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The material with high dielectric constant can significantly affect the distribution of the electric field, so this kind of material has great potential in liquid crystal display. In this paper, polyvinylidene fluoride (PVDF) as alignment layer in liquid crystal display was analysed. The optical property, mechanical property, thermal stability and electrical property of PVDF were measured. Experiments show that the absorbance of PVDF material is 0.2 (or less) in visible light, which is better than the conventional alignment material polyimide (PI). The alignment effect can be generated by mechanical friction and the liquid crystal molecules are ordered or aligned, and PVDF can maintain good thermal stability as temperature is lower than 400°C. Since the dielectric constant of PVDF is usually between 6.0 and 8.0, it has significant effect on the distribution of the electric field in the liquid crystal display, and its dielectric loss is also less than PI. The lower operating voltage and the faster response time are obtained from the experiment. It can be confirmed by the experiments that PVDF could be used in liquid crystal display (LCD) as the alignment layer to improve LCD’s characteristics. [ABSTRACT FROM AUTHOR]

Based on the four cruises during 2006-2007, the chemicohydrographic characteristics and the seasonal variations of nutrients at 35 degrees N transect in the cold water mass of the Southern Yellow Sea were analyzed. The results showed that: In Winter, hydrological conditions in the eastern part of the section was significantly influenced by the Yellow Sea Warm Current, and the vertical mixing in the deep water had not reached the bottom, which led to the different distribution of the elements in the eastern and western part of the section, the vertically uniform distribution was presented in the west and the upper water of the east, while the stratification structure was found in the bottom water of the east. In Spring, the Yellow Sea warm current residual water and the Qingdao cold water mass were the most obviously hydrological characteristics, and because of the increasing of the temperature in the upper water and the weakening of the vertical mixing, the stability of the water column increased gradually; compared with winter, the contour trend of DO, pH and nutrients in deep water transferred to the more horizontal direction, and with the arrival of spring blooming, the nutrient concentrations in the upper water decreased significantly, besides, the subsurface chlorophyll maximum (SCM) phenomena also began to emerge. In Summer, the section was influenced by the thermocline and the Yellow Sea cold water mass, which was accompanied with the maximum value phenomenon of DO and pH, in addition, the nutrient concentrations were low in upper water and high in bottom water, and compared with spring, the further reduction of the nutrient concentrations existed in upper water, but the nutrient concentrations were increasing dominantly in the water below the thermocline. In Autumn, with the decreasing of the temperature in the upper water and the enhancing of the vertical mixing, the stability of the water column decreased, but the vertical mixing in the deep water was still not smooth, and the nutrient concentrations in the bottom water of the east were higher than those in summer. This study further revealed the influencing mechanism of the mixing, stratification as well as other physical processes on the vertical distribution and its seasonal variations of the elements.