ELASTIC BEHAVIOR OF PROTEIN-LIKE SINGLE CHAIN

The conformational properties and elastic behaviors of protein-like single chains in the process of tensile elongation were investigated by means of Monte Carlo method. The sequences of protein-like single chains contain two types of residues: hydrophobic (H) and hydrophilic (P). The average conformations and thermodynamics statistical properties of protein-like single chains with various elongation ratio λ were calculated. It was found that the mean-square end-to-end distance r increases with elongation ratio,λ. The tensor eigenvalues ratio of : decreases with elongation ratio λ for short (HP)x protein-like polymers, however, the ratio of : increases with elongation ratioλ,especially for long (H)x sequence. Average energy per bond increases with elongation ratioλ, especially for(H)x protein-like single chains. Helmholtz free energy per bond also increases with elongation ratioλ. Elastic force (f), energy contribution to force (fU) and entropy contribution to force (fs) for different protein-like single chains were also calculated.These investigations may provide some insights into elastic behaviors of proteins.     

稀土胺羧酸配合物的研究 I. {[MnGd(DTPA)(H2O)5]2·H2O}n配合物的合成和晶体结构

本文首次合成了{MnLn(DTPA)(H2O)5]·H2O}n异核链式配合物(Ln=Gd, Er, Y)单晶,测定了{[MnGd(DTPA)(H2O)5]2·H2O]n的单晶结构。     

模拟萃合物二(二甲基甲酰胺)氯化醋酸铀铣UO2(OAc)Cl(DMF)2的结构测定

本文通过对一系列UO2(OAc)Cl.L2类型的化合物进行了化学合成和分子结构的研究,进一步证明协萃化合物是真子的氯化醋酸铀酰而不是氯化铀酰与醋酸铀酰的混合物, 并阐明醋酸根离子与氯离子交换的机理。二(二甲基甲酰胺)氯化醋酸铀酰分子结构的测定显示出在OAc^-和Cl的混合介质中所产生的协同萃取效应。     

竹红菌甲素光敏氧化反应机制

本文报道了在竹红菌甲素的光敏氧化反应中, 原初反应产生了^1O2、O2和H2O2,在一些还原性底物(5-羟基色氨酸、色氨酸、组氨酸、蛋氨酸和赖氨酸等)的存在下, 体系中形成的O2量大大增加。证明了体系中的^1O2是通过三重态的竹红菌甲素和基态氧进行能量传递形成的, O2是体系中的竹红菌甲素负离子自由基和基态氧进行单电子转移的结果, H2O2是体系中存在的竹红菌甲素二价负离子还原基态氧的产物。在一些底物存在下, 次级反应产生了.OH。我们也发现竹红菌甲素具有弱的抽氢能力而生成一些有机自由基, 这些有机自由基的形成促进了各种活泼态氧的相互转化, 因此我们认为竹红甲素的光敏氧化是各种活泼态氧和一些有机自由基综合反应的结果。     

Interfacial Properties of Phosphate Glass Fiber/Poly(caprolactone) System Measured Using the Single Fiber Fragmentation Test

Phosphate glass fiber of the composition 20Na₂O–24MgO–16CaO–40P₂O₅ was produced using an in-house fiber drawing rig. The interfacial properties of the phosphate glass fiber/poly(caprolactone) (PCL) system were measured using the single fiber fragmentation test (SFFT). The system was calibrated using E-glass fibers and polypropylene system. This gave an interfacial shear strength (IFSS) of 4.1 MPa, which agrees well with other published data. The IFSS for the unsized (as drawn) phosphate glass fiber/PCL system was found to be 1.75 MPa. Fibers treated with 3-aminopropyl-triethoxy silane (APS) showed an IFSS of 3.82 MPa. X-ray photoelectron spectroscopic (XPS) analysis of unsized and silane sized fibers established the presence of silane on the fiber surface. Degradation tests of the silane treated fiber/PCL samples were carried out in deionised water at 37°C and it was found that the IFSS values decreased over time. Four others silanes were also investigated but APS gave the highest IFSS values.     

交流电方法用于单晶n-CdTe光电极性能的研究

本文应用循环伏安法研究了n型碲化镉单晶电极的光致腐蚀行为; 并运用PAR M368电化学阻抗系统测得了此电极在不同电位下的交流复阻抗图, 估算了此电极表面态密度及其它参数。实验结果表明, n-CdTe/液体结具有Sehottky结的特征, 此电极的Fermi能级可能有"钉扎"现象。     

氮氧自由基研究:XXI,水溶液中哌啶氮氧自由基单电子还原反应机理的极谱研究

本文采用取样直流极谱, 常规脉冲极谱, 微分脉冲极谱和交流极谱考察了,2,2,6,6-四甲基-4-羟基哌啶 -1-氧和2,2,6,6-四甲基-4-氧哌啶 -1-氧由基及2,2,6,6-四甲基哌啶 -1-氧自由基在水溶液中的还原反应, 并研究了它们的还原经历电化学过程 。     

KTiOPO4单晶膜钾离子选择性电极的研究

本文采用KTiOPO4单晶薄片作为离子活性传感膜, 制备了钾离子选择性电极。20℃时, 其线性响应范围为1.2×10^-^5～1.0mol.dm^-^3氯化钾溶液, 平均响应斜率为58mV/-lgak, 对钠离子的电位选择性系数为4.0×10^-^4。该电极的优点是电极斜率受酸度变化影响小, 稳定性和重现性好, 寿命长。     

[Pb(NTO)~2(H~2O)]的制备, 分子结构和热分解机理的研究

通过3-硝基-1, 2, 4-三唑-5-酮(NTO)的钠盐水溶液与硝酸铅水溶液反应, 制备了标题配合物, 并用TG-DTG、元素分析、13^C NMR分析和红外光谱对它进行了表征。其结构用单晶分析法测定, 所得晶体学参数为: a=0.7284(2), b=1.2166(3), c=1.2310(3)nm, β=90.36(2)°, V=1.0908(4)nm^3, Z=4, D~c=2.96g.cm^-3,μ=156.40cm^-1, F(000)=888; 晶体属单斜晶系, 空间群为P2/n, 最终偏离因子R为0.0667。根据TG-DTG和FT-IR技术得到的分析结果, 提出了线性升温条件下标题配合物的热分解机理。