双酚F环硫/环氧树脂/胺体系固化反应及其交联网络的研究

合成了双酚F环氧/环硫树脂，采用元素分析、红外光谱分析和核磁共振光谱分析确定了合成树脂的结构,对比研究了环硫基团/环氧基团为0/100、15/85和50/50（质量比）的双酚F环硫/环氧树脂与脂环胺DMDC固化剂体系的固化行为。通过差示扫描量热仪（DSC）、动态力学热分析仪（DMTA）等手段研究了固化剂配比对体系固化程度、固化物的模量和玻璃化转变温度的影响，结果显示：当环硫基团质量分数从0分别增加到15%和50%时，环硫/环氧树脂/胺体系不仅固化速度加快，且固化剂用量相应减少约15%和50%，说明胺基与环硫基团开环反应形成的—SH或—S-可作为固化剂进一步与环氧基团和环硫基团进行开环反应；另一方面，固化物的模量和玻璃化转变温度有所提高，说明环硫树脂固化物交联网络更密集，也证明了环硫/环氧树脂的固化反应行为与环氧树脂存在不同。     

含磷芳胺/环氧树脂体系固化反应的DSC研究

采用ＤＳＣ方法研究了含磷芳胺／Ｅ－５１环氧树脂体系的固化反应,测定了反应表现活化能。结果表明,含磷芳胺固化剂的反应活性高于对应的芳胺固化剂,与脂肪胺固化剂的反应活性相近,含磷芳胺／Ｅ－５１体系的固化反应活化能为６９．５０￣７７．７５ｋＪ／ｍｏｌ。此外,ＤＳＣ实验表明含磷芳胺对芳胺ＤＤＭ／Ｅ－５１体系有促进固化作用。     

两种DOPO阻燃环氧树脂固化剂的室温合成及性能研究

无卤反应型多元素协同是环氧树脂阻燃研究的热点,本文室温合成了上述功能的活性DOPO衍生物DOPO-M和DOPO-T。它们作为固化剂,分别与4,4′-二氨基二苯甲烷混合,再与等当量环氧树脂E51固化得到阻燃元素含量可控的环氧体系。使用NMR证明了DOPO衍生物结构,使用红外跟踪其固化过程,继而使用DMTA、TGA和LOI测试分别研究了DOPO衍生物引入量、结构区别对环氧树脂热力学性能、耐热性能及阻燃性能的控制趋势。结果表明,1)阻燃环氧体系都为均相体系;2)阻燃环氧体系的耐热性能及阻燃性能均得到显著提升;3)DOPO-M比DOPO-T在提升阻燃环氧体系的耐热性能及阻燃性能上更有优势。     

两种DOPO阻燃环氧树脂固化剂的室温合成及性能

无卤反应型多元素协同是环氧树脂阻燃研究的热点,室温合成了上述功能的活性DOPO衍生物DOPO-M和DOPOT。它们作为固化剂,分别与4,4'-二氨基二苯甲烷混合,再与等当量环氧树脂E51固化得到阻燃元素含量可控的环氧体系。使用NMR证明了DOPO衍生物结构,使用红外跟踪其固化过程,继而使用DMTA、TGA和LOI测试分别研究了DOPO衍生物引入量、结构区别对环氧树脂热力学性能、耐热性能及阻燃性能的控制趋势。结果表明:(1)阻燃环氧体系都为均相体系;(2)阻燃环氧体系的耐热性能及阻燃性能均得到显著提升;(3)DOPO-M比DOPO-T在提升阻燃环氧体系的耐热性能及阻燃性能上更有优势。     

水性环氧树脂涂膜固化的FTIR法

采用傅立叶变换红外光谱仪研究了水性环氧树脂涂膜的固化过程,得到不同固化温度下交联固化程度随时问的变化规律:水性环氧涂膜在固化前期属于动力学控制阶段,固化速率较高,固化程度随时间增加较快;固化后期属于扩散控制阶段,固化反应程度随时间的延长而增加缓慢.结果表明:此水性环氧树脂涂料体系的固化反应表观活化能为56.082 kJ/mol,室温下具有较快的固化反应速度.     

水性环氧丙烯酸接枝共聚物的合成及固化

环氧树脂与丙烯酸类单体接枝共聚是制备水性环氧树脂的一条重要途径.本文作者研究了多元接枝水性环氧树脂的合成,及其与固化剂双氰胺的固化工艺.讨论了单体配比、接枝反应温度、反应时间等因素对水性环氧乳液接枝率的影响,确定了较佳的工艺条件,通过红外光谱分析证实了丙烯酸接枝环氧共聚物的结构,并考察了漆膜的固化条件.所得涂膜附着力、柔韧性、硬度很好,能达到溶剂型环氧树脂防腐蚀涂料水平.     

固化剂对环氧沥青力学性能和相态结构的影响研究

采用基质沥青、增容剂、复配的羧酸固化剂和环氧树脂共混制备了热固性环氧沥青材料,通过力学性能测试、DMA、荧光显微镜及SEM照片分析研究了复配固化剂对环氧沥青固化体系力学性能和相态结构的影响.结果表明,在癸二酸中复配8g甲基四氢苯酐(MeTHPA)和改性桐油酸酐(TOA),拉伸强度由1.94MPa增加至2.36MPa和2.26MPa,25℃时针入度由31.8降低为10.1和16.0,Tg由25℃增加至54℃和41℃,tanδ>0.3的温度区间更宽,说明复配固化剂可以与环氧树脂形成交联密度更高、刚性更强的网络结构,更有效的提高环氧沥青的拉伸强度和高温阻尼特征;沥青在环氧树脂中的分散粒径和分布间距变得不均匀,但固化体系仍为沥青为分散相、环氧树脂为连续相的海岛状两相结构.     

含磷含氮酚醛树脂的合成与性能

以含磷单体、三聚氰胺、苯酚和甲醛为原料, 合成了一种含磷含氮酚醛树脂(NP-PF).将NP-PF与F51环氧树脂复配并固化, 并对其固化特征进行了研究, 同时考察了固化物的耐热性能和阻燃性能. 研究结果表明: 高含量的NP-PF能够提高NP-PF/F51体系的固化速率;NP-PF/F51固化物具有良好的耐热性能; 在NP-PF/F51固化体系中加入少量Al(OH)₃, 能够达到UL94V-0级阻燃的效果.     

有机硅改性水性环氧固化剂固化行为及固化膜热性能

用三乙烯四胺与环氧树脂在丙二醇甲醚中反应制得环氧树脂-三乙烯四胺加成物,经脂肪族缩水甘油醚/γ-缩水甘油醚氧丙基三甲氧基硅烷(GPTMS)对加成物封端,加酸中和及加水分散制得水性环氧固化剂,用傅立叶红外对聚合产物进行结构表征,研究了有机硅烷用量对固化剂的固化行为及固化膜热性能的影响.结果表明:GPTMS的加入使固化剂的固化起始温度及固化反应表观活化能降低,固化反应速率增加,固化膜的热稳定性提高.GPTMS的摩尔分数控制在3%~5%为宜.     

玻璃钢缠绕气瓶用环氧树脂固化动力学研究

制备了以环氧树脂为基体,甲基六氢苯酐为固化剂,咪唑为促进剂的环氧树脂体系。采用非等温差示扫描法(DSC)研究了环氧树脂/甲基六氢苯酐体系的固化过程,得出了升温速率对固化体系DSC曲线的影响。引用Kissinger理论,确定了固化反应的动力学参数以及固化反应动力学模型。     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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