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应用高效液相色谱技术,采用凝胶色谱柱和示差折光检测器,对合成的萘沥青树脂进行了分析,测出了产品的相对分子量为550~1 200,相对分子量分布D=1.15~1.25。与质谱法和粘度法相比,建立的高效凝胶渗透色谱(HPGPC)法更简便、快速和准确,误差小于±2%,对沥青树脂的合成工艺具有指导意义。 相似文献
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高性能双组份丙烯酸聚氨酯涂料的研制 总被引:4,自引:1,他引:3
本文研究了低成本,高性能羟基丙烯酸树脂的合成,并采用傅立叶变换红外光谱(FTIR)及凝胶渗透色谱(GPC)分析了丙烯酸树脂的结构和分子量分布,以此树脂为基础,采用六亚甲基二酸酯(HDI)缩二脲为固化剂,制得了高性能的双组份丙烯酸聚氨酯涂料。 相似文献
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炭材料是一种重要的功能和结构材料,能否保障炭材料制品质量的关键在于使用粘结剂性能的好坏,沥青树脂粘结剂因与炭素材料有良好的亲和性而倍受国内外学者的广泛关注.以中低温煤焦油沥青为原料,多聚甲醛为交联剂,对甲苯磺酸为催化剂合成沥青树脂.考察了合成条件对沥青树脂的软化点、结焦值和β树脂等指标的影响,采用FT-IR表征了沥青树脂的合成机理.研究结果表明,中低温煤焦油沥青与多聚甲醛发生了阳离子型缩聚反应,沥青树脂的软化点在136.2~177.3℃、结焦值在27.64%~38.05%、β树脂在22.79%~41.89%可以进行调控. 相似文献
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利用CHP-20多孔树脂凝胶色谱(日产),分离提纯了带磺酸基的乙烯砜型活性染料及其水解物和醇解物。采用离子对反相高效液相色谱对这些化合物进行了分离分析。(一)样品的纯化合成的四个化合物见表1。采用快速层析柱对化合物Ⅰ、Ⅱ、Ⅲ进行分离提纯。填料为日本产CHP-20多孔树脂。 相似文献
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为了研究哈法亚油田沥青质的沉积趋势,对哈法亚油田三种不同油藏原油进行四组分分离,利用胶体体系稳定性定量计算方法预测了沥青质的沉积趋势,并采用元素分析、红外光谱(FTIR)、凝胶渗透色谱(GPC)、核磁共振(1H-NMR)等分析手段对其沥青质分子结构进行了表征,探索了沥青质分子结构与沉积趋势的内在联系。研究结果表明:哈法亚油田原油沥青质有沉积的趋势,且样品A胶体不稳定指数较大,其沥青质较容易沉积。三种沥青质的结构参数存在差异,分子量、芳香度和芳香缩合度从样品A沥青质、样品B沥青质、样品C沥青质依次减少,而氢碳比(H/C比)依次增大。沥青质聚集体的稳定性与沥青质分子结构特征密切相关,H/C比值较低以及分子量、芳香度、芳香缩合度较高的样品A沥青质具有更大的稳定能,其沥青质沉淀的可能性也较大。 相似文献
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《吉林大学学报(理学版)》1983,(1)
高效凝胶色谱是最近几年发展起来的一种新的分析分离技术。由高效凝胶色谱填料填充的高效色谱柱是这一分离技术的核心。我校化学系研制了一种由苯乙烯与二乙烯基苯共聚的聚苯乙烯凝胶,其粒度为10μm左右。 用此凝胶装填的GPC高效柱子,理论板数可优于2万块/米,用柱长50cmGPC柱分析高聚物分子量及其分布,只需20分钟左右。 相似文献
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为了选取性能优良的浸渍纳米复合材料,利用凝胶渗透色谱仪对16种不同合成条件下的纳米复合材料样品进行实验,分别求得相对分子量和检测纳米复合材料质量指标.结果 表明,n(苯酚)∶ n(甲醛)∶ n(NaOH)∶ n(纳米SiO2)为1∶ 2.0∶ 0.1∶ 0.27,反应时间超过180min时,纳米复合材料的分散指数小,相对分子量均匀;相对分子量分布在200~400的占98.3%.树脂质量指标检测表明:ω(固体)为49.8%,ω(游离苯酚)为0.18%,ω(游离甲醛)为0.10%,ω(可被溴化物)为15.5%. 相似文献
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氨酯键和脲键对嵌段聚氨酯和嵌段聚脲性质影响的研究 总被引:2,自引:0,他引:2
用溶液聚合法合成了四种聚氨酯、聚脲模型化合物.并用凝胶渗透色谱,应力—应变,广角X射线衍射等手段检验了在相界面或在硬段微区,不同键对聚合物分子量、力学性质和聚合物形态的影响. 相似文献
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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. 相似文献
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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. 相似文献
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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。 相似文献
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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. 相似文献
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Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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- 相似文献
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Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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- 相似文献
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Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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 相似文献
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《上海师范大学学报(自然科学版)》2014,(5):550
<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 相似文献
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《吉林大学学报(理学版)》2014,(5):1105
<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has 相似文献