分光光度法测定景德镇焦化厂废水中铬

介绍用分光光度法测定含铬量较高的废水。在酸性条件下，铬与二苯碳酰二肼生成紫红色的配合物，最大吸收波长的540nm。该方法具有简便、快速、应用范围广等特点。     

改进的二苯碳酰二肼分光光度法测定茶叶中的六价铬

对二苯碳酰二肼分光光度法测定六价铬方法中显色剂进行简化改进，提高了分析效率，将改进的方法用于茶叶中微量铬的测定，与标准方法比较，测定结果相似。     

酸体系对光度法测定水中Cr^6＋结果的影响

通过比较3种酸体系及同一酸体系不同酸度下二苯碳酰二肼光度法测量水体中6价铬的研究,发现体积分数为5%的盐酸作检测体系时,分析效果最好,显著增大了Cr（VI）的线性范围,方法的重现性和准确性得到了很好的保证。该方法成本低、过程简单、分析速度快、便于操作,为二苯碳酰二肼光度法测水中6价铬提供了新的思路。     

二苯碳酰二肼分光光度法测定鸡饲料中的微量铬(Ⅵ)

采用二苯碳酰二肼分光光度法测定鸡饲料中微量铬(Ⅵ)。经试验确定最佳试验条件为:1∶1磷酸0.5mL,1∶1硫酸0.3mL,波长为540nm。铬的含量在0.008~0.4μg·mL-1范围内与吸光度A呈良好的线性关系,标准工作曲线为y=0.0112x+0.019,相关系数为r=0.9996。加标回收率为99.59%~101.12%。此方法操作简单,测定快速,测定结果的准确度和精密度较高。     

用分配法研究铬(Ⅵ)与二苯碳酰二肼配合物

本文在硫酸介质中使Cr(Ⅵ)与二苯碳酰二肼(DPC)生成紫红色配合物,研究了它的生成条件、组成、稳定性及光学性质;计算了不同络合剂浓度条件下生成配合物的百分数;为提高光学测定灵敏度,对该配合物进行了萃取研究,优选了萃取剂及萃取条件,探讨了有关的萃取行为,计算了分配比,结果表明本文选定的萃取体系萃取效果良好。     

典型矿业城市土壤重金属污染的垂直分布规律研究——以武安市为例

选取镉、砷、铬、铅4种元素作为土壤污染特征因子。运用原子吸收光谱仪、采用KI–MIBK萃取原子吸收分光光度法测定镉(Cd)、铅(Pb)浓度;运用分光光度仪、采用二苯碳酰二肼分光光度法测定铬(Cr)浓度;运用原子荧光仪、采用原子荧光光度法测定砷(As)浓度。采用EXCEL软件和SPSS统计软件分析处理监测数据,得出该地区重金属污染垂直分布规律。     

水质六价铬二苯碳酰二肼分光光度法测定不确定度的评估

通过二苯碳酰二肼分光光度法测定水质六价铬过程的分析，对测定不确定度作出评估，得出影响测定结果的几种重要因素。     

皮革废渣渗漏液中铬的测定

对皮革废渣(蓝皮屑)渗漏液中铬的二苯碳酰二肼分光光度测定法进行了研究，结果表明此方法的线性范围0-0.400mg／L，吸光度A对浓度c(mg／L)关系回归方程为：A=0．779c-0．0005，线性相关系数为0．9993，检出限为0．007mg／L，相对标准偏差小于3％，加标回收率为100％～105％，用此法对废渣渗漏液中铬的测定表明铬的形态为三价铬，因此，测定总铬时需先加H2SO4-HNO3进行消解，再以KMnO4氧化，二苯碳酰二肼显色，分光光度法测定．     

用高分子胺萃取光度法测定微量铬(Ⅵ)

本文研究了用N-235萃取光度法测定微量铬(Ⅵ)。在该方法中,于0.2—1N硫酸溶液中将Cr(Ⅵ)萃取入N-235有机相,直接以二苯碳酰二肼在有机相显色,并建立了萃取光度测定Cr(Ⅵ)的最佳条件。本法成功地用于铁矿、河水和废水中铬的测定。     

二苯碳酰二肼分光光度法测定无组织废气中铬酸雾的测量评定

建立二苯碳酰二肼分光光度法测定无组织废气中铬酸雾不确定度的评定方法,分析不确定度的来源,并对各不确定度分量进行量化。结果表明,影响无组织废气中铬酸雾测量不确定度主要因素为标准工作曲线的拟合及样品测量重复性引入的不确定度,污染物浓度较低时,测量仪器引入的不确定度较大。     

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.     

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.     

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     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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