用DSC法研究麦秸人造板用胶的热反应特征

用差示扫描量热示（ＤＳＣ）研究了麦秸人造板用胶（异氰酸酯（ＭＤＩ）、脲醛树脂（ＵＦ）和改性ＵＦ树脂）以及它们与麦秸之间的热反应特征,结果表明：ＭＤＩ自身的热反应特征平稳。在被测的温度范围内,基本无放热及吸热现象发生;ＭＤＩ和水共同加热时,可以产生放热及吸热反应;改性ＵＦ树脂与未改性ＵＦ树脂相比,吸热反应提前发生,总吸热量减少。     

乙烯基共聚物与金属复合材料界面结构研究

利用反射吸收红外光谱法(RAIR)研究了两种乙烯基共聚物与金属(铜,铁)复合体系界面的化学结构特征.研究表明,乙烯-醋酸乙烯共聚物(EVA)中羰基峰在EVA与金属作用时分裂产生双峰,自由羰基峰与金属发生络合反应而向低波数方向移动;同时证明EVA中羰基垂直作用于金属表面.对乙烯-甲基丙烯酸共聚物(EMAA)与金属复合界面的研究表明,在EMAA与铁复合体系的界面层中有络合物生成,而EMAA与铜的体系有羧酸盐离子产生.     

PVC／PU共混物的动态力学性能和热稳定性研究

以邻幕二甲酸二辛酯（DOP）为增塑剂来增塑聚氯乙烯（PVC），采用熔融共混法制备了聚氯乙烯（PVC）和聚氨醋（PU）共混物。并利用动态力学分析（DMA）和热失重分析（TGA）研究了共混物的相容性、动态力学性能和热稳定性。DMA结果表明，随着PVC／DOP共混物中DOP含量增加，玻璃化转变温度Tg向低温偏移，且tanδ峰值逐渐增大。加入PU后，tanδ-T曲线都只存在一个峰，说明两者有较好的相容性。TGA结果显示，（PVC＋DOP）／PU混合材料中PU的加入降低了共混物的热失重速率，改善了材料的热稳定性。     

聚烯烃/水镁石粉复合体系的性能

采用线性低密度聚乙烯/乙烯-醋酸乙烯共聚物(LLDPE/EVA)作为基体树脂,水镁石粉为主阻燃剂,研究了水镁石粉对LLDPE/EVA体系的燃烧性能、力学性能、热分解性能的影响.结果表明,水镁石粉对LLDPE/EVA(质量配比为80/20)体系有很好的阻燃作用,阻燃性能随着水镁石粉添加量的增加而提高,但较高的水镁石粉添加量会引起力学性能的显著下降.当水镁石粉添加量增加到120份时,相应复合体系的总失重下降到53.4%,树脂炭化率上升到63.4%,阻燃性能达到FH-1级.     

湖沥青改性沥青及沥青混合料低温性能研究

采用延度试验和弯曲梁流变试验对不同TLA掺量改性沥青的低温性能进行研究,并利用差热扫描(DSC)研究不同TLA掺量的改性沥青组分在温度变化过程中的状态变化,最后通过低温小梁弯曲试验对混合料的低温性能进行评价.结果表明:随着TLA的掺量增加,湖沥青改性沥青的延度值逐渐减小、蠕变劲度S值和玻璃化转变温度Tg逐渐增大,TLA改性沥青的低温抗开裂能力变差,掺加35%TLA的改性沥青混合料的破坏应变与SBS改性沥青混合料破坏应变值相差不大;三种TLA掺量的湖沥青改性沥青的吸热峰都出现在125~145℃之间,加入TLA后,吸热峰位置的变化说明沥青组分的存在方式、数量以及相态转化方式发生了变化.     

SMA共聚物玻璃化转变温度测定条件的优化

本文利用差示扫描量热法（DSC）研究了气氛、升温速率、试样量和载气流速对苯乙烯-马来酸酐共聚物（SMA）玻璃化转变温度的影响,并用优化后的条件考察了上海石油化工研究院自制SMA样品的玻璃化转变温度。实验结果表明,在试样量10 mg左右、氮气流速40 mL/min、升温速率20 ℃/min的优化条件下,测定结果良好,经验证,DSC与动态机械热分析(DMTA)所测得的Tg基本一致,表明优化后的条件很适合SMA玻璃化转变温度的测定,此结果有助于SMA的生产和应用。     

苯酚型硼氮配位酚醛树脂的热性能与热降解动力学

用多聚甲醛法合成了苯酚型硼氮配位酚醛树脂,1H NMR和FTIR证明了其结构,用动态力学谱仪测定了玻璃化转变温度(Tg)与固化程度的关系,用热重法(TGA)分析了硼氮配位酚醛树脂的热分解动力学.结果表明树脂的玻璃化转变温度超过200℃,并随固化反应程度增加而提高,热分解过程为多阶段分解,且均符合一级动力学,热分解活化能随分解程度提高而增加.     

聚醋酸乙烯酯熔体的力学谱

利用液态内耗仪研究了聚醋酸乙烯酯(PVAc)在其玻璃化转变温度（Tg）及其以上温度区域的力学弛豫行为.结果表明：PVAc内耗与温度的关系曲线上存在α和α′ 2个弛豫型内耗峰，α峰与PVAc的玻璃化转变有关，α′峰则对应于一种液/液转变，且两者的弛豫时间均满足Vogel Fulcher Tamman关系；在PVAc熔体内耗与频率的关系曲线上，交叉温度TB≈387 K处的α′峰的弛豫时间、弛豫强度和分布参数均出现了一个转折，这是由于降温过程中TB至Tg之间分子耦合作用显著增强的结果.     

芴基苯并噁嗪单体的合成及热性能研究

以双酚芴、环己胺和甲醛为原料,采用混合溶剂法合成了一种新型双官能度芴基苯并噁嗪单体,利用FTIR,1H NMR和13C NMR对产物结构进行了表征,以差式扫描量热仪(DSC)研究了芴基苯并噁嗪单体的固化行为,通过DSC和热重(TGA)分析了聚苯并噁嗪的热性能.结果表明,芴基聚苯并噁嗪树脂呈现出典型的热开环固化特征,放热峰顶温度为251℃,玻璃化转变温度Tg为189.4℃,初始热分解温度(热失重5%)达329℃,800℃时的残碳率达到31%.     

PET玻璃化转变温度处双重吸热峰的研究

在室温下长时间存放以及再拉伸,聚对苯二甲酸乙二醇酯经示差扫描量热分析(DSC),其热谱在玻璃化转变区域出现单一的或双重的附加吸热峰。单一吸热峰和双峰中前吸热峰与样品热历史有关,反映有序非晶区的存在,双峰中后吸热峰与拉伸历史有关,可能反应介晶结构存在。     

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     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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