The spark plasma sintering (SPS) technique was introduced into the field ofNdFeB preparation due to its own advantages. High property NdFeB magnets with fine grains wereprepared by SPS method. The corrosion behaviors ...The spark plasma sintering (SPS) technique was introduced into the field ofNdFeB preparation due to its own advantages. High property NdFeB magnets with fine grains wereprepared by SPS method. The corrosion behaviors of SPS NdFeB were studied by electrochemicalmeasurements and 92 percent RH hyther tests at 353 K. The results were compared with those of thetraditional sintered NdFeB magnets. It shows that both the SPS NdFeB and the traditional sinteredNdFeB have good corrosion resistance in alkaline environment due to surface passivation; while, thefine grain microstructure of SPS NdFeB results in a more homogeneous phase composition distributionand thus reduces the electrochemical inhomogenity between the ferromagnetic phase and the Nd-richinter-granular phase in the magnet. Therefore, the SPS NdFeB exhibits better corrosion resistancethan the traditional sintered NdFeB in neutral and weak acidic environment.展开更多
Abstract: The seed embryos of Isatis indigotica Fort were exposed to He-Ne laser (5.23 mW/mm2, radiated for 5 min) and microwave (1.26 mW/mm2, radiated for 8 s) irradiation to determine the effects of microwave and He...Abstract: The seed embryos of Isatis indigotica Fort were exposed to He-Ne laser (5.23 mW/mm2, radiated for 5 min) and microwave (1.26 mW/mm2, radiated for 8 s) irradiation to determine the effects of microwave and He-Ne laser pretreatment on enzyme activities, and biophoton emission of cotyledon. Then: (i) changes in the activities of enzymes in I. indigotica cotyledon (such as amylase, transaminase, and proteinase) were measured to investigate the effects of He-Ne laser and microwave pretreatment; and (ii) biophoton emission was measured to determine the speed of cell division and metabolism. Results from these experiments indicated that: (i) the activities of amylase, transaminase, and proteinase of the cotyledon pretreated by He-Ne laser and microwave were significantly increased; and (ii) the intensity of biophoton emission was enhanced significantly by He-Ne laser and microwave irradiation. These changes suggest that He-Ne laser and microwave pretreatment can improve the inner energy of seeds, lead to an enhancement of cotyledon enzymes, and speed up the metabolism of the cell, resulting in significantly increased biophoton emission. Moreover, the mechanism of action of the effects of laser and microwave radiation on the microcalorimetric parameters, enzyme activities, and biophoton emission of seeds is discussed on the basis of the results obtained.展开更多
文摘The spark plasma sintering (SPS) technique was introduced into the field ofNdFeB preparation due to its own advantages. High property NdFeB magnets with fine grains wereprepared by SPS method. The corrosion behaviors of SPS NdFeB were studied by electrochemicalmeasurements and 92 percent RH hyther tests at 353 K. The results were compared with those of thetraditional sintered NdFeB magnets. It shows that both the SPS NdFeB and the traditional sinteredNdFeB have good corrosion resistance in alkaline environment due to surface passivation; while, thefine grain microstructure of SPS NdFeB results in a more homogeneous phase composition distributionand thus reduces the electrochemical inhomogenity between the ferromagnetic phase and the Nd-richinter-granular phase in the magnet. Therefore, the SPS NdFeB exhibits better corrosion resistancethan the traditional sintered NdFeB in neutral and weak acidic environment.
文摘Abstract: The seed embryos of Isatis indigotica Fort were exposed to He-Ne laser (5.23 mW/mm2, radiated for 5 min) and microwave (1.26 mW/mm2, radiated for 8 s) irradiation to determine the effects of microwave and He-Ne laser pretreatment on enzyme activities, and biophoton emission of cotyledon. Then: (i) changes in the activities of enzymes in I. indigotica cotyledon (such as amylase, transaminase, and proteinase) were measured to investigate the effects of He-Ne laser and microwave pretreatment; and (ii) biophoton emission was measured to determine the speed of cell division and metabolism. Results from these experiments indicated that: (i) the activities of amylase, transaminase, and proteinase of the cotyledon pretreated by He-Ne laser and microwave were significantly increased; and (ii) the intensity of biophoton emission was enhanced significantly by He-Ne laser and microwave irradiation. These changes suggest that He-Ne laser and microwave pretreatment can improve the inner energy of seeds, lead to an enhancement of cotyledon enzymes, and speed up the metabolism of the cell, resulting in significantly increased biophoton emission. Moreover, the mechanism of action of the effects of laser and microwave radiation on the microcalorimetric parameters, enzyme activities, and biophoton emission of seeds is discussed on the basis of the results obtained.
