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A Generative Adversarial Network with an Attention Spatiotemporal Mechanism for Tropical Cyclone Forecasts

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Advances in Atmospheric Sciences 2025年第1期42卷 67-78页

作者： Xiaohui li Xinhai han Jingsong YANG Jiuke WANG Guoqi han Jun DING Hui shen Jun YAN Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200240China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China School of Artificial Intelligence Sun Yat-sen UniversityZhuhai 519082China Fisheries and Oceans Canada Institute of Ocean SciencesSidney V8L 4B2Canada Zhejiang Marine Monitoring and Forecasting Center Hangzhou 310007China

Tropical cyclones(TCs)are complex and powerful weather systems,and accurately forecasting their path,structure,and intensity remains a critical focus and challenge in meteorological *** this paper,we propose an Attention Spatio-Temporal predictive Generative Adversarial Network(AST-GAN)model for predicting the temporal and spatial distribution of *** model forecasts the spatial distribution of TC wind speeds for the next 15 hours at 3-hour intervals,emphasizing the cyclone's center,high wind-speed areas,and its asymmetric *** effectively capture spatiotemporal feature transfer at different time steps,we employ a channel attention mechanism for feature selection,enhancing model performance and reducing parameter *** utilized High-Resolution Weather Research and Forecasting(HWRF)data to train our model,allowing it to assimilate a wide range of TC motion *** model is versatile and can be applied to various complex scenarios,such as multiple TCs moving simultaneously or TCs approaching *** proposed model demonstrates superior forecasting performance,achieving a root-mean-square error(RMSE)of 0.71 m s^(-1)for overall wind speed and 2.74 m s^(-1)for maximum wind speed when benchmarked against ground truth data from ***,the model underwent optimization and independent testing using ERA5reanalysis data,showcasing its stability and *** fine-tuning on the ERA5 dataset,the model achieved an RMSE of 1.33 m s^(-1)for wind speed and 1.75 m s^(-1)for maximum wind *** AST-GAN model outperforms other state-of-the-art models in RMSE on both the HWRF and ERA5 datasets,maintaining its superior performance and demonstrating its effectiveness for spatiotemporal prediction of TCs.

关键词： tropical cyclones spatiotemporal prediction generative adversarial network attention spatiotemporal mechanism deep learning

Smoke and NO_(x)emission characteristics of in-use construction machinery base on substantial field measurement:A case study in Beijing,China

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Journal of Environmental Sciences 2025年第3期149卷 386-393页

作者： Huawei Yi Yangyang Cui lijun Zhu Yan shen han li Guanghan Huang linzhen Qu Dongdong Guo Lei Nie Yifeng Xue National Engineering Research Center of Urban Environmental Pollution Control Beijing Municipal Research Institute of Eco-Environmental ProtectionBeijing 100037China Beijing Vehicle Emission Management Affairs Centre Beijing 100176China

To understand the smoke level and NO_(x)emission characteristics of in-use construction machinery in Beijing,we selected 905 construction machines in Beijing from August 2022 to April 2023 to monitor the emission level of smoke and NO_(x).The exhaust smoke level and excessive emission situation of different machinery types were identified,and their NO_(x)emission levels were monitored according to the free acceleration *** investigated the correlation of NO_(x)and smoke emission,and proposed suggestions for controlling pollution discharge from construction machinery in the *** results show that the exhaust smoke level was 0–2.62 m^(−1),followed a log-normal distribution(μ=-1.73,δ=1.09,R^(2)=0.99),with a 5.64%exceedance *** observed amongmachinery types,with low-power engine forklifts showing higher smoke *** NO_(x)emission range was 71–1516 ppm,followed a normal distribution(μ=565.54,δ=309.51,R^(2)=0.83).Differences among machinery types were relatively *** rated net power had the most significant impact on NO_(x)***,NO_(x)emissions from construction machinery need further ***,we found a weak negative correlation(p<0.05)between the emission level of smoke and NO_(x),that is the synergic emission reduction effect is poor,emphasizing the need for NO_(x)emission *** the future,the oversight in Beijing should prioritize phasing out ChinaⅠand ChinaⅡmachinery,and monitor emissions from highpower engine ChinaⅢmachinery.

关键词： Fuel-oil construction machinery Smoke NO_(x) Emission level Regulatory suggestion

Advances in flexible weak-light detectors based on perovskites:preparation,optimization,and application

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Journal of Semiconductors 2025年第1期46卷 144-164页

作者： Yaqian Yang Ying li Di Chen Guozhen shen School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China

Photodetectors with weak-light detection capabilities play an indispensable role in various crucial fields such as health monitors,imaging,optical communication,and ***,the detection of weak light signals is often severely interfered by multiple factors such as background light,dark noise and circuit noise,making it difficult to accurately capture *** traditional technologies like silicon photomultiplier tubes excel in sensitivity,their high cost and inherent fragility restrict their widespread *** this background,perovskite materials have rapidly emerged as a research focus in the field of photodetection due to their simple preparation processes and exceptional optoelectronic *** only are the preparation processes of perovskite materials straightforward and cost-effective,but more importantly,they can be flexibly integrated into flexible and stretchable *** characteristic significantly compensates for the shortcomings of traditional rigid electronic devices in specific application scenarios,opening up entirely new possibilities for photodetection ***,recent advances in perovskite light detection technology are ***,the chemical and physical properties of perovskite materials are discussed,highlighting their remarkable advantages in weak-light ***,the review systematically organizes various preparation techniques of perovskite materials and analyses their advantages in different application ***,from the two core dimensions of performance improvement and light absorption enhancement,the key strategies of improving the performance of perovskite weak-light photodetectors are ***,the review concludes with a brief summary and a discussion on the potential challenges that may arise in the further development of perovskite devices.

关键词： perovskite weak-light photodetector flexible

Fractal autoencoder with redundancy regularization for unsupervised feature selection

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Science China(Information Sciences) 2025年第2期68卷 89-102页

作者： Meiting SUN Fangyu li Honggui han School of Information Science and Technology Beijing University of Technology Beijing Key Laboratory of Computational Intelligence and Intelligent System Engineering Research Center of Digital Community Ministry of Education Beijing Institute of Artificial Intelligence

Feature selection is a crucial step in data preprocessing because feature selection reduces the dimensionality of data by eliminating irrelevant and redundant features. Since manual labeling is expensive, unsupervised feature selection has received increasing attention in recent years. However, existing unsupervised feature selection methods tend to prioritize selecting highly correlated features over exploring feature diversity. Thus, a regularized fractal autoencoder(RFAE) method is proposed to select informative features in an unsupervised way. Specifically, the fractal autoencoder network extends autoencoders to construct a correspondence neural network and a selection neural network. The correspondence neural network exploits interfeature correlations and the selection neural network selects the informative features. A redundancy regularization strategy consists of a redundancy elimination regularization term based on the dependency between features and a sparse regularization term based on the group lasso. The redundancy regularization strategy eliminates feature subset redundancy and enhances network generalization ability. Extensive experimental results on six publicly available datasets show that the proposed RFAE outperforms the compared methods regarding clustering accuracy and classification accuracy. Moreover, the proposed RFAE achieves acceptable computation efficiency.

关键词： unsupervised feature selection fractal autoencoder correspondence neural network selection neural network redundancy regularization strategy

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Spatial differentiation of carbon emissions from energy consumption based on machine learning algorithm:A case study during 2015–2020 in Shaanxi,China

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Journal of Environmental Sciences 2025年第3期149卷 358-373页

作者： Hongye Cao ling han Ming liu liangzhi li China Jikan Research Institute of Engineering Investigations and Design Co.Ltd.Xi’an 710043China College of Geological Engineering and Geomatics Chang’an UniversityXi’an 710061China School of Land Engineering Chang’an UniversityXi’an 710064China Xi’an Key Laboratory of Territorial Spatial Information School of Land EngineeringChang’an UniversityXi’an 710064China Department of Geography and Environmental Management University of WaterlooWaterlooOntario N2L 3G1Canada

Carbon emissions resulting from energy consumption have become a pressing issue for governments *** estimation of carbon emissions using satellite remote sensing data has become a crucial research *** studies relied on statistical regression models that failed to capture the complex nonlinear relationships between carbon emissions and characteristic *** this study,we propose a machine learning algorithm for carbon emissions,a Bayesian optimized XGboost regression model,using multi-year energy carbon emission data and nighttime lights(NTL)remote sensing data from Shaanxi Province,*** results demonstrate that the XGboost algorithm outperforms linear regression and four other machine learning models,with an R^(2)of 0.906 and RMSE of *** observe an annual increase in carbon emissions,with high-emission counties primarily concentrated in northern and central Shaanxi Province,displaying a shift from discrete,sporadic points to contiguous,extended spatial *** autocorrelation clustering reveals predominantly high-high and low-low clustering patterns,with economically developed counties showing high-emission clustering and economically relatively backward counties displaying low-emission *** findings show that the use of NTL data and the XGboost algorithm can estimate and predict carbon emissionsmore accurately and provide a complementary reference for satellite remote sensing image data to serve carbon emission monitoring and *** research provides an important theoretical basis for formulating practical carbon emission reduction policies and contributes to the development of techniques for accurate carbon emission estimation using remote sensing data.

关键词： Machine learning Energy carbon emissions Nighttime light Spatial distribution

Trifluoromethylative homo-coupling of carbonyl compounds

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Chinese Chemical Letters 2025年第1期36卷 283-287页

作者： Xinlong han Huiying Zeng Chao-Jun li The State Key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhou 730000China Department of Chemistry FQRNT Centre for Green Chemistry and CatalysisMcGill UniversityMontrealQuebecH3A 0B8Canada

Carbonyl compounds are abundant in nature and represent a substantial portion of biomass *** significant recent progress in homo-coupling of carbonyl compounds,achieving their deoxyfunctionalization homo-coupling remains a highly intricate ***,we report an entirely novel reaction paradigm:the trifluoromethylative homo-coupling of carbonyl compounds via hydrazones,which enables the formation of three C(sp^(3))-C(sp^(3))bonds in a single *** method provides a new pathway for synthesizing trifluoromethylative coupling product which has unique applications in both fields of medical and material *** investigations have unveiled that the formation of a trifluoromethyl-substituted benzyl radical plays a pivotal role as a key intermediate in this reaction.

关键词： Carbonyl compounds Trifluoromethylation Homo-coupling C(sp^(3))-C(sp^(3))bond formation

Numerical Analysis of Urban-Rail Vehicle/Tunnel Aerodynamic Interaction

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Fluid Dynamics & Materials Processing 2025年第1期21卷 161-178页

作者： Haoran Meng Nianxun li Xukui shen Hong Zhang Tian li Beijing Infrastructure Investment Co. Ltd.Beijing100101China Beijing Rail Transit Technology Equipment Group Co. Ltd.Beijing100070China Department of Mechanical Engineering Tsinghua UniversityBeijing100084China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China

The pressure wave generated by an urban-rail vehicle when passing through a tunnel affects the comfort of passengersand may even cause damage to the train and related tunnel ***,controlling the trainspeed in the tunnel is extremely *** this study,this problem is investigated numerically in the frameworkof the standard k-εtwo-equation turbulence *** particular,an eight-car urban rail train passingthrough a tunnel at different speeds(140,160,180 and 200 km/h)is *** results show that the maximumaerodynamic drag of the head and tail cars is most affected by the running *** pressure at selectedmeasuring points on the windward side of the head car is very high,and the negative pressure at the side windowof the driver’s cab of the tail car is also very *** the head car to the tail car,the pressure at the same heightgradually *** positive pressure peak at the head car and the negative pressure peak at the tail car aregreatly affected by the speed.

关键词： Urban-rail vehicle vehicle speed aerodynamic force surface pressure numerical simulation

Anomaly monitoring and early warning of electric moped charging device with infrared image

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Optoelectronics Letters 2025年第3期21卷 136-141页

作者： li Jiamin han Bo JIANG Mingshun School of Control Science and Engineering Shandong University

Potential high-temperature risks exist in heat-prone components of electric moped charging devices, such as sockets,interfaces, and controllers. Traditional detection methods have limitations in terms of real-time performance and monitoring scope. To address this, a temperature detection method based on infrared image processing has been proposed:utilizing the median filtering algorithm to denoise the original infrared image, then applying an image segmentation algorithm to divide the image.

关键词： A

Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 102-110页

作者： Qiang liu Xiang li shen Du Ming Gao Yanbin Yin Jiongming Zhang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the *** which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid *** contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive ***,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding *** results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles *** addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually *** one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the *** findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.

关键词： mold flux low basicity bubbles three-dimensional X-ray microscope viscosity