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含稀土氧化物添加剂的AgNi电触头材料的组织及性能研究

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电工材料 2024年第4期 37-40页

作者：谢晓宇黄锡文莫培松徐玮泽蒙建洲李镇鹏桂林金格电工电子材料科技有限公司广西桂林541004

制备了含稀土氧化物(ReO)添加剂的AgNi电触头材料AgNi(15)ReO,对其相结构、添加剂均匀性、金相组织、物理性能等进行分析。结果表明:所制备的材料稀土元素在Ag基体中分散均匀,金相组织无明显缺陷、无添加剂聚集,ReO添加量在1%时电寿命最... 详细信息

制备了含稀土氧化物(ReO)添加剂的AgNi电触头材料AgNi(15)ReO,对其相结构、添加剂均匀性、金相组织、物理性能等进行分析。结果表明:所制备的材料稀土元素在Ag基体中分散均匀,金相组织无明显缺陷、无添加剂聚集,ReO添加量在1%时电寿命最高,有望应用于中等电流等级低压电器中。

关键词： AgNi 稀土氧化物电触头材料添加剂

Electrocatalytic coupling of anodic nitrogen oxidation and cathodic nitrate reduction for ammonia synthesis from air and water

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Nano Research 2024年第9期17卷 7824-7829页

作者： Aijing Ma jianzhou Gui Yanmei Huang Yifu Yu State Key Laboratory of Separation Membranes and Membrane Processes Tianjin Key Laboratory of Green Chemical Technology and Process EngineeringSchool of Chemical Engineering and TechnologyTiangong UniversityTianjin 300387China Institute of Molecular Plus School of Chemical EngineeringTianjin UniversityTianjin 300072China

Ammonia plays a vital role in present agriculture and industry,and is also regarded as a next-generation clean energy *** development of electrocatalysis raises an opportunity to make ammonia synthesis compatible with intermittent and variable renewable energy sources such as solar and wind ***,the direct ammonia electrosynthesis from N_(2)reduction is still challenging due to the much easier hydrogen evolution competition *** this perspective,we propose a novel strategy for ammonia electrosynthesis from air and water based on the coupling of anodic nitrogen oxidation and cathodic nitrate *** methods for breaking the bottlenecks of anodic nitrogen oxidation and cathodic nitrate reduction are discussed *** that,key issues that need to be considered in the coupled system are proposed for the application of this strategy.

关键词： electrocatalysis nitrogen oxidation nitrate reduction nitrogen fixation ammonia synthesis

Exploring diurnal and seasonal variabilities in surface urban heat island intensity in the Guangdong-Hong Kong-Macao Greater Bay Area

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Journal of Geographical Sciences 2024年第8期34卷 1472-1492页

作者： XU Xianjiong WU Yaowei LIN Gangte GONG jianzhou CHEN Kanglin School of Geography and Remote Sensing Guangzhou UniversityGuangzhou 510006China

The urban heat island(UHI) is an environmental problem of wide concern because it poses a threat to both the human living environment and the sustainable development of cities. Knowledge of the spatiotemporal characteristics and the driving factors of UHI is essential for mitigating their impact. However, current understanding of the UHI in the Guangdong–Hong Kong–Macao Greater Bay Area(GBA) is inadequate. Combined with data(e.g., land surface temperature and land use.) acquired from the Google Earth Engine and other sources for the period 2001–2020, this study examined the diurnal and seasonal variabilities, spatial heterogeneities, temporal trends, and drivers of surface UHI intensity(SUHII) in the GBA. The SUHII was calculated based on the urban–rural dichotomy, which has been proven an effective method. The average SUHII was generally 0–2°C, and the SUHII in daytime was generally greater than that at night. The maximum(minimum) SUHII was found in summer(winter);similarly, the largest(smallest) diurnal difference in SUHII was during summer(winter). Generally, the Mann–Kendall trend test and the Sen's slope estimator revealed a statistically insignificant upward trend in SUHII on all time scales. The influence of driving factors on SUHII was examined using the Geo-Detector model. It was found that the number of continuous impervious pixels had the greatest impact, and that the urban–rural difference in the enhanced vegetation index had the smallest impact, suggesting that anthropogenic heat emissions and urban size are the main influencing factors. Thus, controlling urban expansion and reducing anthropogenic heat generation are effective approaches for alleviating surface UHI.

关键词： surface urban heat island spatiotemporal pattern driving forces urban size anthropogenic heat emissions Guangdong-Hong Kong-Macao Greater Bay Area

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

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

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