The treatment of a multicomponent reversible reaction network is extremely complicated because largenumber of rate constants must be precisely determined and because the calculation based on these rateconstants is ted...The treatment of a multicomponent reversible reaction network is extremely complicated because largenumber of rate constants must be precisely determined and because the calculation based on these rateconstants is tedious.In order to reduce the degrees of freedom of the process,the authors propose a methodin which the reactor and the separator are regarded as a whole.Based on this approach,an N-componentreversible reaction system can be dealt with as a two—component system.Consequently,a simple and ac-cessible way of the apparent rate determination is suggested.For fiist-order reactions,an explicit,simplifiedexpression has been derived for both lumped and distributed parameter reaction systems.展开更多
Coke is an important medium for connecting reaction and regeneration of the methanol to propylene process on the ZSM5 catalyst.Coke grows in the meso and macro pores,it gradually worsens the diffusion inside the catal...Coke is an important medium for connecting reaction and regeneration of the methanol to propylene process on the ZSM5 catalyst.Coke grows in the meso and macro pores,it gradually worsens the diffusion inside the catalyst particle.Furthermore,pore plugging is inevitable which causes the deactivation of ZSM5 catalyst.However,current continuum model cannot reflect the changes in pore structure with clear physical concepts.A discrete model that is verified by the carbon deposition experiments is introduced to indicate the behavior of pore plugging effects.Results show that the pore plugging has a significant effect on the performance of the catalyst.The time varying profile of effectiveness factor is obtained,indicating a regular reduction with the increase of the pore plugging effect.Spatial distributions of pore size that would significantly enhance the plugging effect are also identified.展开更多
Hundreds of thousands of experimental data sets of nuclear reactions have been systematically collected,and their number is still growing rapidly.The data and their correlations compose a complex system,which underpin...Hundreds of thousands of experimental data sets of nuclear reactions have been systematically collected,and their number is still growing rapidly.The data and their correlations compose a complex system,which underpins nuclear science and technology.We model the nuclear reaction data as weighted evolving networks for the purpose of data verification and validation.The networks are employed to study the growing cross-section data of a neutron induced threshold reaction(n,2n)and photoneutron reaction.In the networks,the nodes are the historical data,and the weights of the links are the relative deviation between the data points.It is found that the networks exhibit small-world behavior,and their discovery processes are well described by the Heaps law.What makes the networks novel is the mapping relation between the network properties and the salient features of the database:the Heaps exponent corresponds to the exploration efficiency of the specific data set,the distribution of the edge-weights corresponds to the global uncertainty of the data set,and the mean node weight corresponds to the uncertainty of the individual data point.This new perspective to understand the database will be helpful for nuclear data analysis and compilation.展开更多
文摘The treatment of a multicomponent reversible reaction network is extremely complicated because largenumber of rate constants must be precisely determined and because the calculation based on these rateconstants is tedious.In order to reduce the degrees of freedom of the process,the authors propose a methodin which the reactor and the separator are regarded as a whole.Based on this approach,an N-componentreversible reaction system can be dealt with as a two—component system.Consequently,a simple and ac-cessible way of the apparent rate determination is suggested.For fiist-order reactions,an explicit,simplifiedexpression has been derived for both lumped and distributed parameter reaction systems.
基金the Project of National Natural Science Foundation of China(21822809&21978256)the National Science Fund for Distinguished Young(21525627)+1 种基金the Fundamental Research Funds for the Central Universi-ties(2019XZZX004-03)Ningxia Collaborative Innovation Center for Value Upgrading of Coal-based Synthetic Resin(2017DC57)are gratefully acknowledged.Dr.Zuwei Liao express their dedication to Prof.Xingtian Shu on the occasion of his 80th birthday.
文摘Coke is an important medium for connecting reaction and regeneration of the methanol to propylene process on the ZSM5 catalyst.Coke grows in the meso and macro pores,it gradually worsens the diffusion inside the catalyst particle.Furthermore,pore plugging is inevitable which causes the deactivation of ZSM5 catalyst.However,current continuum model cannot reflect the changes in pore structure with clear physical concepts.A discrete model that is verified by the carbon deposition experiments is introduced to indicate the behavior of pore plugging effects.Results show that the pore plugging has a significant effect on the performance of the catalyst.The time varying profile of effectiveness factor is obtained,indicating a regular reduction with the increase of the pore plugging effect.Spatial distributions of pore size that would significantly enhance the plugging effect are also identified.
基金Supported by the National Natural Science Foundation of China(11875328,12075327)。
文摘Hundreds of thousands of experimental data sets of nuclear reactions have been systematically collected,and their number is still growing rapidly.The data and their correlations compose a complex system,which underpins nuclear science and technology.We model the nuclear reaction data as weighted evolving networks for the purpose of data verification and validation.The networks are employed to study the growing cross-section data of a neutron induced threshold reaction(n,2n)and photoneutron reaction.In the networks,the nodes are the historical data,and the weights of the links are the relative deviation between the data points.It is found that the networks exhibit small-world behavior,and their discovery processes are well described by the Heaps law.What makes the networks novel is the mapping relation between the network properties and the salient features of the database:the Heaps exponent corresponds to the exploration efficiency of the specific data set,the distribution of the edge-weights corresponds to the global uncertainty of the data set,and the mean node weight corresponds to the uncertainty of the individual data point.This new perspective to understand the database will be helpful for nuclear data analysis and compilation.
