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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。 相似文献
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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. 相似文献
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《Composite Interfaces》2013,20(4-5):451-473
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. 相似文献
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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。 相似文献
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《Composite Interfaces》2013,20(4-6):433-446
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. 相似文献
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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. 相似文献