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Hydromechanical characterization of gas transport amidst uncertainty for underground nuclear explosion detection

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2019-2032页

作者： wenfeng Li Chelsea w.Neil J william Carey meng meng Luke P.frash Philip H.Stauffer Earth and Environmental Sciences Los Alamos National LaboratoryLos AlamosNM87544USA Department of Mineral Engineering New Mexico TechSocorroNM87801USA

Given the challenge of definitively discriminating between chemical and nuclear explosions using seismic methods alone,surface detection of signature noble gas radioisotopes is considered a positive identification of underground nuclear explosions(UNEs).However,the migration of signature radionuclide gases between the nuclear cavity and surface is not well understood because complex processes are involved,including the generation of complex fracture networks,reactivation of natural fractures and faults,and thermo-hydro-mechanical-chemical(THMC)coupling of radionuclide gas transport in the *** this study,we provide an experimental investigation of hydro-mechanical(HM)coupling among gas flow,stress states,rock deformation,and rock damage using a unique multi-physics triaxial direct shear rock testing *** testing system also features redundant gas pressure and flow rate measurements,well suited for parameter uncertainty *** porous tuff and tight granite samples that are relevant to historic UNE tests,we measured the Biot effective stress coefficient,rock matrix gas permeability,and fracture gas permeability at a range of pore pressure and stress *** Biot effective stress coefficient varies from 0.69 to 1 for the tuff,whose porosity averages 35.3%±0.7%,while this coefficient varies from 0.51 to 0.78 for the tight granite(porosityffective stress for the granite,but not for the porous *** experiments reveal the following key engineering implications on transport of radionuclide gases post a UNE event:(1)The porous tuff shows apparent fracture dilation or compression upon stress changes,which does not necessarily change the gas permeability;(2)The granite fracture permeability shows strong stress sensitivity and is positively related to shear displacement;and(3)Hydromechanical coupling among stress states,rock damage,and gas flow appears to be

关键词： Underground nuclear explosion uncertainty quantification Radionuclide transport Biot effective stress coefficient fracture permeability Matrix permeability

Species-specific and generalized allometric biomass models for eight fagaceae species in the understory of evergreen broadleaved forests in subtropical China

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Journal of forestry Research 2024年第4期35卷 156-170页

作者： Shengwang meng Qianyanzhou Ecological Research Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101People’s Republic of China

Quantifying the biomass of saplings in the regeneration component is critical for understanding biogeochemical processes of forest ***,accurate allometric equations have yet to be developed in sufficient *** develop species-specific and generalized allometric equations,154 saplings of eight fagaceae tree species in subtropical China’s evergreen broadleaved forests were *** dendrometric variables,root collar diameter(d),height(h),and crown area(ca)were applied in the model by the weighted nonlinear seemingly unrelated regression *** only d as an input variable,the species-specific and generalized allometric equations estimated the aboveground biomass reasonably,with R _(adj)^(2) values generally>*** h and/or ca improved the fitting of some biomass components to a certain *** equations showed a relatively large coefficient of variation but comparable bias to species-specific *** in the absence of species-specific equations at a given location are generalized equations for mixed species *** developed regression equations can be used to accurately calculate the aboveground biomass of understory fagaceae regeneration trees in China’s subtropical evergreen broadleaved forests.

关键词： Allometry Aboveground biomass Additivity Regeneration Subtropical China

Applications of optical control materials based on localized surface plasmon resonance effect in smart windows

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Tungsten 2024年第4期6卷 711-731页

作者： Na Ta Jing-Yi Huang Shuai He w.Hanggai Luo-meng Chao College of Science Inner Mongolia University of Science and Technology fundamental Aspects of Materials and Energy Faculty of Applied Sciences Delft University of Technology

The increasing energy consumption in buildings due to cooling and heating,accounting for over one-third of the total energy consumption in society,has become a growing ***,reducing building energy consumption has become an urgent issue for countries *** serve as the primary channel for energy exchange between the indoor and the outdoor *** providing natural lighting for occupants,windows are also the weakest link in terms of energy *** recent years,there have been some new and superior coating glass technologies compared to traditional low-emissivity *** coatings utilize various optical functional materials to regulate the incident sunlight,aiming to save cooling and heating energy ***,such as tungsten-based compounds,vanadium dioxide,lanthanum hexaboride,or copper monosulfide,can absorb near-infrared light to effectively control solar radiation by leveraging the localized surface plasmon resonance(LSPR) effect of *** paper mainly introduces the micro-mechanisms of these materials and provides a detailed summary of the latest advancements in coating *** application and effects of these coatings in building energy conservation are ***,the challenges and prospects of LSPRbased smart windows are *** is expected that this review will provide new insights into the application of smart windows in green buildings.

关键词： Copper monosulfide Lanthanum hexaboride Localized surface plasmon resonance (LSPR) Tungsten Tungsten-based compounds Vanadium dioxide

A vertical track nonlinear energy sink

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 931-946页

作者： meng LI Hu DING Shanghai Key Laboratory of Mechanics in Energy Engineering School of Mechanics and Engineering ScienceShanghai Frontier Science Center of MechanoinformaticsShanghai UniversityShanghai 200444China

Eliminating the effects of gravity and designing nonlinear energy sinks(NESs)that suppress vibration in the vertical direction is a challenging task with numerous damping *** this paper,the dynamic design of a vertical track nonlinear energy sink(VTNES)with zero linear stiffness in the vertical direction is proposed and realized for the first *** motion differential equations of the VTNES coupled with a linear oscillator(LO)are *** the strong nonlinearity considered of the VTNES,the steady-state response of the system is analyzed with the harmonic balance method(HBM),and the accuracy of the HBM is verified *** this basis,the VTNES prototype is manufactured,and its nonlinear stiffness is *** damping effect and dynamic characteristics of the VTNES are studied theoretically and *** results show that the VTNES has better damping effects when strong modulation responses(SMRs)***,even for small-amplitude vibration,the VTNES also has a good vibration suppression *** sum up,in order to suppress the vertical vibration,an NES is designed and developed,which can suppress the vertical vibration within certain ranges of the resonance frequency and the vibration intensity.

关键词： track nonlinear energy sink(TNES) vertical direction gravity nonlinear stiffness harmonic balance method(HBM) vibration control

Experimental study of corner separation and unsteady characteristics in linear compressor cascades with and without sweeping jet actuator

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Propulsion and Power Research 2024年第3期13卷 360-374页

作者： S.w.Chen w.H.Li C.Xu Q.H.meng School of Energy Science and Engineering Harbin Institute of TechnologyHarbinHeilongjiang 150001China AVIC Shenyang Aircraft Design and Research Institute Shenyang 110035China

Sweeping jet actuator(SJA)has been widely applied for activeflow control in *** this paper,the SJA character in compressor cascade and its performance for separation control in innerflows are ***-averaged and transientflowfield measurement,together with visualization methods are *** is found that endwall effects are important for both SJA behaviors and SJA performance for separation control in compressor *** is a maximum of 12.7%total pressure loss reduction with SJA placed near the separation position,close to the endwall and under *** characteristic frequencies in theflowfield contribute to the capture of influence regions of vortices and excitation *** concentrated shedding vortices and SJA jets impact region helped to judge that SJA energizes low momentumfluids in a large region and matches the high loss core *** be concrete,theflow separation control mechanism of SJA lies on the interruption of the blade suction surface boundary layer development and the restriction of the lifting of the boundary layer from end-wall towards blade suction surface.

关键词： Compressor cascade Activeflow control Sweeping jet actuator Corner separation Oilflow visualization

Nested Saturated Control of Uncertain Complex Cascade Systems Using Mixed Saturation Levels

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1163-1174页

作者： meng Li Zhigang Zeng wuhan National Laboratory for Optoelectronics Wuhan 430074 School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074China School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074 Key Laboratory of Image Processing and Intelligent Control of Education Ministry of China Wuhan 430074China

This study addresses the problem of global asymptotic stability for uncertain complex cascade systems composed of multiple integrator systems and non-strict feedforward nonlinear systems. To tackle the complexity inherent in such structures, a novel nested saturated control design is proposed that incorporates both constant saturation levels and state-dependent saturation levels. Specifically, a modified differentiable saturation function is proposed to facilitate the saturation reduction analysis of the uncertain complex cascade systems under the presence of mixed saturation levels. In addition, the design of modified differentiable saturation function will help to construct a hierarchical global convergence strategy to improve the robustness of control design scheme. Through calculation of relevant inequalities, time derivative of boundary surface and simple Lyapunov function,saturation reduction analysis and convergence analysis are carried out, and then a set of explicit parameter conditions are provided to ensure global asymptotic stability in the closed-loop systems. finally, a simplified system of the mechanical model is presented to validate the effectiveness of the proposed method.

关键词： method saturation differentiable

Adaptive admittance tracking control for interactive robot with prescribed performance

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Journal of Systems Engineering and Electronics 2024年第2期35卷 444-450页

作者： meng Qingrui LIN Yan School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100190China College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China

An adaptive control approach is presented in this paper for tracking desired trajectories in interactive manipulators. The controller design incorporates prescribed performance functions (PPfs) to improve dynamic performance. Notably, the performance of the output error is confined in an envelope characterized by exponential convergence, leading to convergence to zero. This feature ensures a prompt response from admittance control and establishes a reliable safety framework for interactions. Simulation results provide practical insights,demonstrating the viability of the control scheme proposed in this paper.

关键词： prescribed performance admittance control adaptive control robots

Cooperative User-Scheduling and Resource Allocation Optimization for Intelligent Reflecting Surface Enhanced LEO Satellite Communication

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China Communications 2024年第2期21卷 227-244页

作者： meng meng Bo Hu Shanzhi Chen Jianyin Zhang State Key Lab of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Lab of wireless Mobile Communication China Academy of Telecommunication TechnologyBeijing 100191China Research Institute of China Mobile Beijing 100053China

Lower Earth Orbit(LEO) satellite becomes an important part of complementing terrestrial communication due to its lower orbital altitude and smaller propagation delay than Geostationary satellite. However, the LEO satellite communication system cannot meet the requirements of users when the satellite-terrestrial link is blocked by obstacles. To solve this problem, we introduce Intelligent reflect surface(IRS) for improving the achievable rate of terrestrial users in LEO satellite communication. we investigated joint IRS scheduling, user scheduling, power and bandwidth allocation(JIRPB) optimization algorithm for improving LEO satellite system *** optimization problem of joint user scheduling and resource allocation is formulated as a non-convex optimization problem. To cope with this problem, the nonconvex optimization problem is divided into resource allocation optimization sub-problem and scheduling optimization sub-problem firstly. Second, we optimize the resource allocation sub-problem via alternating direction multiplier method(ADMM) and scheduling sub-problem via Lagrangian dual method ***, we prove that the proposed resource allocation algorithm based ADMM approaches sublinear convergence theoretically. finally, we demonstrate that the proposed JIRPB optimization algorithm improves the LEO satellite communication system throughput.

关键词： convex optimization intelligent reflecting surface LEO satellite communication OfDM

Identifying Comprehensive Genomic Alterations and Potential Neoantigens for Cervical Cancer Immunotherapy in a Cohort of Chinese Squamous Cell Carcinoma of the Cervix

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Biomedical and Environmental Sciences 2024年第6期37卷 565-580页

作者： meng wu Jialu Zhou Zhe Zhang Yuanguang meng School of Medicine Nankai UniversityTianjin 300071China Department of Obstetrics and Gynecology The First Medical Center of Chinese PLA General HospitalBeijing 100853China Department of Obstetrics and Gynecology Chinese PLA Medical SchoolBeijing 100853China Department of Obstetrics and Gynecology The Seventh Medical Center of Chinese PLA General HospitalBeijing 100700China

Objective Genomic alterations and potential neoantigens for cervical cancer immunotherapy were identified in a cohort of Chinese patients with cervical squamous cell carcinoma(CSCC).Methods whole-exome sequencing was used to identify genomic alterations and potential neoantigens for CSCC *** Sequencing was performed to analyze neoantigen *** Systematic bioinformatics analysis showed that C>T/G>A transitions/transversions were dominant in *** mutations were the most frequent types of somatic mutation in the coding sequence *** signature analysis detected signature 2,signature 6,and signature 7 in CSCC ***3CA,fBXw7,and BICRA were identified as potential driver genes,with BICRA as a newly reported *** variation profiling identified 4,960 potential neoantigens,of which 114 were listed in two neoantigen-related *** The present findings contribute to our understanding of the genomic characteristics of CSCC and provide a foundation for the development of new biotechnology methods for individualized immunotherapy in CSCC.

关键词： Cervical squamous cell carcinoma Genome alteration Neoantigens Immunotherapy