The development of any analytical method should have to experience at least four stages: its initial status, growth, mature and declining. However, although the regional input-output analysis has been widely applied f...The development of any analytical method should have to experience at least four stages: its initial status, growth, mature and declining. However, although the regional input-output analysis has been widely applied for more than forty years, it is still one of the most important approach in regional economic analysis and forecast at present in the world. This is due to the never ended modifications and its great potentials. In this paper, we review the historical development of the regional input-output analysis.展开更多
Purpose:The study evaluates the relative roles of Domestic-Funded Enterprises(DFEs)and Foreign-Funded Enterprises(FFEs)across Chinese provinces.It further examines how industrial structures differ by ownership at both...Purpose:The study evaluates the relative roles of Domestic-Funded Enterprises(DFEs)and Foreign-Funded Enterprises(FFEs)across Chinese provinces.It further examines how industrial structures differ by ownership at both regional and national scales.Drawing on these findings,the analysis traces the geographic shift of FFEs and offers evidence-based guidance for shaping foreign investment policy.Design/methodology/approach:This study uses Inter-Country Input-Output(ICIO)and Inter-Region Input-Output(IRIO)tables to build two extended datasets:Ownership-Extended Inter-Country Input-Output(OE-ICIO)and Ownership-Extended Multi-Region Input-Output(OE-IRIO)tables.These are then combined to construct the Regionally-Ownership Dually-Extended Multi-Regional Input-Output(RODE-MRIO)table and Global Domestic and Foreign Enterprises Network(GDFEN)model to explore the industrial relocation trends of FFEs in China.Findings:The results indicate that:(1)From 2010 to 2019,FFEs in China showed an overall decline in influence,profitability,and network robustness.(2)Eastern and developed regions saw a clear retreat of FFEs,with a shift toward domestic control.Central regions and more developed regions played a transitional role.Moreover,western and less developed regions remained stable but still relied on low-end and resource-based activities.(3)FFEs’influence has been gradually shifting towards less-developed central and western provinces due to rising labor costs and stricter environmental regulations.Research limitations:First,only general policy recommendations are proposed,without exploring the design of specific policy instruments.Second,the significant impact of recent trade measures on the behavior of FFEs has not been considered.Third,further research is needed to deepen the analysis by comparing regional ownership dynamics in China with those in other major economies.Practical implications:This research provides valuable insights for policymakers aiming to enhance regional economic development and improve China’s position within Global Value Chains(GVCs).Originality/value:The originality of this paper lies in its development of a new model that combines geographic,sectoral,and ownership dimensions.This model allows for a clearer analysis of the roles of foreign and DFEs in China’s regional economy.It offers insights into industrial transfer trends within global value chains and provides a framework for analyzing and forecasting future shifts.展开更多
The estimation of regional input-output tables is well discussed in the literature and a large variety of methods exist. In this paper we will use the concept of fundamental economic structure （FES） to estimate the ...The estimation of regional input-output tables is well discussed in the literature and a large variety of methods exist. In this paper we will use the concept of fundamental economic structure （FES） to estimate the matrix of intermediate deliveries for some ＂missing＂ region（s）. Furthermore, the estimates will be compared with the estimates obtained from ＂traditional＂ estimating techniques, including regionalization on the basis of the national table, and borrowing coefficients from similar regions. The results show FES is very helpful for compiling regional tables of China.展开更多
Given the statistical gaps in material flow among provinces in China, a method was introduced to estimate regional physical imports and exports （RPIE）, which includes international and interregional imports/ exports...Given the statistical gaps in material flow among provinces in China, a method was introduced to estimate regional physical imports and exports （RPIE）, which includes international and interregional imports/ exports. This method uses provincial monetary input- output tables （MIOT） and international trade statistics. A coefficient matrix representing correlations between monetary value and physical mass for years 2000-2009 was obtained based on a detailed commodity classification and 22 material production sectors in MIOT. With the coefficient matrix as reference, RPIE was measured. Pilot calculation of both regional physical trade balance and domestic material consumption, as well as a brief analysis of these methods, were conducted using 2002 data.展开更多
The transport behavior of pollutants under dynamic groundwater conditions has attracted significant attention recently.However,there is limited research on the simultaneous effects of groundwater table fluctuations on...The transport behavior of pollutants under dynamic groundwater conditions has attracted significant attention recently.However,there is limited research on the simultaneous effects of groundwater table fluctuations on the transport of co-existing pollutants,especially combined dense and light non-aqueous phase liquids(DNAPLs and LNAPLs).In this study,column experiments investigated toluene and dichloromethane transport in a controlled water table system with varying fluctuation conditions.Results showed that both dichloromethane and toluene accumulated near the groundwater table under static water table conditions,but the concentration of dichloromethane declined more rapidly than toluene due to differences in their physicochemical properties,such as solubility,density,and hydrophobicity.Groundwater fluctuations facilitated pollutants transportation towards deeper layers,potentially resulting in unforeseen increases in pollutant volatilization and downward fluxes.The interactions between dichloromethane and toluene,including competitive adsorption,enhanced dissolution,and altered kinematic viscosities,resulted in the reduced transport potential of dichloromethane while enhancing that of toluene.Furthermore,compared to dichloromethane,the initial upward fluctuation of the water table had a more pronounced impact on toluene due to its lower solubility and volatility.The downward transport risk index assessment indicated that among various factors considered,groundwater fluctuation amplitude exerted the most significant influence on pollutant migration risk.These new findings will provide important insights into understanding and assessment of the potential transport risk associated with combined LNAPLs and DNAPLs in the natural environment.展开更多
Severe failures of nonstructural components have occurred during previous earthquakes.Claddings are one of the most widely used nonstructural component and are installed in many modern buildings;therefore,an evaluatio...Severe failures of nonstructural components have occurred during previous earthquakes.Claddings are one of the most widely used nonstructural component and are installed in many modern buildings;therefore,an evaluation of their seismic performance is important and cannot be ignored.To investigate the seismic performance of large-sized high performance concrete cladding(HPCC),a series of full-scale experimental tests were conducted using a unidirectional shaking table.A steel supporting frame was used to install the HPCCs and reproduce the effects of the building under earthquake.The tests were divided into two parts:in-plane(IP)testing and out-plane(OP)testing.Three recorded accelerograms,one artificial accelerogram,and one sinusoidal accelerogram were used to conduct the shaking table tests.The results show that the maximum recorded IP responses of acceleration and interstory drift ratio were 1.04 g and 1/97,while the OP responses were 1.02 g and 1/51.The HPCCs functioned well throughout the entire experimental protocol.The fundamental frequency of the HPCCs systems rarely changed after the tests.展开更多
Earthquakes are critical triggers for slope instability.While extensive research has been conducted on slope failure modes under seismic loading,the identification of sliding surface propagation and coalescence remain...Earthquakes are critical triggers for slope instability.While extensive research has been conducted on slope failure modes under seismic loading,the identification of sliding surface propagation and coalescence remains insufficiently explored.This study investigates the dynamic response of a deposit slope containing a weak interlayer through large-scale shaking table tests.The propagation process of the sliding surface was identified using the Hilbert-Huang transform and marginal spectrum analysis.Under seismic excitation,sliding occurs along the interface between the overburden and the weak interlayer,leading to sudden landslide events.Differential vibrations at the overburden-weak interlayer-bedrock interfaces are identified as a primary mechanism driving landslide initiation.As input acceleration increases,these interfacial vibration contrasts intensify,and the acceleration amplification effect within the overburden becomes markedly pronounced.Following landslide occurrence,the vibration differences across interfaces decrease sharply.In the time-frequency domain,seismic waves transmitted through the weak interlayer exhibit amplified low-frequency components.Marginal spectrum analysis of seismic energy evolution within the slope reveals that energy attenuation in the 19-22 Hz frequency band correlates with landslide occurrence,while attenuation in the 9-11 Hz band serves as an indicator for sliding surface propagation and coalescence.For seismic design of deposit slopes with weak interlayers,particular attention should be given to the increased seismic inertial forces in the overburden layer and the detrimental effects of low-frequency wave components on sliding surface development.展开更多
Towards line speed and accurateness on-line content popularity monitoring on Content Centric Networking(CCN) routers, we propose a three-stage scheme based on Bloom filters and hash tables for differentiated traffic. ...Towards line speed and accurateness on-line content popularity monitoring on Content Centric Networking(CCN) routers, we propose a three-stage scheme based on Bloom filters and hash tables for differentiated traffic. At the first stage, we decide whether to deliver the content to the next stage depending on traffic types. The second stage consisting of Standard Bloom filters(SBF) and Counting Bloom filters(CBF) identifies the popular content. Meanwhile, a scalable sliding time window based monitoring scheme for different traffic types is proposed to implement frequent and real-time updates by the change of popularities. Hash tables according with sliding window are used to record the popularity at the third stage. Simulation results reveal that this method reaches a 40 Gbps processing speed at lower error probability with less memory, and it is more sensitive to the change of popularity. Additionally, the architecture which can be implemented in CCN router is flexible and scalable.展开更多
Ground-penetrating radar (GPR) has been used predominantly for environments with low electrical conductivity like freshwater aquifers, glaciers, or dry sandy soils. The objective of the present study was to explore it...Ground-penetrating radar (GPR) has been used predominantly for environments with low electrical conductivity like freshwater aquifers, glaciers, or dry sandy soils. The objective of the present study was to explore its application for mapping in subsurface agricultural soils to a depth of several meters. For a loamy sand and a clayey site on the North China Plain, clay inclusions in the sand were detected; the thickness, inclination, and continuity of the confining clay and silt layers was assessed; and a local water table was mapped. Direct sampling (soil coring and profiling) in the top meter and independent measurement of the water table were utilized to confirm the findings. Also, effective estimates of the dielectric number for the site with the dielectric number of moist clayey soils depending strongly on frequency were obtained. Thus, important properties of soils, like the arrangement and type of layers and in particular their continuity and inclination, could be explored with moderate efforts for rather large areas to help find optimal locations for the time-consuming and expensive measurements which would be necessary to detail a model of the subsurface.展开更多
Several growth models were selected to fit data of dahurian larch plantations using nonlinear regression analysis. The best models were used to construct the site index table' the 2-way volume table and the growth...Several growth models were selected to fit data of dahurian larch plantations using nonlinear regression analysis. The best models were used to construct the site index table' the 2-way volume table and the growth process table. The Chapman-Richards equation is the best model used as the guide curve to form the site index table for dahurian larch plantations.展开更多
The fall armyworm(FAW),Spodoptera frugiperda Smith(Lepidoptera:Noctuidae)is an important agricultural pest that invaded China in the middle of December 2018.As a polyphagous pest,FAW is identified as a serious threat ...The fall armyworm(FAW),Spodoptera frugiperda Smith(Lepidoptera:Noctuidae)is an important agricultural pest that invaded China in the middle of December 2018.As a polyphagous pest,FAW is identified as a serious threat to agricultural production and food security in China.Pepper(Capsicum annuum L.),tomato(Solanum lycopersicum Mill.)and eggplant(Solanum melongena L.)are three of dominant solanaceous vegetables of this country.To our knowledge,the effects of these plants on the performances of FAW have not been well studied.In this study we assessed the fitness of this pest to these three plants.Results showed that FAW can complete its life cycle when fed with tomato and pepper,but not on eggplant.The population parameters of FAW fed with maize(Zea mays L.)and the three solanaceous vegetables were compared using the age-stage,two-sex life table method.Developmental duration was significantly different in the larval stage,but not in the pupae stage.FAW fed with pepper had the longest pre-adult period(41.73 d)and the lightest pupal weight(0.1134 g);the survival rate was lower than FAW fed with tomato.Significant differences were observed in the mean fecundity of female,with the highest(943.95 eggs)laid by FAW fed with tomato.FAW had the shortest mean generation time(T),the highest intrinsic rate of increase(r)and finite rate of increase(λ)on maize,and the highest net reproductive rate(R_(0))on tomato.Overall,FAW fitness on the three solanaceous vegetables was:tomato>pepper>eggplant.This study provides the foundation for further assessment of FAW risk to solanaceous vegetables and for establishing corresponding control strategies in China.展开更多
The mineral stability and solute activities of soil solution extracted from selected horizons of seven studied pedons of Alfisols in Kentucky, USA, and the relationship between distribution of iron-manganese concretio...The mineral stability and solute activities of soil solution extracted from selected horizons of seven studied pedons of Alfisols in Kentucky, USA, and the relationship between distribution of iron-manganese concretions and the restrictive layers were investigated. The results showed that the genesis and development of these soils and mineral weathering trends were strongly influenced by the depth of bedrock and the presence of perched water tables at lithic (limestone) interfaces due to the dissolution and buffering effect of limestone bedrock. The extractable Mg/Ca ratio as depth function and soil depth above bedrock could be used as indices of weathering and degree of soil development. Maximum iron-manganese concretion accumulation was found to occur in the horizon overlying clay horizon (>40% clay) with a sharp increase in clay content (>10%), which suggested that zones of Fe-Mn concretion accumulation in soils of the Inner Bluegrass Region appeared to be a sensitive genetic indicator of argillic horizons with restrictive permeability.展开更多
文摘The development of any analytical method should have to experience at least four stages: its initial status, growth, mature and declining. However, although the regional input-output analysis has been widely applied for more than forty years, it is still one of the most important approach in regional economic analysis and forecast at present in the world. This is due to the never ended modifications and its great potentials. In this paper, we review the historical development of the regional input-output analysis.
基金supported by National Natural Science Foundation of China(72471007)Beijing Municipal Social Science Foundation Planning Project(23ZGB005)Humanities and Social Science Foundation of Ministry of Education of the People's Republic of China(Grant No.23YJAZH041).
文摘Purpose:The study evaluates the relative roles of Domestic-Funded Enterprises(DFEs)and Foreign-Funded Enterprises(FFEs)across Chinese provinces.It further examines how industrial structures differ by ownership at both regional and national scales.Drawing on these findings,the analysis traces the geographic shift of FFEs and offers evidence-based guidance for shaping foreign investment policy.Design/methodology/approach:This study uses Inter-Country Input-Output(ICIO)and Inter-Region Input-Output(IRIO)tables to build two extended datasets:Ownership-Extended Inter-Country Input-Output(OE-ICIO)and Ownership-Extended Multi-Region Input-Output(OE-IRIO)tables.These are then combined to construct the Regionally-Ownership Dually-Extended Multi-Regional Input-Output(RODE-MRIO)table and Global Domestic and Foreign Enterprises Network(GDFEN)model to explore the industrial relocation trends of FFEs in China.Findings:The results indicate that:(1)From 2010 to 2019,FFEs in China showed an overall decline in influence,profitability,and network robustness.(2)Eastern and developed regions saw a clear retreat of FFEs,with a shift toward domestic control.Central regions and more developed regions played a transitional role.Moreover,western and less developed regions remained stable but still relied on low-end and resource-based activities.(3)FFEs’influence has been gradually shifting towards less-developed central and western provinces due to rising labor costs and stricter environmental regulations.Research limitations:First,only general policy recommendations are proposed,without exploring the design of specific policy instruments.Second,the significant impact of recent trade measures on the behavior of FFEs has not been considered.Third,further research is needed to deepen the analysis by comparing regional ownership dynamics in China with those in other major economies.Practical implications:This research provides valuable insights for policymakers aiming to enhance regional economic development and improve China’s position within Global Value Chains(GVCs).Originality/value:The originality of this paper lies in its development of a new model that combines geographic,sectoral,and ownership dimensions.This model allows for a clearer analysis of the roles of foreign and DFEs in China’s regional economy.It offers insights into industrial transfer trends within global value chains and provides a framework for analyzing and forecasting future shifts.
文摘The estimation of regional input-output tables is well discussed in the literature and a large variety of methods exist. In this paper we will use the concept of fundamental economic structure （FES） to estimate the matrix of intermediate deliveries for some ＂missing＂ region（s）. Furthermore, the estimates will be compared with the estimates obtained from ＂traditional＂ estimating techniques, including regionalization on the basis of the national table, and borrowing coefficients from similar regions. The results show FES is very helpful for compiling regional tables of China.
文摘Given the statistical gaps in material flow among provinces in China, a method was introduced to estimate regional physical imports and exports （RPIE）, which includes international and interregional imports/ exports. This method uses provincial monetary input- output tables （MIOT） and international trade statistics. A coefficient matrix representing correlations between monetary value and physical mass for years 2000-2009 was obtained based on a detailed commodity classification and 22 material production sectors in MIOT. With the coefficient matrix as reference, RPIE was measured. Pilot calculation of both regional physical trade balance and domestic material consumption, as well as a brief analysis of these methods, were conducted using 2002 data.
基金supported by the National Key Research and Development Project of China(Nos.2024YFC3713802 and 2023YFC3709700)the Strategic Priority Research Program of the Chinese Academy of Sciences,China(No.XDA23030202)the Science and Technology Program for Foreign Cooperation in Fujian Province of China(No.2022I0040).
文摘The transport behavior of pollutants under dynamic groundwater conditions has attracted significant attention recently.However,there is limited research on the simultaneous effects of groundwater table fluctuations on the transport of co-existing pollutants,especially combined dense and light non-aqueous phase liquids(DNAPLs and LNAPLs).In this study,column experiments investigated toluene and dichloromethane transport in a controlled water table system with varying fluctuation conditions.Results showed that both dichloromethane and toluene accumulated near the groundwater table under static water table conditions,but the concentration of dichloromethane declined more rapidly than toluene due to differences in their physicochemical properties,such as solubility,density,and hydrophobicity.Groundwater fluctuations facilitated pollutants transportation towards deeper layers,potentially resulting in unforeseen increases in pollutant volatilization and downward fluxes.The interactions between dichloromethane and toluene,including competitive adsorption,enhanced dissolution,and altered kinematic viscosities,resulted in the reduced transport potential of dichloromethane while enhancing that of toluene.Furthermore,compared to dichloromethane,the initial upward fluctuation of the water table had a more pronounced impact on toluene due to its lower solubility and volatility.The downward transport risk index assessment indicated that among various factors considered,groundwater fluctuation amplitude exerted the most significant influence on pollutant migration risk.These new findings will provide important insights into understanding and assessment of the potential transport risk associated with combined LNAPLs and DNAPLs in the natural environment.
基金National Key R&D Program of China under Grant No.2024YFD1600404。
文摘Severe failures of nonstructural components have occurred during previous earthquakes.Claddings are one of the most widely used nonstructural component and are installed in many modern buildings;therefore,an evaluation of their seismic performance is important and cannot be ignored.To investigate the seismic performance of large-sized high performance concrete cladding(HPCC),a series of full-scale experimental tests were conducted using a unidirectional shaking table.A steel supporting frame was used to install the HPCCs and reproduce the effects of the building under earthquake.The tests were divided into two parts:in-plane(IP)testing and out-plane(OP)testing.Three recorded accelerograms,one artificial accelerogram,and one sinusoidal accelerogram were used to conduct the shaking table tests.The results show that the maximum recorded IP responses of acceleration and interstory drift ratio were 1.04 g and 1/97,while the OP responses were 1.02 g and 1/51.The HPCCs functioned well throughout the entire experimental protocol.The fundamental frequency of the HPCCs systems rarely changed after the tests.
基金financially supported by the National Key Research&Development Program of China(2025YFE0123800)National Natural Science Foundation of China(No.52372343)+4 种基金Sichuan Transportation Science and Technology Project(2023-A-03)Applied Basic Research Programs of Science and Technology Department in Sichuan Province,China(2022NSFSC1086)Sichuan Science and Technology Program(2024YFHZ0121)the R&D Fund Project of China Academy of Railway Science Corporation Limited(K2024G008)National Natural Science Foundation of China(No.52502430).
文摘Earthquakes are critical triggers for slope instability.While extensive research has been conducted on slope failure modes under seismic loading,the identification of sliding surface propagation and coalescence remains insufficiently explored.This study investigates the dynamic response of a deposit slope containing a weak interlayer through large-scale shaking table tests.The propagation process of the sliding surface was identified using the Hilbert-Huang transform and marginal spectrum analysis.Under seismic excitation,sliding occurs along the interface between the overburden and the weak interlayer,leading to sudden landslide events.Differential vibrations at the overburden-weak interlayer-bedrock interfaces are identified as a primary mechanism driving landslide initiation.As input acceleration increases,these interfacial vibration contrasts intensify,and the acceleration amplification effect within the overburden becomes markedly pronounced.Following landslide occurrence,the vibration differences across interfaces decrease sharply.In the time-frequency domain,seismic waves transmitted through the weak interlayer exhibit amplified low-frequency components.Marginal spectrum analysis of seismic energy evolution within the slope reveals that energy attenuation in the 19-22 Hz frequency band correlates with landslide occurrence,while attenuation in the 9-11 Hz band serves as an indicator for sliding surface propagation and coalescence.For seismic design of deposit slopes with weak interlayers,particular attention should be given to the increased seismic inertial forces in the overburden layer and the detrimental effects of low-frequency wave components on sliding surface development.
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No.61521003)the National Basic Research Program of China (2012CB315901, 2013CB329104)+1 种基金the National Natural Science Foundation of China (Grant No. 61372121, 61309019, 61309020)the National HighTech Research & Development Program of China (Grant No. 2015AA016102, 2013AA013505)
文摘Towards line speed and accurateness on-line content popularity monitoring on Content Centric Networking(CCN) routers, we propose a three-stage scheme based on Bloom filters and hash tables for differentiated traffic. At the first stage, we decide whether to deliver the content to the next stage depending on traffic types. The second stage consisting of Standard Bloom filters(SBF) and Counting Bloom filters(CBF) identifies the popular content. Meanwhile, a scalable sliding time window based monitoring scheme for different traffic types is proposed to implement frequent and real-time updates by the change of popularities. Hash tables according with sliding window are used to record the popularity at the third stage. Simulation results reveal that this method reaches a 40 Gbps processing speed at lower error probability with less memory, and it is more sensitive to the change of popularity. Additionally, the architecture which can be implemented in CCN router is flexible and scalable.
基金Project supported in part by the Deutsche Forschungsgemeinschaft (DFG), Germany (No. RO 1080/8-1) jointly by Max-Planck Gesellschaft and the Chinese Academy of Sciences through a travel grant to the first author.
文摘Ground-penetrating radar (GPR) has been used predominantly for environments with low electrical conductivity like freshwater aquifers, glaciers, or dry sandy soils. The objective of the present study was to explore its application for mapping in subsurface agricultural soils to a depth of several meters. For a loamy sand and a clayey site on the North China Plain, clay inclusions in the sand were detected; the thickness, inclination, and continuity of the confining clay and silt layers was assessed; and a local water table was mapped. Direct sampling (soil coring and profiling) in the top meter and independent measurement of the water table were utilized to confirm the findings. Also, effective estimates of the dielectric number for the site with the dielectric number of moist clayey soils depending strongly on frequency were obtained. Thus, important properties of soils, like the arrangement and type of layers and in particular their continuity and inclination, could be explored with moderate efforts for rather large areas to help find optimal locations for the time-consuming and expensive measurements which would be necessary to detail a model of the subsurface.
文摘Several growth models were selected to fit data of dahurian larch plantations using nonlinear regression analysis. The best models were used to construct the site index table' the 2-way volume table and the growth process table. The Chapman-Richards equation is the best model used as the guide curve to form the site index table for dahurian larch plantations.
基金supported by the Science and Technology Program of Guizhou Province,China([2019]2412)the Basic Research Program(Science and Technology)of Guizhou Province,China([2020]1Z021)。
文摘The fall armyworm(FAW),Spodoptera frugiperda Smith(Lepidoptera:Noctuidae)is an important agricultural pest that invaded China in the middle of December 2018.As a polyphagous pest,FAW is identified as a serious threat to agricultural production and food security in China.Pepper(Capsicum annuum L.),tomato(Solanum lycopersicum Mill.)and eggplant(Solanum melongena L.)are three of dominant solanaceous vegetables of this country.To our knowledge,the effects of these plants on the performances of FAW have not been well studied.In this study we assessed the fitness of this pest to these three plants.Results showed that FAW can complete its life cycle when fed with tomato and pepper,but not on eggplant.The population parameters of FAW fed with maize(Zea mays L.)and the three solanaceous vegetables were compared using the age-stage,two-sex life table method.Developmental duration was significantly different in the larval stage,but not in the pupae stage.FAW fed with pepper had the longest pre-adult period(41.73 d)and the lightest pupal weight(0.1134 g);the survival rate was lower than FAW fed with tomato.Significant differences were observed in the mean fecundity of female,with the highest(943.95 eggs)laid by FAW fed with tomato.FAW had the shortest mean generation time(T),the highest intrinsic rate of increase(r)and finite rate of increase(λ)on maize,and the highest net reproductive rate(R_(0))on tomato.Overall,FAW fitness on the three solanaceous vegetables was:tomato>pepper>eggplant.This study provides the foundation for further assessment of FAW risk to solanaceous vegetables and for establishing corresponding control strategies in China.
基金Project (No. Y97D02061) supported by the Natural Science Foundation of Shandong Province, China.
文摘The mineral stability and solute activities of soil solution extracted from selected horizons of seven studied pedons of Alfisols in Kentucky, USA, and the relationship between distribution of iron-manganese concretions and the restrictive layers were investigated. The results showed that the genesis and development of these soils and mineral weathering trends were strongly influenced by the depth of bedrock and the presence of perched water tables at lithic (limestone) interfaces due to the dissolution and buffering effect of limestone bedrock. The extractable Mg/Ca ratio as depth function and soil depth above bedrock could be used as indices of weathering and degree of soil development. Maximum iron-manganese concretion accumulation was found to occur in the horizon overlying clay horizon (>40% clay) with a sharp increase in clay content (>10%), which suggested that zones of Fe-Mn concretion accumulation in soils of the Inner Bluegrass Region appeared to be a sensitive genetic indicator of argillic horizons with restrictive permeability.
