[Ohjective] The aim of the study is to investigate the productivity and light quality in two high density M26 dwarf rootstock apple orchards in central China so as to provide some management guidance for close plantin...[Ohjective] The aim of the study is to investigate the productivity and light quality in two high density M26 dwarf rootstock apple orchards in central China so as to provide some management guidance for close planting of dwarf rootstock apples.[Method] The technical parameters of individual trees and group parameters as shoot number and composition and canopy coverage were determined, and the light quality in the canopy, fruit production and quality were investigated. [Result] Slender spindle （SS） orchard has 54 thousands shoots per 667 m^2. Coverage rate is 76%. Leaf area index is 1.9. The ratio of long, medium and spur shoots is 1：1：8. Fruit yield is 3 263 kg/667 m^2 with 85% first grade fruit. Light interception in the canopy is 58% while the ratio of canopy with good light is 65%. Modified slender spindle （MSS） orchard has 93 thousands shoots per 667 m^2 and the coverage is 77%. Leaf area index is 3.3. The ratio cf long, medium and spur shoots is 1：2：7. Fruit yield is 3 931 kg/667 m^2 with 85% first grade fruit. The light interception in the canopy is 73% while the ratio of canopy with good light is 35%. [Conclusion] Apple orchard with M26 dwarf rootstock trained as SS and MSS tree form in medium planting density may be useful to the management of the similar orchards in Central China.展开更多
Buffer influences the performance of production lines greatly.To solve the buffer allocation problem(BAP) in serial production lines with unreliable machines effectively,an optimization method is proposed based on an ...Buffer influences the performance of production lines greatly.To solve the buffer allocation problem(BAP) in serial production lines with unreliable machines effectively,an optimization method is proposed based on an improved ant colony optimization(IACO) algorithm.Firstly,a problem domain describing buffer allocation is structured.Then a mathematical programming model is established with an objective of maximizing throughput rate of the production line.On the basis of the descriptions mentioned above,combining with a two-opt strategy and an acceptance probability rule,an IACO algorithm is built to solve the BAP.Finally,the simulation experiments are designed to evaluate the proposed algorithm.The results indicate that the IACO algorithm is valid and practical.展开更多
Using meteorological data and RS dynamic land-use observation data set, the po-tential land productivity that is limited by solar radiation and temperature is estimated and the impacts of recent LUCC processes on it a...Using meteorological data and RS dynamic land-use observation data set, the po-tential land productivity that is limited by solar radiation and temperature is estimated and the impacts of recent LUCC processes on it are analyzed in this paper. The results show that the influence of LUCC processes on potential land productivity change has extensive and unbal-anced characteristics. It generally reduces the productivity in South China and increases it in North China, and the overall effect is increasing the total productivity by 26.22 million tons. The farmland reclamation and original farmlands losses are the primary causes that led potential land productivity to change. The reclamation mostly distributed in arable-pasture and arable-forest transitional zones and oasises in northwestern China has made total productivity increase by 83.35 million tons, accounting for 3.50% of the overall output. The losses of original farmlands driven by built-up areas invading and occupying arable land are mostly distributed in the regions which have rapid economic development, e.g. Huang-Huai-Hai plain, Yangtze River delta, Zhu-jiang delta, central part of Gansu, southeast coastal region, southeast of Sichuan Basin and Urumqi-Shihezi. It has led the total productivity to decrease 57.13 million tons, which is 2.40% of the overall output.展开更多
Objective:We aimed to explore the efficiency of community health centers(CHCs)in China from 2013 to 2015,providing policy suggestions for optimizing the allocation of health resources.Methods:Data on the efficiency of...Objective:We aimed to explore the efficiency of community health centers(CHCs)in China from 2013 to 2015,providing policy suggestions for optimizing the allocation of health resources.Methods:Data on the efficiency of CHCs in 30 provinces/autonomous regions/municipalities in China's Mainland(except Tibet)from 2013 to 2015 were collected from China’s Health and Family Planning Statistical Yearbook 2014,China’s Health and Family Planning Statistical Yearbook 2015,and China’s Health and Family Planning Statistical Yearbook 2016.Data envelopment analysis and Malmquist index analysis were performed to investigate the efficiency of sampled CHCs during this period at the national level and the regional level.The applied input indicators include the numbers of CHCs,community health workers,and beds,and the output indicators consist of the numbers of visits and inpatients,the occupancy rate of beds,and the average length of stay.Results:In 2015,the average annual overall technical efficiency,pure technical efficiency,and scale efficiency of CHCs in 30 regions at the national level were 0.715,0.705,and 0.972,respectively.Eight regions(Guangdong,Guizhou,Hainan,Ningxia,Qinghai,Shanghai,Zhejiang,and Chongqing,accounting for 26.7%of the total)had efficient CHCs with overall technical ef-ficiency of 1.000,and the other 22 regions had surpluses of 131 CHCs,5573 community health workers,and 2086 beds on average.In 2015,the average annual technical change index,pure technical efficiency change index,total factor productivity,technical efficiency change index,and scale efficiency change index of CHCs at the national level were 1.034,1.002,1.024,0.990,and 0.988,respectively.Compared with 2013,the former three increased by 3.4%,0.2%,and 2.4%,respectively,while the latter two decreased by 1.0%and 1.2%,respectively.Conclusion:On the whole,efficiency improvements of CHCs were achieved at the national level from 2013 to 2015,but with obvious interregional differences.In regions with inefficient CHCs identified by data envelopment analysis,there was a problem of coexistence of shortage and wastage of community health resources.In view of this,targeted measures should be taken to optimize the allocation of community health resources,and the management of CHCs should be strengthened to improve the efficiency of these institutions.展开更多
Ammonia is not only an important platform chemical for industrial and agri-cultural use but is also a novel energy-carrying molecule.The electrochemical reduction method for ambient ammonia synthesis is emerging as a ...Ammonia is not only an important platform chemical for industrial and agri-cultural use but is also a novel energy-carrying molecule.The electrochemical reduction method for ambient ammonia synthesis is emerging as a promising strategy for the replacement of the current Haber–Bosch ammonia synthesis method,which consumes a large amount of energy and natural gas(hydrogen resource)while releasing substantial greenhouse gases(eg,carbon dioxide).The challenges in electrochemical ammonia synthesis,also known as nitrogen reduc-tion reaction,primarily include the cleavage of extremely stable N≡N bonds and the competitive hydrogen evolution reaction in routine aqueous media,which significantly leads to a low production rate and Faradaic efficiency.The ratio-nal design and engineering of the electrocatalyst/electrolyte interface are crucial to address these challenges.Herein,recent achievements for catalyst/electrolyte interface engineering are reviewed to provide insights into enhancing the pro-duction rate and Faradaic efficiency.Perspectives on future research and devel-opment of the electrochemical ammonia synthesis from theory to practice will be provided.展开更多
基金Supported by National Apple Industry Programs of Ministry of Agriculture(CARS-28)~~
文摘[Ohjective] The aim of the study is to investigate the productivity and light quality in two high density M26 dwarf rootstock apple orchards in central China so as to provide some management guidance for close planting of dwarf rootstock apples.[Method] The technical parameters of individual trees and group parameters as shoot number and composition and canopy coverage were determined, and the light quality in the canopy, fruit production and quality were investigated. [Result] Slender spindle （SS） orchard has 54 thousands shoots per 667 m^2. Coverage rate is 76%. Leaf area index is 1.9. The ratio of long, medium and spur shoots is 1：1：8. Fruit yield is 3 263 kg/667 m^2 with 85% first grade fruit. Light interception in the canopy is 58% while the ratio of canopy with good light is 65%. Modified slender spindle （MSS） orchard has 93 thousands shoots per 667 m^2 and the coverage is 77%. Leaf area index is 3.3. The ratio cf long, medium and spur shoots is 1：2：7. Fruit yield is 3 931 kg/667 m^2 with 85% first grade fruit. The light interception in the canopy is 73% while the ratio of canopy with good light is 35%. [Conclusion] Apple orchard with M26 dwarf rootstock trained as SS and MSS tree form in medium planting density may be useful to the management of the similar orchards in Central China.
基金Supported by the National Natural Science Foundation of China(No.61273035,71471135)
文摘Buffer influences the performance of production lines greatly.To solve the buffer allocation problem(BAP) in serial production lines with unreliable machines effectively,an optimization method is proposed based on an improved ant colony optimization(IACO) algorithm.Firstly,a problem domain describing buffer allocation is structured.Then a mathematical programming model is established with an objective of maximizing throughput rate of the production line.On the basis of the descriptions mentioned above,combining with a two-opt strategy and an acceptance probability rule,an IACO algorithm is built to solve the BAP.Finally,the simulation experiments are designed to evaluate the proposed algorithm.The results indicate that the IACO algorithm is valid and practical.
基金the mgjor res each plan of the National Natural Science Foumndation of China(Gant No.90202002) the National Major Basic R.ecearch Projects(Gant No.2002CB412507).
文摘Using meteorological data and RS dynamic land-use observation data set, the po-tential land productivity that is limited by solar radiation and temperature is estimated and the impacts of recent LUCC processes on it are analyzed in this paper. The results show that the influence of LUCC processes on potential land productivity change has extensive and unbal-anced characteristics. It generally reduces the productivity in South China and increases it in North China, and the overall effect is increasing the total productivity by 26.22 million tons. The farmland reclamation and original farmlands losses are the primary causes that led potential land productivity to change. The reclamation mostly distributed in arable-pasture and arable-forest transitional zones and oasises in northwestern China has made total productivity increase by 83.35 million tons, accounting for 3.50% of the overall output. The losses of original farmlands driven by built-up areas invading and occupying arable land are mostly distributed in the regions which have rapid economic development, e.g. Huang-Huai-Hai plain, Yangtze River delta, Zhu-jiang delta, central part of Gansu, southeast coastal region, southeast of Sichuan Basin and Urumqi-Shihezi. It has led the total productivity to decrease 57.13 million tons, which is 2.40% of the overall output.
基金This study was supported by the grants from the National Natural Science Foundation of China(71704130)the special fund from the China Postdoctoral Science Foundation(2016T90211).
文摘Objective:We aimed to explore the efficiency of community health centers(CHCs)in China from 2013 to 2015,providing policy suggestions for optimizing the allocation of health resources.Methods:Data on the efficiency of CHCs in 30 provinces/autonomous regions/municipalities in China's Mainland(except Tibet)from 2013 to 2015 were collected from China’s Health and Family Planning Statistical Yearbook 2014,China’s Health and Family Planning Statistical Yearbook 2015,and China’s Health and Family Planning Statistical Yearbook 2016.Data envelopment analysis and Malmquist index analysis were performed to investigate the efficiency of sampled CHCs during this period at the national level and the regional level.The applied input indicators include the numbers of CHCs,community health workers,and beds,and the output indicators consist of the numbers of visits and inpatients,the occupancy rate of beds,and the average length of stay.Results:In 2015,the average annual overall technical efficiency,pure technical efficiency,and scale efficiency of CHCs in 30 regions at the national level were 0.715,0.705,and 0.972,respectively.Eight regions(Guangdong,Guizhou,Hainan,Ningxia,Qinghai,Shanghai,Zhejiang,and Chongqing,accounting for 26.7%of the total)had efficient CHCs with overall technical ef-ficiency of 1.000,and the other 22 regions had surpluses of 131 CHCs,5573 community health workers,and 2086 beds on average.In 2015,the average annual technical change index,pure technical efficiency change index,total factor productivity,technical efficiency change index,and scale efficiency change index of CHCs at the national level were 1.034,1.002,1.024,0.990,and 0.988,respectively.Compared with 2013,the former three increased by 3.4%,0.2%,and 2.4%,respectively,while the latter two decreased by 1.0%and 1.2%,respectively.Conclusion:On the whole,efficiency improvements of CHCs were achieved at the national level from 2013 to 2015,but with obvious interregional differences.In regions with inefficient CHCs identified by data envelopment analysis,there was a problem of coexistence of shortage and wastage of community health resources.In view of this,targeted measures should be taken to optimize the allocation of community health resources,and the management of CHCs should be strengthened to improve the efficiency of these institutions.
基金Natural Sciences and Engineering Research Council of Canada(NSERC)Fonds de Recherche du Québec-Nature et Technologies(FRQNT)+4 种基金Centre Québécois sur les Materiaux Fonctionnels(CQMF)Institut National de la Recherche Scien-tifique(INRS)National Natural Science Foundation of China,Grant/Award Num-bers:21805064,51803042International Postdoctoral Exchange Fellowship Pro-gram by the Office of China Postdoctoral Council,Grant/Award Number:20180072FRQNT for the Postdoctoral scholarship,Grant/Award Number:274384。
文摘Ammonia is not only an important platform chemical for industrial and agri-cultural use but is also a novel energy-carrying molecule.The electrochemical reduction method for ambient ammonia synthesis is emerging as a promising strategy for the replacement of the current Haber–Bosch ammonia synthesis method,which consumes a large amount of energy and natural gas(hydrogen resource)while releasing substantial greenhouse gases(eg,carbon dioxide).The challenges in electrochemical ammonia synthesis,also known as nitrogen reduc-tion reaction,primarily include the cleavage of extremely stable N≡N bonds and the competitive hydrogen evolution reaction in routine aqueous media,which significantly leads to a low production rate and Faradaic efficiency.The ratio-nal design and engineering of the electrocatalyst/electrolyte interface are crucial to address these challenges.Herein,recent achievements for catalyst/electrolyte interface engineering are reviewed to provide insights into enhancing the pro-duction rate and Faradaic efficiency.Perspectives on future research and devel-opment of the electrochemical ammonia synthesis from theory to practice will be provided.
