The geometry,stability,binding energy and electronic properties of（SiO2）n and Ge（SiO2）n clusters（n = 7） have been investigated by Density functional theory（DFT）.The results show that the lowest energy structur...The geometry,stability,binding energy and electronic properties of（SiO2）n and Ge（SiO2）n clusters（n = 7） have been investigated by Density functional theory（DFT）.The results show that the lowest energy structures of Ge（SiO2）n are obtained by adding one Ge on the end site of the O atom or the Si near end site of the O atom in（SiO2）n.The chemical activation of Ge-（SiO2）n is improved compared with（SiO2）n.The calculated second-order difference of energies and fragmentation energies show that the Ge（SiO2）n clusters with n = 2 or 5 are stable.展开更多
The Cu/SiO2 catalyst prepared by incipient wetness method exhibited very high activity and selectivity for the vapor-phase synthesis of N-butylaniline from aniline and 1-butanol. When Cu loading was 0.70 mmol/g-SiO2 a...The Cu/SiO2 catalyst prepared by incipient wetness method exhibited very high activity and selectivity for the vapor-phase synthesis of N-butylaniline from aniline and 1-butanol. When Cu loading was 0.70 mmol/g-SiO2 and the catalyst precursor was calcined at 500 ℃, 1-butanol conversion reached 99%, and the selectivity of N-butylaniline exceeded 97%.展开更多
文摘以N,N-二甲基丙烯酰胺(DMAA)及甲基丙烯酸甲酯(MMA)为单体,Irgacure 2959为光引发剂,N,N′-二甲基双丙烯酰胺(Bis)为交联剂,利用紫外光引发自由基聚合制备了聚N,N′-二甲基丙烯酰胺(PDMAA)及P(DMAA-co-MMA)水凝胶,并通过加入少量表面改性后的纳米SiO2对该水凝胶进行改性,制得了P(DMAA-co-MMA)/纳米SiO2复合水凝胶,用FT-IR和SEM对产物进行了表征,同时研究该复合凝胶的溶胀动力学、消溶胀动力学、pH值响应性、离子强度等.该方法简便、快捷,大大缩短了聚合时间,合成过程仅需2—3 min.
基金Project supported by the foundation start up for high level talents of Shihezi university (No. RCZX200747)
文摘The geometry,stability,binding energy and electronic properties of（SiO2）n and Ge（SiO2）n clusters（n = 7） have been investigated by Density functional theory（DFT）.The results show that the lowest energy structures of Ge（SiO2）n are obtained by adding one Ge on the end site of the O atom or the Si near end site of the O atom in（SiO2）n.The chemical activation of Ge-（SiO2）n is improved compared with（SiO2）n.The calculated second-order difference of energies and fragmentation energies show that the Ge（SiO2）n clusters with n = 2 or 5 are stable.
文摘The Cu/SiO2 catalyst prepared by incipient wetness method exhibited very high activity and selectivity for the vapor-phase synthesis of N-butylaniline from aniline and 1-butanol. When Cu loading was 0.70 mmol/g-SiO2 and the catalyst precursor was calcined at 500 ℃, 1-butanol conversion reached 99%, and the selectivity of N-butylaniline exceeded 97%.
