AFM对壳聚糖富集银离子的分形学研究

利用原子力显微镜(AFM)对壳聚糖吸附银离子进行研究，从形貌学的角度探测壳聚糖络合银离子的机理特性．主要方法是将溶液滴加在新解离的云母片上，应用原子力显微镜对自然风干后的样品在非接触模式下成像．AFM图像显示：壳聚糖分子和加过金属银离子的壳聚糖分子在聚集生长过程呈现为传统的具有分形特征的正态分布和奇异分布；由单一的壳聚糖分子形成的分形结构为“星”形结构，而加过银离子的壳聚糖分子形成的结构为“圆”形．产生这些图形差别的根本原因是由于生长界面的表面张力及其各向异性起了重要作用．这两种结构都具有典型的自相似性，且实验结果与计算机模拟的分形模式拟合得很好．     

纯水亚相二十二酸单分子膜循环曲线研究

利用近来提出的Vollardt方程和二维聚集的准化学平衡模型,研究了不同表面压下的二十二酸(简称BA)单分子膜循环等温(π-A)曲线,其理论计算结果与实验曲线相一致,随着循环曲线中选取表面压的增加,分子膜聚集过程中形成的聚集体单个分子面积(ω(n))减少,而聚集度(ε值)相应增加;另外考察了二十二酸单分子膜热力学性质和聚集作用,其热力学计算表明压缩和扩张曲线中聚集自由能(ΔG0)有较大改变;且从低表面压(9 mN/m)到高表面压(18 mN/m)聚集自由能(ΔG0)的改变量比高表面压(26 mN/m与35 mN/m)时要大.结果显示,压缩和扩张曲线在液相区出现明显的不重合,不重合区域的大小反映分子膜聚集程度的大小.     

EGCG分子印迹壳聚糖膜的制备及性能研究

利用分子印迹技术,以壳聚糖为功能基体,表没食子儿茶素没食子酸酯(EGCG)为模板分子,硫酸为交联剂,制备了EGCG分子印迹壳聚糖膜,并探讨了平衡吸附时间、pH值、温度及功能单体和模板分子的比例等因素对印迹膜吸附性能的影响.SEM和AFM测试结果表明印迹膜的表面形貌不同于非印迹膜;同时用红外光谱分析了印迹分子的洗脱情况.平衡结合法实验结果表明,印迹膜对EGCG具有较好的亲和性和选择性.Scatchard分析表明,印迹膜在识别EGCG的过程中存在1类结合位点,其平衡结合常数K为4.046,最大吸附量Qmax为49.52mg·g-1.     

壳聚糖-海藻酸钙微球荧光标记反应对微球膜强度影响的研究

以壳聚糖-海藻酸钙载药微球给药后的体内检测为研究背景,探讨不同反应条件下壳聚糖-海藻酸钙微球荧光标记反应对微球膜在模拟体液中的强度影响.以壳聚糖、海藻酸钠为微球制备载体材料,以异硫氰酸酯(FITC)为荧光标记物对微球进行荧光标记.采用标记了FITC的微球在模拟体液中的膨胀率来表征微球膜的相对强度.采用相对分子质量为50 000、脱乙酰度85%、荧光标记浓度0.01 g/mL的壳聚糖,成膜液浓度0.015 g/mL,成膜时间30 min制备出的荧光微球在模拟胃、肠液中表现出良好的膜强度及稳定性.为研究壳聚糖-海藻酸钙载药微球在体内的分布、吸收、降解特性提供了适宜的入体实验条件.     

5,10,15-三对氯苯基-20-邻(α-氧基硬脂酸)苯基卟啉Langmuir-Blodgett膜的性质研究

研究了具有双亲性的5,10,15-三对氯苯基-20-邻(α-氧基硬脂酸)苯基卟啉(TSPP)在气-液界面上的成膜性能,制备了不同层数的TSPP LB膜.利用UV-vis分光光度计,小角x射线衍射,原子力显微镜等方法,研究了膜的表面形貌及卟啉分子在膜中的排列取向及相互作用.实验结果表明:双亲性的5,10,15-三对氯苯基-20-邻(α-氧基硬脂酸)苯基卟啉(TSPP)在气液界面上具有良好的成膜性能,制备的单层和多层LB膜性能稳定并具有良好的纵向均匀性和结构周期性.在旋转涂得的薄膜上,TSPP分子以聚集体的形式分散分布,未聚集的TSPP分子形成的薄膜,表面分布着大量针孔状的缺陷;LB膜表面平整均匀,TSPP分子的环平面紧密地排列在一起以羧基为支撑点垂直“站立”在基片平面上,分子侧链与基片平面成52.3°角排列.     

L-甲硫氨酸-壳聚糖分子印迹复合膜的制备与性能研究

采用本体聚合法,以壳聚糖(CTS)为基材,L-甲硫氨酸为印迹分子,聚乙二醇(PEG)2000、戊二醛为交联剂,制备了L-甲硫氨酸-戊二醛-聚乙二醇-壳聚糖分子印迹复合膜.实验结果表明:合成的L-甲硫氨酸-戊二醛-PEG-壳聚糖分子印迹复合膜的溶胀性和膜清水通量较好,对氨基酸的渗透量为0.130 mmol·cm-2和L,D-甲硫氨酸的分离因子为1.76.FT-IR、SEM、XRD和TGA表征分析显示:分子印迹膜表面平整、微观结构规整紧密,具有较低的结晶度和高热稳定性.     

壳聚糖乙烯基衍生物的合成及其对鸟嘌呤的印迹识别

以壳聚糖(CS)为原料,通过其活性基团与甲基丙烯酸缩水甘油酯(GMA)反应,制得水溶性的乙烯基壳聚糖衍生物(CS-GMA).用FTIR和XRD对所合成的衍生物进行了分析和表征.在印迹分子鸟嘌呤的存在下,利用该乙烯基壳聚糖衍生物为功能单体和乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,合成了可通过非共价自组装法形成多个识别位点的生物碱基-鸟嘌呤的分子印迹聚合物(MIP).通过静态吸附实验,用紫外分光光度法研究了CS-GMA的分子识别作用.结果表明分子印迹聚合物(MIP)对鸟嘌呤具有较高的识别能力及选择性.     

聚苯乙烯为致孔剂的分子印迹膜对溶菌酶吸附性能的研究

探索聚苯乙烯微球的添加对于分子印迹膜对溶菌酶(Lysozyme, Lyz)吸附性能的影响.以溶菌酶为模板分子,丙烯酰胺、N,N'-亚甲基双丙烯酰胺为功能单体、聚苯乙烯(Polystyrene,PS)微球为致孔剂,制备聚苯乙烯为致孔剂的分子印迹聚合物膜(PS-MIP).PS-MIP的吸附平衡时间为30 min,短于未添加聚苯乙烯微球的分子印迹聚合物膜(MIP);PS-MIP与MIP对于Lyz的吸附能力均明显好于聚苯乙烯为致孔剂的非分子印迹聚合物膜(PS-NIP)与未添加聚苯乙烯微球的非分子印迹聚合物膜(NIP);PS-MIP对Lyz的选择性要好于MIP,而卵清蛋白和牛血清白蛋白在PS-MIP和MIP上的荧光信号没有差别.实验结果表明,在分子印迹膜聚合过程中添加聚苯乙烯微球,有利于缩短吸附时间,增大溶菌酶的吸附量并提升选择性.     

QCM法研究模拟体液中生物有机模板对类骨磷酸钙盐晶体的诱导作用

天然生物矿化是一个具有相当长周期的过程,其最显著的特征是其无机晶体的生长受控于有机分子所形成的基质.本文在采用人工合成复合性基质-壳聚糖,并在短时间内由基质模板于模拟体液(SCS)中诱导出无机晶体羟基磷灰石(HAp),首次利用石英晶体微天平(QCM)灵敏度高的性质来实时、在线监测羟基磷灰石的生长过程,并通过所得到的实验数据来比较复合氨基酸生物小分子对壳聚糖模板的诱导能力.     

DNA-夜蓝结合光谱研究

:在脱氧核糖核酸(DNA)分子中,磷酸苷脱质子和碱基的质子化使双螺旋链构成双静电膜,带电荷的染料分子被双静电膜吸附,吸收光谱发生位移。本实验用微表面吸附-光谱修正技术(MSASC)研究了DNA与夜蓝(NB)染料分子间的相互作用,结果表明NB在DNA上的吸附聚集满足Langmuir单分子层吸附规律。     

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