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Distributed algorithms for solving the convex feasibility problems

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Science China(Information Sciences) 2020年第8期63卷 242-244页

作者： kaihong lu Gangshan JING Long WANG Center for Complex Systems School of Mechano-electronic EngineeringXidian University Department of Applied Mathematics Hong Kong Polytechnic University Center for Systems and Control College of EngineeringPeking University

Dear editor,Along with the recent adoption of multi-agent networks [1–9], consensus-based distributed optimization has been extensively investigated. In [1], a distributed algorithm that combines the consensus and subgradient algorithms was developed for obtaining the solution of the unconstrained convex distributed optimization problems. In [2], a distributed discrete-time projected subgradient al-

关键词： Multi-agent systems Consensus Convex inequalities Subgradient Projection

Random gradient-free method for online distributed optimization with strongly pseudoconvex cost functions

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Control Theory and Technology 2024年第1期22卷 14-24页

作者： Xiaoxi Yan Cheng Li kaihong lu Hang Xu School of Electrical and Information Engineering Jiangsu UniversityZhenjiang212013JiangsuChina College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao266590ShandongChina

This paper focuses on the online distributed optimization problem based on multi-agent systems. In this problem, each agent can only access its own cost function and a convex set, and can only exchange local state information with its current neighbors through a time-varying digraph. In addition, the agents do not have access to the information about the current cost functions until decisions are made. Different from most existing works on online distributed optimization, here we consider the case where the cost functions are strongly pseudoconvex and real gradients of the cost functions are not available. To handle this problem, a random gradient-free online distributed algorithm involving the multi-point gradient estimator is proposed. Of particular interest is that under the proposed algorithm, each agent only uses the estimation information of gradients instead of the real gradient information to make decisions. The dynamic regret is employed to measure the proposed algorithm. We prove that if the cumulative deviation of the minimizer sequence grows within a certain rate, then the expectation of dynamic regret increases sublinearly. Finally, a simulation example is given to corroborate the validity of our results.

关键词： Multi-agent system Online distributed optimization Pseudoconvex optimization Random gradient-free method

Zeroth-Order Methods for Online Distributed Optimization with Strongly Pseudoconvex Cost Functions

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Journal of Systems Science and Information 2024年第1期12卷 145-160页

作者： Xiaoxi YAN Muyuan MA kaihong lu School of Electrical and Information Engineering Jiangsu UniversityZhenjiang 212013China School of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China

This paper studies an online distributed optimization problem over multi-agent *** this problem,the goal of agents is to cooperatively minimize the sum of locally dynamic cost *** from most existing works on distributed optimization,here we consider the case where the cost function is strongly pseudoconvex and real gradients of objective functions are not *** handle this problem,an online zeroth-order stochastic optimization algorithm involving the single-point gradient estimator is *** the algorithm,each agent only has access to the information associated with its own cost function and the estimate of the gradient,and exchange local state information with its immediate neighbors via a time-varying *** performance of the algorithm is measured by the expectation of dynamic *** mild assumptions on graphs,we prove that if the cumulative deviation of minimizer sequence grows within a certain rate,then the expectation of dynamic regret grows ***,a simulation example is given to illustrate the validity of our results.

关键词： multi-agent systems strongly pseudoconvex function single-point gradient estimator online distributed optimization

NMR-based metabolomic responses of freshwater gastropod Bellamya aeruginosa to MC-producing and non MC-producing Microcystis aeruginosa

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Journal of Oceanology and Limnology 2022年第1期40卷 260-272页

作者： Wen YANG Yangfang YE kaihong lu Zhongming ZHENG Jinyong ZHU School of Marine Science Ningbo UniversityNingbo 315800China

Molluscan metabolomic analysis is essential for the understanding of the regulatory mechanism of aquatic invertebrate in response to hepatotoxic microcystins(MCs)*** understand the system responses of the gastropod to MC exposure,metabolomic alterations caused by two strains(MC-producing and non MC-producing)of Microcystis aeruginosa were characterized indiff erent biological matrices(hepatopancreas and muscle)of Bellamya aeruginosa(Gastropoda)using 1 H nuclear magnetic resonance(NMR)spectroscopy combined with MCs detections after exposure for 1,7,and 14 *** ELISA analysis showed that no MCs was detected in both tissues after non MC-producing *** exposure,MCs concentrations were increasing in the hepatopancreas(from 1.29±0.48μg/g to 3.17±0.11μg/g)and foot muscle(from 0.07±0.02μg/g to 0.21±0.08μg/g)after 14-d exposure of MC-producing ***,we observed that MC induced signifi cant increase in creatine,a variety of amino acids(leucine,isoleucine,valine,threonine,alanine,methionine,glutamate,aspartate,and lysine),carboxylic acids(lactate,acetate,and D-3-hydroxybutyrate),and choline and its derivatives(phosphocholine and glycerophosphocholine)but decreased the energy substance(lipids,glucose,and glycogen)in the ***,no signifi cant metabolite diff erences were observed in the muscle between MC-producing and non MC-producing cyanobacteria treated *** results suggest that MC exposure may cause hepatic energy expenditure accompanied with various metabolic disorders that involve lipid metabolism,protein catabolism,osmoregulation,glycolysis,glycogenolysis,and tricarboxylic acid(TCA)***,metabolic perturbation was aggravated as the level of accumulated MCs raised over time in the MC-producing cyanobacteria *** fi ndings indicated that MCs accumulation might lead to oxidative-stress-mediated damage of mitochondria functions.

关键词： Bellamya aeruginosa Microcystis aeruginosa metabolomic nuclear magnetic resonance microcystin

Stable isotopes of carbon and nitrogen as indicators of food source of the gastropods Bellamya aeruginosa

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Stable isotopes of carbon and nitrogen as indicators of food...

Can freshwater snail Bellamya aeruginosa affect phytoplankton community and water quality

中国海洋湖沼学会第十次全国会员代表大会暨学术研讨会

作者： lu kaihong Zhu Jinyong Zhang Kexin 宁波大学

Suspension feeding behavior of B. aeruginosa was observed in detail visually. Food sources for snails were estimated using stable carbon and nitrogen isotope ratios in the field. δ15N mass balance estimates indicated that B. aeruginosa obtained only 19.9% of its diets from deposit in Meihu Reservoir. But the proportion of deposit was 57.7% and 77.3% in Campus pond and Tingxia Reservoir, respectively. These results suggested that B. aeruginosa can utilize the suspension organic matter in the field, but the proportion of food consumed by snail depended on the availability of suitable food in the ambient. A three month feeding experiments were also conducted to confirm whether snails assimilate five types of diets. The stable carbon isotope ratios of hepatopancreas of B. aeruginosa fed green alga （-30.0‰）, deposit （-30.1‰） or mixtures （-29.9‰ for algal mixture, -30.2‰ for mixture of alga and deposit） were closer to that of diet at the end of the experiment. These revealed that snails were able to assimilate suspension algae under laboratory conditions. However, the snails that were fed toxic M. aeruginosa showed δ13C values （-32.2‰） similar to the starveling animals （-32.4‰） and lower than the control animals （-31.0‰） after three months experiment. These findings suggest that B. aeruginosa is a facultative suspension feeder and can exhibit feeding selectivity in some extent.

关键词： Bellamya aeruginosa Microcystis aeruginosa stable isotope food sources

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Can freshwater snail Bellamya aeruginosa affect phytoplankto...

Foraging inhibition in two cladocerans feeding on Microcystis aeruginosa

中国海洋湖沼学会第十次全国会员代表大会暨学术研讨会

作者： Zhu Jinyong lu kaihong Liu Xiasong Ningbo University

The aim of the present microcosm experiment was to determine if the freshwater snail Bellamya aeruginosa influence phytoplankton community and water quality parameters. Three treatments of different snail densities （Low, Mid and High） and a control （no snail） were set up in twelve enclosures. Chlorophyll a （chl a）, transparency （SD）, water temperature （WT）, dissolved oxygen （DO）, pH, nutrients and abundance of phytoplankton were determined on day 0, 3, 7, 11, 15, 23, 31, 46 and 61, respectively. The concentration of total chl a decreased and SD increased in the treatments, while the proportion of chl a of cyanobacteria increased. Bellamya seemed to result indirectly in a decrease of DO due to decreasing the algal biomass rather than respiration. A significant decreasing in nitrogen-phosphorus ratios in the treatments was observed. Abundance of colonial green algae decreased whereas that of cyanobacteria and flagellate increased over time in an enclosed system. Principal response curves showed that both phytoplankton and water quality in the low density treatment, deviations from the control were insignificantly in the early stage of experiment, even tended to return to levels close to control later. Meanwhile, the mid and high density treatments continued to show different phytoplankton community from the control, and the magnitude of this difference was much larger compared to that in the early stage of experiment. These results indicate that the presence of snails resulted in a significant change of water physicochemical properties and phytoplankton community.

关键词： Bellamya aeruginosa phytoplankton water quality principal response curves

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Foraging inhibition in two cladocerans feeding on Microcysti...

莱啉酰亚胺类化合物的邻位C—H键功能化研究进展

中国海洋湖沼学会第十次全国会员代表大会暨学术研讨会

作者： Zhu Jinyong lu kaihong Sun Sizhi Zhang Kexin Ningbo University

Bloom-forming cyanobacteria are known to negatively affect their herbivores, but the possible reasons leading to the foraging inhibition of different cladocerans are uncertain and controversial so far. Hence, in order to understand how cyanobacteria affect the feeding behavior of cladocerans with different body sizes, feeding rates （FR） of zooplankton cladocerans Daphnia carinata and Moina macrocopa on the mixture of toxic or non-toxic Microcystis aeruginosa with Scenedesmus quadricauda during a 24-h period was investigated. FR of Moina was found generally low in the mixed toxic Microcystis diets, except for the sudden increase after 8 h of exposure, while FR of Daphnia decreased continuously in the mixed toxic diets. The dynamics of FR of both cladocerans on specific algae was similar to that of the total FR. There is no apparent selectivity displayed by both cladocerans on the mixed diets. There is no significant difference between the strains of Microcystis, suggesting that the feeding pattern of Moina maybe more of avoiding Microcystis rather than feeding inhibition resulted from the toxicity of algae. Unlike Moina, there was significant difference in Daphnia between the strains of Microcystis over time. The reason of feeding inhibition of Daphnia might be toxicity after continuous exposure to the toxic cyanobacteria.

关键词： avoidance cladocerans cyanobacteria feeding inhibition toxicity

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有机化学 2023年第3期43卷 1000-1011页

作者：吴孔川卢铠洪林建斌张慧君厦门大学化学化工学院厦门361005

莱啉酰亚胺是一类重要的功能有机染料.独特的缺电性共轭骨架与优异的光电性质使其成为多环芳烃家族中的重要成员,在有机场效应晶体管、有机光伏器件和生物医学传感等领域具有广阔的应用前景.对莱啉酰亚胺骨架的精准修饰不仅可以有效调... 详细信息

莱啉酰亚胺是一类重要的功能有机染料.独特的缺电性共轭骨架与优异的光电性质使其成为多环芳烃家族中的重要成员,在有机场效应晶体管、有机光伏器件和生物医学传感等领域具有广阔的应用前景.对莱啉酰亚胺骨架的精准修饰不仅可以有效调控分子能级,还有利于实现分子间的可控组装,是高效创制新型π-分子材料的有效手段.早期,受合成方法的限制,莱啉酰亚胺骨架母核修饰的位点主要局限于电子云密度稍高的湾位,但在该位点引入取代基会扭曲π-平面,不利于π-分子之间的有效堆积.莱啉酰亚胺骨架邻位选择性修饰不影响母核的平面性,近年来受到广泛关注,催生出系列莱啉酰亚胺邻位C—H键功能化的新策略.根据成键类型不同,以苝二酰亚胺和萘二酰亚胺为例,系统总结了莱啉酰亚胺骨架邻位C—H键功能化的方法,以及邻位修饰对莱啉骨架光电性质和组装的影响.

关键词：莱啉酰亚胺 π-分子材料 C—H键活化过渡金属催化

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不同氮磷浓度及氮磷比对龙须菜生长和琼胶含量的影响

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农业工程学报 2006年第8期22卷 209-213页

作者：徐永健陆开宏管保军宁波大学生命科学与生物工程学院宁波315211

本文研究了不同氮磷浓度及氮磷比对龙须菜生长和琼胶含量的影响。结果表明：污染环境中的两种不同化合态氮对龙须菜的生长和琼胶含量的影响没有差异，在试验范围内（氨氮0～50μmol／L；硝氮0～100μmol／L），随着氮浓度升高，龙须菜... 详细信息

本文研究了不同氮磷浓度及氮磷比对龙须菜生长和琼胶含量的影响。结果表明：污染环境中的两种不同化合态氮对龙须菜的生长和琼胶含量的影响没有差异，在试验范围内（氨氮0～50μmol／L；硝氮0～100μmol／L），随着氮浓度升高，龙须菜的生长速率增加而琼胶含量下降；环境中的磷对龙须菜生长的影响与氮相似，但对琼胶含量的影响却与氮相反；此外，不同的氮磷比对龙须菜的生长和琼胶含量也有很大影响，本试验中10：1的氮磷比，龙须菜生长最好；而1：1的氮磷比，藻体的琼胶含量最高。因此，在实际应用中，收获龙须菜前，要根据所作用环境的不同，对收获的海藻作适当的处理，如让海藻在有利于琼胶合成的环境中（低氮磷比、氮限制、富磷的环境）暂养2周，使得所收获龙须菜的琼胶产量高、质量好。

关键词：龙须菜生长速率琼胶含量氮磷