To cultivate new professional farmers is a key way for rural labor development, resolving existing problems such as how to farming. It is notable that government and market take advantages in training of new professio...To cultivate new professional farmers is a key way for rural labor development, resolving existing problems such as how to farming. It is notable that government and market take advantages in training of new professional farmers. Therefore, it is necessary to guarantee government and market playing the roles. The research explored market-oriented farmer training model and the characteristics and investigated training routes for new professional farmers.展开更多
Given the prominence and magnitude of airport incentive schemes,it is surprising that literature hitherto remains silent as to their effectiveness.In this paper,the relationship between airport incentive schemes and t...Given the prominence and magnitude of airport incentive schemes,it is surprising that literature hitherto remains silent as to their effectiveness.In this paper,the relationship between airport incentive schemes and the route development behavior of airlines is analyzed.Because of rare and often controversial findings in the extant literature regarding relevant influencing variables for attracting airlines at an airport,expert interviews are used as a complement to formulate testable hypotheses in this regard.A fixed effects regression model is used to test the hypotheses with a dataset that covers all seat capacity offered at the 22 largest German commercial airports in the week 46 from 2004 to 2011.It is found that incentives from primary choice,as well as secondary choice airports,have a significant influence on Low Cost Carriers.Furthermore,Low Cost Carriers,in general,do not leave any of both types of airports when the incentives cease.In the case of Network Carriers,no case is found where one joins a primary choice airport and receives an incentive.Insufficient data between Network Carriers and secondary choice airports in the time when incentives have ceased means that no statement can be given.展开更多
The CAS Institute of Modern Physics is a center of pure basic research concerning nuclear physics, accelerator physics and related technology. In recent years, it succeeded in the construction of China’s first produc...The CAS Institute of Modern Physics is a center of pure basic research concerning nuclear physics, accelerator physics and related technology. In recent years, it succeeded in the construction of China’s first production line for manufacturing radiation-crosslinked (RC) wire and cable with the aid of international cooperation,achieving rewarding benefits from it.展开更多
Electric vehicles(EVs)have received significant attention because of the potential energy savings and emission reductions they enable.However,current studies and demonstrations have focused mainly on specific technolo...Electric vehicles(EVs)have received significant attention because of the potential energy savings and emission reductions they enable.However,current studies and demonstrations have focused mainly on specific technologies and equipment types,which cannot in themselves solve the predicaments facing EVs.This study points out that EVs will form a large,complex system that needs to be optimized over different aspects to compete with traditional vehicles.Therefore,wholesystem thinking is needed to support the development control of EVs,with a broader scope than operational control,and the core issue is the interaction between EVs and power grid,including their coordinated development and operational management.For development control of EVs,a target system and a step-wise optimization method are presented,as well as the basic principles for designing the target system.There are two key barriers in EVs’development:the research and mass production of highperformance power batteries,and the formulation of a favorable mechanism to capture benefits and encourage development.To address the problems of EV development,a promotion method that combines franchising with moderate competition is proposed.The concepts and methods developed in this study can facilitate the research and development of EVs.展开更多
Because of the harsh reaction conditions and relatively low ammonia(NH_(3))yield of the Haber-Bosch process in the synthetic NH_(3) industry,it is highly desirable to develop an alternative route for efficient dinitro...Because of the harsh reaction conditions and relatively low ammonia(NH_(3))yield of the Haber-Bosch process in the synthetic NH_(3) industry,it is highly desirable to develop an alternative route for efficient dinitrogen(N_(2))fixation under milder conditions.Dual-atom catalysts(DACs),in which metal dimers are anchored on an appropriate substrate,not only possess the advantage of single-atom catalysts,but also boast higher metal atom loading and more flexible active sites.In the present paper,a tantalum(Ta)atom was anchored onto a mono-Ta-substituted Keggin-type polyoxometalate(POM)support to form a homo-nuclear DAC for the nitrogen reduction reaction(NRR).According to our density functional theory(DFT)calculations,we found that the metal-support interaction of the DAC studied here was mainly determined by the bonding interaction,rather than the electrostatic force.Moreover,the DAC studied here possesses matching energy levels of frontier molecular orbitals(FMOs)for the activation of an inert N_(2) molecule.The electronic structural and geometric analyses show that the suitable Ta-Ta distance and unique molecular orbital topology are responsible for the effective electron transfer from dxy orbitals of two Ta centers to the phase matchingπ^(*)_(2px) unoccupied orbital of the N_(2) molecule.Free energy calculations show that the elemental steps for the reduction of N_(2) to NH_(3) on the DAC studied here are all thermodynamic allowed.The unique tilted arrangement of the adsorbed N_(2) molecule significantly decreases the reaction free energy for the hydrogenation of the adsorbed N_(2) molecule to the N_(2)H intermediate,which is always found to be the rate-determining step of the NRR in most catalytic systems.We hope that our findings would provide new insights into the catalytic mechanism of DACs for the NRR at the atomic level.展开更多
基金Supported by Chongqing Education Science Planning Program(2013-ZJ-060)Humanities and Social Science Research Planning Program of Ministry of Education(13YJA630042)+1 种基金Humanities and Social Science Research Program of Chongqing Education Committee(14SKN03)S&T Innovation Team Construction and Planning Foundation of Yangtze Normal University(2014XJTD03)~~
文摘To cultivate new professional farmers is a key way for rural labor development, resolving existing problems such as how to farming. It is notable that government and market take advantages in training of new professional farmers. Therefore, it is necessary to guarantee government and market playing the roles. The research explored market-oriented farmer training model and the characteristics and investigated training routes for new professional farmers.
文摘Given the prominence and magnitude of airport incentive schemes,it is surprising that literature hitherto remains silent as to their effectiveness.In this paper,the relationship between airport incentive schemes and the route development behavior of airlines is analyzed.Because of rare and often controversial findings in the extant literature regarding relevant influencing variables for attracting airlines at an airport,expert interviews are used as a complement to formulate testable hypotheses in this regard.A fixed effects regression model is used to test the hypotheses with a dataset that covers all seat capacity offered at the 22 largest German commercial airports in the week 46 from 2004 to 2011.It is found that incentives from primary choice,as well as secondary choice airports,have a significant influence on Low Cost Carriers.Furthermore,Low Cost Carriers,in general,do not leave any of both types of airports when the incentives cease.In the case of Network Carriers,no case is found where one joins a primary choice airport and receives an incentive.Insufficient data between Network Carriers and secondary choice airports in the time when incentives have ceased means that no statement can be given.
文摘The CAS Institute of Modern Physics is a center of pure basic research concerning nuclear physics, accelerator physics and related technology. In recent years, it succeeded in the construction of China’s first production line for manufacturing radiation-crosslinked (RC) wire and cable with the aid of international cooperation,achieving rewarding benefits from it.
基金This work was partially supported National High Technology R&D Program of China(863 Program)(No.2012AA050804).
文摘Electric vehicles(EVs)have received significant attention because of the potential energy savings and emission reductions they enable.However,current studies and demonstrations have focused mainly on specific technologies and equipment types,which cannot in themselves solve the predicaments facing EVs.This study points out that EVs will form a large,complex system that needs to be optimized over different aspects to compete with traditional vehicles.Therefore,wholesystem thinking is needed to support the development control of EVs,with a broader scope than operational control,and the core issue is the interaction between EVs and power grid,including their coordinated development and operational management.For development control of EVs,a target system and a step-wise optimization method are presented,as well as the basic principles for designing the target system.There are two key barriers in EVs’development:the research and mass production of highperformance power batteries,and the formulation of a favorable mechanism to capture benefits and encourage development.To address the problems of EV development,a promotion method that combines franchising with moderate competition is proposed.The concepts and methods developed in this study can facilitate the research and development of EVs.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(32130073 and 21373043).
文摘Because of the harsh reaction conditions and relatively low ammonia(NH_(3))yield of the Haber-Bosch process in the synthetic NH_(3) industry,it is highly desirable to develop an alternative route for efficient dinitrogen(N_(2))fixation under milder conditions.Dual-atom catalysts(DACs),in which metal dimers are anchored on an appropriate substrate,not only possess the advantage of single-atom catalysts,but also boast higher metal atom loading and more flexible active sites.In the present paper,a tantalum(Ta)atom was anchored onto a mono-Ta-substituted Keggin-type polyoxometalate(POM)support to form a homo-nuclear DAC for the nitrogen reduction reaction(NRR).According to our density functional theory(DFT)calculations,we found that the metal-support interaction of the DAC studied here was mainly determined by the bonding interaction,rather than the electrostatic force.Moreover,the DAC studied here possesses matching energy levels of frontier molecular orbitals(FMOs)for the activation of an inert N_(2) molecule.The electronic structural and geometric analyses show that the suitable Ta-Ta distance and unique molecular orbital topology are responsible for the effective electron transfer from dxy orbitals of two Ta centers to the phase matchingπ^(*)_(2px) unoccupied orbital of the N_(2) molecule.Free energy calculations show that the elemental steps for the reduction of N_(2) to NH_(3) on the DAC studied here are all thermodynamic allowed.The unique tilted arrangement of the adsorbed N_(2) molecule significantly decreases the reaction free energy for the hydrogenation of the adsorbed N_(2) molecule to the N_(2)H intermediate,which is always found to be the rate-determining step of the NRR in most catalytic systems.We hope that our findings would provide new insights into the catalytic mechanism of DACs for the NRR at the atomic level.
