In this paper, a crosslinked carboxymethyl starch (CCMS) was prepared with corn starch as the raw material, epichlorohydrin as the crosslinking agent, and chloroacetic acid as the etherifying agent through a series of crosslinking, alkalization, and etherification reactions, respectively. Nano-TiO2 was loaded onto the surface of the CCMS by the sol-gel method to obtain a TiO2/CCMS composite. The TiO2/CCMS composite was characterized by XPS, XRD, SEM, and BET. XPS showed that the surface chemical composition of the TiO2/CCMS composite material contained titanium; XRD diffraction patterns indicated that the crystal form of the TiO2/CCMS composite was a combination of the CCMS and anatase TiO2. The surface morphology obtained by SEM showed that there were nano-TiO2 particles on the surface of the CCMS. The specific surface area of the TiO2/CCMS composite was larger than that of CCMS. The adsorption-photodegradation performance of the TiO2/CCMS composite was also studied under UV irradiation, and the results showed that significant adsorption-photodegradation synergies occurred.
Environmental Chemistry Letters - Nanosilver (nAg) is increasingly being used in a wide array of fields, and its toxicity has been extensively studied. Here we present a review of environmental nAg... 相似文献
2004年5月10日云南怒江州福贡县石月亮乡发生泥石流等地质灾害,造成人员、经济重大损失。分析了此次泥石流形成的条件,并着重探讨了天气学成因,结果表明:脆弱的地质环境、陡峻的迎风坡、便于集水、集物的地形地貌和丰富的松散物质是怒江贡山泥石流易发生的有利地质地貌条件;连续性累积降水及短时间暴雨的产生为泥石流提供了较好的水源条件;高原短波槽与孟加拉湾南支槽东移合并,中、低层槽前西偏南暖湿气流500 h Pa偏西北气流是形成怒江暴雨过程的大尺度天气环流背景;地面辐合线、干线、低层显著湿区、湿舌等是导致降水的中尺度系统;高能高湿的潜在不稳定及近地层的水汽辐合是暴雨发生的有利条件;多普勒雷达图10~20 d Bz分散的絮状回波、部分35 d Bz块絮状回波、卫星云图多絮状对流云、无强对流云团活动反映此次暴雨过程为非对流性暴雨。 相似文献
The physical properties of gas and water are important in usage of gas reservoirs with water and water-soluble gas reservoirs. According to the Petroleum and Natural Gas Industry Standards SY/T5542-2009 of the People's Republic of China, by applying the crude oil multistage degassing method from the “Test Method for Reservoir fluid Physical Properties” and the formation water high-pressure property testing method described in the “Theory and Application of Reservoir Fluid Phase”, this investigation employed a Ruska 2370–601A phase analyzer to obtain data regarding gas–water ratios, water volume factors, compressibility coefficients, and densities. The results showed curve trends with changes in the temperature and pressure. The gas–water ratio was compared to the gas content of subsurface samples from the X water-soluble gas reservoir, suggesting that these findings might help in the analysis of water-soluble gas reservoirs. 相似文献