用紫外双波长光度法同时测定水中酚类和苯胺类物质

紫外双波长光度法可以消除苯酚和苯胺的相互干扰 ,实现水中酚类和苯胺类物质的同时测定 ,所采用的双波长对为 2 0 9.0～ 2 39.8nm和 2 30 .0～ 2 5 3.5nm ,水样的 pH值应控制在 6 .6± 0 .2。水中K ,Na ,Ca2 ,Mg2 ,Cl-和OH-的浓度低于 2 0 0mg/L时不干扰酚类与苯胺类物质的测定 ,油类物质的干扰可通过萃取法消除。紫外双波长光度法测定酚类物质的线性范围为 0～ 2 0mg/L ,检出极限为 0 .0 5mg/L ;测定苯胺类物质的线性范围为 0～ 12mg/L ,检出极限为 0 .0 0 7mg/L。实际水样的加标回收实验和合成水样分析结果表明 ,本方法的相对误差绝对值小于 4.93% ,且操作简便、测试准确 ,可满足微量酚类和苯胺类物质的测定要求     

应用苯胺-α-萘酚分光光度法测定水样中的亚硝酸盐

实验研究了应用苯胺-α-萘酚分光光度法测定水样中的亚硝酸盐的含量。其原理为苯胺与亚硝酸钠在盐酸介质中重氮化,然后在NaOH溶液中与α-萘酚生成桔红色偶联产物。实验结果表明:偶联产物的最大吸收波长为480nm,线性范围是0～0.96mg/L,其线性回归方程相关系数为0.9976,表观摩尔吸收系数ε480为2.53×103L/(mol·cm),最低检出限为0.08mg/L,可用于水样中亚硝酸根的测定。     

还原紫外分光光度法测定水中NO-3

基于NO-3 在酸性介质中被锌粉还原后 ,溶液紫外吸收光谱将发生显著变化的原理 ,建立了测定水中NO-3浓度的还原紫外分光光度法。该方法采用的波长为 2 0 2 .0nm ,水样的 pH值控制为 7,以试样还原前后在该条件下的吸光度变化值ΔA对NO-3 溶液的浓度进行标定。还原紫外分光光度法测定NO-3 浓度的线性范围为 0～ 8.5mg/L ,最低检出限为 0 .0 2mg/L ,且F-、Cl-以及HCO-3 等常见离子对测定不产生干扰。地下水、自来水、雪水以及湖水等实际水样的测定结果及加标回收实验结果表明 ,该方法的相对标准偏差小于 2 .5 % ,加标回收率在 96 .3%～10 3.1% ,相对于标准方法 (紫外分光光度法 )的偏差为 - 4 .0 %～ 4 .0 %。该方法的精密度、准确度和灵敏度均较高 ,且操作简便 ,适用于饮用水以及污染较轻的湖水和地下水中NO-3 含量的测定。     

还原—紫还分光光度法测定水中NO3^—

基于NO3^-在酸性介质中被锌粉还原后,溶液紫外吸收光谱将发生显著变化的原理,建立了测定水中NO3^-浓度的还原－紫外分光光度法,该方法采用的波长为202．0nm,水样的pH值控制为7,以试样还原前后在该条件下的吸光度变化值ΔA对NO3^-溶液的浓度进行标定,还原－紫外分光光度法测定NO3^-浓度的线性范围为0－8．5mg/L,最低检出限为0．02mg/L,且F^-,Cl^-以及HCO3^-等常见离子对温室不产生干扰,地下水,自来水,雪水以及湖水等实际水样的测定结果及加标回收实验结果表明,该方法的相对标准偏差小于2．5％,加标回收率在96．3％－103．1％,相对于标准方法（紫外分光光度法）的偏差为4．0％－4．0％,该方法的精密度,准确度和灵敏度均较高,且操作简便,适用于饮用水以及污染较轻的湖水和地下水中NO3^-含量的测定。     

8-羟基喹啉偶联光度法测定水中亚硝酸盐

用8-羟基喹啉偶联光度法测定水中亚硝酸盐。在室温下,亚硝酸盐和苯胺反应生成重氮盐,在碱性介质中(pH≥12.5),重氮盐与8-羟基喹啉偶联显色,其最大吸收波长为482nm。线性范围为0～3.56mg·L-1,标准偏差小于2.5%,检出下限为7.4μg·L-1。该方法方便、快速、灵敏,用于水样分析,结果满意。     

紫外分光光度法测定环境水中的硝酸盐氮

本文基于硝酸盐氮在201.2nm处有强烈吸收,且干扰少,在PH=8碱条件下,建立了用紫外分光光度法直接测定水样中的硝酸盐氮的方法。硝酸盐氮在0～7.0mg/L范围内遵守比尔定律。加标回收率为99.1％～100.1％,检出限0.1000mg/L。可用于自来水,湖水中硝酸盐氮的测定,结果满意。     

紫外分光光度法测定饮食业油烟污染物的排放浓度

文章叙述了用紫外分光光度法测定饮食业油烟的最佳实验条件和方法。通过研究几种食用油的紫外光区吸收特征 ,选择210nm为最佳吸收波长 ,其工作曲线线性范围为10～100mg/L ,油烟最低检测浓度为0.8mg/m3。实际样品测定结果表明 ,该方法简便易行 ,准确性较好     

动力学荧光法测定痕量苯胺

目前测定苯胺的报道不多,主要有分光光度法[1]、电分析法[2]、色谱法[3],以上方法灵敏度欠佳.本文基于在磷酸介质中,痕量苯胺对过碘酸钾氧化罗丹明6G使其荧光猝灭具有抑制作用,建立了动力学荧光法测定痕量苯胺的新方法.方法的线性范围为0.010 1～0.183 mg/L,检出限为7.2 mg/L.本法灵敏度高,用于测定酚醛塑料管材和水样中苯胺的含量.     

荧光分光光度法测定水样中氧氟沙星的含量

采用荧光分光光度计分析了氧氟沙星的荧光特征及其在水样中含量。研究发现,在激发波长293 nm和荧光发射波长471 nm处p H=7的氧氟沙星水溶液具有最大荧光强度;在20~35℃范围内,氧氟沙星水溶液的荧光强度随温度升高而降低。当水样中无干扰氧氟沙星荧光特征的物质时,可在20℃、p H=7条件下,于激发波长293 nm和荧光发射波长471 nm处测定水样中氧氟沙星的含量,氧氟沙星的荧光强度与其浓度正相关,相关系数为0.9990,线性范围为0.05~1.0 mg/L,检出限为0.43μg/L,相对标准偏差小于1.6%(n=6),加标回收率为97.5%~100.9%,该方法适用于快速测定水样中氧氟沙星的含量。     

以SPE作为UV法测定硝酸盐氮的预处理方法

针对水样中有机物和浊度严重干扰紫外分光光度法测定硝酸盐氮的问题,分析了ENVI-18,LC-8,HLB(亲水亲油平衡)和自制PAC(粉末活性炭)四种固相萃取柱对水样中有机物和浊度等干扰的消除效果.研究结果显示:当进水水样DOC质量浓度为4mg/L时,自制PAC固相萃取柱和LC-8型固相萃取柱对水样中有机物的保留率均大于99.5%,而HLB和ENVI-18型固相萃取柱对有机物的保留率低于6.75%.ENVI-18和LC-8柱对水中硝酸盐氮不具有保留效果也不会向水中释放干扰硝酸盐氮的物质,PAC柱对水中硝酸盐氮具有强烈的保留作用,HLB柱则会向水中释放少量的干扰硝酸盐氮测定的物质.优选LC-8型固相萃取柱作为预处理小柱,并在宜兴西氿水上进行了应用,结果显示:加标回收率为94.0%~97.0%,相对标准偏差为3.14%.每支规格为500mg/3mL的LC-8型固相萃取柱能保留水中约0.75mg有机物(以DOC计),可处理10~15个水样,使用后的固相萃取柱可采用甲醇再生后再次使用.     

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.     

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