A new synthetic strategy for the synthesis of novel 3-（3-（3-methyl-4-nitroisoxazol-5-yl）-2-phenyl-1-（5,7-diaryl-7H-thia- zolo[3,2-a]pyrimidin-3-yl）propyl）-5,7-diaryl-7H-thiazolo[3,2-a]pyrimidines （7a-i） analog...A new synthetic strategy for the synthesis of novel 3-（3-（3-methyl-4-nitroisoxazol-5-yl）-2-phenyl-1-（5,7-diaryl-7H-thia- zolo[3,2-a]pyrimidin-3-yl）propyl）-5,7-diaryl-7H-thiazolo[3,2-a]pyrimidines （7a-i） analogues is described. Reaction of 3-（2- （3-methyl-4-nitroisoxazole-5-yl）-l-phenylethyl）pentane-2,4-dione （3） with two moles of thiourea in presence of iodine and CuO afforded 4-（1-（2-aminothiazol-4-yl）-3-（3-methyl-4-nitroisoxazol-5-yl）-2-aryl propylthiazol-2-amine （5）. Compound 5 on reaction with two moles of chalcone （6） furnished novel 3-（3-（3-methyl-4-nitroisoxazol-5-yl）-2-phenyl-1-（5,7-diaryl-7H-thiazolo[3,2- a]pyrimidin-3-yl）propyl）-5,7-diaryl-7H-thiazolo[3,2-a ]pyrimidines （Ta-i）.展开更多
This paper presents an experimental investigation on fracture behavior of epoxy resin-carbon fibers composites interleaved with both neat polyacrylonitrile （PAN） nanofibers and A1203-PAN nanofibers. In particular, t...This paper presents an experimental investigation on fracture behavior of epoxy resin-carbon fibers composites interleaved with both neat polyacrylonitrile （PAN） nanofibers and A1203-PAN nanofibers. In particular, the paper focuses on the effect of adding Al2O3 nanopartiles in PAN nanofibers, which were incorporated in unidirectional （UD） laminates. The effectiveness of adding a thin film made of Al2O3-PAN on the fracture behavior of the carbon fiber reinforced polymer （CFRP） has been addressed by comparing the energy release rates, obtained by testing double cantilever beam （DCB） samples under mode I loading condition. A general improvement in interlaminar fracture energy of the CFRP is observed when the both neat PAN nanofibers and Al2O3-PAN nanofibers are interleaved. However, higher interlaminar strength has been observed for the samples with a thin film of Al2O3-PAN nanofibers, suggesting a better stress distribution and stress transformation from resin-rich area to reinforcement phase of hybrid composites.展开更多
A series of novel imidazo[1,2-b]isoxazoles 3 and their Mannich bases 4–6 were synthesized via convenient reactions. The reaction of 3-aminoisoxazole 1 with substituted phenacyl bromides 2 in dry ethanol afforded the ...A series of novel imidazo[1,2-b]isoxazoles 3 and their Mannich bases 4–6 were synthesized via convenient reactions. The reaction of 3-aminoisoxazole 1 with substituted phenacyl bromides 2 in dry ethanol afforded the corresponding 6-methyl-3-aryl imidazo[1,2-b]isoxazoles 3 in good yields.Compounds 3 on treatment with 37% formaline and secondary amines furnished the corresponding novel Mannich bases viz., 6-methyl-3-aryl-2-（morpholine/pyrrolidin-1-yl/piperidin-1-yl）-methyl-imidazo[1,2-b]isoxazoles 4–6.展开更多
文摘A new synthetic strategy for the synthesis of novel 3-（3-（3-methyl-4-nitroisoxazol-5-yl）-2-phenyl-1-（5,7-diaryl-7H-thia- zolo[3,2-a]pyrimidin-3-yl）propyl）-5,7-diaryl-7H-thiazolo[3,2-a]pyrimidines （7a-i） analogues is described. Reaction of 3-（2- （3-methyl-4-nitroisoxazole-5-yl）-l-phenylethyl）pentane-2,4-dione （3） with two moles of thiourea in presence of iodine and CuO afforded 4-（1-（2-aminothiazol-4-yl）-3-（3-methyl-4-nitroisoxazol-5-yl）-2-aryl propylthiazol-2-amine （5）. Compound 5 on reaction with two moles of chalcone （6） furnished novel 3-（3-（3-methyl-4-nitroisoxazol-5-yl）-2-phenyl-1-（5,7-diaryl-7H-thiazolo[3,2- a]pyrimidin-3-yl）propyl）-5,7-diaryl-7H-thiazolo[3,2-a ]pyrimidines （Ta-i）.
文摘This paper presents an experimental investigation on fracture behavior of epoxy resin-carbon fibers composites interleaved with both neat polyacrylonitrile （PAN） nanofibers and A1203-PAN nanofibers. In particular, the paper focuses on the effect of adding Al2O3 nanopartiles in PAN nanofibers, which were incorporated in unidirectional （UD） laminates. The effectiveness of adding a thin film made of Al2O3-PAN on the fracture behavior of the carbon fiber reinforced polymer （CFRP） has been addressed by comparing the energy release rates, obtained by testing double cantilever beam （DCB） samples under mode I loading condition. A general improvement in interlaminar fracture energy of the CFRP is observed when the both neat PAN nanofibers and Al2O3-PAN nanofibers are interleaved. However, higher interlaminar strength has been observed for the samples with a thin film of Al2O3-PAN nanofibers, suggesting a better stress distribution and stress transformation from resin-rich area to reinforcement phase of hybrid composites.
文摘A series of novel imidazo[1,2-b]isoxazoles 3 and their Mannich bases 4–6 were synthesized via convenient reactions. The reaction of 3-aminoisoxazole 1 with substituted phenacyl bromides 2 in dry ethanol afforded the corresponding 6-methyl-3-aryl imidazo[1,2-b]isoxazoles 3 in good yields.Compounds 3 on treatment with 37% formaline and secondary amines furnished the corresponding novel Mannich bases viz., 6-methyl-3-aryl-2-（morpholine/pyrrolidin-1-yl/piperidin-1-yl）-methyl-imidazo[1,2-b]isoxazoles 4–6.
