The corrosion behavior of Mg,AZ31 and AZ91 has been evaluated in 3.5%NaCl solution using weight loss,electrochemical polarization and impedance measurements.Corrosion rate derived from the weight losses demonstrated t...The corrosion behavior of Mg,AZ31 and AZ91 has been evaluated in 3.5%NaCl solution using weight loss,electrochemical polarization and impedance measurements.Corrosion rate derived from the weight losses demonstrated the occurrence of steeply fast corrosion reaction on AZ91 alloy after three hours of immersion,indicating the start of galvanic corrosion.An increase of corrosion rate with immersion time was also observed for AZ31 but with lesser extent than AZ91 alloy.Whereas Mg metals showed a decrease of corrosion rate with immersion time,suggesting the formation of a protective layer on their surfaces.In contrast,the corrosion current density(I_(corr))derived from the Tafel plots,exhibited their corrosion resistances in order of Mg>AZ91>AZ31.Electrochemical charge transfer resistance(R_(ct))and double layer capacitance measured by electrochemical impedance spectroscopy(EIS),are well in accordance with the measured I_(corr).EIS measurements with time and microstructural examination of the corroded and uncorroded samples are helpful in elucidation of results measured by electrochemical polarization.展开更多
VLF （very low frequency） mode instability with parallel AC electric field was studied for generalized loss-cone distribution with an index j, which is reducible to bi-Maxwellian, loss- cone and delta function for j ...VLF （very low frequency） mode instability with parallel AC electric field was studied for generalized loss-cone distribution with an index j, which is reducible to bi-Maxwellian, loss- cone and delta function for j = 0, 1 and co. The particle trajectories and dispersion relation are obtained through a kinetic approach and method of characteristic solutions. The calculations are compared with the observations of low frequency waves of Voyager 2. The growth rate of plasma parameters suited to magnetosphere of Uranus is obtained. It is inferred that the magnitude as well as frequency of AC （alternating current） field increases the growth rate and widen the band width significantly. In addition to temperature anisotropy, particles in plasma having generalized loss-cone distribution provide an additional source of energy.展开更多
Silica host matrix containing neodymium which is potentially important for the formation of nanocrystalline metal oxides was prepared by solgel method, using tetra-ethoxysilane and Nd（NO3）3 as precursor materials.Th...Silica host matrix containing neodymium which is potentially important for the formation of nanocrystalline metal oxides was prepared by solgel method, using tetra-ethoxysilane and Nd（NO3）3 as precursor materials.The prepared samples were changed from amorphous to nanocrystallites phase at sintered temperature 550 °C（4 h）, 750 °C（8 h） and 950 °C（12 h）.The thermally treated sample microstructures were investigated using X-ray diffraction（XRD）, Fourier transformation infrared spectroscopy（FTIR）, and scanning electron mi-croscopy（SEM）.While a further increase of the temperature at 750 °C and annealing time（8 h） resulted in the formation of cubic and hexagonal Nd2O3 nanocrystallites.At constant sintering temperature 950 °C for 12 h, the samples showed sharper and intense peaks.The sizes of Nd2O3 nanocrystallites were characterized by XRD with average size ～46 nm.展开更多
Recent studies have demonstrated that treatment with erythro?poietin (EPO) protects the CNS from a variety of insults. The purpose of this study was to examine the relationship between EPO and the phenomena of ischemi...Recent studies have demonstrated that treatment with erythro?poietin (EPO) protects the CNS from a variety of insults. The purpose of this study was to examine the relationship between EPO and the phenomena of ischemic pre-conditioning. Transient retinal (HIOP) and cerebral (MCAo) ischemia was induced in the rat. Treatment with EPO resulted in significant展开更多
Therapeutic agents used to treat glaucoma are designed to decrease the intra-ocular pressure (IOP) either by decreasing the aqueous humor production in the ciliary body and/or by enhancing the aqueous humor drainage f...Therapeutic agents used to treat glaucoma are designed to decrease the intra-ocular pressure (IOP) either by decreasing the aqueous humor production in the ciliary body and/or by enhancing the aqueous humor drainage from the eye. Oral carbonic an-hydrase inhibitors (CAIs) were the mainstay in the glaucoma therapy but of late, these agents have become less popular due展开更多
文摘The corrosion behavior of Mg,AZ31 and AZ91 has been evaluated in 3.5%NaCl solution using weight loss,electrochemical polarization and impedance measurements.Corrosion rate derived from the weight losses demonstrated the occurrence of steeply fast corrosion reaction on AZ91 alloy after three hours of immersion,indicating the start of galvanic corrosion.An increase of corrosion rate with immersion time was also observed for AZ31 but with lesser extent than AZ91 alloy.Whereas Mg metals showed a decrease of corrosion rate with immersion time,suggesting the formation of a protective layer on their surfaces.In contrast,the corrosion current density(I_(corr))derived from the Tafel plots,exhibited their corrosion resistances in order of Mg>AZ91>AZ31.Electrochemical charge transfer resistance(R_(ct))and double layer capacitance measured by electrochemical impedance spectroscopy(EIS),are well in accordance with the measured I_(corr).EIS measurements with time and microstructural examination of the corroded and uncorroded samples are helpful in elucidation of results measured by electrochemical polarization.
文摘VLF （very low frequency） mode instability with parallel AC electric field was studied for generalized loss-cone distribution with an index j, which is reducible to bi-Maxwellian, loss- cone and delta function for j = 0, 1 and co. The particle trajectories and dispersion relation are obtained through a kinetic approach and method of characteristic solutions. The calculations are compared with the observations of low frequency waves of Voyager 2. The growth rate of plasma parameters suited to magnetosphere of Uranus is obtained. It is inferred that the magnitude as well as frequency of AC （alternating current） field increases the growth rate and widen the band width significantly. In addition to temperature anisotropy, particles in plasma having generalized loss-cone distribution provide an additional source of energy.
文摘Silica host matrix containing neodymium which is potentially important for the formation of nanocrystalline metal oxides was prepared by solgel method, using tetra-ethoxysilane and Nd（NO3）3 as precursor materials.The prepared samples were changed from amorphous to nanocrystallites phase at sintered temperature 550 °C（4 h）, 750 °C（8 h） and 950 °C（12 h）.The thermally treated sample microstructures were investigated using X-ray diffraction（XRD）, Fourier transformation infrared spectroscopy（FTIR）, and scanning electron mi-croscopy（SEM）.While a further increase of the temperature at 750 °C and annealing time（8 h） resulted in the formation of cubic and hexagonal Nd2O3 nanocrystallites.At constant sintering temperature 950 °C for 12 h, the samples showed sharper and intense peaks.The sizes of Nd2O3 nanocrystallites were characterized by XRD with average size ～46 nm.
文摘Recent studies have demonstrated that treatment with erythro?poietin (EPO) protects the CNS from a variety of insults. The purpose of this study was to examine the relationship between EPO and the phenomena of ischemic pre-conditioning. Transient retinal (HIOP) and cerebral (MCAo) ischemia was induced in the rat. Treatment with EPO resulted in significant
文摘Therapeutic agents used to treat glaucoma are designed to decrease the intra-ocular pressure (IOP) either by decreasing the aqueous humor production in the ciliary body and/or by enhancing the aqueous humor drainage from the eye. Oral carbonic an-hydrase inhibitors (CAIs) were the mainstay in the glaucoma therapy but of late, these agents have become less popular due
