The FT-IR difference spectroscopy and the Raman spectroscopy were used to ide ntify the polyborate ions in saturated aqueous solutions during dissolution and transformation of 2MgO·2B2O3·MgCl2·14H2O in ...The FT-IR difference spectroscopy and the Raman spectroscopy were used to ide ntify the polyborate ions in saturated aqueous solutions during dissolution and transformation of 2MgO·2B2O3·MgCl2·14H2O in different HCl solutions at 30℃. The assignments of the recorded IR-Spectroscopic frequencies and Raman shift of the borate aqueous solution are given. The existing forms of polyborate anions in saturated aqueous solution and their interaction have been discussed. The rel ationships between the existing forms of polyborate anions and the crystallizing solid phases have been gained.展开更多
1 INTRODUCTIONThe concentration distribution of reactant in porouscatalyst pellet not only is the basis of calculating theeffectiveness factor,but also has a great significancein investigating the reaction and mass tr...1 INTRODUCTIONThe concentration distribution of reactant in porouscatalyst pellet not only is the basis of calculating theeffectiveness factor,but also has a great significancein investigating the reaction and mass transfer in thecatalyst pellet.In principle,the concentration distri-bution and the effectiveness factor of a catalyst pelletcan be obtained by solving the reaction-diffusion equation.However,most of the differential equations haveno analytical solution except for some simple cases.The previous investigators have made great efforts to calculate the effectiveness factors of catalysts.They first obtained asymptotic solutions of effective-ness factor in the cases of the Thiele modulus φ→Oand φ→oo by means of perturbation method,thensynthesized the information of the asymptotic solu-展开更多
文摘The FT-IR difference spectroscopy and the Raman spectroscopy were used to ide ntify the polyborate ions in saturated aqueous solutions during dissolution and transformation of 2MgO·2B2O3·MgCl2·14H2O in different HCl solutions at 30℃. The assignments of the recorded IR-Spectroscopic frequencies and Raman shift of the borate aqueous solution are given. The existing forms of polyborate anions in saturated aqueous solution and their interaction have been discussed. The rel ationships between the existing forms of polyborate anions and the crystallizing solid phases have been gained.
基金Supported by the Natural Science Foundation of Fujian Province.
文摘1 INTRODUCTIONThe concentration distribution of reactant in porouscatalyst pellet not only is the basis of calculating theeffectiveness factor,but also has a great significancein investigating the reaction and mass transfer in thecatalyst pellet.In principle,the concentration distri-bution and the effectiveness factor of a catalyst pelletcan be obtained by solving the reaction-diffusion equation.However,most of the differential equations haveno analytical solution except for some simple cases.The previous investigators have made great efforts to calculate the effectiveness factors of catalysts.They first obtained asymptotic solutions of effective-ness factor in the cases of the Thiele modulus φ→Oand φ→oo by means of perturbation method,thensynthesized the information of the asymptotic solu-
