An initial differential mathematical model of the process of catalytic reactions coupled in a membrane reactor is developed.The "donor" reaction refers to one that produces the key substance that may permeat...An initial differential mathematical model of the process of catalytic reactions coupled in a membrane reactor is developed.The "donor" reaction refers to one that produces the key substance that may permeate the membrane and be consumed by the "acceptor" reaction.According to the maximum principle in mathematics,the analysis indicates that,in order to obtain maximum yield of the "acceptor" reaction,there should exist our optimal profile of the packed-bed catalytic activity on the "acceptor" reaction side of the membrane reactor,which is a one-time open-close function at the optimum position,as followsξ *(z)=0 ? (0<z<z r ) ξ max (z r ≤z≤1)where ξ *(z) is optimal function of catalytic activity, ξ max its maximum value, z the position,and z r the optimum position.The function means physically that catalytic activity equals to zero near the inlet and that,at the optimum position,activity should be kept maximum constant value on the "acceptor" reaction side.Finally the effect of membrane permeability on the optimum catalytic activity is also investigated.It is found that,as the membrane permeability increases,the optimum open-close position of optimal catalytic activity profile function will move closer to the inlet of the membrane reactor.展开更多
With the wide applications of sensor network technology in traffic information acquisition systems,a new measure will be quite necessary to evaluate spatially related properties of traffic information credibility.The ...With the wide applications of sensor network technology in traffic information acquisition systems,a new measure will be quite necessary to evaluate spatially related properties of traffic information credibility.The heterogeneity of spatial distribution of information credibility from sensor networks is analyzed and a new measure,information credibility function(ICF),is proposed to describe this heterogeneity.Three possible functional forms of sensor ICF and their corresponding expressions are presented.Then,two feasible operations of spatial superposition of sensor ICFs are discussed.Finally,a numerical example is introduced to show the calibration method of sensor ICF and obtain the spatially related properties of expressway in Beijing.The results show that the sensor ICF of expressway in Beijing possesses a negative exponent property.The traffic information is more abundant at or near the locations of sensor,while with the distance away from the sensor increasing,the traffic information credibility will be declined by an exponential trend.The new measure provides theoretical bases for the optimal locations of traffic sensor networks and the mechanism research of spatial distribution of traffic information credibility.展开更多
文摘An initial differential mathematical model of the process of catalytic reactions coupled in a membrane reactor is developed.The "donor" reaction refers to one that produces the key substance that may permeate the membrane and be consumed by the "acceptor" reaction.According to the maximum principle in mathematics,the analysis indicates that,in order to obtain maximum yield of the "acceptor" reaction,there should exist our optimal profile of the packed-bed catalytic activity on the "acceptor" reaction side of the membrane reactor,which is a one-time open-close function at the optimum position,as followsξ *(z)=0 ? (0<z<z r ) ξ max (z r ≤z≤1)where ξ *(z) is optimal function of catalytic activity, ξ max its maximum value, z the position,and z r the optimum position.The function means physically that catalytic activity equals to zero near the inlet and that,at the optimum position,activity should be kept maximum constant value on the "acceptor" reaction side.Finally the effect of membrane permeability on the optimum catalytic activity is also investigated.It is found that,as the membrane permeability increases,the optimum open-close position of optimal catalytic activity profile function will move closer to the inlet of the membrane reactor.
基金Project(61104164)supported by the National Natural Science Foundation of ChinaProject(2012AA112401)supported by the National High Technology Research and Development Program of ChinaProject(2012YJS059)supported by the Fundamental Research Funds for the Central Universities of China
文摘With the wide applications of sensor network technology in traffic information acquisition systems,a new measure will be quite necessary to evaluate spatially related properties of traffic information credibility.The heterogeneity of spatial distribution of information credibility from sensor networks is analyzed and a new measure,information credibility function(ICF),is proposed to describe this heterogeneity.Three possible functional forms of sensor ICF and their corresponding expressions are presented.Then,two feasible operations of spatial superposition of sensor ICFs are discussed.Finally,a numerical example is introduced to show the calibration method of sensor ICF and obtain the spatially related properties of expressway in Beijing.The results show that the sensor ICF of expressway in Beijing possesses a negative exponent property.The traffic information is more abundant at or near the locations of sensor,while with the distance away from the sensor increasing,the traffic information credibility will be declined by an exponential trend.The new measure provides theoretical bases for the optimal locations of traffic sensor networks and the mechanism research of spatial distribution of traffic information credibility.
