Identifying the driving forces that cause changes in forest ecosystem services related to water conservation is essential for the design of interventions that could enhance positive impacts as well as minimizing negat...Identifying the driving forces that cause changes in forest ecosystem services related to water conservation is essential for the design of interventions that could enhance positive impacts as well as minimizing negative impacts. In this study, we propose an assessment concept framework model for indirect-direct-ecosystem service (IN-DI-ESS) driving forces within this context and method for index construction that considers the selection of a robust and parsimonious variable set. Factor analysis was integrated into two-stage data envelopment analysis (TS-DEA) to determine the driving forces and their effects on water conservation services in forest ecosystems at the provincial scale in China. The results showed the following. 1) Ten indicators with factor scores more than 0.8 were selected as the minimum data set. Four indicators comprising population density, per capita gross domestic product, irrigation efficiency, and per capita food consumption were the indirect driving factors, and six indicators comprising precipitation, farmland into forestry or pasture, forest cover, habitat area, water footprint, and wood extraction were the direct driving forces. 2) Spearman's rank correlation test was performed to compare the overall effectiveness in two periods: stage 1 and stage 2. The calculated coefficients were 0.245, 0.136, and 0.579, respectively, whereas the tabulated value was 0.562. This indicates that the driving forces obviously differed in terms of their contribution to the overall effectiveness and they caused changes in water conservation services in different stages. In terms of the variations in different driving force effects in the years 2000 and 2010, the overall, stage 1, and stage 2 variances were 0.020, 0.065, and 0.079 in 2000, respectively, and 0.018, 0.063, and 0.071 in 2010. This also indicates that heterogeneous driving force effects were obvious in the process during the same period. Identifying the driving forces that affect service changes and evaluating their efficiency have significant policy implications for the management of forest ecosystem services. Advanced effectiveness measures for weak regions could be improved in an appropriate manner. In this study, we showed that factor analysis coupled with TS-DEA based on the IN-D1-ESS framework can increase the parsimony of driving force indicators, as well as interpreting the interactions among indirect and direct driving forces with forest ecosystem water conservation services, and reducing the uncertainty related to the internal consistency during data selection.展开更多
Given its relevance to the exploitation of ultra-low permeability reservoirs,which account for a substantial proportion of the world’s exploited and still unexploited reserves,in the present study the development of ...Given its relevance to the exploitation of ultra-low permeability reservoirs,which account for a substantial proportion of the world’s exploited and still unexploited reserves,in the present study the development of an adequate water injection system is considered.Due to the poor properties and weak seepage capacity of these reservoirs,the water injection pressure typically increases continuously during water flooding.In this research,the impact on such a process of factors as permeability,row spacing,and pressure gradient is evaluated experimentally using a high-pressure large-scale outcrop model.On this basis,a comprehensive evaluation coefficient is introduced able to account for the effective driving pressure.展开更多
From the perspective of man–land relationship, Yancheng City(ruins of Yancheng in the Spring and Autumn Period) as a typical theme tourist destination is selected to construct the structural model of driving effect o...From the perspective of man–land relationship, Yancheng City(ruins of Yancheng in the Spring and Autumn Period) as a typical theme tourist destination is selected to construct the structural model of driving effect of tourist destination attributes on tourists' place attachment, and carry out the empirical research. The results show that attributes of Yancheng City contain 4 dimensions, and tourists' perception of the attributes declines in the sequence "recreational and entertainment attribute→ attribute of culture of the Spring and Autumn Period→ attribute of landscapes and ruins→ attribute of humanistic concern"; the four-dimension attributes vary greatly in driving tourists' place attachment, recreational and entertainment attribute and attribute of culture of the Spring and Autumn Period have obvious positive driving effect, attribute of landscapes and ruins and attribute of humanistic concern have poorer driving effect; generally speaking, driving effect of tourist destination attributes on tourists' place attachment is demonstrated as "highlighted value functions of tourist destination attributes→‘predominant area' of tourists' perceptual experience→ obvious driving effect on tourists' place attachment" and "hysteretic value functions of tourist destination attributes→‘vulnerable area' of tourists' perceptual experience→ weakened driving effect on tourists' place attachment"; driving effect of the overall attributes of tourist destination on tourists' place attachment is to be further improved and optimized.展开更多
SDA (Structural Decomposition Analysis) model was applied to analyze the driving factors of embodied carbon and SO_(2) emissions transferred in Shanxi during 2007-2012 based on the input-output model from the perspect...SDA (Structural Decomposition Analysis) model was applied to analyze the driving factors of embodied carbon and SO_(2) emissions transferred in Shanxi during 2007-2012 based on the input-output model from the perspectives of region and industry.The results showed that the change of embodied carbon emissions and embodied SO_(2) emissions of Shanxi and other regions were hindered by the carbon (sulfur) emissions strength effect,but promoted by the intermediate (final) demand scale effect,the intermediate (final) structure effect and the input-output structure effect.The carbon emissions strength effect had a significant contribution to reducing the embodied carbon emissions transferred from industries in Shanxi to other regions.The intermediate (final) demand scale effect was the driving factor to increase the embodied carbon emissions transferred from industries in Shanxi to other regions.The sulfur emissions strength effect was the only factor that reduced the embodied SO_(2) emissions transferred from Shanxi to other industries.The change of embodied carbon emissions from industries in other regions to Shanxi was hindered by the carbon emissions strength effect,but the input-output structure effect and final demand scale effect both increased the embodied carbon emissions from industries in other regions to Shanxi.The change of the embodied SO_(2) emissions transferred from industries in other regions to Shanxi was inhibited by the sulfur emissions strength effect,but the input-output structure effect,the intermediate demand structure effect and the final demand scale effect were both the driving force effect of increasing the embodied SO_(2) emissions transferred from industries in other regions to Shanxi.The corresponding suggestions and measures were put forward.展开更多
The effect of the wave accessibility condition on the lower hybrid cm'rent drive in the experimental advanced superconductor Tokamak (EAST) plasma with H-mode operation is studied. Based on a simplified model, a mo...The effect of the wave accessibility condition on the lower hybrid cm'rent drive in the experimental advanced superconductor Tokamak (EAST) plasma with H-mode operation is studied. Based on a simplified model, a mode conversion layer of the lower hybrid wave between the fast wave branch and the slow wave branch is proved to exist in the plasma periphery for typical EAST H-mode parameters. Under the framework of the lower hybrid wave simulation code (LSC), the wave ray trajectory and the associated current drive are calculated numerically. The results show that the wave accessibility condition plays an important role on the lower hybrid current drive in EAST plasma. For wave rays with parallel refractive index n||= 2.1 or n|| = 2.5 launched from the outside midplane, the wave rays may penetrate the core plasma due to the toroida] geometry effect, while numerous reflections of the wave ray trajectories in the plasma periphery occur. However, low current drive efficiency is obtained. Meanwhile, the wave accessibility condition is improved if a higher confined magnetic field is applied. The simulation results show that for plasma parameters under present EAST H-mode operation, a significant lower hybrid wave current drive could be obtained for the wave spectrum with peak value n|| = 2.1 if a toroidal magnetic field BT =2.5 T is applied.展开更多
Based on the Keynesian IS curve and MS-TVTP model,this paper studies the phase operating characteristics and driving mechanism of Chinese business growth cycle fluctuation by specifying output gap series through coinc...Based on the Keynesian IS curve and MS-TVTP model,this paper studies the phase operating characteristics and driving mechanism of Chinese business growth cycle fluctuation by specifying output gap series through coincident composite index and estimating expectation variable through state space model.The results are that the influences of output gap expectation on business growth cycle are positive and the effects of real interest rate are negative.Both of them exert asymmetric features in different regimes.The estimation results of smoothed probability and transition probability show that the financial and investment composite indexes are the significant driving factors of business growth cycle switch among different regimes.Compared to promoting economic growth,the monetary policy plays a more effective role in decelerating the growth speed.Although the speed of investment’s influence during the economic downturn phase is rapid,the lag of its effects is lengthened due to the investment cycle and capital formation.Releasing reform dividend through stabilizing expectation and reducing the fluctuation of business cycle by employing the macro prudent government are important ways to maintain the steady growth of Chinese economy.展开更多
基金Under the auspices of Science and Technology Service Network Initiative Project of the Chinese Academy of Sciences(No.KFJ-EW-STS-002)
文摘Identifying the driving forces that cause changes in forest ecosystem services related to water conservation is essential for the design of interventions that could enhance positive impacts as well as minimizing negative impacts. In this study, we propose an assessment concept framework model for indirect-direct-ecosystem service (IN-DI-ESS) driving forces within this context and method for index construction that considers the selection of a robust and parsimonious variable set. Factor analysis was integrated into two-stage data envelopment analysis (TS-DEA) to determine the driving forces and their effects on water conservation services in forest ecosystems at the provincial scale in China. The results showed the following. 1) Ten indicators with factor scores more than 0.8 were selected as the minimum data set. Four indicators comprising population density, per capita gross domestic product, irrigation efficiency, and per capita food consumption were the indirect driving factors, and six indicators comprising precipitation, farmland into forestry or pasture, forest cover, habitat area, water footprint, and wood extraction were the direct driving forces. 2) Spearman's rank correlation test was performed to compare the overall effectiveness in two periods: stage 1 and stage 2. The calculated coefficients were 0.245, 0.136, and 0.579, respectively, whereas the tabulated value was 0.562. This indicates that the driving forces obviously differed in terms of their contribution to the overall effectiveness and they caused changes in water conservation services in different stages. In terms of the variations in different driving force effects in the years 2000 and 2010, the overall, stage 1, and stage 2 variances were 0.020, 0.065, and 0.079 in 2000, respectively, and 0.018, 0.063, and 0.071 in 2010. This also indicates that heterogeneous driving force effects were obvious in the process during the same period. Identifying the driving forces that affect service changes and evaluating their efficiency have significant policy implications for the management of forest ecosystem services. Advanced effectiveness measures for weak regions could be improved in an appropriate manner. In this study, we showed that factor analysis coupled with TS-DEA based on the IN-D1-ESS framework can increase the parsimony of driving force indicators, as well as interpreting the interactions among indirect and direct driving forces with forest ecosystem water conservation services, and reducing the uncertainty related to the internal consistency during data selection.
基金The authors gratefully acknowledge the financial support from the National Science and Technology Major Project of China(Grant Nos.2017ZX05013-001 and 2017ZX05069-003).
文摘Given its relevance to the exploitation of ultra-low permeability reservoirs,which account for a substantial proportion of the world’s exploited and still unexploited reserves,in the present study the development of an adequate water injection system is considered.Due to the poor properties and weak seepage capacity of these reservoirs,the water injection pressure typically increases continuously during water flooding.In this research,the impact on such a process of factors as permeability,row spacing,and pressure gradient is evaluated experimentally using a high-pressure large-scale outcrop model.On this basis,a comprehensive evaluation coefficient is introduced able to account for the effective driving pressure.
基金Sponsored by National Natural Science Foundation(41401152)Humanities and Social Sciences Youth Program of the Ministry of Education(14YJCZH228)2013 Key Humanities and Social Sciences Program of Nanjing Institute of Industry Technology(YK13-05-03)
文摘From the perspective of man–land relationship, Yancheng City(ruins of Yancheng in the Spring and Autumn Period) as a typical theme tourist destination is selected to construct the structural model of driving effect of tourist destination attributes on tourists' place attachment, and carry out the empirical research. The results show that attributes of Yancheng City contain 4 dimensions, and tourists' perception of the attributes declines in the sequence "recreational and entertainment attribute→ attribute of culture of the Spring and Autumn Period→ attribute of landscapes and ruins→ attribute of humanistic concern"; the four-dimension attributes vary greatly in driving tourists' place attachment, recreational and entertainment attribute and attribute of culture of the Spring and Autumn Period have obvious positive driving effect, attribute of landscapes and ruins and attribute of humanistic concern have poorer driving effect; generally speaking, driving effect of tourist destination attributes on tourists' place attachment is demonstrated as "highlighted value functions of tourist destination attributes→‘predominant area' of tourists' perceptual experience→ obvious driving effect on tourists' place attachment" and "hysteretic value functions of tourist destination attributes→‘vulnerable area' of tourists' perceptual experience→ weakened driving effect on tourists' place attachment"; driving effect of the overall attributes of tourist destination on tourists' place attachment is to be further improved and optimized.
文摘SDA (Structural Decomposition Analysis) model was applied to analyze the driving factors of embodied carbon and SO_(2) emissions transferred in Shanxi during 2007-2012 based on the input-output model from the perspectives of region and industry.The results showed that the change of embodied carbon emissions and embodied SO_(2) emissions of Shanxi and other regions were hindered by the carbon (sulfur) emissions strength effect,but promoted by the intermediate (final) demand scale effect,the intermediate (final) structure effect and the input-output structure effect.The carbon emissions strength effect had a significant contribution to reducing the embodied carbon emissions transferred from industries in Shanxi to other regions.The intermediate (final) demand scale effect was the driving factor to increase the embodied carbon emissions transferred from industries in Shanxi to other regions.The sulfur emissions strength effect was the only factor that reduced the embodied SO_(2) emissions transferred from Shanxi to other industries.The change of embodied carbon emissions from industries in other regions to Shanxi was hindered by the carbon emissions strength effect,but the input-output structure effect and final demand scale effect both increased the embodied carbon emissions from industries in other regions to Shanxi.The change of the embodied SO_(2) emissions transferred from industries in other regions to Shanxi was inhibited by the sulfur emissions strength effect,but the input-output structure effect,the intermediate demand structure effect and the final demand scale effect were both the driving force effect of increasing the embodied SO_(2) emissions transferred from industries in other regions to Shanxi.The corresponding suggestions and measures were put forward.
基金Supported by the National Natural Science Foundation of China under Grant No 11347002the National Magnetic Confinement Fusion Science Program of China under Grant No 2013GB111000+2 种基金the Outstanding Youth Fund of Hunan Province Education Department of China under Grant No 12B107the JSPS-NRF-NSFC A3 Foresight Program in the field of Plasma Physics under Grant No 11261140328the National Research Foundation 2012K2A2A6000443
文摘The effect of the wave accessibility condition on the lower hybrid cm'rent drive in the experimental advanced superconductor Tokamak (EAST) plasma with H-mode operation is studied. Based on a simplified model, a mode conversion layer of the lower hybrid wave between the fast wave branch and the slow wave branch is proved to exist in the plasma periphery for typical EAST H-mode parameters. Under the framework of the lower hybrid wave simulation code (LSC), the wave ray trajectory and the associated current drive are calculated numerically. The results show that the wave accessibility condition plays an important role on the lower hybrid current drive in EAST plasma. For wave rays with parallel refractive index n||= 2.1 or n|| = 2.5 launched from the outside midplane, the wave rays may penetrate the core plasma due to the toroida] geometry effect, while numerous reflections of the wave ray trajectories in the plasma periphery occur. However, low current drive efficiency is obtained. Meanwhile, the wave accessibility condition is improved if a higher confined magnetic field is applied. The simulation results show that for plasma parameters under present EAST H-mode operation, a significant lower hybrid wave current drive could be obtained for the wave spectrum with peak value n|| = 2.1 if a toroidal magnetic field BT =2.5 T is applied.
基金the stage research results of a national nature science fund project:“research on the inner driving mechanism of China high tech industry R&D investment on technology innovation:structure change,two sides and policy effect(71303035)”Talents support plan in Liaoning Province higher education“research on effect mechanism of high technology industries in R&D investment on technological progress”.
文摘Based on the Keynesian IS curve and MS-TVTP model,this paper studies the phase operating characteristics and driving mechanism of Chinese business growth cycle fluctuation by specifying output gap series through coincident composite index and estimating expectation variable through state space model.The results are that the influences of output gap expectation on business growth cycle are positive and the effects of real interest rate are negative.Both of them exert asymmetric features in different regimes.The estimation results of smoothed probability and transition probability show that the financial and investment composite indexes are the significant driving factors of business growth cycle switch among different regimes.Compared to promoting economic growth,the monetary policy plays a more effective role in decelerating the growth speed.Although the speed of investment’s influence during the economic downturn phase is rapid,the lag of its effects is lengthened due to the investment cycle and capital formation.Releasing reform dividend through stabilizing expectation and reducing the fluctuation of business cycle by employing the macro prudent government are important ways to maintain the steady growth of Chinese economy.