A class of nonlinear and continuous type Leontief model and its corresponding conditional input-output equation are introduced, and two basic problems under the so called positive or negative boundary assumption are p...A class of nonlinear and continuous type Leontief model and its corresponding conditional input-output equation are introduced, and two basic problems under the so called positive or negative boundary assumption are presented. By approaches of nonlinear analysis some solvability results of this equation and continuous perturbation properties of the relative solution sets are obtained, and some economic significance are illustrated by the remark.展开更多
On the basis of input-output table of Henan Province and China in 2007,this paper advances a simple method of constructing two-region input-output model using MRIO model,to research the economic link between the indus...On the basis of input-output table of Henan Province and China in 2007,this paper advances a simple method of constructing two-region input-output model using MRIO model,to research the economic link between the industries of Henan Province and the industries of other regions.I summarize the characteristics of this method based on this as follows:when researching inter-regional economic link,the multi-region or two-region input-output model has prominent superiority,and we can conduct preliminary estimation on the multi-region input-output model using location quotient approach.展开更多
Energy has laid material foundation for human society during its development. Meanwhile, any change of price in the energy industry may influence social production and people’s life at all levels via an input-output ...Energy has laid material foundation for human society during its development. Meanwhile, any change of price in the energy industry may influence social production and people’s life at all levels via an input-output mechanism under which the change related to energy is surely transmitted to other industries. The price change thus incurred in all industries may adversely affect the realization of macroeconomic objective-maintaining prices at a stable level. It is, therefore, needed to conduct an empirical research related to the impact of price change in energy industry on that in other industries. According to the data coming from “China’s 2015 Input-Output Extension Table (42 Departments)” and four hypothetical basis, this article focuses on four energy sectors and analyzes how deeply the price change of them, by use of input-output model, affects that of other industrial products under five conditions where each of their price rises by 10% individually or simultaneously, and why such an influence occurs. The results show that the price rising of the energies in question leads to an upward growth in the prices of other industrial products, especially when their prices go up simultaneously. Besides, the price increase in the four energy sectors doesn’t influence other industries in an accumulation form but actually leads to a rollback in some of other industries. It is recommended to adopt diversified pricing strategies for different energy products, thus maximizing the value of each specific energy, and meanwhile achieving the goals of energy consumption reduction and price equilibrium.展开更多
Based on a refined ＂non-competitive input-output model,＂ this paper proposes a new framework for analyzing the status of a country＇s high-tech industries in the international division of labor, i.e. calculates the ...Based on a refined ＂non-competitive input-output model,＂ this paper proposes a new framework for analyzing the status of a country＇s high-tech industries in the international division of labor, i.e. calculates the index of＂ weighted value-added productivity ＂ by compiling non-competitive input-output tables which distinguish high-tech industries from traditional industries. The new method effectively avoids ＂statistical illusion＂ which stems from a biased focus on gross exports under intra-product specialization. The empirical study shows that since 1995, the status of China＇s high-tech industries has grown quickly as a result of enhanced labor productivity, but still lags behind those of major developed countries. In addition, the study also suggests that the status of China＇s high-tech industries has been over-estimated using the traditional gross export statistical method.展开更多
To promote sustainability, it has become increasingly vital to properly account material and energy flows in industrial production processes. Therefore, a generic process-level input-output （IO） model was developed ...To promote sustainability, it has become increasingly vital to properly account material and energy flows in industrial production processes. Therefore, a generic process-level input-output （IO） model was developed to provide an integrated energy （material） accounting and analysis approach for industrial production processes. By extending the existing processlevel IO models, the production, usage, export and loss of by-products were explicitly considered in the proposed IO model. Moreover, the by-products allocation procedures were incorporated into the proposed IO model to reflect individual contributions of products to energy consumption. Finally, the proposed model enabled calculating embodied energy of main products and total energy consumption under hierarchical accounting scope. Plant managers, energy management consultants, governmental officials and academic researchers could use this input-output model to account material and energy flows, thus calculating energy consumption indicators of a production process with their specific system boundary requirements. The accounting results could be further used for energy labeling, identifying bottlenecks of production activities, evaluating industrial symbiosis effects, improving materials and energy utilization efficiency, etc. The model could also be used as a planning tool to determine the effect that a particular change of technology and supply chains may have on the industrial production processes. The proposed model was tested and applied in a real integrated steel mill, which also provided the reference results for related researches. At last, some concepts, computational issues and limi- tations of the proposed model were discussed.展开更多
The method of compiling input-output models of science and technology was studied,and the application of input-output techniques in evaluating the progress of enterprise science and technology was discussed.And the mo...The method of compiling input-output models of science and technology was studied,and the application of input-output techniques in evaluating the progress of enterprise science and technology was discussed.And the models for determining direct,indirect and full contributions of the progress of enterprise science and technology have been set up which can be used to analyse and evaluate the direct,indirect and full benefits of the progress of enterprise science and technology.展开更多
The input-output pollution control model given in [1] is generalized. The generalization makes it easier for the model to handle many problem instances. A linear program is used to solve the new model. An example is g...The input-output pollution control model given in [1] is generalized. The generalization makes it easier for the model to handle many problem instances. A linear program is used to solve the new model. An example is given to show that the new model can handle classes of problems that the original model cannot handle.展开更多
Agricultural input and output status in southern Xinjiang,China is introduced,such as lack of agricultural input,low level of agricultural modernization,excessive fertilizer use,serious damage of environment,shortage ...Agricultural input and output status in southern Xinjiang,China is introduced,such as lack of agricultural input,low level of agricultural modernization,excessive fertilizer use,serious damage of environment,shortage of water resources,tremendous pressure on ecological balance,insignificant economic and social benefits of agricultural production in southern Xinjiang,agriculture remaining a weak industry,agricultural economy as the economic subject of southern Xinjiang,and backward economic development of southern Xinjiang.Taking the Aksu area as an example,according to the input and output data in the years 2002-2007,input-output model about regional agriculture of the southern Xinjiang is established by principal component analysis.DPS software is used in the process of solving the model.Then,Eviews software is adopted to revise and test the model in order to analyze and evaluate the economic significance of the results obtained,and to make additional explanations of the relevant model.Since the agricultural economic output is seriously restricted in southern Xinjiang at present,the following countermeasures are put forward,such as adjusting the structure of agricultural land,improving the utilization ratio of land,increasing agricultural input,realizing agricultural modernization,rationally utilizing water resources,maintaining eco-environmental balance,enhancing the awareness of agricultural insurance,minimizing the risk and loss,taking the road of industrialization of characteristic agricultural products,and realizing the transfer of surplus labor force.展开更多
Cable robots are structurally the same as parallel robots but with the basic difference that cables can only pull the platform and cannot push it. This feature makes control of cable robots a lot more challenging comp...Cable robots are structurally the same as parallel robots but with the basic difference that cables can only pull the platform and cannot push it. This feature makes control of cable robots a lot more challenging compared to parallel robots. This paper introduces a controller for cable robots under force constraint. The controller is based on input-output linearization and linear model predictive control. Performance of input-output linearizing (IOL) controllers suffers due to constraints on input and output variables. This problem is successfully tackled by augmenting IOL controllers with linear model predictive controller (LMPC). The effecttiveness of the proposed method is illustrated by numerical simulation.展开更多
China has huge differences among its regions in terms of socio-economic development, industrial structure, natural resource endowments, and technological advancement. These differences have created complicated linkage...China has huge differences among its regions in terms of socio-economic development, industrial structure, natural resource endowments, and technological advancement. These differences have created complicated linkages between regions in China. In this study, building upon gravity model and location quotient techniques, we develop a sector-specific model to estimate inter-provincial trade flows, which is the base for making a multi-regional input-output table. In the model, we distinguish sectors with less intra-sector input from those with larger intra-sector input, and assume that the former sectors tend to compete among regions while the latter tend to cooperate among regions. Then we apply this new method of inter-regional trade estimation to three sectors： food and tobacco, metal smelting and proc- essing, and electrical equipment. The results show that selection of bandwidth has a significant impact on the assessment of inter-regional trade. Trade flows are more scattered with the increase of bandwidths. As a result, bandwidth reflects the spatial concentration of geo- graphical activities, which should be distinguishable for different industries. We conclude that the sector-specific spatial model can increase the credibility of estimates of inter-regional trade flows.展开更多
The article used general equilibrium model to analyze the change of gross domestic product and industry output affected by water resources policies in Beijing City by using GEMPACK soft tool.The article researches on ...The article used general equilibrium model to analyze the change of gross domestic product and industry output affected by water resources policies in Beijing City by using GEMPACK soft tool.The article researches on rules of water supply and demand,evaluating water resources,building water resources input and output table,establishing water computable general equilibrium model and stimulating water policy.The stimulation gives a scenario that increases water price by 10%.The result shows the following aspects.First,water resources policy infects gross domestic product and industry output in different ways.There are different behaviors in different industries as to the water policy. Agriculture industry has the same tendency as water price change and it has more sensitive to water quantity than to water price.For basic energy industries such as oil and chemistry and gas,they show diversity tendency.As to some high water consumer industry such as paper and textile etc.,water resource economic policy can infect them greatly and can promote them to accomplish more water-saving technology.Waste water and construction and service industries show the same tendency as to water policy.Second,government should pay more attention to water resource policy by macro economic administration.The simulation also shows that the output and supply and consumer price change more than expect as to water policy in a free market economic in water industry.So as to a government policy maker,one should be more carefully and prepare suitable forecast and plan to water policy and its negative impact.展开更多
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
We establish the two-sector economy model including the urban sector and the rural sector, derive the labor demand curve of the urban sector and rural sector under the condition of balanced production decisions with b...We establish the two-sector economy model including the urban sector and the rural sector, derive the labor demand curve of the urban sector and rural sector under the condition of balanced production decisions with benefit maximization, and analyze the labor flow when in the short-term or long-term two-sector economic equilibrium. The results show that rising wages caused by short-term internal and external impact increases the pressure on the employment in two sectors, and the urban sector is difficult to absorb the surplus labor of the rural sector. However, under the conditions of free flow of factors and fully competitive market, the wage variation arising from the long-term endogenous evolution, leads to inversely proportional relationship between the demand for labor in the urban and rural sectors, which is conducive to the transfer of rural labor force. Based on microeconomic survey data of labor flow in urban-rural coordination experimental zones in Chongqing City, this paper makes an empirical study of the main factors having a short-term impact on the labor transfer, and the results show that education level and the opportunity to participate in the training are important factors.展开更多
In this paper, we attempted to calculate the impact of environmental regulation on the international competitiveness of China＇s industries. Calculations are based on the input-output model that incorporates pollution...In this paper, we attempted to calculate the impact of environmental regulation on the international competitiveness of China＇s industries. Calculations are based on the input-output model that incorporates pollution control costs. We took enterprises ＇pollution control costs as the substitute variable for environmental regulation and price changes to measure the impact on international competitiveness for all sectors. Our studies reported three findings. First, price rises caused by pollution control costs were not more than 4 per cent in the manufacturing and trade sectors in 2007. Second, although the charging rate on pollutant discharge has become increasingly higher since 2003, the resultant price rise is only around O. 5 per cent across all sectors. Third, the impact brought about by increasingly stronger environmental regulation is limited and the resultant price rise does not exceed 2 per cent. Thesefindings indicate that the impact of environmental regulation on China＇s trade sectors is affordable. Therefore, it is needless to worry that environmental regulation will weaken the international competitiveness of Chinese products.展开更多
By introducing virtual water(VW)flow correlation coefficients and risk indicators,this study examines the VW transmission relationship between urban agglomerations and cities in the Yellow River Basin(YRB)and its impa...By introducing virtual water(VW)flow correlation coefficients and risk indicators,this study examines the VW transmission relationship between urban agglomerations and cities in the Yellow River Basin(YRB)and its impact on regional water resources pressure.The results show that:except for the Shandong Peninsula Urban Agglomeration(SPUA)and Central Plains Urban Agglomeration(CPUA),the other urban agglomerations primarily act as VW exporting regions,while virtual water-importing cities are concentrated in the eastern regions.Notably,the Ningxia Urban Agglomeration(NUA)demonstrates significantly higher VW impact and sensitivity coefficients values than the remaining six urban agglomerations.First-tier cities generally display lower virtual water impact and sensitivity coefficients,whereas emerging cities exhibit the opposite trend.Additionally,we observe uneven risk variations between VW importing and exporting regions.Taking NUA as an example,the risk increase resulting from VW exports significantly exceeds the risk reduction associated with VW imports in the corresponding regions.It’s important to highlight that first-tier cities consistently decrease water resource risk through VW imports in the study years.However,among second and third-tier cities,only 38.9%experience reduced water resource risk through VW imports.Therefore,we recommend a focused examination of VW imports and exports in western region urban agglomerations,cities,and second and third-tier cities within the watershed.Leveraging virtual water’s asymmetric and high-value transfer can alleviate water resource pressure and scarcity risks in high-pressure regions by shifting them to lower-pressure regions,thus mitigating water resource stress across regions.展开更多
The present study develops a data-based compact model for the prediction of the fluid temperature evolution in district heating-and-cooling pipeline networks.This model is based on an existing“reduced-order model”by...The present study develops a data-based compact model for the prediction of the fluid temperature evolution in district heating-and-cooling pipeline networks.This model is based on an existing“reduced-order model”by the authors obtained from reduction of the“full-order model”describing the spatio-temporal energy balance for each pipe segment to a semi-analytical input-output relation between the pipe outlet temperature and the pipe inlet and ground temperatures.The proposed model(denoted XROM)expands on the original reduced-order model by incorporating variable mass flux as an additional input and thus greatly increases its practical relevance.The XROM represents variable mass flux by step-wise switching between mass-flux levels and thereby induces a prediction error relative to the true full-order model evolution after each switching.Theoretical analysis rigorously demonstrates that this error always decays and the XROM invariably converges on the full-order model evolution and,consequently,affords the same prediction accuracy.Performance analyses reveal that prediction errors are restricted to short“convergence intervals”after each mass-flux switching and the XROM therefore can handle substantially faster operating schemes than the current ones based on hourly monitoring and control.Convergence intervals of O(minutes)are namely typically sufficient-and thus switching frequencies up to O(minutes 1)permissible during dynamic operation and control actions-for reliable predictions.Quantification of these convergence intervals by an easy-to-use empirical relation furthermore enables a priori determination of the conditions for reliable predictions.Moreover,the XROM can capture the full 3D system dynamics(provided incompressible flow and heat-transfer mechanisms depending linearly on temperature)versus the essentially 1D approximation of current compact pipe models yet at similar computational cost.These attributes advance(parts of)district heating and cooling networks demanding prediction accuracies beyond 1D as its primary application area.This makes the XROM complementary to said pipe models and thereby expands the modelling capabilities for handling the growing complexity of(next-generation)networks.展开更多
文摘A class of nonlinear and continuous type Leontief model and its corresponding conditional input-output equation are introduced, and two basic problems under the so called positive or negative boundary assumption are presented. By approaches of nonlinear analysis some solvability results of this equation and continuous perturbation properties of the relative solution sets are obtained, and some economic significance are illustrated by the remark.
基金Supported by Project of Henan Provincial Department of Science and Technology(112400410017)Project of Henan Provincial Department of Education(2010-QN-008)
文摘On the basis of input-output table of Henan Province and China in 2007,this paper advances a simple method of constructing two-region input-output model using MRIO model,to research the economic link between the industries of Henan Province and the industries of other regions.I summarize the characteristics of this method based on this as follows:when researching inter-regional economic link,the multi-region or two-region input-output model has prominent superiority,and we can conduct preliminary estimation on the multi-region input-output model using location quotient approach.
文摘Energy has laid material foundation for human society during its development. Meanwhile, any change of price in the energy industry may influence social production and people’s life at all levels via an input-output mechanism under which the change related to energy is surely transmitted to other industries. The price change thus incurred in all industries may adversely affect the realization of macroeconomic objective-maintaining prices at a stable level. It is, therefore, needed to conduct an empirical research related to the impact of price change in energy industry on that in other industries. According to the data coming from “China’s 2015 Input-Output Extension Table (42 Departments)” and four hypothetical basis, this article focuses on four energy sectors and analyzes how deeply the price change of them, by use of input-output model, affects that of other industrial products under five conditions where each of their price rises by 10% individually or simultaneously, and why such an influence occurs. The results show that the price rising of the energies in question leads to an upward growth in the prices of other industrial products, especially when their prices go up simultaneously. Besides, the price increase in the four energy sectors doesn’t influence other industries in an accumulation form but actually leads to a rollback in some of other industries. It is recommended to adopt diversified pricing strategies for different energy products, thus maximizing the value of each specific energy, and meanwhile achieving the goals of energy consumption reduction and price equilibrium.
文摘Based on a refined ＂non-competitive input-output model,＂ this paper proposes a new framework for analyzing the status of a country＇s high-tech industries in the international division of labor, i.e. calculates the index of＂ weighted value-added productivity ＂ by compiling non-competitive input-output tables which distinguish high-tech industries from traditional industries. The new method effectively avoids ＂statistical illusion＂ which stems from a biased focus on gross exports under intra-product specialization. The empirical study shows that since 1995, the status of China＇s high-tech industries has grown quickly as a result of enhanced labor productivity, but still lags behind those of major developed countries. In addition, the study also suggests that the status of China＇s high-tech industries has been over-estimated using the traditional gross export statistical method.
文摘To promote sustainability, it has become increasingly vital to properly account material and energy flows in industrial production processes. Therefore, a generic process-level input-output （IO） model was developed to provide an integrated energy （material） accounting and analysis approach for industrial production processes. By extending the existing processlevel IO models, the production, usage, export and loss of by-products were explicitly considered in the proposed IO model. Moreover, the by-products allocation procedures were incorporated into the proposed IO model to reflect individual contributions of products to energy consumption. Finally, the proposed model enabled calculating embodied energy of main products and total energy consumption under hierarchical accounting scope. Plant managers, energy management consultants, governmental officials and academic researchers could use this input-output model to account material and energy flows, thus calculating energy consumption indicators of a production process with their specific system boundary requirements. The accounting results could be further used for energy labeling, identifying bottlenecks of production activities, evaluating industrial symbiosis effects, improving materials and energy utilization efficiency, etc. The model could also be used as a planning tool to determine the effect that a particular change of technology and supply chains may have on the industrial production processes. The proposed model was tested and applied in a real integrated steel mill, which also provided the reference results for related researches. At last, some concepts, computational issues and limi- tations of the proposed model were discussed.
文摘The method of compiling input-output models of science and technology was studied,and the application of input-output techniques in evaluating the progress of enterprise science and technology was discussed.And the models for determining direct,indirect and full contributions of the progress of enterprise science and technology have been set up which can be used to analyse and evaluate the direct,indirect and full benefits of the progress of enterprise science and technology.
文摘The input-output pollution control model given in [1] is generalized. The generalization makes it easier for the model to handle many problem instances. A linear program is used to solve the new model. An example is given to show that the new model can handle classes of problems that the original model cannot handle.
基金Supported by the Key Research Subject of Economic Census of Xinjiang Production and Construction Corps(201004)the President Fund for Natural Science Project of Tarim University(TDZKSS09010)+1 种基金the Quality Project of Tarim University(TDZGKC09085)the Quality Project of Tarim University(TDZGTD09004)
文摘Agricultural input and output status in southern Xinjiang,China is introduced,such as lack of agricultural input,low level of agricultural modernization,excessive fertilizer use,serious damage of environment,shortage of water resources,tremendous pressure on ecological balance,insignificant economic and social benefits of agricultural production in southern Xinjiang,agriculture remaining a weak industry,agricultural economy as the economic subject of southern Xinjiang,and backward economic development of southern Xinjiang.Taking the Aksu area as an example,according to the input and output data in the years 2002-2007,input-output model about regional agriculture of the southern Xinjiang is established by principal component analysis.DPS software is used in the process of solving the model.Then,Eviews software is adopted to revise and test the model in order to analyze and evaluate the economic significance of the results obtained,and to make additional explanations of the relevant model.Since the agricultural economic output is seriously restricted in southern Xinjiang at present,the following countermeasures are put forward,such as adjusting the structure of agricultural land,improving the utilization ratio of land,increasing agricultural input,realizing agricultural modernization,rationally utilizing water resources,maintaining eco-environmental balance,enhancing the awareness of agricultural insurance,minimizing the risk and loss,taking the road of industrialization of characteristic agricultural products,and realizing the transfer of surplus labor force.
文摘Cable robots are structurally the same as parallel robots but with the basic difference that cables can only pull the platform and cannot push it. This feature makes control of cable robots a lot more challenging compared to parallel robots. This paper introduces a controller for cable robots under force constraint. The controller is based on input-output linearization and linear model predictive control. Performance of input-output linearizing (IOL) controllers suffers due to constraints on input and output variables. This problem is successfully tackled by augmenting IOL controllers with linear model predictive controller (LMPC). The effecttiveness of the proposed method is illustrated by numerical simulation.
基金National Science Foundation for Distinguished Young Scholars of China, No.41125005
文摘China has huge differences among its regions in terms of socio-economic development, industrial structure, natural resource endowments, and technological advancement. These differences have created complicated linkages between regions in China. In this study, building upon gravity model and location quotient techniques, we develop a sector-specific model to estimate inter-provincial trade flows, which is the base for making a multi-regional input-output table. In the model, we distinguish sectors with less intra-sector input from those with larger intra-sector input, and assume that the former sectors tend to compete among regions while the latter tend to cooperate among regions. Then we apply this new method of inter-regional trade estimation to three sectors： food and tobacco, metal smelting and proc- essing, and electrical equipment. The results show that selection of bandwidth has a significant impact on the assessment of inter-regional trade. Trade flows are more scattered with the increase of bandwidths. As a result, bandwidth reflects the spatial concentration of geo- graphical activities, which should be distinguishable for different industries. We conclude that the sector-specific spatial model can increase the credibility of estimates of inter-regional trade flows.
基金Project supported by the Natural Science Foundation of China(Grant no.40730632/40671035)the Special Fund of Ministry of Science and Technology,China(Grant no. 2006DFA21890)the Key Project of International Cooperation in CAS (Grant no.GJHZ06)
文摘The article used general equilibrium model to analyze the change of gross domestic product and industry output affected by water resources policies in Beijing City by using GEMPACK soft tool.The article researches on rules of water supply and demand,evaluating water resources,building water resources input and output table,establishing water computable general equilibrium model and stimulating water policy.The stimulation gives a scenario that increases water price by 10%.The result shows the following aspects.First,water resources policy infects gross domestic product and industry output in different ways.There are different behaviors in different industries as to the water policy. Agriculture industry has the same tendency as water price change and it has more sensitive to water quantity than to water price.For basic energy industries such as oil and chemistry and gas,they show diversity tendency.As to some high water consumer industry such as paper and textile etc.,water resource economic policy can infect them greatly and can promote them to accomplish more water-saving technology.Waste water and construction and service industries show the same tendency as to water policy.Second,government should pay more attention to water resource policy by macro economic administration.The simulation also shows that the output and supply and consumer price change more than expect as to water policy in a free market economic in water industry.So as to a government policy maker,one should be more carefully and prepare suitable forecast and plan to water policy and its negative impact.
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 Key Project of the National Social Science Fund(12ASH004)National Soft Science Research Project(2008GXQ6D172)+3 种基金National Soft Science Fund Project(2007GXS3D094)Social Science Planning Fund,Ministry of Education(07JA790104)Chongqing Social Science Planning Project(2010YBJJ13)the Fundamental Research Funds for the Central Universities(XDJK2010C103)
文摘We establish the two-sector economy model including the urban sector and the rural sector, derive the labor demand curve of the urban sector and rural sector under the condition of balanced production decisions with benefit maximization, and analyze the labor flow when in the short-term or long-term two-sector economic equilibrium. The results show that rising wages caused by short-term internal and external impact increases the pressure on the employment in two sectors, and the urban sector is difficult to absorb the surplus labor of the rural sector. However, under the conditions of free flow of factors and fully competitive market, the wage variation arising from the long-term endogenous evolution, leads to inversely proportional relationship between the demand for labor in the urban and rural sectors, which is conducive to the transfer of rural labor force. Based on microeconomic survey data of labor flow in urban-rural coordination experimental zones in Chongqing City, this paper makes an empirical study of the main factors having a short-term impact on the labor transfer, and the results show that education level and the opportunity to participate in the training are important factors.
文摘In this paper, we attempted to calculate the impact of environmental regulation on the international competitiveness of China＇s industries. Calculations are based on the input-output model that incorporates pollution control costs. We took enterprises ＇pollution control costs as the substitute variable for environmental regulation and price changes to measure the impact on international competitiveness for all sectors. Our studies reported three findings. First, price rises caused by pollution control costs were not more than 4 per cent in the manufacturing and trade sectors in 2007. Second, although the charging rate on pollutant discharge has become increasingly higher since 2003, the resultant price rise is only around O. 5 per cent across all sectors. Third, the impact brought about by increasingly stronger environmental regulation is limited and the resultant price rise does not exceed 2 per cent. Thesefindings indicate that the impact of environmental regulation on China＇s trade sectors is affordable. Therefore, it is needless to worry that environmental regulation will weaken the international competitiveness of Chinese products.
基金supported by the National Natural Science Foundation of China(Grant No.42201302)the“Double First-Class”University Construction Project of Lanzhou University(Grant No.561120213)the Graduate Research Funding Project of Northwest Normal University(Grant No.2022KYZZ-S195).
文摘By introducing virtual water(VW)flow correlation coefficients and risk indicators,this study examines the VW transmission relationship between urban agglomerations and cities in the Yellow River Basin(YRB)and its impact on regional water resources pressure.The results show that:except for the Shandong Peninsula Urban Agglomeration(SPUA)and Central Plains Urban Agglomeration(CPUA),the other urban agglomerations primarily act as VW exporting regions,while virtual water-importing cities are concentrated in the eastern regions.Notably,the Ningxia Urban Agglomeration(NUA)demonstrates significantly higher VW impact and sensitivity coefficients values than the remaining six urban agglomerations.First-tier cities generally display lower virtual water impact and sensitivity coefficients,whereas emerging cities exhibit the opposite trend.Additionally,we observe uneven risk variations between VW importing and exporting regions.Taking NUA as an example,the risk increase resulting from VW exports significantly exceeds the risk reduction associated with VW imports in the corresponding regions.It’s important to highlight that first-tier cities consistently decrease water resource risk through VW imports in the study years.However,among second and third-tier cities,only 38.9%experience reduced water resource risk through VW imports.Therefore,we recommend a focused examination of VW imports and exports in western region urban agglomerations,cities,and second and third-tier cities within the watershed.Leveraging virtual water’s asymmetric and high-value transfer can alleviate water resource pressure and scarcity risks in high-pressure regions by shifting them to lower-pressure regions,thus mitigating water resource stress across regions.
文摘The present study develops a data-based compact model for the prediction of the fluid temperature evolution in district heating-and-cooling pipeline networks.This model is based on an existing“reduced-order model”by the authors obtained from reduction of the“full-order model”describing the spatio-temporal energy balance for each pipe segment to a semi-analytical input-output relation between the pipe outlet temperature and the pipe inlet and ground temperatures.The proposed model(denoted XROM)expands on the original reduced-order model by incorporating variable mass flux as an additional input and thus greatly increases its practical relevance.The XROM represents variable mass flux by step-wise switching between mass-flux levels and thereby induces a prediction error relative to the true full-order model evolution after each switching.Theoretical analysis rigorously demonstrates that this error always decays and the XROM invariably converges on the full-order model evolution and,consequently,affords the same prediction accuracy.Performance analyses reveal that prediction errors are restricted to short“convergence intervals”after each mass-flux switching and the XROM therefore can handle substantially faster operating schemes than the current ones based on hourly monitoring and control.Convergence intervals of O(minutes)are namely typically sufficient-and thus switching frequencies up to O(minutes 1)permissible during dynamic operation and control actions-for reliable predictions.Quantification of these convergence intervals by an easy-to-use empirical relation furthermore enables a priori determination of the conditions for reliable predictions.Moreover,the XROM can capture the full 3D system dynamics(provided incompressible flow and heat-transfer mechanisms depending linearly on temperature)versus the essentially 1D approximation of current compact pipe models yet at similar computational cost.These attributes advance(parts of)district heating and cooling networks demanding prediction accuracies beyond 1D as its primary application area.This makes the XROM complementary to said pipe models and thereby expands the modelling capabilities for handling the growing complexity of(next-generation)networks.
