硅钼蓝光度法测定铅锰铁中硅的含量

试样经硝酸溶解后,在0.1～0.6 mol/L的酸度下,使硅酸与钼酸形成黄色硅钼酸.然后加入草硫混酸消除磷的干扰,用硫酸亚铁铵将硅钼黄还原成硅钼蓝.通过采用配制与试样相同基体的办法,加入不同含量的硅标液来测定试样中硅的含量.     

高含量硅的快速分析方法研究

本文提出用二氧化二氢噻吩作β-硅钼酸的稳定剂,抑制向α-硅钼酸的转化,效果较丙酮好,并采用1-氨基-2-萘酚-4-磺酸与亚硫酸和抗坏血酸混合还原剂,促进硅钼蓝的还原,配合82型示差光度计,可在半小时内完成测定,本法可测含二氧化硅在50%以下的铝合金试样,方法快速、准确、重现性好。     

硅钼黄光度法测定油田产出水中低聚硅

建立了一种硅钼黄光度法测定三元复合驱产出水中低聚硅（单硅及一、二聚硅）的方法,研究了复杂体系三元复合驱产出水中低聚硅的定量分析．在pH值为1～2,波长在400nm处测定,硅含量在0～250mg·L^-1范围内呈良好的线性关系．此硅钼黄光度法简单易行,测定范围宽,具有一定的实用价值．     

还原硅钼酸盐分光光度法测定非合金钢和纯铁中微量硅

为配合河北理工学院和唐山钢铁公司合作开发新项目一连铸准沸腾钢的研制，研究试验了还原硅钼酸越界发光光度法测定非全金钢和纯铁中微量硅。改进后该方法简单、适用。且由经法测得结果与等离子体发射光谱得到的分析结果一致，应用于实际生产结果满意。本方法适用于非合金钢和纯铁中硅含量在０．００３－０．１００％硅的测定。     

硅钼杂多酸化学修饰电极伏安法测定土壤和煤碴中活性硅

本文报道硅钼杂多酸化学修饰电极的制备方法，应用于土壤、煤碴中活性硅的伏安法测定。ＳｉＱ２浓度在０．０５～１００．０ｍｇ／Ｌ范围内与峰高呈良好线性，检测限为０．０５ｍｇ／Ｌ。用山梨糖醇消除磷的干扰，测定了沃土、黄土和煤碴中活性硅含量。     

浅谈活性硅粉：可活性硅的测定

在没有标样的情况下,试样采取盐酸介质、硝酸介质比色法进行对比,且与氟硅酸钾容量法进行对比,结果表明活性硅粉——可活性硅的测定采用钼蓝光度法进行测定结果稳定、操作简单、快速,能满足分析要求。     

还原型硅钼酸盐光度法测定酸溶硅含量的方法验证

对最新颁布的GB223.5－1997还原型硅钼酸盐光度法测定酸溶硅含量的方法原理及有关条件进行了试验和分析，旨在从理论和实践两方面找出国标测定酸溶硅含量时的操作要点，提高分析结果的准确性。     

水泥中SiO2含量的快速测定

报道了一种用差示分光光度法中的标准加入法快速测定水泥中 Si O2 含量的方法。利用硅与钼酸铵生成硅钼黄 ,在酸性介质中和抗坏血酸还原剂作用生成硅钼兰 ,其最大吸收波长为 760nm,ε=2 .0 0× 1 0 4L/ (mol·cm)。     

用硫酸联氨还原、硫酸铈铵滴定钼的研究

本文用硫酸联氨还原、硫酸铈铵滴定测定钼酸铅试样中的钼，详细探讨了还原钼时的酸度和硫酸联氨用量、滴定钼的酸度、测定钼量、外加离子等试验条件。用选择条件测量约含１０ｍｇ钼酸铅试样，误差小于０．５％，相对标准偏差为０．２％。方法可用于测定用钼酸铅沉淀法初分离出来的、含有某些杂质的钼酸铅中的钼，也可用于钼溶液浓度的标定。图５，表１，参３。     

碳化硼微粉中微量硅的测定研究

本文依照硅钼蓝法原理,以抗坏血酸为还原酸,柠檬酸调节酸度还原硅钼黄,探讨碳化硼微粉中微量硅含量的测定方法,考察研究操作中各步骤的最佳工艺及其对硅含量分析精确度的影响。结果表明：本方法分析精度高且重现性好,适合于碳化硼微粉中微量硅（质量分数：0.01%～5%）的测定。     

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.     

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     

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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