With sodium dodecyl sulfonate(SDS) as the phase transferring catalyst, N,N-Dilauryl chitosans with a high degree of alkyl group substitution were prepared and characterized by means of FTIR, 1H NMR and elemental ana...With sodium dodecyl sulfonate(SDS) as the phase transferring catalyst, N,N-Dilauryl chitosans with a high degree of alkyl group substitution were prepared and characterized by means of FTIR, 1H NMR and elemental analyses. The results indicate that the average degree of alkyl group substitution on the chitosan increases with decreasing the molecular weight of the chitosan. The fully N,N-dilaurylated chitosan was found to be dissolvable in chloroform. The collapsed pressures of the samples derived from chitosan with 3000, 5000 and 10000 dalton are 47.6, 48.2 and 51.0 mN/m, respectively. The surface area occupied by the monomer unit(glucosamine) of all those samples is 0.6 nm2.展开更多
Thermal diffusion of Si atoms at the interface in Mo/Si multilayers was observed with an imaging type soft X ray emission microscope developed by us. It was possible to observe the diffusion with 0.2nm depth resolutio...Thermal diffusion of Si atoms at the interface in Mo/Si multilayers was observed with an imaging type soft X ray emission microscope developed by us. It was possible to observe the diffusion with 0.2nm depth resolution in the direction normal to the interface by comparing the emission intensity for exactly the same position. The diffusion coefficient of Si atoms in Mo at 600℃ was roughly estimated to be 6.0×10 17 cm 2/s.展开更多
During investigating what causes the low yield of the polymerization product of 1,4-bis(quinolyl)-1,3-butadiyne(DQ), we found that the DQ crystals formed on the surface of PDQ cauld be polymerized to give blue cryst...During investigating what causes the low yield of the polymerization product of 1,4-bis(quinolyl)-1,3-butadiyne(DQ), we found that the DQ crystals formed on the surface of PDQ cauld be polymerized to give blue crystals, in which DQ could be sublimated and crystallized on the surface of PDQ film. According to the experimental results, the reason why the DQ crystals can be polymerized is that the sublimation of DQ changes the molecular orientation of DQ in the crystal. The crystals formed in epitaxial growth on the surface of DQ or PDQ during sublimation of DQ are suitable for 1,4-addition polymerization.展开更多
基金Supported by the National Natural Science Foundation of China(No.2 0 2 74 0 13) ,Key Project of the Fujian ProvincialScience and Technology(No.2 0 0 2 I0 0 4 ) and the Fujian Provincial Science Foundation of China(No.E0 110 0 2 7and C0 310 0 0 9)
文摘With sodium dodecyl sulfonate(SDS) as the phase transferring catalyst, N,N-Dilauryl chitosans with a high degree of alkyl group substitution were prepared and characterized by means of FTIR, 1H NMR and elemental analyses. The results indicate that the average degree of alkyl group substitution on the chitosan increases with decreasing the molecular weight of the chitosan. The fully N,N-dilaurylated chitosan was found to be dissolvable in chloroform. The collapsed pressures of the samples derived from chitosan with 3000, 5000 and 10000 dalton are 47.6, 48.2 and 51.0 mN/m, respectively. The surface area occupied by the monomer unit(glucosamine) of all those samples is 0.6 nm2.
文摘Thermal diffusion of Si atoms at the interface in Mo/Si multilayers was observed with an imaging type soft X ray emission microscope developed by us. It was possible to observe the diffusion with 0.2nm depth resolution in the direction normal to the interface by comparing the emission intensity for exactly the same position. The diffusion coefficient of Si atoms in Mo at 600℃ was roughly estimated to be 6.0×10 17 cm 2/s.
基金Supported by Core Research for Evolutional Science and Technology(CREST),Japan Science and Technology Corpo-ration(JST)
文摘During investigating what causes the low yield of the polymerization product of 1,4-bis(quinolyl)-1,3-butadiyne(DQ), we found that the DQ crystals formed on the surface of PDQ cauld be polymerized to give blue crystals, in which DQ could be sublimated and crystallized on the surface of PDQ film. According to the experimental results, the reason why the DQ crystals can be polymerized is that the sublimation of DQ changes the molecular orientation of DQ in the crystal. The crystals formed in epitaxial growth on the surface of DQ or PDQ during sublimation of DQ are suitable for 1,4-addition polymerization.
