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Vibration properties of Paulownia wood for Ruan sound quality using machine learning methods

Journal of forestry Research 2024年第5期35卷 216-222页

作者： yang yang College of Art and Design Harbin UniversityHarbin 150076People’s Republic of China College of Mechanical and Electrical Engineering Northeast Forestry UniversityHarbin 150040People’s Republic of China

As an important material for manufacturing resonant components of musical instruments,Paulownia has an important influence on the sound quality of *** this paper,a model for evaluating the sound quality of Ruan based on the vibration characteristics of wood is developed using machine learning ***,the selection of materials for Ruan manufacturing relies primarily on manually weighing,observing,striking,and listening by the instrument *** in scientific theory have hindered the quality of the finished *** this study,nine Ruans were manufactured,and a prediction model of Ruan sound quality was proposed based on the raw material information of *** of a total of 180 data sets,145 and 45 sets were chosen for training and validation,*** this paper,typical correlation analysis was used to determine the correlation between two single indicators in two adjacent pairwise combinations of the measured objects in each stage of the production process in *** vibra-tion characteristics of the wood were tested,and a model for predicting the evaluation of Ruan’s acoustic qualities was developed by measuring the vibration characteristics of the resonating plate *** acoustic quality of the Ruan sound board wood was evaluated and predicted using machine learning model generalized regression neural *** results show that the prediction of Ruan sound quality can be achieved using Matlab simulation based on the vibration characteristics of the soundboard *** the model-predicted values were compared with the tradi-tional predicted results,it was found that the generalized regression neural network had good performance,achieving an accuracy of 93.8%which was highly consistent with the experimental *** was concluded that the model can accurately predict the acoustic quality of the Ruan based on the vibration performance of the soundboards.

关键词： Sound quality Wood vibration performance Paulownia wood Machine learning methods

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Overview of radar detection methods for low altitude targets in marine environments

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Journal of Systems Engineering and Electronics 2024年第1期35卷 1-13页

作者： yang Yong yang Boyu School of Electronic Science National University of Defense TechnologyChangsha 410073China

In this paper,a comprehensive overview of radar detection methods for low-altitude targets in maritime environments is presented,focusing on the challenges posed by sea clutter and multipath *** performance of the radar detection methods under sea clutter,multipath,and combined conditions is categorized and summarized,and future research directions are outlined to enhance radar detection performance for low-altitude targets in maritime environments.

关键词： radar sea clutter multipath scattering detection low altitude target

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fresh-Keeping Decision and Coordination of fresh Agricultural Product Supply Chain Considering Carbon Cap-and-Trade under Different Dominance

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Journal of Systems Science and Systems Engineering 2024年第1期33卷 30-51页

作者： yang yang Guanxin Yao China Institute for Agricultural Equipment Industrial Development Jiangsu UniversityZhenjiang212013China Jiangsu Modern Logistics Research Base Yangzhou UniversityYangzhou225009China

In the context of low carbon,this paper discussed the impact of the carbon cap-and-trade policy on the fresh-keeping decision-making of two-echelon fresh agricultural product supply chains under different dominance,and designed cost-sharing contracts to coordinate the supply chain of fresh agricultural products dominated by suppliers and retailers *** results showed that:dominance has no effect on the fresh-keeping decision and total revenue of fresh agricultural product supply chain,but it affects the internal income distribution,and dominance does not always bring more benefits;the implementation of carbon cap-and-trade reduces the fresh-keeping decision-making of fresh agricultural products supply chain and reduces the free-rider income of followers;the role of higher carbon trading price is twofold,which not only brings about the speculation of leading enterprises,but also promotes the application of low-carbon technologies;consumers’high preference for freshness,low-cost and high-efficiency low-carbon technology are all conducive to improving the fresh-keeping efforts and benefits of the supply chain;cost-sharing contracts can coordinate the supply chain of fresh agricultural products.

关键词： Dominant power carbon cap-and-trade policy fresh agricultural product supply chain fresh-keeping decision-making

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Evaluating transient behaviour of large-scale photovoltaic systems during lightning events using enhanced finite difference time domain method with variable cell size approach

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HIGH VOLTAGE 2024年第3期9卷 636-647页

作者： Hetita, Ibrahim Mansour, Diaa-Eldin A. Han, yang yang, Ping Wang, Congling Darwish, Mohamed M. f. Lehtonen, Matti Zalhaf, Amr S. Univ Elect Sci & Technol China UESTC Sch Mech & Elect Engn Chengdu Peoples R China Helwan Univ Fac Engn Elect Power & Machines Engn Dept Cairo Egypt Tanta Univ Fac Engn Elect Power & Machines Engn Dept Tanta Egypt Egypt Japan Univ Sci & Technol Fac Engn Dept Elect Power Engn Alexandria Egypt Benha Univ Fac Engn Shoubra Dept Elect Engn Cairo Egypt Aalto Univ Sch Elect Engn Dept Elect Engn & Automation Espoo Finland GMC Dept Med Srinagar Jammu And Kashm India

Photovoltaic (PV) arrays are usually installed in open areas; hence, they are vulnerable to lightning strikes that can result in cell degradation, complete damage, service disruption, and increased maintenance costs. As a result, it is imperative to develop an effective and efficient lightning protection system by evaluating the transient behaviour of PV arrays during lightning events. The aim is to evaluate the transient analysis of large-scale PV systems when subjected to lightning strikes using the finite difference time domain (fDTD) technique. Transient overvoltages are calculated at various points within the mounting system. To optimise the fDTD method's execution time and make it more suitable for less powerful hardware, a variable cell size approach is employed. Specifically, larger cell dimensions are used in the earthing system and smaller cell dimensions are used in the mounting system. The fDTD method is utilised to calculate the temporal variation of transient overvoltages for large-scale PV systems under different scenarios, including variations in the striking point, soil resistivity, and the presence of a metal frame. Simulation results indicate that the highest transient overvoltages occur at the striking point, and these values increase with the presence of a PV metal frame as well as with higher soil resistivity. furthermore, a comparison is performed between the overvoltage results obtained from the fDTD approach and the partial element equivalent circuit (PEEC) method at the four corner points of the mounting systems to demonstrate the superior accuracy of the fDTD method. Besides, a laboratory experiment is conducted on a small-scale PV system to validate the simulation results. The calculated overvoltages obtained from the fDTD and PEEC methods are compared with the measured values, yielding a mean absolute error of 5% and 11% for the fDTD and PEEC methods, respectively, thereby confirming the accuracy of the fDTD simulation model.

关键词： fDTD METHOD MODEL

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Layered Potassium Titanium Niobate/Reduced Graphene Oxide Nanocomposite as a Potassium‑Ion Battery Anode

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Nano-Micro Letters 2024年第1期16卷 1-16页

作者： Charlie A.f.Nason Ajay Piriya Vijaya Kumar Saroja Yi Lu Runzhe Wei Yupei Han yang xu Department of Chemistry University College London20 Gordon StreetLondon WC1H 0AJUK

With graphite currently leading as the most viable anode for potassium-ion batteries(KIBs),other materials have been left relatively *** metal oxides are among these,with many positive attributes such as synthetic maturity,longterm cycling stability and fast redox ***,to address this research deficiency we report herein a layered potassium titanium niobate KTiNbO5(KTNO)and its rGO nanocomposite(KTNO/rGO)synthesised via solvothermal methods as a high-performance anode for *** effective distribution across the electrically conductive rGO,the electrochemical performance of the KTNO nanoparticles was *** potassium storage performance of the KTNO/rGO was demonstrated by its first charge capacity of 128.1 mAh g^(−1) and reversible capacity of 97.5 mAh g^(−1) after 500 cycles at 20 mA g^(−1),retaining 76.1%of the initial capacity,with an exceptional rate performance of 54.2 mAh g^(−1)at 1 A g^(−1).furthermore,to investigate the attributes of KTNO in-situ xRD was performed,indicating a low-strain ***-situ x-ray photoelectron spectra further investigated the mechanism of charge storage,with the titanium showing greater redox reversibility than the *** work suggests this lowstrain nature is a highly advantageous property and well worth regarding KTNO as a promising anode for future high-performance KIBs.

关键词： Potassium-ion batteries Intercalation Transition metal oxides Anodes Nanocomposite

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Leptin Modulates the Differentiation of Keratinocytes via Autophagy in Psoriasis Patients with Metabolic Syndrome

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International Journal of Dermatology and Venereology 2024年第3期7卷 121-130页

作者： Song C.-H. Wang R. Zhao Z.-K. Zhang Y. Sun J. Zhang x. Ding x.-Y. Bai J. Liang x.-Q. Wei x.-J. Liu x.-L. yang T. Liang x.-L. Li C.-x. Lin B.-W. Department of Dermatology PLA General Hospital Beijing 100853 China Department of Clinical Laboratory PLA General Hospital Beijing 100853 China Department of Dermatology Southern Medical University Guangdong Guangzhou 510515 China

Objective: Psoriasis is associated with a high prevalence of metabolic syndrome (MS), and patients with concomitant psoriasis and MS are more severely affected and less responsive to treatment. However, the molecular mechanisms behind these effects are unknown. Recent studies have shown that leptin may serve as a molecular link between psoriasis and MS, suggesting that high leptin concentrations may exacerbate psoriasis. However, the molecular mechanism of this effect is still unclear. We aimed to investigate the effect of leptin on autophagy in patients with psoriasis. Methods: from January 2021 to June 2022 in PLA General Hospital, we enrolled 51 patients with psoriasis, including 21 patients with MS and 30 without MS, and 30 healthy controls who had undergone nevus surgery. We measured the epidermal leptin, P62, and LC3B concentrations of patients by immunohistochemistry, and measured the serum leptin concentration by enzyme-linked immunosorbent assay. We then performed correlation analyses to compare these proteins' concentrations between patients with concomitant psoriasis and MS, patients with psoriasis alone, and healthy control groups. Additionally, we performed western blotting after in vitro culture of HaCaT cells with different concentrations of leptin and measured the expression levels of the autophagy markers Beclin1, LC3B, and P62; the differentiation markers K10, K16, and K17; and PI3K/AKT/mTOR signaling pathway-related proteins of HaCat cells. Next, we transfected ATG5 into HaCaT cells to revert autophagy and used the specific PI3K inhibitor LY294002 to block PI3K/AKT/mTOR signaling. The expression levels of K10, K16, and K17 of HaCat cells were again measured. One-way analysis of variance was used for the comparison of means of multiple samples, and LSD-t post hoc test was used for comparison between the 2 groups. The counting data were analyzed by the chi-square test. Correlations were evaluated by Pearson correlation analysis. Results: The serum l

关键词： autophagy keratinocyte differentiation leptin metabolic syndrome PI3K/AKT/mTOR psoriasis signal pathway

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Selective nano-buckling improves the performance of graphene logic transistors

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National Science Review 2024年第2期11卷 95-96页

作者： Tong yang Ming yang Department of Applied Physics The Hong Kong Polytechnic University Research Centre for Nanoscience and Nanotechnology The Hong Kong Polytechnic University

The massive integration of silicon-based transistors into modern electronic devices greatly increases power consumption and heat generation/dissipation[1]. In this concern, transistors based on atomically-thin graphene that exhibit high electric and thermoelectric conductivities with negligible contact resistance,

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In situ digital testing method for quality assessment of soft soil improvement with polyurethane

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1732-1748页

作者： x.f.Wang C.J.Wang W.V.Yue Z.J.Zhang Z.Q.Yue Department of Civil Engineering China University of Geosciences (Beijing)BeijingChina Department of Water Science and Engineering Zhengzhou UniversityZhengzhouChina Department of Geotechnical Engineering Tongji UniversityShanghaiChina Department of Civil Engineering The University of Hong KongChina

This study purposes an in situ testing method on quality assessment of soil *** drilling data includes the spatial distribution and in situ strength of untreated and treated soil along three different drillholes measured by on-site drilling monitoring *** factual drilling data can characterize the degree of soil improvement by penetration injection with permeable *** from on-site drilling monitoring shows that the linear zones represent constant drilling speeds shown in the plot of drill bit advancement *** drilling time,which indicates the spatial distributions of soil *** soil profile at the study site is composed of four layers,which includes fill,untreated silty clay,treated silty clay,and mucky *** results of soil profile are verified by the parallel site *** constant drilling speeds profile the coring-resistant strength of drilled *** comparing with the untreated silty clay,the constant drilling speeds of the treated silty clay have been decreased by 13.0-62.8%.Two drilling-speed-based indices of 61.2%and 65.6%are proposed to assess the decreased average drilling speed and the increased in situ strength of treated silty *** tests,*** compressive strength(UCS)test,have been performed with core sample to investigate and characterize in situ strength by comparing that with drilling *** show that the average predicted strengths of treated silty clay are 2.4-6.9 times higher than the average measured strength of untreated silty *** UCS-based indices of 374.5%and 344.2%verified the quality assessment(QA)results by this new in situ *** method provides a cost-effective tool for quality assessment of soil improvement by utilizing the digital drilling data.

关键词： Drilling process monitoring system Hydraulic rotary drilling process Constant drilling speed Soil improvement Quality assessment

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Design Optimization and Operating Performance of S-CO_(2) Brayton Cycle under fluctuating Ambient Temperature and Diverse Power Demand Scenarios

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Journal of Thermal Science 2024年第1期33卷 190-206页

作者： yang Jingze yang Zhen DUAN Yuanyuan Key Laboratory for Thermal Science and Power Engineering of MOE Beijing Key Laboratory for CO_(2) Utilization and Reduction TechnologyTsinghua UniversityBeijing 100084China

The supercritical CO_(2)(S-CO_(2)) Brayton cycle is expected to replace steam cycle in the application of solar power tower system due to the attractive potential to improve efficiency and reduce *** the concentrated solar power plant with thermal energy storage is usually located in drought area and used to provide a dispatchable power output,the S-CO_(2) Brayton cycle has to operate under fluctuating ambient temperature and diverse power demand *** addition,the cycle design condition will directly affect the off-design *** this work,the combined effects of design condition,and distributions of ambient temperature and power demand on the cycle operating performance are analyzed,and the off-design performance maps are proposed for the first time.A cycle design method with feedback mechanism of operating performance under varied ambient temperature and power demand is introduced *** show that the low design value of compressor inlet temperature is not conductive to efficient operation under low loads and sufficient output under high ambient *** average yearly efficiency is most affected by the average power demand,while the load cover factor is significantly influenced by the average ambient *** multi-objective optimization,the optimal solution of designed compressor inlet temperature is close to the minimum value of35℃ in Delingha with low ambient temperature,while reaches 44.15℃ in Daggett under the scenario of high ambient temperature,low average power demand,long duration and large value of peak load during the peak temperature *** the cycle designed with compressor inlet temperature of 35℃ instead of 44.15℃ in Daggett under light industry power demand,the reduction of load cover factor will reach 0.027,but the average yearly efficiency can barely be improved.

关键词： supercritical CO_(2)Brayton cycle ambient temperature fluctuating power demand scenarios design optimization off-design performance

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A physics-informed deep learning framework for spacecraft pursuit-evasion task assessment

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Chinese Journal of Aeronautics 2024年第5期37卷 363-376页

作者： fuyunxiang yang Leping yang Yanwei ZHU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

Qualitative spacecraft pursuit-evasion problem which focuses on feasibility is rarely studied because of high-dimensional dynamics,intractable terminal constraints and heavy computational *** this paper,A physics-informed framework is proposed for the problem,providing an intuitive method for spacecraft threat relationship determination,situation assessment,mission feasibility analysis and orbital game rules *** the first time,situation adjustment suggestions can be provided for the weak player in orbital ***,a dimension-reduction dynamics is derived in the line-of-sight rotation coordinate system and the qualitative model is determined,reducing complexity and avoiding the difficulty of target set presentation caused by individual ***,the Backwards Reachable Set(BRS)of the target set is used for state space partition and capture zone ***-time analysis can eliminate the influence of changeable initial state and enable the proposed framework to analyze plural situations ***,a time-dependent Hamilton-Jacobi-Isaacs(HJI)Partial Differential Equation(PDE)is established to describe BRS evolution driven by dimension-reduction dynamics,based on level set ***,Physics-Informed Neural Networks(PINNs)are extended to HJI PDE final value problem,supporting orbital game rules summarization through capture zone evolution ***,numerical results demonstrate the feasibility and efficiency of the proposed framework.

关键词： Spacecraft pursuit-evasion Qualitative differential game Physics-Informed Neural Networks(PINNs) Reachability analysis Hamilton-Jacobi-Isaacs(HJI) Partial Differential Equations(PDEs)

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