Ultralong and Mesoporous ZnO and γ-Al_2O_3 Oriented Nanowires Obtained by Template-assisted Hydrothermal Approach

Highly mesoporous Zn O and g-Al2O3nanowires（NWs） are both synthesized by a hydrothermal method using commercially available porous anodic aluminium oxide（AAO） as template. AAO membrane acts as template for Zn O NWs and both as template and precursor for g-Al2O3 NWs. The formation of intermediate phases of porous Zn6Al2（OH）16CO3and boehmite（g-Al OOH） were observed, both occurring during the hydrothermal synthesis of porous Zn O and g-Al2O3 NWs, respectively, and disappearing after annealing at 600 C. This novel template-assisted hydrothermal process leads to the formation of porous Zn O and g-Al2O3NWs（specific surface area of 192 m2 g 1and 263 m2 g 1, respectively）, showing pore sizes around 4 nm in diameter. The influence of the reaction parameters on the nanostructure morphology was also investigated. A Zn O seed layer, deposited on the AAO channels prior to the hydrothermal synthesis, leads to more compact Zn O nanowires（99 m2 g-1） protecting the AAO host from the chemical attack of the precursor solution.     

给"腰"一个伸展的空间

腰部位于你身体的最中间,它支撑和协调着你身体的所有动作。腰部的疾患常会使你坐立不安,甚至连躺下都很困难。因此,平时的锻炼和呵护必不可少。     

An analytical solution for the consideration of the effect of adjacent fuel elements

A new analytical method is described to deal with the Leakage Environmental Effect – the influence of the adjacent fuel element on the cross-section preparation. The method is discussed and classified in comparison with other methods given in the literature. The new method is based on the analytical solution of the two group diffusion equation for two adjacent fuel elements. The specifics needed to create a highly efficient analytical solution are discussed. The very promising quality of the results for this highly efficient method is demonstrated on a homogeneous test case and on several heterogeneous combinations of two fuel elements described in the PWR MOX/UO2 CORE TRANSIENT BENCHMARK. One important advantage is the unproblematic extension of the solution to two-dimensional problems, since the analytical solution for each fuel element will be of the identical structure. Only the filled in data for the four fuel element quarters will vary. The coupling of the fuel elements does not affect the exponential solutions, only the constants attached to the single exponentials. Thus, the coupling will be solved in a system of linear equations.