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Theoretical and experimental investigation of the resonance responses and chaotic dynamics of a bistable laminated composite shell in the dynamic snap-through mode

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 581-602页

作者： Meiqi WU Pengyu lv Hongyuan LI Jiale YAN Huiling DUAN Wei ZHAng State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering ScienceBIC-ESATCollege of EngineeringPeking UniversityBeijing 100871China Nanchang Innovation Institute of Peking University Nanchang 330096China Department of Mechanics Guangxi UniversityNanning 530004China

The dynamic model of a bistable laminated composite shell simply supported by four corners is further developed to investigate the resonance responses and chaotic *** existence of the 1:1 resonance relationship between two order vibration modes of the system is *** resonance response of this class of bistable structures in the dynamic snap-through mode is investigated,and the four-dimensional(4D)nonlinear modulation equations are derived based on the 1:1 internal resonance relationship by means of the multiple scales *** Hopf bifurcation and instability interval of the amplitude frequency and force amplitude curves are *** discussion focuses on investigating the effects of key parameters,e.g.,excitation amplitude,damping coefficient,and detuning parameters,on the resonance *** numerical simulations show that the foundation excitation and the degree of coupling between the vibration modes exert a substantial effect on the chaotic dynamics of the ***,the significant motions under particular excitation conditions are visualized by bifurcation diagrams,time histories,phase portraits,three-dimensional(3D)phase portraits,and Poincare ***,the vibration experiment is carried out to study the amplitude frequency responses and bifurcation characteristics for the bistable laminated composite shell,yielding results that are qualitatively consistent with the theoretical results.

关键词： bistable laminated composite shell dynamic snap-through mode Hopf bifurcation chaotic dynamics vibration experiment

Molecular dynamics study of water molecules nucleation for fine particle removal:Effects of wettability and aggregation modes and comparison with experiment Author links open overlay panel

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Particuology 2024年第8期91卷 106-117页

作者： Junchao Xu Zhipeng Zhang Li lv Yunfei Zhang Yiming Xie Huaqiang Chu School of Energy and Environment Anhui University of TechnologyMaanshan243002China College of Mechanical and Electrical Engineering China Jiliang UniversityHangzhou310018China

Water vapor nucleation on particle's surface plays an important role in dust removal,cloud formation,and particle ***,the selectivity of nucleation sites and the nucleation characteristic of water molecule on the particle's surface are still unclear,especially for the aggregated *** this paper,the effects of particle wettability and aggregation modes on the selectivity of nucleation sites and the nucleation characteristics were investigated using molecular dynamics *** results were compared with our earlier experimental *** illustrates how the contact angle of clusters,the growth velocity,and the growth duration are all influenced by the interaction coefficient between water and ***,the nucleation sites of water molecules on the particle aggregation surface exhibit a definite *** primary indicator of this selectivity is the preferential nucleation of water molecules at the interfaces of linear chain aggregation particles,at the inner side of non-linear chain aggregation particles,and at the centers of ring *** results are in good agreement with our previous experimental *** significantly,additional research has revealed that subcritical-size clusters typically aggregate on two-particle surfaces spacing when the spacing smaller than the critical cluster size.

关键词： Heterogeneous nucleation Water molecule Wettability Aggregation modes Molecule dynamics

Thermodynamic and Economic Analysis of a Conceptual System Combining Sludge Gasification,SOFC,Supercritical CO_(2)Cycle,and Organic Rankine Cycle

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Journal of Thermal Science 2024年第4期33卷 1491-1508页

作者： lv Jiayang WAng Chizhong CHEN Heng PAN Peiyuan XU Gang ZHAng Guoqiang School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China

In order to reduce the environmental impact of conventional sludge treatment methods and to utilize the energy in sludge more effectively,a coupled system based on sewage sludge gasifier(SSG),solid oxide fuel cells(SOFC),supercritical CO_(2)cycle(S-CO_(2)),and organic Rankine cycle(ORC)is *** clean syngas obtained from sludge gasification is mixed with CH4 and then first utilized by the fuel *** exhaust gas from the fuel cell is fully combusted in the afterburning chamber and then enters the bottom cycle system consisting of S-CO_(2)&ORC to generate *** understand the performance of the system,thermodynamic and economic analyses were conducted to examine the project's *** thermodynamics as well as the economics of the coupled system were analyzed to arrive at the following conclusions,the power production of the system is 37.34 MW;the exergy efficiency is 55.62%,and the net electrical efficiency is 61.48%.The main exergy destruction is the gasifier and SOFC,accounting for 62.45%of the total exergy *** takes only6.13 years to repay the construction investment in the novel system,and the project obtains a NPV of 17723820USD during 20 years *** above findings indicate that the new coupled system has a better performance in terms of energy utilization and economy.

关键词： sewage sludge gasifier SOFC supercritical CO_(2)cycle organic Rankine cycle multi-system coupling

Uncovering the coupling effect with energy-related carbon emissions and human development variety in Chinese provinces

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Journal of Environmental Sciences 2024年第5期139卷 527-542页

作者： Liu Chen Yiqi Tan Gengpei lv Weiguang Cai Xiaofeng Gao Rui Li School of Management Science and Real Estate Chongqing UniversityChongqing 400044China State Key Joint Laboratory of Environment Simulation and Pollution Control(SKLESPC) School of EnvironmentTsinghua UniversityBeijing 100084China Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment Ministry of EducationCollege of Environment and EcologyChongqing UniversityChongqing 400044China

Lessening energy-related carbon emissions has become a crucial measure to achieve Chinese carbon *** study is the first to construct a Difference in Carbon pressures-adjusted Human Development Index(DCHDI)model for the purpose of exploring the coupling effect between carbon emissions and human development variety from 2000 to 2019 in Chinese *** demonstrate the following.(1)The total energy-related carbon footprint of 30 provinces in China reached 10.2 billion tons in 2019,with an average annual growth rate of 6.93% over the past two decades;and the provinces with the highest carbon emissions per capita are InnerMongolia,Ningxia,and Shanxi.(2)At the provincial level,we observed that the Human Development Index(HDI),which includes life expectancy,education,and income,has been rising,while Beijing,Shanghai,and Tianjin entered the super-high HDI level before 2008.(3)The entire coupling effect of 30 Chinese provinces has been broadly fortified in the last 20 years,but the growth rate of DCHDI values in 2011-2019 has slowed down compared with that in 2000-2010;the clustering phenomenon demonstrated that this discovery is associated with historical peaks in total carbon emissions.(4)The co-ordination degree of carbon emissions per capita and HDI was verified,and 96% of the data points were found in the range of super high coupling coordination ***,this study provides the government with worthwhile guidance for decision-making and carbon reduction strategies for other countries struggling to advance human sustainable development.

关键词： Energy-related carbon emissions Human sustainable development DCHDI model Coupling effect Chinese provinces

Effect of Mn Addition and Heat Treatment on the Corrosion Behaviour of Mg-Ag-Mn Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 665-677页

作者： You lv Yupeng Zhang Xi Liu Zehua Dong Xiaorong Zhou Xinxin Zhang Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of EducationHubei Key Laboratory of Material Chemistry and Service FailureSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074China Hubei Engineering Research Centre for Biomaterials and Medical Protective Materials Huazhong University of Science and TechnologyWuhan430074China Corrosion and Protection Centre Department of MaterialsThe University of ManchesterManchesterM139PLUK

The high corrosion sensitivity and the potential bio-toxicity of Mg-Ag alloys limit their wide applications for the production of implanted devices. In the present work, Mn is added into the Mg-Ag alloy to optimize its corrosion behaviour. The corrosion behaviour of Mg-Ag-Mn alloys is investigated with the underlying microstructural factors examined. The Mg-Ag alloy with 2 wt% Mn exhibits the highest corrosion resistance after post-casting heat treatment at 440 ℃. The addition of Mn results in α-Mn phase with the incorporation of Fe, which suppresses the cathodic activity of impurity Fe. Further, heat treatment of the cast alloys homogenizes the distribution of Ag and promotes the precipitation of α-Mn phase. The former removes Ag segregations as potential cathodes;the latter promotes a more uniform distribution of cathodes and, therefore, prevents localized corrosion.

关键词： Mg-Ag alloy Mn addition Post-casting heat treatment Cathodic activity Corrosion mechanism

H-hop independently submodular maximization problem with curvature

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High-Confidence Computing

High-Confidence Computing 2024年第3期4卷 75-81页

作者： Yang lv Chenchen Wu Dachuan Xu Ruiqi Yang Beijing Institute for Scientific and Engineering Computing Beijing University of TechnologyBeijing 100124China College of Science Tianjin University of TechnologyTianjin 300382China

The Connected Sensor Problem(CSP)presents a prevalent challenge in the realms of communication and Internet of Things(IoT)*** primary aim is to maximize the coverage of users while maintaining connectivity among K *** the challenge of managing a large user base alongside a finite number of candidate locations,this paper proposes an extension to the CSP:the h-hop independently submodular maximization problem characterized by curvatureα.We have developed an approximation algorithm that achieves a ratio of 1−e−α/(2h+3)α.The efficacy of this algorithm is demonstrated on the CSP,where it shows superior performance over existing algorithms,marked by an average enhancement of 8.4%.

关键词： Internet of things UAV communication Approximation algorithms

PHLDA2 reshapes the immune microenvironment and induces drug resistance in hepatocellular carcinoma

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Oncology Research 2024年第6期32卷 1063-1078页

作者： KUN FEng HAO PEng QIngPEng lv YEWEI ZHAng Hepatopancreatobiliary Center The Second Affiliated Hospital of Nanjing Medical UniversityNanjing210000China Medical School Southeast UniversityNanjing210000China

Hepatocellular carcinoma(HCC)is a malignancy known for its unfavorable *** dysregulation of the tumor microenvironment(TME)can affect the sensitivity to immunotherapy or chemotherapy,leading to treatment *** elucidation of PHLDA2’s involvement in HCC is imperative,and the clinical value of PHLDA2 is also ***,bioinformatics analysis was performed in multiple cohorts to explore the phenotype and mechanism through which PHLDA2 may affect the progression of ***,the expression and function of PHLDA2 were examined via the qRT-PCR,Western Blot,and MTT *** findings indicate a substantial upregulation of PHLDA2 in HCC,correlated with a poorer *** methylation levels of PHLDA2 were found to be lower in HCC tissues compared to normal liver ***,noteworthy associations were observed between PHLDA2 expression and immune infiltration in *** addition,PHLDA2 upregulation is closely associated with stemness features and immunotherapy or chemotherapy resistance in *** vitro experiments showed that sorafenib or cisplatin significantly up-regulated PHLDA2 mRNA levels,and PHLDA2 knockdown markedly decreased the sensitivity of HCC cells to chemotherapy ***,we found that TGF-βinduced the expression of PHLDA2 in *** GSEA and in vitro experiment indicated that PHLDA2 may promote the HCC progression via activating the AKT signaling *** study revealed the novel role of PHLDA2 as an independent prognostic factor,which plays an essential role in TME remodeling and treatment resistance in HCC.

关键词： HCC Immune infiltration Drug resistance TME PHLDA2

An Improved Harris Hawk Optimization Algorithm for Flexible Job Shop Scheduling Problem

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Computers, Materials & Continua 2024年第2期78卷 2337-2360页

作者： Zhaolin lv Yuexia Zhao Hongyue Kang Zhenyu Gao Yuhang Qin College of Systems Engineering National University of Defense TechnologyChangsha410073China College of Information Management Nanjing Agricultural UniversityNanjing210031China Department of Intelligent Supply Chain JD LogisticsBeijing100076China College of Intelligent Science and Technology National University of Defense TechnologyChangsha410073China

Flexible job shop scheduling problem(FJSP)is the core decision-making problem of intelligent manufacturing production *** Harris hawk optimization(HHO)algorithm,as a typical metaheuristic algorithm,has been widely employed to solve scheduling ***,HHO suffers from premature convergence when solving NP-hard ***,this paper proposes an improved HHO algorithm(GNHHO)to solve the *** introduces an elitism strategy,a chaotic mechanism,a nonlinear escaping energy update strategy,and a Gaussian random walk strategy to prevent premature convergence.A flexible job shop scheduling model is constructed,and the static and dynamic FJSP is investigated to minimize the *** paper chooses a two-segment encoding mode based on the job and the machine of the *** verify the effectiveness of GNHHO,this study tests it in 23 benchmark functions,10 standard job shop scheduling problems(JSPs),and 5 standard ***,this study collects data from an agricultural company and uses the GNHHO algorithm to optimize the company’s *** optimized scheduling scheme demonstrates significant improvements in makespan,with an advancement of 28.16%for static scheduling and 35.63%for dynamic ***,it achieves an average increase of 21.50%in the on-time order delivery *** results demonstrate that the performance of the GNHHO algorithm in solving FJSP is superior to some existing algorithms.

关键词： Flexible job shop scheduling improved Harris hawk optimization algorithm(GNHHO) premature convergence maximum completion time(makespan)

Bifurcation analysis of a diffusive predator-prey model with hyperbolic mortality and prey-taxis

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International Journal of Biomathematics 2024年第1期17卷 251-264页

作者： Yan Li Zhiyi lv Fengrong Zhang Hui Hao College of Science China University of Petroleum(East China)Qingdao 266580P.R.China

In this paper,we study a diffusive predator-prey model with hyperbolic mortality and prey-taxis under homogeneous Neumann boundary *** first analyze the influence of prey-taxis on the local stability of constant *** turns out that prey-taxis has influence on the stability of the unique positive constant equilibrium,but has no influence on the stability of the trivial equilibrium and the semi-trivial *** then derive Hopf bifurcation and steady state bifurcation related to prey-taxis,which imply that the prey-taxis plays an important role in the dynamics.

关键词： Predator-prey model prey-taxis Hopf bifurcation steady state bifurcation