青蒿素的Raman光谱研究

本文对固态青蒿素的FT-Raman光谱和普通Raman光谱以及低浓度(1×10^-^5mol/L)青蒿素水溶液的表面增强Raman散射(SERS)光谱进行了检测, 着重观察了1756cm^-^1六元内酯环振动谱带, 发现其在FT-Raman和普通Raman光谱中表现为强振动, 而在SERS光谱中此振动谱带消失, 说明分子内酯环发生了破裂。根据1756cm^-^1谱带的变化以及724cm^-^1过氧基团振动频率的位移, 对青蒿素在银表面上的吸附取向进行了研究。还研究了青蒿素与氯高铁血红素的作用情况, 发现两者作用后, 明显改变了青蒿素在银表面上的吸附。     

Interfacial modification for controlling silica–polysiloxane interactions and bonding in some elastomeric composites

Silica reinforcing fillers were generated using the sol-gel approach and their surfaces were modified using either a vinyl alkoxysilane (to provide permanent bonding to a host poly(dimethylsiloxane) elastomer), or a hemiacetal ester (to provide bonding that could be thermally ruptured). The surface areas of the fillers were measured by nitrogen absorption, and their morphologies, interfacial structures, and crosslinking to the elastomer were characterized by ultra small angle and small angle X-ray scattering, scanning electron microcopy, and Fourier-transform infrared spectroscopy. Increasing the amount of the silane coupling agent decreased silica domain sizes, with corresponding increases in surface area and stronger filler-polymer interactions. Vinyltrimethoxysilane had a larger effect than vinylmethyldimethoxysilane. The tensile moduli, tensile strengths, and degrees of toughness of the composites were determined using stress-strain measurements in elongation, both under near-equilibrium conditions and under continuous extension. The permanently bonded modifications gave composites with improved mechanical properties. Rupturing the hemiacetal ester bonding at 120-150°C gave some increase in ultimate stress, maximum elongation, and toughness, thus underscoring the importance of interactions or 'networking' between filler particles.     

一个新的用于反应散射计算的L^2平动基函数集合

本文通过构造新的L^2平动基函数集合改进了Shima-Baer方法.新集合中不再含有任何人工可调参数,取而代之的是反应体系的分子特性常数.由于在平动基函数中含有在非经典区域内的高度衰减因子,从而大大提高了反应几率对平动基函数展开的收敛速度.对共线交换反应H+H~2→H~2+H的计算结果表果,对平均基函数展开的收敛速度已接近包含畸变势的计算结果.改进后的Shima-Baer方法计算量明显降低.     

单取代苯的多重散射Xα研究

多重散射Xα方法讨论了氟苯、苯胺、硝基苯和苯腈的电离能、π轨道的电荷分布、π轨道的系数及等值图形. 表明多重散射Xα方法的波函数和电荷分布在描述取代苯活化位置方面存在某种局限性, 讨论了改善的可能途径.     

氟碳磷脂的合成及其脂质体的生成

合成了两种具有氟碳疏水性链的磷脂, 其极性部分分别为胆碱和磷酸根. 超声分散下, 上述两种磷脂均可形成腈质体, 以电子显微镜观察和动态光散射测定得到胆碱形成的脂质体的尺寸在32-37nm左右. 而对后者的光散射测定得出的尺寸较大并与溶液的pH值有关. 具有胆极性基的氟碳脂质体如同相应的碳氢磷脂一样, 具有包容水溶性受物的能力,但透光性更好. 从荧光探针的荧光强度对温度变化的研究指出, 在53℃左右胆碱型氟碳脂质体发生了相变.     

非水体系中甲醇在粗糙铂电极上解离吸附的表面增强拉曼 光谱研究

利用共焦显微拉曼系统和表面增强拉曼散射(SERS)效应研究了非水体系中甲醇在粗糙铂电极上的解离吸附过程。结果表明：甲醇在粗糙铂电极上解离吸附后产生了毒性中间物CO,在较负的电位区间内,H与CO共吸附于电极表面并影响CO的吸附行为,随电位正移,ν~P~t~-~C的变化可以用电化学Stark效应进行解释,而ν~C~~O的变化则是由于电化学Stark效应和CO偶极耦合的共同作用所引起的。     

Synthesis of Novel Double Network Hydrogels via Atom Transfer Radical Polymerization

Novel double network (DN) hydrogels were prepared via atom transfer radical polymerization (ATRP) of the first network using two different initiators, and followed by ultraviolet (UV) photo-initiated polymerization for the second network. The first networks of DN hydrogels were prepared by using two different initiators; one is a one-side initiator, and the other is a double-side initiator. The mechanical properties of various DN gels, such as water content and compressive strength, were studied. The network structure of the DN hydrogels was also characterized by dynamic light scattering. Thus, we demonstrated that the ATRP method is useful to control the network structure of the first network for DN gels. Extensive inhomogeneous structure of the first network was obtained by ATRP method and increased both the swelling degree and softness of DN gels.     

有限层Langmuir-Blodgett类晶型薄膜微观结构与超分子结构的小角X射线散射研究

本文应用SAXS与微机模型拟合(MCMI)研究了-LB(S为芪唑杰)薄膜与SA-LB(SA为芪唑盐/花生酸镉)薄膜的微观结构与超分子结构, 以及这类LB薄膜凝聚态不稳定的原因。结果指出: 第一, 从π-A曲线可知, S与A的脂肪链可以类似于脂肪酸晶胞形成二维类晶系结构; 第二, 随着分子比R~M=S/A=0到1, S和A之间发生了人分散相至连续相的相逆转; 第三, S在二维类晶系中处于不稳定的近似伸直型的高能态构象,然而, 哑铃形的芪唑基类似于芪趋向于作倾斜状密堆砌, S的两条脂肪链则倾向于转变为稳定的全反式燕尾开的低能态构象, 仅占S分子长约2/3的脂肪链亦降低了S分子间与S-A分子间的凝聚力, 这就导致了S连续相的二维类晶系存在大量晶格缺陷, 故只能形成4~6层不稳定的Y型LB薄膜; 第四, 存放一月后, 这种不稳定的S连续相的层状超分子结构极易存坏和崩塌。     

乙基氰乙基纤维素溶致性液晶的研究

纤维素和纤维素衍生物在适当的溶剂中可以形成溶致性液晶, 乙基氰乙基纤维素是纤维素的一种混合醚类衍生物, 本文研究了其溶致性液晶的形成, 结构以及不同溶剂对形成液晶所产生的影响.     

Two-Soliton Solutions of Axially Symmetric Metrics

Stationary axially symmetric solutions of Einstein's field equations generated by the soliton technique are presented in this paper with Laplace's solution as seed. The solutions are asymptotically flat and the Schwarzschild, Kerr and Kerr-NUT metrics are contained in it. The constructed solutions possess an event horizon. The surface area of the event horizon is evaluated. Finally, the solutions presented in this paper are compared with the solutions of Manko. A simple transformation technique is discussed by which one can directly obtain the solutions of Gutsunaev and Manko simply by adjusting a parameter related to the Inverse Scattering Method.