SHANXI MATUREVINEGAR Vinegar is an indispensable condimentin people’s daily life.In cooking,add somevinegar to the vegetables to protect the vitaminsin them from being spoiled,and vinegar canbe used in cooking fish a...SHANXI MATUREVINEGAR Vinegar is an indispensable condimentin people’s daily life.In cooking,add somevinegar to the vegetables to protect the vitaminsin them from being spoiled,and vinegar canbe used in cooking fish and meat to展开更多
This study presents the development of high strength concrete (HSC) that has been made more sustainable by using both local materials from central Texas and recycled concrete aggregate (RCA), which has also been obtai...This study presents the development of high strength concrete (HSC) that has been made more sustainable by using both local materials from central Texas and recycled concrete aggregate (RCA), which has also been obtained locally. The developed mixtures were proportioned with local constituents to increase the sustainable impact of the material by reducing emissions due to shipping as well as to make HSC more affordable to a wider variety of applications. The specific constituents were: limestone, dolomite, manufactured sand (limestone), locally available Type I/II cement, silica fume, and recycled concrete aggregate, which was obtained from a local recycler which obtains their product from local demolition. Multiple variables were investigated, such as the aggregate type and size, concrete age (7, 14, and 28-days), the curing regimen, and the water-to-cement ratio (w/c) to optimize a HSC mixture that used local materials. This systematic development revealed that heat curing the specimens in a water bath at 50℃ (122oF) after demolding and then dry curing at 200℃ (392oF) two days before testing with a w/c of 0.28 at 28-days produced the highest compressive strengths. Once an optimum HSC mixture was identified a partial replacement of the coarse aggregate with RCA was completed at 10%, 20%, and 30%. The results showed a loss in compressive strength with an increase in RCA replacement percentages, with the highest strength being approximately 93.0 MPa (13,484 psi) at 28-days for the 10% RCA replacement. The lowest strength obtained from an RCA-HSC mixture was approximately 72.9 (MPa) (10,576 psi) at 7-days. The compressive strengths obtained from the HSC mixtures containing RCA developed in this study are comparable to HSC strengths presented in the literature. Developing this innovative material with local materials and RCA ultimately produces a novel sustainable construction material, reduces the costs, and produces mechanical performance similar to prepackaged, commercially, available construction building materials.展开更多
The brand construction of agricultural products is a necessary path for agricultural development and an effective way to enhance the added value and market competitiveness of agricultural products.How to do a good job...The brand construction of agricultural products is a necessary path for agricultural development and an effective way to enhance the added value and market competitiveness of agricultural products.How to do a good job in building agricultural product brands under the background of rural revitalization?This paper takes the honeysuckle industry in Mashan County,Nanning as a case study for comprehensive analysis,forming a driving force for the high-quality development of characteristic agricultural industries.展开更多
The purpose of this paper is to propose and study local spline approximation methods for singular product integration,for which;i)the precision degree is the highest possible using splint approximation; ii) the nodes ...The purpose of this paper is to propose and study local spline approximation methods for singular product integration,for which;i)the precision degree is the highest possible using splint approximation; ii) the nodes fan be assumed equal to arbitrary points,where the integrand function f is known; iii) the number of the requested evaluations of f at the nodes is low,iv) a satisfactory convergence theory can be proved.展开更多
The promotion of rural revitalization within the ecological conservation areas(“ECAs”) requires a careful balance between ecological protection and economic development and should be guided by the principle of ecolo...The promotion of rural revitalization within the ecological conservation areas(“ECAs”) requires a careful balance between ecological protection and economic development and should be guided by the principle of ecological priority. The cultivation of rural “Local Specialty Products”(“LSPs”) under a green-development framework aligns with the functional positioning of these areas, drives the revitalization of rural industries, and constitutes a fundamental strategy for addressing the unique challenges they face. Although ECAs possess inherent advantages in terms of developing LSPs, they are also confronted by multiple constraints. Accordingly, we propose development objectives that emphasize(a) driving rural industrial prosperity,(b) enhancing the appeal of agricultural heritage, and(c) ensuring inclusive prosperity in the farming communities. In selecting pathways for growth, priority should be given to improving the quality of products, fostering distinctiveness of the technologies, nurturing cultural identities, and upholding the principle of common prosperity. From a policy standpoint, the development of rural LSPs should be recognized as a key lever for advancing the comprehensiveness of rural revitalization in the ECAs. We recommend a set of supportive measures—namely, reinforcing the guidance for spatial planning, integrating the consolidation of factor inputs, and ensuring the robustness of organizational guarantees—to facilitate the high-quality development of LSPs in these areas.展开更多
This paper provides a comprehensive reflection on the evolution of globalization research in the Pearl River Delta(PRD),considering the current international context and national strategies.It identifies several chall...This paper provides a comprehensive reflection on the evolution of globalization research in the Pearl River Delta(PRD),considering the current international context and national strategies.It identifies several challenges in existing studies,such as the ambiguity of globalization patterns and the insufficient representativeness of key indicators.In response to these challenges,this paper draws upon the theory of strategic coupling to propose a new theoretical framework for analyzing globalization in latecomer regions.Based on the concepts of spatial stickiness and locational advantages,this paper further develops a two-dimensional quantitative indicator matrix.Using the PRD as a case study,it conducts empirical measurements and analysis,leading to three main conclusions.First,the theory of strategic coupling proves well-suited for analyzing the globalization of latecomer regions,exemplified by the PRD.It offers a more systematic,clearer,and more robust explanatory framework compared to traditional measurement methods.Second,the empirical analysis from the PRD reveals that the pattern of regional globalization does not follow a simple linear growth or cyclical model.Instead,it exhibits a circuitous,complex,and upward spiral,unfolding along an S-shaped evolutionary trajectory.Third,through comparisons of the eastern and western shores,as well as segmented city analyses,this study finds that locational advantages significantly shape the evolutionary pattern of globalization.This influence is not only apparent during the region's initial take-off phase but also plays a more profound role in shaping its subsequent developmental trajectory.This study makes a distinctive contribution to both the theoretical understanding of globalization in latecomer regions and the practical field of regional economic development in China.Additionally,it introduces a novel measurement approach for studying regional globalization.展开更多
With the increasing population in the urban cities of the world,the demand for food from distant areas has been on the rise but at the expense of scarce natural resources like oil,water and forest,etc.However,producin...With the increasing population in the urban cities of the world,the demand for food from distant areas has been on the rise but at the expense of scarce natural resources like oil,water and forest,etc.However,producing food locally in urban centers provides a sustainable mechanism of reducing the carbon,food or ecological footprints of these cities in particular and environmental degradation in general.It creates a circular metabolic system in which the natural inputs are efficiently harnessed rather than the linear metabolic system in which resources flow in and wastes flow out.This article analyzes some urban agricultural local initiatives in urban centers of the worlds that promote a circular metabolic systems and proposes the procedure that can be adopted to promote urban agriculture.展开更多
Objectives:Thermal processes,such as refining and frying,result in the formation of trans fatty acids(TFAs)in edible oils or fats.Concerning the detrimental effect of TFAs on human health,milk fat samples of cow,buffa...Objectives:Thermal processes,such as refining and frying,result in the formation of trans fatty acids(TFAs)in edible oils or fats.Concerning the detrimental effect of TFAs on human health,milk fat samples of cow,buffalo,and goat are collected in order to elucidate TFAs accumulation during thermal processing.Methods:The increased amount of TFAs due to heating is analyzed by attenuated total reflection-Fourier transform infrared(ATR-FTIR)spectroscopy in conjunction with second-derivative treatment and gas chromatographic(GC)analysis.Results:The total amount of TFAs has been increased from 7.71 to 8.25 per cent for cow milk fat,7.12 to 7.82 per cent for buffalo milk fat,and from 6.82 to 7.61 per cent for goat milk fat on heating the samples to 125°C-175°C as predicted by GC.Conclusions:Local food products fried in these milk fats are hence very harmful to human health.These results demonstrate that thermally induced TFAs in milk fats are closely related to the process temperature and time,which should be considered to reduce the formation of TFAs during thermal treatment.展开更多
This paper compares and analyzes the changes in the Chinese automobile market in recent years as well as the competition strategy of top makers of European, American, Japanese, Korean, and Chinese automobiles. In part...This paper compares and analyzes the changes in the Chinese automobile market in recent years as well as the competition strategy of top makers of European, American, Japanese, Korean, and Chinese automobiles. In particular, analysis is carried out on the cause of the rapid growth of European, American, and Korean makers in the passenger vehicle market and the slow growth of Japanese makers, especially, Toyota, Honda, and Chinese makers. In order to adapt to the environmental change in the Chinese automobile market, European and American makers like Volkwagen （VW） and General Motors （GM） have developed full model line-up strategies focusing on compact cars while utilizing the advantages of the annual production of their full model line-up and giving priority to local part procurement. What＇s more, Korea＇s Hyundai has converted its car model strategy from mid-sized cars into compact cars in accordance with the changes in the Chinese market. Through successful product development adjusting to local needs, Hyundai has firmly entrenched its brand name. For Honda and Toyota, the slow conversion from mid-sized cars to compact cars and the inability to decrease costs due to the slow development of local part procurement are the causes of their delayed development in the Chinese market.展开更多
Building the foundations of Thermo-Photo-Electronics became possible only after the correction of thermodynamic errors in the traditional theory of semiconductor Electronics and Photo-Electronics.It is these errors th...Building the foundations of Thermo-Photo-Electronics became possible only after the correction of thermodynamic errors in the traditional theory of semiconductor Electronics and Photo-Electronics.It is these errors that determined the output of the asymptotics of the operating parameters of semiconductor electronic devices,in particular,both the saturation of the limiting clock frequency of processors,and the saturation of the efficiency of both thermoelectric and photoelectric converters.But in semiconductors,although these thermodynamic errors manifested themselves not only in the instrumental,but also in the technological aspect,they could not prohibit semiconductor Electronics itself,unlike Electronics based on other materials.It’s just that a number of qualitative mistakes were made in the theory of semiconductor devices and photo devices.In this work,it is shown that the energy band diagram of semiconductor contacts itself was constructed with a significant omission-without taking into account the temperature force on the contact.At the same time,because of the incorrect calculation of currents according to the outdated formulas of Richardson-Langmuir-Deshman,there were also PROHIBITIONS.So the practitioners compensated for the errors of the theory with“empirical corrections”.So electronics engineers often made devices not according to a strict theory(which simply did not exist until now),but on a hunch and according to empirical local laws.And only the correction of the historical mistakes made it possible to expand the phenomenology of the description of processes in a Solid Body,on the basis of which it is possible to make calculations of highly efficient elements of Photo-Thermo-Electronics.展开更多
In this article,we study the hyperbolic dynamics of geodesic flows on Riemannian(not necessarily compact)manifolds with no conjugate points.By hyperbolic dynamics,we focus on the Anosov Closing Lemma,the local product...In this article,we study the hyperbolic dynamics of geodesic flows on Riemannian(not necessarily compact)manifolds with no conjugate points.By hyperbolic dynamics,we focus on the Anosov Closing Lemma,the local product structure,and the transitivity of the geodesic flows on the set of rank 1 non-wandering setΩ_(1) under the conditions of bounded asymptote and uniform visibility.As an application,we further discuss on some generic properties of the set of invariant probability measures.展开更多
The recent global food security crisis is garnering increasing attention and calls for innovative solutions to mitigate its negative impacts on people, especially the most economically vulnerable. In urban regions, th...The recent global food security crisis is garnering increasing attention and calls for innovative solutions to mitigate its negative impacts on people, especially the most economically vulnerable. In urban regions, this issue is aggravated by the fact that, on one hand, rapid urbanization and greater levels and diversity of food consumption associated with the growing affluence of urban inhabitants has led to rising urban food demand, while on the other hand, the rapid loss of farmland due to urban expansion or irrational sprawl and increasing extreme weather events for agricultural producers due to the impact of global climate change is sharply reducing the urban food production and local supply capacity. Therefore how to realize the urban food supply potential and optimize the utilization of the urban farmlands to enhance the local food supply rate and improve urban food security more generally is becoming a key issue. In this paper, we use the case of Beijing to examine the opportunities to enhance the supply of local, affordably priced food under existing land resource constraints, by restructuring farmland utilization. In this paper, we firstly calculate the changes in the food footprint needed by Beijing and its food self-sufficiency rate over the thirty year period from 1981 to 2011. We show that although Beijing’s food footprint has grown from 11 800 to 29 400 km2 over this 30-year period, its food self- sufficiency rate has dropped from 59.3%, 35.8%, 37.3% and 13.1% to about 39.0%, 27.0%, 6.7% and 2.2% for vegetable, fruit, grain and edible oil, respectively. Following this analysis, we calculate Beijing’ s potential food production under different agricultural production allocation scenarios. We conclude that with a proper shift of farmland use, full utilization of temporary idle land, and the development of rooftop farming, Beijing could increase its vegetable self-sufficiency rate to 60% without significantly reducing the production of other types of local food. Given the sensitivity of fresh vegetables to long- distance transport, and the potential to reduce transport-related carbon emissions, this is a worthwhile adjustment that will benefit the city both by meeting the growing need of its residents for fresh food, and by improving the overall regional eco-environment.展开更多
Abstract In this paper we investigate the quasi-shadowing property for C1 random dynamical sys-terns on their random partially hyperbolic sets. It is shown that for any pseudo orbit {xk}＋∞ -∞ on a random partially ...Abstract In this paper we investigate the quasi-shadowing property for C1 random dynamical sys-terns on their random partially hyperbolic sets. It is shown that for any pseudo orbit {xk}＋∞ -∞ on a random partially hyperbolic set there exists a ＂center＂ pseudo orbit {Yk}＋∞ -∞ shadowing it in the sense that yk＋l is obtained from the image of yk by a motion along the center direction. Moreover, when the random partially hyperbolic set has a local product structure, the above ＂center＂ pseudo orbit{yk}＋∞ -∞ can be chosen such that yk＋1 and the image of yk lie in their common center leaf.展开更多
文摘SHANXI MATUREVINEGAR Vinegar is an indispensable condimentin people’s daily life.In cooking,add somevinegar to the vegetables to protect the vitaminsin them from being spoiled,and vinegar canbe used in cooking fish and meat to
文摘This study presents the development of high strength concrete (HSC) that has been made more sustainable by using both local materials from central Texas and recycled concrete aggregate (RCA), which has also been obtained locally. The developed mixtures were proportioned with local constituents to increase the sustainable impact of the material by reducing emissions due to shipping as well as to make HSC more affordable to a wider variety of applications. The specific constituents were: limestone, dolomite, manufactured sand (limestone), locally available Type I/II cement, silica fume, and recycled concrete aggregate, which was obtained from a local recycler which obtains their product from local demolition. Multiple variables were investigated, such as the aggregate type and size, concrete age (7, 14, and 28-days), the curing regimen, and the water-to-cement ratio (w/c) to optimize a HSC mixture that used local materials. This systematic development revealed that heat curing the specimens in a water bath at 50℃ (122oF) after demolding and then dry curing at 200℃ (392oF) two days before testing with a w/c of 0.28 at 28-days produced the highest compressive strengths. Once an optimum HSC mixture was identified a partial replacement of the coarse aggregate with RCA was completed at 10%, 20%, and 30%. The results showed a loss in compressive strength with an increase in RCA replacement percentages, with the highest strength being approximately 93.0 MPa (13,484 psi) at 28-days for the 10% RCA replacement. The lowest strength obtained from an RCA-HSC mixture was approximately 72.9 (MPa) (10,576 psi) at 7-days. The compressive strengths obtained from the HSC mixtures containing RCA developed in this study are comparable to HSC strengths presented in the literature. Developing this innovative material with local materials and RCA ultimately produces a novel sustainable construction material, reduces the costs, and produces mechanical performance similar to prepackaged, commercially, available construction building materials.
文摘The brand construction of agricultural products is a necessary path for agricultural development and an effective way to enhance the added value and market competitiveness of agricultural products.How to do a good job in building agricultural product brands under the background of rural revitalization?This paper takes the honeysuckle industry in Mashan County,Nanning as a case study for comprehensive analysis,forming a driving force for the high-quality development of characteristic agricultural industries.
基金Work sponsored by"Ministero dell' University"CNR of Italy
文摘The purpose of this paper is to propose and study local spline approximation methods for singular product integration,for which;i)the precision degree is the highest possible using splint approximation; ii) the nodes fan be assumed equal to arbitrary points,where the integrand function f is known; iii) the number of the requested evaluations of f at the nodes is low,iv) a satisfactory convergence theory can be proved.
基金a phased research outcome report of the Major Innovation Project of the Chinese Academy of Social Sciences,“Research on Major Issues in Improving the Mechanisms and Institutions for Integrated Urban-Rural Development”(Project No. 2024YZD008)。
文摘The promotion of rural revitalization within the ecological conservation areas(“ECAs”) requires a careful balance between ecological protection and economic development and should be guided by the principle of ecological priority. The cultivation of rural “Local Specialty Products”(“LSPs”) under a green-development framework aligns with the functional positioning of these areas, drives the revitalization of rural industries, and constitutes a fundamental strategy for addressing the unique challenges they face. Although ECAs possess inherent advantages in terms of developing LSPs, they are also confronted by multiple constraints. Accordingly, we propose development objectives that emphasize(a) driving rural industrial prosperity,(b) enhancing the appeal of agricultural heritage, and(c) ensuring inclusive prosperity in the farming communities. In selecting pathways for growth, priority should be given to improving the quality of products, fostering distinctiveness of the technologies, nurturing cultural identities, and upholding the principle of common prosperity. From a policy standpoint, the development of rural LSPs should be recognized as a key lever for advancing the comprehensiveness of rural revitalization in the ECAs. We recommend a set of supportive measures—namely, reinforcing the guidance for spatial planning, integrating the consolidation of factor inputs, and ensuring the robustness of organizational guarantees—to facilitate the high-quality development of LSPs in these areas.
基金National Natural Science Foundation of China,No.42271182,No.42122006,No.42101171。
文摘This paper provides a comprehensive reflection on the evolution of globalization research in the Pearl River Delta(PRD),considering the current international context and national strategies.It identifies several challenges in existing studies,such as the ambiguity of globalization patterns and the insufficient representativeness of key indicators.In response to these challenges,this paper draws upon the theory of strategic coupling to propose a new theoretical framework for analyzing globalization in latecomer regions.Based on the concepts of spatial stickiness and locational advantages,this paper further develops a two-dimensional quantitative indicator matrix.Using the PRD as a case study,it conducts empirical measurements and analysis,leading to three main conclusions.First,the theory of strategic coupling proves well-suited for analyzing the globalization of latecomer regions,exemplified by the PRD.It offers a more systematic,clearer,and more robust explanatory framework compared to traditional measurement methods.Second,the empirical analysis from the PRD reveals that the pattern of regional globalization does not follow a simple linear growth or cyclical model.Instead,it exhibits a circuitous,complex,and upward spiral,unfolding along an S-shaped evolutionary trajectory.Third,through comparisons of the eastern and western shores,as well as segmented city analyses,this study finds that locational advantages significantly shape the evolutionary pattern of globalization.This influence is not only apparent during the region's initial take-off phase but also plays a more profound role in shaping its subsequent developmental trajectory.This study makes a distinctive contribution to both the theoretical understanding of globalization in latecomer regions and the practical field of regional economic development in China.Additionally,it introduces a novel measurement approach for studying regional globalization.
文摘With the increasing population in the urban cities of the world,the demand for food from distant areas has been on the rise but at the expense of scarce natural resources like oil,water and forest,etc.However,producing food locally in urban centers provides a sustainable mechanism of reducing the carbon,food or ecological footprints of these cities in particular and environmental degradation in general.It creates a circular metabolic system in which the natural inputs are efficiently harnessed rather than the linear metabolic system in which resources flow in and wastes flow out.This article analyzes some urban agricultural local initiatives in urban centers of the worlds that promote a circular metabolic systems and proposes the procedure that can be adopted to promote urban agriculture.
文摘Objectives:Thermal processes,such as refining and frying,result in the formation of trans fatty acids(TFAs)in edible oils or fats.Concerning the detrimental effect of TFAs on human health,milk fat samples of cow,buffalo,and goat are collected in order to elucidate TFAs accumulation during thermal processing.Methods:The increased amount of TFAs due to heating is analyzed by attenuated total reflection-Fourier transform infrared(ATR-FTIR)spectroscopy in conjunction with second-derivative treatment and gas chromatographic(GC)analysis.Results:The total amount of TFAs has been increased from 7.71 to 8.25 per cent for cow milk fat,7.12 to 7.82 per cent for buffalo milk fat,and from 6.82 to 7.61 per cent for goat milk fat on heating the samples to 125°C-175°C as predicted by GC.Conclusions:Local food products fried in these milk fats are hence very harmful to human health.These results demonstrate that thermally induced TFAs in milk fats are closely related to the process temperature and time,which should be considered to reduce the formation of TFAs during thermal treatment.
文摘This paper compares and analyzes the changes in the Chinese automobile market in recent years as well as the competition strategy of top makers of European, American, Japanese, Korean, and Chinese automobiles. In particular, analysis is carried out on the cause of the rapid growth of European, American, and Korean makers in the passenger vehicle market and the slow growth of Japanese makers, especially, Toyota, Honda, and Chinese makers. In order to adapt to the environmental change in the Chinese automobile market, European and American makers like Volkwagen （VW） and General Motors （GM） have developed full model line-up strategies focusing on compact cars while utilizing the advantages of the annual production of their full model line-up and giving priority to local part procurement. What＇s more, Korea＇s Hyundai has converted its car model strategy from mid-sized cars into compact cars in accordance with the changes in the Chinese market. Through successful product development adjusting to local needs, Hyundai has firmly entrenched its brand name. For Honda and Toyota, the slow conversion from mid-sized cars to compact cars and the inability to decrease costs due to the slow development of local part procurement are the causes of their delayed development in the Chinese market.
文摘Building the foundations of Thermo-Photo-Electronics became possible only after the correction of thermodynamic errors in the traditional theory of semiconductor Electronics and Photo-Electronics.It is these errors that determined the output of the asymptotics of the operating parameters of semiconductor electronic devices,in particular,both the saturation of the limiting clock frequency of processors,and the saturation of the efficiency of both thermoelectric and photoelectric converters.But in semiconductors,although these thermodynamic errors manifested themselves not only in the instrumental,but also in the technological aspect,they could not prohibit semiconductor Electronics itself,unlike Electronics based on other materials.It’s just that a number of qualitative mistakes were made in the theory of semiconductor devices and photo devices.In this work,it is shown that the energy band diagram of semiconductor contacts itself was constructed with a significant omission-without taking into account the temperature force on the contact.At the same time,because of the incorrect calculation of currents according to the outdated formulas of Richardson-Langmuir-Deshman,there were also PROHIBITIONS.So the practitioners compensated for the errors of the theory with“empirical corrections”.So electronics engineers often made devices not according to a strict theory(which simply did not exist until now),but on a hunch and according to empirical local laws.And only the correction of the historical mistakes made it possible to expand the phenomenology of the description of processes in a Solid Body,on the basis of which it is possible to make calculations of highly efficient elements of Photo-Thermo-Electronics.
基金supported by Natural Science Foundation of China(NSFC)under(Grant No.12571179)supported by Natural Science Foundation of China(NSFC)under(Grant No.11871045)key research project of the Academy for Multidisciplinary Studies,Capital Normal University。
文摘In this article,we study the hyperbolic dynamics of geodesic flows on Riemannian(not necessarily compact)manifolds with no conjugate points.By hyperbolic dynamics,we focus on the Anosov Closing Lemma,the local product structure,and the transitivity of the geodesic flows on the set of rank 1 non-wandering setΩ_(1) under the conditions of bounded asymptote and uniform visibility.As an application,we further discuss on some generic properties of the set of invariant probability measures.
基金funded by the National Natural Science Foundation of China (40971100)
文摘The recent global food security crisis is garnering increasing attention and calls for innovative solutions to mitigate its negative impacts on people, especially the most economically vulnerable. In urban regions, this issue is aggravated by the fact that, on one hand, rapid urbanization and greater levels and diversity of food consumption associated with the growing affluence of urban inhabitants has led to rising urban food demand, while on the other hand, the rapid loss of farmland due to urban expansion or irrational sprawl and increasing extreme weather events for agricultural producers due to the impact of global climate change is sharply reducing the urban food production and local supply capacity. Therefore how to realize the urban food supply potential and optimize the utilization of the urban farmlands to enhance the local food supply rate and improve urban food security more generally is becoming a key issue. In this paper, we use the case of Beijing to examine the opportunities to enhance the supply of local, affordably priced food under existing land resource constraints, by restructuring farmland utilization. In this paper, we firstly calculate the changes in the food footprint needed by Beijing and its food self-sufficiency rate over the thirty year period from 1981 to 2011. We show that although Beijing’s food footprint has grown from 11 800 to 29 400 km2 over this 30-year period, its food self- sufficiency rate has dropped from 59.3%, 35.8%, 37.3% and 13.1% to about 39.0%, 27.0%, 6.7% and 2.2% for vegetable, fruit, grain and edible oil, respectively. Following this analysis, we calculate Beijing’ s potential food production under different agricultural production allocation scenarios. We conclude that with a proper shift of farmland use, full utilization of temporary idle land, and the development of rooftop farming, Beijing could increase its vegetable self-sufficiency rate to 60% without significantly reducing the production of other types of local food. Given the sensitivity of fresh vegetables to long- distance transport, and the potential to reduce transport-related carbon emissions, this is a worthwhile adjustment that will benefit the city both by meeting the growing need of its residents for fresh food, and by improving the overall regional eco-environment.
基金supported by NSFC(Grant Nos.11371120 and 11771118)supported by Fundamental Research Funds for the Central University,China(Grant No.20720170004)
文摘Abstract In this paper we investigate the quasi-shadowing property for C1 random dynamical sys-terns on their random partially hyperbolic sets. It is shown that for any pseudo orbit {xk}＋∞ -∞ on a random partially hyperbolic set there exists a ＂center＂ pseudo orbit {Yk}＋∞ -∞ shadowing it in the sense that yk＋l is obtained from the image of yk by a motion along the center direction. Moreover, when the random partially hyperbolic set has a local product structure, the above ＂center＂ pseudo orbit{yk}＋∞ -∞ can be chosen such that yk＋1 and the image of yk lie in their common center leaf.
