In order to explore the influence of soil resistivity on stray current in power supply system of urban rail transit,we establish an equivalent circuit model of the rail-to-ground structure based on resistance network ...In order to explore the influence of soil resistivity on stray current in power supply system of urban rail transit,we establish an equivalent circuit model of the rail-to-ground structure based on resistance network method first.After measuring the soil resistivity of a real subway system,a simulation model is established in Matlab to obtain the stray currents at different soil resistivities.Then the influence of soil resistivity on stray current is analyzed.Afterwards,to verify the rationality and reliability of the simulation model,we design a test circuit to measure the stray current and rail-to-ground voltage in a real subway system,and a comparison of the experimentally measured results and simulation results is presented.The results show that the stray current is the maximum when the soil resistivity is 211.57Ω·m;when the soil resistivity is 768.47Ω·m,the stray current is the minimum,that is,the smaller the soil resistivity,the greater the stray current.Therefore,the resistivity should be increased as much as possible when ramming the track foundation in urban rail transit system.展开更多
The integrated operation mode of green logistics is a new enterprise's logistics operation and management mode concerning, environment issues based on the traditional integrated mode. Through comparative study on the...The integrated operation mode of green logistics is a new enterprise's logistics operation and management mode concerning, environment issues based on the traditional integrated mode. Through comparative study on the integrated operation mode of logistics based on self.operation, the operation mode of an integrated logistics of enterprises based on TPL the green-supply chain management, and the operation mode of eco-iadustrial park (EIP), a relatively complete objective system structure is put forward for the integrated operation mode of green logistics of enterprises. Furthermore, the correspondent practical mode is also set up to help enterprises, especially for the manufacturing companies, not only improve the environment effectively, but support the technological framework for the enterprise's economic performance and social benefits in order to realize economic, social and environmental benefits are concerned.展开更多
With the growing popularity of data-intensive services on the Internet, the traditional process-centric model for business process meets challenges due to the lack of abilities to describe data semantics and dependenc...With the growing popularity of data-intensive services on the Internet, the traditional process-centric model for business process meets challenges due to the lack of abilities to describe data semantics and dependencies, resulting in the inflexibility of the design and implement for the processes. This paper proposes a novel data-aware business process model which is able to describe both explicit control flow and implicit data flow. Data model with dependencies which are formulated by Linear-time Temporal Logic(LTL) is presented, and their satisfiability is validated by an automaton-based model checking algorithm. Data dependencies are fully considered in modeling phase, which helps to improve the efficiency and reliability of programming during developing phase. Finally, a prototype system based on j BPM for data-aware workflow is designed using such model, and has been deployed to Beijing Kingfore heating management system to validate the flexibility, efficacy and convenience of our approach for massive coding and large-scale system management in reality.展开更多
In the beach well intake system, heat is transferred from soil to fluid when seawater is filtered through the aquifer, providing higher temperature source water to the seawater source heat pump (SWHP) system in winter...In the beach well intake system, heat is transferred from soil to fluid when seawater is filtered through the aquifer, providing higher temperature source water to the seawater source heat pump (SWHP) system in winter. A 3-D coupled seepage and heat transfer model for studying beach well intake system is established by adopting the computer code FLUENT. Numerical results of this model are compared with the experimental results under the same conditions. Based on the experiment-verified coupled model, numerical simulation of the supply water tem-perature is studied over a heating season. Results show that the minimum temperature of supply water is 275.2 K when this intake system continuously provides seawater with flow rate of 35 m3/h to SWHP. Results also indicate that the supply water temperature is higher than seawater, and that the minimum temperature of supply water lags behind seawater, ensuring effective and reliable operation of SWHP.展开更多
The violently penetration of renewables in power supply network leads to situations, by which the offer exceeds the demand. Therefore, it is necessary to include a system for processes' management. SmartGrid is a pla...The violently penetration of renewables in power supply network leads to situations, by which the offer exceeds the demand. Therefore, it is necessary to include a system for processes' management. SmartGrid is a platform over the power supply network. It is represented with its network and services, which also have to be managed. The paper aims to show the second stage of SmartGrid management modeling. It meets heterogeneous requirements of the actors--subscriber without photovoltaics, subscriber with photovoltaics, service provider, network operator, and network elements operator--to service and network management and is oriented to functional areas, covering the life cycle of power supply service: Design, Planning, Installation, Provision, Configuration, Maintenance, Performance, Accounting, Buying Up, Security and Subscriber Control. Functional models for existing networks--telecommunications--are used and they are adapted to power supply. The results are illustrated with three functional areas for service management: Accounting, Buying Up, and Performance. The synthesis of network management functions and network element management functions are similar.展开更多
This paper shows the R&D results of the power supply system in 2006, including the application of speed control assemblies of two 80 MVA MG sets, the modification of the exciting field system, the development of the ...This paper shows the R&D results of the power supply system in 2006, including the application of speed control assemblies of two 80 MVA MG sets, the modification of the exciting field system, the development of the new HV modulators in ECRH system, the update of several poloidal power supplies. It also presents the status of the power suppIy system in HL-2A experimental operation and foresees the power and energy requirements for new power supply system at HL-2M device.展开更多
Generally, supply chain logistics is the unification of logistics, information flow and capital flow, logistics runs through the whole process of the supply chain. Logistics connects the individual enterprise in the s...Generally, supply chain logistics is the unification of logistics, information flow and capital flow, logistics runs through the whole process of the supply chain. Logistics connects the individual enterprise in the supply chain and it is the bond of mutual cooperation between enterprises. In that way, the logistics management becomes an important part of the supply chain management system naturally. However, it is not so long since the theory of supply chain management and logistics management put forward so they are still being refined. Besides, it is lack of green philosophy in the logistics management of the supply chain and effect of logistics on the environment and resource efficiency do not be considered synthetically. Yet, methods to solve the problem that customers return items and waste materials have been excluded from the enterprises and business strategy. With the awareness that people should protect the environment and conserve resources enhanced and governments increase the intensity of environmental regulations constraints, the theory and practice of green logistics management are valued by the foreign supply chain management and logistics management theory community and the business community gradually.展开更多
Through the analysis of the feasibility of using network technology and network technology in supply chain management system, the paper puts forward the design framework of supply chain management system based on the ...Through the analysis of the feasibility of using network technology and network technology in supply chain management system, the paper puts forward the design framework of supply chain management system based on the lntemet of things, describes the key technology of the system. The application of Intemet of things in the supply chain management system, that will realize the effective management of the whole supply chain; enhance the competitiveness of enterprises and the whole supply chain.展开更多
In this paper, we conduct research on the influence of RFID technique on modern retail logistics system under the Internet of things background. The application of Intemet of things make its and related enterprises in...In this paper, we conduct research on the influence of RFID technique on modern retail logistics system under the Internet of things background. The application of Intemet of things make its and related enterprises in the supply chain synchronization integration in the process, timely access to relevant information, understand the real needs of the market, the effective control of each link of the supply chain inventory quantity and effectively reduce the supply chain inventory and capital takes up between cooperative enterprises. Thus, in effectively improve the efficiency of the original system at the same time also save the cost of the supply chain management. With the combination of the RFID technique, we finalize the implementation of the logistics information and automation, automatic identification and inspection of finished goods inspection, greatly reduce the human capital, simplify the acceptance of goods and reduce the cost of handling times and human factors caused losses. In the final part, we conclude the work and propose our prospect.展开更多
In this paper, a small flow rate hydrocarbon turbine pump was used to pressurize the fuel supply system of scramjet engine. Some experiments were carried out to investigate the characteristics of turbine pump driven b...In this paper, a small flow rate hydrocarbon turbine pump was used to pressurize the fuel supply system of scramjet engine. Some experiments were carried out to investigate the characteristics of turbine pump driven by nitrogen or combustion gas under different operating conditions. A experimental database with regard to the curves of the rotational speed, mass flow rate and net head with regard to centrifugal pump were plotted. These curves were represented as functions of the pressure and temperature at turbine inlet/outlet and the throttle diameter at downstream of centrifugal pump. A sensitivity study has been carried out based on design of experiments. The experimental was employed to analyze net head of centrifugal and throttle characteristics. The research results can accumulate foundations for the close loop control system of turbine pump.展开更多
Rapid urbanization causing serious air pollution and ecological risks in the Beijing–Tianjin–Hebei region in North China has attracted worldwide attention. This study estimates the key ecosystem services of land cov...Rapid urbanization causing serious air pollution and ecological risks in the Beijing–Tianjin–Hebei region in North China has attracted worldwide attention. This study estimates the key ecosystem services of land covers in Zhangjiakou and Chengde, and analyzes their main contributions and the effects of ecosystem service flows to Beijing. Results indicated that the total economic value of key ecosystem services in the Zhangjiakou–Chengde region was CNY 189.5 billion in 2013, and that these services were generated mainly from the forestlands, grasslands, and farmlands of Chengde and the eastern region of Zhangjiakou. However, nearly half of land covers provided low ecosystem service values and thus should be enhanced. In addition, approximately 21% of key ecosystem services were delivered from the Zhangjiakou–Chengde region into Beijing, and the flow feasibilities of ecosystem services delivered by water and wind reached 34% and 12%, respectively. Chicheng, Zhuolu, Chongli, Huailai, Xuanhua and Guyuan counties contributed 61% of the ecosystem services flowing into Beijing, and each service showed high regional relationships with Beijing(flow index ≥ 40%). Thus, these services should be prioritized in terms of ecological compensation funds and policies from Beijing.展开更多
The joint operation of inter-basin water transfer-supply(IBWTS)project can be more complex when there is joint water demand in multi-reservoir system and multi-importing reservoirs simultaneously transferring water fr...The joint operation of inter-basin water transfer-supply(IBWTS)project can be more complex when there is joint water demand in multi-reservoir system and multi-importing reservoirs simultaneously transferring water from exporting reservoir.In this study,a joint operating rule is proposed for the purpose of solving such complex operation problem.This rule is composed of a set of sub-rules,including hedging rule curves of virtual aggregation reservoir(i.e.equivalent reservoir)and other individual reservoirs,water-transfer rule curves of each individual reservoir,as well as some of important assisted rules.These assisted rules refer to allocation models for water transfer-supply.In the proposed rule,an equivalent reservoir is established to determine under what condition the water supply should be reduced and specify the total supplied water for joint water demand(i.e.aggregation method).Allocation models are developed to distribute the total transferred water into each importing reservoir and determine the water releases for joint water demand by each member reservoir of the aggregation system(i.e.decomposition method).And these models are integrated with a set of influence factors such as hydrologic characteristics,reservoir storage or vacant storage,regulating ability,water-supply pressure,and so on.The aggregation of multi-reservoirs and the disaggregation of water quantities are taken into a whole consideration to reduce the complexity in reallocation of water target storage or water release.Finally,the proposed rule is applied to the North-line IBWTS Project in Liaoning Province,China.The results indicate that the proposed rule can take full advantage of hydrologic compensation in basins and capacity compensation in reservoirs.Thus it can improve the utilization efficiency of water resources in system.展开更多
基金National Natural Science Foundation of China(Nos.51476073,51266004)Natural Science Foundation of Gansu Province(No.1308RJZA199)。
文摘In order to explore the influence of soil resistivity on stray current in power supply system of urban rail transit,we establish an equivalent circuit model of the rail-to-ground structure based on resistance network method first.After measuring the soil resistivity of a real subway system,a simulation model is established in Matlab to obtain the stray currents at different soil resistivities.Then the influence of soil resistivity on stray current is analyzed.Afterwards,to verify the rationality and reliability of the simulation model,we design a test circuit to measure the stray current and rail-to-ground voltage in a real subway system,and a comparison of the experimentally measured results and simulation results is presented.The results show that the stray current is the maximum when the soil resistivity is 211.57Ω·m;when the soil resistivity is 768.47Ω·m,the stray current is the minimum,that is,the smaller the soil resistivity,the greater the stray current.Therefore,the resistivity should be increased as much as possible when ramming the track foundation in urban rail transit system.
文摘The integrated operation mode of green logistics is a new enterprise's logistics operation and management mode concerning, environment issues based on the traditional integrated mode. Through comparative study on the integrated operation mode of logistics based on self.operation, the operation mode of an integrated logistics of enterprises based on TPL the green-supply chain management, and the operation mode of eco-iadustrial park (EIP), a relatively complete objective system structure is put forward for the integrated operation mode of green logistics of enterprises. Furthermore, the correspondent practical mode is also set up to help enterprises, especially for the manufacturing companies, not only improve the environment effectively, but support the technological framework for the enterprise's economic performance and social benefits in order to realize economic, social and environmental benefits are concerned.
基金supported by the National Natural Science Foundation of China (No. 61502043, No. 61132001)Beijing Natural Science Foundation (No. 4162042)BeiJing Talents Fund (No. 2015000020124G082)
文摘With the growing popularity of data-intensive services on the Internet, the traditional process-centric model for business process meets challenges due to the lack of abilities to describe data semantics and dependencies, resulting in the inflexibility of the design and implement for the processes. This paper proposes a novel data-aware business process model which is able to describe both explicit control flow and implicit data flow. Data model with dependencies which are formulated by Linear-time Temporal Logic(LTL) is presented, and their satisfiability is validated by an automaton-based model checking algorithm. Data dependencies are fully considered in modeling phase, which helps to improve the efficiency and reliability of programming during developing phase. Finally, a prototype system based on j BPM for data-aware workflow is designed using such model, and has been deployed to Beijing Kingfore heating management system to validate the flexibility, efficacy and convenience of our approach for massive coding and large-scale system management in reality.
基金Supported by Tianjin Construction Committee Technology Project (No2007-37)
文摘In the beach well intake system, heat is transferred from soil to fluid when seawater is filtered through the aquifer, providing higher temperature source water to the seawater source heat pump (SWHP) system in winter. A 3-D coupled seepage and heat transfer model for studying beach well intake system is established by adopting the computer code FLUENT. Numerical results of this model are compared with the experimental results under the same conditions. Based on the experiment-verified coupled model, numerical simulation of the supply water tem-perature is studied over a heating season. Results show that the minimum temperature of supply water is 275.2 K when this intake system continuously provides seawater with flow rate of 35 m3/h to SWHP. Results also indicate that the supply water temperature is higher than seawater, and that the minimum temperature of supply water lags behind seawater, ensuring effective and reliable operation of SWHP.
文摘The violently penetration of renewables in power supply network leads to situations, by which the offer exceeds the demand. Therefore, it is necessary to include a system for processes' management. SmartGrid is a platform over the power supply network. It is represented with its network and services, which also have to be managed. The paper aims to show the second stage of SmartGrid management modeling. It meets heterogeneous requirements of the actors--subscriber without photovoltaics, subscriber with photovoltaics, service provider, network operator, and network elements operator--to service and network management and is oriented to functional areas, covering the life cycle of power supply service: Design, Planning, Installation, Provision, Configuration, Maintenance, Performance, Accounting, Buying Up, Security and Subscriber Control. Functional models for existing networks--telecommunications--are used and they are adapted to power supply. The results are illustrated with three functional areas for service management: Accounting, Buying Up, and Performance. The synthesis of network management functions and network element management functions are similar.
文摘This paper shows the R&D results of the power supply system in 2006, including the application of speed control assemblies of two 80 MVA MG sets, the modification of the exciting field system, the development of the new HV modulators in ECRH system, the update of several poloidal power supplies. It also presents the status of the power suppIy system in HL-2A experimental operation and foresees the power and energy requirements for new power supply system at HL-2M device.
文摘Generally, supply chain logistics is the unification of logistics, information flow and capital flow, logistics runs through the whole process of the supply chain. Logistics connects the individual enterprise in the supply chain and it is the bond of mutual cooperation between enterprises. In that way, the logistics management becomes an important part of the supply chain management system naturally. However, it is not so long since the theory of supply chain management and logistics management put forward so they are still being refined. Besides, it is lack of green philosophy in the logistics management of the supply chain and effect of logistics on the environment and resource efficiency do not be considered synthetically. Yet, methods to solve the problem that customers return items and waste materials have been excluded from the enterprises and business strategy. With the awareness that people should protect the environment and conserve resources enhanced and governments increase the intensity of environmental regulations constraints, the theory and practice of green logistics management are valued by the foreign supply chain management and logistics management theory community and the business community gradually.
文摘Through the analysis of the feasibility of using network technology and network technology in supply chain management system, the paper puts forward the design framework of supply chain management system based on the lntemet of things, describes the key technology of the system. The application of Intemet of things in the supply chain management system, that will realize the effective management of the whole supply chain; enhance the competitiveness of enterprises and the whole supply chain.
文摘In this paper, we conduct research on the influence of RFID technique on modern retail logistics system under the Internet of things background. The application of Intemet of things make its and related enterprises in the supply chain synchronization integration in the process, timely access to relevant information, understand the real needs of the market, the effective control of each link of the supply chain inventory quantity and effectively reduce the supply chain inventory and capital takes up between cooperative enterprises. Thus, in effectively improve the efficiency of the original system at the same time also save the cost of the supply chain management. With the combination of the RFID technique, we finalize the implementation of the logistics information and automation, automatic identification and inspection of finished goods inspection, greatly reduce the human capital, simplify the acceptance of goods and reduce the cost of handling times and human factors caused losses. In the final part, we conclude the work and propose our prospect.
基金National Natural Science Foundation of China(No.11272344)
文摘In this paper, a small flow rate hydrocarbon turbine pump was used to pressurize the fuel supply system of scramjet engine. Some experiments were carried out to investigate the characteristics of turbine pump driven by nitrogen or combustion gas under different operating conditions. A experimental database with regard to the curves of the rotational speed, mass flow rate and net head with regard to centrifugal pump were plotted. These curves were represented as functions of the pressure and temperature at turbine inlet/outlet and the throttle diameter at downstream of centrifugal pump. A sensitivity study has been carried out based on design of experiments. The experimental was employed to analyze net head of centrifugal and throttle characteristics. The research results can accumulate foundations for the close loop control system of turbine pump.
基金National Major Research Development Program of China(2016YFC0503403)Special Institute Cultivation Project of Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences(TSYJS05)
文摘Rapid urbanization causing serious air pollution and ecological risks in the Beijing–Tianjin–Hebei region in North China has attracted worldwide attention. This study estimates the key ecosystem services of land covers in Zhangjiakou and Chengde, and analyzes their main contributions and the effects of ecosystem service flows to Beijing. Results indicated that the total economic value of key ecosystem services in the Zhangjiakou–Chengde region was CNY 189.5 billion in 2013, and that these services were generated mainly from the forestlands, grasslands, and farmlands of Chengde and the eastern region of Zhangjiakou. However, nearly half of land covers provided low ecosystem service values and thus should be enhanced. In addition, approximately 21% of key ecosystem services were delivered from the Zhangjiakou–Chengde region into Beijing, and the flow feasibilities of ecosystem services delivered by water and wind reached 34% and 12%, respectively. Chicheng, Zhuolu, Chongli, Huailai, Xuanhua and Guyuan counties contributed 61% of the ecosystem services flowing into Beijing, and each service showed high regional relationships with Beijing(flow index ≥ 40%). Thus, these services should be prioritized in terms of ecological compensation funds and policies from Beijing.
基金supported by the Major International(Regional)Cooperation Project(Grant No.51320105010)the National Natural Science Foundation of China(Grant Nos.51379027,51109025)the Fundamental Research Fund for the Central Universities(Grant No.DUT13JS06)
文摘The joint operation of inter-basin water transfer-supply(IBWTS)project can be more complex when there is joint water demand in multi-reservoir system and multi-importing reservoirs simultaneously transferring water from exporting reservoir.In this study,a joint operating rule is proposed for the purpose of solving such complex operation problem.This rule is composed of a set of sub-rules,including hedging rule curves of virtual aggregation reservoir(i.e.equivalent reservoir)and other individual reservoirs,water-transfer rule curves of each individual reservoir,as well as some of important assisted rules.These assisted rules refer to allocation models for water transfer-supply.In the proposed rule,an equivalent reservoir is established to determine under what condition the water supply should be reduced and specify the total supplied water for joint water demand(i.e.aggregation method).Allocation models are developed to distribute the total transferred water into each importing reservoir and determine the water releases for joint water demand by each member reservoir of the aggregation system(i.e.decomposition method).And these models are integrated with a set of influence factors such as hydrologic characteristics,reservoir storage or vacant storage,regulating ability,water-supply pressure,and so on.The aggregation of multi-reservoirs and the disaggregation of water quantities are taken into a whole consideration to reduce the complexity in reallocation of water target storage or water release.Finally,the proposed rule is applied to the North-line IBWTS Project in Liaoning Province,China.The results indicate that the proposed rule can take full advantage of hydrologic compensation in basins and capacity compensation in reservoirs.Thus it can improve the utilization efficiency of water resources in system.