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International Journal of Biomathematics 2024年第2期17卷 233-262页

作者： Guo-Feng Feng Jiaqi chen bin Ge School of Mathematical Sciences Harbin Engineering University Harbin 150001 P.R.China

In this paper,we consider the long-term sustainability of the northeast Korean *** propose a class of natural Korean pine population system with time delay and diffusion ***,by analyzing the roots distribution of the characteristic equation,we study the stability of the model system with diffusion terms and prove the occurrence of Hopf ***,we introduce lactation time delay into a population model with a diffusion term,based on stability theory of ordinary differential equation,norm form methods and center manifold theorem,the stability of bifurcating periodic solutions and the relevant formula for the direction of Hopf bifurcation are ***,some numerical simulations are given.

关键词： Pinus koraiensis populations delay diffusion term Hopf bifurcation periodic solution

The early life immune dynamics and cellular drivers at single-cell resolution in lamb forestomachs and abomasum

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Journal of Animal Science and Biotechnology 2024年第1期15卷 218-235页

作者： Kailang Huang bin Yang Zebang Xu Hongwei chen Jiakun Wang Institute of Dairy Science College of Animal SciencesZhejiang UniversityHangzhou 310058China Key Laboratory of Molecular Animal Nutrition Ministry of EducationZhejiang UniversityHangzhou 310058China

Background Four-chambered stomach including the forestomachs(rumen,reticulum,and omasum)and abomasum allows ruminants convert plant fiber into high-quality animal *** early development of this four-chambered stomach is crucial for the health and well-being of young ruminants,especially the immune ***,the dynamics of immune development are poorly *** We investigated the early gene expression patterns across the four-chambered stomach in Hu sheep,at 5,10,15,and 25 days of *** found that forestomachs share similar gene expression patterns,all four stomachs underwent widespread activation of both innate and adaptive immune responses from d 5 to 25,whereas the metabolic function were significantly downregulated with *** constructed a cell landscape of the four-chambered stomach using single-cell *** transcriptomic and single-cell transcriptomic analyses revealed that the immune-associated module hub genes were highly expressed in T cells,monocytes and macrophages,as well as the defense-associated module hub genes were highly expressed in endothelial cells in the four-stomach ***,the non-immune cells such as epithelial cells play key roles in immune *** communication analysis predicted that in addition to immune cells,non-immune cells recruit immune cells through macrophage migration inhibitory factor signaling in the *** Our results demonstrate that the immune and defense responses of four stomachs are quickly developing with age in lamb's early *** also identified the gene expression patterns and functional cells associated with immune ***,we identified some key receptors and signaling involved in immune *** results help to understand the early life immune development at single-cell resolution,which has implications to develop nutritional manipulation and health management strategies based on specific targets including key

关键词： Early life Forestomachs Four-chambered stomach Immune cells Immune system maturation MIF signaling Rumen Ruminant development Single-cell transcriptomic sequencing

A modified back analysis method for deep excavation with multi-objective optimization procedure

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1373-1387页

作者： chenyang Zhao Le chen Pengpeng Ni wenjun Xia bin Wang State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China Guangdong Research Center for Underground Space Exploitation Technology School of Civil EngineeringSun Yat-sen UniversityGuangzhou510275China Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Zhuhai519000China Jiangsu Provincial Transportation Engineering Construction Bureau Nanjing210004China

Real-time prediction of excavation-induced displacement of retaining pile during the deep excavation process is crucial for construction *** paper proposes a modified back analysis method with multi-objective optimization procedure,which enables a real-time prediction of horizontal displacement of retaining pile during *** opposed to the traditional stage-by-stage back analysis,time series monitoring data till the current excavation stage are utilized to form a multi-objective ***,the multi-objective particle swarm optimization (MOPSO) algorithm is applied for parameter *** optimized model parameters are immediately adopted to predict the excavation-induced pile deformation in the continuous construction *** achieve efficient parameter optimization and real-time prediction of system behavior,the back propagation neural network (BPNN) is established to substitute the finite element model,which is further implemented together with MOPSO for automatic *** proposed approach is applied in the Taihu tunnel excavation project,where the effectiveness of the method is demonstrated via the comparisons with the site monitoring *** method is reliable with a prediction accuracy of more than 90%.Moreover,different optimization algorithms,including non-dominated sorting genetic algorithm (NSGA-II),Pareto Envelope-based Selection Algorithm II (PESA-II) and MOPSO,are compared,and their influences on the prediction accuracy at different excavation stages are *** results show that MOPSO has the best performance for high dimensional optimization task.

关键词： Multi-objective optimization Back analysis Surrogate model Multi-objective particle swarm optimization(MOPSO) Deep excavation

The environment,especially the minimum temperature,affects summer maize grain yield by regulating ear differentiation and grain development

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Journal of Integrative Agriculture 2024年第7期23卷 2227-2241页

作者： Jing chen Baizhao Ren bin Zhao Peng Liu Jiwang Zhang State Key Laboratory of Crop Biology/College of Agronomy Shandong Agricultural UniversityTai’an 271018

Ear differentiation,grain development and their interaction with factors in the growing environment,such as temperature,solar radiation and precipitation,greatly influence grain number and grain weight,and ultimately affect summer maize *** this study,field experiments involving different sowing dates were conducted over three years to evaluate the effects of temperature factors,average solar radiation and total precipitation on the growth process,ear differentiation,fertilization characteristics,grain filling and yield of summer maize varieties with different growth *** hybrids were evaluated in Huang-Huai-Hai Plain(HHHP),China from 2018 to 2020 with five different sowing *** results showed that the grain yield formation of summer maize was strongly impacted by the environment from the silking(R1)to milking(R3)*** minimum temperature(AT_(min))was the key environmental factor that determined *** in the length of the growing season(r=–0.556,P<0.01)and the total floret number on ear(R^(2)=0.200,P<0.001)were found when AT_(min) was elevated from the emerging(VE)to R1 *** grain-filling rate(R^(2)=0.520,P<0.001)and the floret abortion rate on ear(R^(2)=0.437,P<0.001)showed quadratic relationships with AT_(min) from the R1 to physiological maturity(R6)stage,while the number of days after the R1 stage(r=–0.756,P<0.01)was negatively correlated with AT_(min).An increase in AT_(min) was beneficial for the promotion of yield when it did not exceeded a certain level(above 23°C during the R1–R3 stage and 20–21°C during the R1-R6 stage).Enhanced solar radiation and precipitation during R1–R6 increased the grain-filling rate(R^(2)=0.562,P<0.001 and R^(2)=0.229,P<0.05,respectively).Compared with short-season hybrids,full-season hybrids showed much greater suitability for a critical *** coordinated regulation of AT_(min),ear differentiation and grain development at the pre-and post-silking stages improved maize yie

关键词： sowing date hybrid maturity growing environment ear differentiation and grain development

Numerical multi-physical optimization of operating condition and current collecting setup for large-area solid oxide fuel cells

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Frontiers in Energy 2024年第3期18卷 356-368页

作者： chengrong YU Zehua PAN Hongying ZHANG bin chen Wanbing GUAN bin MIAO Siew Hwa CHAN Zheng ZHONG Yexin ZHOU School of Science Harbin Institute of TechnologyShenzhen 518055China Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Institute of Deep Earth Sciences and Green EnergyShenzhen UniversityShenzhen 518060China Key Laboratory of Advanced Fuel Cells and Electrolyzers Technology of Zhejiang Province Ningbo Institute of Materials Technology and Engineering of the Chinese Academy of SciencesNingbo 315201China Energy Research Institute at NTU(ERIAN) Nanyang Technological UniversitySingapore 639798Singapore

Due to the depletion of traditional fossil fuels and the aggravation of related environmental problems,hydrogen energy is gaining more attention all over the *** oxide fuel cell(SOFC)is a promising power generation technology operating on hydrogen with a high *** further boost the power output of a single cell and thus a single stack,increasing the cell area is an effective ***,it was recently found that further increasing the effective area of an SOFC single cell with a flat-tubular structure and symmetric double-sided cathodes would result in a lower areal *** this work,a multi-physical model is built to study the effect of the effective area on the cell *** distribution of different physical fields is systematically *** of the cell performance is also pursued by systematically tuning the cell operating condition and the current collection *** improvement of 42%is revealed by modifying the inlet gas flow rates and by enhancing the current *** the future,optimization of cell geometry will be performed to improve the homogeneity of different physical fields and thus to improve the stability of the cell.

关键词： solid oxide fuel cell(SOFC) large effective area flow rate discharge performance current collection

Enhancement and Removal of PM_(2.5)by Cold and Warm Air Masses Accompanying Certain Synoptic Weather Systems across Hangzhou,China during 2014-2020

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Journal of Meteorological Research 2024年第3期38卷 620-634页

作者： Bu YU Feng chen Hanqing KANG bin ZHU Hongnian LIU Hangzhou Meteorological Bureau Hangzhou310051China Hangzhou International Urbanology Research Center for Urban Governance Studies Hangzhou311121China Zhejiang Institute of Meteorological Sciences Hangzhou310008China Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration Nanjing University of Information Science&TechnologyNanjing210044China School of Atmospheric Sciences Nanjing UniversityNanjing210023China

Local air pollution is strongly affected by synoptic weather systems,such as fronts,troughs,low-altitude vortices,or high-altitude ***,few studies have analyzed the meteorological properties of cold or warm air masses associated to these systems and their impact on local air *** this study,hourly observations of fine particulate matter(diameter of up to 2.5µm,i.e.,PM_(2.5)),wind(V),temperature(T),pressure(P),and precipitation(R),acquired in Hangzhou in 2014-2020,were *** this analysis,weather patterns were categorized into 27 types;89 and 94 cases illustrating the passage of warm and cold air masses over Hangzhou were identified,respectively;the influence of air mass temperature,wind speed,and wind direction on PM_(2.5) concentrations and local accumulation or removal was *** main results are as follows.(1)Pollution events occurred more frequently for cold than for warm air masses,but average pollutant concentration was lower for cold air masses;(2)48%of the cold air mass cases corresponded to PM_(2.5) decreases and 52%to PM_(2.5) increases,with strong cold air masses(ΔT_(24h)>4°C;∣V∣_(average)>4 m s^(−1))markedly reducing local pollution,but weak cold air masses(ΔT24h4°C)reduced the PM_(2.5) concentration whereas weaker winds(∣V∣_(average)<2 m s^(−1))increased it;and(4)PM_(2.5) concentration decreased sharply within 4 h after the passage of strong cold air masses,but more gradually within 14 h after the passage of strong warm air *** results considerably improve the current understanding of the influence of cold and warm air masses on local pollution patterns.

关键词： weather type air mass enhancement removal meteorological condition

Mussel-inspired PTW@PDA composites for developing high-energy gun propellants with reduced erosion and enhanced mechanical strength

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Defence Technology（防务技术） 2024年第2期32卷 675-690页

作者： Xijin Wang Zhitao Liu Pengfei Sun Feiyun chen bin Xu Xin Liao School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094JiangsuChina China North Industries Group Corporation Limited Beijing 100045China

The severe erosion and inadequate mechanical strength are prominent challenges for high-energy gun *** address it,novel PTW@PDA composites was prepared by polydopamine(PDA)-modifying onto potassium titanate whisker(PTW,K_(2)Ti_(6)O_(13)),and after was incorporated into gun propellant as erosion-reducing and mechanical-reinforcing *** interfacial characterizations results indicated that as-prepared PTW@PDA composites exhibits an enhanced surface compatible with propellant matrix,thereby facilitating their dispersion into propellants more effectively than raw PTW *** to original propellants,PTW@PDA-modified propellants exhibited significant less erosion,with a Ti-Kbased protective coating being detected on the eroded *** 0.5 wt%and 1.0 wt%addition of PTW@PDA significantly improved impact,compressive and tensile strength of *** the inevitably reduction in relative force,PTW@PDA slightly increase propellant burning rate while exerting little adverse impact on propellant dynamic *** strategy can provide a promising alternative to develop high-energy gun propellant with less erosion and more mechanical strength.

关键词： High energy gun propellant Potassium titanate whiskers Polydopamine modification Erosion inhibitors Mechanical reinforcing fillers

Observer-Based Adaptive Robust Precision Motion Control of a Multi-Joint Hydraulic Manipulator

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1213-1226页

作者： Zheng chen Shizhao Zhou Chong Shen Litong Lyu Junhui Zhang bin Yao State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027 Ocean College Zhejiang UniversityZhoushan 316021China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050000 State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China School of Mechanical Engineering Purdue UniversityWest LafayetteIN 47907 USA

Hydraulic manipulators are usually applied in heavy-load and harsh operation ***,when faced with a complex operation,the traditional proportional-integral-derivative(PID)control may not meet requirements for high control ***-based full-state-feedback control is an effective alternative,but the states of a hydraulic manipulator are not always available and reliable in practical applications,particularly the joint angular velocity *** that it is not suitable to obtain the velocity signal directly from differentiating of position measurement,the low-pass filtering is commonly used,but it will definitely restrict the closed-loop bandwidth of the whole *** avoid this problem and realize better control performance,this paper proposes a novel observerbased adaptive robust controller(obARC)for a multi-joint hydraulic manipulator subjected to both parametric uncertainties and the lack of accurate velocity ***,a nonlinear adaptive observer is first designed to handle the lack of velocity measurement with the consideration of parametric ***,the adaptive robust control is developed to compensate for the dynamic uncertainties,and the close-loop system robust stability is theoretically proved under the observation and control ***,comparative experiments are carried out to show that the designed controller can achieve a performance improvement over the traditional methods,specifically yielding better control accuracy owing to the closed-loop bandwidth breakthrough,which is limited by low-pass filtering in fullstate-feedback control.

关键词： handle Observer filtering

Learning Scalable Task Assignment with Imperative-Priori Conflict Resolution in Multi-UAV Adversarial Swarm Defense Problem

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Journal of Systems Science & Complexity 2024年第1期37卷 369-388页

作者： ZHAO Zhixin chen Jie XIN bin LI Li JIAO Keming ZHENG Yifan School of Electronics and Information Engineering Tongji UniversityShanghai 201804China Shanghai Institute of Intelligent Science and Technology Tongji UniversityShanghai 201804China School of Automation Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Autonomous Intelligent Unmanned Systems Beijing 100081China Shanghai Institute of Intelligent Science and Technology Tongji UniversityShanghai 201804China.

The multi-UAV adversary swarm defense(MUASD)problem is to defend a static base against an adversary UAV swarm by a defensive UAV *** the problem into task assignment and low-level interception strategies is a widely used ***-based approaches for task assignment are a promising *** studies on learning-based methods generally assume decentralized decision-making architecture,which is not beneficial for conflict *** contrast,centralized decision-making architecture is beneficial for conflict resolution while it is often detrimental to *** achieve scalability and conflict resolution simultaneously,inspired by a self-attention-based task assignment method for sensor target coverage problem,a scalable centralized assignment method based on self-attention mechanism together with a defender-attacker pairwise observation preprocessing(DAP-SelfAtt)is ***,an imperative-priori conflict resolution(IPCR)mechanism is proposed to achieve conflict-free ***,the IPCR mechanism is parallelized to enable efficient *** validate the algorithm,a variant of proximal policy optimization algorithm(PPO)is employed for training in scenarios of various *** experimental results show that the proposed algorithm not only achieves conflict-free task assignment but also maintains scalability,and significantly improve the success rate of defense.

关键词： Conflict resolution reinforcement learning scalability task assignment.