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采用溶胶-凝胶法制备了Yb掺杂TiO2纳米光催化剂,并通过XRD和BET等手段进行了表征.以对苯二甲酸作为探针分子,结合化学荧光技术研究了光催化剂表面羟基自由基的生成;并以苯酚为光催化降解反应模型化合物,考察了光催化剂的活性.测定了苯酚在TiO2和Yb掺杂TiO2光催化剂上的吸附常数.结果表明:Yb掺杂使TiO2的粒径减小,比表面积增大,同时导致羟基自由基的生成速率增大.Yb掺杂有利于反应底物在催化剂表面的吸附,Yb的最佳掺入量为Yb/Ti摩尔比=0.8%. 相似文献
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Data reconciliation technology can decrease the level of corruption of process data due to measurement noise, but the presence of outliers caused by process peaks or unmeasured disturbances will smear the reconciled results. Based on the analysis of limitation of conventional outlier detection algorithms, a modified outlier detection method in dynamic data reconciliation (DDR) is proposed in this paper. In the modified method, the outliers of each variable are distinguished individually and the weight is modified accordingly. Therefore, the modified method can use more information of normal data, and can efficiently decrease the effect of outliers. Simulation of a continuous stirred tank reactor (CSTR) process verifies the effectiveness of the proposed algorithm. 相似文献
949.
《Journal of the European Ceramic Society》2005,25(5):695-702
Results are presented for the reaction of aluminium metal with zirconia ceramics under (reducing) sintering conditions. During hot-pressing the principal phase formed is zirconium monoxide which is shown to have a rock-salt cubic structure and a unit-cell dimension of 0.46258 nm.When pressureless sintered or hot-pressed using a yttria partially-stabilised zirconia, composite structures of ZrO, alumina and cubic zirconia are produced which are the result of reduction reactions which proceed through the liquid metal phase. The results are interpreted through X-ray diffraction, microstructural and phase equilibria considerations which show that the sintering gas also plays a role in reaction through the oxygen partial pressure.The results allow calculation of an approximate value of the free energy of formation of zirconium monoxide (−294,500 J mol−1) which is consistent with the reported values for the monatomic carbide and nitride of zirconium and with other similar transition metal carbide, nitride and monoxide series. 相似文献
950.
Mechanisms of energy deposition at the interface of particles in explosive compaction of metal powders are analyzed. A one-dimensional model of a spherically symmetric pore is proposed to reflect the collapse. The effect of heat conduction is taken into account in axisymmetric flow equations, and the temperature distribution during the sphere collapse is solved by the finite-difference method under the assumption that the material is rigid-plastic or thermoviscoplastic. The results show that the effect of heat conduction becomes more remarkable if the scale of the holes is small. During the collapse, the inner surface is converted from the elastoplastic to the fluid state, and its temperature becomes much higher than that of the remaining part of the sphere, which favors retaining of the amorphous structure in explosive consolidation of amorphous powders.__________Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 3, pp. 133–138, May–June, 2005. 相似文献