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Preparation of high water-retaining biochar and its mechanism of alleviating drought stress in the soil and plant system

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Biochar 2021年第4期3卷 579-590页

作者： Hui Li zhongxin Tan Hubei Key Laboratory of Soil Environment and Pollution Remediation Key Laboratory of Arable Land Conservation(Middle and Lower Reaches of Yangtse River)Ministry of Agriculture and Rural AffairsCollege of Resources and EnvironmentHuazhong Agricultural UniversityNo.1 Lion Hill StreetHongshan DistrictWuhan 430070People’s Republic of China

To explore the effect of biochar on alleviating plant drought stress after being applied to soil,we prepared biochar using rice straw as raw material according to different pyrolysis temperatures(400,600 and 800°C)and reaction atmosphere(CO_(2)and N_(2)).The effect of different pyrolysis conditions on the water retention performance of biochar was *** early high water-retaining biochar materials were selected and wheat seeds were selected for the verification experiment of returning to the field in *** with high porosity(specific surface area and total pore volume)and more surface hydrophilic functional groups(mainly-OH and-COOH)can indeed improve soil water retention *** is mainly reflected in the increase in the dry weight and fresh weight of wheat and the soil moisture content in the treatment group with the addition of biochar water retention *** them,the growth rates of fresh weight and dry weight of wheat in the C800 treatment group were 11.51%and 10.64%,and the soil moisture content increased by 1.89%.It is worth noting that the application of biochar cannot completely alleviate the impact of drought stress on plants,but it can reduce the amount of water irrigation to a certain *** the quality of biochar,the biochar material(C800)prepared under the pyrolysis temperature of 800°C and the reaction atmosphere of CO_(2)has high water retention performance.

关键词： Biochar Pyrolysis temperature Reaction atmosphere Water retention performance Drought stress

A PI+R Control Scheme Based on Multi-Agent Systems for Economic Dispatch in Isolated BESSs

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IEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2154-2165页

作者： Yalin Zhang zhongxin Liu Zengqiang Chen College of Artificial Intelligence Nankai UniversityTianjin 300350 Tianjin Key Laboratory of Interventional Brain-Computer Interface and Intelligent Rehabilitation Nankai UniversityTianjin 300350China IEEE

Battery energy storage systems(BESSs)are widely used in smart ***,power consumed by inner impedance and the capacity degradation of each battery unit become particularly severe,which has resulted in an increase in operating *** general economic dispatch(ED)algorithm based on marginal cost(MC)consensus is usually a proportional(P)controller,which encounters the defects of slow convergence speed and low control *** order to solve the distributed ED problem of the isolated BESS network with excellent dynamic and steady-state performance,we attempt to design a proportional integral(PI)controller with a reset mechanism(PI+R)to asymptotically promote MC consensus and total power mismatch towards 0 in this *** be frank,the integral term in the PI controller is reset to 0 at an appropriate time when the proportional term undergoes a zero crossing,which accelerates convergence,improves control accuracy,and avoids *** eigenvalues of the system under a PI+R controller is well analyzed,ensuring the regularity of the system and enabling the reset *** ensure supply and demand balance within the isolated BESSs,a centralized reset mechanism is introduced,so that the controller is distributed in a flow set and centralized in a jump *** cope with Zeno behavior and input delay,a dwell time that the system resides in a flow set is *** on this,the system with input delays can be reduced to a time-delay free *** the capacity limitation of the battery,a modified MC scheme with PI+R controller is *** correctness of the designed scheme is verified through relevant simulations.

关键词： Battery energy storage system(BESS) distributed control economic dispatch multi-agent system reset control

Numerical simulation of radar surveillance for the ship target in oceanic clutters

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Chinese Science Bulletin 2002年第21期47卷 1766-1771页

作者： JIN Yaqiu LI zhongxin Center for Wave Scattering and Remote Sensing Fudan UniversityShanghai 200433China

A fast iterative approach of generalized forward-backward method with the spectrum acceleration algorithm (GFBM/SAA) is developed for solving electromagnetic field integral equation and is applied to numerical simulation of radar surveillance of the ship target in oceanic clutters. Randomly rough surface is realized by the Monte Carlo method using the Pierson-Moskowitz spectrum. Numerical results of bistatic and back-scattering from the ship target and oceanic clutters demonstrate the functional dependencies upon the situation of radar surveillance such as the incidence and observation angles, radar altitude, ship RCS and other oceanic conditions.

关键词： radar surveillance ship and sea surface scattering GFBM/SAA.

Reduced-Order Observer-Based Leader-Following Formation Control for Discrete-Time Linear Multi-Agent Systems

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IEEE/CAA Journal of Automatica Sinica 2021年第10期8卷 1715-1723页

作者： zhongxin Liu Yangbo Li Fuyong Wang Zengqiang Chen College of Artificial Intelligence Nankai UniversityTianjin 300350 Tianjin Key Laboratory of Intelligent Robotics Nankai UniversityTianjin 300350China

Formation control of discrete-time linear multi-agent systems using directed switching topology is considered in this work via a reduced-order observer, in which a formation control protocol is proposed under the assumption that each directed communication topology has a directed spanning tree. By utilizing the relative outputs of neighboring agents, a reduced-order observer is designed for each following agent. A multi-step control algorithm is established based on the Lyapunov method and the modified discrete-time algebraic Riccati equation. A sufficient condition is given to ensure that the discrete-time linear multi-agent system can achieve the expected leader-following ***, numerical examples are provided so as to demonstrate the effectiveness of the obtained results.

关键词： Discrete-time systems formation control leader-following multi-agent system reduced-order observer

Solving type-2 fuzzy relation equations via semi-tensor product of matrices

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Control Theory and Technology 2014年第2期12卷 173-186页

作者： Yongyi YAN Zengqiang CHEN zhongxin LIU College of Computer and Control Engineering Nankai University Tianjin Key Laboratory of Intelligent Robotics Nankai University

The problem of solving type-2 fuzzy relation equations is investigated. In order to apply semi-tensor product of matrices, a new matrix analysis method and tool, to solve type-2 fuzzy relation equations, a type-2 fuzzy relation is decomposed into two parts as principal sub-matrices and secondary sub-matrices; an r-ary symmetrical-valued type-2 fuzzy relation model and its corresponding symmetrical-valued type-2 fuzzy relation equation model are established. Then, two algorithms are developed for solving type-2 fuzzy relation equations, one of which gives a theoretical description for general type-2 fuzzy relation equations; the other one can find all the solutions to the symmetrical-valued ones. The results can improve designing type-2 fuzzy controllers, because it provides knowledge to search the optimal solutions or to find the reason if there is no solution. Finally some numerical examples verify the correctness of the results/algorithms.

关键词： Fuzzy control system Type-2 fuzzy logic system Type-2 fuzzy relation Type-2 fuzzy relation equation Semi- tensor product of matrices

Compatible-invariant subset analysis of deterministic finite automata via semi-tensor product of matrices approach

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The Journal of China Universities of Posts and Telecommunications 2018年第5期25卷 75-82页

作者： Zhang Zhipeng Chen Zengqiang Liu zhongxin College of Computer and Control Engineering Nankai University Tianjin Key Laboratory of Intelligent Robotics Nankai University

The compatible-invariant subset of deterministic finite automata（ DFA） is investigated to solve the problem of subset stabilization under the frameworks of semi-tensor product（ STP） of matrices. The concepts of compatibleinvariant subset and largest compatible-invariant subset are introduced inductively for Moore-type DFA,and a necessary condition for the existence of largest compatible-invariant subset is given. Meanwhile,by using the STP of matrices,a compatible feasible event matrix is defined with respect to the largest compatible-invariant *** on the concept of compatible feasible event matrix,an algorithm to calculate the largest compatible-invariant subset contained in a given subset is proposed. Finally,an illustrative example is given to validate the results.

关键词： discrete event dynamical systems (DEDSs) finite automata compatible iuvariant semi-tensor product (STP) compatible feasible eventmatrix

Distributed fuzzy fault-tolerant consensus of leader-follower multi-agent systems with mismatched uncertainties

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Journal of Systems Engineering and Electronics 2021年第5期32卷 1031-1040页

作者： MALIKA Sader WANG Fuyong LIU zhongxin CHEN Zengqiang College of Artificial Intelligence Nankai UniversityTianjin 300350China Tianjin Key Laboratory of Intelligent Robotics Nankai UniversityTianjin 300350China

In this paper,the distributed fuzzy fault-tolerant tracking consensus problem of leader-follower multi-agent systems(MASs)is *** objective system includes actuator faults,mismatched parameter uncertainties,nonlinear functions,and exogenous disturbances under switching communication *** solve this problem,a distributed fuzzy fault-tolerant controller is proposed for each follower by adaptive mechanisms to track the state of the ***,the fuzzy logic system is utilized to approximate the unknown nonlinear *** error estimator is introduced between the mismatched parameter matrix and the input ***,a selective adaptive law with relative state information is adopted and *** calculating the Lyapunov function’s derivative,the coupling terms related to consensus error and mismatched parameter uncertainties can be ***,a numerical simulation is given to validate the effectiveness of the proposed protocol.

关键词： distributed fuzzy fault-tolerant control(FTC) tracking consensus problem leader-follower multi-agent system mismatched parameter uncertainty

Spatial Distribution and Ages of Alkaline Intrusive Rocks in China and Related Tectonics

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Acta Geologica Sinica(English Edition) 1998年第4期72卷 363-381页

作者： YUAN zhongxin BAI Ge Institute of Mineral Deposits Chinese Academy of Geological Sciences 26 Baiwanzhuang Beijing 100037

: On the basis of the geological data from 220 intrusions and isotope ages of 115 rock bodies, the paper discusses the distribution of 18 alkaline intrusive rock belts along deep faults and their relations to the plate tectonic activity. In view of the presence of a large amount of Variscan alkaline rocks of deep-source character, it is inferred that mantle diapirism was very strong in China during the Variscan. Besides anorogenic and postorogenic alkaline granites, there also occur alkaline granites formed in the terminal orogenic stage when the regional tectonic activity was of compressional nature. Finally, the paper discusses the tectonic environment of the Maoniuping nordmarkite in Mianning county, Sichuan province, and the authors consider it to be a compressional environment originating after rift closing.

关键词： alkaline intrusive rock spatial distribution age tectonic China

Changjiang River sediment delivering into the sea in response to water storage of Sanxia Reservoir in 2003

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Acta Oceanologica Sinica 2006年第2期25卷 71-79页

作者： CHU zhongxin ZHAI Shikui CHEN Xiufa College of Marine Geosciences Ocean University of China Qingdao 266003 China Development and Research center China Geological Survey Beijing 100083 China

The Sanxia Reservoir on the Changjiang River stored water from 1 to 10 June and from 25 October to 5 November in 2003, elevating the water level to 135 and 139 m above mean sea level at the dam, respectively. A monthly dataset of water discharge, suspended sediment concentration （SSC） and sediment load of the Changjiang River from 1953 to 2003 measured at the Datong Hydrological Gauging Station of the downstreammost Changjiang River was mainly used to examine the Changjiang River sediment delivering into the sea in 2003 in response to the Sanxia Reservoir water storages in the same year. The results show that （1） compared with those in 2002, 2001, and the multi-yearly （1953-2000） average, both annual SSC and sediment load at Datong in 2003 were markedly reduced, and they were even smaller than the multi-yearly （1953-2000） minimum, although the annual runoff in 2003 did not change largely; and （2） compared with those in the corresponding months in 2002, 2001 and the multi-monthly average from 1953 to 2000, monthly SSC and sediment load at Datong both in June and November of 2003 were also markedly reduced, and those in June 2003 were even smaller than the multi-monthly minimum from 1953 to 2000. These may indicate that sediment sedimentation in the Sanxia Reservoir resulting from the Sanxia Reservoir water storage should be the main cause of the decreased annual and monthly SSC and sediment load of the Changjiang River into the sea in 2003. Besides, it seems that the Sanxia Reservoir water storage in the early June （flood season） of 2003 had more impacts on the decreased monthly SSC into the sea than that in the late October and early November （approximately non-flood season） of 2003.

关键词： Changjiang (Yangtze) River Sanxia Reservoir water storage sediment