反相悬浮共聚法制备淀粉接枝丙烯酰胺絮凝剂及其在水处理中的应用

以环己烷为连续相,span-60为分散剂,硝酸铈铵/过硫酸钾(CAN/KPS)为复合引发剂,通过反相悬浮共聚法制备淀粉接枝丙烯酰胺絮凝剂.考察了引发剂用量、反应时间、单体用量、分散剂用量及反应温度等因素对接枝反应中单体转化率和接枝率的影响;并将该接枝共聚物用于对高浊度水的絮凝实验.结果显示接枝反应的最佳反应条件为:淀粉用量10 g,丙烯酰胺用量5 g,分散剂用量3 g,引发剂用量0.3 g(CAN/KPS＝0.5,摩尔比),反应温度70 ℃,反应时间2 h;絮凝实验表明该淀粉接枝絮凝剂对高浊度水具有良好的絮凝效果.     

在离子液体中合成淀粉基絮凝剂的研究

以淀粉和丙烯酰胺为原料,在离子液体氯化1-烯丙基-3-甲基咪唑中通过接枝共聚反应合成了丙烯酰胺-淀粉絮凝剂.研究了淀粉在离子液体和水中溶解情况的差异.通过傅立叶变换红外光谱证实了丙烯酰胺与淀粉分子发生了接枝共聚反应.考察了丙烯酰胺与淀粉的质量之比、引发剂用量、反应温度和时间对接枝共聚反应的影响.比较了在离子液体和水中合成得到的絮凝剂在高岭土悬浊液中的絮凝能力.     

一种用于处理洗煤废水的改性絮凝剂的研究

研究了一种用于处理洗煤废水的改性絮凝剂。在该絮凝剂的制备过程中单体质量比与原料配比的影响最为显著,其次为引发剂的浓度,最小的为反应温度。处理洗煤废水最适宜的改性絮凝剂合成条件:1)接枝共聚反应中:玉米淀粉5g、淀粉∶丙烯酰胺(质量比)=1∶4、去离子水150ml、0.5×10-3 mol/L的硝酸铈铵5ml、接枝反应温度为50℃、反应时间3h。2)阳离子化反应中:丙烯酰胺∶甲醛∶二甲胺(摩尔比)=1∶1∶0.5、反应温度75℃、反应时间2h。在洗煤废水的处理过程中,采用改性絮凝剂与硫酸铁复配处理洗煤废水效果较好,投药量分别为5mg/L、60mg/L。用其处理后的洗煤废水沉降性能好,透光率高,COD去除率高,水质得到大大改善。因此,本絮凝剂具有良好的应用前景。     

阳离子淀粉改性絮凝剂的合成及性能评价

以过硫酸铵/亚硫酸氢钠为引发体系,合成阳离子淀粉接枝丙烯酰胺、二烯丙基二甲基氯化胺(DADMAC)絮凝剂;采用正交试验确定淀粉接枝丙烯酰胺的最佳反应条件,引进阳离子单体DADMAC,合成一系列阳离子淀粉改性絮凝剂;以大庆油田三元复合驱污水为处理对象,考察阳离子淀粉改性絮凝剂的絮凝性能.结果表明:大庆油田三元复合驱污水适合在弱酸及中性的条件下处理,合适的pH值为6.0～7.0;单体DADMAC与可溶性淀粉质量比为1:9复配的絮凝剂效果最好,其质量浓度为50mg/L时,透光率达95%,对油、聚合物、悬浮物的去除达到了理想的效果.     

水溶性接枝聚多糖的研究Ⅰ．淀粉与丙烯酰胺和二甲基二烯丙基氯化铵的接枝共聚

采用自由溶液聚合法,以KMnO4/H^ 为引发体系,研究了淀粉与丙烯酰胺和二甲基二烯丙基氯化铵的接枝共聚反应,考察了引发剂用量、酸度大小、淀粉加入量、单体浓度、反应温度等条件对接枝反应的影响,并用红外光谱对产物进行了结构特征。     

FeSO4-H2O2引发的芋艿细粉与丙烯酰胺接枝共聚物的合成研究

利用 Fe SO4 - H2 O2 体系作引发剂 ,引发芋艿细粉与丙烯酰胺接枝共聚反应。探讨了反应温度、反应时间、H2 O2浓度、丙烯酰胺浓度对接枝共聚反应的影响 ,同时研究了接枝物作高分子絮凝剂 ,对硅藻土悬浊液、洗煤废水、酒糟离心液的絮凝沉降性能     

Starch-g-PAM絮凝剂的反相乳液合成及应用研究

以Span 80为乳化剂,过硫酸钾-尿素为引发剂,液体石蜡为油相,研究了淀粉与丙烯酰胺的反相乳液聚合.通过正交实验对各因素的考察得知油水比和乳化剂用量对实验的影响最大,其次是淀粉/丙烯酰胺(质量比)、引发剂用量,但搅拌速度和温度对实验的影响不太大.通过正交实验得出最佳反应条件为:油/水=1.2(体积比),淀粉/丙烯酰胺=1/2,乳化剂用量为(占整个连续相)6%,引发剂用量为1%,反应温度为40℃,搅拌速度为350 r.min-1,可得到最高接枝率为130%,最高接枝效率为93%,固含量为34.2%的接枝物,将所得接枝物处理造纸污水时,有较好的絮凝能力,且当絮凝剂投加量为30 mg.L-1时,絮凝效果最佳.     

淀粉-丙烯酰胺絮凝剂吸附铜、镉离子性能研究

为了研究淀粉-丙烯酰胺絮凝剂对铜、 镉离子的吸附性能,利用水溶液聚合法,以玉米淀粉、丙烯酰胺单体为原料合成淀粉-丙烯酰胺絮凝剂,并运用傅里叶红外光谱对絮凝剂的结构进行表征,同时考察絮凝剂用量、絮凝时间、pH值对铜、镉吸附性能的影响.结果表明:以硫酸铈为引发剂合成的淀粉-丙烯酰胺絮凝剂,当絮凝剂用量为0.5 g、絮凝时间...     

几种不同引发剂在玉米淀粉与丙烯酸接枝共聚中的应用

研究了以硝酸铈铵,过硫酸铵,过硫酸铵－亚硫酸氢钠为引发剂玉米淀粉与丙烯酸的接枝共聚反应,对一些反应条件如引发剂浓度,反应温度,单体浓度,单体中和度,反应时间等进行了考察,并比较了以硝酸铈铵,过硫酸铵,过硫酸铵－亚硫酸氢钠为不同经发体系的淀粉与丙烯酸接枝共聚反应的结果,表明用过硫酸铵－亚硫酸氢钠为引发剂的引发效果最佳。     

γ辐射法制备壳聚糖接枝共聚物及其絮凝性能

以壳聚糖(Cts)和甲基丙烯酸(MAA)为原料,应用γ射线辐射引发技术进行接枝共聚反应,制备了壳聚糖与甲基丙烯酸的接枝共聚产物(Cts-g-MAA),采用搅拌实验和测浊度法研究接枝改性壳聚糖对铅锌选矿废水的絮凝效果,其中考察了废水pH值、Cts-g-MAA的质量浓度、快速搅拌速度、慢速搅拌时间、静置时间对絮凝效果的影响,并将其与壳聚糖的絮凝能力进行了对比.实验结果表明,废水的pH值、絮凝剂质量浓度、搅拌速度、搅拌时间和静置时间均对絮凝效果产生影响,其最佳絮凝条件为pH值8.5、Cts-g-MAA浓度1.2mg/L、搅拌强度300 r/min、慢速搅拌时间为10 min、静置时间为11 min,此条件下的浊度去除率达98.6%.接枝改性壳聚糖的絮凝效果好于壳聚糖,且絮凝时的用量明显低于壳聚糖.     

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