We carry out the first time-resolved measurement of Rb atoms desorbing from octadecyltrichlorosilane coated sur- faces by polarizing the atoms near the surface using an evanescent wave pump pulse and watching the subs...We carry out the first time-resolved measurement of Rb atoms desorbing from octadecyltrichlorosilane coated sur- faces by polarizing the atoms near the surface using an evanescent wave pump pulse and watching the subsequent intensity change of another evanescent wave probe beam, and find the mean adsorption （dwell） time to be about 400ns at a cell body temperature of 112℃. The adsorption energy is found to be 0.19eV from the surface tem- perature dependence of the adsorption time. This method can be extended to study the adsorption/desorption process of other alkali atoms on other surfaces of transparent substrates with an ultimate time resolution limited by the flight time of atoms in the evanescent wave which is of the order of nanoseconds.展开更多
The adsorption of decylmethylsulfoxide(DEMS)onto carbon black and the effects of temperature,salt(NaCl)and acid (HCl)have been measured.Typical two plateaux type adsorption isotherms were obtained.Applying the two ste...The adsorption of decylmethylsulfoxide(DEMS)onto carbon black and the effects of temperature,salt(NaCl)and acid (HCl)have been measured.Typical two plateaux type adsorption isotherms were obtained.Applying the two step model of surfactant adsorption on solid/liquld interface and the general adsorption isotherm equation[9]the experimental results were interpreted qualitatively and quantitatively.展开更多
It is indicative of the TSR result that CH4 was strongly adsorbed on well degassed SrCO3 surface at high temperatUre.A desorption peak of CH4 was found in CH4TPD profile which appeared at ca. 310℃.The strong adsorpti...It is indicative of the TSR result that CH4 was strongly adsorbed on well degassed SrCO3 surface at high temperatUre.A desorption peak of CH4 was found in CH4TPD profile which appeared at ca. 310℃.The strong adsorption of CH4 over the surface of SrCO3 was attributed to the strong basicity of SrO sites resulted from decomposition of SrCO_3展开更多
The phenomena of molecular adsorption in the nanometer are significant to the research of biological and medical materials, bio-medical engineering and other fields. As
The determination of trace rhenium(Ⅶ)by differential pulse polarography in the system of H_2SO_4-(NH_2OH)_2·H_2SO_4-TeO_4^(2-) is markedly improved by the addition of Nitron,which is adsorbed on the surface of m...The determination of trace rhenium(Ⅶ)by differential pulse polarography in the system of H_2SO_4-(NH_2OH)_2·H_2SO_4-TeO_4^(2-) is markedly improved by the addition of Nitron,which is adsorbed on the surface of mercury electrode.The limit of detection is down to 2×10^(-10) M.The adsorptive peak potential is -0.80V(vs.SCE).In the ranges of 5×10^(-10)-10^(-8),1×10^(-8)-10^(-7) and 1× 10^(-7)-10^(-6)M,there are good linear relationships between the peak current increment and the concentration,of which the relative standard deviations are 9.5,6.6,1.8% respectively with the correlation coefficients of linear regression of 0.995—0.999.The results relating to this polarographic wave show that it is an adsorption-catalytic wave.The mechanism of the electrode reaction is dis- cussed.展开更多
The isothermal adsorption of dyes on a variety of sisal based activated carbonfibers (SACFs), and the influence of PH and temperature on absorption are discussedin this paper The results indicate that the adsorption o...The isothermal adsorption of dyes on a variety of sisal based activated carbonfibers (SACFs), and the influence of PH and temperature on absorption are discussedin this paper The results indicate that the adsorption of methylene blue, crystal violetand Eriochrome blue black R on SACFs shows type I isotherms and can be describedby the Langnuir equation or the Freudlich equation. The acidity of solution hasgreatly ifluence over the adeorption amounts of methylene blue, crystal violet andEriochrome blue black R. As PHs of the solutions were adjusted to increase ordecrease from the original acidity of the solution (4. 7. 4. ) and 4. 0 for methylene blue,crystal violet and Eriochrome blue black R. respectively), the amounts of dyesadsorbed on SACFs increased. The adsorption temperature (in the range of 25~50℃)exerts little influence on the adsorption amount of methylene blue, crystal violet andfluorescein. For azo dyes (Eriochrome blue black R and Eriochrome black T), howeverthe absorption amount increases slightly with the elevation of temperature.展开更多
The equilibrium and kinetic characteristics of the adsorption of erythromycin to Sepabeads SP825 were determined.The equilibrium data in a batch system was well described by a Langmuir isotherm.The separation performa...The equilibrium and kinetic characteristics of the adsorption of erythromycin to Sepabeads SP825 were determined.The equilibrium data in a batch system was well described by a Langmuir isotherm.The separation performance was investigated in a fixed-bed system with respect to the adsorption superficial velocity,ionic strength and pH.A mathematical model was used to simulate the mass transfer mechanism,taking film mass transfer,pore diffusion and axial dispersion into account.The model predictions were consistent with the experi-mental data and were consequently used to determine the mass transfer coefficients.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11074050
文摘We carry out the first time-resolved measurement of Rb atoms desorbing from octadecyltrichlorosilane coated sur- faces by polarizing the atoms near the surface using an evanescent wave pump pulse and watching the subsequent intensity change of another evanescent wave probe beam, and find the mean adsorption （dwell） time to be about 400ns at a cell body temperature of 112℃. The adsorption energy is found to be 0.19eV from the surface tem- perature dependence of the adsorption time. This method can be extended to study the adsorption/desorption process of other alkali atoms on other surfaces of transparent substrates with an ultimate time resolution limited by the flight time of atoms in the evanescent wave which is of the order of nanoseconds.
文摘The adsorption of decylmethylsulfoxide(DEMS)onto carbon black and the effects of temperature,salt(NaCl)and acid (HCl)have been measured.Typical two plateaux type adsorption isotherms were obtained.Applying the two step model of surfactant adsorption on solid/liquld interface and the general adsorption isotherm equation[9]the experimental results were interpreted qualitatively and quantitatively.
文摘It is indicative of the TSR result that CH4 was strongly adsorbed on well degassed SrCO3 surface at high temperatUre.A desorption peak of CH4 was found in CH4TPD profile which appeared at ca. 310℃.The strong adsorption of CH4 over the surface of SrCO3 was attributed to the strong basicity of SrO sites resulted from decomposition of SrCO_3
文摘The phenomena of molecular adsorption in the nanometer are significant to the research of biological and medical materials, bio-medical engineering and other fields. As
文摘The determination of trace rhenium(Ⅶ)by differential pulse polarography in the system of H_2SO_4-(NH_2OH)_2·H_2SO_4-TeO_4^(2-) is markedly improved by the addition of Nitron,which is adsorbed on the surface of mercury electrode.The limit of detection is down to 2×10^(-10) M.The adsorptive peak potential is -0.80V(vs.SCE).In the ranges of 5×10^(-10)-10^(-8),1×10^(-8)-10^(-7) and 1× 10^(-7)-10^(-6)M,there are good linear relationships between the peak current increment and the concentration,of which the relative standard deviations are 9.5,6.6,1.8% respectively with the correlation coefficients of linear regression of 0.995—0.999.The results relating to this polarographic wave show that it is an adsorption-catalytic wave.The mechanism of the electrode reaction is dis- cussed.
文摘The isothermal adsorption of dyes on a variety of sisal based activated carbonfibers (SACFs), and the influence of PH and temperature on absorption are discussedin this paper The results indicate that the adsorption of methylene blue, crystal violetand Eriochrome blue black R on SACFs shows type I isotherms and can be describedby the Langnuir equation or the Freudlich equation. The acidity of solution hasgreatly ifluence over the adeorption amounts of methylene blue, crystal violet andEriochrome blue black R. As PHs of the solutions were adjusted to increase ordecrease from the original acidity of the solution (4. 7. 4. ) and 4. 0 for methylene blue,crystal violet and Eriochrome blue black R. respectively), the amounts of dyesadsorbed on SACFs increased. The adsorption temperature (in the range of 25~50℃)exerts little influence on the adsorption amount of methylene blue, crystal violet andfluorescein. For azo dyes (Eriochrome blue black R and Eriochrome black T), howeverthe absorption amount increases slightly with the elevation of temperature.
文摘The equilibrium and kinetic characteristics of the adsorption of erythromycin to Sepabeads SP825 were determined.The equilibrium data in a batch system was well described by a Langmuir isotherm.The separation performance was investigated in a fixed-bed system with respect to the adsorption superficial velocity,ionic strength and pH.A mathematical model was used to simulate the mass transfer mechanism,taking film mass transfer,pore diffusion and axial dispersion into account.The model predictions were consistent with the experi-mental data and were consequently used to determine the mass transfer coefficients.
