二种状态的器件

The UV and IR spectroscopic studies of the monomer films showed that the photoreaction ratio of monomer (about 50%) was higher than the corresponding photosensitive polymer (about 10%, PVCi). The polarized IR spectra proved that obvious anisotropic absorption was displayed in the irradiated photosensitive film. With polarizing microscopy method, we found that these kinds of photoalignment films exhibited good alignment ability, and the stability of the photoalignment film could reach about 100℃. 2 A photosensitive self-assembled monolayer was fabricated that contained photo-cycloadditable groups, such as, coumarin and cinnamate. The reaction process were detected by contact angle method because the IR absorption of monolayer was very weak. The photosensitive self-assembled monolayer promote uniform alignment of nematic liquid crystals by LPUV, and it thermal stability could reach about 130℃. 3 A cationic bolaform amphiphiles was synthesized that had two photosensitive double bonds, and can be polymerized by ultraviolet. A layer-by-layer self-assembled deposition film was prepared in aqueous solution by using this material and poly (sodium 4-styrenesulfonate). The UV-Vis. spectra proved that the multilayers film was uniform and layer-by-layer. When LPUV irradiated the film, the photopolymerizable double bond underwent [2+2] cycloaddition, and the production of the reaction distributed along the polarized direction of incident LPUV. Polarized UV-Vis. spectra indicated that the irradiated self-assembled multiplayer film was anisotropic, and the dichromic ration is about 0.09, it is higher than the spin-coating method of photosensitive polymer or monomer. We used this anisotropic film as alignment layer of nematic liquid crystals, and obtained a uniform and stability alignment result, the static contrast ratio is about 100, which is very close to application of liquid crystal device. This thesis is an instance that the photochemical material was used in the physics region of liquid crystals, the route that was from photosensitive monomer, self-assembled monolayer film to self-assembled multiplayer film was undergone, by this logical research method photoailgnment of liquid crystal was extended and consummated.

围绕上述思路开展了如下工作：1合成了三种可进行光二聚反应的光敏小分子单体，LPUV 辐照制作了光控取向膜；用紫外-可见光谱法和红外光谱法分析了薄膜中的光化学反应，发现小分子的光反应程度可达到50%以上，至少比光敏高分子高出5倍；薄膜的偏振红外光谱证实，经过LPUV 辐照后薄膜出现了明显的各向异性；将小分子光控取向膜制成液晶器件，在偏光显微镜下观察看到均匀一致的液晶取向；并且热稳定性达到100℃左右，接近实用化要求。2制备了含肉桂酸、香豆素基团的自组装单层膜；采用接触角的方法监测自组装反应的动力学过程；紫外-可见光谱证实了自组装单层膜在石英基板表面形成；自组装单层膜经LPUV 辐照后能诱导液晶均匀取向，而且热稳定性可达130℃，热稳定性进一步提高。3合成了含有光敏双键的双季铵盐，在水溶液状态下将它和聚乙烯基苯磺酸钠沉积生成layer-by-layer 自组装多层膜，紫外-可见光谱证实这是一个逐层均匀的沉积；在LPUV 照射下，自组装膜中的光敏双键按照偏振方向发生[2+2]环加成反应，形成取向膜，用二向色性值评价的分子取向度高于高分子及小分子光控取向膜的水平；实验证明用自组装多层膜制成的液晶器件亮暗态均匀，静态对比度约为100，达到实用化器件的水平。

Secondly, the energy levels of every layer in a designed device have to be matched each other.Quantum chemical calculations were carried out in order to investigate the photoelectric performance of our target molecules. According to the results of our quantum chemical calculations, the HOMOs are usually distributed along the thiophene-perfluorocyclopentene-thiophene skeleton of diarylethene molecule in both of the open-ring state and closed-ring state.

实验表明，在阻挡层式光控载流子开关器件的设计中，要实现完全意义上的ON-OFF全开关，必须满足两个条件：一是作为光控载流子开关层的二芳基乙烯材料，必须具备足够大的开环态和闭环态之间的HOMO能级差异，在一种状态下有利于载流子的传输，在另一种状态下则可以顺利地阻挡载流子的传输；二是器件的各材料层之间的能级一定要互相匹配。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了