Defect-related visible luminescence of ZnO nanorods annealed in oxygen ambient

ZnO nanorods prepared by a solution-phase method are annealed at different temperatures in oxygen ambient.The luminescence properties of the samples are investigated.In the same excitation condition,the photoluminescence(PL) spectra of all samples show an ultraviolet(UV) emission and a broad strong visible emission band.The asymmetric visible emis-sion band of annealed samples has a red-shift as the annealing temperature increasing from 200 ℃ to 600 ℃ and it can be deconvoluted into two subband emissions centered at 535 nm(green emission) and 611 nm(orange-red emission) by Gaussian-fitting analysis.Analyses of PL excitation(PLE) spectra and PL spectra at different excitation wavelengths reveal that the green emission and the orange-red emission have a uniform initial state,which can be attributed to the electron transition from Zn interstitial(Zni) to oxygen vacancy(Vo) and oxygen interstitial(Oi),respectively.     

大直径旋转井壁取心仪研制与应用

为解决传统液压驱动式旋转井壁取心仪存在的驱动钻头扭矩低、岩心收获率低等问题,研制一种基于直流电机驱动钻头、最大扭矩可达8N·m的大直径旋转井壁取心仪。阐述了仪器的结构、性能指标、工作原理,对取心探头作了重点介绍。仪器研制成功后在各油田地质区块得到应用,取心收获率达90%以上。