方波极谱研究—Ⅵ悬汞电极阳极溶出伏安法测定高纯铝中痕量镉

试样0.1至0.2克,加入6N纯盐酸及少量纯汞,加热使样品溶解,蒸干至糊状,加入少量蒸馏水溶解,再次蒸干至糊状,加蒸馏水溶解,转移入10毫升容量瓶稀释至刻度。取溶液9毫升放入电解池中,于-1.0伏时预电解一定的时间,然后测定镉的阳极溶出电流,用加入法测定出镉的含量。用本法测定了高纯铝中10~(-7)％含量的镉。方法灵敏度高,准确度好。     

发泡法制备莫来石轻质耐火材料工艺研究

以黏土、工业氧化铝、石英砂为主要原料,采用发泡法制备莫来石轻质耐火材料,研究了发泡剂的种类、发泡工艺、耐火纤维加入量对莫来石轻质耐火材料性能的影响.结果表明,以十二烷基苯磺酸钠等为发泡剂,其加入量为1%时,试样的容重最轻;加入糊精可以提高试样烧结后的强度,最佳加入量为5%;而搅拌时间为8～11min或发泡温度为50℃时,试样烧结后强度最大.引入硅酸铝耐火纤维对试样的容重和气孔率影响不大,但可明显提高烧结后试样的强度,其加入量以1%为宜.     

镍在含硫氰酸根离子的硫酸溶液中电溶解的电流振荡

报道了镍在含硫氰酸根离子的硫酸溶液中电溶解的电流振荡新体系．实验结果表明,在硫酸溶液中,硫氰酸根离子的加入使镍在活化／钝化过渡区产生电流振荡,并且随着SCN^-浓度的升高或电极电势的降低,电流振荡周期逐渐变短．根据电化学实验和拉曼光谱测定结果,初步解释了镍在该介质中的阳极溶解行为和振荡机理．     

EDTA络合滴定法连续测定铅锌

采用盐酸和硝酸分解试样,使铅成K2SO4、PbSO4复盐沉淀与大部分干扰元素分离,过滤出复盐PbSO4,并将其溶解于HAc-NaAc缓冲溶液中,在pH =5.6 ～6时,以二甲酚橙为指示剂,用Na2EDTA滴定,所得结果为铅.滤液中加入甲基橙,用1＋ 1NH3＆#183;H2O中和至溶液成橙黄色,在pH =5.5时,以二甲酚橙为指示剂,用Na2EDTA滴定,测得结果为锌镉合量,减去镉量,即为锌量.本方法可同时连续测定铅、锌试样中的铅、锌.适用于含铅锌1％以上的试样测定.     

柠檬酸铅在柠檬酸钠溶液中溶解行为

通过氧化铅与柠檬酸反应制备了柠檬酸铅,考察了溶解时间、溶解温度、柠檬酸钠浓度和柠檬酸加入量对柠檬酸铅在柠檬酸钠溶液中溶解率的影响.结果表明:温度、柠檬酸钠浓度及柠檬酸加入量是主要影响因素,升高温度和提高柠檬酸钠浓度可显著提高柠檬酸铅溶解率;温度和溶解率呈正线性关系,拟合的线性方程为Y=0.76+0.63T;加入柠檬酸则对柠檬酸铅溶解有抑制作用.     

合金钢中钒的快速分析方法

将试样经磷酸溶解，加入过量硝酸破坏碳化物，并在高温条件下将钒定量氧化，经氧化后的五价钒用硫酸亚铁铵还原，根据硫酸亚铁铵的耗用量来计算试样中钒的百分含量．     

刚玉-尖晶石质浇注料烧成过程中的线膨胀行为

以电熔刚玉,氧化镁,硅微粉以及铝酸盐水泥为原料,制备了φ10 mm×50 mm的试样.在750~1450℃的温度下测量了试样的线膨胀率,研究了电熔刚玉粒度、氧化镁、水泥及硅微粉加入量对刚玉-尖晶石质浇注料烧成过程中线膨胀率的影响.研究结果表明:电熔刚玉粒度、氧化镁、水泥及硅微粉加入量对刚玉-尖晶石质浇注料的线膨胀率影响显著,增加电熔刚玉粒度和硅微粉的加入量,试样的线膨胀率减小,有效地抑制了刚玉-尖晶石质浇注料在烧成过程中的线膨胀行为;增加氧化镁和水泥的加入量,试样的线膨胀率呈增加趋势.     

用原子荧光光度计测定化妆品中的汞、砷含量

试样经酸加热消解后，在酸性介质中，试样中汞被硼氢化钾（KBH4）或硼氢化钠（NaBH4）还原成原子态汞，由载气（氩气）带入原子化器中，在特制汞空心阴极灯照射下，基态汞原子被激发至高能态，在去活化回到基态时，发射出特征波长的荧光，其荧光强度与汞含量成正比，与标准系列比较定量。试样经微波消解，加入硫脲使五价砷预还原为三价砷，再加入硼氢化钠或硼氢化钾使还原生成砷化氢，由氩气载入石英原子化器中分解为原子态砷，在特制砷空心阴极灯的发射光激发下产生原子荧光，其荧光强度在固定条件下与被测液中砷浓度成正比，与标准系列比较定量。     

镁铬砂中三氧化二铬含量的一种快速溶解测定方法

采用硫－磷混酸溶解镁铬砂试样测定三氧化二铬含量,对溶解测定中各种试剂的加入量进行了试验探讨,典混合溶剂熔融方法比较,简便,快速,经不同实验室试验对比分析,该方法准确,可靠、可用于进出口商品及相关行业检验的需要。     

抗汞菌株的筛选、鉴定及其特性研究

随着现代化工业的发展,环境中的汞污染量日益增加,严重影响人类生活质量,并威胁到人类健康,如何清除环境中的汞污染已成为一个世界性的热点与难题.从长期汞污染地区分离到一株菌株(YH16),其表现了对氯化汞极高的抗性(达到120 mg/L),通过16S rDNA鉴定为溶解肠杆菌,命名为Enterobacter dissolvens sp.YH16.研究发现,该菌株有较宽的生长温度(25～45℃)和pH范围(7～9.5),其中生长的最适温度为30℃,最佳pH值为8.0,在最适条件下能稳定处理培养基中的汞,24 h去汞效率达70%以上.该菌株在解决因无机汞引起的环境污染问题上,具有良好的应用前景.     

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.     

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     

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