Let A be a row-finite k-graph without sources. We investigate the relationship between the complex Kumjian-Pask algebra KPc（A） and graph algebra C＊（A）. We identify situations in which the Kumjian-Pask algebra is ...Let A be a row-finite k-graph without sources. We investigate the relationship between the complex Kumjian-Pask algebra KPc（A） and graph algebra C＊（A）. We identify situations in which the Kumjian-Pask algebra is equal to the graph algebra, and the conditions in which the Kumjian-Pask algebra is finite-dimensional.展开更多
Poly（p-arylene sulfide ketone/Schiffbase） copolymers （PASK/SB） were prepared by solution polycondensation of 4,4＇-diflurobenzophenone （DFBP） and N-phenyl（4,4＇-diflurodiphenyl） ketimine （DFBI） with sodium s...Poly（p-arylene sulfide ketone/Schiffbase） copolymers （PASK/SB） were prepared by solution polycondensation of 4,4＇-diflurobenzophenone （DFBP） and N-phenyl（4,4＇-diflurodiphenyl） ketimine （DFBI） with sodium sulfide in the presence of sodium hydroxide under normal pressure. Elemental analyses, FT-IR, NMR, DSC, TGA and XRD were used to characterize the resultant copolymers. It was found that the copolymers had good thermal properties with glass transition temperature （Tg） of 155.0-172.0℃, melting temperature （Tm） of 298-344℃, 5% weight loss temperatures （Td） of 471.0-501.5℃. These copolymers were almost amorphous with the content of DFBI beyond 30%. The polymer with 100% DFBI had excellent solubility, and it could dissolve in some solvents such as tetrahydrofuran （THF） and N-methyl-2- pyrrolidone （NMP）. The processability of polymers was improved. Meantime the viscosity of PASK made from hydrolysis of PASK/SB （H-PASK/SB） was greatly improved from 0.135 dL/g to 0.605 dL/g.展开更多
基金Supported by Universitas Pendidikan Indonesia(Indonesia University of Education) Research Grant-Hibah Dosen Peneliti(Grant No.558/UN.40.8/LT/2012)
文摘Let A be a row-finite k-graph without sources. We investigate the relationship between the complex Kumjian-Pask algebra KPc（A） and graph algebra C＊（A）. We identify situations in which the Kumjian-Pask algebra is equal to the graph algebra, and the conditions in which the Kumjian-Pask algebra is finite-dimensional.
基金financially supported by the National High Technology Foundation of China(No.2007AA03Z561).
文摘Poly（p-arylene sulfide ketone/Schiffbase） copolymers （PASK/SB） were prepared by solution polycondensation of 4,4＇-diflurobenzophenone （DFBP） and N-phenyl（4,4＇-diflurodiphenyl） ketimine （DFBI） with sodium sulfide in the presence of sodium hydroxide under normal pressure. Elemental analyses, FT-IR, NMR, DSC, TGA and XRD were used to characterize the resultant copolymers. It was found that the copolymers had good thermal properties with glass transition temperature （Tg） of 155.0-172.0℃, melting temperature （Tm） of 298-344℃, 5% weight loss temperatures （Td） of 471.0-501.5℃. These copolymers were almost amorphous with the content of DFBI beyond 30%. The polymer with 100% DFBI had excellent solubility, and it could dissolve in some solvents such as tetrahydrofuran （THF） and N-methyl-2- pyrrolidone （NMP）. The processability of polymers was improved. Meantime the viscosity of PASK made from hydrolysis of PASK/SB （H-PASK/SB） was greatly improved from 0.135 dL/g to 0.605 dL/g.
