多层壳核结构ACR树脂的合成与性能研究I．乳化剂对ACR乳液聚合反应及PVC／ACR共混物性能的影响

研究乳化剂的种类、复配比例及质量分数对聚丙烯酸正丁酯／聚苯乙烯／聚甲基丙烯酸甲酯（ACR）壳核乳胶粒径、PVC／ACR共混物性能的影响。结果表明3种阴离子乳化剂十二烷基硫酸钠（K12－Na)、十二烷基磺酸钠（SDS）、十二烷基苯磺酸钠（SDBS）中,合成的ACR乳胶粒子粒径依次增大,PVC／ACR共混物的抗冲强度增大。将十二烷基苯磺酸钠与非离子型乳化剂壬基苯聚氧乙烯醚（OP－10）复配使用时,随着非离子乳化剂OP－10质量分数的增加,ACR乳液聚合各阶段乳胶粒子粒径均相应增大,PVC／ACR共混物的抗冲强度增大。ACR粒子的粒径都随着乳化剂浓度的增中而降低,而粒径大小分布加宽,PVC／ACR共混物的抗冲强度降低,PVC／ACR共混物的透光率升高。     

多层壳核结构ACR树脂的合成与性能研究

研究乳化剂的种类、复配比例及质量分数对聚丙烯酸正丁酯/聚苯乙烯/聚甲基丙烯酸甲酯（ACR）壳核乳胶粒径、PVC/ACR共混物性能的影响.结果表明3种阴离子乳化剂十二烷基硫酸钠(K12-Na)、十二烷基磺酸钠(SDS)、十二烷基苯磺酸钠(SDBS)中，合成的ACR乳胶粒子粒径依次增大，PVC/ACR共混物的抗冲强度增大.将十二烷基苯磺酸钠与非离子型乳化剂壬基苯聚氧乙烯醚（OP-10）复配使用时，随着非离子乳化剂OP-10质量分数的增加，ACR乳液聚合各阶段乳胶粒子粒径均相应增大，PVC/ACR共混物的抗冲强度增大.ACR粒子的粒径都随着乳化剂浓度的增加而降低，而粒径大小分布加宽,PVC/ACR共混物的抗冲强度降低，PVC/ACR共混物的透光率升高.     

聚氯乙烯与增韧剂及加工助剂共混体系的流变性能

采用共混方法在PVC中渗混CPE、ACR及其他配料,以改善硬PVC的脆性和熔体流动性。本文研究这一共混体系中各组份用量对熔体流动性能及制品力学性能的影响。实验结果指出,为得到最好的结果,CPE用量在10份以内,ACR不超过5份。而且预示CPE含量在15份以上时,共混物有形态上的转变。ACR与CPE在改善PVC加工性能上有不同的机构。     

多层壳核结构ACR树脂的合成与性能研究Ⅰ.乳化剂对ACR乳液聚合反应及PVC/ACR共混物性能的影响

研究乳化剂的种类、复配比例及质量分数对聚丙烯酸正丁酯 /聚苯乙烯 /聚甲基丙烯酸甲酯(ACR)壳核乳胶粒径、PVC/ACR共混物性能的影响 .结果表明 3种阴离子乳化剂十二烷基硫酸钠 (K12 -Na)、十二烷基磺酸钠 (SDS)、十二烷基苯磺酸钠 (SDBS)中 ,合成的ACR乳胶粒子粒径依次增大 ,PVC/ACR共混物的抗冲强度增大 .将十二烷基苯磺酸钠与非离子型乳化剂壬基苯聚氧乙烯醚 (OP -1 0 )复配使用时 ,随着非离子乳化剂OP -1 0质量分数的增加 ,ACR乳液聚合各阶段乳胶粒子粒径均相应增大 ,PVC/ACR共混物的抗冲强度增大 .ACR粒子的粒径都随着乳化剂浓度的增加而降低 ,而粒径大小分布加宽 ,PVC/ACR共混物的抗冲强度降低 ,PVC/ACR共混物的透光率升高 .     

PVC加工助剂ACR—TG4型

PVC 加工助剂丙烯酸酯类共聚物(简称:ACR)是以甲基丙烯酯、丙烯酸酯为主要原料,采用乳液聚合工艺制成的新型塑料加工助剂。ACR—4型主要用于食品包装袋,透明塑料薄膜及硬质 PVC 制品的成型加工中。该助剂与 PVC 有良好的相溶性,能有效地改善物料的塑化程度,缩短 PVC 的溶融时间,还能增强物料的流动性及提高制品的表面光洁度,并保持 PVC 的原有性能。产品质量达到国外同类产品的水平。     

PVC／MBS共混物熔体毛细管流变性能研究

研究不同配比的轻度交联MBS与PVC共混物的毛细管流变性能,建立了PVC/MBS共混物粘度,剪切力以及温度关系的数学模型,同时从理论上分析了PVC/MBS的微观相作用。     

ACR冲击改性剂的研制及应用

采用种子乳液聚合的分步聚合法,制备了具有核壳结构的丙烯酸类树脂(ACR)。以ACR作为PVC的抗冲击改性剂,通过对改性PVC的冲击强度、熔融时间、扭矩等参量的测定,考察了ACR中单体配比、乳化剂及交联剂含量对PVC抗冲击性能的影响,并对改性过程中PVC的加工流变学进行了研究。结果表明,所制备的ACR改性剂可明显改善PVC的抗冲击强度,同时也改善了PVC的加工性能。     

纳米级CaCO3对聚氯乙烯/丙烯酸酯橡胶的增韧改性

采用丙烯酸酯橡胶(ACR)、纳米级CaCO₃对聚氯乙烯(PVC)进行增韧改性,并对该体系的断裂面形貌和加工流变性能进行了研究。结果表明,纳米级CaCO₃能进一步改善PVC/ACR共混合金的冲击性能;其加工流变性能不仅没有降低,而且略有提高.     

TPU与CPE、PVC共混体系的研究

采用机械共混的方法,将CPE、PVC与TPU熔融共混.研究了TPU/CPE及TPU/CPE/PVC共混体系.对其力学性能、流变性能及耐油性能进行了测试及分析.结果表明CPE及CPE/PVC的加入可改善TPU的加工性能并降低其成本.     

PVC/EVA/ABS共混物结构对其加工行为及性能的影响

研究了乙烯-醋酸乙烯酯共聚物(EVA)和ABS对PVC的改性作用及其机理,探讨了共混条件、改性剂组成对共混物力学性能和热性能的影响。得到了PVC/EVA/ABS三元共混物的最佳共混时间和温度;共混物的常温冲击强度有提高,而拉伸强度变化不大;耐低温性良好,热稳定性优于PVC。并借助扫描电镜、透射电镜获得了清晰的共混物多相网状结构照片,对共混物结构性能进行了探讨。在哈克流变仪上,研究了共混体系的流变性,EVA和ABS加入PVC中,可改善PVC的加工性能。     

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     

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     

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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