The enthalpies of formation of some compounds are not easy to be measured experimentally. This paper reports the calculated values of the heat of formation for some novel moleclar sieves by a rnethod of consistant mol...The enthalpies of formation of some compounds are not easy to be measured experimentally. This paper reports the calculated values of the heat of formation for some novel moleclar sieves by a rnethod of consistant molecular mechanics force field.The enthalpies of formation of novel type molecular sieves: ZSM-48, ZSM-22, ZSM-23 and ZSM-18, have been calculated.展开更多
The C2 selectivity of catalyst La2O3 in okidative coupling of methane may beincreased by doping small amount of CaO. Some experimental techniques were adoptedsuch as measurement of fluorescence emission of Eu3+ doped ...The C2 selectivity of catalyst La2O3 in okidative coupling of methane may beincreased by doping small amount of CaO. Some experimental techniques were adoptedsuch as measurement of fluorescence emission of Eu3+ doped into La2O3, deterIninationsof the lattice paramters and XPS of the catalysts. The doping of CaO results in anincreace m ambient symmetry of La3+ and in the concentration for creating oxygen ionvacancies in La2O3.展开更多
A novel low temperature phase K3Sb0.3Y4O8. 6H2O was synthesized hydrother-mally from K2O-Sb2O3-Y2O3-H2O system, and characterized by means of XRD, SEM, IR,TG, DTA and ICP methods- The unit cell for the product is hexa...A novel low temperature phase K3Sb0.3Y4O8. 6H2O was synthesized hydrother-mally from K2O-Sb2O3-Y2O3-H2O system, and characterized by means of XRD, SEM, IR,TG, DTA and ICP methods- The unit cell for the product is hexagonal with the cell parame-ters a = 1.657 6nm and c= 1.186 5 nm. The volume of the cell is calculated to be 2. 823 3nm3. The product was decomposed into oxides from 310℃ to 390 ℃.展开更多
文摘The enthalpies of formation of some compounds are not easy to be measured experimentally. This paper reports the calculated values of the heat of formation for some novel moleclar sieves by a rnethod of consistant molecular mechanics force field.The enthalpies of formation of novel type molecular sieves: ZSM-48, ZSM-22, ZSM-23 and ZSM-18, have been calculated.
文摘The C2 selectivity of catalyst La2O3 in okidative coupling of methane may beincreased by doping small amount of CaO. Some experimental techniques were adoptedsuch as measurement of fluorescence emission of Eu3+ doped into La2O3, deterIninationsof the lattice paramters and XPS of the catalysts. The doping of CaO results in anincreace m ambient symmetry of La3+ and in the concentration for creating oxygen ionvacancies in La2O3.
文摘A novel low temperature phase K3Sb0.3Y4O8. 6H2O was synthesized hydrother-mally from K2O-Sb2O3-Y2O3-H2O system, and characterized by means of XRD, SEM, IR,TG, DTA and ICP methods- The unit cell for the product is hexagonal with the cell parame-ters a = 1.657 6nm and c= 1.186 5 nm. The volume of the cell is calculated to be 2. 823 3nm3. The product was decomposed into oxides from 310℃ to 390 ℃.