The recent works on the development of computational mass transfer （CMT） method and its applications in chemical process simulation are reviewed. Some development strategies and challenges in future research are als...The recent works on the development of computational mass transfer （CMT） method and its applications in chemical process simulation are reviewed. Some development strategies and challenges in future research are also discussed.展开更多
A computational mass transfer model is proposed for predicting the concentration profile and Murphree efficiency of sieve tray distillation column. The proposed model is based on using modified c＇2 -εc＇ two equatio...A computational mass transfer model is proposed for predicting the concentration profile and Murphree efficiency of sieve tray distillation column. The proposed model is based on using modified c＇2 -εc＇ two equations formulation for closing the differential turbulent mass transfer equation with improvement by considering the vapor injected from the sieve hole to be three dimensional. The predicted concentration distributions by using proposed model were checked by experimental work conducted on a sieve tray simulator of 1.2 meters in diameter for desorbing the dissolved oxygen in the feed water by blowing air. The model predictions were confirmed by the experimental measurement. The validation of the proposed model was further tested by comparing the simulated result with the performance of an industrial scale sieve tray distillation column reported by Kunesh et al. for the stripping of toluene from its water solution. The predicted outlet concentration of each tray and the Murphree tray efficiencies under different operating conditions were in agreement with the published data. The simulated turbulent mass transfer diffusivity on each tray was within the range of the experimental result in the same sieve column reported by Cai et al. In addition, the prediction of the influence of sieve tray structure on the tray efficiency by using the proposed model was demonstrated.展开更多
Simulations of adsorption process using the Reynolds mass flux model described in Part I of these serial articles are presented. The object of the simulation is the methylene chloride adsorption in a packed column(0.0...Simulations of adsorption process using the Reynolds mass flux model described in Part I of these serial articles are presented. The object of the simulation is the methylene chloride adsorption in a packed column(0.041 m id,packed with spherical activated carbon up to a length of 0.2 m). With the Reynolds mass flux model,breakthrough/regeneration curves, concentration and temperature as well as the velocity distributions can be obtained. The simulated results are compared with the experimental data reported in the literature and satisfactory agreement is found both in breakthrough/regeneration curves and temperature curves. Moreover,the anisotropic turbulent mass diffusion is characterized and discussed.展开更多
Using panel data of 29 regions in China from 1999 to 2007, this paper presents a systematic evaluation of how FDI＇s spillover effects impact the quality of China＇s indigenous econotnic growth, Research outcomes sugg...Using panel data of 29 regions in China from 1999 to 2007, this paper presents a systematic evaluation of how FDI＇s spillover effects impact the quality of China＇s indigenous econotnic growth, Research outcomes suggest that technology transfers and diffusion have a positive effect on indigenous growth quality. Spitlover effects （mainly competition effect） have primarily negatively affected indigenous growth quality. The effect on indigenous growth quality is positive only in sub-samples with high foreign capital concentration and ,,hen the spillover effect is similar to the technology transfer and diffusion effect brought about by localization. It is also found that technology gaps, foreign capital concentration and value added ratio gaps are important factors affecting the impact of technology transfer and diffusion on indigenous economic growth.展开更多
A class of one-way isothermal mass transfer processes with Fick’s diffusive mass transfer law[g ∝Δ(c)]is investigated in this paper.Based on the definition of the mass entransy,the entransy dissipation function whi...A class of one-way isothermal mass transfer processes with Fick’s diffusive mass transfer law[g ∝Δ(c)]is investigated in this paper.Based on the definition of the mass entransy,the entransy dissipation function which reflects the irreversibility of mass transfer ability loss is derived.The optimal concentration allocations of the key components corresponding to the highand low-concentration sides for the minimum entransy dissipation of the mass transfer process are obtained by applying opti- mal control theory and compared with the strategies of the minimum entropy generation,constant mass transfer flux(constant concentration difference),and constant concentration ratio(constant chemical potential difference).The results are as follows. For the optimal mass transfer strategy of the minimum entransy dissipation,the product of the square of the key component concentration difference between the high-and the low-concentration sides and the inert component concentration at the low-concentration side is a constant,while for that of the minimum entropy generation,the ratio of the square of the key com-ponent concentration difference between the high-and the low-concentration sides to the key component concentration at the low-concentration side is a constant;when the mass transfer process is not involved in energy conversion process,the optimi-zation principle should be the minimum entransy dissipation;the mass transfer strategy of constant concentration difference is superior to that of constant concentration ratio.The results obtained in this paper can provide some theoretical guidelines for optimal designs and operations of practical mass transfer processes.展开更多
There is considerable interest in using ionic liquids(ILs) as protic electrolytes. However, the reported proton transfer rate in ILs is quite slow. In this study, we report functionalizing imidazolium ILs with alcohol...There is considerable interest in using ionic liquids(ILs) as protic electrolytes. However, the reported proton transfer rate in ILs is quite slow. In this study, we report functionalizing imidazolium ILs with alcohol hydroxyls, aiming at constructing hydrogen bonding networks in the electrolyte, can stimulate fast proton hopping transfer. For demonstration, the diffusion of proton and Cl. in 1-(3-hydroxypropyl)-3-methylimidazolium tetrafluoroboride(C_3OHmimBF_4) were studied using cyclic voltammetry and potentiostatic method at 30 °C. The diffusion coefficient of proton is about one order of magnitude higher than that of Cl. in the same electrolyte, and about 5 times that of proton in the non-hydydroxyl 1-(butyl)-3-methylimidazolium tetrafluoroboride(BmimBF_4) when normalized to the diffusion coefficients of Cl. in respective ILs. In the meantime, 1H NMR spectra revealed a strong hydrogen bonding interaction between proton and C_3OHmimBF_4 which is absent between proton and BmimBF_4, thus the significantly higher diffusion coefficient of proton in C_3OHmimBF_4 may suggest the formation of effective hydrogen bonding networks, enabling rapid proton hopping via the Grotthuss mechanism.展开更多
Mass transfer between a bubble and the dense phase in gas fluidized beds of Group A and Group B particles was proposed based on previous experimental results and literature data. The mass transfer coefficient between ...Mass transfer between a bubble and the dense phase in gas fluidized beds of Group A and Group B particles was proposed based on previous experimental results and literature data. The mass transfer coefficient between bubbles and the dense phase was determined by kbe = 0.21 db. A theoretical analysis of the mass transfer coefficient between a bubble and the dense phase using diffusion equations showed that the mass transfer coefficient between a bubble and the dense phase is kbe α εmf√ub/db in both three- and two-dimensional fiuidized beds. An effective diffusion coefficient in gas fluidized beds was introduced and correlated with bubble size as De = 13.3db2.7 for Group A and Group B particles. The mass transfer coefficient kbe can then be expressed as kbe = 0.492εmf√ubdb1.7 for bubbles in a three-dimensional bed and kbe = 0.576εm√ubdb1.7 for bubbles in a two-dimensional bed.展开更多
Twelve volunteers with normal hearing (9 males and 3 females) participated in this work The sound transfer functions (STFS) from diffuse sound field to the subject's eardrums were measured and correlated...Twelve volunteers with normal hearing (9 males and 3 females) participated in this work The sound transfer functions (STFS) from diffuse sound field to the subject's eardrums were measured and correlated to the temporary threshold shift (TTS) due to fiffuse-exposure.A probe tube with a miniature microphone was used for STF measurements in which successive 1/3 oct bandwidth random noise with central frequency from 0.25 kKz to 8 kHz were used. The subjects were divided into two groups, with the STF maxima at 2 kHz and 4 kHz respectively Pre- and post- exposure sweep Bekesy audiograms were recorded and the temporary thresh old shift calctilated as the difference between the two. Frequency of the maximum TTS was correlated to that of the maximum STF. The average TTS was very small or zero at frequen cies below the band noise exposure , but was noticeable even at the highest measured frequency (8 kHz) for beyond the noise band. Also individual differences in STF were found at frequencies between 2 kHz and 4 kHz展开更多
基金Supported by the National Science Foundation of China（20736005）.ACKNOWLEDGEMENTSThe authors acknowledge the assistance from thestaff in the State Key Laboratories of Chemical Engineering （Tianjin University）.
文摘The recent works on the development of computational mass transfer （CMT） method and its applications in chemical process simulation are reviewed. Some development strategies and challenges in future research are also discussed.
基金Supported by the National lqatural Science Foundation of China （20736005）.
文摘A computational mass transfer model is proposed for predicting the concentration profile and Murphree efficiency of sieve tray distillation column. The proposed model is based on using modified c＇2 -εc＇ two equations formulation for closing the differential turbulent mass transfer equation with improvement by considering the vapor injected from the sieve hole to be three dimensional. The predicted concentration distributions by using proposed model were checked by experimental work conducted on a sieve tray simulator of 1.2 meters in diameter for desorbing the dissolved oxygen in the feed water by blowing air. The model predictions were confirmed by the experimental measurement. The validation of the proposed model was further tested by comparing the simulated result with the performance of an industrial scale sieve tray distillation column reported by Kunesh et al. for the stripping of toluene from its water solution. The predicted outlet concentration of each tray and the Murphree tray efficiencies under different operating conditions were in agreement with the published data. The simulated turbulent mass transfer diffusivity on each tray was within the range of the experimental result in the same sieve column reported by Cai et al. In addition, the prediction of the influence of sieve tray structure on the tray efficiency by using the proposed model was demonstrated.
基金Supported by the National Natural Science Foundation of China(21376163)
文摘Simulations of adsorption process using the Reynolds mass flux model described in Part I of these serial articles are presented. The object of the simulation is the methylene chloride adsorption in a packed column(0.041 m id,packed with spherical activated carbon up to a length of 0.2 m). With the Reynolds mass flux model,breakthrough/regeneration curves, concentration and temperature as well as the velocity distributions can be obtained. The simulated results are compared with the experimental data reported in the literature and satisfactory agreement is found both in breakthrough/regeneration curves and temperature curves. Moreover,the anisotropic turbulent mass diffusion is characterized and discussed.
文摘Using panel data of 29 regions in China from 1999 to 2007, this paper presents a systematic evaluation of how FDI＇s spillover effects impact the quality of China＇s indigenous econotnic growth, Research outcomes suggest that technology transfers and diffusion have a positive effect on indigenous growth quality. Spitlover effects （mainly competition effect） have primarily negatively affected indigenous growth quality. The effect on indigenous growth quality is positive only in sub-samples with high foreign capital concentration and ,,hen the spillover effect is similar to the technology transfer and diffusion effect brought about by localization. It is also found that technology gaps, foreign capital concentration and value added ratio gaps are important factors affecting the impact of technology transfer and diffusion on indigenous economic growth.
基金supported by the National Natural Science Foundation of China(Grant No.10905093)the Program for New Century Excellent Talents in University of China(Grant No.NCET-04-1006)the Foun-dation for the Author of National Excellent Doctoral Dissertation of China(Grant No.200136)
文摘A class of one-way isothermal mass transfer processes with Fick’s diffusive mass transfer law[g ∝Δ(c)]is investigated in this paper.Based on the definition of the mass entransy,the entransy dissipation function which reflects the irreversibility of mass transfer ability loss is derived.The optimal concentration allocations of the key components corresponding to the highand low-concentration sides for the minimum entransy dissipation of the mass transfer process are obtained by applying opti- mal control theory and compared with the strategies of the minimum entropy generation,constant mass transfer flux(constant concentration difference),and constant concentration ratio(constant chemical potential difference).The results are as follows. For the optimal mass transfer strategy of the minimum entransy dissipation,the product of the square of the key component concentration difference between the high-and the low-concentration sides and the inert component concentration at the low-concentration side is a constant,while for that of the minimum entropy generation,the ratio of the square of the key com-ponent concentration difference between the high-and the low-concentration sides to the key component concentration at the low-concentration side is a constant;when the mass transfer process is not involved in energy conversion process,the optimi-zation principle should be the minimum entransy dissipation;the mass transfer strategy of constant concentration difference is superior to that of constant concentration ratio.The results obtained in this paper can provide some theoretical guidelines for optimal designs and operations of practical mass transfer processes.
基金supported by the National Natural Science Foundation of China(21173161,21673164)the Large-scale Instrument and Equipment Sharing Foundation of Wuhan University
文摘There is considerable interest in using ionic liquids(ILs) as protic electrolytes. However, the reported proton transfer rate in ILs is quite slow. In this study, we report functionalizing imidazolium ILs with alcohol hydroxyls, aiming at constructing hydrogen bonding networks in the electrolyte, can stimulate fast proton hopping transfer. For demonstration, the diffusion of proton and Cl. in 1-(3-hydroxypropyl)-3-methylimidazolium tetrafluoroboride(C_3OHmimBF_4) were studied using cyclic voltammetry and potentiostatic method at 30 °C. The diffusion coefficient of proton is about one order of magnitude higher than that of Cl. in the same electrolyte, and about 5 times that of proton in the non-hydydroxyl 1-(butyl)-3-methylimidazolium tetrafluoroboride(BmimBF_4) when normalized to the diffusion coefficients of Cl. in respective ILs. In the meantime, 1H NMR spectra revealed a strong hydrogen bonding interaction between proton and C_3OHmimBF_4 which is absent between proton and BmimBF_4, thus the significantly higher diffusion coefficient of proton in C_3OHmimBF_4 may suggest the formation of effective hydrogen bonding networks, enabling rapid proton hopping via the Grotthuss mechanism.
基金an innovation research grant(13YZ130)a Leading Academic Discipline Project(J51803)from the Shanghai Education Committeea Cultivate Discipline Fund of the Shanghai Second Polytechnic University(XXKPY1303)
文摘Mass transfer between a bubble and the dense phase in gas fluidized beds of Group A and Group B particles was proposed based on previous experimental results and literature data. The mass transfer coefficient between bubbles and the dense phase was determined by kbe = 0.21 db. A theoretical analysis of the mass transfer coefficient between a bubble and the dense phase using diffusion equations showed that the mass transfer coefficient between a bubble and the dense phase is kbe α εmf√ub/db in both three- and two-dimensional fiuidized beds. An effective diffusion coefficient in gas fluidized beds was introduced and correlated with bubble size as De = 13.3db2.7 for Group A and Group B particles. The mass transfer coefficient kbe can then be expressed as kbe = 0.492εmf√ubdb1.7 for bubbles in a three-dimensional bed and kbe = 0.576εm√ubdb1.7 for bubbles in a two-dimensional bed.
文摘Twelve volunteers with normal hearing (9 males and 3 females) participated in this work The sound transfer functions (STFS) from diffuse sound field to the subject's eardrums were measured and correlated to the temporary threshold shift (TTS) due to fiffuse-exposure.A probe tube with a miniature microphone was used for STF measurements in which successive 1/3 oct bandwidth random noise with central frequency from 0.25 kKz to 8 kHz were used. The subjects were divided into two groups, with the STF maxima at 2 kHz and 4 kHz respectively Pre- and post- exposure sweep Bekesy audiograms were recorded and the temporary thresh old shift calctilated as the difference between the two. Frequency of the maximum TTS was correlated to that of the maximum STF. The average TTS was very small or zero at frequen cies below the band noise exposure , but was noticeable even at the highest measured frequency (8 kHz) for beyond the noise band. Also individual differences in STF were found at frequencies between 2 kHz and 4 kHz
