The most general photocatalyst, TiO2 and WO3, are acknowledged to be ineffective in range of visible light. Therefore, many efforts have been directed at improving their activity such as: band-gap narrowing with non-metal element doping and making composites with high specific surface area to effectively separate electrons and holes. In this paper, the method was introduced to prepare a photo-active catalyst to visible irradiation by making a mixture with TiO2 and WO3. In the TiO2-WO3 composite, WO3 absorbs visible light creating excited electrons and holes while some of the excited electrons move to TiO2 and the holes remain in WO3. This charge separation reduces electron-hole recombination resulting in an enhancement of photocatalytic activity. Added Ag plays the role of electron acceptor, retarding the recombination rate of excited electrons and holes. In making a mixture of TiO2-WO3 composite, the mixing route affects the photocatalytic activity. The planetary ball-mill method is more effective than magnetic stirring route, owing to a more effective dispersion of aggregated powders. The volume ratio of TiO2(4) and WO3(6) shows the most effective photocatalytic activity in the range of visible light in the view point of effective separation of electrons and holes.
벼의 엽색은 시비시기를 결정하는데 주요한 인자로써 가시부 영역에서 해석하고, 이들 엽색을 지배하는 광합성색소는 T.L.C.로 분리하여 검토하였다. 1. 벼의 엽색은 413, 432, 453nm(청색부)와 662nm(적색부)에서 흡광되였고, 그 중에서 최대흡광은 432, 662 nm 이었다. 2. 양흡광도비(청색부/적색부)는 벼 생태형간에는 근 차이는 없었으나. 비료간에는 비료양이 증가할수록 적었다. 3. 양흡광도비와 엽색도 및 엽록소함량과는 부의 유의상관이 인정되었다. 4. 광합성색소 조성비율은 출수기에서는 녹색계통색소, 출수후 30일에는 황색계통색소의 조성비율이 각각 컸다. 5. 벼 생태형별 광합성색소율 Chl. a의 조성비율은 출수기에는 다수계품종이 일반계품종보다 컸고, 출수후 30일에는 일반계품종이 다수계품종보다 컸으나, carotene는 그 반대이었다.