Both whisker and nanometer MgSO4·5Mg(OH)2·3H2O(MOS) were prepared by hydrothermal method at 140℃for different times, using NaOH and MgSO4·7H2O as raw materials. The MgSO4·5Mg(OH)2·3H2O part i...Both whisker and nanometer MgSO4·5Mg(OH)2·3H2O(MOS) were prepared by hydrothermal method at 140℃for different times, using NaOH and MgSO4·7H2O as raw materials. The MgSO4·5Mg(OH)2·3H2O part icles were characterized by powder X ray diffraction(XRD),thermal analysis(TGA DSC), infrared spectroscopy(FT IR),transmission electron microscopy(SEM) and scanning electron microscopy(TEM). The size distribution in whisker like and nanocrystalline materials arein the range of 10～50μm and 10～20nm respectively. The whisker MOS is metastable phase in MgSO4 NaOH H2O system at 140℃,whereas nanometer MOS is stable phase.展开更多
Owing to having very strong bioactivity, oligo-peptides can be used as the medication or the pre-medication and become the studying focus now. Existing methods for synthesizing oligo-peptides included liquid phase pep...Owing to having very strong bioactivity, oligo-peptides can be used as the medication or the pre-medication and become the studying focus now. Existing methods for synthesizing oligo-peptides included liquid phase peptide synthesis, solid phase peptide synthesis and enzymatic peptide synthesis. In this paper, a new method for synthesizing oligo-peptides by phosphorus oxychloride activation was reported. With the assistance of phosphorus oxychloride, the phosphorylation of L-valine could take place and then was assembled into oligo-peptides, which were analyzed by electrospray ionization mass spectrometry(ESI-MS). On quenching with methanol, the reaction mixtures, which were produced under different reaction conditions, yielded the corresponding peptide methyl esters. Moreover, we found that, as the reaction conditions such as reaction time, solvent and temperature were changed, the length of peptides changed. And the length of peptides could be controlled by changing the reaction conditions.展开更多
文摘Both whisker and nanometer MgSO4·5Mg(OH)2·3H2O(MOS) were prepared by hydrothermal method at 140℃for different times, using NaOH and MgSO4·7H2O as raw materials. The MgSO4·5Mg(OH)2·3H2O part icles were characterized by powder X ray diffraction(XRD),thermal analysis(TGA DSC), infrared spectroscopy(FT IR),transmission electron microscopy(SEM) and scanning electron microscopy(TEM). The size distribution in whisker like and nanocrystalline materials arein the range of 10～50μm and 10～20nm respectively. The whisker MOS is metastable phase in MgSO4 NaOH H2O system at 140℃,whereas nanometer MOS is stable phase.
文摘Owing to having very strong bioactivity, oligo-peptides can be used as the medication or the pre-medication and become the studying focus now. Existing methods for synthesizing oligo-peptides included liquid phase peptide synthesis, solid phase peptide synthesis and enzymatic peptide synthesis. In this paper, a new method for synthesizing oligo-peptides by phosphorus oxychloride activation was reported. With the assistance of phosphorus oxychloride, the phosphorylation of L-valine could take place and then was assembled into oligo-peptides, which were analyzed by electrospray ionization mass spectrometry(ESI-MS). On quenching with methanol, the reaction mixtures, which were produced under different reaction conditions, yielded the corresponding peptide methyl esters. Moreover, we found that, as the reaction conditions such as reaction time, solvent and temperature were changed, the length of peptides changed. And the length of peptides could be controlled by changing the reaction conditions.
