Using polyvinyl alcohol(PVA) and sodium dodecyl suifae(SDS) as the surfactans respectively, nano-size amorphous molybdenum dioxide powders were prepared by y-radiation method at ambient pressure and room temperature, ...Using polyvinyl alcohol(PVA) and sodium dodecyl suifae(SDS) as the surfactans respectively, nano-size amorphous molybdenum dioxide powders were prepared by y-radiation method at ambient pressure and room temperature, and the products were characterized by use of laser Raman spectra(LRS), X-ray powder diffraction(XRD) and transmisson electron micrograph(TEM). The experimental results reveal that the relative pure satnples can be obtained using PVA as sdrictant, and the average particle size is about 10nm, but using SDS as swhctant, the samples with the average particle size 30nm are a mixture of MoO2 and MoO3. This suggestes PVA is prior to SDS in the preparaion of nano-sized amorphous molybdenum dioxide powders by γ-radiation method.展开更多
OH redical induced oxidation of methionine and N-phosphoryl methioninein aqueous solutions has been investigated using optical pulse radiolytical technique, theinfluence of N-phosphoryl group on the radiolytical proce...OH redical induced oxidation of methionine and N-phosphoryl methioninein aqueous solutions has been investigated using optical pulse radiolytical technique, theinfluence of N-phosphoryl group on the radiolytical processes of methionine has beenexplained by molecular structure and the rate constants of oxidation of N-phosphoryl methionine (NDM) by the OH radicals at different pH values have been determined. Thisresearch result suggests that the phosphonate ester has a coordinating effect on the radioprotection of methionine to the biological systems.展开更多
文摘Using polyvinyl alcohol(PVA) and sodium dodecyl suifae(SDS) as the surfactans respectively, nano-size amorphous molybdenum dioxide powders were prepared by y-radiation method at ambient pressure and room temperature, and the products were characterized by use of laser Raman spectra(LRS), X-ray powder diffraction(XRD) and transmisson electron micrograph(TEM). The experimental results reveal that the relative pure satnples can be obtained using PVA as sdrictant, and the average particle size is about 10nm, but using SDS as swhctant, the samples with the average particle size 30nm are a mixture of MoO2 and MoO3. This suggestes PVA is prior to SDS in the preparaion of nano-sized amorphous molybdenum dioxide powders by γ-radiation method.
文摘OH redical induced oxidation of methionine and N-phosphoryl methioninein aqueous solutions has been investigated using optical pulse radiolytical technique, theinfluence of N-phosphoryl group on the radiolytical processes of methionine has beenexplained by molecular structure and the rate constants of oxidation of N-phosphoryl methionine (NDM) by the OH radicals at different pH values have been determined. Thisresearch result suggests that the phosphonate ester has a coordinating effect on the radioprotection of methionine to the biological systems.