Influence of NH_4 Cl on the initial atmospheric corrosion of zinc was investigated viaquartz crystal microbalance (QCM) in laboratory at 80%RH and 25℃. The resultsshow that NH_4 Cl can accelerate the initial corrosio...Influence of NH_4 Cl on the initial atmospheric corrosion of zinc was investigated viaquartz crystal microbalance (QCM) in laboratory at 80%RH and 25℃. The resultsshow that NH_4 Cl can accelerate the initial corrosion of zinc. Mass gain increase withthe exposure time, but mass gain in the later doesn't change obviously due to theformation of the insoluble simonkolleite on zinc surface in the presence of NH_4 Cl.Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) wasused to characterize the corrosion products. Zn_5Cl_2(OH)_8·H_2O,(NH_4)_2ZnCl_4 andZnO are the corrosion products on zinc. Brief discussion on the mechanisms of at-mospheric corrosion of zinc in the presence of NH_4 Cl was introduced.展开更多
Chinese tamarisk(saltcedar)is a deciduous shrub that occurs widely across the Yellow River Delta in China.The spatial structure of Chinese tamarisk is believed to have an influence on the landscape and habitats of rar...Chinese tamarisk(saltcedar)is a deciduous shrub that occurs widely across the Yellow River Delta in China.The spatial structure of Chinese tamarisk is believed to have an influence on the landscape and habitats of rare birds.In this study,first,Chinese tamarisk is detected using Canny edge detector and mathematical morphological operators based on SPOT 5 fusion-ready imagery.Then the numbers,areas,locations,and patch spacing of Chinese tamarisk patches are calculated.The experiments show that the detection accuracy of Chinese tamarisk patches is about 93.4%after the disconnection of connected patches.The distribution orientation of about 70%of the patches is approximately south-north.About 91%of the minimum distances among the patches are between 12.5 and 57.5 m.The rose graph indicates that the main azimuth between patches is north--northwest,and the second is northeast and southeast.The present study indicates that the integrating Canny edge detector with the algorithms for extracting circular and elliptical objects based on mathematical morphology is simple and effective for detecting Chinese tamarisk patches and is easy to identify the spatial structure of Chinese tamarisk patches,which reduces the time and labor for the visual interpretation of Chinese tamarisk patches.展开更多
文摘Influence of NH_4 Cl on the initial atmospheric corrosion of zinc was investigated viaquartz crystal microbalance (QCM) in laboratory at 80%RH and 25℃. The resultsshow that NH_4 Cl can accelerate the initial corrosion of zinc. Mass gain increase withthe exposure time, but mass gain in the later doesn't change obviously due to theformation of the insoluble simonkolleite on zinc surface in the presence of NH_4 Cl.Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) wasused to characterize the corrosion products. Zn_5Cl_2(OH)_8·H_2O,(NH_4)_2ZnCl_4 andZnO are the corrosion products on zinc. Brief discussion on the mechanisms of at-mospheric corrosion of zinc in the presence of NH_4 Cl was introduced.
基金supported by a grant from the National Natural Science Foundation of China(Project No.41023010)a grant from the Strategic Priority Research Program of Chinese Academy of Sciences(Project No.XDA05050601).
文摘Chinese tamarisk(saltcedar)is a deciduous shrub that occurs widely across the Yellow River Delta in China.The spatial structure of Chinese tamarisk is believed to have an influence on the landscape and habitats of rare birds.In this study,first,Chinese tamarisk is detected using Canny edge detector and mathematical morphological operators based on SPOT 5 fusion-ready imagery.Then the numbers,areas,locations,and patch spacing of Chinese tamarisk patches are calculated.The experiments show that the detection accuracy of Chinese tamarisk patches is about 93.4%after the disconnection of connected patches.The distribution orientation of about 70%of the patches is approximately south-north.About 91%of the minimum distances among the patches are between 12.5 and 57.5 m.The rose graph indicates that the main azimuth between patches is north--northwest,and the second is northeast and southeast.The present study indicates that the integrating Canny edge detector with the algorithms for extracting circular and elliptical objects based on mathematical morphology is simple and effective for detecting Chinese tamarisk patches and is easy to identify the spatial structure of Chinese tamarisk patches,which reduces the time and labor for the visual interpretation of Chinese tamarisk patches.
