茜素紫光度法检测H2 O2／CO2+产生的羟自由基

研究了用茜素紫的氧化来显色测定Co2+-H2O2体系产生羟自由基(·OH)的方法,提出CO2+-H2O2-茜素紫分析新体系并用于羟自由基(·OH)的测定．本方法利用Co2+与H2O2反应,类似Fenton试剂产生羟自由基(·OH),并加入茜素紫显色剂,使茜素紫的颜色发生变化,采用紫外．可见分光光度计测定其△A值的变化,可间接测定羟自由基的含量,且灵敏度高．研究结果表明：在最大吸收波长560nm处,茜素紫的吸光度与·OH产生量成良好的线性关系;此外,抗氧化荆药物甘露醇、苯甲酸、硫脲与羟自由基清除率具有明显的量效关系,方法稳定性好。操作简便,测定快速,是一种简便的筛选抗羟自由基的清除剂和有效抗氧化剂药物的方法     

酸性介质中茜素黄R与牛血清白蛋白相互作用研究

在pH 3.0的酸性条件下,通过紫外-可见光谱法研究了茜素黄R与牛血清白蛋白的相互作用。茜素黄R与牛血清白蛋白形成的复合物最大吸收波长为384 nm,与茜素黄R的372 nm相比仅红移12 nm,故茜素黄R的加入对复合物吸光度的测定存在较大干扰。单波长法确定复合物的摩尔吸光系数为7.42×103L/(mol·cm)。双波长法计算得到茜素黄R与牛血清白蛋白的结合比例为2∶1,条件平衡常数K为2×105。同时讨论了酸性条件下影响茜素黄R与BSA结合比例的原因。     

催化动力学光度法测定痕量铁(Ⅲ)——茜素绿-H_2O_2指示反应体系

本法基于铁(Ⅲ)对过氧化氢氧化茜素绿反应的催化作用,提出一种高灵敏地测定痕量铁(Ⅲ)的新方法。该方法线性范围为2～36μg·L-1、40～1800μg·L-1检测限为6.04×10-7g·L～1。测定出反应表观活化能Ea=45.26kJ/mol。此法用于河水,自来水等样品中铁的测定,结果满意。     

催化动力学光度法测定痕量铁(Ⅲ)--茜素绿-H2O2指示反应体系

本法基于铁(Ⅲ)对过氧化氢氧化茜素绿反应的催化作用,提出一种高灵敏地测定痕量铁(Ⅲ)的新方法.该方法线性范围为2～36μg·L-1、40～1800μg·L-1检测限为6.04×10-7g·L-1.测定出反应表观活化能Ea=45.26kJ/mol.此法用于河水,自来水等样品中铁的测定,结果满意.     

过氧化氢-茜素体系催化光度法测定痕量铜的研究

研究了催化动力学褪色光度法测定痕量铜(Ⅱ)的新体系,反应介质为NH3·H2O-NH4Cl缓冲溶液(pH=10.0),催化体系为痕量Cu(Ⅱ)催化H2O2氧化茜素的褪色反应.考察了反应体系的适宜条件、动力学性质及28种干扰离子的影响,建立了一种催化动力学光度法测定痕量铜的新指示反应.本法的线性范围为0～1.2×10-7 g/mL,其灵敏度远远高于普通光度法,检出极限为1.76×10-10g/mL,可应用于农产品和蒙药中铜的测定,相对标准偏差为1.1%～3.2%.     

铀—茜素氨羧络合剂极谱络会吸附波的研究

在pH3.8的醋酸盐缓冲溶液中可得到铀—茜素氨羧络合剂的络合吸附波,铀(Ⅵ)最低检出量达3.0×10~(-7)mol/l。测定了络合物组成为铀(Ⅵ):ALC=1:2。研究证实电极过程为ECE过程。     

负催化动力学光度法测定痕量镍的研究

本文研究了稀氨水溶液中,镍(Ⅱ)负催化过氧化氢氧化茜素褪色的新指示反应及其动力学条件,建立了动力学光度法测定痕量镍(Ⅱ)的新方法,证明了本反应为一级反应,速度常数 k=-0.100 min~(-1),半衰期 t_(1/2)=6.93 min,表观活化能既 E_a=252.7 kJ/mol,其 Sandell 灵敏度为2.27×10~(-5)μg/cm~2,线性范围0～0.10μg/25 ml.该法用于测定饮用水和人发中的痕量镍(Ⅱ)获得满意的结果.     

三氯偶氮氯瞵与锆的显色反应研究——陶瓷釉料中锆含量的测定

引言文献报导通常测定锆的分光光度法有:邻苯二酚紫法、偶氮胂Ⅲ法、二甲酚橙法和茜素磺酸钠法等。邻苯二酚紫法测定锆的线性范围较宽(0～50μg/25ml),但要在酸性很低(PH=5.0～5.5)的介质中进行,这势必降低了对锆测定的选择性,后三种方法都是在酸性较高的介质中测定锆,其选择性较好,但是它们都存在比尔定律线性范围较窄的缺陷,这就给常量锆的分析带来稀释上的误差。偶氮胂Ⅲ法测定锆的酸度范围为1～3N,线性范围     

萃取浮选光度法测定Bi—Sr—Ca—Cu—O超导薄膜中的铋

研究了用萃取浮选光度法测定铋的各种条件,还试验了常见离子对本法的影响.研究发现:0～20μg/25ml 的铋符合比耳定律,络合物组成比铋∶茜素虹S∶亮绿为1∶3∶3,平均摩尔吸光系数为2.02×10~5.方法用于Bi-Sr-Ca-Cu-O 超导薄膜中的铋的测定,获得了较为满意的结果.     

光谱法研究Fe(Ⅲ)与茜素绿之间的相互作用

利用紫外-可见吸收光谱、荧光光谱和傅里叶红外漫反射光谱系统研究了Fe(Ⅲ)与茜素绿水溶液之间的相互作用,实验结果表明金属/配体摩尔比为1:3,茜素绿具有一定的光敏产生单线态氧的能力.Fe(Ⅲ)与茜素绿形成配合物后光稳定性降低,单线态氧量子产率明显提高.     

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.     

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of