Long-column method was used to determine the adsorption isotherms of 4 VOCs (benzene, toluene, chloroform and acetone) in concentration range of 250～5000?mg·m -3 on a commercial activated-carbon under different ...Long-column method was used to determine the adsorption isotherms of 4 VOCs (benzene, toluene, chloroform and acetone) in concentration range of 250～5000?mg·m -3 on a commercial activated-carbon under different humidity levels at 30?℃.A modified Polanyi-Dubinin equation was proposed to correlate the adsorption equilibrium of different VOC-water vapor systems. Among 3 methods of calculating the Relative Affinity Coefficient β used,the Molar Volume method and the Molecular Parachor method proved to be suitable for the calculation with better precision than the Electronic Polarization method. Calculation results were satisfactory for the benzene-, toluene-, and chloroform-water vapor/activated carbon systems, but poor for acetone possibly because of its strong polarity.The equation could be used to estimate the detaining effect of atmospheric humidity on the adsorption equilibrium of VOCs on activated carbon.展开更多
It is generally acknowledged in heterogeneous catalysis that hydrogenation follows the so-called Horiuti-Polanyi(HP) mechanism. In this work, a thorough investigation of the mechanism of hydrogenation of hydroxyl grou...It is generally acknowledged in heterogeneous catalysis that hydrogenation follows the so-called Horiuti-Polanyi(HP) mechanism. In this work, a thorough investigation of the mechanism of hydrogenation of hydroxyl groups and O catalyzed by a series of transition metals was carried out through density functional theory calculations, as surface hydroxyls and O are very common species in many catalytic systems. It is found that different metal catalysts exhibit different mechanisms. On some metal catalysts, the non-HP mechanism is preferred, whereas the classic HP mechanism is favored on other catalysts. Detailed analyses of the metal-dependent mechanism shows that the activity toward the dissociation of H2 decides which mechanism is preferred. On active catalysts, such as Ni and Pt, H2 prefers to dissociate with strong H adsorption energies, which lead to the classic HP mechanism being favored. On inactive surfaces, on the other hand, the adsorption of H is weak, which results in the non-HP mechanism being preferred. The parameter η, which is a structural descriptor, was defined to understand the different mechanisms.展开更多
Is there a national philosophy?It is hard to answer the question definitively,beyond mainstream philosophical currents and a supposed particular tradition.Beyond an invisible boundary,today,academic research is also d...Is there a national philosophy?It is hard to answer the question definitively,beyond mainstream philosophical currents and a supposed particular tradition.Beyond an invisible boundary,today,academic research is also defined by its international and interdisciplinary dimension.Although it is possible to argue about certain specificities,the interaction between different national traditions and distant scientific areas can be fruitful(and these parameters are also required in the case of research funding).One can take an example of the reception of Michael Polanyi’s epistemology in Italy,starting from a brief reference to the Italian tradition and its renewed interest thanks to the Italian Thought.Therefore,in this paper,I will try to consider Polanyi’s epistemology through his relations with Italian intellectuals and the dissemination of his writings in Italy.In the end,I will verify the potential contribution of Polanyian personal epistemology in three philosophical and social issues addressed in Italy.展开更多
In this research,static adsorption of three polycyclic aromatic hydrocarbons(PAHs),naphthalene,acenaphthene,and fluorene,from aqueous solutions onto hypercrosslinked polymeric adsorbent within the temperature range of...In this research,static adsorption of three polycyclic aromatic hydrocarbons(PAHs),naphthalene,acenaphthene,and fluorene,from aqueous solutions onto hypercrosslinked polymeric adsorbent within the temperature range of 288-308 K is investigated.Several isotherm equations are correlated with the equilibrium data,and the experimental data is found to fit the Polanyi-Dubinin-Manes model best within the entire range of concentrations,providing evidence that pore-filling is the dominating sorption mechanism for PAHs.The study shows that the molecular size of adsorbates has distinct in-fluence on adsorption capacity of hypercrosslinked polymeric adsorbent for the PAHs;the larger the adsorbate molecular size,the lower the adsorption equilibrium capacity.Based on the Polanyi-Dubinin-Manes model,the molecular size of adsorbates was introduced to adjust the adsorbate molar volume.Plots of qv vs.(σε /Vs) are collapsed to a single correlation curve for different adsorbates on hypercrosslinked polymeric resin.展开更多
文摘Long-column method was used to determine the adsorption isotherms of 4 VOCs (benzene, toluene, chloroform and acetone) in concentration range of 250～5000?mg·m -3 on a commercial activated-carbon under different humidity levels at 30?℃.A modified Polanyi-Dubinin equation was proposed to correlate the adsorption equilibrium of different VOC-water vapor systems. Among 3 methods of calculating the Relative Affinity Coefficient β used,the Molar Volume method and the Molecular Parachor method proved to be suitable for the calculation with better precision than the Electronic Polarization method. Calculation results were satisfactory for the benzene-, toluene-, and chloroform-water vapor/activated carbon systems, but poor for acetone possibly because of its strong polarity.The equation could be used to estimate the detaining effect of atmospheric humidity on the adsorption equilibrium of VOCs on activated carbon.
基金supported by the National Natural Science Foundation of China(21673072,21333003,and 91845111)~~
文摘It is generally acknowledged in heterogeneous catalysis that hydrogenation follows the so-called Horiuti-Polanyi(HP) mechanism. In this work, a thorough investigation of the mechanism of hydrogenation of hydroxyl groups and O catalyzed by a series of transition metals was carried out through density functional theory calculations, as surface hydroxyls and O are very common species in many catalytic systems. It is found that different metal catalysts exhibit different mechanisms. On some metal catalysts, the non-HP mechanism is preferred, whereas the classic HP mechanism is favored on other catalysts. Detailed analyses of the metal-dependent mechanism shows that the activity toward the dissociation of H2 decides which mechanism is preferred. On active catalysts, such as Ni and Pt, H2 prefers to dissociate with strong H adsorption energies, which lead to the classic HP mechanism being favored. On inactive surfaces, on the other hand, the adsorption of H is weak, which results in the non-HP mechanism being preferred. The parameter η, which is a structural descriptor, was defined to understand the different mechanisms.
文摘Is there a national philosophy?It is hard to answer the question definitively,beyond mainstream philosophical currents and a supposed particular tradition.Beyond an invisible boundary,today,academic research is also defined by its international and interdisciplinary dimension.Although it is possible to argue about certain specificities,the interaction between different national traditions and distant scientific areas can be fruitful(and these parameters are also required in the case of research funding).One can take an example of the reception of Michael Polanyi’s epistemology in Italy,starting from a brief reference to the Italian tradition and its renewed interest thanks to the Italian Thought.Therefore,in this paper,I will try to consider Polanyi’s epistemology through his relations with Italian intellectuals and the dissemination of his writings in Italy.In the end,I will verify the potential contribution of Polanyian personal epistemology in three philosophical and social issues addressed in Italy.
基金the National Natural Science Foundation of China(Grant No.50408025)
文摘In this research,static adsorption of three polycyclic aromatic hydrocarbons(PAHs),naphthalene,acenaphthene,and fluorene,from aqueous solutions onto hypercrosslinked polymeric adsorbent within the temperature range of 288-308 K is investigated.Several isotherm equations are correlated with the equilibrium data,and the experimental data is found to fit the Polanyi-Dubinin-Manes model best within the entire range of concentrations,providing evidence that pore-filling is the dominating sorption mechanism for PAHs.The study shows that the molecular size of adsorbates has distinct in-fluence on adsorption capacity of hypercrosslinked polymeric adsorbent for the PAHs;the larger the adsorbate molecular size,the lower the adsorption equilibrium capacity.Based on the Polanyi-Dubinin-Manes model,the molecular size of adsorbates was introduced to adjust the adsorbate molar volume.Plots of qv vs.(σε /Vs) are collapsed to a single correlation curve for different adsorbates on hypercrosslinked polymeric resin.
