水性紫外光固化体系中光固化速度的影响因素

以甲苯-2,4-二异氰酸酯、聚己二酸丁二醇酯二醇、二羟甲基丙酸、丙烯酸-β-羟乙酯为原料合成了光敏性树脂.经三乙胺中和后可以得到稳定的自乳化体系.考察了光引发剂种类、用量、干燥条件、中和度、中和剂种类及结构对光固化速度的影响.结果表明,本体系优选光引发剂Irgacure1000的质量分数为3%时固化速度最快;干燥条件对光固化速度有很大的影响;随着中和度的提高,固化速度下降;用NaOH作为中和剂时,后期固化速度快于用三乙胺;聚合物结构对固化速度有一定的影响,随着PBA/DMPA和HEA/DMPA比例的提高,固化速度加快.     

紫外光固化竹木亚光涂料的研制

研究了齐聚物、消光剂、光引发剂和活性稀释剂的种类及含量,对紫外光(UV)固化竹木亚光涂料的固化速度、光泽度和硬度的影响.通过对大量实验的分析和探讨,得出了最佳涂料配方,为竹木亚光涂料的应用提供了理论与实践基础.     

影响UV固化光纤着色涂料固化速率的因素

本文从光引发剂、涂膜厚度、单体、颜料几个方面研究了影响红、黄、兰三种体系紫外光固化涂料（ UVCC）的固化速率的因素．当光引发剂含量为最佳值时，固化速率可达最大值．不同颜料对固化速率的影响不同，随着颜料含量的增加，固化速率都降低．膜厚对固化速率的影响很大，膜越厚，固化速率越低．一定含量的多官能度单体，可提高 UVCC的固化速率．     

光固化3D打印光敏树脂的临界能量和固化深度影响因素

不同的3D打印光敏树脂,在同一3D打印机下进行光固化,其固化性能有所差异。采用临界曝光量和固化深度2个特性参数来表征光固化树脂的光敏性,探讨了临界曝光量和固化深度之间的数学关系,研究了临界曝光量和固化深度的测定方法,测定了光强和树脂的颜色对树脂固化的影响。在一定条件下,固化深度通常随光照强度的增加而增加,临界曝光量也随光照强度的增加而增加;浅色比深色树脂固化深度高,且所需临界曝光量更高。同时,固化深度随着光引发剂的浓度增加而降低;临界曝光量随着光引发剂浓度的增加先降低,后趋于平缓。     

紫外固化中光敏促进剂对固化速度的影响

主要研究在紫外固化过程中氯化亚锡光敏促进剂对凝胶固化速度的影响.从光敏剂的反应机理上分析和氯化亚锡的紫外吸收光谱测试研究表明:氯化亚锡促进剂在反应中起到了敏化剂的作用;在光引发剂中加入适量的光敏促进剂(SnCl2)对体系凝胶固化速度有很大的提高.     

水性紫外光固化聚氨酯丙烯酸酯树脂的合成

采用甲苯二异氰酸酯、聚丙二醇、二羟甲基丙酸和丙烯酸羟乙酯合成了水性紫外光固化聚氨酯丙烯酸酯树脂,并用高支化聚酯对其进行了改性,研究分析了影响树脂水溶性和感光性的各种因素。结果表明,树脂亲水性与亲水基团含量呈正比;以819-DW为光引发剂,质量分数为3%时,涂膜光固化速度最佳;经高支化聚酯改性后的涂膜的综合性能有了较大的提高,质量分数为10%时,涂膜的综合性能最佳。     

紫外光固化环氧大豆油树脂的合成和表征

研究了可作为紫外光固化涂料和油墨等产品的基体树脂的改性环氧大豆油树脂的合成及表征.利用环氧大豆油的环氧环的化学活性,先后与丙烯酸和马来酸酐进行反应,分别合成了油溶性环氧大豆油丙烯酸酯(AESO)和水溶性的马来酸改性环氧大豆油树脂(MAESO).并用红外和核磁对两种产物的结构进行了表征.添加紫外光引发剂后,两种产物在紫外光照射下均可快速固化.合成AESO最佳条件为环氧大豆油:丙烯酸=1.2:1(摩尔比),催化剂三苯基膦的用量为总质量的1%,反应温度为120℃;合成MAESO最佳条件为AESO:马来酸酐=4:1(摩尔比),催化剂钛酸正丁酯用量为1%,反应温度90℃.     

UV自由基固化和阳离子固化涂层的比较研究

对 U V自由基固化和阳离子固化两种机理进行了对照试验 .考察了温度和 O2 对固化速度的影响 ,涂层性能及它们作为 UV固化涂料、油墨的优缺点 ,并从理论上进行了分析 .U V自由基固化和阳离子固化的固化速度随温度的升高而加快 ,并且自由基的固化速度大于阳离子固化速度 .自由基固化体积收缩大 ,附着力差 ;阳离子固化体积收缩小 ,附着力优异 .氧对自由基固化有显著的阻聚作用 ,而对阳离子固化没有阻聚效应 .此外 ,阳离子固化存在“暗反应”,当移走 UV光源后 ,仍会发生固化反应     

光引发剂对光敏银浆紫外光固化性能的影响

研究了用于光敏银浆的4种光引发剂:1-羟基-环已基-苯基甲酮、1-对甲硫基苯基-2-甲基-2-吗啉基-1-丙酮、1-对吗啉苯基-2-二甲氨基-2-苄基-1-丁酮和2-异丙基硫杂蒽酮.在相同的光敏银浆体系中,添加不同引发剂,进行紫外照射固化、显影、烧结,得到电极图形.通过扫描电镜和铅笔硬度法比较了单引发体系和复合引发体系对固化性能的影响,其中单引发体系引发剂用量为1%～7%,复合引发体系中2种单引发剂质量比为1∶7～2∶1,用量为1%～8%.实验结果表明,复合引发体系引发效率高于单引发体系,尤以1-对甲硫基苯基-2-甲基-2-吗啉基-1-丙酮与2-异丙基硫杂蒽酮复合质量比为4∶1～3∶1时光引发效果最好; 当体系中复合引发剂含量为5%时,固化效果最好,固化时间选择以30 s为佳.     

扩链剂对UV固化聚氨酯性能的影响

以聚己二酸一缩二乙二醇酯-2000为软段,不同二元醇扩链剂和异佛尔酮二异氰酸酯(IPDI)为硬段,丙烯酸羟乙酯(HEA)封端,采用预聚体法合成UV固化聚氨酯.分析了不同二元醇扩链剂的相对动力学活性;通过红外光谱表征了光固化聚氨酯树脂的结构,研究了不同的二元醇扩链剂对光固化膜力学性能、耐热性能和使用性能的影响.结果表明,反应温度80℃,乙二醇(EG)与苯基异氰酸酯(PI)的反应速率最快,1,2-丙二醇(1,2-PEG)与PI的反应速率最慢;以1,4-环己烷二甲醇(CHDM)为扩链剂的聚氨酯膜力学性能和耐热性最好.     

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.     

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     

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