,铁催化过氧化氢还原次甲基蓝使其褪色这一指示反应及其动力学条件,并测定了反应的动力学参数,探讨了反应机理,据此建立了高灵敏地测量痕量铁的新方法,该方法线性范围为0~20μg/L,检出限为3.4×10~(-6)g/L。本方法简便,分析费用低,可直接用于环境水样中痕量铁的测定。  相似文献   

10.
本文研究了在NH3·H2O-NH4Cl介质中锰催化过氧化氢氧化苋菜红的褪色反应及其动力学条件,建立了测定痕量锰的新方法.该方法的检出限为5.6×10-4μg/mLMn,线性范围为0~1.8μg/25mL Mn,用于测定井水中痕量Mn,获得满意结果.  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.
<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   

20.
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