抗盐性AA-AMPS共聚分散剂的合成

以丙烯酸(AA)与2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为共聚单体,过硫酸铵为引发剂,异丙醇为链转移剂,采用水溶液聚合法,合成了AA-AMPS共聚物.研究了引发剂用量、链转移剂用量及聚合反应温度等因素对聚合产物黏均分子质量的影响.实验结果表明,在n(AA)∶n(AMPS)=96∶4,引发剂质量分数(基于两种单体)为2%～5%,链转移剂质量比(基于两种单体)为0.30～0.95,单体质量分数(基于反应体系)为40%,反应温度在85～100℃,反应时间3 h的条件下,合成出了黏均分子质量在3900～10 000范围内的AA-AMPS共聚物.最后对产物进行了红外光谱分析.     

聚丙烯酸高吸水性聚合物的制备与性能

利用水溶液聚合法制备微孔状聚丙烯酸高吸水性聚合物,通过傅立叶变换红外分析(FTIR)和扫描电镜(SEM)表征其结构特征.研究引发剂质量分数、交联剂质量分数、单体中和度、反应温度以及反应时间对所制备吸水聚合物的吸水倍率的影响规律.结果表明,在引发剂质量分数为0.5%、交联剂质量分数为0.05%、单体中和度为80%和反应温度为60 ℃的条件下,仅用1 h即可成功制得微孔状聚丙烯酸高吸水性材料,其吸附蒸馏水倍率和吸附生理盐水倍率(质量分数0.9%)分别为468 mL/g和60 mL/g.     

压裂用疏水缔合型聚丙烯酰胺稠化剂的制备与表征

采用反相乳液法、氧化还原引发体系,合成了压裂用两性聚丙烯酰胺稠化剂.应用FT-IR初步表征了产品的结构.研究发现,当引发剂质量分数为0.8%(对单体),乳化剂质量分数为10%(对油相),m(油)∶m(水)为1.4∶1.0,聚合反应温度为40℃,单体n(AM)∶n(DMC)∶n(AA)为1.0∶0.6∶0.3,制得的两性聚丙烯酰胺相对分子质量可达528万.     

阳离子P(AM-DAC)污泥脱水剂的合成、表征与应用

采用无机引发剂和有机引发剂A作为复合引发剂,通过水溶液聚合法合成了高分子量阳离子聚丙烯酰胺P(AM-DAC)。优化合成条件为:无机引发剂质量分数0.15‰、有机引发剂A质量分数0.50‰、单体总质量分数30%、阳离子度40%和增溶剂B用量0.20‰。在该条件下,所得产物分子量为1.2×107,溶解时间为3h。IR分析证实了产物结构。DTA-TGA分析表明P(AM-DAC)在常温下不分解。浓缩污泥脱水实验结果表明:阳离子度为40%～80%的自制P(AM-DAC)均能取得良好的污泥脱水效果,滤液透光率大于92%,滤饼含水率低于68%。当投加量为1.47kg/tdrysludge时,分子量为1.2×107,阳离子度40%的P(AM-DAC)处理效果最好,滤液透光率达96.90%,滤饼含水率达64.50%。污泥脱水效果和处理成本优于国内污水处理厂一些常用絮凝剂。     

低热封包装材料用丙烯酸酯乳液的合成研究

针对双向拉伸聚丙烯薄膜(BOPP)包装材料,制备低热封丙烯酸乳液涂层材料.通过考察聚合工艺,调节单体比例、乳化剂、引发剂及其用量,测定乳液性能.研究结果表明:以十二烷基硫酸钠(K12)作为乳化剂,其适中的质量分数为0.5%,以质量分数为0.5%的过硫酸铵作为引发剂,软硬单体按质量比为1∶1混合,进一步加入质量分数为2%的功能性单体丙烯酸(AA),所制备的乳液稳定性较好,成膜性优异,热封强度达到2.64 N/cm,大大超过现有市场产品的性能.     

不同单体浓度范围反相微乳液聚合速率的比较

以油酸失水山梨醇酯Span80和壬基酚聚氧乙烯醚OP-10为乳化剂、过氧化二碳酸(2-乙基己酯)EHP为引发剂、白油为连续介质,进行了丙烯酰胺(AM)、丙烯酰胺/丙烯酸钠(AM/SA)和丙烯酰胺/(2-甲基丙烯酰氧乙基)三甲基氯化铵(AM/DMMC)反相微乳液聚合反应。研究了不同单体浓度范围内,3种单体(对)反相微乳液聚合速率。在较高单体质量分数范围内(w(M)为25%～50%),聚合速率对AM,AM/SA和AM/DMMC3种单体(对)浓度的反应级数分别为2.24,2.34和2.47;在较低单体质量分数范围内(w(M)为10%～26%)反应级数则分别为1.57,1.61和1.58。不同单体质量分数范围内聚合速率对单体浓度的反应级数相差较大,主要原因可能是聚合体系中单体水溶液的粘度对聚合速率有较大的影响。     

海藻酸钠改性膨润土/聚(丙烯酸钠-丙烯酰胺) 高吸水性复合材料的合成及性能

以丙烯酸和丙烯酰胺为单体,采用新型水溶液聚合法,制备海藻酸钠改性的膨润土/聚(丙烯酸钠-丙烯酰胺)高吸水性复合材料.采用正交实验,考察交联剂、引发剂、中和度、海藻酸钠、膨润土及单体质量比等因素对吸水倍率的影响.结果表明,当膨润土质量分数为30%时,该高吸水性复合材料仍可吸收自身重量1 200多倍的蒸馏水.傅里叶变换红外光谱(FTIR)与扫描电子显微镜(SEM)分析表明,单体与矿物结合良好.     

Si_3N_4陶瓷的凝胶注成型工艺

研究了微米级Si3N4 粉的凝胶注成型工艺 ,系统地分析了引发剂、单体及交联剂等对坯体性能的影响 .研究结果表明 ,当引发剂 (APS)的质量分数w(APS)达到 2 % ,单体与交联剂质量分数的比值在 10 %～ 30 % ,且溶液中有机单体的质量分数w(T)为 2 0 %时 ,坯体性能最佳 ,其强度最高可达 4 0MPa .否则 ,坯体内部的有机网络不均匀 ,将导致坯体性能的下降 .     

两种低阳离子度高相对分子质量PDA的制备

以二甲基二烯丙基氯化铵(DMDAAC)和丙烯酰胺(AM)为原料,过硫酸铵和亚硫酸氢钠复合物为引发体系,通过水溶液聚合法合成了10%和20%阳离子度DMDAAC和AM的共聚物(PDA)胶体产物。研究了单体质量、引发剂用量、聚合反应温度和Na4EDTA用量对产物特征黏度的影响。研究结果表明,在单体质量百分数为20%和37.5%,引发剂质量分数为3.0×10-4和5.1×10-5,聚合反应温度为45℃,Na4EDTA质量分数为2.0×10-4的最佳工艺条件下,10%和20%阳离子度PDA的特征黏度分别为17.1 dL/g和12.2 dL/g。2种反应单体的不同竞聚率导致其PDA产物最佳工艺参数的不同。     

高相对分子质量丙烯酸酯共聚物的制备及表征

以丙烯酸丁酯、丙烯酸乙酯和丙烯腈为主要单体,甲基丙烯酸羟乙酯和甲基丙烯酸羟丙酯为功能单体,采用悬浮聚合法制备高相对分子质量和高转化率的丙烯酸酯共聚物.考察引发剂种类和用量、聚合反应温度、分散剂类型和质量浓度、介质pH值等因素对聚合反应转化率和聚合物重均分子质量的影响,并用凝胶渗透色谱(GPC)、傅里叶变换红外光谱(FT-IR)和热重分析仪(TGA)对产物进行表征.结果表明:选择质量分数为0.66%的偶氮二异丁腈作为引发剂,质量分数为1.5%的自制无机-有机高分子(PVA混合物)作为分散剂,pH 值为7.5,65 ℃下聚合反应6 h,制得的共聚物重均分子质量可达6.86×10⁶,涂层抗渗水水柱高度超过2 000 mm,热分解温度为320 ℃,单体转化率为98.11%,聚合反应稳定,产品性状好.     

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