We clarify how magnetic reconnection can be derived from magnetohydrodynamics （MHD） equations in a way that is easily understandable to university students. The essential mechanism governing the time evolution of th...We clarify how magnetic reconnection can be derived from magnetohydrodynamics （MHD） equations in a way that is easily understandable to university students. The essential mechanism governing the time evolution of the magnetic field is diffusion dynamics. The magnetic field is represented by two components. It is clarified that the diffusion of a component causes agene ration of another component that is initially zero and, accordingly, that the magnetic force lines are reconnected. For this reconnection to occur correctly, the initial magnetic field must be directed oppositely in the two regions, e.g., y 〉 0 and y 〈 O; must be concave （convex） for y 〉 0 （y 〈 0）; and must be saturated foryfar from the x axis, which would indicate the existence of the current sheet. It will be clear that our comprehension based on diffusion runs parallel to the common qualitative explanation about the magnetic reconnection.展开更多
Indomethacin has been encapsulated with polyelectrolyte multilayers for controlled release. Gelatin and alginate were alternatively deposited on indomethacin microcrystals. The released amount of indomethacin from coa...Indomethacin has been encapsulated with polyelectrolyte multilayers for controlled release. Gelatin and alginate were alternatively deposited on indomethacin microcrystals. The released amount of indomethacin from coated microcrystals in pH6. 8 phosphate buffer solution （PBS） was measured with a UV spectrophometer. The polyelectrolyte multilayer capsule thickness was proved to control the release rate. The effects of osmotic pressure existed during the release process of indomethacin from microcapsules coated by （gelatin/alginate） 4.展开更多
文摘We clarify how magnetic reconnection can be derived from magnetohydrodynamics （MHD） equations in a way that is easily understandable to university students. The essential mechanism governing the time evolution of the magnetic field is diffusion dynamics. The magnetic field is represented by two components. It is clarified that the diffusion of a component causes agene ration of another component that is initially zero and, accordingly, that the magnetic force lines are reconnected. For this reconnection to occur correctly, the initial magnetic field must be directed oppositely in the two regions, e.g., y 〉 0 and y 〈 O; must be concave （convex） for y 〉 0 （y 〈 0）; and must be saturated foryfar from the x axis, which would indicate the existence of the current sheet. It will be clear that our comprehension based on diffusion runs parallel to the common qualitative explanation about the magnetic reconnection.
基金The National Key Fundamental Research FundGrant number:9732003C8615700+1 种基金The National Natural Science Fund of ChinaGrant number:20376068
文摘Indomethacin has been encapsulated with polyelectrolyte multilayers for controlled release. Gelatin and alginate were alternatively deposited on indomethacin microcrystals. The released amount of indomethacin from coated microcrystals in pH6. 8 phosphate buffer solution （PBS） was measured with a UV spectrophometer. The polyelectrolyte multilayer capsule thickness was proved to control the release rate. The effects of osmotic pressure existed during the release process of indomethacin from microcapsules coated by （gelatin/alginate） 4.
