The feasibility and adsorption effect of lignite activated carbon for phenol removal from aqueous solutions were evaluated and investigated. A series of tests were performed to look into the influence of various exper...The feasibility and adsorption effect of lignite activated carbon for phenol removal from aqueous solutions were evaluated and investigated. A series of tests were performed to look into the influence of various experimental parameters such as contact time, initial phenol concentration, temperature, and pH value on the adsorption of phenol by lignite activated carbon. The experimental data were fitted well with the pseudo-second-order kinetic model. The adsorption is an endothermic process and conforms to Freundlich thermodynamic model. The results indicate that the lignite activated carbon is suitable to be used as an adsorbent material for adsorption of phenol from aqueous solutions.展开更多
This study is focused on the kinetic characteristics of photocatalytic degradation of gaseous organic compounds on modified titanium dioxide/activated carbon composite photocatalyst(MTA).The MTA,which co-doping with i...This study is focused on the kinetic characteristics of photocatalytic degradation of gaseous organic compounds on modified titanium dioxide/activated carbon composite photocatalyst(MTA).The MTA,which co-doping with iron(Fe) and nitrogen(N),was synthesized by a sol-gel method,and its photocatalytic performance was investigated under different reaction conditions.The experimental data obtained were tested by the zero,first and second order kinetic model,and the factors affecting the kinetic model were analyzed.It was clearly demonstrated that the experimental data of toluene and acetone on MTA fit quite well with second order kinetic model equation,but the experimental data of formaldehyde fits well with zero order kinetic model equation.展开更多
An isothermal operation is implemented by employing a thermogravimetric analyzer (TGA) for simulating the thermal decomposition behavior of 58μm pine sawdust in air atmosphere.An independent parallel reaction model i...An isothermal operation is implemented by employing a thermogravimetric analyzer (TGA) for simulating the thermal decomposition behavior of 58μm pine sawdust in air atmosphere.An independent parallel reaction model is adopted in this study to describe the thermal decomposition mechanism.The Weibull distribution function is used to record and analyze the weight loss during isothermal decomposition at different temperatures(500,600,700,and 800°C).The total weight loss of the pine sawdust is assumed as a linear combination of individual weight loss from three components,including the char and two volatile matters.The plot of the thermal decomposition rate curve leads to kinetic parameters such as the reaction rate constants and the reaction order.The results show that the Weibull distribution function successfully represents decomposition curves of three components,and fits the experimental data very well.Therefore,this study provides a simple way to evaluate the decomposition rate of biomass combustion in a real combustor.展开更多
Calcareous sand is a kind of special medium which is composed of calcium carbonate and other difficult soluble carbonate substances. Because of its rich in inner pore space and easy crashed,the mechanical property is ...Calcareous sand is a kind of special medium which is composed of calcium carbonate and other difficult soluble carbonate substances. Because of its rich in inner pore space and easy crashed,the mechanical property is very different from conventional quartz sand. Based on the compaction test and direct shear test of calcareous sand,by means of data fitting,the coupling relationship between compaction density and mechanical property under different water contents was obtained; meanwhile,the shear strength expression was built on the basis of the relationship between water content and dry density.展开更多
The effects of pulse ultrasound with different pulse parameters on the breakthrough curves of Geniposide on Resin 1300 were studied. The mass transfer model describing the adsorption process was constructed. Adsorptio...The effects of pulse ultrasound with different pulse parameters on the breakthrough curves of Geniposide on Resin 1300 were studied. The mass transfer model describing the adsorption process was constructed. Adsorption capability and the overall mass-transfer coefficient were obtained by fitting the constructed mass-transfer model and the experimental data. The effects of pulse ultrasound on adsorption of Geniposide on Resin1300 in a fixed bed were studied and compared. Amount of Geniposide adsorbed on Resin 1300 in the presence of ultrasound is lower than that in the absence of ultrasound, but the mass-transfer rate with ultrasonic irradiation is higher than that without ultrasound. Furthermore, mass transfer rate is enhanced by pulse modulation. In the conditions studied, the adsorption equilibrium constant decreases with increasing ultrasonic power, while the overall mass-transfer co-efficient increases. With increasing pulse duty ratio, adsorption equilibrium constant decreases initially, reaches a minimum when pulse duty ratio is 0.5, and then increases. On the contrary, the overall mass-transfer coefficient in-creases initially and reaches a maximum when pulse ratio is 0.5, and then decreases. Effects of pulse period on ad-sorption equilibrium and mass transfer rate reached the peak at pulse period of 28.6 ms.展开更多
In this paper, adsorption and regeneration characteristics of multi-walled carbon nanotubes （MWNTs） used as adsorbent were investigated for the removal of 1,3-beuzenediol （BDO） from water by the supercritieal wat...In this paper, adsorption and regeneration characteristics of multi-walled carbon nanotubes （MWNTs） used as adsorbent were investigated for the removal of 1,3-beuzenediol （BDO） from water by the supercritieal water （SCW） technique. FFIR, XPS, SEM and dispersion stability tests were used to characterize the structure and surface morphology of CNTs. The results showed that CNTs surfaces were slightly activated and strongly etched in supercritieal water system. The adsorption capacity of SCW-treated CNTs was higher than that of raw CNTs. The adsorbed amounts for treated CNTs and raw CNTs samples at the same initial concentration of 60 mg/L were ca. 16.42 and 7.30 mg/g, respectively. The BDO adsorption of treated CNTs was due to the physical adsorption. The experimental data fit Freundlich isotherm model better than Langmuir one. The loaded adsorbent could be efficiently desorbed and regenerated by SCW technique. Therefore, SCW is a promising and environmentally friendly technique for the improvement of adsorption and regeneration of CNTs.展开更多
Extensive testing was carried out to study the effects of rare earth Ce doping on the properties of SnAgCu solder alloys.The addition of 0.03%(mass fraction) rare earth Ce into SnAgCu solder may improve its mechanical...Extensive testing was carried out to study the effects of rare earth Ce doping on the properties of SnAgCu solder alloys.The addition of 0.03%(mass fraction) rare earth Ce into SnAgCu solder may improve its mechanical properties,but slightly lower its melting temperature.The tensile creep behavior of bulk SnAgCuCe solders was reported and compared with SnAgCu solders.It is found that SnAgCuCe solders show higher creep resistance than SnAgCu alloys.Moreover,Dorn model and Garofalo model are successfully used to describe the creep behavior of SnAgCu and SnAgCuCe alloys.The parameters of the two creep constitutive equations for SnAgCu and SnAgCuCe solders are determined from separated constitutive relations and experimental results.Nonlinear least-squares fitting is selected to determine the model constants.The experimental data of the stress-creep strain rate curves are in good agreement with the theoretical ones.展开更多
The adsorption of Ca（ II ） ions from aqueous solution by ehitosan a-ketoglutaric acid （KCTS） and hydroxamated chitosan a-ketoglutaric acid （HKCTS） was studied in a batch adsorption system. The Langmuir and Freun...The adsorption of Ca（ II ） ions from aqueous solution by ehitosan a-ketoglutaric acid （KCTS） and hydroxamated chitosan a-ketoglutaric acid （HKCTS） was studied in a batch adsorption system. The Langmuir and Freundlich adsorption models were applied to describing the equilibrium isotherms, and isotherm constants were determined. The kinetics of the adsorption with respect to the initial Ca（II） ions concentration, temperature and pH was investigated. The pseudo-first-order and second-order kinetic models were used to describe the kinetic data and the rate constants were evaluated. The results show that the experimental data fit well to the Langmuir isotherms with a high correlation coefficient （R2）. The pseudo-second-order rate expression provides the best fitting kinetic model. The pseudo second-order kinetic model is indicated with the activation energy of 26.22 kJ/mol and 6.16 kJ/mol for KCTS and HKCTS, respectively. It is suggested that the overall rate of adsorption of Ca（ II ） ions is likely to be controlled by the chemical process.展开更多
In this paper, the high speed tension experiments have been performed on ultra high strength bulletproof steel. The specimen were cut from B-grade bulletproof steel sheet after hard-module quenching with thickness of ...In this paper, the high speed tension experiments have been performed on ultra high strength bulletproof steel. The specimen were cut from B-grade bulletproof steel sheet after hard-module quenching with thickness of 2.3 mm. The mechanical properties at strain rates of 0.001 s^-1, 0.01 s^-1, 0.1 s^-1 and 1 s^-1 were carried out on MTSS10, while those at higher strain rates of 200 s^-1, 500 s^-1 and i 000 s^-1 were tested on HTM5020 high speed tension tester and Hopkinson bar. The data from the high speed tension experiments were fitted via Johnson-Cook constitutive equation, and the fracture surface of each specimen was analyzed by scanning electron microscope （SEM）. The results indicate that, the shoot resistance capability of bulletproof steel is closely related to its strength, thickness and flow behaviors under high strain rate. The shoot resistance will be improved in the case of higher strength and better matching between strength and elongation. The Johnson-Cook constitutive equation fitted via experimental data provides fundament to numerical simulation. With the increase of strain rate, the size and depth of dimple trend to decrease and the depth of dimple changes less in steel with lower strength and higher elongation. The SEM analysis of fracture aspect is of benefit for further understanding of deformation and fracture mode under high strain rate.展开更多
基金Supported by the Fundamental Research Funds for the Central Universities (2010ZY42)the Open Foundation of National Laboratory of Mineral Materials of China University of Geosciences (08A003)
文摘The feasibility and adsorption effect of lignite activated carbon for phenol removal from aqueous solutions were evaluated and investigated. A series of tests were performed to look into the influence of various experimental parameters such as contact time, initial phenol concentration, temperature, and pH value on the adsorption of phenol by lignite activated carbon. The experimental data were fitted well with the pseudo-second-order kinetic model. The adsorption is an endothermic process and conforms to Freundlich thermodynamic model. The results indicate that the lignite activated carbon is suitable to be used as an adsorbent material for adsorption of phenol from aqueous solutions.
基金Supported by the Natural Science Foundation of Guangdong Province,China(8151064101000049)
文摘This study is focused on the kinetic characteristics of photocatalytic degradation of gaseous organic compounds on modified titanium dioxide/activated carbon composite photocatalyst(MTA).The MTA,which co-doping with iron(Fe) and nitrogen(N),was synthesized by a sol-gel method,and its photocatalytic performance was investigated under different reaction conditions.The experimental data obtained were tested by the zero,first and second order kinetic model,and the factors affecting the kinetic model were analyzed.It was clearly demonstrated that the experimental data of toluene and acetone on MTA fit quite well with second order kinetic model equation,but the experimental data of formaldehyde fits well with zero order kinetic model equation.
基金Supported by the Chung Yuan Christian University (CYCU-97-CR-CE)
文摘An isothermal operation is implemented by employing a thermogravimetric analyzer (TGA) for simulating the thermal decomposition behavior of 58μm pine sawdust in air atmosphere.An independent parallel reaction model is adopted in this study to describe the thermal decomposition mechanism.The Weibull distribution function is used to record and analyze the weight loss during isothermal decomposition at different temperatures(500,600,700,and 800°C).The total weight loss of the pine sawdust is assumed as a linear combination of individual weight loss from three components,including the char and two volatile matters.The plot of the thermal decomposition rate curve leads to kinetic parameters such as the reaction rate constants and the reaction order.The results show that the Weibull distribution function successfully represents decomposition curves of three components,and fits the experimental data very well.Therefore,this study provides a simple way to evaluate the decomposition rate of biomass combustion in a real combustor.
文摘Calcareous sand is a kind of special medium which is composed of calcium carbonate and other difficult soluble carbonate substances. Because of its rich in inner pore space and easy crashed,the mechanical property is very different from conventional quartz sand. Based on the compaction test and direct shear test of calcareous sand,by means of data fitting,the coupling relationship between compaction density and mechanical property under different water contents was obtained; meanwhile,the shear strength expression was built on the basis of the relationship between water content and dry density.
基金Supported by the National lqatural Science Foundation of China （20346003）.
文摘The effects of pulse ultrasound with different pulse parameters on the breakthrough curves of Geniposide on Resin 1300 were studied. The mass transfer model describing the adsorption process was constructed. Adsorption capability and the overall mass-transfer coefficient were obtained by fitting the constructed mass-transfer model and the experimental data. The effects of pulse ultrasound on adsorption of Geniposide on Resin1300 in a fixed bed were studied and compared. Amount of Geniposide adsorbed on Resin 1300 in the presence of ultrasound is lower than that in the absence of ultrasound, but the mass-transfer rate with ultrasonic irradiation is higher than that without ultrasound. Furthermore, mass transfer rate is enhanced by pulse modulation. In the conditions studied, the adsorption equilibrium constant decreases with increasing ultrasonic power, while the overall mass-transfer co-efficient increases. With increasing pulse duty ratio, adsorption equilibrium constant decreases initially, reaches a minimum when pulse duty ratio is 0.5, and then increases. On the contrary, the overall mass-transfer coefficient in-creases initially and reaches a maximum when pulse ratio is 0.5, and then decreases. Effects of pulse period on ad-sorption equilibrium and mass transfer rate reached the peak at pulse period of 28.6 ms.
基金Sponsored by the Project from Natural Scientific Research Innovation Foundation in Harbin Institute of Technology(Grant No. HIT.NSRIF.2008.05)
文摘In this paper, adsorption and regeneration characteristics of multi-walled carbon nanotubes （MWNTs） used as adsorbent were investigated for the removal of 1,3-beuzenediol （BDO） from water by the supercritieal water （SCW） technique. FFIR, XPS, SEM and dispersion stability tests were used to characterize the structure and surface morphology of CNTs. The results showed that CNTs surfaces were slightly activated and strongly etched in supercritieal water system. The adsorption capacity of SCW-treated CNTs was higher than that of raw CNTs. The adsorbed amounts for treated CNTs and raw CNTs samples at the same initial concentration of 60 mg/L were ca. 16.42 and 7.30 mg/g, respectively. The BDO adsorption of treated CNTs was due to the physical adsorption. The experimental data fit Freundlich isotherm model better than Langmuir one. The loaded adsorbent could be efficiently desorbed and regenerated by SCW technique. Therefore, SCW is a promising and environmentally friendly technique for the improvement of adsorption and regeneration of CNTs.
基金Project(BCXJ09-07) supported by Doctoral Dissertation Innovation and Excellence Producing Foundation of Nanjing University of Aeronautics and Astronautics,ChinaProject(CX07B_087z) supported by the Jiangsu General Colleges and Universities Postgraduate Scientific Research Innovative Plan,China
文摘Extensive testing was carried out to study the effects of rare earth Ce doping on the properties of SnAgCu solder alloys.The addition of 0.03%(mass fraction) rare earth Ce into SnAgCu solder may improve its mechanical properties,but slightly lower its melting temperature.The tensile creep behavior of bulk SnAgCuCe solders was reported and compared with SnAgCu solders.It is found that SnAgCuCe solders show higher creep resistance than SnAgCu alloys.Moreover,Dorn model and Garofalo model are successfully used to describe the creep behavior of SnAgCu and SnAgCuCe alloys.The parameters of the two creep constitutive equations for SnAgCu and SnAgCuCe solders are determined from separated constitutive relations and experimental results.Nonlinear least-squares fitting is selected to determine the model constants.The experimental data of the stress-creep strain rate curves are in good agreement with the theoretical ones.
基金Project(20376085) supported by the National Natural Science Foundation of China
文摘The adsorption of Ca（ II ） ions from aqueous solution by ehitosan a-ketoglutaric acid （KCTS） and hydroxamated chitosan a-ketoglutaric acid （HKCTS） was studied in a batch adsorption system. The Langmuir and Freundlich adsorption models were applied to describing the equilibrium isotherms, and isotherm constants were determined. The kinetics of the adsorption with respect to the initial Ca（II） ions concentration, temperature and pH was investigated. The pseudo-first-order and second-order kinetic models were used to describe the kinetic data and the rate constants were evaluated. The results show that the experimental data fit well to the Langmuir isotherms with a high correlation coefficient （R2）. The pseudo-second-order rate expression provides the best fitting kinetic model. The pseudo second-order kinetic model is indicated with the activation energy of 26.22 kJ/mol and 6.16 kJ/mol for KCTS and HKCTS, respectively. It is suggested that the overall rate of adsorption of Ca（ II ） ions is likely to be controlled by the chemical process.
文摘In this paper, the high speed tension experiments have been performed on ultra high strength bulletproof steel. The specimen were cut from B-grade bulletproof steel sheet after hard-module quenching with thickness of 2.3 mm. The mechanical properties at strain rates of 0.001 s^-1, 0.01 s^-1, 0.1 s^-1 and 1 s^-1 were carried out on MTSS10, while those at higher strain rates of 200 s^-1, 500 s^-1 and i 000 s^-1 were tested on HTM5020 high speed tension tester and Hopkinson bar. The data from the high speed tension experiments were fitted via Johnson-Cook constitutive equation, and the fracture surface of each specimen was analyzed by scanning electron microscope （SEM）. The results indicate that, the shoot resistance capability of bulletproof steel is closely related to its strength, thickness and flow behaviors under high strain rate. The shoot resistance will be improved in the case of higher strength and better matching between strength and elongation. The Johnson-Cook constitutive equation fitted via experimental data provides fundament to numerical simulation. With the increase of strain rate, the size and depth of dimple trend to decrease and the depth of dimple changes less in steel with lower strength and higher elongation. The SEM analysis of fracture aspect is of benefit for further understanding of deformation and fracture mode under high strain rate.
