一种耐盐保水剂的制备及其性能研究

采用水溶液聚合法,以N,N′-亚甲基双丙烯酰胺为交联剂,过硫酸铵为氧化还原引发剂,乙二胺四乙酸为螯合添加剂,丙烯酰胺和部分中和的丙烯酸为单体,制成用于荒漠化防治的交联型耐盐高吸水树脂,研究了交联剂、螯合剂、氧化还原引发剂及中和度等对该高吸水树脂的吸水性和吸盐性的影响。结果表明:使用EDTA作为螯合添加剂,树脂的吸收率有明显提高,吸水(自来水)率和吸盐率分别达到900 g/g和190 g/g以上;改变交联剂、氧化-还原引发剂用量能提高树脂的吸盐性;中和度对树脂的吸水性有一定影响,但对吸盐性没有明显影响。     

超声辐射技术合成半纤维素-丙烯酸接枝共聚高吸水树脂

以粘胶纤维生产过程中产生的半纤维素废碱液为主要原料,丙烯酸(AA)为接枝单体,N,N’-亚甲基双丙烯酰胺(NMBA)为交联单体,(NH4)2S2O8-NaHSO3为氧化还原引发体系,利用超声辐射技术合成半纤维素-丙烯酸接枝共聚高吸水树脂,并对其合成条件、结构及吸液能力进行了探讨。结果表明:在优化条件下合成的树脂吸蒸馏水率为311g/g,吸自来水率为102g/g,吸生理盐水率为55g/g,吸人工尿液率为31g/g,具有优良的吸水速率和保水能力。红外光谱及扫描电镜分析结果表明合成了具有蜂窝状网络结构的高吸水树脂。该树脂的成功合成,意味着半纤维素废碱液有望得以高效利用,变废为宝,为高吸水树脂的合成提供一种新的原料。     

反相悬浮法合成聚(丙烯酸钠-丙烯酰胺)高吸水树脂及性能研究

高吸水性树脂由于在农业、生理卫生和化学工业等领域的广泛用途近来得到广泛的观注.本文以丙烯酸和丙烯酰胺为共聚单体,N,N'-亚甲基双丙烯酰胺为交联剂,Span-60为悬浮稳定剂,采用反相悬浮聚合法合成了聚(丙烯酸钠-丙烯酰胺)高吸水树脂.探讨了交联剂浓度、悬浮稳定剂浓度、中和度和不同单体配比等对树脂吸液率的影响,以及树脂的吸液速率.结果表明,合成得到的高吸水树脂对去离子水、0.9%生理盐水和人工血液的吸收率分别达到1100g/g、90g/g和75g/g.     

微波法合成淀粉/AM/AMPS高吸水性树脂的研究

对不加引发剂和无氮气保护情况下微波辐射合成共聚高吸水性树脂进行研究。以N,N′-亚甲基双丙烯酰胺(NM BA)为交联剂,采用水溶液聚合法合成淀粉/丙烯酰胺(AM)/2-丙烯酰胺-2-甲基丙磺酸(AM PS)共聚高吸水性树脂,研究了单体配比,反应pH值,交联剂用量,淀粉含量及微波辐射功率对树脂吸水率的影响。结果表明在最优条件下得到的吸水树脂最大吸蒸馏水率为2 260 g/g,FT IR和偏光分析证实合成的树脂为网状接枝共聚物。     

单纯形法合成耐盐高吸水树脂

以丙烯酸和丙烯酰胺为单体,N,N’-亚甲基双丙烯酰胺为交联剂,以过硫酸铵和亚硫酸氢钠体系为引发剂,采用水溶液聚合法合成耐盐高吸水树脂。运用单纯形优化法获得了单体配比、丙烯酸中和度、引发剂用量、交联剂用量的优化条件组合,树脂在0.9%NaCl溶液中的最高吸盐水率达143.9 g.g-1。还考察了溶液盐浓度、pH值和温度等对树脂吸液性能的影响。     

聚丙烯酸钠高吸水树脂的新工艺合成研究

以丙烯酸及其钠盐为单体,以过硫酸钾为引发剂,N,N′-亚甲基双丙烯酰胺为交联剂,采用不通氮气及不除去丙烯酸中阻聚剂的新工艺,通过接枝聚合合成了聚丙烯酸钠高吸水树脂。文章研究了丙烯酸的中和度、引发剂用量及交联剂用量对聚丙烯酸钠高吸水树脂吸水率的影响,并通过正交实验对该产品进行了最优化合成工艺条件的研究。实验研究表明,以该新工艺合成的聚丙烯酸钠高吸水树脂的最高吸蒸馏水率为1 060g/g。     

光聚合法合成聚丙烯酸-丙烯酸钠高吸水性树脂

以丙烯酸为原料,N,N'-亚甲基双丙烯酰胺为交联剂,采用光聚合的方法合成了聚丙烯酸-丙烯酸钠高吸水性树脂,并对光引发剂用量、曝光时间、丙烯酸中和度以及交联剂用量等对光聚合反应的影响和对产物吸水性能的影响进行了研究。所制得的吸水性树脂吸水率达1550mL/g,对0.9%NaCl溶液的吸液率为160mL/g。     

淀粉/AMPS/DMC高吸水树脂的合成及其吸水保水性能研究

以淀粉、2-丙烯酰胺-2-甲基丙磺酸(AMPS)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为原料,(NH4)2S2O8为引发剂,N,N’-亚甲基双丙烯酰胺(MBAM)为交联剂,通过水溶液聚合法制备高吸水树脂。采用红外光谱和扫描电镜对树脂的结构进行了表征分析。考察了AMPS与DMC比例、p H值以及淀粉、引发剂、交联剂用量等条件对树脂的吸水、吸盐水倍率的影响,结果表明,在最佳条件下,树脂吸水率为698 g/g,吸盐水(浓度0.9%)倍率为86 g/g。同时,树脂的土壤保水性能结果表明,淀粉/AMPS/DMC高吸水树脂的加入大大改善了土壤的保水性能,当树脂用量为0.25 g/50 g时,土壤的保水时间后移,不同土壤在自来水中的饱和含水率提高了4.02~5.73倍,在盐水(浓度0.9%)中的饱和含水率提高了1.70~2.04倍。     

分步法合成SA-IP-P(AA/AM)互穿网络高吸水性树脂及其性能研究

以淀粉接枝丙烯酸共聚物SA为互穿物,以丙烯酸(AA)、丙烯酰胺(AM)为聚合单体,N,N’-亚甲基双丙烯酰胺(NMBA)为交联剂,采用(NH4)2S2O8-NaHSO3氧化还原引发体系,通过分步法制备SA-IP-P(AA/AM)互穿网络高吸水性树脂。其适宜反应条件为:w(丙烯酰胺/丙烯酸)=0.4;丙烯酸中和度85%;引发剂用量0.32%;交联剂用量0.035%;SA用量8%.在此条件下合成的SA-IP-P(AA/AM)树脂吸去离子倍率和吸0.9%NaCl盐水倍率分别可达到1 480 g.g-1和120 g.g-1.通过红外光谱、扫描电镜、透射电镜和X射线衍射等测试研究了产物中互穿聚合物网络结构,结果显示在保持已有树脂优良性能的基础上,进一步改善了高吸水树脂的保水性能、耐盐性和对环境中水分的应答性.     

两性聚电解质型高吸水树脂的合成及溶胀性能研究

用溴己烷和甲基丙烯酸二甲胺基乙酯(DMAEA)合成N,N'-二甲基,N-己基甲基丙烯酰氧乙基溴化铵(DMAEA-HB),再采用这种含有烯丙基结构的不饱和季铵盐、丙烯酸(AA)和丙烯酰胺(AM)为原料,以过硫酸钾-亚硫酸氢钠(K2S2O8-NaHSO3)为引发体系,采用反相悬浮聚合法合成含有阴阳离子的两性聚电解质高吸水树脂(SAP),讨论了引发剂、交联剂、丙烯酸、丙烯酰胺、季铵盐用量、外部溶液pH值等因素对树脂吸液性能的影响.结果表明:在丙烯酸/丙烯酰胺(摩尔比)为1:1,季铵盐含量为2%,丙烯酸中和度为75%,交联剂用量为0.01×10-2(占单体的摩尔比),引发剂用量为1.00×10-3(K2S2O8/NaHSO3=1/1.1),反应温度为74℃的条件下,制得的SAP吸去离子水可达1 440g/g,吸0.9%的NaCl溶液为118g/g.与一般聚电解质高分子相比,两性聚电解质型吸水树脂的吸水率受外部溶液pH值的影响更为敏感.     

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     

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