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1.
Cu2+对鲁米诺-铁氰化钾碱性体系的化学发光具有较强的增敏作用,据此建立了流动注射化学发光法检测Cu2+的新方法.该方法具有简单、快速、线性范围宽等优点.测定Cu2+的检出限为8.0 10-10mol/L,线性范围为1.0 10-9~1.0 10-4mol/L,测定1.0 10-5mol/L Cu2+的相对标准偏差为1.2%(n=8).  相似文献   

2.
以六氨合钴(Ⅲ)为探针的DNA共振光散射分析   总被引:1,自引:1,他引:0  
在pH为1.81~4.1的Britton-Robinson(BR)缓冲溶液中,[Co(NH3)6]3+与脱氧核糖核酸(DNA)相互作用并使其共振光散射强烈的增强.在342.0 nm处增强的共振光散射(RLS)强度与DNA的质量浓度在0.01~7.0 mg/L范围内呈良好的线性关系.据此建立了操作简便、灵敏度高的测定痕量DNA的新方法.该方法用于检测小牛胸腺DNA,检出限达到1.6μg/L级.  相似文献   

3.
用共振光散射光谱法测定痕量阳离子表面活性剂的研究   总被引:2,自引:1,他引:1  
在pH值2.0的B-R缓冲液中,痕量的溴化十六烷基三甲基胺(CTMAB)的加入导致K2HgI4共振光散射强度增加,在λex=λem=422 nm处,得到一个共振散射峰,其强度与CTMAB的浓度成线性关系,据此建立了一种测定水中阳离子表面活性剂的共振光散射光谱法.方法的线性范围为0.02-6.50 mg/L,检出限为0.15 μg/L.该方法简便快速,灵敏度高,对实际样品进行了测定,得到了满意的结果.  相似文献   

4.
在盐酸介质中,维生素C还原Se(Ⅵ)生成较稳定的硒纳米微粒.它在可见光范围内无明显特征吸收峰,在340,470,470和520 nm处产生4个共振散射峰.维生素C浓度在0.05~4.0 mg/L范围内与I340nm呈良好的线性关系.据此本文建立了一个检出限为0.01 mg/L维生素C的共振散射光谱新方法,并用于合成样品和药品中Vc含量的分析,结果满意.  相似文献   

5.
锑磷钼蓝-纳米金共振散射光谱法测定抗坏血酸   总被引:2,自引:0,他引:2  
在硫酸介质中,纳米金在774 nm处产生一个较强的共振散射峰;磷钼酸与酒石酸锑钾形成的三元杂多酸可被抗坏血酸还原形成锑磷钼蓝,导致774 nm处共振散射峰的强度降低.抗坏血酸在0.10~16.0 mg/L与共振光散射强度降低值△I呈良好的线性关系,其回归方程为△I=21.1C-2.0(C的单位为mg/L),相关系数为r=0.9981,方法的检出限为0.05 mg/L.本法用于药品、注射液、饮料中抗坏血酸的测定,具有操作简便、快速、稳定等特点,相对标准偏差为1.78%~4.62%.  相似文献   

6.
研究了脱氧核糖核酸(DNA)与阴离子染料固黄O(FYO)及阳离子表面活性剂溴化十六烷基三甲铵(CTMAB)三元体系的共振光散射光谱的特征.考察了各种影响因素,在优化条件下确立了共振光散射强度与鱼精DNA和小牛胸腺DNA以及变性后的鱼精DNA和小牛胸腺DNA浓度之间的关系,相应的线性范围分别为0.026~7.00 mg/L;0.025~7.00 mg/L;0.032~6.00 mg/L;0.031~8.00 mg/L,相关系数为0.999 1;0.999 6;0.998 1;0.999 6,检出限分为7.0,6.0,11.0,12.5 μg/L,基于共振光散射的增强,建立了一种测定DNA的新方法.图6,表4,参8.  相似文献   

7.
在pH10.23的Tris-HCl缓冲溶液中,阴离子主体小分子对羟基萘酚兰二钠盐(HNB)对阳离子表面活性剂十六烷基三甲基溴化铵(CTMAB)与脱氧核糖核酸(DNA:fsDNA、ctDNA)的共振光散射光谱有协同增强作用.考察了共振光散射(RLS)光谱的影响因素,在优化条件下共振光散射强度增加值(ΔI)与DNA浓度之间呈良好的关系,据此建立了一种测定DNA的新方法,该方法具有反应速度快(只须1min)、稳定性好、灵敏度高等特点.对于fsDNA、ctDNA的线性范围分别为0.05~2.5 mg/L,0.04~2.0 mg/L,检出限分别为25.9 ng/mL,24.9 ng/mL.用于fsDNA合成样测定效果较好.  相似文献   

8.
四磺基铜酞菁共振光散射法测定人血清白蛋白   总被引:3,自引:1,他引:3  
研究了四磺基铜酞菁与人血清白蛋白作用的共振光散射光谱,pH=1.0~3.0的范围内,人血清白蛋白的加入导致四磺基铜酞菁共振散射的增强,在407nm处存在一共振光散射强峰,其强度增加值与人血清白蛋白的浓度呈线性关系,据此建立了一种用共振光散射光谱测定人血清白蛋白的方法,该方法的线性范围为0~17mg/L,检出限为0.050mg/L(n=6,RSD为1.8%)。  相似文献   

9.
四磺基金属酞菁类染料共振光散射法测定人血清白蛋白   总被引:4,自引:1,他引:4  
在pH为2.0的Clark-Lubs缓冲溶液条件下,人血清白蛋白与四磺基金属酞菁类染料结合,使共振光散射急剧增强,并产生新的共振光散射光谱.不同体系在质量浓度0~3.0 mg/L范围内,共振光增强,与人血清白蛋白浓度呈线性关系,检出限为0.033~0.100 mg/L.表明四磺基金属酞菁类染料都可以作为共振光散射试剂测定人血清白蛋白.考察了某些共存物质的影响,初步讨论了反应机理.  相似文献   

10.
依据文献合成了巯基丙酸修饰的银纳米粒子,并用共振光散射法调查了它们与稀土离子的相互作用.在pH 7.5的Tris-HCl缓冲介质中,银纳米粒子在467 nm呈现一弱的共振光散射峰.Eu3+离子的加入导致体系共振光散射峰显著增强,并伴随47 nm(从467到514 nm)的散射峰红移.上述光谱变化可能是由于Eu3+离子与纳米粒子表面的羧基发生配位作用所导致的粒子间的聚集引起的.根据体系对其它稀土离子类似的信号响应,我们建立了一种测定稀土离子总量的共振光散射新方法.最佳条件下,稀土离子浓度在6.0×10-7-8.0×10-6mol/L范围内与共振光散射强度呈正比,检测限为2.8×10-8mol/L.该方法简便、灵敏,用于环境水样中稀土离子总量的测定,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.
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   

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