A dimer of styrylpyrone derivative, leiocarpin E (1), was isolated from the bark of Goniothalamus leiocarpus. Its structures was elucidated by means of spectral and chemical methods. The cytotoxicity of leiocarpin E ...A dimer of styrylpyrone derivative, leiocarpin E (1), was isolated from the bark of Goniothalamus leiocarpus. Its structures was elucidated by means of spectral and chemical methods. The cytotoxicity of leiocarpin E against HL-60 cells was tested.展开更多
A novel way for electrification of mineral particles by electronbeam irradiation was proposed. The effect of irradiation dose oncharge/mass ratio was investigated experimentally. The charge/massratio of electrified mi...A novel way for electrification of mineral particles by electronbeam irradiation was proposed. The effect of irradiation dose oncharge/mass ratio was investigated experimentally. The charge/massratio of electrified mineral powders after irradiation was meas- uredby an instrument based on the principle of electrostatic induction.The experimental results showed that the charge/mass ratio is lar-gely dependent on radiation dose and electric physical properties ofminerals. The mechanism of electrification by electron beam irradi-ation is discussed. it is suggested that the essential ofelectrification by electron beam irradiation is a process ofretardation and charge deposition of incident electrons in materials.展开更多
文摘A dimer of styrylpyrone derivative, leiocarpin E (1), was isolated from the bark of Goniothalamus leiocarpus. Its structures was elucidated by means of spectral and chemical methods. The cytotoxicity of leiocarpin E against HL-60 cells was tested.
基金[This work was financial supported by the National Natural Science Foundation of China (No.59874002).]
文摘A novel way for electrification of mineral particles by electronbeam irradiation was proposed. The effect of irradiation dose oncharge/mass ratio was investigated experimentally. The charge/massratio of electrified mineral powders after irradiation was meas- uredby an instrument based on the principle of electrostatic induction.The experimental results showed that the charge/mass ratio is lar-gely dependent on radiation dose and electric physical properties ofminerals. The mechanism of electrification by electron beam irradi-ation is discussed. it is suggested that the essential ofelectrification by electron beam irradiation is a process ofretardation and charge deposition of incident electrons in materials.
