Ploughing and fertilization practices in rice-wheat system have deteriorated the soil carbon (C) pools. Conservation agriculture (CA) based management approaches have proven to enhance C sequestration and reverse the ...Ploughing and fertilization practices in rice-wheat system have deteriorated the soil carbon (C) pools. Conservation agriculture (CA) based management approaches have proven to enhance C sequestration and reverse the loss of soil-organic-carbon (SOC), which further enhances soil fertility. Different fractions of SOC pools react to the alterations in management practices and indicate changes in SOC dynamics as compared to total C in the soil. Higher SOC levels in soil have been observed in case of reduced/no-till (NT) practices than conventional tillage (CT). However, between CT and zero tillage/NT, total SOC stocks diminished with an increase in soil depth, which demonstrated that the benefits of SOC are more pronounced in the topsoil under NT. Soil aggregation provides physical protection to C associated with different-sized particles, thus, the improvement in soil aggregation through CA is an effective way to mitigate soil C loss. Along with less soil disturbance, residual management, suitable crop rotation, rational application of manures and fertilizers, and integrated nutrient management have been found to be effective in not only improving soil C stock but also enhancing the soil health and productivity. Thus, CA can be considered as a potential method in the build-up of SOC of soil in rice-wheat system.展开更多
Based on the system dynamic model, a full system dynamics estimation method is proposed for a chain shell magazine driven by a permanent magnet synchronous motor(PMSM). An adaptive extended state observer(AESO) is pro...Based on the system dynamic model, a full system dynamics estimation method is proposed for a chain shell magazine driven by a permanent magnet synchronous motor(PMSM). An adaptive extended state observer(AESO) is proposed to estimate the unmeasured states and disturbance, in which the model parameters are adjusted in real time. Theoretical analysis shows that the estimation errors of the disturbances and unmeasured states converge exponentially to zero, and the parameter estimation error can be obtained from the extended state. Then, based on the extended state of the AESO, a novel parameter estimation law is designed. Due to the convergence of AESO, the novel parameter estimation law is insensitive to controllers and excitation signal. Under persistent excitation(PE) condition, the estimated parameters will converge to a compact set around the actual parameter value. Without PE signal, the estimated parameters will converge to zero for the extended state. Simulation and experimental results show that the proposed method can accurately estimate the unmeasured states and disturbance of the chain shell magazine, and the estimated parameters will converge to the actual value without strictly continuous PE signals.展开更多
Smart agriculture modifies traditional farming practices,and offers innovative approaches to boost production and sustainability by leveraging contemporary technologies.In today’s world where technology is everything...Smart agriculture modifies traditional farming practices,and offers innovative approaches to boost production and sustainability by leveraging contemporary technologies.In today’s world where technology is everything,these technologies are utilized to streamline regular tasks and procedures in agriculture,one of the largest and most significant industries in every nation.This research paper stands out from existing literature on smart agriculture security by providing a comprehensive analysis and examination of security issues within smart agriculture systems.Divided into three main sections-security analysis,system architecture and design and risk assessment of Cyber-Physical Systems(CPS)applications-the study delves into various elements crucial for smart farming,such as data sources,infrastructure components,communication protocols,and the roles of different stakeholders such as farmers,agricultural scientists and researchers,technology providers,government agencies,consumers and many others.In contrast to earlier research,this work analyzes the resilience of smart agriculture systems using approaches such as threat modeling,penetration testing,and vulnerability assessments.Important discoveries highlight the concerns connected to unsecured communication protocols,possible threats from malevolent actors,and vulnerabilities in IoT devices.Furthermore,the study suggests enhancements for CPS applications,such as strong access controls,intrusion detection systems,and encryption protocols.In addition,risk assessment techniques are applied to prioritize mitigation tactics and detect potential hazards,addressing issues like data breaches,system outages,and automated farming process sabotage.The research sets itself apart even more by presenting a prototype CPS application that makes use of a digital temperature sensor.This application was first created using a Tinkercad simulator and then using actual hardware with Arduino boards.The CPS application’s defenses against potential threats and vulnerabilities are strengthened by this integrated approach,which distinguishes this research for its depth and usefulness in the field of smart agriculture security.展开更多
Ecological high-value agriculture research, ecological high-value agricultural is the future of agriculture in China. In the emergy diagram was constructed based on emergy theory, and the mechanism and realization ap...Ecological high-value agriculture research, ecological high-value agricultural is the future of agriculture in China. In the emergy diagram was constructed based on emergy theory, and the mechanism and realization approach were well described. In addition, a set of evaluation index system of emergy was established to deter- mine contribution made by different resources of the system, providing references for further exploration of ecological high-value agricultural production system.展开更多
The power grid,as the hub connecting the power supply and consumption sides,plays an important role in achieving carbon neutrality in China.In emerging carbon markets,assessing the investment benefits of power-grid en...The power grid,as the hub connecting the power supply and consumption sides,plays an important role in achieving carbon neutrality in China.In emerging carbon markets,assessing the investment benefits of power-grid enterprises is essential.Thus,studying the impact of the carbon market on the investment and operation of powergrid enterprises is key to ensuring their efficient operation.Notably,few studies have examined the interaction between the carbon and electricity markets using system dynamics models,highlighting a research gap in this area.This study investigates the impact of the carbon market on the investment of power-grid enterprises using a novel evaluation system based on a system dynamics model that considers carbon-emissions from an established carbon-emission accounting model.First,an index system for benefit evaluation was constructed from six aspects:financing ability,economic benefit,reliability,social responsibility,user satisfaction,and carbon-emissions.A system dynamics model was then developed to reflect the causal feedback relationship between the impact of the carbon market on the investment and operation of power-grid enterprises.The simulation results of a provincial power-grid enterprise analyze comprehensive investment evaluation benefits over a 10-year period and the impact of carbon emissions on the investment and operation of power-grid enterprises.This study provides guidelines for the benign development of power-grid enterprises within the context of the carbon market.展开更多
Through analyzing syntactic,semantic,pragmatic information,the retrieval system ACIS based on comprehensive information was established,which could achieve personalized information exaction to guide user s information...Through analyzing syntactic,semantic,pragmatic information,the retrieval system ACIS based on comprehensive information was established,which could achieve personalized information exaction to guide user s information retrieval.展开更多
[Objetive] To make clear the regional agricultural development level.[Method] To accelerate the process of modern agricultural development of Bohai Rim,the assessment index system of modern agriculture was established...[Objetive] To make clear the regional agricultural development level.[Method] To accelerate the process of modern agricultural development of Bohai Rim,the assessment index system of modern agriculture was established preliminarily and the data of provinces and cities in Bohai Rim was evaluated and analyzed,regarding the comprehensive development level of modern agriculture as general target and the input level of modern agriculture,the output level of modern agriculture,the social development level of countryside and the sustainable development level of agriculture as grading index.[Result] The results showed that Bohai Rim just entered the developmental stage of modern agriculture,with the integrated index of 0.585.Viewed from regional perspective,Beijing topped the others with the index of 0.798,which was followed by 0.694 of Tianjin,0.644 of Shandong,0.606 of Liaoning and Hebei province had the lowest value of 0.595.[Conclusion] Among all cities in this region,none of them reached at the developed level of modern agriculture.There were ten cities,which were mainly located in Shandong Province,were at the primary stage while the most of others were at the preliminary or initial stage.展开更多
With precision agriculture as the base line, using embedded system as technical support, a set of ideas is proposed for solving the serious pesticide poisoning problem, including farmland information collection, exper...With precision agriculture as the base line, using embedded system as technical support, a set of ideas is proposed for solving the serious pesticide poisoning problem, including farmland information collection, experts database analysis and variable pesticide spraying, etc.展开更多
Rural complex is a bright spot for China to realize the development of new industries for rural revitalization.Starting from the concept,development history and current situation of rural complex,based on the perspect...Rural complex is a bright spot for China to realize the development of new industries for rural revitalization.Starting from the concept,development history and current situation of rural complex,based on the perspective of production-living-ecological space,according to the different characteristics of agriculture and tourism,3 secondary indices and 18 tertiary indices were selected,and each of them was weighted using the Delphi expert consultation method and analytic hierarchy process(AHP)to construct an evaluation system for the coupling degree of agriculture and tourism in rural complex.The results show gross domestic product and forest coverage have the most significant impact on agriculture,economic benefits and the ecological water quality of tourist attractions have the most significant impact on the tourism industry,and tourism economic benefits and agricultural ecological benefits have the most significant impact on rural complex.展开更多
Based on CNKI core journals and CSSCI database, "agriculture, rural areas and farmers" were used as the key words to summarize 20 core articles and CSSCI articles with "agriculture, rural areas and farm...Based on CNKI core journals and CSSCI database, "agriculture, rural areas and farmers" were used as the key words to summarize 20 core articles and CSSCI articles with "agriculture, rural areas and farmers" as the key words from 2015 to 2020, so as to let more researchers have a deeper understanding and grasp of China s current problems of "agriculture, rural areas and farmers". Through the method of comparative analysis of studies, the problems that need to be solved in the work of "agriculture, rural areas and farmers" were discussed, so that other scholars can further clarify the research results and experience of "agriculture, rural areas and farmers", so as to deepen the reform of rural land system and steadily promote the work of "agriculture, rural areas and farmers" in the future. This study can provide thinking and reference for deepening the reform of rural land system and steadily promoting the work of "agriculture, rural areas and farmers".展开更多
Community-supported agriculture(CSA)has emerged as a viable solution for addressing the agricultural challenges faced by countries like Indonesia.This study uses the wellestablished unified theory of acceptance and us...Community-supported agriculture(CSA)has emerged as a viable solution for addressing the agricultural challenges faced by countries like Indonesia.This study uses the wellestablished unified theory of acceptance and use of technology(UTAUT2)model to examine the interest in CSA of potential customers in Indonesia.A standardized questionnaire was distributed to 1200 respondents,and the data were analyzed using structural equation model-partial least square(SEM-PLS)in SmartPLS 4.0 software.The results capture potential CSA consumer interest and will help to improve CSA development strategies in Indonesia.The model explains 44.4%of customers’intentions,and identifies performance expectancy as the decisive factor in customers’willingness to participate in CSA.Performance expectancy(0.292),hedonic motivation(0.262),social influence(0.259),and facilitating conditions(0.086)positively influence customers’interest in participating in a CSA program.The adoption of CSA programs by both farmers and customers could be increased by implementing regulations that provide tax incentives and subsidies,offering training on sustainable farming practices,facilitating the establishment of distribution channels,and establishing guidelines for fair price and quality standards.This study shows the high potential for the implementation of CSA in Indonesia.It could also be used as a foundation for the development of new policies regarding sustainable agriculture markets in Indonesia.展开更多
Based on dynamic theory of system, agriculture is a complex system composed by element, structure, function and development. Firstly, this paper analyzes their connotation and relationship, which could be simply descr...Based on dynamic theory of system, agriculture is a complex system composed by element, structure, function and development. Firstly, this paper analyzes their connotation and relationship, which could be simply described that in virtue of element integrating and structure optimizing, agricultural system may achieve multifunctionality to meet increasingly diverse demands. As a case study of Suzhou, it concludes that Suzhou has a LP-dependence on agricultural element, and the growth extent of agricultural productivity correlates to the ratio of agricultural labor reduc- ing rate to farmland reducing rate. Agricultural structure of Suzhou changed with time, and in the early 1980s and 2000s it was most notable. Correspondingly, agricultural function has experienced a succession process: 'production', 'production-living', and 'production-living-ecology'. At last, based on questionnaires and interviews, some new characteristics and problems of agricultural development in coastal developed region of China have been put forward. Meanwhile, some typical patterns of modern agriculture in Suzhou which adapt to system evolving are also brought up such as export-oriented agriculture, enterprises-leading agriculture, agricultural science and technology parks, characteristic and stereoscopic agriculture, tourism and sightseeing agriculture.展开更多
Urban agriculture is gaining recognition for its potential contributions to environmental resilience and climate change adaptation,providing advantages such as urban greening,reduced heat island effects,and decreased ...Urban agriculture is gaining recognition for its potential contributions to environmental resilience and climate change adaptation,providing advantages such as urban greening,reduced heat island effects,and decreased air pollution.Moreover,it indirectly supports communities during weather events and natural disasters,ensuring food security and fostering community cohesion.However,concerns about planetary health risks persist in highly urbanized and climate-affected areas.Employing electronic databases such as Web of Science and PubMed and adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,we identified 55 relevant papers to comprehend the planetary health risks associated with urban agriculture,The literature review identified five distinct health risks related to urban agriculture:(1)trace metal risks in urban farms;(2)health risks associated with wastewater irrigation;(3)zoonotic risks;(4)other health risks;and(5)social and economic risks.The study highlights that urban agriculture,while emphasizing environmental benefits,particularly raises concerns about trace metal bioaccumulation in soil and vegetables,posing health risks for populations.Other well studied risks included wastewater irrigation and backyard livestock farming.The main limitations in the available literature were in studying infectious diseases and antibiotic resistance associated with urban agriculture.展开更多
Current approaches for sustainable mountain development have several persisting warning signals. Economic globalization, profitoriented market development, and infrastructure development have significantly altered tra...Current approaches for sustainable mountain development have several persisting warning signals. Economic globalization, profitoriented market development, and infrastructure development have significantly altered traditional nature-society interactions, increased environmental pressures, and challenged agricultural sustainability in the mountains. Some of the effects of globalization could also be beneficial. Social differentiation and disintegration of mountain communities' have weakened their collective stakes on natural resources resulting in decline in initiatives such as community forestry, collective water management, domestication of rapidly disappearing herbal species, and balancing of economic and ecological concerns. Population growth, food insecurity, unemployment, and increasing economic gaps between rich and poor have led to out-migration of youth. Sustained action promoting ownership of new initiatives for rehabilitating degraded mountain landscapes through macro-level global/national initiatives, mountain specific planning and development efforts is severely lacking in many areas on the Hindu Kush Himalayan region. Therefore, there is an urgent need for widening the scope of efforts directed to help mountain areas and communities, and a future thinking approach to enhance the sustainability of mountain areas as they are a valuable natural resource for humankind. This paper discusses the issues, opportunities, and provides suggestions for the future of mountain development.展开更多
Achieving sustainability of the cereal system in the Indo-Gangetic Plains(IGP)of India under progressive climate change and variability necessitates adoption of practices and technologies that increase food producti...Achieving sustainability of the cereal system in the Indo-Gangetic Plains(IGP)of India under progressive climate change and variability necessitates adoption of practices and technologies that increase food production,adaptation and mitigation in a sustainable way.This paper examines conservation agriculture(CA)from the perspective of:(i)increased yield and farm income,(ii)adaptation to heat and water stresses,and(iii)reduction in greenhouse gas(GHGs)emissions.The analyses and conclusions are based on the literature and evidences from a large number of on-station as well as farmers’field trials on CA in the cereal systems of IGP.Our analyses show that CA-based system substantially reduces the production cost(up to 23%)but produces equal or even higher than conventional system;thereby increasing economic profitability of production system.CA-based production systems also moderated the effect of high temperature(reduced canopy temperature by 1–4°C)and increased irrigation water productivity by 66–100%compared to traditional production systems thus well adapting to water and heat stress situations of IGP.Our continuous monitoring of soil flux of CO2,N2O and CH4 revealed that CA-based rice-wheat systems emit 10–15%less GHGs than conventional systems.This is the first time that CA and its components are synthesized and analyzed from food security-climate change nexus.From this holistic analysis,we suggest that wide-scale promotion of suitable CA practices by integrating into national agriculture development strategy is a way forward to address food security,climate change adaptation and mitigation challenges faced by present agriculture.展开更多
On the basis of expounding the research results of using relevant knowledge about Game Theory for supply chain of agricultural products at home and abroad,we use principal-agent model in Game Theory to research the ne...On the basis of expounding the research results of using relevant knowledge about Game Theory for supply chain of agricultural products at home and abroad,we use principal-agent model in Game Theory to research the new function that the supermarkets entrust supervision and control over quality of agricultural products to agricultural brokers in the circulation model of connecting agriculture with supermarkets;then design the optimal incentive contract and influencing factors between agricultural broker and supermarket,and explain the fundamental role of agricultural brokers in the process of circulation;finally in light of the role of government in promoting development and application of agricultural brokers,put forward corresponding policy suggestions:establish government support policy;set relevant standard of industry;establish cooperative organizations of agricultural brokers.展开更多
The theory of multibody system dynamics is used to simulate valve trains' kinematics and dynamics characteristics, and the methods of establishing and analyzing the multibody system dynamics model for valve trains...The theory of multibody system dynamics is used to simulate valve trains' kinematics and dynamics characteristics, and the methods of establishing and analyzing the multibody system dynamics model for valve trains are discussed. Since most of the flexible bodies of a valve train are slender parts, the finite segment method is used to build their models. Other parts such as cams, valve heads etc., are built as rigid bodies. After applying the constraints, forces and motions, the establishing of the whole system is accomplished, and the Lagrange's multiplier method can be used to obtain its dynamics constitutive equations. As an example, a valve trains multibody system model of 4100QB engine made by the Yunnan Internal Combustion Engine Limited Liability Company is established, and the analysis results obtained show that its working performance is generally good except that the air pass ability and the lubrication effect of the cam and the tappet have to be improved.展开更多
The paper deals with a transformation model of a backward distric into a prosperous one. The district is geographically located in Lixiahe region, Jiangsu Province. The region had long ben known as one of the poorest ...The paper deals with a transformation model of a backward distric into a prosperous one. The district is geographically located in Lixiahe region, Jiangsu Province. The region had long ben known as one of the poorest area in China, and had been alternatively attacked by flood, waterlogging, drought, salinzation, and plague of insect. Since the seventies of this centruy efforts to open up trenches on lowland and to level up the shoaly land have been made. A kind of tree, which is tolerable to high watertable, was used to afforest the land. Cereal crop, vegetable and beaus are grown. In some cases, the shoaly land is used for sheep grazing and fishery. A favorable combination of forestry, agriculture, animal husbandry and fishery has been set up in the region. There are five type of managements in the system: 1) forestry-agriculture comPlex management. 2) forestry-fishery complex management, 3) forestry-aquatic plan-fishery complex management, 4) forestry-animal husbandry complex management, and 5) forestry-edible mushroom complex management. The principles and ecological benefits of this system can be identitied: 1) Increase soil fertility by piling mud from marsh land on top soil, and thicken the arable layer. 2) Enhance the utilization rate of sunlight and energy, due to the change of microclimate in field. 3) As a result of multiple layer cultivation and multi-cropping, the production has been greatly increased. 4) Accelerate the cycling of matter and conversion of energy and nutrient of the system. 5) Decrease the consUmption of soil fertility and increase the capability of controlling insect pests. 6) Improve ecological environment by afforestationl. 7) Raise income and provide jobs for local peasants, even some ones from other part of this province.展开更多
China is a great agricultural country with large population, limited soilresources and traditional farming mode, so the central government has been attaching greatimportance to the development of agriculture and put f...China is a great agricultural country with large population, limited soilresources and traditional farming mode, so the central government has been attaching greatimportance to the development of agriculture and put forward a new agricultural technologyrevolution ― the transformation from traditional agriculture to modern agriculture and fromextensive farming to intensive farming. Digital agriculture is the core of agriculturalinformatization. The enforcement of digital agriculture will greatly promote agricultural technologyrevolution, two agricultural transformations and its rapid development, and enhance China'scompetitive power after the entrance of WTO. To carry out digital agriculture, the frame system ofdigital agriculture is required to be studied in the first place. In accordance with the theory andtechnology of digital earth and in combination with the agricultural reality of China, this articleoutlines the frame system of digital agriculture and its main content arid technology support.展开更多
Current status of several management models of the agriculture industry is introduced,as well as its impacts on industrial security.The management models are mainly the enterprise-like operation model,"enterprise...Current status of several management models of the agriculture industry is introduced,as well as its impacts on industrial security.The management models are mainly the enterprise-like operation model,"enterprise + peasant household" model,small-scale peasants' operation model,and peasant specialized cooperative model.Functions of peasant specialized cooperative in ensuring the security of agricultural industry are introduced,which are enhancing the industrial security by organization degree,promoting the industrial security by scale economy formed by cooperative organizations,fully utilizing the resources by the factor allocation capability,and ensuring the industrial security by industrial chain improvement.Development predicaments of the peasant specialized cooperative at present are analyzed,such as small scale,poor economic benefits,and non-standard operation.Analysis shows that institutional absence is the main reason causing these predicaments.And suggestions on improving the cooperatives system in the Law of the People's Republic of China on Peasants Specialized Cooperatives are put forward,in order to better ensure the security of agriculture展开更多
文摘Ploughing and fertilization practices in rice-wheat system have deteriorated the soil carbon (C) pools. Conservation agriculture (CA) based management approaches have proven to enhance C sequestration and reverse the loss of soil-organic-carbon (SOC), which further enhances soil fertility. Different fractions of SOC pools react to the alterations in management practices and indicate changes in SOC dynamics as compared to total C in the soil. Higher SOC levels in soil have been observed in case of reduced/no-till (NT) practices than conventional tillage (CT). However, between CT and zero tillage/NT, total SOC stocks diminished with an increase in soil depth, which demonstrated that the benefits of SOC are more pronounced in the topsoil under NT. Soil aggregation provides physical protection to C associated with different-sized particles, thus, the improvement in soil aggregation through CA is an effective way to mitigate soil C loss. Along with less soil disturbance, residual management, suitable crop rotation, rational application of manures and fertilizers, and integrated nutrient management have been found to be effective in not only improving soil C stock but also enhancing the soil health and productivity. Thus, CA can be considered as a potential method in the build-up of SOC of soil in rice-wheat system.
文摘Based on the system dynamic model, a full system dynamics estimation method is proposed for a chain shell magazine driven by a permanent magnet synchronous motor(PMSM). An adaptive extended state observer(AESO) is proposed to estimate the unmeasured states and disturbance, in which the model parameters are adjusted in real time. Theoretical analysis shows that the estimation errors of the disturbances and unmeasured states converge exponentially to zero, and the parameter estimation error can be obtained from the extended state. Then, based on the extended state of the AESO, a novel parameter estimation law is designed. Due to the convergence of AESO, the novel parameter estimation law is insensitive to controllers and excitation signal. Under persistent excitation(PE) condition, the estimated parameters will converge to a compact set around the actual parameter value. Without PE signal, the estimated parameters will converge to zero for the extended state. Simulation and experimental results show that the proposed method can accurately estimate the unmeasured states and disturbance of the chain shell magazine, and the estimated parameters will converge to the actual value without strictly continuous PE signals.
文摘Smart agriculture modifies traditional farming practices,and offers innovative approaches to boost production and sustainability by leveraging contemporary technologies.In today’s world where technology is everything,these technologies are utilized to streamline regular tasks and procedures in agriculture,one of the largest and most significant industries in every nation.This research paper stands out from existing literature on smart agriculture security by providing a comprehensive analysis and examination of security issues within smart agriculture systems.Divided into three main sections-security analysis,system architecture and design and risk assessment of Cyber-Physical Systems(CPS)applications-the study delves into various elements crucial for smart farming,such as data sources,infrastructure components,communication protocols,and the roles of different stakeholders such as farmers,agricultural scientists and researchers,technology providers,government agencies,consumers and many others.In contrast to earlier research,this work analyzes the resilience of smart agriculture systems using approaches such as threat modeling,penetration testing,and vulnerability assessments.Important discoveries highlight the concerns connected to unsecured communication protocols,possible threats from malevolent actors,and vulnerabilities in IoT devices.Furthermore,the study suggests enhancements for CPS applications,such as strong access controls,intrusion detection systems,and encryption protocols.In addition,risk assessment techniques are applied to prioritize mitigation tactics and detect potential hazards,addressing issues like data breaches,system outages,and automated farming process sabotage.The research sets itself apart even more by presenting a prototype CPS application that makes use of a digital temperature sensor.This application was first created using a Tinkercad simulator and then using actual hardware with Arduino boards.The CPS application’s defenses against potential threats and vulnerabilities are strengthened by this integrated approach,which distinguishes this research for its depth and usefulness in the field of smart agriculture security.
基金Supported by the Humanities and Social Sciences of Education Ministry(11YJAZH010)~~
文摘Ecological high-value agriculture research, ecological high-value agricultural is the future of agriculture in China. In the emergy diagram was constructed based on emergy theory, and the mechanism and realization approach were well described. In addition, a set of evaluation index system of emergy was established to deter- mine contribution made by different resources of the system, providing references for further exploration of ecological high-value agricultural production system.
基金supported by the National Natural Science Foundation of China(Grant No.52107087).
文摘The power grid,as the hub connecting the power supply and consumption sides,plays an important role in achieving carbon neutrality in China.In emerging carbon markets,assessing the investment benefits of power-grid enterprises is essential.Thus,studying the impact of the carbon market on the investment and operation of powergrid enterprises is key to ensuring their efficient operation.Notably,few studies have examined the interaction between the carbon and electricity markets using system dynamics models,highlighting a research gap in this area.This study investigates the impact of the carbon market on the investment of power-grid enterprises using a novel evaluation system based on a system dynamics model that considers carbon-emissions from an established carbon-emission accounting model.First,an index system for benefit evaluation was constructed from six aspects:financing ability,economic benefit,reliability,social responsibility,user satisfaction,and carbon-emissions.A system dynamics model was then developed to reflect the causal feedback relationship between the impact of the carbon market on the investment and operation of power-grid enterprises.The simulation results of a provincial power-grid enterprise analyze comprehensive investment evaluation benefits over a 10-year period and the impact of carbon emissions on the investment and operation of power-grid enterprises.This study provides guidelines for the benign development of power-grid enterprises within the context of the carbon market.
基金Supported by the National Natural Science Foundation of China(60575034)Science Foundation of Guangxi Provincial Education Department(200708LX322)~~
文摘Through analyzing syntactic,semantic,pragmatic information,the retrieval system ACIS based on comprehensive information was established,which could achieve personalized information exaction to guide user s information retrieval.
基金Supported by Non-profit project of "Quantitative Evaluation and Adjusting Technology Research on Agricultural Carbon and Nitrogen Balance of Bohai Rim"(200803036)the non-profit project of the twelfth Five-year Plan--"Monitor and Control Research on Agricultural Resource Greenhouse Gas"(201103039)~~
文摘[Objetive] To make clear the regional agricultural development level.[Method] To accelerate the process of modern agricultural development of Bohai Rim,the assessment index system of modern agriculture was established preliminarily and the data of provinces and cities in Bohai Rim was evaluated and analyzed,regarding the comprehensive development level of modern agriculture as general target and the input level of modern agriculture,the output level of modern agriculture,the social development level of countryside and the sustainable development level of agriculture as grading index.[Result] The results showed that Bohai Rim just entered the developmental stage of modern agriculture,with the integrated index of 0.585.Viewed from regional perspective,Beijing topped the others with the index of 0.798,which was followed by 0.694 of Tianjin,0.644 of Shandong,0.606 of Liaoning and Hebei province had the lowest value of 0.595.[Conclusion] Among all cities in this region,none of them reached at the developed level of modern agriculture.There were ten cities,which were mainly located in Shandong Province,were at the primary stage while the most of others were at the preliminary or initial stage.
基金Supported by Education Science " Eleventh Five-Year" Assistance Fund Project in Hebei Province(06130044)Hebei Hengshui City Association of Social Sciences 2009 Social Science Research Projects (0907B)Hengshui University 2009 Class Project(2009016)~~
文摘With precision agriculture as the base line, using embedded system as technical support, a set of ideas is proposed for solving the serious pesticide poisoning problem, including farmland information collection, experts database analysis and variable pesticide spraying, etc.
基金National Undergraduates'Innovation and Entrepreneurship Training Program of China(201910626028).
文摘Rural complex is a bright spot for China to realize the development of new industries for rural revitalization.Starting from the concept,development history and current situation of rural complex,based on the perspective of production-living-ecological space,according to the different characteristics of agriculture and tourism,3 secondary indices and 18 tertiary indices were selected,and each of them was weighted using the Delphi expert consultation method and analytic hierarchy process(AHP)to construct an evaluation system for the coupling degree of agriculture and tourism in rural complex.The results show gross domestic product and forest coverage have the most significant impact on agriculture,economic benefits and the ecological water quality of tourist attractions have the most significant impact on the tourism industry,and tourism economic benefits and agricultural ecological benefits have the most significant impact on rural complex.
文摘Based on CNKI core journals and CSSCI database, "agriculture, rural areas and farmers" were used as the key words to summarize 20 core articles and CSSCI articles with "agriculture, rural areas and farmers" as the key words from 2015 to 2020, so as to let more researchers have a deeper understanding and grasp of China s current problems of "agriculture, rural areas and farmers". Through the method of comparative analysis of studies, the problems that need to be solved in the work of "agriculture, rural areas and farmers" were discussed, so that other scholars can further clarify the research results and experience of "agriculture, rural areas and farmers", so as to deepen the reform of rural land system and steadily promote the work of "agriculture, rural areas and farmers" in the future. This study can provide thinking and reference for deepening the reform of rural land system and steadily promoting the work of "agriculture, rural areas and farmers".
文摘Community-supported agriculture(CSA)has emerged as a viable solution for addressing the agricultural challenges faced by countries like Indonesia.This study uses the wellestablished unified theory of acceptance and use of technology(UTAUT2)model to examine the interest in CSA of potential customers in Indonesia.A standardized questionnaire was distributed to 1200 respondents,and the data were analyzed using structural equation model-partial least square(SEM-PLS)in SmartPLS 4.0 software.The results capture potential CSA consumer interest and will help to improve CSA development strategies in Indonesia.The model explains 44.4%of customers’intentions,and identifies performance expectancy as the decisive factor in customers’willingness to participate in CSA.Performance expectancy(0.292),hedonic motivation(0.262),social influence(0.259),and facilitating conditions(0.086)positively influence customers’interest in participating in a CSA program.The adoption of CSA programs by both farmers and customers could be increased by implementing regulations that provide tax incentives and subsidies,offering training on sustainable farming practices,facilitating the establishment of distribution channels,and establishing guidelines for fair price and quality standards.This study shows the high potential for the implementation of CSA in Indonesia.It could also be used as a foundation for the development of new policies regarding sustainable agriculture markets in Indonesia.
基金Under the auspices of National Natural Science Foundation of China (No. 40635029, No. 40771014)
文摘Based on dynamic theory of system, agriculture is a complex system composed by element, structure, function and development. Firstly, this paper analyzes their connotation and relationship, which could be simply described that in virtue of element integrating and structure optimizing, agricultural system may achieve multifunctionality to meet increasingly diverse demands. As a case study of Suzhou, it concludes that Suzhou has a LP-dependence on agricultural element, and the growth extent of agricultural productivity correlates to the ratio of agricultural labor reduc- ing rate to farmland reducing rate. Agricultural structure of Suzhou changed with time, and in the early 1980s and 2000s it was most notable. Correspondingly, agricultural function has experienced a succession process: 'production', 'production-living', and 'production-living-ecology'. At last, based on questionnaires and interviews, some new characteristics and problems of agricultural development in coastal developed region of China have been put forward. Meanwhile, some typical patterns of modern agriculture in Suzhou which adapt to system evolving are also brought up such as export-oriented agriculture, enterprises-leading agriculture, agricultural science and technology parks, characteristic and stereoscopic agriculture, tourism and sightseeing agriculture.
文摘Urban agriculture is gaining recognition for its potential contributions to environmental resilience and climate change adaptation,providing advantages such as urban greening,reduced heat island effects,and decreased air pollution.Moreover,it indirectly supports communities during weather events and natural disasters,ensuring food security and fostering community cohesion.However,concerns about planetary health risks persist in highly urbanized and climate-affected areas.Employing electronic databases such as Web of Science and PubMed and adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,we identified 55 relevant papers to comprehend the planetary health risks associated with urban agriculture,The literature review identified five distinct health risks related to urban agriculture:(1)trace metal risks in urban farms;(2)health risks associated with wastewater irrigation;(3)zoonotic risks;(4)other health risks;and(5)social and economic risks.The study highlights that urban agriculture,while emphasizing environmental benefits,particularly raises concerns about trace metal bioaccumulation in soil and vegetables,posing health risks for populations.Other well studied risks included wastewater irrigation and backyard livestock farming.The main limitations in the available literature were in studying infectious diseases and antibiotic resistance associated with urban agriculture.
基金supported by the Australian Government through the Sustainable Development Investment Portfoliofunded by the Governments of Norwaycore funds of ICIMOD contributed by the governments of Afghanistan, Australia, Austria, Bangladesh, Bhutan, China, India, Myanmar, Nepal, Norway, Pakistan, Switzerland, and the United Kingdom
文摘Current approaches for sustainable mountain development have several persisting warning signals. Economic globalization, profitoriented market development, and infrastructure development have significantly altered traditional nature-society interactions, increased environmental pressures, and challenged agricultural sustainability in the mountains. Some of the effects of globalization could also be beneficial. Social differentiation and disintegration of mountain communities' have weakened their collective stakes on natural resources resulting in decline in initiatives such as community forestry, collective water management, domestication of rapidly disappearing herbal species, and balancing of economic and ecological concerns. Population growth, food insecurity, unemployment, and increasing economic gaps between rich and poor have led to out-migration of youth. Sustained action promoting ownership of new initiatives for rehabilitating degraded mountain landscapes through macro-level global/national initiatives, mountain specific planning and development efforts is severely lacking in many areas on the Hindu Kush Himalayan region. Therefore, there is an urgent need for widening the scope of efforts directed to help mountain areas and communities, and a future thinking approach to enhance the sustainability of mountain areas as they are a valuable natural resource for humankind. This paper discusses the issues, opportunities, and provides suggestions for the future of mountain development.
基金Financial supports for these works come from Bayer CropScienceIndian Council of Agricultural Research(ICAR)CGIAR’s research program(CRP)on Climate Change Agriculture and Food Security(CCAFS)
文摘Achieving sustainability of the cereal system in the Indo-Gangetic Plains(IGP)of India under progressive climate change and variability necessitates adoption of practices and technologies that increase food production,adaptation and mitigation in a sustainable way.This paper examines conservation agriculture(CA)from the perspective of:(i)increased yield and farm income,(ii)adaptation to heat and water stresses,and(iii)reduction in greenhouse gas(GHGs)emissions.The analyses and conclusions are based on the literature and evidences from a large number of on-station as well as farmers’field trials on CA in the cereal systems of IGP.Our analyses show that CA-based system substantially reduces the production cost(up to 23%)but produces equal or even higher than conventional system;thereby increasing economic profitability of production system.CA-based production systems also moderated the effect of high temperature(reduced canopy temperature by 1–4°C)and increased irrigation water productivity by 66–100%compared to traditional production systems thus well adapting to water and heat stress situations of IGP.Our continuous monitoring of soil flux of CO2,N2O and CH4 revealed that CA-based rice-wheat systems emit 10–15%less GHGs than conventional systems.This is the first time that CA and its components are synthesized and analyzed from food security-climate change nexus.From this holistic analysis,we suggest that wide-scale promotion of suitable CA practices by integrating into national agriculture development strategy is a way forward to address food security,climate change adaptation and mitigation challenges faced by present agriculture.
基金Supported by National College Students Innovation Program in 2009(091029532)
文摘On the basis of expounding the research results of using relevant knowledge about Game Theory for supply chain of agricultural products at home and abroad,we use principal-agent model in Game Theory to research the new function that the supermarkets entrust supervision and control over quality of agricultural products to agricultural brokers in the circulation model of connecting agriculture with supermarkets;then design the optimal incentive contract and influencing factors between agricultural broker and supermarket,and explain the fundamental role of agricultural brokers in the process of circulation;finally in light of the role of government in promoting development and application of agricultural brokers,put forward corresponding policy suggestions:establish government support policy;set relevant standard of industry;establish cooperative organizations of agricultural brokers.
文摘The theory of multibody system dynamics is used to simulate valve trains' kinematics and dynamics characteristics, and the methods of establishing and analyzing the multibody system dynamics model for valve trains are discussed. Since most of the flexible bodies of a valve train are slender parts, the finite segment method is used to build their models. Other parts such as cams, valve heads etc., are built as rigid bodies. After applying the constraints, forces and motions, the establishing of the whole system is accomplished, and the Lagrange's multiplier method can be used to obtain its dynamics constitutive equations. As an example, a valve trains multibody system model of 4100QB engine made by the Yunnan Internal Combustion Engine Limited Liability Company is established, and the analysis results obtained show that its working performance is generally good except that the air pass ability and the lubrication effect of the cam and the tappet have to be improved.
文摘The paper deals with a transformation model of a backward distric into a prosperous one. The district is geographically located in Lixiahe region, Jiangsu Province. The region had long ben known as one of the poorest area in China, and had been alternatively attacked by flood, waterlogging, drought, salinzation, and plague of insect. Since the seventies of this centruy efforts to open up trenches on lowland and to level up the shoaly land have been made. A kind of tree, which is tolerable to high watertable, was used to afforest the land. Cereal crop, vegetable and beaus are grown. In some cases, the shoaly land is used for sheep grazing and fishery. A favorable combination of forestry, agriculture, animal husbandry and fishery has been set up in the region. There are five type of managements in the system: 1) forestry-agriculture comPlex management. 2) forestry-fishery complex management, 3) forestry-aquatic plan-fishery complex management, 4) forestry-animal husbandry complex management, and 5) forestry-edible mushroom complex management. The principles and ecological benefits of this system can be identitied: 1) Increase soil fertility by piling mud from marsh land on top soil, and thicken the arable layer. 2) Enhance the utilization rate of sunlight and energy, due to the change of microclimate in field. 3) As a result of multiple layer cultivation and multi-cropping, the production has been greatly increased. 4) Accelerate the cycling of matter and conversion of energy and nutrient of the system. 5) Decrease the consUmption of soil fertility and increase the capability of controlling insect pests. 6) Improve ecological environment by afforestationl. 7) Raise income and provide jobs for local peasants, even some ones from other part of this province.
文摘China is a great agricultural country with large population, limited soilresources and traditional farming mode, so the central government has been attaching greatimportance to the development of agriculture and put forward a new agricultural technologyrevolution ― the transformation from traditional agriculture to modern agriculture and fromextensive farming to intensive farming. Digital agriculture is the core of agriculturalinformatization. The enforcement of digital agriculture will greatly promote agricultural technologyrevolution, two agricultural transformations and its rapid development, and enhance China'scompetitive power after the entrance of WTO. To carry out digital agriculture, the frame system ofdigital agriculture is required to be studied in the first place. In accordance with the theory andtechnology of digital earth and in combination with the agricultural reality of China, this articleoutlines the frame system of digital agriculture and its main content arid technology support.
文摘Current status of several management models of the agriculture industry is introduced,as well as its impacts on industrial security.The management models are mainly the enterprise-like operation model,"enterprise + peasant household" model,small-scale peasants' operation model,and peasant specialized cooperative model.Functions of peasant specialized cooperative in ensuring the security of agricultural industry are introduced,which are enhancing the industrial security by organization degree,promoting the industrial security by scale economy formed by cooperative organizations,fully utilizing the resources by the factor allocation capability,and ensuring the industrial security by industrial chain improvement.Development predicaments of the peasant specialized cooperative at present are analyzed,such as small scale,poor economic benefits,and non-standard operation.Analysis shows that institutional absence is the main reason causing these predicaments.And suggestions on improving the cooperatives system in the Law of the People's Republic of China on Peasants Specialized Cooperatives are put forward,in order to better ensure the security of agriculture