金纳米粒子修饰石墨电极上鲁米诺-过氧化氢体系电化学发光行为的研究

研究了磷酸盐缓冲溶液(pH=7.4)中金纳米粒子修饰石墨电极上鲁米诺-过氧化氢体系的电化学发光行为。实验结果表明在金纳米粒子修饰石墨电极上鲁米诺-过氧化氢的电化学发光强度增强近10倍,初步探讨了在金纳米粒子修饰石墨电极上鲁米诺-过氧化氢体系的电化学发光增强机理。在优化的实验条件下,鲁米诺浓度在4.0×10-12～1.0×1010-mol/L之间与电化学发光强度成良好的线性关系,方法的检出限为2×10-12mol/L,对5.0×10-11mol/L鲁米诺进行11次平行测定,相对标准偏差为5.3%。     

鲁米诺-碳糊电化学发光传感器的制备与应用

利用鲁米诺作为发光试剂,制备了价廉且可重复使用的鲁米诺-碳糊电化学发光传感器。研究了鲁米诺-碳糊电化学发光传感器在过氧化氢溶液中的电化学发光特性;考察了鲁米诺-碳糊电化学发光传感器在3.0×10-8mol/L过氧化氢中的重现性及传感器寿命。结果表明电化学发光信号与过氧化氢浓度在1.0×10-13～1.0×10-11mol/L范围内呈线性关系。鲁米诺-碳糊电化学发光传感器具有制备方法简单,成本低廉,对H2O2的检测灵敏度高、响应范围宽、分析速度快等优点,有一定的应用价值。     

纳米金修饰电极和探针载体的DNA电化学发光分析方法研究

提出以纳米金修饰电极和以纳米金粒子作DNA探针载体的电化学发光检测DNA新方法.首先将纳米金自组装在金电极上,再将含巯基的目标ss-DNA固定于纳米金修饰的电极上,然后与以纳米金粒子作载体的电化学发光DNA探针进行杂交反应,将此电极做工作电极,在含有三丙胺的溶液中进行电化学发光测量.在选定实验条件下,检测囊肿纤维DNA片断(20 base)的线性范围为1.0×10-12~1.0×10-9mol/L,相关系数为0.9954,检出限为5.0×10-13mol/L.实验结果表明,纳米金具有较大的比表面积,可增强DNA在电极上的固定量,从而增强电化学发光检测信号,提高方法的灵敏度.     

电还原鲁米诺电化学发光法测定过氧化氢

研究了碳糊电极上电还原鲁米诺电化学发光反应.结果发现,鲁米诺在碳糊电极上的弱电化学还原电化学发光信号可被过氧化氢所增敏.据此,建立了一种新的过氧化氢的电化学发光分析方法.在实验条件下,相对电化学发光强度和过氧化氢的浓度在1.0×10-5～6.0×10-4mol/L范围内呈线性关系,检出限为7.3×10-6mol/L,相关系数为0.991 7.所拟方法已应用于医用过氧化氢消毒液样品中H2O2含量的测定.     

中性介质中鲁米诺电化学发光监测氧还原过程研究

利用硼酸中性缓冲溶液介质中鲁米诺在正矩形脉冲电压激励下的电化学发光行为,研究了溶解氧和H2O2对鲁米诺电化学发光的增强作用。溶解氧在0～16mg/L范围内线性增强鲁米诺的电化学发光,H2O2在5.4×10-8mol/L～2.2×10-7mol/L浓度范围内与电化学发光强度呈线性关系,检测限为7.1×10-9mol/L。据此,讨论了氧还原增强鲁米诺ECL的机理并利用鲁米诺电化学发光监测氧还原过程。     

基于金-钯纳米粒子/石墨烯修饰电极测定药剂中的对乙酰氨基酚

利用电化学方法在石墨烯表面上沉积金-钯纳米粒子,制备了金-钯纳米粒子/石墨烯修饰玻碳电极.扫描电子显微镜和X-射线能谱仪对修饰电极组装过程进行了表征.采用循环伏安法研究了对乙酰氨基酚在修饰电极上的电化学行为,在p H 7.0的磷酸盐缓冲溶液中,对乙酰氨基酚在修饰电极上出现一对明显的氧化还原峰,其氧化还原峰电位分别为0.334V和0.299V.在最佳条件下,对乙酰氨基酚的氧化峰电流与其浓度在5.0×10-7-1.0×10-4mol/L范围内呈良好的线性关系,检出限(S/N=3)为1.0×10-7mol/L.利用该方法对药片中的对乙酰氨基酚含量进行检测,获得的结果令人满意.     

鲁米诺-过氧化氢化学发光体系测定雌性激素

报道了一种新的测定雌性激素的流动注射化学发光方法.在碱性条件下,金银复合纳米粒子能强烈地增强鲁米诺-过氧化氢化学发光,而天然雌性激素能明显的抑制金纳米溶胶催化的鲁米诺-过氧化氢体系的化学发光.据此,我们建立了测定天然雌激素(雌酮、雌二醇和雌三醇)的化学发光方法.在最优化的实验条件下,测定雌酮、雌二醇和雌三醇的线性范围分别为1.0×10-6-4.0×10-8,1.0×10-5-1.0×10-7和1.0×10-5-7.0×10-8.检测限分别为4.3×10-9mol·L-1,3.9×10-8mol·L-1和6.5×10-9mol·L-1,相应的相对标准偏差分别为 2.7%,1.8 %和2.3%.该方法用于孕妇尿样中雌激素总量的测定,结果令人满意.     

基于离子液体功能化碳纳米管负载金-铂纳米粒子的过氧化氢传感器

采用电化学沉积法将金-铂纳米粒子(Au-PtNPs)负载到离子液体功能化的碳纳米管(MWCNTs-IL)表面,构建了一种新型的过氧化氢(H2O2)传感器,采用循环伏安法(CV)、电化学阻抗法(EIS)对修饰电极进行表征.结果表明,电极表面双金属纳米粒子的存在极大地提高了电极的电化学性能,在最优实验条件下,过氧化氢的浓度与电流在1.0×10-9~1.2×10-7 mol·L-1范围内呈现良好的线性关系,检出限为4×10-10 mol·L-1.     

反相流动注射化学发光法测定姜黄素的研究

姜黄素对鲁米诺 过氧化氢 铬(Ⅲ)体系化学发光具有强烈的抑制作用,基于此首次建立了测定姜黄素的流动注射化学发光分析新方法.实验结果表明,在优化的实验条件下,化学发光信号强度ΔI与姜黄素的浓度在1.0×10-10～1.0×10-8mol/L范围内分段成良好的线性关系,方法检出限为5.0×10-11mol/L,相对标准偏差为2.8%(c=2.0×10-9mol/L,n=11).该法已应用于中药姜黄中姜黄素总量的测定.     

金/有机硅复合纳米颗粒修饰金电极的方波溶出伏安法测定痕量Hg(II)

采用3-巯丙基三甲氧基硅烷(MPTS)为单一硅源,以金纳米粒子(AuNPs)为MPTS水解凝胶颗粒的固着载体,制备了AuNPs/MPTS凝胶复合纳米粒子修饰电极.采用原子力显微镜及透射电镜观察纳米粒子的形貌及大小,并采用循环伏安法比较不同金纳米粒子含量对修饰电极电化学行为的影响.方波溶出伏安法试验表明,该修饰电极对Hg(II)的检测具有灵敏的响应,多种离子不产生干扰.在优化后的测试条件下,即在0.1mol/L的HCl溶液中,0.2V电位下富集15min,Hg(II)浓度分别为1×10-9~1×10-8 mol/L和5×10-8~5×10-7 mol/L时,溶出峰电流与Hg(II)浓度呈线性关系,相关系数分别为0.998 0和0.998 5.当富集时间为15min时,Hg(II)浓度检测限可达1×10-10 mol/L(信噪比为3),且所制备的复合纳米膜具有良好的导电性和电极重现性,可用以制作Hg(II)电化学传感器.     

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