With ever increasing water demands and the continuous intensification of water scarcity arising from China's industrialization, the country is struggling to harmonize its industrial development and water supply. This...With ever increasing water demands and the continuous intensification of water scarcity arising from China's industrialization, the country is struggling to harmonize its industrial development and water supply. This paper presents a systems analysis of water with- drawals by Chinese industry and investigates demand- driven industrial water uses embodied in final demand and interregional trade based on a multi-regional input-output model. In 2007, the Electric Power, Steam, and Hot Water Production and Supply sector ranks first in direct industrial water withdrawal (DWW), and Construction has the largest embodied industrial water use (EWU). Investment, consumption, and exports contribute to 34.6%, 33.3%, and 30.6% of the national total EWU, respectively. Specifically, 58.0%, 51.1%, 48.6%, 43.3%, and 37.5% of the regional EWUs respectively in Guangdong, Shanghai, Zhejiang, Jiangsu, and Fujian are attributed to international exports. The total interregional import/export of embodied water is equivalent to about 40% of the national total DWW, of which 55.5% is associated with the DWWs of Electric Power, Steam, and Hot Water Production and Supply. Jiangsu is the biggest interregional exporter and deficit receiver of embodied water, in contrast to Guangdong as the biggest interregional importer and surplus receiver. Without implementing effective water- saving measures and adjusting industrial structures, the regional imbalance between water availability and water demand tends to intensify considering the water impact of domestic trade of industrial products. Steps taken to improve water use efficiency in production, and to enhance embodied water saving in consumption are both of great significance for supporting China's water policies.展开更多
China is the largest CH4 emitter in the world. Given the importance of CH4 in greenhouse gas emission inventories, the characteristics ofChina's CH4 emissions at different scales deserve to be fully understood. Prese...China is the largest CH4 emitter in the world. Given the importance of CH4 in greenhouse gas emission inventories, the characteristics ofChina's CH4 emissions at different scales deserve to be fully understood. Presented in this paper is an interprovincial input output embodi- ment analysis of China's regional CH4 emissions in 2007, based on the most recently available multi-regional input- output table, and relevant CH4 emissions data. The results show that the eastern, central and western areas contribute to 48.2%, 28.6%, and 23.3% of the national total embodied emissions, respectively. Guangdong has the highest level of embodied CH4 emissions among all of the 30 regions. The Agriculture sector produces the most embodied CH4 emissions in final demand, followed by the Construction, Food Production and Tobacco Processing, and Other Service Activities sectors. Significant net transfers of embodied CH4 emission flows are identified from the central and western areas to the eastern area via interregional trade. Shanxi is the largest interregional exporter of embodied CH4 emissions. In contrast, Guangdong is the largest interregional importer. Energy activities, agricultural activities, and waste management comprise 65.6%, 30.7%, and 3.7% of the total embodied CH4 emissions in interregional trade, respectively. By using consumption-based accounting principles, the emis- sion magnitudes, per capita emissions, and emission intensities of most eastern regions increase remarkably, while those of some central and western regions decrease largely. To achieve regional CH4 emission mitigation, comprehensive mitigation measures should be designed under consideration of regional transfer of emission responsibility.展开更多
This study combines multi-regional inputoutput(MRIO)model with linear programming(LP)model to explore economic structure adjustment strategies for the reduction of carbon dioxide(CO_(2))emissions.A particular feature ...This study combines multi-regional inputoutput(MRIO)model with linear programming(LP)model to explore economic structure adjustment strategies for the reduction of carbon dioxide(CO_(2))emissions.A particular feature of this study is the identification of the optimal regulation sequence of final products in various regions to reduce CO_(2)emissions with the minimum loss in gross domestic product(GDP).By using China's MRIO tables 2017 with 28 regions and 42 economic sectors,results show that reduction in final demand leads to simultaneous reductions in GDP and CO_(2)emissions.Nevertheless,certain demand side regulation strategy can be adopted to lower CO_(2)emissions at the smallest loss of economic growth.Several key final products,such as metallurgy,nonmetal,metal,and chemical products,should first be regulated to reduce CO_(2)emissions at the minimum loss in GDP.Most of these key products concentrate in the coastal developed regions in China.The proposed MRIO-LP model considers the inter-relationship among various sectors and regions,and can aid policy makers in designing effective policy for industrial structure adjustment at the regional level to achieve the national environmental and economic targets.展开更多
A new SOI power device with multi-region high-concentration fixed charge(MHFC) is reported. The MHFC is formed through implanting Cs or I ion into the buried oxide layer(BOX), by which the high-concentration dynam...A new SOI power device with multi-region high-concentration fixed charge(MHFC) is reported. The MHFC is formed through implanting Cs or I ion into the buried oxide layer(BOX), by which the high-concentration dynamic electrons and holes are induced at the top and bottom interfaces of BOX. The inversion holes can enhance the vertical electric field and raise the breakdown voltage since the drain bias is mainly generated from the BOX. A model of breakdown voltage is developed, from which the optimal spacing has also been obtained. The numerical results indicate that the breakdown voltage of device proposed is increased by 287% in comparison to that of conventional LDMOS.展开更多
First,we devise in this paper,a multi-regions discrete-time model which describes the spatial-temporal spread of an epidemic which starts from one region and enters to regions which are connected with their neighbors ...First,we devise in this paper,a multi-regions discrete-time model which describes the spatial-temporal spread of an epidemic which starts from one region and enters to regions which are connected with their neighbors by any kind of anthropological movement.We suppose homogeneous Susceptible-Infected-Removed(SIR)populations,and we consider in our simulations,a grid of colored cells,which represents the whole domain affected by the epidemic while each cell can represent a sub-domain or region.Second,in order to minimize the number of infected individuals in one region,we propose an optimal control approach based on a travel-blocking vicinity strategy which aims to control only one cell by restricting movements of infected people coming from all neighboring cells.Thus,we show the influence of the optimal control approach on the controlled cell.We should also note that the cellular modeling approach we propose here,can also describes infection dynamics of regions which are not necessarily attached one to an other,even if no empty space can be viewed between cells.The theoretical method we follow for the characterization of the travel-locking optimal controls,is based on a discrete version of Pontryagin's maximum principle while the numerical approach applied to the multi-points boundary value problems we obtain here,is based on discrete progressive-regressive iterative schemes.We illustrate our modeling and control approaches by giving an example of 100 regions.展开更多
A low-Earth-orbit(LEO)satellite network can provide full-coverage access services worldwide and is an essential candidate for future 6G networking.However,the large variability of the geographic distribution of the Ea...A low-Earth-orbit(LEO)satellite network can provide full-coverage access services worldwide and is an essential candidate for future 6G networking.However,the large variability of the geographic distribution of the Earth’s population leads to an uneven service volume distribution of access service.Moreover,the limitations on the resources of satellites are far from being able to serve the traffic in hotspot areas.To enhance the forwarding capability of satellite networks,we first assess how hotspot areas under different load cases and spatial scales significantly affect the network throughput of an LEO satellite network overall.Then,we propose a multi-region cooperative traffic scheduling algorithm.The algorithm migrates low-grade traffic from hotspot areas to coldspot areas for forwarding,significantly increasing the overall throughput of the satellite network while sacrificing some latency of end-to-end forwarding.This algorithm can utilize all the global satellite resources and improve the utilization of network resources.We model the cooperative multi-region scheduling of large-scale LEO satellites.Based on the model,we build a system testbed using OMNET++to compare the proposed method with existing techniques.The simulations show that our proposed method can reduce the packet loss probability by 30%and improve the resource utilization ratio by 3.69%.展开更多
With the continuous enhancement of regional connectivity,the indirect use of land resources through the pathways of trade in goods and services plays an increasingly important role in the overall utilization of land r...With the continuous enhancement of regional connectivity,the indirect use of land resources through the pathways of trade in goods and services plays an increasingly important role in the overall utilization of land resources.Despite this,relevant research in this field is still in its infancy,and few papers have addressed this issue.This paper uses a multi-regional input–output model to calculate the embodied land in the 30 provinces(autonomous regions and municipalities)and eight regions of China from the perspective of regional trade and further analyzes the spatial pattern of characteristics associated with embodied land flows.The results show that the amount of embodied land occupied by China’s inter-regional trade accounts for 21.39%of the country’s total land,and an average of 38.54%of China’s provincial land demand is met by land exports from other provinces.More than 80%of land consumed by Beijing,Tianjin,and Shanghai is from other provinces.The provinces of Heilongjiang,Inner Mongolia,Xinjiang,and Hebei are the largest net exporters of cultivated land,forest and grazing and aquatic land,fishery land,and built-up land,respectively(the outflows account for 42.26%,27.53%,38.66%,and 35.28%of the corresponding land types in the province);and Guangdong,Shandong,and Zhejiang are the main net importers.The flow of agricultural land(cultivated land,forest land,grazing land,and aquatic land)generally shows a shift from west to east and from north to south.The regions in northeast and northwest China have the largest scale of agricultural land outflows,mainly into East and South China.In addition,8.43%of cultivated land,7.47%of forest land,6.41%of grazing land,6.88%of aquatic land,and 18.35%of built-up land in China are provided for foreign use through international trade.This paper provides feasible ideas and a theoretical basis for solving the contradiction between land use and ecological protection,which could potentially help to achieve sustainable land use in China.展开更多
This study uses a multi-regional input-output model to measure the consumption-based transfer of embodied air pollution across provinces in China.Revised direct exhaust emissions are compared under regional and indust...This study uses a multi-regional input-output model to measure the consumption-based transfer of embodied air pollution across provinces in China.Revised direct exhaust emissions are compared under regional and industrial standards to reveal the static volume distribution and dynamic transfer paths.The results show that China is characterized by a net inflow of atmospheric pollution pressure.The amount of interprovincial transfer exhibits a two-level divergence.The distribution of net outflow areas exhibits a certain degree of dispersion and uniformity,whereas net inflow areas exhibit local agglomeration.The main transfer paths are from east to west and south to north.Eastern coastal areas are the primary source of embodied pollution transfer,whereas northern coastal areas and the middle reaches of the Yellow River account for the primary concentrations of pollution inflows.The proportion of major industry contributions approximately conforms to the Pareto principle;different resource endowments may provide comparative advantages and thus distinct distributions.展开更多
CO2 emissions embodied in trade have an important and far-reaching impact on CO2 emissions reduction obligations. Based on a multi-regional inputoutput analysis, this paper calculates China's provincial CO2 emissions...CO2 emissions embodied in trade have an important and far-reaching impact on CO2 emissions reduction obligations. Based on a multi-regional inputoutput analysis, this paper calculates China's provincial CO2 emissions embodied in trade and analyzes CO2 emissions embodied in trade per unit of value of trade in 30 Chinese provinces. Several climate policy options that potentially reduce the impact of trade on individual provinces are discussed. One finding from this study is that provincial CO2 emissions embodied in trade accounted for approximately 60.02% of China's CO2 emissions in 2007. The CO2 emissions embodied in imports and exports for 30 Chinese provinces differ widely, and remarkable differences in the CO2 emissions embodied in trade per unit of value of trade exist. Another important finding, is that if provinces take binding commitments as a part of a coalition, instead of as individual provinces, then the impacts of trade can be reduced. Notably, however, the extent of reduction in a coalition varies in different provinces.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
Based on a global input-output model, this paper investigates the CO2 emission transfer between China and developed economies through trade. The results show that approximately 15-23 percent of China's production-bas...Based on a global input-output model, this paper investigates the CO2 emission transfer between China and developed economies through trade. The results show that approximately 15-23 percent of China's production-based emissions during 1995-2009 were induced by the production of goods and services satisfying final demand in developed economies. Decomposition of emission transfers shows that trade of intermediate products played a significant role in emission transfer from developed economies to China. Most developed economies have consumption-based emission responsibilities that are higher than their production-based responsibilities, whereas China's consumption-based responsibility is significantly lower than its production-based responsibility. We argue that a fair and efficient carbon accounting approach should take CO 2 emission transfers from developed economies to developing economies into consideration. It is important that China and its developed trade partners cooperate in reducing emission transfers.展开更多
With a Multi-Regional Input-Output model,this study quantifies global final energy demands’grey water footprint(GWF)based on the latest available data.In 2009,9.10 km^3 of freshwater was required to dilute the pollut...With a Multi-Regional Input-Output model,this study quantifies global final energy demands’grey water footprint(GWF)based on the latest available data.In 2009,9.10 km^3 of freshwater was required to dilute the pollutants generated along the life-cycle supply chain of global energy final demands to concentrations permitted by relevant environmental regulations.On a national level,final energy demands in China,USA,India,Japan,and Brazil required the largest GWF of 1.45,1.19,0.79,0.51,and 0.45 km^3 respectively,while European countries have the highest energy demands GWF per capita.From the producer perspective,the largest GWF was generated in BRIC countries,i.e.5 Russia(1.54 km^3),China(1.35 km^3),India(0.92 km^3)and Brazil(0.56 km^3)to support global final energy demands.Because of global trading activities,a country or region’s final energy demands also give rise to water pollutants beyond its territorial boundaries.Cyprus,Greece,Luxembourg,and Malta almost entirely rely on foreign water resources to dilute water pollutants generated to meet their final energy demands.Energy demands in BRIC countries have the least dependency on external water resources.On a global average,56.9%of GWF for energy demands was generated beyond national boundaries.Energy demands in the global north are inducing water pollutions in the global south.展开更多
As the major primary energy importer in the world,China has engaged in considerable efforts to ensure energy security.However,little attention has been paid to China’s embodied primary energy exports.Separating the i...As the major primary energy importer in the world,China has engaged in considerable efforts to ensure energy security.However,little attention has been paid to China’s embodied primary energy exports.Separating the international export from regional final demand,this paper focuses on quantifying provincial primary energy requirement arising from China’s exports,and tracing its concrete interprovincial supply chains using multi-regional input-output analysis and structural path analysis.Results show that China’s embodied primary energy uses in exports(EEE)reached 633.01 Mtce in 2012,compared to 565.15 Mtce in 2007.Four fifths of the EEE were supplied through interprovincial trade.Eastern coastal provinces accounted for nearly 70%of the national total EEE,while their primary energy supply mainly sourced from the central and western provinces.Most interprovincial supply chain paths of embodied primary energy exports were traced to the coal mining sectors of Shanxi,Inner Mongolia and Shaanxi.Critical receiving sectors in the final export provinces were Chemical industry,Metallurgy,Electronic equipment,Textile and other manufacturing sectors.Important transmission sectors were Electricity and hot water production and supply and Petroleum refining,coking,etc.In view of the specific role of exports in primary energy requirements,provincial energy uses are largely dependent on its domestic trade position and degrees of industrial participation in the global economy.Managing critical industrial sectors and supply chain paths associated with the international exports provide new insights to ensure China’s energy security and to formulate targeted energy policies.展开更多
Introduction:The Belt and Road Initiative(BRI)is an important cooperative framework that increasingly affects the global economy,trade,and emission patterns.However,most existing studies pay insufficient attention to ...Introduction:The Belt and Road Initiative(BRI)is an important cooperative framework that increasingly affects the global economy,trade,and emission patterns.However,most existing studies pay insufficient attention to consumption-based emissions,embodied emissions,and non-CO_(2) greenhouse gases(GHGs).This study constructs a GHG emissions database to study the trends and variations in production-based,consumption-based,and embodied emissions associated with BRI countries.Outcome:We find that the per capita GHG emissions of BRI countries are lower than the global average but show significant variation within this group.We also find that trade-embodied emissions between BRI countries and China are growing.As a group,BRI countries are anet exporter of GHGs,with a global share of net export emissions of about 20%.In 2011,nearly 80%of GHG export emissions from BRI countries flowed to non-BRI countries,and nearly 15%flowed to China;about 57%of GHG import emissions were from non-BRI countries,and about 38%were from China.Conclusion:Therefore,this study concludes that the BRI should be used to coordinate climate governance to accelerate and strengthen the dissemination and deployment of low-emissions technologies,strategies,and policies within the BRI so as to avoid a carbon-intensive lock-in effect.展开更多
The construction industry is one of the largest energy consumers in China. It not only uses energy directly but also consumes a large amount of embodied energy hidden in intermediate goods and services from other indu...The construction industry is one of the largest energy consumers in China. It not only uses energy directly but also consumes a large amount of embodied energy hidden in intermediate goods and services from other industries. This paper utilizes the multi-regional input-output(MRIO)model to measure the embodied energy consumption in China's construction industry at the province level. To quantify the backward and forward linkages between the construction industry and other industries, the energy-driven and energy-driving abilities of the construction industry are investigated for 30 provinces. The results show that the values of the energy-driven coefficients are significantly larger than the energy-driving coefficients, indicating that the construction industry is highly dependent on products from other industries and other regions, not vice versa. The construction industries in the southwest and northwest regions of China have the highest energy-driven coefficients, showing that the construction industries in west China heavily rely on indirect energy embodied in goods and services. This particularly applies in Guangxi and Hainan provinces, which have the highest energydriven abilities and the lowest energy-driving abilities. The findings can facilitate the policy-makers to examine the critical energy-saving paths.展开更多
Scientifically assessing the economic impact of major public health emergencies,containing their negative effects,and enhancing the resilience of an economy are important national strategic needs.The new coronavirus d...Scientifically assessing the economic impact of major public health emergencies,containing their negative effects,and enhancing the resilience of an economy are important national strategic needs.The new coronavirus disease(COVID-19)has,to date,been effectively contained in China,but the threat of imported cases and local risks still exist.The systematic identification of the virus’s path of influence and intensity is significant for economic recovery.This study is based on a refined multi-regional general equilibrium analysis model,which measures the economic and industrial impacts at different epidemic risk levels in China and simulates development trends and the degree of damage to industries and the economy under changes to supplies of production materials and product demand.The results show that,at the macroeconomic level,China’s GDP will decline about 0.4%to 0.8%compared to normal in 2020,with an average drop of about 2%in short-term consumption,an average drop in employment of about 0.7%,and an average increase in prices of about 0.9%.At the industry level,the epidemic will have the greatest short-term impact on consumer and laborintensive industries.For example,the output value of the service industry will fall 6.3%compared to normal.Looking at the impact of the epidemic on the industrial system,the province most affected by the epidemic is Hubei,which is the only province in China in the level-1 risk category.As the disease spread outward from Hubei,there were clear differences in the main industries that were impacted in different regions.In addition,simulation results of recovery intensity of regional economies under the two epidemic response scenarios of resumption of work and production and active fiscal stimulus policies show that an increase in fiscal stimulus policies produces a 0.3%higher rate of gross regional product growth but it causes commodity prices to rise by about 1.8%.Measures to resume work and production offer a wider scope for industrial recovery.展开更多
By using a new economic geography model of multi-region to study the impact of market scale on spatial economic structure,we find that the home market effect plays a key role in it.At different development periods,und...By using a new economic geography model of multi-region to study the impact of market scale on spatial economic structure,we find that the home market effect plays a key role in it.At different development periods,under external shocks such as transportation costs and so on,industry shares will change due to the distribution of market scale.The spatial economic structure will gradually evolve into such forms as single core or dual-core structure,especially"central collapse"will be found in the process.Such results can be used to analyze the practical problems,including the"central collapse"in the east,central and west regions of China,the structure of city clusters,etc.With the rapid development of transportation infrastructures,China will form a variety of development patterns on different spatial scales owing to home market effect.The regional convergence can be reached through reducing the economic distance and promoting agglomerative economies,which will help achieve regional coordinated development.展开更多
基金This study has been supported by the National Natural Science Foundation of China (Grant No. 71403270), the Foundation of State Key Laboratory of Coal Resources and Safe Mining, China University of Mining & Technology (Grant No. SKLCRSM14KFA03), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120023120002).
文摘With ever increasing water demands and the continuous intensification of water scarcity arising from China's industrialization, the country is struggling to harmonize its industrial development and water supply. This paper presents a systems analysis of water with- drawals by Chinese industry and investigates demand- driven industrial water uses embodied in final demand and interregional trade based on a multi-regional input-output model. In 2007, the Electric Power, Steam, and Hot Water Production and Supply sector ranks first in direct industrial water withdrawal (DWW), and Construction has the largest embodied industrial water use (EWU). Investment, consumption, and exports contribute to 34.6%, 33.3%, and 30.6% of the national total EWU, respectively. Specifically, 58.0%, 51.1%, 48.6%, 43.3%, and 37.5% of the regional EWUs respectively in Guangdong, Shanghai, Zhejiang, Jiangsu, and Fujian are attributed to international exports. The total interregional import/export of embodied water is equivalent to about 40% of the national total DWW, of which 55.5% is associated with the DWWs of Electric Power, Steam, and Hot Water Production and Supply. Jiangsu is the biggest interregional exporter and deficit receiver of embodied water, in contrast to Guangdong as the biggest interregional importer and surplus receiver. Without implementing effective water- saving measures and adjusting industrial structures, the regional imbalance between water availability and water demand tends to intensify considering the water impact of domestic trade of industrial products. Steps taken to improve water use efficiency in production, and to enhance embodied water saving in consumption are both of great significance for supporting China's water policies.
文摘China is the largest CH4 emitter in the world. Given the importance of CH4 in greenhouse gas emission inventories, the characteristics ofChina's CH4 emissions at different scales deserve to be fully understood. Presented in this paper is an interprovincial input output embodi- ment analysis of China's regional CH4 emissions in 2007, based on the most recently available multi-regional input- output table, and relevant CH4 emissions data. The results show that the eastern, central and western areas contribute to 48.2%, 28.6%, and 23.3% of the national total embodied emissions, respectively. Guangdong has the highest level of embodied CH4 emissions among all of the 30 regions. The Agriculture sector produces the most embodied CH4 emissions in final demand, followed by the Construction, Food Production and Tobacco Processing, and Other Service Activities sectors. Significant net transfers of embodied CH4 emission flows are identified from the central and western areas to the eastern area via interregional trade. Shanxi is the largest interregional exporter of embodied CH4 emissions. In contrast, Guangdong is the largest interregional importer. Energy activities, agricultural activities, and waste management comprise 65.6%, 30.7%, and 3.7% of the total embodied CH4 emissions in interregional trade, respectively. By using consumption-based accounting principles, the emis- sion magnitudes, per capita emissions, and emission intensities of most eastern regions increase remarkably, while those of some central and western regions decrease largely. To achieve regional CH4 emission mitigation, comprehensive mitigation measures should be designed under consideration of regional transfer of emission responsibility.
基金This work is supported by the National Research Foundation,Prime Ministers Office,Singapore under its Campus for Research Excellence and Technological Enterprise(CREATE)programme,and by the Energy and Environmental Sustainability for Megacities(E2S2)Phase II program of the National Research Foundation,Prime Ministers Office,Singapore under its CREATE programme。
文摘This study combines multi-regional inputoutput(MRIO)model with linear programming(LP)model to explore economic structure adjustment strategies for the reduction of carbon dioxide(CO_(2))emissions.A particular feature of this study is the identification of the optimal regulation sequence of final products in various regions to reduce CO_(2)emissions with the minimum loss in gross domestic product(GDP).By using China's MRIO tables 2017 with 28 regions and 42 economic sectors,results show that reduction in final demand leads to simultaneous reductions in GDP and CO_(2)emissions.Nevertheless,certain demand side regulation strategy can be adopted to lower CO_(2)emissions at the smallest loss of economic growth.Several key final products,such as metallurgy,nonmetal,metal,and chemical products,should first be regulated to reduce CO_(2)emissions at the minimum loss in GDP.Most of these key products concentrate in the coastal developed regions in China.The proposed MRIO-LP model considers the inter-relationship among various sectors and regions,and can aid policy makers in designing effective policy for industrial structure adjustment at the regional level to achieve the national environmental and economic targets.
基金supported by the State Key Laboratory of Electronic Thin Films and Integrated Devices of China(Grant No.KFJJ201205)the Department of Education Project of Guangxi Province,China(Grant No.201202ZD041)+1 种基金the Postdoctoral Science Foundation Project of China(Grant Nos.2012M521127 and2013T60566)the National Natural Science Foundation of China(Grant Nos.61361011,61274077,and 61464003)
文摘A new SOI power device with multi-region high-concentration fixed charge(MHFC) is reported. The MHFC is formed through implanting Cs or I ion into the buried oxide layer(BOX), by which the high-concentration dynamic electrons and holes are induced at the top and bottom interfaces of BOX. The inversion holes can enhance the vertical electric field and raise the breakdown voltage since the drain bias is mainly generated from the BOX. A model of breakdown voltage is developed, from which the optimal spacing has also been obtained. The numerical results indicate that the breakdown voltage of device proposed is increased by 287% in comparison to that of conventional LDMOS.
基金This work is supported by the Systems Theory Network(Reseau Theorie des Systemes),and Hassan II Academy of Sciences and Technologies-Morocco.
文摘First,we devise in this paper,a multi-regions discrete-time model which describes the spatial-temporal spread of an epidemic which starts from one region and enters to regions which are connected with their neighbors by any kind of anthropological movement.We suppose homogeneous Susceptible-Infected-Removed(SIR)populations,and we consider in our simulations,a grid of colored cells,which represents the whole domain affected by the epidemic while each cell can represent a sub-domain or region.Second,in order to minimize the number of infected individuals in one region,we propose an optimal control approach based on a travel-blocking vicinity strategy which aims to control only one cell by restricting movements of infected people coming from all neighboring cells.Thus,we show the influence of the optimal control approach on the controlled cell.We should also note that the cellular modeling approach we propose here,can also describes infection dynamics of regions which are not necessarily attached one to an other,even if no empty space can be viewed between cells.The theoretical method we follow for the characterization of the travel-locking optimal controls,is based on a discrete version of Pontryagin's maximum principle while the numerical approach applied to the multi-points boundary value problems we obtain here,is based on discrete progressive-regressive iterative schemes.We illustrate our modeling and control approaches by giving an example of 100 regions.
基金This work was supported by the National Key R&D Program of China(2021YFB2900604).
文摘A low-Earth-orbit(LEO)satellite network can provide full-coverage access services worldwide and is an essential candidate for future 6G networking.However,the large variability of the geographic distribution of the Earth’s population leads to an uneven service volume distribution of access service.Moreover,the limitations on the resources of satellites are far from being able to serve the traffic in hotspot areas.To enhance the forwarding capability of satellite networks,we first assess how hotspot areas under different load cases and spatial scales significantly affect the network throughput of an LEO satellite network overall.Then,we propose a multi-region cooperative traffic scheduling algorithm.The algorithm migrates low-grade traffic from hotspot areas to coldspot areas for forwarding,significantly increasing the overall throughput of the satellite network while sacrificing some latency of end-to-end forwarding.This algorithm can utilize all the global satellite resources and improve the utilization of network resources.We model the cooperative multi-region scheduling of large-scale LEO satellites.Based on the model,we build a system testbed using OMNET++to compare the proposed method with existing techniques.The simulations show that our proposed method can reduce the packet loss probability by 30%and improve the resource utilization ratio by 3.69%.
基金The Humanities and Social Sciences Planning Fund of the Ministry of Education,No.21YJAZH087。
文摘With the continuous enhancement of regional connectivity,the indirect use of land resources through the pathways of trade in goods and services plays an increasingly important role in the overall utilization of land resources.Despite this,relevant research in this field is still in its infancy,and few papers have addressed this issue.This paper uses a multi-regional input–output model to calculate the embodied land in the 30 provinces(autonomous regions and municipalities)and eight regions of China from the perspective of regional trade and further analyzes the spatial pattern of characteristics associated with embodied land flows.The results show that the amount of embodied land occupied by China’s inter-regional trade accounts for 21.39%of the country’s total land,and an average of 38.54%of China’s provincial land demand is met by land exports from other provinces.More than 80%of land consumed by Beijing,Tianjin,and Shanghai is from other provinces.The provinces of Heilongjiang,Inner Mongolia,Xinjiang,and Hebei are the largest net exporters of cultivated land,forest and grazing and aquatic land,fishery land,and built-up land,respectively(the outflows account for 42.26%,27.53%,38.66%,and 35.28%of the corresponding land types in the province);and Guangdong,Shandong,and Zhejiang are the main net importers.The flow of agricultural land(cultivated land,forest land,grazing land,and aquatic land)generally shows a shift from west to east and from north to south.The regions in northeast and northwest China have the largest scale of agricultural land outflows,mainly into East and South China.In addition,8.43%of cultivated land,7.47%of forest land,6.41%of grazing land,6.88%of aquatic land,and 18.35%of built-up land in China are provided for foreign use through international trade.This paper provides feasible ideas and a theoretical basis for solving the contradiction between land use and ecological protection,which could potentially help to achieve sustainable land use in China.
基金supported by the Major Projects of the National Social Science Fund of China(grant no.18ZDA126).
文摘This study uses a multi-regional input-output model to measure the consumption-based transfer of embodied air pollution across provinces in China.Revised direct exhaust emissions are compared under regional and industrial standards to reveal the static volume distribution and dynamic transfer paths.The results show that China is characterized by a net inflow of atmospheric pollution pressure.The amount of interprovincial transfer exhibits a two-level divergence.The distribution of net outflow areas exhibits a certain degree of dispersion and uniformity,whereas net inflow areas exhibit local agglomeration.The main transfer paths are from east to west and south to north.Eastern coastal areas are the primary source of embodied pollution transfer,whereas northern coastal areas and the middle reaches of the Yellow River account for the primary concentrations of pollution inflows.The proportion of major industry contributions approximately conforms to the Pareto principle;different resource endowments may provide comparative advantages and thus distinct distributions.
文摘CO2 emissions embodied in trade have an important and far-reaching impact on CO2 emissions reduction obligations. Based on a multi-regional inputoutput analysis, this paper calculates China's provincial CO2 emissions embodied in trade and analyzes CO2 emissions embodied in trade per unit of value of trade in 30 Chinese provinces. Several climate policy options that potentially reduce the impact of trade on individual provinces are discussed. One finding from this study is that provincial CO2 emissions embodied in trade accounted for approximately 60.02% of China's CO2 emissions in 2007. The CO2 emissions embodied in imports and exports for 30 Chinese provinces differ widely, and remarkable differences in the CO2 emissions embodied in trade per unit of value of trade exist. Another important finding, is that if provinces take binding commitments as a part of a coalition, instead of as individual provinces, then the impacts of trade can be reduced. Notably, however, the extent of reduction in a coalition varies in different provinces.
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This paper is supported by the Major Program of the National Social Science Foundation of China (Grant No. 13&ZD167), the National Natural Science Foundation of China (Grant Nos. 71373218 and 71073131) and the Program of Social Science Foundation of Fujian Province (Grant No. 2014C045).
文摘Based on a global input-output model, this paper investigates the CO2 emission transfer between China and developed economies through trade. The results show that approximately 15-23 percent of China's production-based emissions during 1995-2009 were induced by the production of goods and services satisfying final demand in developed economies. Decomposition of emission transfers shows that trade of intermediate products played a significant role in emission transfer from developed economies to China. Most developed economies have consumption-based emission responsibilities that are higher than their production-based responsibilities, whereas China's consumption-based responsibility is significantly lower than its production-based responsibility. We argue that a fair and efficient carbon accounting approach should take CO 2 emission transfers from developed economies to developing economies into consideration. It is important that China and its developed trade partners cooperate in reducing emission transfers.
文摘With a Multi-Regional Input-Output model,this study quantifies global final energy demands’grey water footprint(GWF)based on the latest available data.In 2009,9.10 km^3 of freshwater was required to dilute the pollutants generated along the life-cycle supply chain of global energy final demands to concentrations permitted by relevant environmental regulations.On a national level,final energy demands in China,USA,India,Japan,and Brazil required the largest GWF of 1.45,1.19,0.79,0.51,and 0.45 km^3 respectively,while European countries have the highest energy demands GWF per capita.From the producer perspective,the largest GWF was generated in BRIC countries,i.e.5 Russia(1.54 km^3),China(1.35 km^3),India(0.92 km^3)and Brazil(0.56 km^3)to support global final energy demands.Because of global trading activities,a country or region’s final energy demands also give rise to water pollutants beyond its territorial boundaries.Cyprus,Greece,Luxembourg,and Malta almost entirely rely on foreign water resources to dilute water pollutants generated to meet their final energy demands.Energy demands in BRIC countries have the least dependency on external water resources.On a global average,56.9%of GWF for energy demands was generated beyond national boundaries.Energy demands in the global north are inducing water pollutions in the global south.
基金This study has been supported by the National Natural Science Foundation of China(Grant Nos.71774161 and 71804194)the Fundamental Research Funds for the Central Universities(Zhongnan University of Economics and Law,No.2722019JCT006).
文摘As the major primary energy importer in the world,China has engaged in considerable efforts to ensure energy security.However,little attention has been paid to China’s embodied primary energy exports.Separating the international export from regional final demand,this paper focuses on quantifying provincial primary energy requirement arising from China’s exports,and tracing its concrete interprovincial supply chains using multi-regional input-output analysis and structural path analysis.Results show that China’s embodied primary energy uses in exports(EEE)reached 633.01 Mtce in 2012,compared to 565.15 Mtce in 2007.Four fifths of the EEE were supplied through interprovincial trade.Eastern coastal provinces accounted for nearly 70%of the national total EEE,while their primary energy supply mainly sourced from the central and western provinces.Most interprovincial supply chain paths of embodied primary energy exports were traced to the coal mining sectors of Shanxi,Inner Mongolia and Shaanxi.Critical receiving sectors in the final export provinces were Chemical industry,Metallurgy,Electronic equipment,Textile and other manufacturing sectors.Important transmission sectors were Electricity and hot water production and supply and Petroleum refining,coking,etc.In view of the specific role of exports in primary energy requirements,provincial energy uses are largely dependent on its domestic trade position and degrees of industrial participation in the global economy.Managing critical industrial sectors and supply chain paths associated with the international exports provide new insights to ensure China’s energy security and to formulate targeted energy policies.
基金This work was supported by the National Key Research and Development Program of China[2018YFA0606503]the National Natural Science Foundation of China[71590243,71673162].
文摘Introduction:The Belt and Road Initiative(BRI)is an important cooperative framework that increasingly affects the global economy,trade,and emission patterns.However,most existing studies pay insufficient attention to consumption-based emissions,embodied emissions,and non-CO_(2) greenhouse gases(GHGs).This study constructs a GHG emissions database to study the trends and variations in production-based,consumption-based,and embodied emissions associated with BRI countries.Outcome:We find that the per capita GHG emissions of BRI countries are lower than the global average but show significant variation within this group.We also find that trade-embodied emissions between BRI countries and China are growing.As a group,BRI countries are anet exporter of GHGs,with a global share of net export emissions of about 20%.In 2011,nearly 80%of GHG export emissions from BRI countries flowed to non-BRI countries,and nearly 15%flowed to China;about 57%of GHG import emissions were from non-BRI countries,and about 38%were from China.Conclusion:Therefore,this study concludes that the BRI should be used to coordinate climate governance to accelerate and strengthen the dissemination and deployment of low-emissions technologies,strategies,and policies within the BRI so as to avoid a carbon-intensive lock-in effect.
基金Supported by General Projects of Talent Introduction Project in 2020 of Dalian University of Technology(DUT20RC(3)061)National Natural Science Foundation of China(71801024)National Key R&D Program of China(2018YFD1100203)。
文摘The construction industry is one of the largest energy consumers in China. It not only uses energy directly but also consumes a large amount of embodied energy hidden in intermediate goods and services from other industries. This paper utilizes the multi-regional input-output(MRIO)model to measure the embodied energy consumption in China's construction industry at the province level. To quantify the backward and forward linkages between the construction industry and other industries, the energy-driven and energy-driving abilities of the construction industry are investigated for 30 provinces. The results show that the values of the energy-driven coefficients are significantly larger than the energy-driving coefficients, indicating that the construction industry is highly dependent on products from other industries and other regions, not vice versa. The construction industries in the southwest and northwest regions of China have the highest energy-driven coefficients, showing that the construction industries in west China heavily rely on indirect energy embodied in goods and services. This particularly applies in Guangxi and Hainan provinces, which have the highest energydriven abilities and the lowest energy-driving abilities. The findings can facilitate the policy-makers to examine the critical energy-saving paths.
基金National Natural Science Foundation of China,No.72042020。
文摘Scientifically assessing the economic impact of major public health emergencies,containing their negative effects,and enhancing the resilience of an economy are important national strategic needs.The new coronavirus disease(COVID-19)has,to date,been effectively contained in China,but the threat of imported cases and local risks still exist.The systematic identification of the virus’s path of influence and intensity is significant for economic recovery.This study is based on a refined multi-regional general equilibrium analysis model,which measures the economic and industrial impacts at different epidemic risk levels in China and simulates development trends and the degree of damage to industries and the economy under changes to supplies of production materials and product demand.The results show that,at the macroeconomic level,China’s GDP will decline about 0.4%to 0.8%compared to normal in 2020,with an average drop of about 2%in short-term consumption,an average drop in employment of about 0.7%,and an average increase in prices of about 0.9%.At the industry level,the epidemic will have the greatest short-term impact on consumer and laborintensive industries.For example,the output value of the service industry will fall 6.3%compared to normal.Looking at the impact of the epidemic on the industrial system,the province most affected by the epidemic is Hubei,which is the only province in China in the level-1 risk category.As the disease spread outward from Hubei,there were clear differences in the main industries that were impacted in different regions.In addition,simulation results of recovery intensity of regional economies under the two epidemic response scenarios of resumption of work and production and active fiscal stimulus policies show that an increase in fiscal stimulus policies produces a 0.3%higher rate of gross regional product growth but it causes commodity prices to rise by about 1.8%.Measures to resume work and production offer a wider scope for industrial recovery.
文摘By using a new economic geography model of multi-region to study the impact of market scale on spatial economic structure,we find that the home market effect plays a key role in it.At different development periods,under external shocks such as transportation costs and so on,industry shares will change due to the distribution of market scale.The spatial economic structure will gradually evolve into such forms as single core or dual-core structure,especially"central collapse"will be found in the process.Such results can be used to analyze the practical problems,including the"central collapse"in the east,central and west regions of China,the structure of city clusters,etc.With the rapid development of transportation infrastructures,China will form a variety of development patterns on different spatial scales owing to home market effect.The regional convergence can be reached through reducing the economic distance and promoting agglomerative economies,which will help achieve regional coordinated development.