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Phosphorus accumulation and eutrophication in feed-supply freshwater fishponds

Journal of Environmental Sciences 2006年第4期18卷 816-821页

作者： ZHANG Ming-kui fang Li-ping Institute of Soil and Water Resources and Environmental Science College of Natural Resource and Environmental Sciences Zhejiang UniversityHangzhou 310029 China

The rapid growth and intensification of freshwater fishery can cause imbalances between phosphorus （P） input in feed and its output in produce. This aquaculture can result in enriching exogenous P in fishponds and, consequently, accelerates the process of eutrophication. To assess relations among input, accumulation, release of P and as a consequence degrading water quality in terms of chlorophyll-a （Chl-a） in freshwater fishponds, fourteen fishponds with feed supply, nine fishponds without feed supply, and five nonfish ponds in Shaoxing Plain, southeast China were selected for comparing P accumulation in their waters and surface sediments. Surface sediment samples were collected from each pond to evaluate their total P, water soluble P, Olsen P, algal available P, and P fractions. Water samples were also collected from the ponds to measure concentrations of dissolved P and Chl-a. Total P in the sediments ranged from 0.88 to 1.73 g/kg in the fishponds with feed supply, that in the non-fish ponds ranged from 0.47 to 0.86 g/kg. Organic P, accounted for 23% to 60% of total P in the sediments, was an important P fraction and increased linearly with increasing organic matter. Long-term application of feeds resulted in increased P availability in the bottom sediments and degradation of water quality in the freshwater fishponds. Compared with non-fish ponds, sediments from the feed-supplied fishponds contained considerably higher Olsen P, algal available P, and water soluble P. Higher proportions of the labile P （NH4Cl-P） and potentially labile P （NaOH-IP） were also found in the sediments from the fishponds. High solubility of P in the sediments resulted in elevation of P and chlorophyll-a concentration in the pond water. The dissolved P concentration in the pond water increased in the order of non-fish ponds （12μg/L）〈 fishponds without feed supply （24 μg/L）〈 fishponds with feed supply （66 μg/L）. Linear correlations between concentrations of total P, Olsen-P, algal avail

关键词： eutrophication freshwater fishery phosphorus fraction water quality

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Novel Incentive Scheme to Motivate Flexible Customers for Phase Balancing

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CSEE Journal of Power and Energy Systems 2022年第4期8卷 1048-1059页

作者： Lurui fang Kang Ma Furong Li fei Xue Xi'an Jiaotong-liverpool University Suzhou 215123Chin University of Bath BathUK

Phase imbalance is a significant and widespread problem in low voltage(LV,415V)*** paper develops a novel incentive scheme that encourages flexible customers to engage in phase *** the technical side,this incentive scheme is based on a centralized control algorithm utilizing the inherent fexibility of customers'AC/DC converters to achieve phase balancing at the substation side of LV *** the incentive side,first,this paper calculates the benefits from phase *** then defines a rebalancing contribution index that quantifies the flexible customer's contribution to addressing the predominant imbalance-induced consequence,e.g,capacity wastes,and energy *** to the contribution indices and the benefits,the incentive scheme rewards flexible customers correspondingly and guides them to prioritize the predominant consequence of phase *** studies demonstrate that:1)the remunerations paid to the flexible customers primarily depends on their contributions to addressing the predominant imbalance-induced consequences for the network in question;2)the incentive scheme does not discriminate against small/medium-sized flexible customers who are dedicated to phase balancing,thus promoting inclusiveness.

关键词： Competition-based contribution index low voltage incentive scheme phase imbalance power distribution

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Higher-order electroelastic modelling of piezoelectric cylindrical nanoshell on elastic matrix

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Defence Technology（防务技术） 2022年第5期18卷 781-796页

作者： Xiao-ping Huang Peng-fei Hu Mohammad Arefi College of Mechanical and Electrical Engineering Nanning UniversityNanning530000GuangxiChina School of Materials Science and Engineering Luoyang Institute of TechnologyLuoyang471023HenanChina Department of Solid Mechanics Faculty of Mechanical EngineeringUniversity of KashanKashan87317-51167Iran

This paper develops electro-elastic relations of functionally graded cylindrical nanoshell integrated with intelligent layers subjected to multi-physics loads resting on elastic *** piezoelectric layers are actuated with external applied *** nanocore is assumed in-homogeneous in which the material properties are changed continuously and gradually along radial ***-order shear deformation theory is used for the description of kinematic relations and electric potential distribution is assumed as combination of a linear function along thickness direction to show applied voltage and a longitudinal ***-elastic size-dependent constitutive relations are developed based on nonlocal elasticity theory and generalized Hooke’s *** principle of virtual work is used to derive governing equations in terms of four functions along the axial and the radial directions and longitudinal electric potential *** numerical results including radial and longitudinal displacements are presented in terms of basic input parameters of the integrated cylindrical nanoshell such as initial electric potential,small scale parameter,length to radius ratio and two parameters of *** is concluded that both displacements are increased with an increase in small-scale parameter and a decrease in applied electric potential.

关键词： Higher-order shear deformation theory Electro-elastic bending Functionally graded materials Size-dependent analysis Nonlocal parameter Cylindrical nano shell

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Entanglement in Three-Atom Tavis-Cummings Model Induced by a Thermal Field

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Communications in Theoretical Physics 2005年第3期43卷 427-431页

作者： CAIJin-fang LIUHui-ping DepartmentofPhysics BeijingInstituteofTechnologyBeijing100081China

The explicit form of the evolution operator for the three-atom Tavis-Cummings model is given. The atoms can be entangled through their interaction with a thermal field. The degree of entanglement depends on the mean p... 详细信息

关键词： entanglement evolution operator Tavis-Cummings model thermal field

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Effect of microscopic pore structures on ultrasonic velocity in tight sandstone with different fluid saturation

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Petroleum Science 2022年第6期19卷 2683-2694页

作者： Jian-Yong Xie Jun-Jie Zhang Wei Xiang Yan-ping fang Ya-Juan Xue Jun-Xing Cao Ren-fei Tian State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of Technology(CDUT)Geophysical InstituteChengduSichuan610059China Oilfield Technology Division China National Offshore Oilfield Services Co.ZhanjiangGuangdong524000China School of Communication Engineering Chengdu University of Information TechnologyChengduSichuan610225China State Key Laboratory of Natural Gas Hydrate Beijing100028China

Microcosmic details of pore structure are the essential factors affecting the elastic properties of tight sandstone reservoirs,while the relationships in between are still incompletely clear due to the fact that quantitative or semi-quantitative experiments are hard to ***,three sets of tight sandstone samples from the Junggar Basin are selected elaborately based on casting thin sections,XRD detection,and petro-physical measurement,and each set is characterized by a single varied microcosmic factor(pore connectedness,pore type,and grain size)of the pore *** ultrasonic pulse transmission technique is conducted to study the response of elastic properties to the varied microcosmic details of pore structure in the situation of different pore fluid(gas,brine,and oil)saturation and confining *** show samples with less connectedness,inter-granular dominant pores,and smaller grain size showed greater velocities in normal *** more sensitive to the variations of pore type,while Vsis more sensitive to the variations of grain *** with better connectedness at fluid saturation(oil or brine)show greater sensitivity to the confining pressure than those with gas saturation with a growth rate of 6.9%-11.9%,and the sensitivity is more likely controlled by *** pore types(inter-granular or intra-granular)can be distinguished by the sensitivity of velocities to the variation of pore fluid at high confining pressure(>60 MPa).The samples with small grain sizes tend to be more sensitive to the variations of confining *** this knowledge,we can semi-quantitatively distinguish the complex pore structures with different fluids by the variation of elastic properties,which can help improve the precision of seismic reservoir prediction for tight sandstone reservoirs.

关键词： Tight sandstone Pore structure Casting thin section Ultrasonic measurement

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A Survey of Recent Results in Quantized and Event-based Nonlinear Control

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International Journal of Automation and computing 2015年第5期12卷 455-466页

作者： Zhong-ping Jiang Teng-fei Liu Polytechnic School of Engineering New York University State Key Laboratory of Synthetical Automation for Process Industries Northeastern University

Constructive nonlinear control design has undergone rapid and significant progress over the last three decades. In this paper, a review of recent results in this important field is presented with a focus on interdisciplinary topics at the interface of control,computing and communications. In particular, it is shown that the nonlinear small-gain theory provides a unified framework for solving problems of quantized feedback stabilization and event-triggered control for nonlinear systems. Some open questions in quantized and networked nonlinear control systems are discussed.

关键词： Nonlinear systems nonlinear control quantized cont

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Joint optimization traffic signal control for an urban arterial road

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Applied Mathematics(A Journal of Chinese Universities) 2009年第2期24卷 135-143页

作者： LI Yin-fei CHEN Shu-ping Dept. of Math. Zhejiang Univ. Hangzhou 310027 China College of Statist. & Math. Zhejiang Gongshang Univ. Hangzhou 310018 China Guizhou Univ. Guiyang 550025 China

This paper considers the optimal traffic signal setting for an urban arterial road. By introducing the concepts of synchronization rate and non-synchronization degree, a mathematical model is constructed and an optimization problem is posed. Then, a new iterative algorithm is developed to solve this optimal traffic control signal setting problem. Convergence properties for this iterative algorithm are established. Finally, a numerical example is solved to illustrate the effectiveness of the method.

关键词： urban traffic network intersection traffic signal setting synchronism optimization

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A new family of covariate-adjusted response adaptive designs and their properties

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Applied Mathematics(A Journal of Chinese Universities) 2009年第1期24卷 1-13页

作者： ZHANG Li-Xin HU fei-fang Institute of Statist. and Dept. of Math. Zhejiang Univ. Hongzhou 310027 China Dept. of Statist. Univ. of Virginia Charlottesville VA 22904-4135 USA

It is often important to incorporate covariate information in the design of clinical trials. In literature there are many designs of using stratification and covariate-adaptive randomization to balance certain known covariate. Recently, some covariate-adjusted response-adaptive （CARA） designs have been proposed and their asymptotic properties have been studied （Ann. Statist. 2007）. However, these CARA designs usually have high variabilities. In this paper, a new family of covariate-adjusted response-adaptive （CARA） designs is presented. It is shown that the new designs have less variables and therefore are more efficient.

关键词： adaptive design covariate efficiency asymptotic variability

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Production of N-acetylglucosamine with Vibrio alginolyticus FA2,an emerging platform for economical unsterile open fermentation

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Synthetic and Systems Biotechnology 2023年第3期8卷 546-554页

作者： Yuan Peng ping Xu fei Tao State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental Sciencesand School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghaiPeople’s Republic of China

Members of the Vibrionaceae family are predominantly fast-growing and halophilic microorganisms that have captured the attention of researchers owing to their potential applications in rapid *** them,Vibrio alginolyticus FA2 is a particularly noteworthy halophilic bacterium that exhibits superior growth *** has the potential to serve as a biotechnological platform for sustainable and eco-friendly open fermentation with *** evaluate this hypothesis,we integrated the N-acetylglucosamine(GlcNAc)pathway into *** *** nag genes were knocked out to obstruct the utilization of GlcNAc,and then 16 exogenous gna1s co-expressing with EcglmS were introduced to strengthen the flux of GlcNAc pathway,*** further enhance GlcNAc production,we fine-tuned promoter strength of the two genes and inactivated two genes alsS and alsD to prevent the production of ***,unsterile open fermentation was carried out using simulated seawater and a chemically defined medium,resulting in the production of 9.2 g/L GlcNAc in 14 *** is the first report for de-novo synthesizing GlcNAc with a Vibrio strain,facilitated by an unsterile open fermentation process employing seawater as a substitute for fresh *** development establishes a basis for production of diverse valuable chemicals using Vibrio strains and provides insights into biomanufacture.

关键词： Vibrio Open fermentation Metabolic engineering N-acetylglucosamine

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Spatial Distribution of Soil Organic Matter and Nutrients in the Pear Orchard Under Clean and Sod Cultivation Models

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Journal of Integrative Agriculture 2013年第2期12卷 344-351页

作者： XU Ling-fei ZHOU Peng HAN Qing-fang LI Zhi-hui YANG Bao-ping NIE Jun-feng College of Horticulture Northwest A&F University Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China Ministry of Agriculture Key Laboratory of Crop Production and Ecology Minister of Agriculture

The soil organic matter and nutrients are fundamental for the sustainability of pear production, but little is known about the spatial distribution of soil organic matter and nutrients in a pear orchard. With the soil of the pear （cv. Dangshansu on *** Bunge. rootstock） orchard under clean and sod cultivation models as test materials, the experiment was conducted to evaluate spatial variability of soil organic matter （SOM）, total nitrogen （STN）, total phosphorus （STP）, total potassium （STK）, available nitrogen （SAN）, and available potassium （SAK） in and between rows at different soil depths （0-60 cm）. The SOM, STN, STP, STK, SAN and SAK of the different soil layers under the two tillage models were different in the vertical direction. The SOM, STN, STP and SAN in the 0-20 cm soil layer were higher than those in the 20-40 and 40- 60 cm soil layers. The STK of 40-60 cm soil layer was higher than that in the 0-20 and 20-40 cm soil layers. The STK increased with the depth of soil in the vertical direction in the clean cultivated pear orchard. Variability of the SOM, STN, STP, STK, SAN and SAK of sample sites in between rows of the same soil layer was found in the pear orchard soil in the horizontal direction under clean and sod cultivation management systems, except that STK of all sites did not show the difference in identical soil layers in the pear orchard under clean cultivation. The sod cultivation model improved the SOM, STN, and STK in the 0-20 cm soil layer in the pear orchard, and the three components increased by 12.8, 12.7 and 7.3% compared to clean cultivation, respectively. The results can be applicable to plan collection of orchard soil samples, assess orchard soil quality, and improve orchard soil management practices.

关键词： spatial distribution soil organic matter soil nutrients clean cultivation sod cover pear orchard

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