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1.
稀土元素与偶氮氯膦Ⅲ在乙醇—水介质中显色反应的研究   总被引:1,自引:0,他引:1  
偶氮氯膦Ⅲ(ChlorophsphonazoⅢ)(C. P. Ⅲ)为稀土元素的显色剂之一。今村介召了稀土元素的克分子吸光系数(λ_(max)=665nm)为(2.15~4.3)×10~4l·mol~(-1)·cm~(-1)。武汉大学报告了重稀土的克分子吸光系数为(5.4~7.4)×10~4l·mol.(-1)·cm~(-1)。竹田津指出,偶氮氯膦Ⅲ与輕重稀土的显色反应有所不同,在一定条件下,重稀土的絡合物可由α型轉变成β型。我們研究了在乙醇——水介質中形成RE—C.P.Ⅲ絡合物的适宜条件,得出稀土克分子吸光系数(λ_(max)=675nm)为(1.26~1.59)×10~5l·mol~(-1)·cm~(-1),是文献值的2~3倍。  相似文献   

2.
研究了Sm(Ⅲ)-DBC·CPA-CPB-C_2H_5OH体系的光度特性和最佳显色反应条件,该体系与Sm(Ⅲ)-DBC·CPA体系相比,虽灵敏度未见明显提高,但选择性却有显著提高.Sm(Ⅲ)浓度在0~14μg/25ml范围遵循比尔定律,当λ_(max)=659nm.表观ε=7.6×10~4L·mol~(-1)cm~(-1).该方法用于矿样测定结果满意.  相似文献   

3.
分光光度法测定Fe(Ⅲ)-二甲酚橙显色反应的研究   总被引:2,自引:0,他引:2  
在 5× 10 -2 mol·L-1HCl溶液中 ,二甲酚橙与Fe(Ⅲ )生成紫红色络合物 ,其最大吸收波长位于5 6 0nm处 ,表观摩尔吸光系数ε =2 .0× 10 4L·mol-1·cm-1.Fe(Ⅲ )含量在 0~ 2 .4mg·L-1范围内符合Beer定律 .用于水样中微量铁 (Ⅲ )的测定 ,结果较满意  相似文献   

4.
本文研究了5-(4-磺基-1-荼偶氮)-8-羟基喹啉在表面活性剂 OP 存在下与钴(Ⅱ)的显色反应的条件。试验结果表明,在 pH5. 6~6. 6的 KH_2PO_4-NaOH 缓冲溶液和 OP 存在下,钴(Ⅱ)与该试剂能形成稳定的红色配合物。其λ_(max)=510nm,ε_(510) =6. 69×10~4L·mol~(-1) ·cm~(-1) ,钴(Ⅱ)∶试剂=1∶3,钴(Ⅱ)含量在0~0. 7μg/ml 范围内符合比尔定律。本文所拟定的分析方法用于维生素 B_(12) 中微量钴的测定,获得满意结果。  相似文献   

5.
本文研究了青霉素和盐酸羟胺的反应产物与铁的显色反应.在pH8.0的NH_3·H_2O-NH_4C l缓冲介质中,铁与青霉素和羟胺的反应产物生成亮黄色配合物,其配合物的最大吸收波长位于435nm处,摩尔吸光系数为3.2×10~3L·mol~(-1)·cm~(-1),Fe(Ⅲ)浓度在0-5.5μg/ml范围内符合比尔定律.该法用于碳酸钙中微量铁的测定,结果满意.  相似文献   

6.
催化动力学光度法测定痕量铁   总被引:3,自引:1,他引:2  
在硫酸介质中 ,Fe(Ⅲ )离子在活化剂邻二氮菲的存在下可催化抗坏血酸还原 (2 .6_二溴_4_硝基苯 )_3_(4_硝基苯 )三氮烯的褪色反应 ,据此提出了测定痕量铁的新方法 ,该方法的线性范围为 0~ 33μg/ 2 5mL ,检测限为 6 .9× 10 -3 μg·mL-1,将本法用于人发与自来水中铁的测定 ,结果满意 .  相似文献   

7.
本文研究了在聚乙烯醇存在下,钼(Ⅵ)—SCN—甲基紫高灵敏离子缔合体系,在0·10—0·14M硫酸介质中,该体系λ_(max)=530nm,表观摩尔吸光系数_(530)=9·20×10~5l·mol~(-1)·cm~(-1),0~μgM_0/25ml符合比尔定律,选择性较好,并用于钢铁中钼的测定。对显色反应机理作了初步探讨。  相似文献   

8.
在明胶和硫酸介质中,维多利亚兰B与十二烷基苯磺酸钠生成稳定的兰色配合物。ε595_(nm)=2.30×10~4L·mol~(-1)·cm~(-1)。基于这一反应,可以测定城市污水中阴离子表面活性剂含量。用本法进行11次实际样品的平行测定,其相对标准偏差为2.1%,标准加入法测得回收率为94.5%~99.1%。  相似文献   

9.
本文研究了9-吡啶基荧光酮与铬的反应条件,确定在pH5.0~6.0范围内形成稳定的络合物,λ_(max)=590nm,组成为Me∶R=1∶3,表观摩尔吸光系数ε=1.12×10~5L·mol~(-1)·cm~(-1)。应用拟定的方法测定了水中的铬,结果令人满意。  相似文献   

10.
在酸性介质中,钌(Ⅲ)对KIO_4氧化DBC—偶氮氯膦的褪色反应有明显的催化作用,确定了测定微量钌的催化分光光度法的最佳条件,其摩尔吸光系数ε_(550)=2.79×10~6L·mol~(-1)·cm~(-1),在0.04~0.3μg/10mL范围内符合比耳定律,应用于贵金属中钌的测定,结果满意。反应在水相中直接进行,简便快速,选择性亦好。  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.
<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   

19.
20.
<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has  相似文献   

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