共查询到2条相似文献,搜索用时 15 毫秒
1.
The feasibility of photocatalytic degradation of the formaldehyde gas by titanium dioxide (TiO2)/polyester non-woven fabrics was studied. Tbe effects of parameters such as tbe concentration of TiO2 solution, pH value, and drying temperature on the photocatalytic degradation of the formaldehyde gas were also studied. The results showed that the photodegradation efficiency of the formaldehyde gas increased rapidly with the increasing of the concentration of TiO2 solution up to 15g/L, but when the concentration was in excess of 15g/L, the photodegradation efficiency decreased gradually and fluctuated due to light obstruction and disperse state of TiO2. Adjusting the pH value in the solution, the efficiency of photocatalytic degradation of the formaldehyde gas could be improved. The mechanisms of the reaction and the role of the additives were also investigated. After 42hours, TiO2/ polyester non-woven fabric showed no significant loss of the photocatalytic activity. 相似文献
2.
CUI Zhijiu YANG Jianqiang ZHANG Wei ZHAO Liang & XIE Youyu . College of Environmental Sciences Peking University Beijing China . State Key Laboratory of Loess Quaternary Geology ChineseAcademy of Sciences Shaanxi China . Geographic Science Resource Research Institute Chinese Acad-emy of Sciences Beijing China 《科学通报(英文版)》2004,49(11):1177-1184
Deep sea deposits, ice cores and loess deposits have been used extensively and successfully, to study global climatic changes. Since permafrost is a consequence of cold climates, indicators of permafrost can also be used to reconstruct ancient climates in certain areas during certain periods. The recent discovery of large areas of ice wedge networks, and determination of their ages, have enabled us to locate the southern boundary of the permafrost that ex-isted in China about 20 thousand years… 相似文献