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Incentive-compatible and budget balanced AGV mechanism for peer-to-peer energy trading in smart grids 被引量:1
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作者 Yujia Chen Wei Pei +1 位作者 Hao Xiao Tengfei Ma 《Global Energy Interconnection》 EI CAS CSCD 2023年第1期26-35,共10页
Peer-to-peer(P2P)energy trading refers to a type of decentralized transaction,where the energy from distributed energy resources is directly traded between peers.A key challenge in peer-to-peer energy trading is desig... Peer-to-peer(P2P)energy trading refers to a type of decentralized transaction,where the energy from distributed energy resources is directly traded between peers.A key challenge in peer-to-peer energy trading is designing a safe,efficient,and transparent trading model and operating mechanism.In this study,we consider a P2P trading environment based on blockchain technology,where prosumers can submit bids or offers without knowing the reports of others.We propose an Arrow-d’Aspremont-Gerard-Varet(AGV)-based mechanism to encourage prosumers to submit their real reserve price and determine the P2P transaction price.We demonstrate that the AGV mechanism can achieve Bayesian incentive compatibility and budget balance.Kernel density estimation(KDE)is used to derive the prior distribution from the historical bid/offer information of the agents.Case studies are carried out to analyze and evaluate the proposed mechanism.Simulation results verify the effectiveness of the proposed mechanism in guiding agents to report the true reserve price while maximizing social welfare.Moreover,we discuss the advantages of budget balance for decentralized trading by comparing the Vickrey-Clarke-Groves(VCG)and AGV mechanisms. 展开更多
关键词 P2P energy trading AGV mechanism budget balance Incentive compatibility
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Ultra-low loss silicon nitride becomes even cooler
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作者 Dawn T.H.Tan Xavier X.Chia 《Light(Science & Applications)》 SCIE EI CSCD 2024年第10期1997-1999,共3页
Ultra-low loss silicon nitride realized using deuterated precursors and low thermal budgets well within backend-of-line CMOS processing may accelerate widespread proliferation of their use.
关键词 low budget NITRIDE
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Pumping-induced Well Hydraulics and Groundwater Budget in a Leaky Aquifer System with Vertical Heterogeneity in Aquitard Hydraulic Properties
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作者 ZHUANG Chao LÜChenyang +5 位作者 YAN Long LI Yabing ZHOU Zhifang WANG Jinguo DOU Zhi Walter A.ILLMAN 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第2期477-490,共14页
In groundwater hydrology,aquitard heterogeneity is often less considered compared to aquifers,despite its significant impact on groundwater hydraulics and groundwater resources evaluation.A semi-analytical solution is... In groundwater hydrology,aquitard heterogeneity is often less considered compared to aquifers,despite its significant impact on groundwater hydraulics and groundwater resources evaluation.A semi-analytical solution is derived for pumping-induced well hydraulics and groundwater budget with consideration of vertical heterogeneity in aquitard hydraulic conductivity(K)and specific storage(S_(s)).The proposed new solution is innovative in its partitioning of the aquitard into multiple homogeneous sub-layers to enable consideration of various forms of vertically heterogeneous K or S_(s).Two scenarios of analytical investigations are explored:one is the presence of aquitard interlayers with distinct K or S_(s) values,a common field-scale occurrence;another is an exponentially depth-decaying aquitard S_(s),a regional-scale phenomenon supported by statistical analysis.Analytical investigations reveal that a low-K interlayer can significantly increase aquifer drawdown and enhance aquifer/aquitard depletion;a high-S_(s) interlayer can noticeably reduce aquifer drawdown and increase aquitard depletion.Locations of low-K or high-S_(s) interlayers also significantly impact well hydraulics and groundwater budget.In the context of an exponentially depth-decaying aquitard S_(s),a larger decay exponent can enhance aquifer drawdown.When using current models with a vertically homogeneous aquitard,half the sum of the geometric and harmonic means of exponentially depth-decaying aquitard S_(s) should be used to calculate aquitard depletion and unconfined aquifer leakage. 展开更多
关键词 HYDROGEOLOGY AQUITARD vertical heterogeneity semi-analytical solution well hydraulics groundwater budget
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Optimization Analysis of Comprehensive Budget Management from the Perspective of Digital Restructuring:Taking a Water Company as an Example
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作者 Zhongjie Wang 《Proceedings of Business and Economic Studies》 2024年第4期23-31,共9页
This article takes water enterprises as the research object,exploring the organic combination of comprehensive budget management under the trend of digitalization and digital technology in the new era,as well as the p... This article takes water enterprises as the research object,exploring the organic combination of comprehensive budget management under the trend of digitalization and digital technology in the new era,as well as the process of management system reform.Introduce the current status of its budget management work,comprehensively analyze the architecture and operation mode of the current comprehensive budget management system of water enterprises,and evaluate and analyze the overall situation and shortcomings of its budget management system based on financial data such as budget formulation and execution.From the perspective of digital restructuring and upgrading of comprehensive budget management work,corresponding countermeasures are proposed to make up for the shortcomings and suggestions for the future development of the enterprise’s comprehensive budget. 展开更多
关键词 DIGITIZATION Comprehensive budget ACHIEVEMENTS Water company
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Discussion on Construction Project Cost Budget Settlement Review
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作者 Hongfeng Liu Yumin Yuan 《Journal of Architectural Research and Development》 2024年第1期43-48,共6页
Construction project cost control involves many complex contents,forming a large amount of data information.If the processing method is unreasonable,it will likely affect the cost control efficiency.Therefore,in the c... Construction project cost control involves many complex contents,forming a large amount of data information.If the processing method is unreasonable,it will likely affect the cost control efficiency.Therefore,in the current construction project management,the review of project cost budget settlement is the focus to solve the cost management problems of construction projects and promote the development of the construction industry.This article mainly analyzes the influencing factors and current situation of construction project cost budget settlement review,and based on this,it explores the project cost budget settlement review strategy to promote the healthy development of construction project cost work. 展开更多
关键词 Construction project COST budget settlement Review strategy
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Discussion on Cost Budgeting and Cost Control Strategies for Prefabricated Construction Projects
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作者 Congzi Cheng 《Journal of Architectural Research and Development》 2024年第4期17-23,共7页
In the process of China’s national economic development,the construction industry is a very important component and has a direct impact on the level of China’s economic construction.Nowadays,the development speed of... In the process of China’s national economic development,the construction industry is a very important component and has a direct impact on the level of China’s economic construction.Nowadays,the development speed of the prefabricated construction industry is constantly accelerating.To effectively ensure the economic benefits of engineering projects,it is necessary to comprehensively strengthen cost budgeting and cost control.This article analyzes the cost budget of prefabricated construction projects,introduces the application advantages of prefabricated construction,and proposes specific cost budgeting and cost control measures,hoping to provide some reference for relevant researchers. 展开更多
关键词 Prefabricated building Engineering cost budget Cost control
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Link Budget and Enhanced Communication Distance for Ambient Internet of Things
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作者 YANG Yibing LIU Ming +2 位作者 XU Rongtao WANG Gongpu GONG Wei 《ZTE Communications》 2024年第1期16-23,共8页
Backscatter communications will play an important role in connecting everything for beyond 5G(B5G)and 6G systems.One open challenge for backscatter communications is that the signals suffer a round-trip path loss so t... Backscatter communications will play an important role in connecting everything for beyond 5G(B5G)and 6G systems.One open challenge for backscatter communications is that the signals suffer a round-trip path loss so that the communication distance is short.In this paper,we first calculate the communication distance upper bounds for both uplink and downlink by measuring the tag sensitivity and reflection coefficient.It is found that the activation voltage of the envelope detection diode of the downlink tag is the main factor limiting the back-scatter communication distance.Based on this analysis,we then propose to implement a low-noise amplifier(LNA)module before the envelope detection at the tag to enhance the incident signal strength.Our experimental results on the hardware platform show that our method can increase the downlink communication range by nearly 20 m. 展开更多
关键词 ambient IoT(AIoT) B5G backscatter communication link budget low-noise amplifier(LNA) Release 19 tag chip sensitivity upper bounds
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Analysis of Hospital Budget Management Control Based on Smart Hospital
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作者 Yuqi Chen 《Journal of Clinical and Nursing Research》 2024年第5期169-173,共5页
Hospitals are crucial healthcare facilities where patients seek treatment,and effective budget management within hospitals significantly impacts their operational efficiency and financial performance.In the age of inf... Hospitals are crucial healthcare facilities where patients seek treatment,and effective budget management within hospitals significantly impacts their operational efficiency and financial performance.In the age of information technology and advanced healthcare solutions,the emergence of smart hospitals represents a new trend in the medical industry’s evolution.Leveraging modern information technology can enhance the development of hospital IT systems and drive budget management toward greater intelligence.This paper begins by analyzing the influence of smart hospitals on hospital budget control.It then examines the current state of budget management control within smart hospitals.Finally,it proposes several strategies for budget management control in smart hospitals,aiming to provide guidance for relevant stakeholders. 展开更多
关键词 Smart hospital Hospital management budget management Financial control Control strategies
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Fund budget model for multipurpose transit smart card systems
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作者 张宁 钱振东 +1 位作者 陈恺 杨利强 《Journal of Southeast University(English Edition)》 EI CAS 2008年第1期95-98,共4页
The fund budget of multipurpose transit smart card systems is studied by stochastic programming to assign limited funds to different applications reasonably. Under the constraints of a gross fund, models of chance-con... The fund budget of multipurpose transit smart card systems is studied by stochastic programming to assign limited funds to different applications reasonably. Under the constraints of a gross fund, models of chance-constrained and dependentchance for the fund budget of multipurpose transit smart card systems are established with application scale and social demand as random variables, respectively aiming to maximize earnings and satisfy the service requirements the furthest; and the genetic algorithm based on stochastic simulation is adopted for model solution. The calculation results show that the fund budget differs greatly with different system objectives which can cause the systems to have distinct expansibilities, and the application scales of some applications may not satisfy user demands with limited funds. The analysis results indicate that the forecast of application scales and application future demands should be done first, and then the system objective is determined according to the system mission, which can help reduce the risks of fund budgets. 展开更多
关键词 multipurpose transit smart card systems fund budgeting stochastic programming genetic algorithm
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Comparative Analysis of Agricultural Budget in the European Union and China
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作者 傅钰 李广 《Agricultural Science & Technology》 CAS 2017年第3期553-555,564,共4页
With rapid development, the agriculture in the European Union (EU) is al- ways in the wodd's leading ranks, and with relatively complete systems, the devel- opment of agricultural budget in EU also has achieved a l... With rapid development, the agriculture in the European Union (EU) is al- ways in the wodd's leading ranks, and with relatively complete systems, the devel- opment of agricultural budget in EU also has achieved a lot. China's agricultural budget has been improved gradually with the rapid economic development, but also has exposed a series of problems. Therefore, countermeasures and suggestions are proposed through the comparative analysis on the agriculture budgeting, budget en- forcement, budget supervision between Europe and China. 展开更多
关键词 Agricultural budget expenditure Common agricultural policy budgetmanagement
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Nitrogen Budget in Recirculating Aquaculture and Water Exchange Systems for Culturing Litopenaeus vannamei 被引量:6
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作者 CHEN Zhao GE Hongxing +3 位作者 CHANG Zhiqiang SONG Xiefa ZHAO Fazhen LI Jian 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第4期905-912,共8页
In order to investigate the culture characteristics of two indoor intensive Litopenaeus vannamei farming modes, recirculating aquaculture system(RAS) and water exchange system(WES), this study was carried out to analy... In order to investigate the culture characteristics of two indoor intensive Litopenaeus vannamei farming modes, recirculating aquaculture system(RAS) and water exchange system(WES), this study was carried out to analyze the water quality and nitrogen budget including various forms of nitrogen, microorganism and chlorophyll-a. Nitrogen budget was calculated based on feed input, shrimp harvest, water quality and renewal rate, and collection of bottom mud. Input nitrogen retained in shrimp was 23.58% and 19.10% respectively for WES and RAS, and most of nitrogen waste retained in water and bottom mud. In addition, most of nitrogen in the water of WES was TAN(21.32%) and nitrite(15.30%), while in RAS was nitrate(25.97%), which means that more than 76% of ammonia and nitrite were removed. The effect of microalgae in RAS and WES was negligible. However, bacteria played a great role in the culture system considering the highest cultivable cultivable bacterial populations in RAS and WES were 1.03×10^(10) cfu mL^(-1) and 2.92×10~9 cfu mL^(-1), respectively. Meanwhile the proportion of bacteria in nitrogen budget was 29.61% and 24.61% in RAS and WES, respectively. RAS and WES could realize shrimp high stocking culture with water consuming rate of 1.25 m^3 per kg shrimp and 3.89 m^3 per kg shrimp, and power consuming rates of 3.60 kwh per kg shrimp and 2.51 kwh per kg shrimp, respectively. This study revealed the aquatic environment and nitrogen budget of intensive shrimp farming in detail, which provided the scientific basis for improving the industrial shrimp farming. 展开更多
关键词 RAS SHRIMP water quality nitrogen budget MICROORGANISM
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Surface Heat Budget and Solar Radiation Allocation at a Melt Pond During Summer in the Central Arctic Ocean 被引量:5
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作者 ZHANG Shugang ZHAO Jinping +1 位作者 SHI Jiuxin JIAO Yutian 《Journal of Ocean University of China》 SCIE CAS 2014年第1期45-50,共6页
The heat budget of a melt pond surface and the solar radiation allocation at the melt pond are studied using the 2010 Chinese National Arctic Research Expedition data collected in the central Arctic. Temperature at a ... The heat budget of a melt pond surface and the solar radiation allocation at the melt pond are studied using the 2010 Chinese National Arctic Research Expedition data collected in the central Arctic. Temperature at a melt pond surface is proportional to the air temperature above it. However, the linear relationship between the two varies, depending on whether the air temperature is higher or lower than 0℃. The melt pond surface temperature is strongly influenced by the air temperature when the latter is lower than 0℃. Both net longwave radiation and turbulent heat flux can cause energy loss in a melt pond, but the loss by the latter is larger than that by the former. The turbulent heat flux is more than twice the net longwave radiation when the air temperature is lower than 0℃. More than 50% of the radiation energy entering the pond surface is absorbed by pond water. Very thin ice sheet on the pond surface(black ice) appears when the air temperature is lower than 0℃; on the other hand, only a small percentage(5.5%) of net longwave in the solar radiation is absorbed by such a thin ice sheet. 展开更多
关键词 heat budget MElt POND solar radiation ARCTIC
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Nitrogen and Phosphorus Budget of a Polyculture System of Sea Cucumber(Apostichopus japonicus), Jellyfish(Rhopilema esculenta) and Shrimp(Fenneropenaeus chinensis) 被引量:3
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作者 LI Junwei DONG Shuanglin +1 位作者 GAO Qinfeng ZHU Changbo 《Journal of Ocean University of China》 SCIE CAS 2014年第3期503-508,共6页
The nitrogen(N) and phosphorus(P) budget and the ecological efficiency of a polyculture system of sea cucumber(Apostichopus japonicus), jellyfish(Rhopilema esculenta) and shrimp(Fenneropenaeus chinensis) were studied ... The nitrogen(N) and phosphorus(P) budget and the ecological efficiency of a polyculture system of sea cucumber(Apostichopus japonicus), jellyfish(Rhopilema esculenta) and shrimp(Fenneropenaeus chinensis) were studied in a cofferdam, 120.2 ha in size. The nutrients were supplied by spring tide inflow. In total, 139600 kg N yr-1 and 9730 kg P yr-1 input to the system; while 118900 kg N yr-1 and 2840 kg P yr-1 outflowed from the system concurrently, thus the outflow was 85.7%(N) and 29.2%(P) of inflow. The production of N and P was 889.5 kg yr-1 and 49.28 kg yr-1(sea cucumber) and 204 kg yr-1 and 18.03 kg yr-1(jellyfish and shrimp), respectively. The utilization rate of N and P by polycultured animals was 7.8‰ and 6.9‰, respectively, 21.9% and 38% higher than that of monocultured sea cucumber. Our results indicated that the polyculture system was an efficient culture system of animals and a remediation system of coastal environment as well; it scavenged 14.3% and 70.8% of N and P, respectively. Such an ecological efficiency may be improved further by increasing either the stocking density or the size of sea cucumber or both. 展开更多
关键词 POLYCUltURE nitrogen budget phosphorus budget Apostichopus japonicus Rhopilema esculenta Fenneropenaeus chinensis
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COMPARATIVE STUDIES ON NITROGEN BUDGETS OF CLOSED SHRIMP POLYCULTURE SYSTEMS 被引量:3
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作者 齐振雄 李德尚 +1 位作者 张曼平 董双林 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2001年第3期233-242,共10页
April to October, 1997 comparative studies on the nitrogen budgets of closed shrimp polyculture systems showed that, in all the studied polyculture systems, nitrogen from feeds and fertilizers were the main input item... April to October, 1997 comparative studies on the nitrogen budgets of closed shrimp polyculture systems showed that, in all the studied polyculture systems, nitrogen from feeds and fertilizers were the main input items, which comprised 70.7%-83.9% of the total input nitrogen, 3.2%-7.4% of which was provided by nitrogen fixation. It was in monoculture enclosures (Y 4, Y 11 and Y 12) that the percentage reached the maximum value. The output nitrogen in harvested products comprised 10.8%-24.6% of total input nitrogen, and the highest percentage, 24.6%, was found in shrimp fish tagelus polyculture systems. In shrimp monoculture and shrimp fish polyculture systems, they were 19.1% and 21.9%, respectively. The nitrogen utilization efficiency was different and varied from 12.2% to 20.1%. The highest, 20.1%, was found in shrimp fish tagelus polyculture systems, and the average of 20.0% was found in shrimp tagelus polyculture systems. The lowest, 12.2%, was found in shrimp monoculture systems. All the nitrogen utilization efficiencies in shrimp fish systems or shrimp scallop systems seemed to be higher than that of the monoculture system, but they showed little statistical difference. The main outputs of nitrogen were found in sediment mud, and comprised 48.2%-60.8% of the total input, the lowest percentage was found in shrimp fish tagelus polyculture systems, and the highest percentage in shrimp scallop systems. During the experiment, nitrogen lost through denitrification and ammonia volatilization comprised 1.9%-6.2%, averaged 2.8%, of the total input, and the loss through seepage comprised 5.9%-8.9% of the total. The estimated nitrogen attached to the enclosure wall comprised 3.7%-13.3% of the total, and was highest in shrimp monoculture systems. Compared with the classic shrimp farming industry, the closed shrimp polyculture systems may improve the nitrogen utilization efficiency, and hence reduce the environmental impacts on coastal waters. The nitrogen discharging rates for all the studied polyculture systems ranged from 3.0% to 6.0% of total input nitrogen. 展开更多
关键词 nitrogen budget shrimp culture polyculture system
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Influence of stocking density on growth, body composition and energy budget of Atlantic salmon Salmo salar L. in recirculating aquaculture systems 被引量:5
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作者 刘宝良 刘鹰 +3 位作者 刘子毅 仇登高 孙国祥 李贤 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第5期982-990,共9页
Atlantic salmon Salmo salar were reared at four stocking densities--high density D1 (final density -39 kg/m^3), medium densities DE (-29 kg/m^3) and D3 (~19 kg/m^3), and low density D4 (-12 kg/m^3)- for 40 day... Atlantic salmon Salmo salar were reared at four stocking densities--high density D1 (final density -39 kg/m^3), medium densities DE (-29 kg/m^3) and D3 (~19 kg/m^3), and low density D4 (-12 kg/m^3)- for 40 days to investigate the effect of stocking density on their growth performance, body composition and energy budgets. Stocking density did not significantly affect specific growth rate in terms of weight (SGRw) but did affect specific growth rate in terms of energy (SGRe). Stocking density significantly influenced the ration level (RLw and RLe), feed conversion ratio (FCRw and FCRe) and apparent digestibility rate (ADR). Ration level and FCRw tended to increase with increasing density. Fish at the highest density D~ and lowest density D4 showed lower FCRe and higher ADR than at medium densities. Stocking density significantly affected protein and energy contents of the body but did not affect its moisture, lipid, or ash contents. The expenditure of energy for metabolism in the low-density and high-density groups was lower than that in the medium-density groups. Stocking density affected energy utilization from the feces but had no effect on excretion rate. The greater energy allocation to growth at high density and low density may be attributed to reduced metabolic rate and increased apparent digestibility rate. These findings provide information that will assist selection of suitable stocking densities in the Atlantic-salmon-farming industry. 展开更多
关键词 stocking density Atlantic salmon GROWTH body composition energy budget recirculatingaquaculture system
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Are diurnal time-budgets and activity patterns density-dependent in the Shelduck (Tadorna tadorna) wintering in Algeria? An analysis across multiple temporal scales 被引量:1
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作者 Djamel Bensizerara Haroun Chenchouni 《Avian Research》 CSCD 2019年第2期171-185,共15页
Background: The Shelduck (Tadorna tadorna) is a characteristic waterbird species of inland wetlands in northeastern Algeria. Its wintering behavior in relation to changes of local abundances and foraging group density... Background: The Shelduck (Tadorna tadorna) is a characteristic waterbird species of inland wetlands in northeastern Algeria. Its wintering behavior in relation to changes of local abundances and foraging group density is poorly known. Objectives: This study aims at monitoring patterns of diurnal activities and the variation of behavioral time-budgets in relation to numbers of wintering Shelducks. We investigate temporal variations of diurnal activities across multipletime scales and consider their interrelationships. Methods: Assessments of local population abundance were weekly surveyed during two wintering seasons (2010– 2012), whereas diurnal activities (feeding, sleeping, swimming, preening, loafing, flying, courtship, and antagonism) were studied three times a month during seven hours (08:00–16:00) using the Scan method. Time budget variations of each behavioral activity were tested using nested ANOVAs following multiple time scales. Generalized linear mixedeffects models (GLMM) tested whether variations in diurnal activities were density-dependent. Results: During the wintering season, Shelduck’s numbers followed a bell-shaped trend, which indicated that the species was typically a wintering migrant in Sabkha Djendli. The first individuals arrived onsite in October–November then numbers reached a peak in January (up to 2400 individuals in 2012) with steady density during December–February, afterward individuals left the site progressively until late April when the site is deserted. During both wintering seasons, diurnal activities were dominated by feeding (60%), followed by sleeping (12%) then swimming and preening with 9% and 8%, respectively. The rest of the activities (loafing, flying, courtship and antagonistic behaviors) had low proportions of time budget. ANOVAs showed that activity time budgets varied significantly following multiple time scales (year, season, month, day, semi-hour). Time budgets of diurnal activities during each wintering season were significantly interrelated. Correlations patterns between the two seasons were similar. GLMMs revealed that the variations of diurnal activities were not density-dependent, except for preening and swimming. Conclusion: During the wintering season, habitats of Sabkha Djendli are important for waterbirds, including the Shelduck that used the lake mainly for food-foraging and resting. The 2400 individuals censused in mid-winter are important locally and at the North African scale. This stresses the need to strengthen the protection status of this wetland and mitigate degradation sources that threaten wintering waterfowl. 展开更多
关键词 ANATIDAE Multi-temporal scales North African wetlands TIME budget WATERBIRD CENSUS
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Using ^(137)Cs Tracing Methods to Estimate Soil Redistribution Rates and to Construct a Sediment Budget for a Small Agricultural Catchment in the Three Gorges Reservoir Region,China 被引量:7
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作者 JU Li WEN An-bang +2 位作者 LONG Yi YAN Dong-chun GUO Jin 《Journal of Mountain Science》 SCIE CSCD 2013年第3期428-436,共9页
Soil erosion and associated off-site sedimentation are threatening the sustainable use of the Three Gorges Dam. To initiate management intervention to reduce sediment yields, there is an increasing need for reliable i... Soil erosion and associated off-site sedimentation are threatening the sustainable use of the Three Gorges Dam. To initiate management intervention to reduce sediment yields, there is an increasing need for reliable information on soil erosion in the Three Gorges Reservoir Region (TGRR). The purpose of this study is to use 137Cs tracing methods to construct a sediment budget for a small agricultural catchment in the TGRR. Cores were taken from a pond and from paddy fields, for laTCs measurements. The results show that the average sedimentation rate in the pond since 1963 is 1.50 g cm-2 yr-1 and the corresponding amount of sediment deposited is 1,553 t. The surface erosion rate for the sloping cultivated lands and the sedimentation rate in the paddy fields were estimated to be 3,770 t km-2 yr-1 and 2,600 t km-2 yr^1 respectively. Based on the estimated erosion and deposition rates, and the area of each unit, the post 197o sediment budget for the catchment has been constructed. A sediment delivery ratio of 0.5 has been estimated for the past 42 years. The data indicate that the sloping cultivated lands are the primary sediment source areas, and that the paddy fields are deposition zones. The typical land use pattern (with the upper parts characterized by sloping cultivated land and the lower parts by paddy fields) plays an important role in reducing sediment yield from agricultural catchments in the TGRR. A 137Cs profile for the sediment deposited in a pond is shownto provide an effective means of estimating the land surface erosion rate in the upstream catchment. 展开更多
关键词 Pond deposition Soil erosion rate Sediment budget 137Cs Sediment delivery ratio Three Gorges Reservoir Region
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Evaluation of phosphorus and nitrogen balances as an indicator for the impact of agriculture on environment: A comparison of a case study from Poland and Mississippi US 被引量:1
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作者 Renata Gaj Nacer Bellaloui 《Agricultural Sciences》 2012年第2期317-329,共13页
The objective of this research was to quantify the changes of nitrogen (N) and phosphorus (P) balances in Poland and Mississippi (MS), USA. Nutrient balances were calculated as difference between input and output in t... The objective of this research was to quantify the changes of nitrogen (N) and phosphorus (P) balances in Poland and Mississippi (MS), USA. Nutrient balances were calculated as difference between input and output in the agricultural system according to Organisation for Economic Cooperation and Development (OECD) methodology. A positive nutrient balance means that a potential environmental problem may result from that nutrient;a negative nutrient balance means there is a potential yield loss. The N and P soil surface balances for Poland and MS were calculated for the year 1998 through 2008. The results showed that both MS and Poland had positive N and P balances, indicating that there was a surplus of N and P. The average balance for N was 48 kg·ha-1 in Poland and 102 kg·ha-1 in MS. For P, it was 3 kg·ha-1 in Poland and 19 kg P kg·ha-1 in MS per cultivated area. This research demonstrated that the nutrient balance of N or P depended on the efficient use of each nutrient and type and source of fertilizer used. This research is significant for N and P fertilizer management and their impact on agriculture production and environment health. 展开更多
关键词 Nitrogen PHOSPHORUS NUTRIENT Efficiency NUTRIENT AVAILABILITY NUTRIENT budget
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Energy Budget over Seasonal Snow Surface at an Open Site and Beneath Forest Canopy Openness during the Snowmelt Period in Western Tianshan Mountains,China 被引量:1
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作者 LU Heng WEI Wen-shou +2 位作者 LIU Mingzhe HAN Xi HONG Wen 《Journal of Mountain Science》 SCIE CSCD 2015年第2期298-312,共15页
In this study, meteorological factors and snowmelt rate at an open site on sunny slope(OPS) and beneath forest canopy openness on shady slope(BFC) were measured using an automatic weather station and snow lysimeter du... In this study, meteorological factors and snowmelt rate at an open site on sunny slope(OPS) and beneath forest canopy openness on shady slope(BFC) were measured using an automatic weather station and snow lysimeter during the snowmelt period in 2009, 2010 and 2013. The energy budget over snow surface was calculated according to these meteorological datasets. The analysis results indicated that the net shortwave radiation(K) and sensible heat flux(H) were energy sources, and the latent heat flux(LVE) was energy sinks of snow surfaces at all sites. The net longwave radiation(L) was energy sink at OPS and 80% BFC, but energy source at 20% BFC. The gain of K, H, and the loss of LVE at BFC were obviously lower than those at OPS. The L was the maximum difference of energy budget between snow surface at BFC and OPS. In warm and wet years, the most important factor of the energy budget variation at OPS was air humidity and the second mostimportant factor was air temperature. However, the ground surface temperature on the sunny slope was the most important factor for L and energy budget at BFC. With the increases in forest canopy openness and the slope of adjacent terrains, the influences of ground surface temperature on the sunny slope on L and the energy budget over snow surface at BFC increased, especially when the snow cover on the sunny slope melts completely. 展开更多
关键词 Energy budget Seasonal snow Snowmelt period Tianshan Mountains
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Production of Pacific White Shrimp Polycultured with Swimming Crab at Different Densities, and Nutrient Budget in the Enclosure System 被引量:1
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作者 ZHOU Yangen BAO Weiyang +4 位作者 SU Yuepeng HUANG Ming WANG Xingqiang YAN Binlun MA Shen 《Journal of Ocean University of China》 SCIE CAS CSCD 2022年第1期171-178,共8页
This study was to evaluate the effect of stocking densities on the nitrogen and phosphorus budgets for a polyculture of the crab Portunus trituberculatus and the Pacific white shrimp Litopenaeus vannamei.The shrimps(i... This study was to evaluate the effect of stocking densities on the nitrogen and phosphorus budgets for a polyculture of the crab Portunus trituberculatus and the Pacific white shrimp Litopenaeus vannamei.The shrimps(initial weight,0.012 g)were cultured at a density of 45 shrimp m^(-2),and juvenile crabs(initial weight,0.024 g)were cultured at five densities of 0,3,6,9,and 12 crabs m^(-2).The treatments were grouped as C0S45,C3S45,C6S45,C9S45,and C12S45,respectively.Water quality parameters,growth of shrimp and crabs,and nitrogen and phosphorus budget were measured.The results indicated that the shrimp performances in polyculture treatments C3S45 and C6S45 were superior to those in the crab-free treatment(C0S45).The crab in treatments C3S45 and C6S45 exhibited a significantly higher final mean weight and carapace width/length than those in treatments C9S45 and C12S45.The final size and survival of crabs had a negative correlation with the increasing crab stocking density.The contents of total phos-phorus and total nitrogen and the comprehensive contamination index values were higher in the C9S45 and C12S45 treatments than in the other treatments.The conversion ratios of nitrogen for crab and shrimp growth in treatment C3S45 were significantly higher than those in the crab-free treatment.These findings indicate that polyculturing shrimp with crabs at suitable densities can improve productivity,profitability,nutrient utilization,and the environmental quality.From the 60-day treatments,the optimal culture densi-ties were 3-6 crabs m^(-2) and 45 shrimps m^(-2). 展开更多
关键词 growth metrics crustacean polyculture nutrient budget sediment quality water quality
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