CaCl_2-NaCl熔盐中Fe~(3+)电化学行为的循环伏安分析

利用ZrO_2(Y_2O_3)固体电解质管集成构建Pt,O_2(air)|ZrO_2作为参比电极的电化学电池,采用循环伏安法在1273、1323、1373、1393K温度下对溶解0.5%Fe2O3的CaCl2-NaCl共晶熔盐中Fe~(3+)的电化学行为进行研究,分析了Fe~(3+)在Pt电极上的还原机理,并计算了电极反应交换电子数、Fe~(3+)扩散系数与Fe~(3+)扩散活化能等电化学参数。结果表明,在实验温度范围内,熔盐中Fe~(3+)在Pt电极上还原为Fe的反应是一步还原并受扩散控制的可逆过程;随着温度升高,Fe~(3+)扩散系数增大,Fe~(3+)扩散活化能为97.91kJ·mol-1。另外,本实验测得的Fe~(3+)扩散系数与文献值基本相符,因此,可以认为利用该电化学电池装置研究溶解有Fe2O3的CaCl2-NaCl溶盐的电化学行为是可行的。     

时钟反应在离子分析中的应用

本文研究了利用时钟反应S_2O_8~(2-)+(?)(1％淀粉作指示剂)分析Fe~(3+)、Fe~(2+)离子浓度;H_2O_2+(?)(1％淀粉作指示剂)分析WO_4~(2-)、Cr_2O_7~(2-)、VO_3~-离子浓度;BrO_3~-+(?)(偶氮洋红作指示剂)分析苯酚、α-萘酚浓度,并作出这些离子的工作曲线。     

铁离子电还原过程的研究

用电位扫描法和旋转电极技术,研究了铁离子在铂电极和玻碳电极上的还原行为.结果表明该还原反应的可逆性明显地依赖于相伴阴离子的本性,在含SO_4~(2-)、NO_3~-、阴离子的溶液中,反应并非完全可逆,当溶液合Cl~-、CN~-离子时,电极反应是可逆的,而在F~-、C_2O_4~(2-)、Cit~(3-)、CNS~-、P_2O_7~(2-)等离子存在时,反应是不可逆的.实验证明,Fe~(2+)离子还原时,电极表面有吸附膜生成,此膜对H~+的放电析出有催化作用.从旋转电极实验求得1.0mol·dm~(-3)KCl溶液中,Fe~(3+)离子的扩散系数D_(Fe~(3+))=(7.9±0.1)×10~(-6)cm~2·s~(-1),标准速度常数k=(2.5±0.2)×10~(-3)cm·s~(-1).     

基于罗丹明b类的Fe~(3+)荧光探针的合成及其性能研究

以2,6-吡啶二羰酰氯与罗丹明酰胺缩合反应的产物(BR)为荧光"关—开"型探针,研究了探针BR选择性识别Fe~(3+)的各种影响因素,建立了BR荧光检测分析痕量Fe~(3+)的方法.Job's Plot实验证明BR与Fe~(3+)的络合比为1∶2.且Fe~(3+)浓度在0~20μmol/L范围内与BR呈良好的线性关系(R~2=0.998),检出限为1.8×10~(-8)mol/L.     

Cu~(2+)、Fe~(3+)、Zn~(2+)对香豆素-3-羧酸与牛血清白蛋白相互作用的影响

用荧光光谱法研究Cu~(2+)、Fe~(3+)、Zn~(2+)对香豆素-3-羧酸与牛血清白蛋白(BSA)相互作用的影响.结果表明:三种金属离子均能增强香豆素-3-羧酸对BSA的荧光猝灭及两者的结合作用,使体系的荧光猝灭常数、结合常数增大;Zn~(2+)的存在没有改变两者的作用力类型,仍以疏水作用力为主,Cu~(2+)、Fe~(3+)存在下,作用力变为以静电引力为主.表明Cu~(2+)、Fe~(3+)、Zn~(2+)对香豆素-3-羧酸与牛血清白蛋白的作用有重要影响.     

测定碘离子的高灵敏度化学发光分析法

本文提出了一种测定碘离子的化学发光分析法:以过量的 Fe~(3+)氧化Ⅰ~-,定量生成 Fe~(2+),利用 Fe~(2+)—O_2—鲁米诺化学发光体系测定生成的 Fe~(2+)以确定Ⅰ~-的含量.方法的检出限是1.8ppb Ⅰ~-,工作曲线的线性范围为1×10~(-7)～1×10~(-5)M I~-,相对标准偏差小于2%,已用于一些水样中Ⅰ~-的测定.     

用极化曲线法研究硫酸盐还原菌厌氧腐蚀

本文采用极化曲线法研究了油田水中硫酸盐还原菌(SRB)导致的钢铁厌氧腐浊以及某些因素的影响.实验中采用了含Fe~(2+)或不含Fe~(2+)以及合SO_4~(2-)或不含SO_4~(2-)的培养基.实验表明,Fe~(2+),S~(2-),FeS以及SO_4~(2-)等添加物会促进碳钢的SRB腐蚀.它们对腐蚀的主要作用是促进了腐蚀反应的阴极去极化.Fe~(2+)的显著影响还包括促进SRB的生长繁殖及磷代谢.     

柠檬酸钠-Fe2+催化纳米过氧化钙修复污染地下水

为了修复被三氯乙烯污染的地下水,利用化学沉淀法制备纳米过氧化钙,采用柠檬酸钠强化Fe~(2+)催化效果,考察柠檬酸钠与Fe~(2+)的配比,以及纳米过氧化钙、柠檬酸钠-Fe~(2+)投加量等对修复效果的影响,并分析三氯乙烯的降解路径。结果表明:在中性条件下,柠檬酸钠-Fe~(2+)可以有效催化纳米过氧化钙降解地下水中的三氯乙烯;体系中纳米过氧化钙、柠檬酸钠-Fe~(2+)的浓度以及柠檬酸钠与Fe~(2+)的配比对三氯乙烯的降解有显著影响,降解反应符合伪一级动力学模型;在三氯乙烯浓度为0.16 mmol/L,柠檬酸钠与Fe~(2+)的物质的量比为1∶1,体系中纳米过氧化钙、柠檬酸钠-Fe~(2+)的浓度分别为2.88、 0.96 mmol/L时,反应3 h后三氯乙烯去除率可达98.0%。     

Fe~(3+)掺杂TiO_2溶胶光催化降解甲基橙动力学研究

采用溶胶-凝胶法制备TiO_2溶胶和不同掺杂量Fe~(3+)/TiO_2溶胶,以甲基橙作为有机模拟污染物研究Fe~(3+)/TiO_2溶胶光催化甲基橙动力学行为和最佳降解条件.结果表明,掺杂Fe~(3+)与TiO_2的最适浓度比为Fe~(3+):TiO_2=0.1%,可将TiO_2的光催化效果提高到84.2%,影响降解因素依次为钛醇比Fe~(3+)浓度pH.光催化甲基橙降解过程符合Langmuir等温吸附方程;R~20.92的结果表明:该降解反应较符合准一级Langmuir-Hinshelwood方程.     

Fe~(3+)掺杂TiO_2溶胶光催化降解甲基橙动力学研究

采用溶胶-凝胶法制备TiO_2溶胶和不同掺杂量Fe~(3+)/TiO_2溶胶,以甲基橙作为有机模拟污染物研究Fe~(3+)/TiO_2溶胶光催化甲基橙动力学行为和最佳降解条件.结果表明,掺杂Fe~(3+)与TiO_2的最适浓度比为Fe~(3+):TiO_2=0.1%,可将TiO_2的光催化效果提高到84.2%,影响降解因素依次为钛醇比>Fe~(3+)浓度>pH.光催化甲基橙降解过程符合Langmuir等温吸附方程;R~2>0.92的结果表明:该降解反应较符合准一级Langmuir-Hinshelwood方程.     

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