扩链剂对水性聚氨酯乳液的影响

通过自乳化聚合引入低分子扩链剂制得具有嵌段结构的阴离子型水性聚氨酯乳液。研究了不同扩链剂及其用量对聚醚型和聚酯型聚氨酯乳液的影响。结果表明,以乙二醇为扩链剂制得的聚氨酯乳液稳定性较好,且所得的聚酯型聚氨酯涂膜的力学性能也较好,但耐水性较差。扩链剂的最佳用量为2.05%(质量分数)左右。     

新型水性聚氨酯乳液的合成及其性能影响因素的研究

采用预聚法合成了一新型的水性聚氨酯乳液,研究了配方中异氰酸酯基和羟基的物质的量的比(-NCO/-OH)、反应温度、羧基含量对水性聚氨酯的粘度、粒径和吸水率等性能的影响。表明,随着-NCO/-OH比的增大,粘度下降,粒径增加,吸水率下降;预聚反应温度越高,越快达到异氰酸酯基的理论值,但是温度越高越易发生副反应;随着羧基含量的增加,粘度升高,粒径起初下降,最终趋于平衡,吸水率升高。     

水性聚氨酯类湿摩擦牢度提升剂的合成与应用研究

以聚醚多元醇、异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)、N-甲基二乙醇胺、二乙烯三胺为主要原料,合成了水性聚氨酯湿摩擦牢度提升剂,并对其合成条件影响因素进行了探讨.实验结果表明:合成水性聚氨酯提升剂的最佳的预聚反应温度为75℃,R值(-NCO/-OH的物质的量比)为2.5,亲水性扩链剂的用量为3.92％.用此提升剂对染色棉布进行耐湿摩擦牢度测试,得出了最佳的整理工艺,结果表明:该提升剂能够有效地提高染色织物的湿摩擦深度.     

水性双组分聚氨酯柔感涂料的制备及性能

以自制聚酯多元醇、二异氰酸酯为原料分别合成含羟基端水性聚氨酯及水性聚氨酯,并以亲水性脂肪族聚异氰酸酯为固化剂,添加适量助剂配制水性双组分聚氨酯柔感涂料.考察了聚酯多元醇的相对分子质量、二羟基丙酸(DMPA)的用量、-OH/-NCO比例等与涂料的稳定性、铅笔硬度、附着力、柔韧性、耐水性、耐溶剂性、耐化学品性、耐刮伤性以及耐化妆品性之间的关系.研究结果发现:合成水性聚氨酯分散体所用的聚酯多元醇的相对分子质量为2 000,DMPA质量分数为6%,合成羟基端水性聚氨酯分散体中-OH/-NCO=1.6,固化过程中-NCO/-OH=1.5～1.6时,涂料的综合性能最好.     

紫外光固化水性聚氨酯-丙烯酸酯乳液性能的研究

选用异佛尔酮二异氰酸酯(IPDI)、聚酯二元醇、二羟甲基丙酸(DMPA)、甲基丙烯酸-β-羟乙酯(HEMA)等为原料,采用阴离子自乳化法制备了紫外光(UV)固化水性聚氨酯-丙烯酸酯乳液.考察了n(-NCO)/n(-OH)、DMPA及HEMA质量分数对乳液性能的影响.结果表明,n(-NCO)/n(-OH)为1.4～1.5,DMPA的质量分数为4.5%时乳液性能最好.同时,HEMA质量分数越高,乳液黏度越小.     

水性聚氨酯-丙烯酸酯复合乳液的合成与表征

为开发高性能且环保的丙烯酸酯改性水性聚氨酯乳液,以甲苯二异氰酸酯、聚醚二元醇、二羟甲基丙酸（DMPA）和甲基丙烯酸甲酯为主要原料,采用原位乳液聚合法,先制得水性聚氨酯预聚物／乙烯基单体混合物,然后加入引发剂,经自由基乳液聚合得到聚氨酯一丙烯酸酯（PUA）复合乳液,并对影响复合乳液性能的因素进行了探讨．研究发现,PUA复合乳液的性能及外观与-NCO／-OH比（物质的量比,下同）、二羟甲基丙酸（DMPA）含量以及中和度等密切相关．当n（-NCO）：n（-OH）=1．3～1．4,-COOH质量分数在2．6％左右．中和度为90％～100％时,所得PUA复合乳液的外观好、性能佳．     

阳离子水性聚氨酯表面施胶剂的制备及其应用

以甲苯二异氰酸酯（TDI）、聚酯二元醇、1,4-丁二醇和亲水扩链剂为原料,采用“内乳化法”制备阳离子水性聚氨酯乳液,讨论亲水扩链剂的种类和用量、中和方式、扩链温度等对聚氨酯乳液及其涂膜性能的影响,并将制得的聚氨酯乳液用于瓦楞原纸、涂布原纸的表面施胶．结果表明：其施胶效果良好,对纸页的相关性能具有明显的改善作用．     

高强度聚氨酯乳液的合成与性能研究

采用甲苯二异氰酸酯（TDI）、聚合物多元醇和二羟甲基丙酸（DMPA）反应制得聚氨酯乳液,讨论了不同的聚合物多元醇,-NCO与-OH摩尔比值,三羟甲基丙烷（TMP）和DMPA对乳液胶膜力学性能的影响,研究结果表明,当采用聚酯二元醇ODX-218,-NCO与-OH的摩尔比值为1.5,TMP和DMPA含量为2.0%和7.0%时,可以得到胶膜力学性能好的聚氨酯乳液。     

新型水性聚氨酯乳液的合成及其性能影响因素的研究

采用预聚法合成了一新型的水性聚氨酯乳液，研究了配方中异氰酸酯基和羟基的物质的量的比（-NCO／-OH）、反应温度、羧基含量对水性聚氨酯的粘度、粒径和吸水率等性能的影响。表明，随着-NCO／-OH比的增大，粘度下降，粒径增加，吸水率下降；预聚反应温度越高，越快达到异氰酸酯基的理论值，但是温度越高越易发生副反应；随着羧基含量的增加，粘度升高，粒径起初下降，最终趋于平衡，吸水率升高。     

水性聚氨酯乳液表观性质的研究

以异佛尔酮二异氰酸酯（IPDI）、聚酯多元醇、2,2-二羟甲基丁酸（DMBA）为主要原料,经自乳化法制备出高固含量的IPDI型水性聚氨酯乳液.研究了乳化温度、小分子二元醇、扩链剂等不同因素对乳液黏度和胶粒粒径、胶粒形貌的影响,结果表明：当DM-BA质量分数为5.5％、乳化温度为2℃时,制备的乳液固含量高达45％,乳液黏度较低,稳定性好;加入乙基丁基丙二醇（BEPD）或扩链剂异佛尔酮二胺（IPDA）有利于调节分子间相互作用力而使粒径变小,乳液黏度变低;利用非离子型亲水扩链剂三羟甲基丙烷聚乙二醇单甲醚（TMPEG）与DMBA的协同效应有利于乳液稳定性的提高.     

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