首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 257 毫秒
1.
以黑茶为底物,研究了黑茶-Br O3--Mn2+-H+-丙酮组成的振荡反应体系在恒温条件下进行的振荡反应.探讨了温度、黑茶浓度、碘酸钾干扰物对振荡反应的扰动,建立了利用此振荡体系检测加碘黑茶中碘酸根离子的方法.结果表明:反应体系有典型的振荡波形;诱导期的表观活化能为76.54 k J/mol;IO3-浓度与振荡诱导期tin有良好的线性关系,线性范围为(8.3×10-5-1.2×10-3)mol/L,线性关系回归方程为tin=4.2×102-2.5×105[IO3-],相关系数为0.995,检出限为2.8×10-5 mol/L.为加碘黑茶中碘含量的测定提供了一种新方法.  相似文献   

2.
研究了邻苯二酚(CAT)和对苯二酚(HQ)在Nafion修饰电极上的选择性测定.方波伏安法研究结果表明:在PBS水溶液的CAT和HQ共存体系中,CAT和HQ氧化峰电位分离约400 mV,而且氧化峰电流增大,以此建立了CAT和HQ的电化学选择性测定方法.在1.0×10-4mol/L CAT共存体系中HQ氧化峰电流与其浓度在5.0×10-6~6.0×10-3mol/L内呈良好的线性关系,在1.0×10-4mol/LHQ共存体系中CAT氧化峰电流与其浓度在8.0×10-6~1.0×10-3mol/L内呈良好的线性关系,结果令人满意.  相似文献   

3.
在连续搅拌反应器(CSTR)中,研究了牛磺酸对封闭体系中的B-Z振荡体系的影响.结果表明:牛磺酸的浓度在4×10-6-4×10-1 mol/L范围内振幅变化值(ΔE)与牛磺酸浓度(c)的关系符合方程:ΔE=14.062c0.126,R2=0.990 1,最低检测限达10-6 mol/L.  相似文献   

4.
在Cu(Ⅱ)存在下,研究了luminol-Cu(Ⅱ)-盐酸二甲双胍化学发光体系,建立了测定盐酸二甲双胍的流动注射化学发光新方法.结果表明,在优化的实验条件下,化学发光强度与盐酸二甲双胍浓度在1.0×10-9~1.0×10-7g/mL范围内呈线性关系.该方法测定盐酸二甲双胍的检出限为5×10-10g/mL,相对标准偏差为1.1%(1.0×10-8g/mL盐酸二甲双胍溶液,n=11).该方法已用于片剂中盐酸二甲双胍含量的测定.  相似文献   

5.
提出了Ru(phen)32+-SO32+-Ce(Ⅳ)体系化学发光法测定溶液中亚硫酸盐的方法.SO32-浓度与化学发光强度在1.0×10-7~1.0×10-4mol/L范围内成正比,检出限为1.97×10-7mol/L(S/N=3),1.0×10-4mol/LSO32溶液重复6次测定结果的相对标准偏差为4.9%.该方法用于测定白葡萄酒中亚硫酸盐总含量为4.006×10-5mol/L,加标回收结果令人满意.  相似文献   

6.
基于在碱性介质中,苯甲酸对ZnSe QDs增敏后的碱性鲁米诺-KIO_4体系的化学发光有抑制作用,建立流动注射化学发光分析方法测定苯甲酸的含量.在最优条件下,体系化学发光强度的猝灭值与苯甲酸的质量浓度在1.0×10~(-7)~1.0×10~(-5) g/mL内呈良好的线性关系,检出限为5.7×10~(-8) g/mL(3σ).对1.0×10~(-6) g/mL的苯甲酸标准溶液平行测定10次,相对标准偏差为1.02%(n=10).该方法用于水样中苯甲酸的检测,加标回收率为92.7%~107.1%.讨论体系的化学发光机理.  相似文献   

7.
用葡萄糖-丙酮-MnSO4-KBrO3-H2SO4,双有机底物化学振荡体系测定了L-蛋氨酸和D-蛋氨酸.结果表明,当L-蛋氨酸浓度为7.5×10-7~1.0×10-5mol·L-1,D-蛋氨酸浓度为4.0×10-6~2.3×10-5mol·L-1时,体系周期的变化量与所加入蛋氨酸浓度的负对数呈良好的线性关系.同时讨论了温度与反应底物对测定的影响,并用本法成功地测定了血液及饲料中的蛋氨酸,回收率为98.1%~101.1%.  相似文献   

8.
研究了在碱性条件下,维生素K3(以下简称VitK3)对Cu2 催化H2O2和NaSCN的化学振荡反应(以下简称铜体系)的影响.结果表明,VitK3的加入会使振荡图形的周期和振幅均增大,且VitK3浓度与加入VitK3后第一周期的改变值(ΔT1)呈良好的线性关系.线性范围分别为5 26×10-7~2 17×10-4mol/L和3 21×10-4~8 87×10-3mol/L,相关系数分别为0 9981和0 9975.初步探讨了VitK3对铜体系振荡反应影响的机理.  相似文献   

9.
流动注射化学发光法测定氨基乙酸的研究   总被引:2,自引:0,他引:2  
实验研究了影响化学发光信号强度值的各种因素,初步探讨了体系产生化学发光的可能机理。在优化的实验条件下,氨基乙酸在1.0×10-7~1.0×10-4kg.L-1的质量浓度范围内与化学发光信号强度呈良好的线性关系,检出限(3σ)为3×10-8kg.L-1。对质量浓度为1.0×10-6kg.L-1的氨基乙酸溶液连续测定11次,相对标准偏差(RSD)为2.8%,将该方法用于氨基乙酸模拟样品的分析,结果满意。  相似文献   

10.
利用不同浓度的酪氨酸对溴酸钠-苹果酸-[CuL](ClO4)2-硫酸化学振荡反应体系的扰动,得到一种新的定量分析测定酪氨酸的方法,其中[CuL](ClO4)2的L为5,7,7,12,14,14-六甲基-1,4,8,11-四氮杂环十四-4,11-二烯.研究结果表明,当不同浓度的酪氨酸加入到振荡反应体系时,振荡振幅的改变值ΔAm与酪氨酸浓度的对数值lg{[Tyr]0}之间呈良好的线性关系,线性范围为1.235×10-6~2.677×10-4mol/L,相关系数r=0.99918;振荡周期的改变值ΔT与酪氨酸浓度的对数值lg{[Tyr]0}呈良好的线性关系,线性范围为7.444×10-7~4.534×10-4mol/L,相关系数r=0.99361.此外还研究了反应温度、搅拌速度和组成浓度对该振荡反应的影响,同时初步探讨了酪氨酸扰动化学振荡的机理.  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.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
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   

19.
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   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号