Abstract： It was discussed that the way to reflect the internal relations between judgment and identification, the two most fundamental ways of thinking or cognition operations, during the course of the semantic netw...Abstract： It was discussed that the way to reflect the internal relations between judgment and identification, the two most fundamental ways of thinking or cognition operations, during the course of the semantic network knowledge representation processing. A new extended Petri net is defined based on qualitative mapping, which strengths the expressive ability of the feature of thinking and the mode of action of brain. A model of semantic network knowledge representation based on new Petri net is given. Semantic network knowledge has a more efficient representation and reasoning mechanism. This model not only can reflect the characteristics of associative memory in semantic network knowledge representation, but also can use Petri net to express the criterion changes and its change law of recognition judgment, especially the cognitive operation of thinking based on extraction and integration of sensory characteristics to well express the thinking transition course from quantitative change to qualitative change of human cognition.展开更多
The production of Ph3Sn–O–SBA-15(Ph3Sn SBA)was achieved by heating triphenyltin chloride and SBA-15in N-methylpyrrolidone at 190°C for 5 h using triethylamine as a catalyst.The composition,structure,and surface...The production of Ph3Sn–O–SBA-15(Ph3Sn SBA)was achieved by heating triphenyltin chloride and SBA-15in N-methylpyrrolidone at 190°C for 5 h using triethylamine as a catalyst.The composition,structure,and surface physical and chemical properties of Ph3Sn SBA were characterized using inductively coupled plasma-atomic emission spectroscopy(ICP-AES),13C,119Sn and29Si solid-state nuclear magnetic resonance(NMR)spectroscopy in situ pyridine infrared spectroscopy(Py-IR),N2adsorption–desorption isotherms,X-ray diffraction(XRD)and transmission electron microscopy(TEM).The results of ICP-AES and organic elemental analysis showed that the grafting yield of Sn was 17%(by mass)for Ph3Sn SBA.The elemental analysis and solid-state NMR results for Ph3Sn SBA were consistent with grafting of triphenyltin on SBA-15.The N2adsorption–desorption,XRD and TEM analyses showed that Ph3Sn SBA retained an ordered hexagonal mesoporous structure,resulting in decreases in the surface area,pore size and mesopore volume,and an increase in acidity as compared with SBA-15.The Hammett acidity function(H0)value and the number of acid sites for Ph3Sn SBA,obtained by the Hammett methods,were 2.77–3.30 and 2.07 mmol·g-1,respectively.The Friedel–Crafts acylation of toluene and acetic anhydride over Ph3Sn SBA was investigated.The yield of methylacetophenone(MAP)and the selectivity for 4-methylacetophenone(PMAP)were 79.56%and 97.12%,respectively,when the conditions were n(toluene):n(anhydride)=2.0:1.0 with 6%(by mass)catalyst,and heating under reflux for 5 h.The PMAP selectivity still reached 93.11%when Ph3Sn SBA was used for the fifth time under the same reaction conditions.展开更多
文摘Abstract： It was discussed that the way to reflect the internal relations between judgment and identification, the two most fundamental ways of thinking or cognition operations, during the course of the semantic network knowledge representation processing. A new extended Petri net is defined based on qualitative mapping, which strengths the expressive ability of the feature of thinking and the mode of action of brain. A model of semantic network knowledge representation based on new Petri net is given. Semantic network knowledge has a more efficient representation and reasoning mechanism. This model not only can reflect the characteristics of associative memory in semantic network knowledge representation, but also can use Petri net to express the criterion changes and its change law of recognition judgment, especially the cognitive operation of thinking based on extraction and integration of sensory characteristics to well express the thinking transition course from quantitative change to qualitative change of human cognition.
基金Supported by the National Science Foundation of Heilongjiang Province(B201010)the Education Department of Heilongjiang Province(12511595)
文摘The production of Ph3Sn–O–SBA-15(Ph3Sn SBA)was achieved by heating triphenyltin chloride and SBA-15in N-methylpyrrolidone at 190°C for 5 h using triethylamine as a catalyst.The composition,structure,and surface physical and chemical properties of Ph3Sn SBA were characterized using inductively coupled plasma-atomic emission spectroscopy(ICP-AES),13C,119Sn and29Si solid-state nuclear magnetic resonance(NMR)spectroscopy in situ pyridine infrared spectroscopy(Py-IR),N2adsorption–desorption isotherms,X-ray diffraction(XRD)and transmission electron microscopy(TEM).The results of ICP-AES and organic elemental analysis showed that the grafting yield of Sn was 17%(by mass)for Ph3Sn SBA.The elemental analysis and solid-state NMR results for Ph3Sn SBA were consistent with grafting of triphenyltin on SBA-15.The N2adsorption–desorption,XRD and TEM analyses showed that Ph3Sn SBA retained an ordered hexagonal mesoporous structure,resulting in decreases in the surface area,pore size and mesopore volume,and an increase in acidity as compared with SBA-15.The Hammett acidity function(H0)value and the number of acid sites for Ph3Sn SBA,obtained by the Hammett methods,were 2.77–3.30 and 2.07 mmol·g-1,respectively.The Friedel–Crafts acylation of toluene and acetic anhydride over Ph3Sn SBA was investigated.The yield of methylacetophenone(MAP)and the selectivity for 4-methylacetophenone(PMAP)were 79.56%and 97.12%,respectively,when the conditions were n(toluene):n(anhydride)=2.0:1.0 with 6%(by mass)catalyst,and heating under reflux for 5 h.The PMAP selectivity still reached 93.11%when Ph3Sn SBA was used for the fifth time under the same reaction conditions.
