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The effects of different NH4+-N to NO3--N ratio (NH4+ /NO3-) (0, 1/8, 1/4 and 1/2) on growth and quality of bunching onion (Allium fistulosum L. var. caespitosum Makino) under high temperature stress (34℃/26℃, day/night) were studied in growth chamber by hydroponics. The results showed that the growth and quality of bunching onion were affected by NH4+ /NO3-. Plant weight and height, leaf number per plant were the highest in the treatment which NH4+ /NO3- was 1/8, and those in treatment without NH4+-N were higher than in other 2 treatments. With the NH4+ /NO3- increasing, nitrate concentration in bunching onion decreased. The concentration of vitamin C was the highest in the treatment which NH4+ /NO3- was 1/8, while concentration of soluble sugar, soluble protein and allicin were the highest in the treatment which NH4+ /NO3-was 1/2. Thus the growth and quality of bunching onion were better in the NH4+ /NO3- range of 1/8 to 1/4.

To improve the corrosion property of magnesium alloys, Zr-based amorphous composite coatings have been fabricated on AZ91D magnesium alloy by laser cladding using mixed powders Zr55Al10Ni5Cu30/SiC. The microstructure of the coating was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The corrosion resistance of the coatings was tested in 3.5wt.% NaCl solution. The results show that the coatings mainly consist of amorphous and different crystalline phases. The coatings compared with AZ91D magnesium alloy exhibit good corrosion resistance because of the presence of the amorphous phase in the coatings.

To improve the corrosion property of magnesium alloys, Mg-based amorphous composite coatings have been fabricated on AZ91D magnesium alloy by laser cladding using mixed powders Mg65Cu25Y10/SiC. The microstructure of the coating was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The corrosion resistance of the coatings was tested in 3.5wt.% NaCl solution. The results show that the coatings mainly consist of amorphous and different crystalline phases. The coatings compared to AZ91D magnesium alloy exhibit good corrosion resistance because of the presence of the amorphous phase in the coatings.