流动注射化学发光测定洗衣粉中的磷含量

在碱性介质中,Cu2+对鲁米诺-盐酸羟胺的化学发光有明显的增敏作用,而PO3-4能与Cu2+反应生成Cu3(PO4)2沉淀,对Cu2+增敏的鲁米诺-盐酸羟胺的化学发光有抑制作用,据此建立测定洗衣粉中PO3-4的流动注射化学发光分析方法.在1.0×10-10～1.0×10-7 mol·L-1范围内,洗衣粉中PO3-4的浓度与相对发光强度有良好的线性关系,线性方程为△I=214.6 +214.6c,线性相关系数为0.999 3,检出限为1.0×10-12mol·L-1.对1.0×10-7mol·L-1的PO3-4进行11次平行测定,其相对标准偏差为1.3;.此方法用于测定洗衣粉中磷的含量,结果令人满意.     

钴膜修饰碳纤维离子选择性微电极测定H2PO4-

以钴膜修饰碳纤维微电极为离子选择性电极建立了一种测定磷酸盐的新方法.利用该选择性微电极探讨测定磷酸盐的条件,并测定该电极的性能参数,在1.0×10-6～1.0×10-3mol·L-1范围,磷酸盐溶液浓度的对数与电位呈良好的线性关系和能斯特响应,检出限为6.0×10-7mol·L-1,并且该电极有良好的重现性、稳定性和选择性.     

反式双氨基四苯基卟啉修饰电极用于汞离子的测定

采用滴涂法制备了反式双氨基四苯基卟啉修饰电极(trans-d-A-TPP/GCE),并用原子力显微镜(atomic force microscopy)对其进行了表征,用循环伏安法研究了该修饰电极的电化学性质.建立了一种识别汞离子的溶出伏安分析方法,在0.2 mol·L-1NaAc-HAc(pH 3.6)支持介质中,在-0.5 V电位下富集200 s,汞离子响应的线性范围为1.0×10-8mol·L-1～1.0×10-6mol·L-1,检出限1.0×10-9mol·L-1.对实际水样进行了测定,结果满意.     

钙-茜素S络合物体系在汞膜电极上的电化学行为及其应用

在0.1 mol KOH介质中,用微分脉冲伏安法在汞膜玻碳电极上得到钙-茜素S络合吸附波,峰电位为-1.17V(vs.Ag-AgCl),峰电流与钙的浓度在5×10-8～4.2×10-5mol·L-1范围内呈良好的线性关系,检测限为2×10-8 mol·L-1.此络合波应用于血清中微量钙的测定,得到满意的结果.实验表明,该波为1:2的钙-茜素S的络合吸附波,还原过程为伴随两电子参与的不可逆电极反应.     

线性扫描极谱法连续测定红菇中的铜、镉、锌

在0.4mol·L-1 NH3·H2O-NH4Cl缓冲溶液中(pH=9.19),用线性扫描极谱法连续测定了红菇中Cu、Cd、Zn三种微量元素的含量.研究结果表明:Cu2 、Cd2 、Zn2 的峰电位分别为-0.45V(vs·SCE)、-0.79V(vs·SCE)、-1.33V(vs·SCE);线性范围分别为1.3×10-5～1.5×10-4 mol·L-1、2.5×10-5～5.0×10-4mol·L-1、2.5×10-5～5.0×10-4mol·L-1;检出限分别为0.006μg/mL、0.005μg/mL、0.006μg/mL,回收率分别为97.0～100.5%、98.4～102.0%、96.5～102.6%.此方法准确、简便、快速、灵敏度高.     

巯基乙酸修饰电极选择性测定对苯二酚

通过自组装得方法制备了巯基乙酸修饰的金电极.在0.10 mol·L-1的磷酸盐缓冲溶液中(pH=7.0),用循环伏安法和示差脉冲伏安法研究了对苯二酚在修饰电极上的电化学行为,在相对低的电位条件下,对苯二酚显示一对氧化还原峰.在1.0×10-6mol·L-1到3.0×10-3mol·L-1浓度范围内,氧化峰电流与对苯二酚的浓度成线性关系,相关系数是0.998,检测限为4.0×10-7mol·L-1.该修饰电极在间苯二酚存在的条件下,能被用于选择性检测对苯二酚,得到了令人满意的结果.     

羧基化的 MWNTs/Nafion/SiC 修饰电极对痕量铅离子的测定

采用羧基化的多璧碳纳米管(MWNTs)、Nafion及SiC对玻碳电极进行修饰,表面修饰效果采用电子显微镜进行表征,对测定条件进行了优化.并用修饰后的电极对实际水样中的铅离子进行差分脉冲阳极溶出伏安法测定.结果表明,在2.0×10-8~1.2×10-6 mol·L-1范围内,峰电流与铅离子浓度成正比.线性方程为ip=3.0186×107C+8.6165(ip的单位为μA;C的单位为mol·L-1), R =0.9916,最低检测限为3.0×10-9 mol·L-1(S/N=3).同时考察了各种干扰离子及表面活性剂的影响,结果表示此电极测定铅离子效果较好,适用于对铅离子的测定     

碳纳米管修饰碳糊电极同时测定铜和铅

制备了碳纳米管化学修饰碳糊电极,采用循环伏安法,在pH为4·20的B-R缓冲溶液中同时对Cu2+和Pb2+进行测定.结果表明,Cu2+和Pb2+浓度分别在3·0×10-6～1·0×10-4mol/L和6·0×10-6～1·0×10-4mol/L范围内呈良好的线性关系,检出限分别为5·6×10-8mol/L和1·8×10-7mol/L,线性相关系数R分别为0·9884和0·9909.     

电化学方法制备石墨烯修饰电极在亚硝酸根检测中的应用

采用循环伏安法直接制备了石墨烯修饰玻碳电极并对其进行了表征,研究了亚硝酸根在石墨烯修饰玻碳电极上的电化学行为.研究结果表明:石墨烯修饰电极对亚硝酸根的氧化有良好的电催化活性,在0.10 mol·L-1PBS缓冲液(pH值为7.0)中动态安培法检测亚硝酸根的线性范围为2.69×10-6～8.13×10-4 mol·L-1和8.13×10-4～8.56×10-3 mol·L-1,灵敏度分别为42.68和10.91 μA·(mmol·L-1)-1,检出限为8.68×10-7mol·L-1(3sb).利用该方法测定了土壤样中亚硝酸根的含量,结果令人满意.     

电化学法直接测定游离硫离子

用电化学方法在pH=13、15～18℃环境中直接测定游离S2-,灵敏、简便.实验以单线性伏安法,采用铂盘电极对S2-进行测试,结果显示,线性范围为1.00×10-5～5.00×10-4mol·L-1,检测限在1.00×10-5mol·L-1,回收率92.03%.对五个天然水体样品进行测定,其中一个样品中的S2-浓度是2.00×10-5mol·L-1,     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Design and analysis of generic LBS application developing platform

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.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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