Deep hydrodesulfurization （HDS） is an important process to produce high quality liquid fuels with ultra-low sul- fur. Process intensification for deep HDS could be implemented by developing new active catalysts and/...Deep hydrodesulfurization （HDS） is an important process to produce high quality liquid fuels with ultra-low sul- fur. Process intensification for deep HDS could be implemented by developing new active catalysts and/or new types of reactors. In this work, the kinetics of dibenzothiophene （DBT） hydrodesulfurization over Ni-P/SBA-15/ cordierite catalyst was investigated at 340-380 ℃ and 3.0-5.0 MPa. The first-order reaction model with respect to both DBT and H2 was used to fit the kinetics data in a batch recycle operation system. It is found that both the activation energy and rate constant over the Ni-P monolithic catalyst under our operating conditions are close to those over conventionally used HDS catalysts. Comparative performance studies of two types of reactors, i.e., trickle bed reactor and monolithic reactor, were performed based on reactor modeling and simulation. The results indicate that the productivity of the monolithic reactor is 3 times higher than that of the trickle bed reactor on a catalyst weight basis since effective utilization of the catalyst is higher in the monolithic reactor, but the volumetric productivity of the monolithic reactor is lower for HDS of DBT. Based on simulation results, a two- reactor-in-series configuration for hydrodesulfurization is proposed, in which a monolithic reactor is followed by a tickled bed reactor so as to attain intensified performance of the system converting fuel oil of different sulfur-containing compounds. It is illustrated that the two reactor scheme outperforms the trickle bed reactor both on reactor volume and catalyst mass bases while the content of sulfur is reduced from 200 μg·g-1 to about 10 μ·g-1.展开更多
More and more out of core problems that involve solving large amounts of data are researched by scientists. The computational grid provides a wide and scalable environment for those large scale computations. A new met...More and more out of core problems that involve solving large amounts of data are researched by scientists. The computational grid provides a wide and scalable environment for those large scale computations. A new method supporting out of core computations on grids is presented in this paper. The framework and the data storage strategy are described, based on which an easy and efficient out of core programming interface is provided for the programmers.展开更多
Long Term Evolution(LTE) and IEEE 802.16 WiMAX are competing access network technologies adopted in 4G wireless networks in recent years.LTE complies with3 GPP standards whereas 802.16 WiMAX is regulated by the Instit...Long Term Evolution(LTE) and IEEE 802.16 WiMAX are competing access network technologies adopted in 4G wireless networks in recent years.LTE complies with3 GPP standards whereas 802.16 WiMAX is regulated by the Institute of Electrical and Electronics Engineers(IEEE).Although WiMAX is already operating commercially in Taiwan,the system is limited to an independent new system that is incompatible with the current 3G system.Hence,the cost of implementing the WiMAX system is relatively high,this being an impediment to its rapid uptake and widespread use.On the other hand,LTE conforms to 3GPP that is supported by telecommunication manufacturers and operators and is,moreover,backward compatible with 3G/UMTS cellular systems.The LTE specifications define how user equipment(UE) connects and communicates with evolved Node B(eNB) base stations.The enhanced version,LTE-Advanced,adds a new entity called the relay node(RN) to widen service coverage,although this change has resulted in a more complex architecture.Mobility management and data forwarding are essential components in wireless mobile networking.This paper focuses on the efficient handover procedure in LTE-Advanced networks,and proposes a Smart Forwarding mechanism to improve the handover performance.Simulation studies show that the proposed Smart Forwarding scheme employs a better operational transmission path that effectively reduces handover latency and signal overhead.展开更多
This paper analyzes the key technology of mobile GIS development, discusses the design method of mobile GIS spatial data management, visualization of spatial data And Spatial data query, tinder Object oriented mode. A...This paper analyzes the key technology of mobile GIS development, discusses the design method of mobile GIS spatial data management, visualization of spatial data And Spatial data query, tinder Object oriented mode. And we develop a set of mobile GIS basic software platform in the Android platform, and tested in the mainstream smart mobile phone with Android operating system, test results show that the software platform can run smoothly. Other users can development a variety of mobile GIS to call the platform through an application service interface.展开更多
A network structure of coalmine integrated automation system based on NetLinx was proposed. The features of three-layer-network structure were discussed in detail. The mechanism of time determination of the network wa...A network structure of coalmine integrated automation system based on NetLinx was proposed. The features of three-layer-network structure were discussed in detail. The mechanism of time determination of the network was analyzed. A design example of the integrated automation system for a real coalmine was presented.展开更多
This paper presents a universal platform "uSensing" to support smartphones to communicate with sensor nodes in Wireless Sensor Networks (WSNs).Since phones have different CPU processers and operating systems...This paper presents a universal platform "uSensing" to support smartphones to communicate with sensor nodes in Wireless Sensor Networks (WSNs).Since phones have different CPU processers and operating systems,it is a challenge to merge these heterogeneities and develop such a universal platform.In this paper,we design both hardware and software to support the "universal" feature of uSensing:1) "uSD" card:an IEEE 802.15.4 physical communication card with SD interface;2) "uSinkWare":a WSNs middleware running on smartphones.Integrated with uSD card and uSinkWare,phones become mobile data sinks to access into WSNs and parse messages from sensor nodes.We demonstrate the proposed uSensing platform in a commercial smartphone to connect with our WSNs testbed,and validate that the smartphone has the same WSNs functions as commercial fixed sink.Additionally,we evaluate the performance of uSensing platform through measuring phone's CPU load and power consumption,and analyze the performance of these metrics theoretically.The results suggest that the phone-based mobile sink has enough capability to serve as a mobile sink of WSNs and can work up to twenty hours due to low power consumption.展开更多
基金Supported by the State Key Development Program for Basic Research of China(2006CB202503)
文摘Deep hydrodesulfurization （HDS） is an important process to produce high quality liquid fuels with ultra-low sul- fur. Process intensification for deep HDS could be implemented by developing new active catalysts and/or new types of reactors. In this work, the kinetics of dibenzothiophene （DBT） hydrodesulfurization over Ni-P/SBA-15/ cordierite catalyst was investigated at 340-380 ℃ and 3.0-5.0 MPa. The first-order reaction model with respect to both DBT and H2 was used to fit the kinetics data in a batch recycle operation system. It is found that both the activation energy and rate constant over the Ni-P monolithic catalyst under our operating conditions are close to those over conventionally used HDS catalysts. Comparative performance studies of two types of reactors, i.e., trickle bed reactor and monolithic reactor, were performed based on reactor modeling and simulation. The results indicate that the productivity of the monolithic reactor is 3 times higher than that of the trickle bed reactor on a catalyst weight basis since effective utilization of the catalyst is higher in the monolithic reactor, but the volumetric productivity of the monolithic reactor is lower for HDS of DBT. Based on simulation results, a two- reactor-in-series configuration for hydrodesulfurization is proposed, in which a monolithic reactor is followed by a tickled bed reactor so as to attain intensified performance of the system converting fuel oil of different sulfur-containing compounds. It is illustrated that the two reactor scheme outperforms the trickle bed reactor both on reactor volume and catalyst mass bases while the content of sulfur is reduced from 200 μg·g-1 to about 10 μ·g-1.
文摘More and more out of core problems that involve solving large amounts of data are researched by scientists. The computational grid provides a wide and scalable environment for those large scale computations. A new method supporting out of core computations on grids is presented in this paper. The framework and the data storage strategy are described, based on which an easy and efficient out of core programming interface is provided for the programmers.
基金supported in part by the National Science Council,Taiwan,"R.O.C.",under grant no.NSC 101-2221-E-164-019 and NSC 101-2221-E-164-020
文摘Long Term Evolution(LTE) and IEEE 802.16 WiMAX are competing access network technologies adopted in 4G wireless networks in recent years.LTE complies with3 GPP standards whereas 802.16 WiMAX is regulated by the Institute of Electrical and Electronics Engineers(IEEE).Although WiMAX is already operating commercially in Taiwan,the system is limited to an independent new system that is incompatible with the current 3G system.Hence,the cost of implementing the WiMAX system is relatively high,this being an impediment to its rapid uptake and widespread use.On the other hand,LTE conforms to 3GPP that is supported by telecommunication manufacturers and operators and is,moreover,backward compatible with 3G/UMTS cellular systems.The LTE specifications define how user equipment(UE) connects and communicates with evolved Node B(eNB) base stations.The enhanced version,LTE-Advanced,adds a new entity called the relay node(RN) to widen service coverage,although this change has resulted in a more complex architecture.Mobility management and data forwarding are essential components in wireless mobile networking.This paper focuses on the efficient handover procedure in LTE-Advanced networks,and proposes a Smart Forwarding mechanism to improve the handover performance.Simulation studies show that the proposed Smart Forwarding scheme employs a better operational transmission path that effectively reduces handover latency and signal overhead.
文摘This paper analyzes the key technology of mobile GIS development, discusses the design method of mobile GIS spatial data management, visualization of spatial data And Spatial data query, tinder Object oriented mode. And we develop a set of mobile GIS basic software platform in the Android platform, and tested in the mainstream smart mobile phone with Android operating system, test results show that the software platform can run smoothly. Other users can development a variety of mobile GIS to call the platform through an application service interface.
文摘A network structure of coalmine integrated automation system based on NetLinx was proposed. The features of three-layer-network structure were discussed in detail. The mechanism of time determination of the network was analyzed. A design example of the integrated automation system for a real coalmine was presented.
基金supported by the National Natural Science Foundation of China under Grant No.60932005China and Europe Government Cooperation Projects of the Ministry of Science and Technology under Grant No.2010DFA11680the Tsinghua Sci-Tech Project under Grant No.2011THZ0
文摘This paper presents a universal platform "uSensing" to support smartphones to communicate with sensor nodes in Wireless Sensor Networks (WSNs).Since phones have different CPU processers and operating systems,it is a challenge to merge these heterogeneities and develop such a universal platform.In this paper,we design both hardware and software to support the "universal" feature of uSensing:1) "uSD" card:an IEEE 802.15.4 physical communication card with SD interface;2) "uSinkWare":a WSNs middleware running on smartphones.Integrated with uSD card and uSinkWare,phones become mobile data sinks to access into WSNs and parse messages from sensor nodes.We demonstrate the proposed uSensing platform in a commercial smartphone to connect with our WSNs testbed,and validate that the smartphone has the same WSNs functions as commercial fixed sink.Additionally,we evaluate the performance of uSensing platform through measuring phone's CPU load and power consumption,and analyze the performance of these metrics theoretically.The results suggest that the phone-based mobile sink has enough capability to serve as a mobile sink of WSNs and can work up to twenty hours due to low power consumption.
