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1.
在8.0×10-3mol/LHCl-2.0×10-3mol/LKI介质中,吖啶橙(AO)在515nm处有1个同步荧光峰.当有NO-2存在时,NO-2与过量的I-反应生成I-3,I-3与AO形成缔合微粒,在320,560nm处产生2个共振散射(RS)峰,在470nm处产生1个同步散射峰.NO-2浓度在0.068~7.36mg/L范围内与320nm波长处的共振散射光强度成线性关系.据此建立了一个测定水中NO-2的共振散射光谱分析法.光谱研究结果表明,(AO-I3)n缔合微粒和界面的形成是导致体系RS增强的根本原因.  相似文献   

2.
在8.0×10-3 mol/L HCl-2.0×10-3 mol/L KI介质中,吖啶橙(AO)在515 nm处有1个同步荧光峰.当有NO-2存在时,NO-2与过量的I-反应生成I-3,I-3与AO形成缔合微粒,在320,560 nm处产生2个共振散射(RS)峰,在470 nm处产生1个同步散射峰.NO-2浓度在0.068~7.36 mg/L范围内与320 nm波长处的共振散射光强度成线性关系.据此建立了一个测定水中NO-2的共振散射光谱分析法.光谱研究结果表明,(AO-I3)n缔合微粒和界面的形成是导致体系RS增强的根本原因.  相似文献   

3.
氯化银胶体在375、496和565 nm产生3个明显的共振散射峰,其中496 nm处的散射峰强度最大且最稳定,适于进行共振光散射比浊法分析.探讨了共振光散射比浊法的机理,建立了在酸性氯化钠-乙二醇溶液中,共振光散射比浊法测定银离子的新方法.线性回归方程IRLS=7.60cAg+-4.82,R=0.999 8;检出限0.04μg/mL.此方法用于实际样品测定,取得了满意效果.  相似文献   

4.
亚硝酸根的催化动力学光度法测定   总被引:2,自引:0,他引:2  
在酸性介质中,NO-2对KBrO3氧化甲基红反应有强烈的催化作用,研究了反应的动力学条件,建立了测定痕量NO-2的新方法,方法的测定范围为0.32~4.8μg/L,检出限为5.4×10-11g/L.该方法简便、灵敏,选择性好,用于水样中NO-2的测定,结果满意.  相似文献   

5.
共振光散射法测定环境水样中镉的研究及应用   总被引:5,自引:1,他引:4  
在体积分数1%的OP介质中,Cd2 与S2-反应形成憎液溶胶体系,可使体系共振散射光强度增强.通过实验确定了适宜的反应条件及共振光散射强度与镉浓度之间的关系.在λ=476nm处,共振光散射强度最大,并且共振光散射强度与镉浓度成良好的线性关系,线性范围为0.0~20.0μg/mL,相关系数r=0.9995,检出限为6.33×10-3μg/mL,RSD为1.19%~1.42%,样品加标回收率为98.80%~102.30%.该方法简便、快速,用于实际样品中镉的含量测定,其精密度和灵敏度均优于紫外可见分光光度法,测量结果与原子吸收法相比较,令人满意.  相似文献   

6.
在弱酸性条件下,核固红,Cu(Ⅱ)与盐酸吡硫醇共存时,导致体系共振光散射强度明显增强.据此建立了测定盐酸吡硫醇的共振光散射分析法.在最佳条件下,Cu(Ⅱ)-核固红-盐酸吡硫醇体系的最大散射峰位于364nm处.共振光散射增强的程度与盐酸吡硫醇的浓度在0.5~11.5μg.mL-1之间呈良好的线性关系.方法的检出限为1.5×10-2μg.mL-1.将方法用于片剂中盐酸吡硫醇的测定,并与药典法进行对照,经t检验证明2种方法无显著性差异.  相似文献   

7.
探讨了微乳液的增稳作用及对汞-四硫氰基二氨合铬酸铵乳浊体系的共振光散射(RLS)光谱,该体系的RLS光谱强度与浓度成正比.在最佳的测定条件下,线性范围为0-20.5μg/ml,相关系数r=0.9996,检出限为0.028μg/ml.用此法测定了水产品中的汞,加标回收率为96.0%-103%.  相似文献   

8.
建立了一种快速、准确测定水中镉含量的共振光散射(RLS)方法。在pH=9.0的氨-氯化铵缓冲介质及表面活性剂十二烷基硫酸钠(SDS)存在下,镉(II)与2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚(5-Br-PADAP)可形成复合物,导致体系共振光散射强度显著增加,据此建立了利用共振光散射技术测定镉含量的分析方法。在优化条件下,依次加入0.40 mL的pH=9.0的NH_3-NH_4Cl缓冲溶液,0.10 mL的1.0 mmol/L 5-Br-PADAP溶液,适量镉(II)标准使用液,以及0.40 mL的1.0 mmol/L SDS水溶液,并定容至10.0 mL,于室温下反应10 min,在最大散射峰604 nm处测定共振光的散射信号。结果表明,共振光散射强度与镉(II)质量浓度在5.3~200.0μg/L范围内呈线性关系,检出限(3S_d/K)为0.1μg/L。  相似文献   

9.
在pH4.41 Britton-Robinson缓冲介质中,白蛋白(BSA)与二碘荧光黄(DIIF)作用形成复合物,使最大波长377 nm的共振光散射光谱得到加强,根据其共振光散射的增强效应,可用于蛋白质的定量测定.研究了复合物反应的适宜条件,结果表明:在优化的条件下,蛋白质浓度在0.0-5.0μg/mL范围内与共振光散射强度呈良好的线性关系,方法的检出限为0.027μg/mL.用于合成样品中蛋白质的测定,获得满意结果.  相似文献   

10.
共振光散射法测定镉的应用研究   总被引:4,自引:3,他引:1  
在十二烷基硫酸钠(SLS)存在的条件下,基于KI和Cd(II)形成[CdI4]2-络阴离子后与四丙基溴化铵(TPAB)结合形成离子缔合物使共振光散射(RLS)信号强度明显增强,建立了运用共振光散射技术测定水样中镉含量的新方法.研究了四丙基溴化铵-碘化钾-镉体系的共振光谱特征,在364 nm处体系的散射光强度最大.在最佳实验条件下,体系的共振光散射强度与Cd(II)浓度在0.08~4.0μg.mL-1范围内呈良好的线性关系,检出限可达2.80ng.mL-1.用此方法测定合成水样中的Cd(II),操作简便快速,回收率在96.4%~105.7%之间,结果令人满意.  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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