硫代硫酸钠容量法测定铜阳极泥中的硒

本文介绍利用硫代硫酸钠容量法测定铜阳极泥中硒的含量。在含有酒石酸的6mol/l盐酸溶液中,用盐酸羟胺还原析出单体硒,过滤与其他金属分离,单体硒用酸溶解,于10﹪盐酸溶液中加入一定过量的硫代硫酸钠标准溶液,与亚硒酸反应生成四硫硒酸钠,以淀粉为指示剂,用碘标准溶液滴定过量的硫代硫酸钠,由消耗的硫代硫酸钠标准溶液的量计算硒的含量。     

碘定量法测定铊的研究

采用下列两种指施之一可以扩大Sill利Peterson的半微量碘定量法测定铊的范围,适用于半微量及常量铊的测定,结果的准确度较原法有所提高。 (1)在被滴定溶液里加入阿拉伯胶和乙醇,在Tl~+和硫代硫酸钠溶液浓度为0.005—0.05N时,相应加入15—40毫升1％阿拉伯胶溶液和5—20毫升95％的乙醇。 (2)在被滴定溶液内加入溴化钾,在Tl~+和硫代硫酸钠溶液浓度为0.05—0.1N时,最宜条件是:酸度0.2—1.0N,H_2SO_4;溴化钾1.0—1.5M;碘化钾0.0036—0.0055M:滴定后体积约70毫升。     

由不同硫含氧酸盐引发的氟烷基化内酯化反应

以4-氯八氟碘代丁烷和4-戊烯酸生成含氟丁内酯的反应为模板,详细研究了不同硫含氧酸盐、溶剂和温度对反应的影响。实验结果表明：以二氧化硫脲、雕白粉、亚硫酸钠、亚硫酸氢钠、偏重亚硫酸钠等硫含氧酸盐为引发剂,4-氯八氟碘代丁烷和4-戊烯酸的氢氧化钠水溶液与乙腈或DMF为共溶剂,于20～55℃搅拌反应3～15h,后处理并通过柱层析得到含氟内酯产物。以二氧化硫脲为引发剂,乙腈为共溶剂(V(乙腈)：V(水)=1：1),在35。C下反应5h,得到的含氟内酯产率最高(84．3％)。在此条件下,其他含氟碘代烷与4-戊烯酸反应,得到相应的含氟内酯化合物,收率为72．7％～86．2％。     

光动力学法测定食品中的亚硫酸盐

以亚硫酸盐与光化学反应产生碘的反应, 用于某些食品中痕量亚硫酸盐的测定． 标准加入回收率在 ９８％ ～１０５％ 之间, 相对标准偏差低于 ４％     

一株嗜热产孢子脱硫肠状菌的系统发育分析

从油田注水联合处理站里分离得到的一株嗜热、耐酸、异养型硫酸盐还原菌,编号为CW-01．该菌株兼性厌氧、革兰氏阳性、有极生鞭毛、直或弯曲的短杆状,能产孢子．主要生理生化特性包括：生长pH范围为2．8～11,最佳生长pH为5～6．5,最佳生长盐度为1．3％,最佳生长温度37℃,在15～50℃下培养基中均能使测试瓶有黑色沉淀物产生．如果以硫酸盐为电子受体,则可以在乙酸盐、丙酸盐、乳酸盐、丙酮酸盐、丁酸盐、琥珀酸盐、苹果酸盐、延胡索酸盐、戊酸盐、己酸盐、庚酸盐、辛酸盐、癸酸盐、十三烷基酸盐、十五烷基酸盐、棕榈酸盐、十七烷基酸盐、酵母粉和乙醇等电子供体中生长,也能够利用葡萄糖、果糖作为唯一碳源生长．在乳酸盐为电子供体时,能够在硫酸钠、硫代硫酸钠、亚硫酸钠等电子受体中生长．从腐蚀防治的角度对该菌株的腐蚀速率、耐1227性质以及生长曲线也进行了测定．通过16s rDNA测序(GenBank上的AC号为：AY742958)以及系列比对分析：该菌属于细菌界(Bactetia)、厚壁菌门(Firmicutes)、梭菌纲(Clostridia)、梭菌目(Clostridiales)、蛋白胨链球菌科(Peptococcaceae)、脱硫肠状菌属(Desulfotomaculum),与该属中的种Desulfotomaculum putei相似性达到98％．     

硫代硫酸钠滴定法测定碘

资料来源:参加全国盐碘外质控样测定考核1998年～2004年4次数据结果、2006年～2009年考核结果。测定方法:硫代硫酸钠直接滴定法。结果:各次考核均合格,但1998年～2004年4次测定值数值结果偏低。分析与评价:硫代硫酸钠直接滴定法测定食盐中碘含量准确,迅速,可靠,简单。外质控样测定考核结果虽然都合格,但前4次出现了负系统误差,产生原因是检验人员读数观察与颜色转变的终点判断有差异;2006年后外质控样测定考核结果呈随机误差。此外,应注意标准溶液水溶液挥发,稀释用水pH值过高或过低,淀粉指示剂加入过早等也是产生系统误差的原因。     

不同能源物质对At.f菌浸出低品位铜尾矿的影响

以嗜酸氧化亚铁硫杆菌LD-1菌株(At.f LD-1)为研究对象,研究硫酸亚铁、硫代硫酸钠和黄铁矿3种能源物质对At.f LD-1菌株浸出低品位铜尾矿浸出体系及铜浸出效率的影响.研究结果表明:At.f LD-1菌株浸出铜尾矿初期加入适量的硫酸亚铁、硫代硫酸钠、黄铁矿均能提高铜的浸出效率,其中以硫代硫酸钠的效果最为显著;初始加入二价铁质量浓度为5 g/L时浸出效果较好,46d铜浸出率达35.00%,与不加硫酸亚铁的相比提高13.63%;硫代硫酸钠中S质量浓度为1 g/L时浸铜效果最好,46d铜的浸出率达到38.10%,与不加硫代硫酸钠的相比提高23.70%;加入黄铁矿对提高铜浸出率也能起到促进作用,浸出46d后铜浸出率达34.17%,与不加黄铁矿时相比提高11.00%.     

卤水中碘离子的快速分析

卤水中碘含量很低,有大量的氯、溴离子共存。在有大量氯、溴离子存在下碘的分析方法文献中报导不少。Lassaigne J.L.,Strebinger R.,Dollak I.等根据 pd(Ⅱ)在1%的盐酸溶液中与碘离子生成碘化钯沉淀用重量法来测定碘的含量。该方法精度高,但整个分析操作历时二天之久,而且有机物和乙醇严重干扰测定;用HNO_2氧化碘离子为碘,用二硫化碳或氯仿萃取,直接用硫代硫酸钠标准溶液滴定有机相     

加碘酸钾食盐中碘含量的紫外分光光度法测定

根据碘(I2)、碘离子(I^-)和碘三离子(I3^-)的紫外吸收光谱。拟订了加碘酸钾食盐中碘含量的光度测定方法。在pH2．4，KI浓度为0．01mol／L的HCl介质中.1mol碘酸钾可定量转变为3mol I3^-，通过测量I3^-在288nm或350nm处的吸光度，可计算食盐样品中碘的含量。方法的加入回收率在96．8％～102．6％之间。本文中，笔者分析了2种市售碘盐样品，结果令人满意。     

复合高铁酸盐片剂的制备研究

用浓碱水溶液中次卤酸盐氧化法制备出黏糊状的高铁酸盐,加入粘土、无水硫酸钠与高铁酸盐制成不同比例的复合高铁酸盐,并对其溶出的高铁酸根浓度进行测定.探讨了黏土、无水硫酸钠的加入量及加入顺序对复合高铁酸盐稳定性的影响,找到了制备复合高铁酸盐片剂的最佳条件,在此条件下制备的复合高铁酸盐片剂具有较高的稳定性,研究结果极具工业应用...     

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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