聚乙烯醇缩丁醛—接枝丙烯酰胺的合成及生物医学性能

聚乙烯醇缩丁醛—接枝—丙烯酰胺共聚物已采用硝酸铈铵/硝酸引发体系于水悬浮液中在30℃合成,接枝长度和每个聚乙烯醇缩丁醛分子上支链的数几分别确定为(?)n3-6×10~4和0.1-0.3。测定了反应时间和铈离子浓度对接枝率,接枝长度和支链数目的影响。亦讨论了其他反应参数的影响,并研究了此聚合物的吸水率,对牛血清白蛋白的粘附及血液相容悱。结果表明此共聚物当接枝率为15—25%而平均接枝链长度((?)n)大于4×10~4其血液相容性良好。     

接枝变性淀粉浆料──接枝支链的分子结构设计分析及合成路线

本文从聚合物分子设计的基本思想出发，以纺织浆料材料的几个主要性能要求为依据，首次定性分析了接枝变性淀粉浆料接枝支链的分子结构，归纳出接枝支链的分子结构模型，并提出了合成路线．     

聚丙烯酸酯接枝聚氨酯共聚物合成及应用

确定了首先合成出带有异氰酸酯端基的聚氨酯预聚体支链部分，然后在聚丙烯酸酯主链上引入带有活泼氢的单体，通过异氰酸酯基与羟基反应将支链接枝到主链上的合成路线，制备了聚丙烯酸酯接枝聚氨酯共聚物溶液，并利用紫外吸收光谱法确定了产物的接枝共聚结构。将所合成了接枝共聚物溶液用于织物涂层整理，得到了具有优良性能的防水透湿涂层织物。     

新型甲基丙烯酸酯类接枝共聚物电解质的制备与表征

以甲氧基聚乙二醇甲基丙烯酸酯(MPEGM)和十六烷基聚乙二醇甲基丙烯酸酯(HPEGM)为单体,采用自由基溶液聚合法制备无规接枝共聚物P(MPEGM-HPEGM),并以此共聚物为基体混合锂盐(LiClO4)制备全固态聚合物电解质。用红外光谱(FT-IR)、差热分析(DSC)和交流阻抗(EIS)等方法对聚合物和聚合物电解质的性能进行研究。结果表明:MPEGM和HPEGM共聚生成P(MPEGM-HPEGM);聚合物中聚氧化乙烯(PEO)链段的运动能力得到提高,有利于离子传输;聚合物电解质膜的电化学稳定性窗口达到4.5 V;在30℃时,当MPEGM与HPEGM的质量比为80∶20,锂盐与氧化乙烯(EO)的摩尔比为1∶20时,聚合物电解质的离子电导率达到最高7.6×10-5S/cm;离子电导率随着温度的升高而迅速增加,电导率-温度的关系符合VTF方程。     

PLA大分子单体与NVP接枝共聚物的初步研究

以辛酸亚锡为催化剂,甲基丙烯酸羟乙酯(HEMA)为共引发剂引发消旋-丙交酯(D,L-LA)开环聚合,制备了末端双键功能化的聚乳酸大分子单体(PLA-HEMA);在此基础上,考察了大分子单体与N-乙烯基吡咯烷酮(NVP)的溶液自由基共聚合反应,并初步研究了共聚单体摩尔比和PLA支链长度对合成的两亲性接枝共聚物性能的影响.结果表明,随大分子单体投料量和PLA支链长度增大,共聚物膜的拉伸强度和模量增大,而亲水性有所下降.     

聚丙烯与马来酸酐反应挤出接枝共聚合的研究

本文采用反应挤出法,实现了小本体聚丙烯(PP)与马来酸酐(MAH)的接枝共聚合反应,用傅立叶变换红外光谱(FP-IR)证实了接枝反应的发生,并用化学分析的方法测定接枝物的接技率。研究发现在反映挤出过程中,小本体PP-MAH可以发生官能化反应,也可以是接枝上一定长度的MAH支链的反应,以及MAH的均聚合反应及小本体PP的降解反应,只是在不同的条件下不同的反应起主要作用,接技共聚物的接枝率强烈地依赖于所加单体MAH.引发剂的用量及挤出反应温度,确定了最佳共聚合工艺条件:单体MAH用量5-9g/100gpp。引发剂用量0.5—1.0g/100gpp,反应温度215—230℃。     

淀粉与丙烯酸接枝共聚物的结构表征

利用粘度法测定聚丙烯酸支链的平均分子量，红外光谱法分析接枝共聚物的结构。     

聚丙烯与三单体固相接枝物的等温结晶行为

采用固相接枝法合成聚丙烯(PP)与3种单体(马来酸酐、甲基丙烯酸甲酯和丙烯酸丁酯)的固相接枝物,利用傅立叶变换红外光谱研究接枝物的结构,通过差示扫描量热法和偏光显微镜研究固相接枝物的等温结晶行为,采用Avrami方程研究固相接枝物的等温结晶动力学.研究结果表明,接枝物的Avrami指数n和PP的相近,在0~3之间,说明接枝物存在混合式的成核生长方式.接枝支链充当异相成核剂,提高了成核速率,降低了结晶活化能;同时,接枝支链阻碍了PP基体的结晶进程,延长了接枝物完成结晶的时间.PP和PP接枝物结晶参数的拟合值与实验值基本一致,说明Avrami方程能有效地描述三单体固相接枝物的等温结晶行为.     

PE氯化原位接枝苯乙烯-丙烯腈共聚物

以高密度聚乙烯（HDPE）为原料,采用氯化原位接枝方法制备以氯化聚乙烯（CPE）为骨架、苯乙烯（St）为支链的接枝共聚物（记作CPE-cg-St）和以氯化聚乙烯（CPE）为骨架、苯乙烯和丙烯腈单体都为支链的接枝共聚物（记作CPE-cg-AS）.研究结果表明,氯化原位接枝可制备CPE-cg-AS,CPE-cg-St,且与CPE相比,接枝共聚物的相对分子质量增大,分布变窄,有较好的力学性能.在同样接枝率下,相同氯含量下,CPE-cg-AS,CPE-cg-St的拉伸强度较CPE分别增加了26.9％、8.9％.     

接枝变性淀粉浆料卓越上浆性能因果关系的初探

如果接枝变性淀粉浆料具有适当结构的接技支链，那么它对涤／棉混纺经纱应有着良好的上浆性能。然而，这种现象目前尚未见有明确的解释。本文通过与淀粉及非接枝变性淀粉浆料的比较，试图从结构与性能的角度分析探讨接枝变性淀粉浆料卓越上浆性能的因果关系，并认为它最适合于作为合成纤维／纤维素纤维混纺经纱的浆料使用     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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