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Defining Cities by Water: Addressing Capital Misallocation in a Race to Conserve Resources
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作者 Yao Peng Li Jinze 《China Economist》 2024年第1期86-102,共17页
As part of its efforts to promote a sustainable and high-quality development,China has pledged to reduce water consumption and create a water-efficient society.On the basis of identifying the institutional root causes... As part of its efforts to promote a sustainable and high-quality development,China has pledged to reduce water consumption and create a water-efficient society.On the basis of identifying the institutional root causes of excessive capital allocation and excessive water consumption in China’s water-intensive industrial sectors,this study elaborates how the national water-efficient cities assessment contributes to optimized capital allocation.Our research shows that national water-efficient cities assessment has motivated local governments to compete for water efficiency.To conserve water,local governments regulated the entry and exit of water-intensive enterprises,discouraged excessive investments in water-intensive sectors,and phased out obsolete water-intensive capacities within their jurisdictions.This approach has resulted in mutually beneficial outcomes,including improved allocation of capital,enhanced water efficiency,and reduced emissions.This paper offers policy recommendations for establishing a water-efficient society throughout the 14^(th) Five-Year Plan(2021-2025)period by presenting empirical evidence on the policy effects of resource efficiency evaluation. 展开更多
关键词 Competitive evaluation for resource efficiency national water-efficient cities assessment capital misallocation water efficiency emissions abatement
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The Relationship between Water Resources Use Efficiency and Scientific and Technological Innovation Level: Case Study of Yangtze River Basin in China
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作者 Guangming Yang Qingqing Gui +2 位作者 Junyue Liu Fengtai Zhang Siyi Cheng 《Journal of Environmental & Earth Sciences》 2023年第2期15-35,共21页
The Yangtze River Basin’s water resource utilization efficiency(WUE)and scientific and technological innovation level(STI)are closely connected,and the comprehension of these relationships will help to improve WUE an... The Yangtze River Basin’s water resource utilization efficiency(WUE)and scientific and technological innovation level(STI)are closely connected,and the comprehension of these relationships will help to improve WUE and promote local economic growth and conservation of water.This study uses 19 provinces and regions along the Yangtze River’s mainstream from 2009 to 2019 as its research objects and uses a Vector Auto Regression(VAR)model to quantitatively evaluate the spatiotemporal evolution of the coupling coordination degree(CCD)between the two subsystems of WUE and STI.The findings show that:(1)Both the WUE and STI in the Yangtze River Basin showed an upward trend during the study period,but the STI effectively lagged behind the WUE;(2)The CCD of the two subsystems generally showed an upward trend,and the CCD of each province was improved to varying degrees,but the majority of regions did not develop a high-quality coordination stage;(3)The CCD of the two systems displayed apparent positive spatial autocorrelation in the spatial correlation pattern,and there were only two types:high-high(H-H)urbanization areas and low-low(L-L)urbanization areas;(4)The STI showed no obvious response to the impact of the WUE,while the WUE responded greatly to the STI,and both of them were highly dependent on themselves.Optimizing their interaction mechanisms should be the primary focus of high-quality development in the basin of the Yangtze River in the future.These results give the government an empirical basis to enhance the WUE and promote regional sustainable development. 展开更多
关键词 Water resource utilization efficiency(WUE) Scientific and technological innovation level(STI) Coupling coordination Interactive response Yangtze River Basin
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Spatio-temporal analysis of urbanization and land and water resources efficiency of oasis cities in Tarim River Basin 被引量:13
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作者 YANG Yu LIU Yi 《Journal of Geographical Sciences》 SCIE CSCD 2014年第3期509-525,共17页
This paper examines the spatial pattern of land and water resources as well as urbanization and their interactions in the Tarim River Basin, Xinjiang, China. In order to do so, we extract the data associated with effi... This paper examines the spatial pattern of land and water resources as well as urbanization and their interactions in the Tarim River Basin, Xinjiang, China. In order to do so, we extract the data associated with efficiency of land and water resources and urbanization for the years of 1995, 2000, 2005 and 2008. Specifically the paper investigates the extent to which agglomeration of population and economic activities varies geographically and inter- plays with spatial pattern of resources efficiency through computation of Global Moran's I index, Getis-Ord Gi* index and a coordinated development model. The method used provides clear evidence that urbanization, land and water resources efficiency have shown uneven spatial pattern due to oasis distribution, climate, and initial phase of urban development. Some conclusions can be drawn as follows. (1) Agglomeration and dispersion of urbanization are not consistent with those of land and water resources efficiency. (2) Evolution of the hot and cold spots of urbanization, and land and water resources efficiency, in different trajecto- ries, indicate that there are no significant interactions between them. (3) The evidence that numbers of hot and cold spots of the three factors present varying structures reveals the dominance of unequal urban development in the study area. (4) Significant differences are also found between sub-river basins in terms of the three factors, which is a reflection of the complex physical geography of the area. (5) The degree of coordinated development of cities in the Tarim River Basin is generally low in part as a reflection of difference in spatial patterns of the three factors. It is also shown that the pattern of the degree of coordinated development is relatively stable compared with evolution of hot and cold spots of the three factors. 展开更多
关键词 ESDA Tarim River Basin oasis cities land and water resources efficiency spatio-temporal variation
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Improving grain yield, nitrogen use efficiency and radiation use efficiency by dense planting, with delayed and reduced nitrogen application, in double cropping rice in South China 被引量:12
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作者 FU You-qiang ZHONG Xu-hua +9 位作者 ZENG Jia-huan LIANG Kai-ming PAN Jun-feng XIN Ying-feng LIU Yan-zhuo HU Xiang-yu PENG Bi-lin CHEN Rong-bing HU Rui HUANG Nong-rong 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2021年第2期565-580,共16页
Improving both grain yield and resource use efficiencies simultaneously is a major challenge in rice production.However,few studies have focused on integrating dense planting with delayed and reduced nitrogen applicat... Improving both grain yield and resource use efficiencies simultaneously is a major challenge in rice production.However,few studies have focused on integrating dense planting with delayed and reduced nitrogen application to enhance grain yield,nitrogen use efficiency (NUE) and radiation use efficiency (RUE) in rice (Oryza sativa L.) in the double rice cropping system in South China.A high-yielding indica hybrid rice cultivar (Yliangyou 143) was grown in field experiments in Guangxi,South China,with three cultivation managements:farmers’practice (FP),dense planting with equal N input and delayed N application (DPEN) and dense planting with reduced N input and delayed N application (DPRN).The grain yields of DPRN reached 10.6 and 9.78 t ha^(–1) in the early and late cropping seasons,respectively,which were significantly higher than the corresponding yields of FP by 23.9–29.9%.The grain yields in DPEN and DPRN were comparable.NUE in DPRN reached 65.2–72.9 kg kg^(–1),which was 61.2–74.1% higher than that in FP and 24.6–30.2% higher than that in DPEN.RUE in DPRN achieved 1.60–1.80 g MJ^(–1),which was 28.6–37.9% higher than that in FP.The productive tiller percentage in DPRN was 7.9–36.2% higher than that in DPEN.Increases in crop growth rate,leaf area duration,N uptake from panicle initiation to heading and enhancement of the apparent transformation ratio of dry weight from stems and leaf sheaths to panicles all contributed to higher grain yield and higher resource use efficiencies in DPRN.Correlation analysis revealed that the agronomic and physiological traits mentioned above were significantly and positively correlated with grain yield.Comparison trials carried out in Guangdong in 2018 and 2019 also showed that DPRN performed better than DPEN.We conclude that DPRN is a feasible approach for simultaneously increasing grain yield,NUE and RUE in the double rice cropping system in South China. 展开更多
关键词 grain yield resource use efficiencies indica rice planting density nitrogen application strategy
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Effects of deep vertical rotary tillage on the grain yield and resource use efficiency of winter wheat in the Huang-Huai-Hai Plain of China 被引量:7
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作者 WU Fen ZHAI Li-chao +6 位作者 XU Ping ZHANG Zheng-bin Elamin Hafiz BAILLO Lemessa Negasa TOLOSA Roy Njoroge KIMOTHO JIA Xiu-ling GUO Hai-qian 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2021年第2期593-605,共13页
Tillage represents an important practice that is used to dynamically regulate soil properties,and affects the grain production process and resource use efficiency of crops.The objectives of this 3-year field study car... Tillage represents an important practice that is used to dynamically regulate soil properties,and affects the grain production process and resource use efficiency of crops.The objectives of this 3-year field study carried out in the Huang-Huai-Hai(HHH) Plain of China were to compare the effects of a new deep vertical rotary tillage (DVRT) with the conventional shallow rotary tillage (CT) on soil properties,winter wheat (Triticum aestivum L.) grain yield and water and nitrogen use efficiency at different productivity levels,and to identify a comprehensive management that optimizes both grain yield and resource use efficiency in the HHH Plain.A split-plot design was adopted in field experiments in the winter wheat growing seasons of 2016–2017 (S1),2017–2018 (S2) and 2018–2019 (S3),with DVRT (conducted once in June 2016) and CT performed in the main plots.Subplots were treated with one of four targeted productivity level treatments (SH,the super high productivity level;HH,the high productivity and high efficiency productivity level;FP,the farmer productivity level;ISP,the inherent soil productivity level).The results showed that the soil bulk density was reduced and the soil water content at the anthesis stage was increased in all three years,which were due to the significant effects of DVRT.Compared with CT,grain yields,partial factor productivity of nitrogen (PFP_(N)),and water use efficiency (WUE) under DVRT were increased by 22.0,14.5 and 19.0%.Path analysis and direct correlation decomposition uncovered that grain yield variation of winter wheat was mostly contributed by the spike numbers per area under different tillage modes.General line model analysis revealed that tillage mode played a significant role on grain yield,PFP_(N) and WUE not only as a single factor,but also along with other factors(year and productivity level) in interaction manners.In addition,PFP_(N) and WUE were the highest in HH under DVRT in all three growth seasons.These results provided a theoretical basis and technical support for coordinating the high yield with high resource use efficiency of winter wheat in the resource-restricted region in the HHH Plain of China. 展开更多
关键词 winter wheat deep vertical rotary tillage resource use efficiency water use efficiency partial factor productivity of nitrogen
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Yield gap and resource utilization efficiency of three major food crops in the world——A review 被引量:2
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作者 RONG Liang-bing GONG Kai-yuan +5 位作者 DUAN Feng-ying LI Shao-kun ZHAO Ming HE Jianqiang ZHOU Wen-bin YU Qiang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2021年第2期349-362,共14页
Yield gap analysis could provide management suggestions to increase crop yields,while the understandings of resource utilization efficiency could help judge the rationality of the management.Based on more than 110 pub... Yield gap analysis could provide management suggestions to increase crop yields,while the understandings of resource utilization efficiency could help judge the rationality of the management.Based on more than 110 published papers and data from Food and Agriculture Organization (FAO,www.fao.org/faostat) and the Global Yield Gap and Water Productivity Atlas (www.yieldgap.org),this study summarized the concept,quantitative method of yield gap,yield-limiting factors,and resource utilization efficiency of the three major food crops (wheat,maize and rice).Currently,global potential yields of wheat,maize and rice were 7.7,10.4 and 8.5 t ha^(–1),respectively.However,actual yields of wheat,maize and rice were just 4.1,5.5 and 4.0 t ha^(–1),respectively.Climate,nutrients,moisture,crop varieties,planting dates,and socioeconomic conditions are the most mentioned yield-limiting factors.In terms of resource utilization,nitrogen utilization,water utilization,and radiation utilization efficiencies are still not optimal,and this review has summarized the main improvement measures.The current research focuses on quantitative potential yield and yield gap,with a rough explanation of yield-limiting factors.Subsequent research should use remote sensing data to improve the accuracy of the regional scale and use machine learning to quantify the role of yield-limiting factors in yield gaps and the impact of change crop management on resource utilization efficiency,so as to propose reasonable and effective measures to close yield gaps. 展开更多
关键词 food crops YIELD yield gap resource utilization efficiency yield-limiting factor
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Resource use efficiency, ecological intensification and sustainability of intercropping systems 被引量:5
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作者 MAO Li-li ZHANG Li-zhen +6 位作者 ZHANG Si-ping Jochem B Evers Wopke van der Werf WANG Jing-jing SUN Hong-quan SU Zhi-cheng Huub Spiertz 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2015年第8期1542-1550,共9页
The rapidly growing demand for food, feed and fuel requires further improvements of land and water management, crop productivity and resource-use efficiencies.Combined field experimentation and crop growth modelling d... The rapidly growing demand for food, feed and fuel requires further improvements of land and water management, crop productivity and resource-use efficiencies.Combined field experimentation and crop growth modelling during the past five decades made a great leap forward in the understanding of factors that determine actual and potential yields of monocrops.The research field of production ecology developed concepts to integrate biological and biophysical processes with the aim to explore crop growth potential in contrasting environments.To understand the potential of more complex systems(multi-cropping and intercropping) we need an agro-ecosystem approach that integrates knowledge derived from various disciplines: agronomy, crop physiology, crop ecology, and environmental sciences(soil, water and climate).Adaptation of cropping systems to climate change and a better tolerance to biotic and abiotic stresses by genetic improvement and by managing diverse cropping systems in a sustainable way will be of key importance in food security.To accelerate sustainable intensification of agricultural production, it is required to develop intercropping systems that are highly productive and stable under conditions with abiotic constraints(water, nutrients and weather).Strategies to achieve sustainable intensification include developing tools to evaluate crop growth potential under more extreme climatic conditions and introducing new crops and cropping systems that are more productive and robust under conditions with abiotic stress.This paper presents some examples of sustainable intensification management of intercropping systems that proved to be tolerant to extreme climate conditions. 展开更多
关键词 abiotic stress farming systems over-yielding resource use efficiency sustainability
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Comprehensive Assessment of Regional Circular Economy Development Based on Efficiency of Resource & Environment: A Case Study of Jiangsu Province 被引量:2
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作者 Zhong Taiyang Huang Xianjin +1 位作者 Li Lulu Wang Chen 《Chinese Journal of Population,Resources and Environment》 北大核心 2006年第1期54-64,共11页
In the first, the paper gave a retrospective analysis on the comprehensive assessment of circular economic development. According to the requirement of improving resource & environment efficiency, the paper design... In the first, the paper gave a retrospective analysis on the comprehensive assessment of circular economic development. According to the requirement of improving resource & environment efficiency, the paper designed an analytical framework for a comprehensive assessment of regional circular economic growth, which consists of the goal, object and technical line of the comprehensive assessment of regional circular economic development. Given that, the paper discussed the criterion for choosing the assessment index, the approaches of index's weighing determination, the means of data standardization, and the reference system of assessment index value and so on. According to the framework of regional circular economic development evaluation, die paper made a comprehensive evaluation of Jiangsu Province's circular economic development. The result shows that from temporal change, Jiangsu Province's circular economic development had different stages; from the spatial comparison, there is variance among different regions, which could be divided into different types according to the spatial variance and the relation between the development of circular economy and the aggregative index number. There was a remarkable correlation between circular economic development level and GDP or the 2nd industry GDP.Finally, the paper gives some suggestions on how to promote the development of circular economy in Jiangsu Province. 展开更多
关键词 efficiency of resource & environment comprehensive assessment of circular economic development sustainable development Jiangsu Province
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Literature Review on the Impact of Blockchain Technology on Resource Allocation Efficiency
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作者 Nuoya LIN Li'nan JIN +2 位作者 Jiaming LI Xiaofei LI Yihan XU 《Asian Agricultural Research》 2022年第6期18-20,共3页
With the rapid development of Internet technology,the importance of blockchain technology has become increasingly prominent.Faced with this situation,extensive research has been carried out at home and abroad.Through ... With the rapid development of Internet technology,the importance of blockchain technology has become increasingly prominent.Faced with this situation,extensive research has been carried out at home and abroad.Through the analysis of relevant literature on blockchain in recent years,it is found that there are many research results of blockchain technology in medical care,finance,education,etc.,but its application in the field of resource allocation efficiency is rare.From the existing studies on the influencing factors of resource allocation efficiency in China,it is found that there are significant differences in resource allocation efficiency between China and some developed countries or between various provinces and cities of China. 展开更多
关键词 Blockchain Resource allocation efficiency Influencing factors Literature review
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Machine Learning Driven Latency Optimization for Internet of Things Applications in Edge Computing 被引量:1
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作者 Uchechukwu AWADA ZHANG Jiankang +2 位作者 CHEN Sheng LI Shuangzhi YANG Shouyi 《ZTE Communications》 2023年第2期40-52,共13页
Emerging Internet of Things(IoT)applications require faster execution time and response time to achieve optimal performance.However,most IoT devices have limited or no computing capability to achieve such stringent ap... Emerging Internet of Things(IoT)applications require faster execution time and response time to achieve optimal performance.However,most IoT devices have limited or no computing capability to achieve such stringent application requirements.To this end,computation offloading in edge computing has been used for IoT systems to achieve the desired performance.Nevertheless,randomly offloading applications to any available edge without considering their resource demands,inter-application dependencies and edge resource availability may eventually result in execution delay and performance degradation.We introduce Edge-IoT,a machine learning-enabled orchestration framework in this paper,which utilizes the states of edge resources and application resource requirements to facilitate a resource-aware offloading scheme for minimizing the average latency.We further propose a variant bin-packing optimization model that co-locates applications firmly on edge resources to fully utilize available resources.Extensive experiments show the effectiveness and resource efficiency of the proposed approach. 展开更多
关键词 edge computing execution time IoT machine learning resource efficiency
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Efficient Cloud Resource Scheduling with an Optimized Throttled Load Balancing Approach
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作者 V.Dhilip Kumar J.Praveenchandar +3 位作者 Muhammad Arif Adrian Brezulianu Oana Geman Atif Ikram 《Computers, Materials & Continua》 SCIE EI 2023年第11期2179-2188,共10页
Cloud Technology is a new platform that offers on-demand computing Peripheral such as storage,processing power,and other computer system resources.It is also referred to as a system that will let the consumers utilize... Cloud Technology is a new platform that offers on-demand computing Peripheral such as storage,processing power,and other computer system resources.It is also referred to as a system that will let the consumers utilize computational resources like databases,servers,storage,and intelligence over the Internet.In a cloud network,load balancing is the process of dividing network traffic among a cluster of available servers to increase efficiency.It is also known as a server pool or server farm.When a single node is overwhelmed,balancing the workload is needed to manage unpredictable workflows.The load balancer sends the load to another free node in this case.We focus on the Balancing of workflows with the proposed approach,and we present a novel method to balance the load that manages the dynamic scheduling process.One of the preexisting load balancing techniques is considered,however it is somewhat modified to fit the scenario at hand.Depending on the experimentation’s findings,it is concluded that this suggested approach improves load balancing consistency,response time,and throughput by 6%. 展开更多
关键词 Load balancing throttled algorithm efficient resource allocation
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Strategies for Adoption of Circular Economy in the Nigeria Construction Industry
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作者 Abdullahi Idris Abdulkabir Opeyemi Bello 《Journal of Management Science & Engineering Research》 2023年第2期47-59,共13页
The concept of circular economy has gained recognition as a way to manage waste and conserve resources sustainably,and has the potential to transform the construction industry.This is particularly relevant in the cons... The concept of circular economy has gained recognition as a way to manage waste and conserve resources sustainably,and has the potential to transform the construction industry.This is particularly relevant in the construction industry due to the significant amounts of waste generated during the construction and demolition process.This study examines the perceived importance and effectiveness of strategies related to the circular economy in the construction industry.The data were collected through a survey administered to professionals in the construction sector,capturing their perceptions of various strategies.The results reveal that most strategies received high mean ratings,indicating their perceived significance.Strategies such as waste management and recycling facilities,design for disassembly,and prioritising the use of renewable and sustainable materials were highly valued by the respondents.Additionally,statistical analyses confirmed the significance of these strategies.However,some strategies received comparatively lower ratings,suggesting the need for further attention and improvement.The findings have important implications for policymakers,industry professionals,and stakeholders,guiding decision-making and resource allocation.By prioritising and implementing the identified strategies,stakeholders can drive the adoption of circular economy principles,enhance resource efficiency,and reduce waste in construction practices.Furthermore,this study lays the foundation for future research,highlighting the importance of exploring barriers to implementation,understanding synergies and trade-offs among strategies,conducting longitudinal studies to assess long-term impact,and broadening the participant pool for a more comprehensive understanding.Overall,this study contributes to the growing body of knowledge on the circular economy in the construction industry and provides valuable insights for promoting sustainability and circularity within the sector. 展开更多
关键词 Circular economy Construction industry STRATEGIES Resource efficiency SUSTAINABILITY
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An Analysis of Contemporary Copper Recycling in China 被引量:9
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作者 岳强 陆钟武 《过程工程学报》 CAS CSCD 北大核心 2006年第4期683-690,共8页
Copper consumption increased very quickly in China in recent years,which could not be met by inland copper industry.In order to achieve a sustainable development of copper industry,an analysis of copper recycling in C... Copper consumption increased very quickly in China in recent years,which could not be met by inland copper industry.In order to achieve a sustainable development of copper industry,an analysis of copper recycling in China was necessary.For the life cycle of copper products a copper-flow diagram with time factor was worked out and the contemporary copper recycling in China was analyzed,from which the following data were obtained.The average life cycle of copper products was 30 years.From 1998 to 2002,the use ratio of copper scraps in copper production,the use ratio of copper scraps in copper manufacture,the materials self-support ratio in copper production,and the materials self-support ratio in copper manufacture were 26.50%,15.49%,48.05% and 59.41%,respectively.The materials self-support ratios in copper production and manufacture declined year by year in recent years on the whole,and the latter dropped more quickly.The average index of copper ore and copper scrap from 1998 to 2002 were 0.8475 t/t and 0.0736 t/t,respectively;and copper resource efficiency was 1.1855 t/t.Some efforts should be paid to reduce copper ores consumption and promote copper scraps regeneration.Copper scraps were mostly imported from foreign countries because of shortage in recent years in China.Here the reasons related to copper scraps deficiency were also demonstrated.But we can forecast:when copper production was in a slow rise or in a steady state in China,the deficiency of copper scraps may be mitigated;when copper production was in a steady state for a very long time,copper scraps may become relatively abundant.According to the status of copper industry in China,the raw materials of copper production and manufacture have to depend on oversea markets heavily in recent years,and at the same time,the copper scraps using proportion and efficiency in copper industry should be improved. 展开更多
关键词 copper scrap copper recycling copper-flow diagram of the life cycle of copper products self-support ratio copper ore index copper scrap index copper resource efficiency
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Increased plant density and reduced N rate lead to more grain yield and higher resource utilization in summer maize 被引量:11
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作者 SHI De-yang LI Yan-hong +3 位作者 ZHANG Ji-wang LIU Peng ZHAO Bin DONG Shu-ting 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第11期2515-2528,共14页
Planting at an optimum density and supplying adequate nitrogen(N) to achieve higher yields is a common practice in crop production, especially for maize(Zea mays L.); however, excessive N fertilizer supply in maiz... Planting at an optimum density and supplying adequate nitrogen(N) to achieve higher yields is a common practice in crop production, especially for maize(Zea mays L.); however, excessive N fertilizer supply in maize production results in reduced N use efficiency(NUE) and severe negative impacts on the environment. This research was conducted to determine the effects of increased plant density and reduced N rate on grain yield, total N uptake, NUE, leaf area index(LAI), intercepted photosynthetically active radiation(IPAR), and resource use efficiency in maize. Field experiments were conducted using a popular maize hybrid Zhengdan 958(ZD958) under different combinations of plant densities and N rates to determine an effective approach for maize production with high yield and high resource use efficiency. Increasing plant density was clearly able to promote N absorption and LAI during the entire growth stage, which allowed high total N uptake and interception of radiation to achieve high dry matter accumulation(DMA), grain yield, NUE, and radiation use efficiency(RUE). However, with an increase in plant density, the demand of N increased along with grain yield. Increasing N rate can significantly increase the DMA, grain yield, LAI, IPAR, and RUE. However, this increase was non-linear and due to the input of too much N fertilizers, the efficiency of N use at NCK(320 kg ha^(–1)) was low. An appropriate reduction in N rate can therefore lead to higher NUE despite a slight loss in grain production. Taking into account both the need for high grain yield and resource use efficiency, a 30% reduction in N supply, and an increase in plant density of 3 plants m^(–2), compared to LD(5.25 plants m^(–2)), would lead to an optimal balance between yield and resource use efficiency. 展开更多
关键词 summer maize increased plant density reduced N rate N use efficiency resource use efficiency
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Plant-to-plant direct competition for belowground resource in an overlapping depletion zone 被引量:4
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作者 Amit CHAKRABORTY 《Journal of Arid Land》 SCIE 2009年第1期9-15,共7页
In response to limited availability of soil resources in basal root zone, plant extends its roots into nearby resource-rich zones to fulfill essential resource demands for survival and reproduction. This root prolifer... In response to limited availability of soil resources in basal root zone, plant extends its roots into nearby resource-rich zones to fulfill essential resource demands for survival and reproduction. This root proliferation into that enriched zones occupied by other plants constitutes interplant overlapping rooting zones and thereby the overlapping depletion zones, causing reduction in resource uptake by neighboring plants. By incorporating this mechanism into the classic resource competition model, we study interplant direct competition through their rooting system in an overlapping depletion zone. The model results indicate an extension of Tilman’s R* rule that has already been proved true when plants compete indirectly through their effect on shared resources. The results reveal that plant’s direct competitive ability (i.e., the ability to occupy an overlapping depletion zone by excluding others) can be characterized by its R*-value, where a best competitor having lowest R*-value excludes others from an overlapping zone and occupies the zone by depleting the resource level to the lowest as in its non-overlapping depletion zone. By analyzing the model, we find a suite of traits that confers R* variation among directly competing plants. This suite of traits would be a useful proxy measure for R* that do not necessarily require to establish equilibrium field monoculture—a requirement for R* measurement in the field. 展开更多
关键词 resource capture efficiency niche differentiation root proliferation resource depletion zone
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Integration of α-fairness with DEA based resource allocation model 被引量:2
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作者 Gongbing Bi Hailing Wang Jingjing Ding 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第6期1027-1036,共10页
How to allocate a resource efficiently and fairly attracts the attention of both researchers and practitioners. Data envelopment analysis(DEA) has been brought to bear on its solution. The existing literature applie... How to allocate a resource efficiently and fairly attracts the attention of both researchers and practitioners. Data envelopment analysis(DEA) has been brought to bear on its solution. The existing literature applies Gini coefficient to measure the fairness in the resource allocation process. However, the Gini coefficient is inapplicable in many applications. This paper proposes a novel centralized resource allocation model based on DEA that considers both the efficiency and the fairness. This paper adopts a notion of fairness, namely α-fairness that is well studied in welfare economics and is of practical significance. The new model integratesα-fairness with DEA to support resource allocation decisions. It aids decision makers in making a trade-off between the efficiency and the fairness. An illustrative application is used to validate the proposed approach. 展开更多
关键词 data envelopment analysis(DEA) resource alloca-tion efficiency fairness α-fairness Gini coefficient
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Hybrid Chaotic Salp Swarm with Crossover Algorithm for Underground Wireless Sensor Networks
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作者 Mariem Ayedi Walaa H.ElAshmawi Esraa Eldesouky 《Computers, Materials & Continua》 SCIE EI 2022年第8期2963-2980,共18页
Resource management in Underground Wireless Sensor Networks(UWSNs)is one of the pillars to extend the network lifetime.An intriguing design goal for such networks is to achieve balanced energy and spectral resource ut... Resource management in Underground Wireless Sensor Networks(UWSNs)is one of the pillars to extend the network lifetime.An intriguing design goal for such networks is to achieve balanced energy and spectral resource utilization.This paper focuses on optimizing the resource efficiency in UWSNs where underground relay nodes amplify and forward sensed data,received from the buried source nodes through a lossy soil medium,to the aboveground base station.A new algorithm called the Hybrid Chaotic Salp Swarm and Crossover(HCSSC)algorithm is proposed to obtain the optimal source and relay transmission powers to maximize the network resource efficiency.The proposed algorithm improves the standard Salp Swarm Algorithm(SSA)by considering a chaotic map to initialize the population along with performing the crossover technique in the position updates of salps.Through experimental results,the HCSSC algorithm proves its outstanding superiority to the standard SSA for resource efficiency optimization.Hence,the network’s lifetime is prolonged.Indeed,the proposed algorithm achieves an improvement performance of 23.6%and 20.4%for the resource efficiency and average remaining relay battery per transmission,respectively.Furthermore,simulation results demonstrate that the HCSSC algorithm proves its efficacy in the case of both equal and different node battery capacities. 展开更多
关键词 Underground wireless sensor networks resource efficiency chaotic theory crossover algorithm salp swarm algorithm
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Reducing water and nitrogen inputs combined with plastic mulched ridge-furrow irrigation improves soil water and salt status in arid saline areas,China
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作者 LI Cheng WANG Qingsong +7 位作者 LUO Shuai QUAN Hao WANG Naijiang LUO Xiaoqi ZHANG Tibin DING Dianyuan DONG Qin'ge FENG Hao 《Journal of Arid Land》 SCIE CSCD 2021年第8期761-776,共16页
Plastic mulched ridge-furrow irrigation is a useful method to improve crop productivity and decrease salt accumulation in arid saline areas.However,inappropriate irrigation and fertilizer practices may result in ecolo... Plastic mulched ridge-furrow irrigation is a useful method to improve crop productivity and decrease salt accumulation in arid saline areas.However,inappropriate irrigation and fertilizer practices may result in ecological and environmental problems.In order to improve the resource use efficiency in these areas,we investigated the effects of different irrigation amounts(400(I1),300(I2)and 200(I3)mm)and nitrogen application rates(300(F1)and 150(F2)kg N/hm^(2))on water consumption,salt variation and resource use efficiency of spring maize(Zea mays L.)in the Hetao Irrigation District(HID)of Northwest China in 2017 and 2018.Result showed that soil water contents were 0.2%-8.9%and 13.9%-18.1%lower for I2 and I3 than for I1,respectively,but that was slightly higher for F2 than for F1.Soil salt contents were 7.8%-23.5%and 48.5%-48.9%lower for I2 than for I1 and I3,but that was 1.6%-5.5%higher for F1 than for F2.Less salt leaching at the early growth stage(from sowing to six-leaf stage)and higher salt accumulation at the peak growth stage(from six-leaf to tasseling stage and from grain-filling to maturity stage)resulted in a higher soil salt content for I3 than for I1 and I2.Grain yields for I1 and I2 were significantly higher than that for I3 and irrigation water use efficiency for I2 was 14.7%-34.0%higher than that for I1.Compared with F1,F2 increased the partial factor productivity(PFP)of nitrogen fertilizer by more than 80%.PFP was not significantly different between I1F2 and I2F2,but significantly higher than those of other treatments.Considering the goal of saving water and nitrogen resources,and ensuring food security,we recommended the combination of I2F2 to ensure the sustainable development of agriculture in the HID and other similar arid saline areas. 展开更多
关键词 plastic mulched ridge-furrow irrigation crop water consumption soil salt variations resource use efficiency Hetao Irrigation District
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Can the low-carbon city pilot policy promote the upgrading of high-carbon emitting enterprises? Evidence from China
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作者 Chang’an Wang Kun Lin Xiaoqian Liu 《Chinese Journal of Population,Resources and Environment》 2022年第3期217-226,共10页
As a crucial environmental reform system to realize“carbon peaking”and“carbon neutrality”,the pilot policy of low-carbon cities(LCCs)puts pressure and challenges on high-carbon emitting enterprises(HCEEs)while pro... As a crucial environmental reform system to realize“carbon peaking”and“carbon neutrality”,the pilot policy of low-carbon cities(LCCs)puts pressure and challenges on high-carbon emitting enterprises(HCEEs)while providing opportunities for these firms to take the path of independent transformation.Employing the data of Chinese listed enterprises from 2006 to 2016 and adopting a difference-in-differences(DID)model,we evaluated the impact of LCC construction on the upgrading of HCEEs and its mechanisms.The results indicate that LCC construction enhances the upgrading of HCEEs in the pilot cities.The conclusions remain stable after a series of robustness tests.The mechanism analysis reveals that LCC construction triggers the upgrading of HCEEs by promoting resource allocation efficiency,R&D investment,and green technology innovation.The heterogeneity results indicate that this positive effect is more pronounced for HCEEs in regions with more stringent environmental law enforcement.This study also observes that the upgrading impact is more promi‐nent for state-owned enterprises,enterprises with higher bargaining power,and enterprises whose managers have a long-term vision.The above results provide directions for upgrading HCEEs and replicable evidence for cities in developing economies to fulfill the win-win target of environmental protection and economic transfor‐mation. 展开更多
关键词 Low-carbon city pilot policy High-carbon emitting enterprises Enterprise upgrading Green technology innovation Resource allocation efficiency
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Comprehensive Utility Function for Resource Allocation in Mobile Edge Computing
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作者 Zaiwar Ali Sadia Khaf +5 位作者 Ziaul Haq Abbas Ghulam Abbas Lei Jiao Amna Irshad Kyung Sup Kwak Muhammad Bilal 《Computers, Materials & Continua》 SCIE EI 2021年第2期1461-1477,共17页
In mobile edge computing(MEC),one of the important challenges is how much resources of which mobile edge server(MES)should be allocated to which user equipment(UE).The existing resource allocation schemes only conside... In mobile edge computing(MEC),one of the important challenges is how much resources of which mobile edge server(MES)should be allocated to which user equipment(UE).The existing resource allocation schemes only consider CPU as the requested resource and assume utility for MESs as either a random variable or dependent on the requested CPU only.This paper presents a novel comprehensive utility function for resource allocation in MEC.The utility function considers the heterogeneous nature of applications that a UE offloads to MES.The proposed utility function considers all important parameters,including CPU,RAM,hard disk space,required time,and distance,to calculate a more realistic utility value for MESs.Moreover,we improve upon some general algorithms,used for resource allocation in MEC and cloud computing,by considering our proposed utility function.We name the improved versions of these resource allocation schemes as comprehensive resource allocation schemes.The UE requests are modeled to represent the amount of resources requested by the UE as well as the time for which the UE has requested these resources.The utility function depends upon the UE requests and the distance between UEs and MES,and serves as a realistic means of comparison between different types of UE requests.Choosing(or selecting)an optimal MES with the optimal amount of resources to be allocated to each UE request is a challenging task.We show that MES resource allocation is sub-optimal if CPU is the only resource considered.By taking into account the other resources,i.e.,RAM,disk space,request time,and distance in the utility function,we demonstrate improvement in the resource allocation algorithms in terms of service rate,utility,and MES energy consumption. 展开更多
关键词 Cloud computing energy efficient resource allocation mobile edge computing service rate user equipment utility function
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