醇-盐双水相技术去除水中的对氨基酚

研究了丙醇–硫酸铵双水相体系分离水中对氨基酚的新方法,考察了萃取体系中的硫酸铵用量、正丙醇用量、pH值对萃取率的影响,通过L9(33)正交试验对萃取条件进行了优化.确定萃取条件为:pH值为4.5,硫酸铵用量为15.0 g,正丙醇为20 mL,在最佳条件下经过3次连续萃取,萃取率达99.41%.改进了分光光度法测定对氨基酚含量的方法,实验结果表明该方法快速、准确、萃取率高,处理过的含对氨基酚的水样达到GB8978—1996中的一级标准.     

改性硅胶分离富集-X射线荧光能谱法测定金精矿中的金

硅胶通过L-半胱氨酸修饰后得到改性硅胶,改性硅胶对金元素具有很强的吸附作用,将其作为分离富集手段,结合薄样技术-X射线荧光能谱法,可用于检测金矿中的金含量.本研究优化了包括pH值、洗脱液的种类、洗脱液的体积、最大吸附容量、最大富集倍数等参数.在最优条件下,金元素的最大富集倍数为100,检出限为0.017μg/mL.本方法可应用于金精矿样品中金的测定.     

分散液液微萃取—分光光度法测定水中痕量汞

以四氯化碳为萃取剂,丙酮为分散剂,硫代米式酮(Thio-Michler’s ketone,TMK)为汞的螯合剂,建立了水中痕量汞分散液液微萃取—分光光度法测定的新方法.对分散液—液微萃取条件和分光光度法测定的最佳实验参数进行优化,包括溶液的pH值,萃取剂与分散剂的种类与用量,螯合剂硫代米式酮的用量,萃取时间等.在最佳实验条件下,汞的浓度在110～420 ng/mL范围内与吸光度呈良好线性关系,相关系数r=0.998 1,富集倍数为30,检出限为55 ng/mL,相对标准偏差(RSD)为4.2%(n=8),回收率为92%～108%.实验结果表明,该方法简便,快速,回收率高,成本低、富集效率高且对环境友好,适用于水中痕量金属汞的测定.     

新型气相色谱分析样品前处理装置与方法

探索一种新型的样品前处理装置,运用载体、携带体和综合蒸馏技术完成了待测样品中微量成分的提取分离和富集.将冷端接受器设计为可更换结构,所以无样品交叉干扰,适用于痕量组分的富集.在乙酸乙酯中添加了4种微量有机磷农药后进行了前处理其装置能自动将微量组分富集到2mL邻苯二甲酸二甲酯中利用气相色谱分析的结果,研究了样品前处理装置分离富集参数的选择原则.实验证实该方法能最有效地除去蛋白、脂肪、色素等对气相色谱分析有干扰的组分;将待测微量组分的浓度富集150倍以上;回收率92%～117%;相对标准偏差±5.65%;最小检出线为1 ng/mL.有机试剂的回收利用率大于95%,而且操作简单方便,以模拟试样为例说明了方法的实用性.     

辣椒叶片中类胡萝卜素组分分离及测定方法的研究

建立辣椒叶片中类胡萝卜素组分及其含量的分离测定方法.通过对提取溶剂、皂化温度、皂化时间、KOH-乙醇皂化液质量浓度、KOH-乙醇皂化液体积、料液比的选择,以及对流动相、柱温、柱流速等色谱条件的考察,研究提取辣椒叶片类胡萝卜素工艺流程.建立了提取辣椒叶片中类胡萝卜素的适宜工艺和分离测定辣椒叶片中类胡萝卜素组分及其含量的RP-HPLC工艺.技术关键是:以石油醚为提取溶剂、皂化温度为80℃、皂化时间为40min、皂化液质量浓度为20%、皂化液体积为10mL、料液比为1∶5;采用YMC-C30色谱柱(250mm×4.6mm i.d,5μm);检测波长450nm;柱流速1.0mL·min-1;柱温25℃;流动相A为乙腈:甲醇(V∶V=60∶40),流动相B为甲基叔丁基醚(100%),梯度洗脱.结果表明以外标法定量,叶黄素、玉米黄素和β-胡萝卜素各组分的线性关系良好,相关性系数在0.996 1~0.999 9之间;平均回收率在85.2%~95.1%之间.该方法为辣椒叶片中叶黄素、玉米黄素和β-胡萝卜素的分离与定量测定提供了方法保证.     

巯基棉富集金的研究及测定

本文对巯基棉柱富集金的主要条件进行了实验研究。该法简单快速,选择性好,灵敏度和准确度较高,用于地质样品中金含量在0.X—XX.0g/T的富集及测定,结果比较满意。     

D_(293)固相萃取分离/ICP-AES在线测定环境样品中铀

采用微色谱柱技术对环境样品中的铀进行分离富集,分析了影响其分离富集的条件,并以ICP-AES为检测仪器,对环境样品中铀的含量进行了准确测定,建立了D293固相萃取分离/ICP-AES在线测定环境样品中铀的方法。实验表明,pH=1.5时,铀可被树脂完全吸附,10mL0.9mol/LNH4NO3-0.1mol/LHNO3可完全解吸铀,浓缩物用ICP-AES进行测定,检出限、相对标准偏差和相对误差分别为0.05μg/mL,0.8%～2.9%和0.4%～9.8%。方法简便、快速、准确,适合于各种环境样品中微量铀的测定。     

紫外分光光度法测定草珊瑚饮料中总黄酮的含量

目的 利用类黄酮在一定条件下能与Al3+发生反应形成有色配合物.探索紫外可见分光光度法测定类黄酮的最佳实验条件,并对草珊瑚饮料中总黄酮的含量进行测定.方法 以总黄酮的含量作为分析指标,利用单因素实验并结合正交实验对紫外可见分光光度法测定总黄酮进行优化.结果 草珊瑚饮料中总黄酮的含量最优检测条件为:以70%乙醇为溶剂,加5% NaNO2溶液1 mL、10% Al(NO3)3溶液1 mL以及4% NaOH溶液10 mL,静置15 min,测得草珊瑚饮料总黄酮含量的相对误差为0.044%;回收率实验结果显示,在总黄酮含量为0.5~4.0 mg/mL范围内,其回收率为98.6%~101%,表明此方法可靠.结论 紫外可见分光光度法适用于草珊瑚饮料中总黄酮含量的测定,此方法具有操作简便,快速准确之特点,具有一定推广应用价值.     

一次性塑料餐具中尼泊金酯迁移量的测定

该文建立了RP-HPLC法快速测定一次性塑料餐具中尼泊金甲酯、尼泊金乙酯、尼泊金丙酯、尼泊金丁酯和尼泊金异辛酯迁移量的方法.优化了色谱分离和分析条件,采用Diamonsil C₁₈(150 mm×4.6 mm×5 μm)色谱柱分离,用甲醇-水体系梯度洗脱,检测波长为254 nm,流速为1.0 mL·min^-1,柱温为30 ℃.该方法的线性范围为5～1 000 ng·mL^-1(R>0.99),检出限为0.37～0.52 ng·mL^-1,重现性良好,日内及日间重复测定的相对标准偏差分别为4.0%～5.3%、4.3%～7.5%.该方法成功应用于塑料杯、塑料碗、塑料盘等一次性塑料餐具中5种尼泊金酯迁移量的测定.     

采用非水电位滴定法测定TRODAT-1盐酸盐含量

建立测定TRODAT-1盐酸盐含量的非水电位滴定方法.通过选择滴定剂及溶剂体系,确定适当的滴定剂和溶剂,增大其滴定终点突跃.研究结果表明:以2 mL冰醋酸加18 mL醋酐为溶剂,高氯酸-冰醋酸标准溶液(0.02 mol/L)为滴定剂,以电位法确定滴定终点为最佳实验条件,样品易溶解,电位突跃大,与使用醋酸汞试液相比,溶液澄清透明,而且减少了汞污染,有利于环境保护.该方法具有较高的准确度与精密度,相对标准偏差(RSD)为0.29%;该方法简便、快速、准确,不需贵重精密仪器,适用于TRODAT-1盐酸盐的质量控制.     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has