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Urban economic efficiency under the interactive effect of urban hierarchy and connection networks in China 被引量:1
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作者 ZHOU Ying ZHENG Wensheng +1 位作者 WANG Xiaofang DU Nanqiao 《Journal of Geographical Sciences》 SCIE CSCD 2024年第12期2315-2332,共18页
The efficient development of the urban economy is a major concern of scholars in the fields of geography and urban science.In the context of globalization,informatization,industrialization,and urbanization,the externa... The efficient development of the urban economy is a major concern of scholars in the fields of geography and urban science.In the context of globalization,informatization,industrialization,and urbanization,the external relationships of China's cities are experiencing the joint action of urban scale hierarchies and connection networks(“hierarchy-network”).However,under the interactive effect of the two,the mechanism of urban economic efficiency(UEE)is unclear.Therefore,based on Baidu migration data,the regionalization with dynamically constrained agglomerative clustering and partitioning(REDCAP)method,and a spatial simultaneous equation model,this paper analyzes the UEE spatial pattern and mechanism in China.The results indicate that:(1)the urban economy has a superlinear relationship with the population size.However,the benefit of this superlinear growth is in marginal decline.(2)The UEE shows a pattern of differentiation between China's eastern,then central,and then western region.Also,local differences are found within the three major sub-regions.(3)The increase of urban network centrality can promote UEE,while the impact of urban scale is negative.(4)There is regional heterogeneity of the interactive effect of“hierarchy-network”on UEE.This study reveals the influencing mechanism of UEE and also provides policy implications for the development of UEE. 展开更多
关键词 urban economic efficiency urban scale hierarchies connection networks interactive effect China
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Spatial-temporal Divergence Characteristics and Driving Factors of Green Economic Efficiency in the Yangtze River Economic Belt of China 被引量:1
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作者 PAN Ting JIN Gui +1 位作者 ZENG Shibo WANG Rui 《Chinese Geographical Science》 SCIE CSCD 2024年第6期1158-1174,共17页
The spatial and temporal variation of green economic efficiency and its driving factors are of great significance for the construction of high-efficiency and low-consumption green development model and sustainable soc... The spatial and temporal variation of green economic efficiency and its driving factors are of great significance for the construction of high-efficiency and low-consumption green development model and sustainable socio-economic development.The research focused on the Yangtze River Economic Belt(YREB)and employed the miniumum distance to strong efficient frontier DEA(MinDs)model to measure the green economic efficiency of the municipalities in the region between 2008 and 2020.Then,the spatial autocorrelation model was used to analyze the evolution characteristics of its spatial pattern.Finally,Geodetector was applied to reveal the drivers and their interactions on green economic efficiency.It is found that:1)the overall green economic efficiency of the YREB from 2008 to 2020 shows a W-shaped fluctuating upward trend,green economic efficiency is greater in the downstream and smallest in the upstream;2)the spatial distribution of green economic efficiency shows clustering characteristics,with multi-core clustering based on‘city clusters-central cities'becoming more obvious over time;the High-High agglomeration type is mainly clustered in Jiangsu and Zheji-ang,while the Low-Low agglomeration type is clustered in the western Sichuan Plateau area and southwestern Yunnan;3)from input-output factors,whether it is the YREB as a whole or the upper,middle and lower reaches regions,the economic development level,labor input,and capital investment are the leading factors in the spatial-temporal evolution of green economic efficiency,with the com-prehensive influence of economic development level and pollution index being the most important interactive driving factor;4)from so-cio-economic factors,information technology drivers such as government intervention,transportation accessibility,information infra-structure,and Internet penetration are always high impact influencers and dominant interaction factors for green economic efficiency in the YREB and the three major regions in the upper,middle and lower reaches.Accordingly,the article puts forward relevant policy re-commendations in terms of formulating differentiated green transformation strategies,strengthening network leadership and informa-tion technology construction and coordinating multi-factor integrated development,which could provide useful reference for promoting synergistic green economic efficiency in the YREB. 展开更多
关键词 green economic efficiency miniumum distance to strong efficient frontier DEA(MinDs) spatial-temporal evolution Geo-detector Yangtze River economic Belt(YREB) China
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The impact of industrial transformation on green economic efficiency:New evidence based on energy use
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作者 Jin-Xing Jiang Jing-Jing Wang Yu Cheng 《Petroleum Science》 SCIE EI CAS CSCD 2024年第5期3644-3655,共12页
Developing a green economy is key to achieving the 2030 Sustainable Development Goals. This paper uses the SBM-GML index, which includes non-desired outputs, to measure the trend of regional green economic efficiency ... Developing a green economy is key to achieving the 2030 Sustainable Development Goals. This paper uses the SBM-GML index, which includes non-desired outputs, to measure the trend of regional green economic efficiency changes and analyze the impact mechanism and realization path of industrial transformation on green economic efficiency. The research results show that advanced industrial structure has a positive influence on green economic efficiency nationwide, while energy utilization structure and energy utilization efficiency have positive partial intermediary effects in the influence path;industrial structure rationalization is also significantly positively related to green economic efficiency nationwide, and the mediating effect of energy utilization is positive. The impact of industrial transformation on green economic efficiency has regional heterogeneity, and the mediating effect of energy use also differs. Among them, the impact effect in the eastern region is basically consistent with the national sample, but is negative in the central and western regions. This paper proposes countermeasures in terms of adjusting the industrial structure, improving energy efficiency, and perfecting industrial and energy policies, which can provide theoretical and practical references for promoting the transformation and upgrading of regional industrial structure, optimizing energy utilization, and advancing the efficiency of the national and regional green economy. 展开更多
关键词 Industrial transformation Energy use Green economic efficiency The SBM-GML model Mediating effect model
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Measurement of Technical, AIIocative and Economic Efficiency of Tomato Farms in Northern Pakistan 被引量:10
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作者 Himayatullah Khan 《Journal of Agricultural Science and Technology(B)》 2012年第10期1080-1090,共11页
The study measures productive efficiency of tomato growers in village Akbarpura of Disctrict Nowshera in Khyber Pakhtunkhwa (KPK) province of Northern Pakistan. The study uses household level data collected in summe... The study measures productive efficiency of tomato growers in village Akbarpura of Disctrict Nowshera in Khyber Pakhtunkhwa (KPK) province of Northern Pakistan. The study uses household level data collected in summer 2010 from sample farmers selected by multi-staged sampling. The study uses a theoretical framework to measure productive efficiency and estimates the Cobb-Douglas frontier production and cost models. The study found that technical efficiency indices varied significantly, with technical efficiency index averaging at 65%. The indices of allocative efficiency also varied widely, with an average of 56%. There was a wide gap between the highest and lowest economic efficiency indices, with a mean economic efficiency of 35%. The study concluded that farmer education, extension visits, age and access to credit contributed significantly and positively to productive efficiencies. A policy implication of this study is that there is enough potential for farmers to increase tomato production and net profits. The study recommends that the government should further invest in public education and strengthen extension services farmer education and because extension visits constituted important determinants of productive efficiencies. 展开更多
关键词 Frontier production and cost function technical efficiency allocative efficiency economic efficiency inefficiencydeterminants Pakistan.
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Rural Financial Development and Rural Economic Efficiency Improvement Based on Granger Causality Test
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作者 ZENG Guo-ping XU Xin-fang 《Asian Agricultural Research》 2010年第6期9-13,共5页
Based on the co-integration test theory,Financial Interrelation Ratio(FIR),level of financial efficiency(LFE),level of financial development(LFD) and other indices evaluating the rural financial development are select... Based on the co-integration test theory,Financial Interrelation Ratio(FIR),level of financial efficiency(LFE),level of financial development(LFD) and other indices evaluating the rural financial development are selected by Granger Causality Test.The rural loan balance(RLB),rural deposit balance(RDB),total rural output(TRO),fixed assets investment(FAI),Financial Interrelation Ratio(FIR),economic efficiency(EE),level of financial efficiency(LFE),and level of financial development(LFD) in the years 1979-2007 are collected.Graphical method intuitively reflects the development trend and historical track of relevant indices;and Granger Causality Test verifies the relationship between rural financial development level and rural economic efficiency in the years 1979-2007.Result shows that rural financial development level has significant impact on rural economic growth,but rural economic growth has no significant impact on rural financial development;and rural financial development also has insignificant promotion impact on rural economic efficiency.Thus,conclusions are obtained.Although rural financial development has made certain contribution to the development of rural economy,this kind of contribution is only reflected in total quantity,but not efficiency.Therefore,government should further strengthen the promotion function of financial development for economic efficiency,and gradually establish a virtuous circle system for rural finance and economic development. 展开更多
关键词 Rural finance economic efficiency Granger Causality Test China
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Effect of cumin intercropping density on cotton growth and system economic benefits under subsurface drip irrigation
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作者 DENG Shijie ZHANG Humei +6 位作者 SHI Feng LIU Xuan SHI Xiaojuan LI Nannan ZHAO Houxiu LUO Honghai TIAN Yu 《Journal of Cotton Research》 2025年第2期256-269,共14页
Background The mulch-free subsurface drip irrigation system demonstrated water-saving potential as an alternative to traditional mulch-based drip irrigation while also eliminating residual film pollution at source.How... Background The mulch-free subsurface drip irrigation system demonstrated water-saving potential as an alternative to traditional mulch-based drip irrigation while also eliminating residual film pollution at source.However,delayed sowing is unavoidable in mulch-free cultivation in ecological regions with a short frost-free period.Intercropping with cumin,which has a shorter growth period,served as an effective strategy to improve land use efficiency during the early growth stages of cotton.Therefore,a two-year field experiment was conducted to study the effects of intercropping cumin at the seeding rate of 2.5(ID1),3.85(ID2),and 5.2(ID3)kg・hm−2 on cotton growth,interspecies competition,fiber quality,and water use efficiency(WUE),as well as system economic benefits under subsurface drip irrigation.Monocropping cotton was used as the control(CK)treatment.Results At the initial flowering(IF)stage(the end of the co-growth period of cotton and cumin),cotton plant height in ID2 and ID3 treatments decreased by 5.93%–16.53%and 10.87%–31.11%,respectively,cotton stem diameter by 11.41%–14.25%and 3.37%–26.49%,respectively,and vegetative biomass by 14.46%–30.65%and 22.59%–49.91%,respectively,compared with CK treatment.With the increase in cumin density,the crop growth rate(CGR)and compensation effect in cotton tended to significantly decrease at the IF stage regardless of organs considered.For the non-co-growth period(after harvesting cumin),cotton reproductive organ biomass in ID2 and ID3 treatments increased by 4.09%‒14.61%at the boll opening stage,crop growth rate in reproductive organs by 20.74%and 74.26%from peak boll to boll opening stages compared with CK treatment,due to an enhancement of 19.09%and 49.30%in the compensation effect.Compared with ID1,the aggressivity treated by ID2 and ID3 decreased by 12.82%–46.34%and 17.95%–31.71%,respectively.However,owing to a greater number of green bolls in the upper canopy at the harvest stages in the ID3 treatment,the system production value(closely related to yield)treated by ID2 was 11.69%–16.89%,6.56%–20.02%,and 16.48%–59.83%greater than that of the ID1,ID3,and CK treatments,respectively.This also led to the highest WUE and net profit under the ID2 treatment.Conclusion Intercropping cumin with medium density improved the cotton biomass accumulation characteristics and increased resources such as land and water utilization efficiency and economic benefits through a stronger compensation effect after harvesting cumin under subsurface drip irrigation without mulch.This study not only provides alternatives to residual film pollution in arid cotton fields but also establishes a sustainable agro-ecological-economic planting paradigm by reducing plastic use and enhancing water and fertilizer use efficiency,holding significant implications for advancing resource-efficient agricultural systems. 展开更多
关键词 Cotton intercropping with cumin Subsurface drip irrigation BIOMASS Interspecific competition economic efficiency Resource competition
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Green economic efficiency in the Yangtze River Delta:spatiotemporal evolution and influencing factors 被引量:4
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作者 Zhenbo Wang Xinming Wang Longwu Liang 《Ecosystem Health and Sustainability》 SCIE 2019年第1期20-35,I0014,共17页
Based on economic-social-resource-environment perspective,which people’s welfare was considered compared with the traditional perspective,using SSU and PP model,spatial analysis method,spatial econometric model to st... Based on economic-social-resource-environment perspective,which people’s welfare was considered compared with the traditional perspective,using SSU and PP model,spatial analysis method,spatial econometric model to study green economy efficiency(GRE)of 26 Cities in the Yangtze River Delta from 2005 to 2015.The results show the following:Corrected GRE is markedly lower than conventional efficiency;Stage characteristics are obvious of GRE.An overall spatial pattern has emerged of lower efficiency in the east and higher efficiency in the west,and exist clear signs of spatial agglomeration.The spatial Dubin model has abetter fitting effect.The biggest direct effect on local green economic efficiency and spatial spillover effects on nearby areas is proportion of tertiary industry. 展开更多
关键词 Green economic efficiency measurement and calculation spatial characteristics influencing factors Yangtze River Delta urban agglomeration spatial econometrics
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Eco-Efficiency: Environmental Performance vs Economic Performance
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作者 Antonio Arbelo Pilar Perez-Gomez, Felipe Manuel Rosa-Gonzalez Libertad Ramos 《Management Studies》 2014年第4期239-253,共15页
The second half of the 20th century was characterized by an increasing interest in the pace of economic growth and its impact on the environment. As a result, the concept of eco-efficiency as a philosophy of managemen... The second half of the 20th century was characterized by an increasing interest in the pace of economic growth and its impact on the environment. As a result, the concept of eco-efficiency as a philosophy of management has arisen, which combines the excellence of the environment and business. This paper uses the distribution-free approach to provide empirical evidence in relation to the eco-efficiency paradigm by studying the relation between environmental performance (measured by the level of emissions of air-contaminating substances) and economic performance (approximated by economic efficiency), in 199 companies from mineral manufacturing industry in Spain between 2004 and 2007. The empirical analysis shows that the results are consistent with the paradigm of eco-efficiency and therefore it can be concluded that being responsible for the environment is positively related to economic efficiency. 展开更多
关键词 ECO-efficiency economic efficiency environmental performance distribution-free approach
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Effect of Agricultural Land Use Changes on Soil Nutrient Use Efficiency in an Agricultural Area,Beijing,China 被引量:5
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作者 CHEN Liding QI Xin +2 位作者 ZHANG Xinyu LI Qi ZHANG Yanyan 《Chinese Geographical Science》 SCIE CSCD 2011年第4期392-402,共11页
Agricultural land use and management practices may affect soil properties,which play a critical role in sustaining crop production.Since the late 1970s,several new agricultural land use types had been introduced in th... Agricultural land use and management practices may affect soil properties,which play a critical role in sustaining crop production.Since the late 1970s,several new agricultural land use types had been introduced in the rural areas of China.The purpose of this study is to evaluate the effect of these land use changes on the soil properties,nu-trient absorption rate,and nutrient use economic efficiency ratio in an agricultural area of Beijing.Specifically,the cropland,the orchard and the vegetable field were examined.Results of this study suggest that land use and farming management practices significantly affect the content of soil organic carbon (SOC),total nitrogen (TN),total phos-phorus (TP),and available phosphorus in the surface layer of 0-25 cm (p<0.05) in the Yanqing Basin,northwestern Beijing.Soil nutrients in each agricultural land use type decrease rapidly with the increasing soil depth.Orchard and vegetable field tend to have higher soil nutrients than the cropland does.However,the soil nutrient-absorption rate (NAR) of the orchard and vegetable field is lower than that of the cropland,even though orchard and vegetable field may provide much higher economic benefit.While increasing SOC,TN,and TP in the orchard and vegetable field by intensive farming may be a valuable option to improve soil quality,potential increase in the risk of nutrient loss,or agricultural non-point source pollution can be a tradeoff if the intensive practices are not managed appropriately. 展开更多
关键词 agricultural land use soil nutrient absorption rate (NAR) soil nutrient use economic efficiency ratio (NEER) soil property environmental effect
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Economic Evaluation of the Resource-Saving Technologies in Non-irrigated Lands
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作者 Iroda Rustamova 《Journal of Agricultural Science and Technology(A)》 2016年第4期211-219,共9页
Conservation agriculture (CA) is especially relevant for Uzbekistan's agriculture, particularly in non-irrigated lands where soil fertility has been steadily declining and the risk of crop failure has been growing.... Conservation agriculture (CA) is especially relevant for Uzbekistan's agriculture, particularly in non-irrigated lands where soil fertility has been steadily declining and the risk of crop failure has been growing. CA has three main characterizations given in scientific literature, which are the minimal soil disturbance, crop rotation and surface crop residue retention. Nowadays, the majority of farmers are not widely using CA in their agricultural practices in Uzbekistan. Maybe, this is due to different perception of the economic efficiency of CA. The objective of the research was to calculate economic efficiency of CA in non-irrigated lands and to show whether it is effective or not in agricultural production. To achieve this objective, literature review including a variety of secondary data is employed. Overall, the costs of labor and fuel consumption per ha at CA technology are less in comparison with conventional technology. Using CA practices gives a chance to increase labour productivity, to use resource effectively and to improve soil quality and crop diversification. 展开更多
关键词 Conservation agriculture PRODUCTIVITY economic efficiency COSTS PROFIT Uzbekistan.
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Oppugnation on the Efficiency of the Perfect Competitive Market
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作者 Huai'an Wei 《Chinese Business Review》 2003年第1期46-51,共6页
In the classical economic prevalent opinions, economic efficiency is in direct proportion to the level of the market competitiveness and perfect competitive market has the highest efficiency. However, in this paper, i... In the classical economic prevalent opinions, economic efficiency is in direct proportion to the level of the market competitiveness and perfect competitive market has the highest efficiency. However, in this paper, it will be approved the viewpoint that perfect competitive market owns highest efficiency is not existent in practical economy, even on the theoretic level, uncertainty exits. So the perfect objective model the government oolicv should oursue is coexistence of the effective competition and effective monopoly. 展开更多
关键词 perfect competition effective competition effective monopoly economic efficiency
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Economic Analysis of the Use of Restrictive Food Management in the Cultivation of Tilapia(Oreochromis niloticus)in a Recirculation System
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作者 Giovanni Resende de Oliveira Thiago Archangelo Freato +3 位作者 Juan Daniel Villacis Fajardo Tainára Cunha Gemaque Nancy Andrea Villacis Fajardo Daniel Pereira da Costa 《Journal of Agricultural Science and Technology(B)》 2022年第2期31-39,共9页
The development of more adequate food programs regarding the intensity and duration of the restriction can be an effective way to minimize the effects of exaggerated food consumption and its negative consequences for ... The development of more adequate food programs regarding the intensity and duration of the restriction can be an effective way to minimize the effects of exaggerated food consumption and its negative consequences for the economy of the business.In this sense,juvenile Nile tilapia(Oreochromis niloticus)(137±3 g)were submitted to different feeding strategies in a recirculation system.Five feeding strategies were tested in subsequent weekly cycles:continuous feeding;skipping one meal a week;suppression of two non-consecutive meals a week;suppression of three non-consecutive meals a week;suppression of four non-consecutive meals a week.Productive performance,feed consumption in the post-restriction period and economic indicators were evaluated through projections and profitability analyses.Compensatory intake occurred in all tested groups,so that the total feed intake(FI)did not differ significantly between them(p>0.05).Moderate food restriction provided a linear increase in the relative gross margin for each treatment with each change in salary level,as well as greater profitability when compared to the respective control group(p<0.05). 展开更多
关键词 Feed management feed restriction carcass quality carcass yield operational yield economic efficiency
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Measurement of Economic Power: An Engineering Approach
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作者 Mohammed Safiuddin 《Journal of Modern Accounting and Auditing》 2017年第4期162-173,共12页
Business Directory defines economic power as "conditions of having sufficient productive resources at command that give the capacity to make and enforce economic decisions, such as allocation of resources and apporti... Business Directory defines economic power as "conditions of having sufficient productive resources at command that give the capacity to make and enforce economic decisions, such as allocation of resources and apportioning of goods and services". This qualitative definition may be sufficient for general discussions, but it does not offer any quantitative measurements for management and control. Is there a way to measure economic power for analysis and synthesis of economic systems in this 21st century? This paper answers this question by introducing a set of quantitative terms from the field of electrical engineering, used in power measurement and control of electrical systems. Circuit theory concepts are introduced to show how the relationship between cash and cash flow in finance is analogous to that of electric charge and electric current and how education level, as economic potential, is analogous to electrical potential that causes current to flow in a circuit. An individual is identified as the basic cash flow source in the economy. Circuit models for an individual as well as a typical production facility are developed and demonstrated with an example. Equations for the measurement of economic power, losses, efficiency, and power factor are presented. It is shown that the individuals are the basic cash flow sources and producers of economic power. 展开更多
关键词 economic power economic potential economic efficiency
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Feminist Perspective on Economic Theory, Policies, and Institutions for Women Workers in the Informal Employment of Indonesian Post-economic Crisis
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作者 Hesti R. Wijaya 《Sociology Study》 2012年第9期645-661,共17页
This paper aims to have a grounded picture regarding the impacts of the economic crises on women workers in the informal employment, identify the economic theory whose application is disadvantageous to the women home-... This paper aims to have a grounded picture regarding the impacts of the economic crises on women workers in the informal employment, identify the economic theory whose application is disadvantageous to the women home-based workers, support recognition of women homeworkers by the policy makers, and empower the workers through exercising their rights. Research methodology for women's studies from a feminist perspective is employed covering action-oriented research initiating from the grounded issues, a bottom-up approach, and a participatory method where the researchers act as facilitators. It is necessarily a longitudinal research work with a new paradigm to change the women's situation. This methodology is deemed effective to identify impacts of the crises as described in the paper. It can be found that the root cause of women workers' exploitation is the economic efficiency theory, while policy development should be specifically designed along with engendering policy makers. Exercising the rights to organize the unorganized women home-based workers is no way repeatable from standard practice of organizing formal workers. All these require action of committed and skilled feminists with adequate praxis resources. 展开更多
关键词 Impacts of economic crises economic efficiency theory policy development grassroots organization women home-basedworkers
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Estimating the Efficiency of Summer Tomatoes Production: A Case Study in Borg El-Arab Area, Egypt
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作者 Zainab Shawky El-Khalifa Ahmed Ayoub Hoda Farouk Zahran 《Open Journal of Applied Sciences》 2022年第6期855-864,共10页
Tomatoes are one of the most popular and widely consumed vegetable crops worldwide. Egypt is characterized by its tomatoes production, whether for domestic use or export. Summer tomato farmers’ income has recently be... Tomatoes are one of the most popular and widely consumed vegetable crops worldwide. Egypt is characterized by its tomatoes production, whether for domestic use or export. Summer tomato farmers’ income has recently been reduced due to high production costs, particularly in new lands. As a result, the purpose of this research is to evaluate the economic efficiency of the elements used in summer tomato production in the Borg El-Arab area of Egypt as a new land. According to the findings, the summer tomato crop produced a reasonable profit for small-holding farmers in the study area. However, the elements are being used excessively in the production process, particularly seeds and fertilizers, resulting in increased production costs and failure to achieve economic efficiency of the elements used in the study area. 展开更多
关键词 economic efficiency Summer Tomatoes Production Costs economic Indicators Borg El-Arab Area New Lands
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Industrial Green Spatial Pattern Evolution of Yangtze River Economic Belt in China 被引量:3
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作者 LI Lin LIU Ying 《Chinese Geographical Science》 SCIE CSCD 2017年第4期660-672,共13页
We use the directional slacks-based measure of efficiency and inverse distance weighting method to analyze the spatial pattern evolution of the industrial green total factor productivity of 108 cities in the Yangtze R... We use the directional slacks-based measure of efficiency and inverse distance weighting method to analyze the spatial pattern evolution of the industrial green total factor productivity of 108 cities in the Yangtze River Economic Belt in 2003–2013.Results show that both the subprime mortgage crisis and ‘the new normal' had significant negative effects on productivity growth,leading to the different spatial patterns between 2003–2008 and 2009–2013.Before 2008,green poles had gathered around some capital cities and formed a tripartite pattern,which was a typical core-periphery pattern.Due to a combination of the polarization and the diffusion effects,capital cities became the growth poles and ‘core' regions,while surrounding areas became the ‘periphery'.This was mainly caused by the innate advantage of capital cities and ‘the rise of central China' strategy.After 2008,the tripartite pattern changed to a multi-poles pattern where green poles continuously and densely spread in the midstream and downstream areas.This is due to the regional difference in the leading effect of green poles.The leading effect of green poles in midstream and downstream areas has changed from polarization to diffusion,while the polarization effect still leads in the upstream area. 展开更多
关键词 Yangtze River economic Belt industrial green total factor productivity directional slacks-based measure of efficiency inverse distance weighting spatial pattern evolution
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Optimizing Nitrogen Fertilizer Application for Rice Production in the Taihu Lake Region,China 被引量:13
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作者 DENG Mei-Hua SHI Xiao-Jun +4 位作者 TIAN Yu-Hua YIN Bin ZHANG Shao-Lin ZHU Zhao-Liang S.D.KIMURA 《Pedosphere》 SCIE CAS CSCD 2012年第1期48-57,共10页
To determine the optimal amount of nitrogen(N) fertilizer for achieving a sustainable rice production at the Taihu Lake region of China,two-year on-farm field experiments were performed at four sites using various N a... To determine the optimal amount of nitrogen(N) fertilizer for achieving a sustainable rice production at the Taihu Lake region of China,two-year on-farm field experiments were performed at four sites using various N application rates.The results showed that 22%-30% of the applied N was recovered in crop and 7%-31% in soils at the rates of 100-350 kg N ha 1.Nitrogen losses increased with N application rates,from 44% of the applied fertilizer N at the rate of 100 kg N ha 1 to 69% of the N applied at 350 kg N ha 1.Ammonia volatilization and apparent denitrification were the main pathways of N losses.The N application rate of 300 kg N ha 1,which is commonly used by local farmers in the study region,was found to lead to a significant reduction in economic and environmental efficiency.Considering the cost for mitigating environmental pollution and the maximum net economic income,an application rate of 100-150 kg N ha 1 would be recommended.This recommended N application rate could greatly reduce N loss from 199 kg N ha 1 occurring at the N application rate of 300 kg N ha 1 to 80-110 kg N ha 1,with the rice grain yield still reaching 7 300-8 300 kg DW ha 1 in the meantime. 展开更多
关键词 economic efficiency environmental efficiency N application rate N loss rice grain yield
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An estimation framework of regional rooftop photovoltaic potential based on satellite remote sensing images 被引量:4
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作者 Boyu Chen Yanbo Che +3 位作者 Jingkai Wang Hongfeng Li Linjun Yu Dacheng Wang 《Global Energy Interconnection》 EI CAS CSCD 2022年第3期281-292,共12页
This paper proposes a comprehensive framework for estimating the regional rooftop photovoltaic(PV)potential.The required rooftop information is extracted from Gao Fen-7 satellite images.In particular,the rooftop area ... This paper proposes a comprehensive framework for estimating the regional rooftop photovoltaic(PV)potential.The required rooftop information is extracted from Gao Fen-7 satellite images.In particular,the rooftop area is obtained using a semantic segmentation network.The azimuth and inclination angles are calculated based on the digital surface model.In addition,to improve the accuracy of the economic evaluation,buildings are divided into commercial and industrial buildings and residential buildings.Based on the difference in the roof inclination,the rooftops can be divided into flat roofs,on which the PV panels are installed with the optimal inclination angle,and sloped rooftops,on which the PV panels are installed in a lay-flat manner.The solar irradiation on the plane-of-array is calculated using the isotropic sky translocation model.Then,the available installed capacity and generation potential of the rooftop PV is obtained.Finally,the net present value,dynamic payback period,and internal rate of return are used to evaluate the economic efficiency of the rooftop PV project.The proposed framework is applied in the Da Xing district of Beijing,China,with a total area of 546.84 km^(2).The results show that the rooftop area and available installed capacity of PV are 25.63 km^(2)and 1487.45 MWp,respectively.The annual rooftop PV generation potential is 2832.23 GWh,with significant economic returns. 展开更多
关键词 Rooftop PV Potential estimation economic efficiency evaluation GF7 satellite image
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Leaf area development, dry weight accumulation and solar energy conversion efficiencies of Phaseolus vulgaris L. under different soil moisture levels near Nairobi, Kenya 被引量:2
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作者 M.M.Muniafu J.N.M.Macharia +1 位作者 C.J.Stigter G.L.Coulson 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1999年第4期449-456,共8页
Leaf area development, dry weight accumulation and solar energy conversion efficiencies of Phaseolus vulgaris L. cv GLP\|2 under two soil moisture levels in two contrasting seasons near Nairobi, Kenya were investigate... Leaf area development, dry weight accumulation and solar energy conversion efficiencies of Phaseolus vulgaris L. cv GLP\|2 under two soil moisture levels in two contrasting seasons near Nairobi, Kenya were investigated. The experiment confirms that dry weights and yields of Phaseolus vulgaris are limited by a drought induced decrease in leaf area, leading to less radiation interception as a source for assimilation. However, photosynthetic efficiency in Phaseolus vulgaris also appears to decrease and to contribute to these effects. Finally, an even larger decreases of economic efficiency as obtained in the second season, where stress lasted much later into the season, reveals that such a drought also limits considerably the partitioning and translocation of assimilates to the seeds of Phaseolus vulgaris. The efficiencies obtained are in line with the better literature data for other crops. 展开更多
关键词 economic efficiency Phaseolus vulgaris L. photosynthetic efficiency radiation absorption/interception tube solarimeters
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Effect of Zinc Methionine Supplementation on Productive Performance of Lactating Friesian Cows 被引量:1
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作者 H. M. A. Gaafar M. I. Bassiouni +2 位作者 M. F. E. Ali A. A. Shitta A. Sh. E. Shamas 《Journal of Animal Science and Biotechnology》 SCIE CAS 2011年第2期94-101,共8页
Twelve lactating Friesian Cows with body weight of 450 to 550 kg and in the second to fifth lactating season were used after 8 weeks of cal- ving in a complete switch-back design. The cows were fed a basal ration of 3... Twelve lactating Friesian Cows with body weight of 450 to 550 kg and in the second to fifth lactating season were used after 8 weeks of cal- ving in a complete switch-back design. The cows were fed a basal ration of 35% concentrate feed mix-ture with 40% berseem and 25% rice straw ( on a dry matter (DM) basis) without supplementation ( G1 ) or supplemented with 5 and 10 g zinc methionine per head per day (G2 and G3, respectively). Nutrient digestibility coefficients and nutritive values were significantly increased (P 〈0.05) by zinc methionine supplementation. Cows in G2 had the highest feed intake of total digestible nutrients (TDN) and digestible crude protein (DCP), followed by Ga and G1, respectively ( P 〈 0.05 ). The ruminal total volatile fatty acid concentration increased and ammonia nitrogen decreased significantly ( P 〈 0.05 ) by zinc methio-nine supplementation. Cows in G3 showed the highest plasma total protein, albumin, and globulin concen- trations ( P 〈 0.05 ). Zinc methionine supplementa- tion led to significant decreases ( P 〈 0.05 ) in the activities of aspartate aminotransferase and alanine aminotransferase. A significant increase ( P 〈 0.05 ) was observed in the milk yield for G2 (2.54 kg/d or 18. 1% ) and G3 ( 1.95 kg/d or 14.2% ) compared with the control group. The corresponding increase in 4% fat-corrected milk (FCM) was 2.85 and 2.03 kg/d (21.63% and 15.74% ) for G2 and G3, respectively. Cows in G2 had the highest fat, total protein, and total solids contents, and the yield of all milk constitu- ents and animals in G3 showed the highest lactose, solids-not-fat, and ash contents. Zinc methionine sup- plementation improved feed conversion, reducing the quantities of DM, TDN, and DCP required to pro- duce 1 kg of 4% FCM (P〈0.05). The average dai- ly feed cost per kilogram of 4% FCM decreased and the average income from milk production increased with zinc methionine supplementation ( P 〈 0.05 ). Quadratic analysis showed that the optimal level of zinc methionine supplementation is 6 g per head per day in terms of milk yield and net revenue. 展开更多
关键词 DIGESTIBILITY economic efficiency feed conversion milk yield and composition rumen activity
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