GaN光学微盘的显微荧光图像探讨

研制了不同厚度的直径为５－１５μｍ的ＧａＮ光学微盘,并 学微盘的显微荧光图像进行了细致观测和数据值采集。结果表明,在同一个ＧａＮ外延样品上由于厚度的差别,微盘呈现两种不同类型的荧光图像,     

Strukturkandidaten für Alkalimetallnitride

Structure Candidates for the Alkali Metal Nitrides The energy landscapes of the alkali metal nitrides Li₃N, Na₃N, K₃N, Rb₃N, and Cs₃N have been investigated, using global optimisation techniques and the energy lid method. For each compound, a large number of kinetically stable modifications capable of existence have been found. The compound Na₃N has been analyzed in greater detail, and a number of promising (metastable) structures have been identified.     

Nickel Molybdenum Bimetallic Nitrides as Efficient Catalysts for the Hydrodeoxygenation of Methyl Palmitate

Highly efficient catalysts play an important role in the effective use of biomass oil to produce clean fuel. In this work, pure-phase Ni−Mo bimetallic nitrides (Ni₂Mo₃N and Ni₃Mo₃N) with different stoichiometric ratios are prepared by temperature-programmed nitridation of the metal oxide precursors in ammonia, which are investigated in the hydrodeoxygenation of methyl palmitate in the fixed-bed reactor at moderate conditions. The physical and chemical properties of catalysts were evaluated by H₂-TPR, XRD, SEM, TEM, XPS, and CO chemisorption. The Ni₂Mo₃N catalyst presents the best methyl palmitate hydrogenation activity (con.%=95.4 %) and the maximum hexadecane selectivity (95.0 %), which is obviously higher than those of Ni₃Mo₃N and Mo₂N catalysts. By introducing transition metal Ni into the Mo₂N lattice to form nickel-molybdenum bimetallic nitride, the lattice structure and electronic structure of the Mo active center have been changed, which greatly enhances the hydrodeoxygenation performances for the transformation of biomass oil to clean fuel.