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Limits of Uneven Battery Power in Modular Multilevel Converter-based Battery Energy Storage Systems

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 686-695页

作者： yao Pan Xiaofeng Sun Wei Zhao Xin Li yao cai Institute of Electrical Engineering Yanshan UniversityQinhuangdao 066004China

For modular multilevel converter-based battery energy storage systems (MMC-BESS), uneven power among batteries of SMs will be deduced by battery aging, battery fault, etc., which will degrade performance and even lead to system failure. For maintaining the balance of capacitor voltage, this paper analyzes the limits of the uneven power of batteries, which are presented as the current limits in this paper. According to analysis, an analytical method is proposed that only the dc and fundamental frequency components of the arm current are used to calculate current limits. With the current limits it is able to evaluate the reasonability of power distribution among batteries. Meanwhile, increase of fundamental frequency component will enhance the current limits, and the dc component determines the size relationship between the absolute values of the upper and lower current limits. Finally, simulation model and experiment prototype are built for verifying the theoretical analysis and current limits calculation method, and satisfactory results are provided.

关键词： Arm current balance of capacitor voltage current limits MMC-BESS uneven power

L^q Interior Estimates of the Gradient for Weak Solutions of Quasilinear Elliptic Equations

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Acta Mathematica Sinica,English Series 2007年第12期23卷 2225-2234页

作者： Feng Ping yao Yong Yong cai LMAM School of Mathematical Sciences Peking University Bering 100871 P. R. China

The authors present a new proof of L^q interior estimates of the gradient for weak solutions of a quasilinear elliptic equation of p-Laplacian type.

关键词： L^q interior estimates weak solutions quasilinear elliptic maximal function

Control of a Spherical Robot: Path Following Based on Nonholonomic Kinematics and Dynamics

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Chinese Journal of Aeronautics 2011年第3期24卷 337-345页

作者： ZHENG Minghui ZHAN Qiang LIU Jinkun cai yao Robotics Institute Beihang University Beijing 100191 China School of Automation Science and Electrical Engineering Beihang University Beijing 100191 China

This paper presents the controller design for the path following of a spherical mobile robot, BHQ-1. Firstly, a desired velocity for the reference path is deduced from the kinematic model, which cannot be transformed into the classic chained form. Secondly, a necessary torque for the desired velocity is obtained based on the dynamic model. As to the kinematics, a one-dimensional function is selected to measure the two-directional tracking error, and the velocity of rolling forward is reasonably assumed to be constant; therefore the multiple-input multiple-output （MIMO） system is transformed into a single-input single-output （SISO） system. As to the dynamics, both exact dynamics and inexact dynamics with modeling error as well as bounded unknown disturbance are taken into account, based on which a proportional-derivative （PD） controller and a sliding mode controller with adaptive parameters are proposed respectively. Finally, convergence analysis and simulation results are provided to validate these controllers.

关键词： spherical robot path following nonholonomic kinematics dynamics

Importance of microhabitat selection by birds for the early recruitment of endangered trees in a fragmented forest

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Avian Research 2020年第4期11卷 446-451页

作者： Ning Li Zheng Wang yao cai Lin Zhang Institute of Applied Ecology Nanjing Xiaozhuang UniversityNanjing 211171JiangsuChina College of Biology and Environmental Science Nanjing Forestry UniversityNanjing 210037China Hangzhou Key Laboratory for Animal Adaptation and Evolution College of Life and Environmental SciencesHangzhou Normal UniversityHangzhou 311121China

Background:Remnant microhabitats are important for bird habitat selection and plant regeneration in the fragmented ***,empirical information on the consequences of how microhabitat use by birds affects the early recruitment of plants is ***:In this study,we evaluated whether microhabitat selection by the Black Bulbul(Hypsipetes leucocephalus)(***,1789)impacts the early recruitment of the endangered tree species,the Chinese Yew(Taxus chinensis(Pilger)Rehd),in a fragmented forest over a 4-year period(2011–2012,2018–2019).Results:Our results showed the main factors affecting *** microhabitat selection were distance to the nearest *** mature tree,herb cover and density,leaf litter cover,and vegetation ***,the results of logistic regression also highlighted the importance of elevation,distance to light gap and roads,tree cover in bird microhabitat ***,the seed emergence rate in microhabitats used by birds did not differ from the natural forest,which was related to five factors of bird *** Random Forest model showed that seedling emergence rate was increased with leaf litter cover and distance to fallen dead trees,but decreased in relation to herb cover,slope,and ***:Our results highlight the importance of remnant microhabitats in fragmented forests for sustaining forest ecology and optimal *** contribution of microhabitats used by birds to plant recruitment provides insights into how frugivore species contribute to plant regeneration,which should be incorporated in future conservation and management practices of fragmented forests.

关键词： Fragmented forest Hypsipetes leucocephalus Microhabitat use Seedling recruitment Taxus chinensis

Syntheses and Crystal Structures of Two New One-dimensional Double Hydrogen-bonding-chain Complexes [Ni(bipy)_2Cl]·ClO_4 and [Zn(bipy)_2Cl]·BF_4

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Chinese Journal of Structural Chemistry 2007年第5期26卷 541-546页

作者： yao Jing-cai yao Feng-Juan GUO Jin-Bo HUANG Wei GOU Shao-Hua Department of Chemistry Luoyang Normal University Luoyang Henan 471022 China Coordination Chemistry Institute State Key Laboratory of Coordination Chemistry Nanjing University Nanjing Jiangsu 210093 China

Two new transition metal complexes, [Ni（bipy）2Cl]·ClO4 （bipy = 2,2＇-bipyridine） 1 and [Zn（bipy）2Cl]·BF4 2, have been synthesized and characterized by single-crystal X-ray diffraction analysis. Both 1 and 2 crystallize in monoclinic space group P21/n with Z = 4. For 1, a = 10.776（1）, b = 12.067（1）, c = 16.146（2）A, β = 93.021（2）o, V = 2031.9（4） A^3, Mr = 505.98, Dc = 1.654 g/cm^3, μ = 1.255 mm^–1, F（000） = 1032, the final R = 0.0406 and wR = 0.1002 for 3983 observed reflections with Ⅰ 〉 2σ（Ⅰ）. For 2, a = 10.758（4）, b = 12.058（4）, c = 16.135（5） A, β = 104.57（1）o, V = 2025.7（12） A^3, Mr = 500.00, Dc = 1.639 g/cm^3, μ = 1.396 mm^–1, F（000） = 1008, the final R = 0.0470 and wR = 0.1237 for 3759 observed reflections with Ⅰ 〉 2σ（Ⅰ）. The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. A one-dimen-sional zigzag double hydrogen-bonding-chain is generated by the intermolecular M-bipy ···anion···bipy- M hydrogen bonding interactions between the chelating ligands of bipy and anion.

关键词： double hydrogen-bonding-chain 2,2'-bipyridine transition metal

A review of unmanned vehicle distribution optimization models and algorithms

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Journal of Traffic and Transportation Engineering(English Edition) 2023年第4期10卷 548-559页

作者： Jiao Zhao Hui Hu Yi Han yao cai College of Transportaion Engineering Chang'an UniversityXian 710064China School of Automobile Chang'an UniversityXi'an 710064China Yushi Technology(Beijing)Co. Ltd.Beijing 100027China

With the development of globalization and artificial intelligence,as well as the outbreak of COVID-19,unmanned vehicles have played an important role in cargo *** order to better analyze the research directions of unmanned vehicle distribution,this paper summarizes the models and algorithms of unmanned vehicle distribution *** research results show that most of the studies have established the goal of optimizing the total costs or travel *** researchers have begun to study multi-objective optimization problems,but there are certain limitations,so some studies convert these problems into single-objective optimization for solving,such as converting time and energy consumption into cost,waiting time into distance,and time delay into penalty *** the development of unmanned vehicle distribution technology,in future research,a multi-objective model with the lowest cost,the shortest distance and the best security should be established and *** studies have proposed heuristic algorithms for solving the unmanned vehicle distribution problem,and improved optimization solutions have been *** order to ensure the diversity of solution methods,and give consideration to solution time and solution quality,hybrid methods with other algorithms will be a future research direction,for example,the combination of heuristic algorithm and exact *** the gradual deepening of research,integrated distribution of multiple types of unmanned equipment will become the focus of future research.

关键词： Unmanned vehicle Distribution optimization Mathematical model Optimization algorithm

Intelligent Control and Maintenance Man-agement Integrated System Based on Multi-Agents for Coal-Preparation Plant

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Journal of China University of Mining and Technology 2006年第2期16卷 206-210页

作者： MENG Fan-qin WANG yao-cai School of Information and Electrical engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China Aviation Oil Engineering Department Chinese Air Force Xuzhou College Xuzhou Jiangsu 221000 China

This paper discusses the progress of computer integrated processing （CIPS） of coal-preparation and then preserits an intelligence controlled production-process, device-maintenance and production-management system of coal- preparation based on multi-agents （IICMMS-CP）. The construction of the IICMMS-CP, the distributed network control system based on live intelligence control stations and the strategy of implementing distributed intelligence control system are studied in order to overcome the disadvantages brought about by the wide use of the PLC system by coaipreparation plants. The software frame, based on a Multi-Agent Intelligence Control and Maintenance Management integrated system, is studied and the implemention methods of IICMMS-CP are discussed. The characteristics of distributed architecture, cooperation and parallel computing meet the needs of integrated control of coal-preparation plants with large-scale spatial production distribution, densely-related processes and complex systems. Its application further improves the reliability and precision of process control, accuracy of fault identification and intelligence of production adjustment, establishes a technical basis for system integration and flexible production. The main function of the system has been tested in a coal-preparation plant to good effect in stabilizing product quality, improving efficiency and reducing consumption.

关键词： intelligence controlled process multi-agent system computer integrated processing system coal preparation plant

Seed dispersal by wintering ducks in a coastal wetland of eastern China

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Avian Research 2024年第4期15卷 451-457页

作者： Xin Luo Ning Li Wei Tai yao cai Zheng Wang Co-Innovation Center for Sustainable Forestry in Southern China College of Life SciencesNanjing Forestry UniversityNanjing 210037China Institute of Applied Ecology Nanjing Xiaozhuang UniversityNanjing 211171China

Duck species are important vectors for seed dispersal of many plants,contributing significantly to the regeneration of wetland plant ***,research on the temporal changes in diet and the dynamics and differences of seed dispersal among different duck species is still *** this study,we analyzed the diversity of duck community and the diversity of seeds in the feces of different duck species from December to February for 2022–23 and 2023–24 in the coastal wetland of Dafeng,eastern Jiangsu Province,China.A total of 13 duck species were recorded in the four habitats,of which Spot-billed Ducks(Anas zonorhyncha)and Mallards(***)were the most *** diversity and abundance of ducks vary across different habitats,and tidal flat supports the greatest diversity and abundance of *** collected fecal samples from Spot-billed Ducks,Gadwalls(Mareca strepera),Mallards,and Eurasian Teals(***)in the tidal flat,from which seeds belonging to 7 families,13 genera and 15 different plant species were *** were significant differences in seed dispersal among the four duck species,which varied with the *** and Common Teals showed more significant diversity in seed dispersal,with their feces containing a greater variety of plant seeds,which is related to their broader dietary range and ecological ***,the seasonal variation in the number of seeds per feces reflected the availability of seeds in the habitat and the response of ducks to environmental changes,while variations in seed intake among different duck species may be associated with inter-annual weather condition *** results of this study will provide a new perspective for understanding the mechanisms of bird-mediated seed dispersal in coastal wetland and offer preliminary insights for the seed dispersal by Asian ducks.

关键词： Coastal wetland Ducks Duck diversity Duck feces Seed dispersal

Isolation and characterization of insecticidal activity of （Z）- asarone from Acorus calamus L.

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Insect Science 2008年第3期15卷 229-236页

作者： Yingjuan yao Wanlun cai Changju Yang Dong Xue Yanzhang Huang Institute of Urban Pest Control Huazhong Agriculture University Wuhan China

The insecticidal activity of Acorus calamus L. rhizome-derived material against adults of Sitophilus zeamais Motschulsky was examined by using repellency method and contact toxicity. The biologically active constituent of the A. calamus rhizome was separated and identified. The results showed that the ethanol extract of A. calamus had strong repellency and contact effect to S. zeamais and the active constituent of the A. calamus was characterized as （Z）-asarone by spectroscopic analysis. Responses from the tests varied with exposure times and doses. In the repellency test, ethanol extract of A. calamus had 93.92% repellency at 629.08 μg/cm^2 but only 71.38% at 157.27 μg/cm^2 12 h after treatment. As a contrast, （Z）-asarone showed 84.50% repellency at 314.54μg/cm^2 and 77.02% at 78.63 μg/cm^2 12 h after treatment. In the filter paper diffusion test, ethanol extract of A. calamus caused 95.56% and 17.78% mortality to S. zeamais at 314.54 μg/cm^2 and 78.63 μg/ cm^2 4 days after treatment, while （Z）-asarone brought about 100.00% and 15.56% mortality at 40.89 μg/cm^2 and 15.73 μg/cm^2 respectively. These results indicate that the insecticidal activity of the A. calamus extract may be due to （Z）-asarone.

关键词： Acorus calamus asarone natural insecticide Sitophilus zeamais