聚甲基丙烯酸甲酯-丙烯酰胺/SiO2/TiO2的制备及表征

用溶胶-凝胶法以乙烯基三乙氧基硅烷为偶联荆合成有机聚合物与TiO2相间有共价键存在的聚甲基丙烯酸甲酯-丙烯酰胺P(MMA-AAM)/SiO2/TiO2杂化材料.用FT-IR、TG/DSC、SEM对产物进行了表征,结果表明:FT-IR可看出SiO2和TiO2在杂化材料中形成Ti-O-Si网络结构,TiO2在杂化材料中均匀分布且杂化材料的热分解温度比纯共聚物提高50℃.     

聚酰亚胺/二氧化硅杂化膜和复合膜的制备与结构研究

采用溶胶-凝胶法和二氧化硅粒子掺杂共混法分别制备了聚酰亚胺/SiO2杂化膜和纳米复合膜.采用红外分光光度计(FTIR)、热重分析仪(TGA)和透射电镜(TEM)表征了所制备膜的结构微观形态和热性能并进行分析对比,结果表明在杂化膜中SiO2在聚酰亚胺基体中可以形成分子级分散,复合膜表现出较强的吸湿性使其热分解温度较低.研究认为,采用溶胶-凝胶法制备聚酰亚胺/SiO2介电材料更为合理.     

硼酚醛/桐油/纳米SiO2杂化材料的制备及其红外表征

利用原位法制备了硼酚醛／桐油／纳米SiO2杂化材料,并用红外光谱进行结构表征,通过分析谱图中羰基、硅氧键、双键等的变化,研究了反应条件及投料比对杂化材料结构的影响。结果表明硼酚醛／桐油／纳米SiO2杂化材料具有优异的对热稳定性,能获得较高的碳的残留率,且具有良好的柔韧性。     

纳米SiO2-Al2O3聚酰亚胺杂化薄膜的制备及表征

采用溶胶凝胶法制备了二氧化硅及三氧化二铝溶胶,将其掺入聚酰胺酸基体中,得到SiO2-Al2O3聚酰亚胺杂化薄膜,对膜的结构性能进行了研究和表征.结果表明,薄膜材料中SiO2和Al2O3粒子分散均匀,与有机相存在键合,材料热分解温度有所提高.     

纳米SiO_2/聚合物杂化乳液制备与成膜进展

纳米SiO2/聚合物杂化乳液是重要的有机/无机杂化材料之一,它兼具有机和无机材料的优点。综述了纳米SiO2/聚合物杂化乳液的制备方法,包括共混法、Sol-gel法和原位聚合法。探讨了纳米SiO2/聚合物杂化乳液成膜机理进展。指出纳米SiO2/聚合物杂化乳液是功能涂料的发展方向之一。     

溶胶-凝胶法制备HEC/SiO2杂化材料的工艺研究

以羟乙基纤维素(HEC)、正硅酸乙酯(TEOS)为原料,采用溶胶-凝胶技术合成了HEC/SiO2有机-无机杂化材料.通过探讨水硅比、HEC含量、溶剂量、干燥控制化学添加剂用量、温度等工艺因素对凝胶化过程,特别是材料干燥体积收缩的影响,得出在本实验条件下合成HEC/SiO2有机-无机杂化材料的优化工艺条件.利用红外吸收光谱、紫外-可见光透射光谱以及扫描电子显微镜等测试手段对合成的HEC/SiO2有机-无机杂化材料进行表征.结果表明,HEC作为有机分散相已经均匀地分散到SiO2基相中,制备的HEC/SiO2有机-无机杂化材料透明,无分相,并可能形成了新的化学键.     

RuO2- SiO2活性材料的研究与高性能超电容电极的表征

采用热分解法制备了RuO2 - SiO2/Ti活性材料,通过XRD、循环伏安和恒流充放电等测试方法,研究了涂层电极的活性及电容性能.分析表明,240℃烧结的涂层为不稳定的非晶态结构;260℃涂层主体为非晶态结构,但已经开始晶化转变;280℃已出现了金红石晶粒,晶粒极为细小;300℃以上烧结时,涂层中的晶粒明显长大;45...     

TiO_2/SiO_2纳米粉体的相变及其红外性能

以溶胶-凝胶法制备纳米TiO2/SiO2复合粉体,用XRD,AFM,IR等方法进行了表征,研究了纳米TiO2/SiO2复合材料的晶型转变温度变化和红外吸收性能.结果表明,所制备的纳米TiO2/SiO2复合材料与单一组分的纳米TiO2,SiO2相比,晶型转变温度有提高的趋势,并且该复合材料在1700～400cm-1范围内有较强的红外吸收.     

碳/酚醛复合材料体积烧蚀行为的数值模拟

为了准确掌握碳/酚醛防热复合材料的烧蚀特性和烧蚀机理,基于质量和能量守恒、材料热分解以及物性的计算方程,应用数值模拟方法计算了碳/酚醛复合材料的热响应和体积烧蚀行为.计算结果表明:烧蚀过程中碳/酚醛复合材料具有不均匀的温度场分布,在厚度方向上最大温差达到了634 K,并且加热面上基体温度比纤维温度高出了175 K;酚醛基体的平均密度几乎呈线性衰减,40 s时平均密度降低了37.8%;烧蚀过程中酚醛基体具有较大的质量损失,40 s时质量损失了0.31 g,是20 s时的2.4倍.     

无溶剂前端聚合法制备聚乙烯吡咯烷酮/SiO2 杂化材料

通过无溶剂前端聚合法制备聚乙烯吡咯烷酮(PVP)/SiO2杂化材料.实验结果表明:聚合前端是以恒定的速度移动,为纯前端聚合的发生提供了有力证据.随着引发剂2,2′-偶氮二异丁腈(AIBN)质量分数从0.15%增大到0.3%,前端聚合反应速率随之从0.3cm/min上升到0.7cm/min,前端最高温度tmax也从120℃上升到130℃.分别用傅里叶红外光谱(FT-IR)、场发射扫描电镜(FE-SEM)、热质量分析TGA等表征手段对聚乙烯吡咯烷酮/SiO2杂化材料进行测试分析.结果表明:通过无溶剂前端聚合,PVP成功地接枝在功能化SiO2的表面,形成了类似核壳结构的有机/无机杂化材料.     

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