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Aspect in Topography to Enhance Fine-detailed Landform Element Extraction on High-resolution DEM
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作者 XIE Xiao ZHOU Xiran +4 位作者 XUE Bing XUE Yong QIN Kai LI Jingzhong YANG Jun 《Chinese Geographical Science》 SCIE CSCD 2021年第5期915-930,共16页
The value of the high-resolution data lies in the high-precision information discovery.The fine-detailed landform element extraction is thus the basis of high-fidelity application of the high-resolution digital elevat... The value of the high-resolution data lies in the high-precision information discovery.The fine-detailed landform element extraction is thus the basis of high-fidelity application of the high-resolution digital elevation models(DEMs).However,the results of landform element extraction generated by classical methods might be ungrounded on high-resolution DEMs.This paper presents our research on using the aspect to reinforce the applicability and robustness of the classical approaches in landform element extraction.First,according to the research of pattern recognition,we assume that aspect-enhanced landform representation is robust to rotation,scaling and affine variance.To testify the role of aspect,we respectively integrated the aspect into three classical approaches:mean curvaturebased fuzzy classification,elevation-based feature descriptor,and object-based segmentation.In the experiment,based on four types of high-resolution DEMs(1 m,2 m,4 m and 8 m),we compare each classical approaches and their corresponding aspect-enhanced approaches based on extracting the rims of two craters having different landforms,and the ridgelines and valleylines of a region covered by few vegetables and man-made buildings.In comparison to the results generated by curvature-based fuzzy classification,the aspect enhanced curvature-based fuzzy classification can effectively filter a number of noises outperforms the curvature-based one.Otherwise,the aspect-enhanced feature descriptor can detect more landform elements than the elevation-based feature descriptor.Moreover,the aspect-based segmentation can detect the main structure of landform,while the boundaries segmented by classical approaches are messing and meaningless.The systematic experiments on meter-level resolution DEMs proved that the aspect in topography could effectively to improve the classical method-system,including fuzzy-based classification,feature descriptors-based detection and object-based segmentation.The value of aspect is significantly great to be worthy of attentions in landform representation. 展开更多
关键词 high-resolution dem(digital elevation model) landform representation landform element extraction crater detection aspect granularity aspect-enhanced landform representation America
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An Object-based Approach for Two-level Gully Feature Mapping Using High-resolution DEM and Imagery: A Case Study on Hilly Loess Plateau Region, China 被引量:13
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作者 LIU Kai DING Hu +4 位作者 TANG Guoan ZHU A-Xing YANG Xin JIANG Sheng CAO Jianjun 《Chinese Geographical Science》 SCIE CSCD 2017年第3期415-430,共16页
Gully feature mapping is an indispensable prerequisite for the motioning and control of gully erosion which is a widespread natural hazard. The increasing availability of high-resolution Digital Elevation Model(DEM) a... Gully feature mapping is an indispensable prerequisite for the motioning and control of gully erosion which is a widespread natural hazard. The increasing availability of high-resolution Digital Elevation Model(DEM) and remote sensing imagery, combined with developed object-based methods enables automatic gully feature mapping. But still few studies have specifically focused on gully feature mapping on different scales. In this study, an object-based approach to two-level gully feature mapping, including gully-affected areas and bank gullies, was developed and tested on 1-m DEM and Worldview-3 imagery of a catchment in the Chinese Loess Plateau. The methodology includes a sequence of data preparation, image segmentation, metric calculation, and random forest based classification. The results of the two-level mapping were based on a random forest model after investigating the effects of feature selection and class-imbalance problem. Results show that the segmentation strategy adopted in this paper which considers the topographic information and optimal parameter combination can improve the segmentation results. The distribution of the gully-affected area is closely related to topographic information, however, the spectral features are more dominant for bank gully mapping. The highest overall accuracy of the gully-affected area mapping was 93.06% with four topographic features. The highest overall accuracy of bank gully mapping is 78.5% when all features are adopted. The proposed approach is a creditable option for hierarchical mapping of gully feature information, which is suitable for the application in hily Loess Plateau region. 展开更多
关键词 object-based image analysis gully feature hierarchical mapping gully erosion Digital Elevation Model(dem
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HUANNet: A High-Resolution Unified Attention Network for Accurate Counting
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作者 Haixia Wang Huan Zhang +2 位作者 Xiuling Wang Xule Xin Zhiguo Zhang 《Computers, Materials & Continua》 2026年第1期1722-1741,共20页
Accurately counting dense objects in complex and diverse backgrounds is a significant challenge in computer vision,with applications ranging from crowd counting to various other object counting tasks.To address this,w... Accurately counting dense objects in complex and diverse backgrounds is a significant challenge in computer vision,with applications ranging from crowd counting to various other object counting tasks.To address this,we propose HUANNet(High-Resolution Unified Attention Network),a convolutional neural network designed to capture both local features and rich semantic information through a high-resolution representation learning framework,while optimizing computational distribution across parallel branches.HUANNet introduces three core modules:the High-Resolution Attention Module(HRAM),which enhances feature extraction by optimizing multiresolution feature fusion;the Unified Multi-Scale Attention Module(UMAM),which integrates spatial,channel,and convolutional kernel information through an attention mechanism applied across multiple levels of the network;and the Grid-Assisted Point Matching Module(GPMM),which stabilizes and improves point-to-point matching by leveraging grid-based mechanisms.Extensive experiments show that HUANNet achieves competitive results on the ShanghaiTech Part A/B crowd counting datasets and sets new state-of-the-art performance on dense object counting datasets such as CARPK and XRAY-IECCD,demonstrating the effectiveness and versatility of HUANNet. 展开更多
关键词 Accurate counting high-resolution representations point-to-point matching
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Integrating high-resolution mass spectrometry and transcriptomics to explore the therapeutic mechanism of Sanhuang Oil in diabetic foot
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作者 Ping Sun Yu-Feng Zhang +4 位作者 Shuang Li Wei Zhang Peng-Fei Zhao Chen-Xia Li Chen-Ning Zhang 《Traditional Medicine Research》 2026年第1期19-38,共20页
Background:Diabetic foot,a severe complication of diabetes,is characterized by chronic refractory wounds.Sanhuang Oil,a topical herbal formula,demonstrates significant therapeutic effects including antibacterial,anti-... Background:Diabetic foot,a severe complication of diabetes,is characterized by chronic refractory wounds.Sanhuang Oil,a topical herbal formula,demonstrates significant therapeutic effects including antibacterial,anti-inflammatory,and immunomodulatory activities.However,its active constituents and mechanisms of action against diabetic foot remain to be elucidated.Methods:In this study,the chemical constituents of Sanhuang Oil were identified using UPLC-QE-Orbitrap-MS.Subsequently,the mechanism by which Sanhuang Oil promotes diabetic foot ulcer healing was predicted by integrating network pharmacology and molecular docking.Additionally,diabetic mouse model was established in ICR mice using a combination of a high-fat diet(HFD)and streptozotocin(STZ)chemical induction.A full-thickness skin defect was created on the dorsum of the mice.Wound healing and the healing rate were observed following Sanhuang Oil intervention.The mechanism underlying Sanhuang Oil’s promotion of diabetic ulcer healing was further investigated using transcriptomics and histopathological examination(H&E staining).Results:A total of 97 active ingredients were identified from Sanhuang Oil.Network pharmacology analysis predicted 543 common targets,and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis identified 203 relevant pathways.Molecular docking further confirmed high binding affinity(binding energy≤−5.0 kcal/mol)between specific active components in Sanhuang Oil(e.g.,coptisine,phellodendrine,baicalein)and key targets associated with diabetic foot ulcers(e.g.,EGFR,AKT1,STAT3).In vivo experimental results demonstrated that the wound healing rate was significantly higher in Sanhuang Oil-treated groups compared to the model group(P<0.001).HE staining revealed that the high-dose Sanhuang Oil group exhibited more pronounced epithelial tissue coverage over the wound,reduced inflammatory cell infiltration,and increased collagen deposition and fibroblast proliferation.transcriptomic analysis identified Pdk4,Ttn,Csrp3,Actn2,Myoz2,Tnnc2,Myod1,Myog,Myot,and Myf6 as key regulatory proteins involved in promoting wound healing.Conclusion:Sanhuang Oil promotes wound healing in diabetic ulcer mice,potentially by mitigating inflammation and regulating key targets such as Pdk4 to enhance fibroblast function.These findings provide novel insights into the multi-target,multi-pathway mechanism of Sanhuang Oil for treating diabetic foot ulcers. 展开更多
关键词 Sanhuang Oil diabetic foot high-resolution mass spectrometry molecular network analysis mechanism of action
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Combining machine learning algorithms with traditional methods for resolving the atomic-scale dynamic structure of monolayer MoS_(2) in high-resolution transmission electron microscopy 被引量:1
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作者 Yu Meng Shuya Wang +5 位作者 Xibiao Ren Han Xue Xuejun Yue Chuanhong Jin Shanggang Lin Fang Lin 《Chinese Physics B》 2025年第1期162-170,共9页
High-resolution transmission electron microscopy(HRTEM)promises rapid atomic-scale dynamic structure imaging.Yet,the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-co... High-resolution transmission electron microscopy(HRTEM)promises rapid atomic-scale dynamic structure imaging.Yet,the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-corrected transmission electron microscopy constrain resolution.A machine learning algorithm is developed to determine the aberration parameters with higher precision from small,lattice-periodic crystal images.The proposed algorithm is then validated with simulated HRTEM images of graphene and applied to the experimental images of a molybdenum disulfide(MoS_(2))monolayer with 25 variables(14 aberrations)resolved in wide ranges.Using these measured parameters,the phases of the exit-wave functions are reconstructed for each image in a focal series of MoS_(2)monolayers.The images were acquired due to the unexpected movement of the specimen holder.Four-dimensional data extraction reveals time-varying atomic structures and ripple.In particular,the atomic evolution of the sulfur-vacancy point and line defects,as well as the edge structure near the amorphous,is visualized as the resolution has been improved from about 1.75?to 0.9 A.This method can help salvage important transmission electron microscope images and is beneficial for the images obtained from electron microscopes with average stability. 展开更多
关键词 aberration measurement high-resolution transmission electron microscopy feature-extraction networks exit-wave reconstruction monolayer MoS_(2)
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基于CFD-DEM耦合仿真的气吸式核桃定向摆放装置的设计与试验
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作者 刘梦迪 王应彪 +2 位作者 王周梅 张超宇 李九峰 《中国油脂》 北大核心 2026年第1期122-128,共7页
为确保核桃在吸附摆放过程中的姿态固定,设计一种气吸式核桃定向摆放装置。利用CFD-DEM气固两相耦合仿真方法对核桃定向摆放的工作过程进行分析,以核桃与吸口的距离、气流速度、负压强度为考察因素,定向合格指数为评价指标,采用单因素... 为确保核桃在吸附摆放过程中的姿态固定,设计一种气吸式核桃定向摆放装置。利用CFD-DEM气固两相耦合仿真方法对核桃定向摆放的工作过程进行分析,以核桃与吸口的距离、气流速度、负压强度为考察因素,定向合格指数为评价指标,采用单因素试验和响应面试验对核桃定向摆放装置的工作参数进行仿真优化,并结合实际试验验证定向吸附核桃的可行性。结果表明:核桃能被吸起的最低气流速度为25.5 m/s,最小负压强度为-93.6 kPa;影响定向合格指数的因素依次为气流速度、核桃与吸口的距离、负压强度;通过仿真优化和实际试验验证得到气吸式核桃定向摆放装置的最优工作参数为核桃与吸口的距离4 mm、气流速度27 m/s、负压强度-98 kPa,此时平均定向吸附成功率为95%。综上,气吸式核桃定向摆放装置满足核桃定向吸附摆放生产要求。 展开更多
关键词 核桃 气吸式 定向摆放 CFD-dem
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HRAM-VITON: High-Resolution Virtual Try-On with Attention Mechanism
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作者 Yue Chen Xiaoman Liang +2 位作者 Mugang Lin Fachao Zhang Huihuang Zhao 《Computers, Materials & Continua》 2025年第2期2753-2768,共16页
The objective of image-based virtual try-on is to seamlessly integrate clothing onto a target image, generating a realistic representation of the character in the specified attire. However, existing virtual try-on met... The objective of image-based virtual try-on is to seamlessly integrate clothing onto a target image, generating a realistic representation of the character in the specified attire. However, existing virtual try-on methods frequently encounter challenges, including misalignment between the body and clothing, noticeable artifacts, and the loss of intricate garment details. To overcome these challenges, we introduce a two-stage high-resolution virtual try-on framework that integrates an attention mechanism, comprising a garment warping stage and an image generation stage. During the garment warping stage, we incorporate a channel attention mechanism to effectively retain the critical features of the garment, addressing challenges such as the loss of patterns, colors, and other essential details commonly observed in virtual try-on images produced by existing methods. During the image generation stage, with the aim of maximizing the utilization of the information proffered by the input image, the input features undergo double sampling within the normalization procedure, thereby enhancing the detail fidelity and clothing alignment efficacy of the output image. Experimental evaluations conducted on high-resolution datasets validate the effectiveness of the proposed method. Results demonstrate significant improvements in preserving garment details, reducing artifacts, and achieving superior alignment between the clothing and body compared to baseline methods, establishing its advantage in generating realistic and high-quality virtual try-on images. 展开更多
关键词 Virtual try-on attention mechanism high-resolution image generation
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Fourier neural operator for high-resolution fluid flow simulation based on low-resolution data:the vorticity equation as an example
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作者 Hongchao Qu Xiongbo Zheng +1 位作者 Lihong Yang Zhenya Song 《Acta Oceanologica Sinica》 2025年第6期165-177,共13页
In oceanic and atmospheric science,finer resolutions have become a prevailing trend in all aspects of development.For high-resolution fluid flow simulations,the computational costs of widely used numerical models incr... In oceanic and atmospheric science,finer resolutions have become a prevailing trend in all aspects of development.For high-resolution fluid flow simulations,the computational costs of widely used numerical models increase significantly with the resolution.Artificial intelligence methods have attracted increasing attention because of their high precision and fast computing speeds compared with traditional numerical model methods.The resolution-independent Fourier neural operator(FNO)presents a promising solution to the still challenging problem of high-resolution fluid flow simulations based on low-resolution data.Accordingly,we assess the potential of FNO for high-resolution fluid flow simulations using the vorticity equation as an example.We assess and compare the performance of FNO in multiple high-resolution tests varying the amounts of data and the evolution durations.When assessed with finer resolution data(even up to number of grid points with 1280×1280),the FNO model,trained at low resolution(number of grid points with 64×64)and with limited data,exhibits a stable overall error and good accuracy.Additionally,our work demonstrates that the FNO model takes less time than the traditional numerical method for high-resolution simulations.This suggests that FNO has the prospect of becoming a cost-effective and highly precise model for high-resolution simulations in the future.Moreover,FNO can make longer high-resolution predictions while training with less data by superimposing vorticity fields from previous time steps as input.A suitable initial learning rate can be set according to the frequency principle,and the time intervals of the dataset need to be adjusted according to the spatial resolution of the input when training the FNO model.Our findings can help optimize FNO for future fluid flow simulations. 展开更多
关键词 Fourier neural operator high-resolution simulation fluid flow vorticity equation
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Comparative analysis of different machine learning algorithms for urban footprint extraction in diverse urban contexts using high-resolution remote sensing imagery
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作者 GUI Baoling Anshuman BHARDWAJ Lydia SAM 《Journal of Geographical Sciences》 2025年第3期664-696,共33页
While algorithms have been created for land usage in urban settings,there have been few investigations into the extraction of urban footprint(UF).To address this research gap,the study employs several widely used imag... While algorithms have been created for land usage in urban settings,there have been few investigations into the extraction of urban footprint(UF).To address this research gap,the study employs several widely used image classification method classified into three categories to evaluate their segmentation capabilities for extracting UF across eight cities.The results indicate that pixel-based methods only excel in clear urban environments,and their overall accuracy is not consistently high.RF and SVM perform well but lack stability in object-based UF extraction,influenced by feature selection and classifier performance.Deep learning enhances feature extraction but requires powerful computing and faces challenges with complex urban layouts.SAM excels in medium-sized urban areas but falters in intricate layouts.Integrating traditional and deep learning methods optimizes UF extraction,balancing accuracy and processing efficiency.Future research should focus on adapting algorithms for diverse urban landscapes to enhance UF extraction accuracy and applicability. 展开更多
关键词 urban footprint mapping high-resolution remote sensing imagery machine learning deep learning segmentanythingmodel
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High-resolution Standardized Precipitation Evapotranspiration Index(SPEI)reveals trends in drought and vegetation water availability in China
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作者 Qian He Ming Wang +1 位作者 Kai Liu Bowen Wang 《Geography and Sustainability》 2025年第2期117-130,共14页
Understanding vegetation water availability can be important for managing vegetation and combating climate change.Changes in vegetation water availability throughout China remains poorly understood,especially at a hig... Understanding vegetation water availability can be important for managing vegetation and combating climate change.Changes in vegetation water availability throughout China remains poorly understood,especially at a high spatial resolution.Standardized Precipitation Evapotranspiration Index(SPEI)is an ideal water availability index for assessing the spatiotemporal characteristics of drought and investigating the vegetation-water availability relationship.However,no high-resolution and long-term SPEI datasets over China are available.To fill this gap,we developed a new model based on machine learning to obtain high-resolution(1 km)SPEI data by combining climate variables with topographical and geographical features.Here,we analyzed the long-term drought over the past century(1901–2020)and vegetation-water availability relationship in the past two decades(2000–2020).The century-long drought trend analyses indicated an overall drying trend across China with increasing drought frequency,duration,and severity during the past century.We found that drought events in 1901–1961 showed a larger increase than that in 1961–2020,with the Qinghai-Xizang Plateau showing a significant drying trend during 1901–1960 but a wetting trend during 1961–2020.There were 13.90%and 28.21%of vegetation in China showing water deficit and water surplus respectively during 2000–2020.The water deficit area significantly shrank from 2000 to 2020 across China,which is dominated by the significant decrease in water deficit areas in South China.Among temperature,precipitation,and vegetation abundance,temperature is the most important factor for the vegetation-water availability dynamics in China over the past two decades,with high temperature contributing to water deficit.Our findings are important for water and vegetation management under a warming climate. 展开更多
关键词 Standardized Precipitation Evapotranspiration Index(SPEI) Long-term drought Vegetation-water relationship high-resolution dataset
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Precision Comparison and Analysis of Multi-stereo Fusion and Multi-view Matching Based on High-Resolution Satellite Data
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作者 LIU Tengfei HUANG Xu HUANG Zefeng 《Transactions of Nanjing University of Aeronautics and Astronautics》 2025年第5期577-588,共12页
High-resolution sub-meter satellite data play an increasingly crucial role in the 3D real-scene China construction initiative.Current research on 3D reconstruction using high-resolution satellite data primarily focuse... High-resolution sub-meter satellite data play an increasingly crucial role in the 3D real-scene China construction initiative.Current research on 3D reconstruction using high-resolution satellite data primarily focuses on two approaches:Multi-stereo fusion and multi-view matching.While algorithms based on these two methodologies for multi-view image 3D reconstruction have reached relative maturity,no systematic comparison has been conducted specifically on satellite data to evaluate the relative merits of multi-stereo fusion versus multi-view matching methods.This paper conducts a comparative analysis of the practical accuracy of both approaches using high-resolution satellite datasets from diverse geographical regions.To ensure fairness in accuracy comparison,both methodologies employ non-local dense matching for cost optimization.Results demonstrate that the multi-stereo fusion method outperforms multi-view matching in all evaluation metrics,exhibiting approximately 1.2%higher average matching accuracy and 10.7%superior elevation precision in the experimental datasets.Therefore,for 3D modeling applications using satellite data,we recommend adopting the multi-stereo fusion approach for digital surface model(DSM)product generation. 展开更多
关键词 multi-stereo fusion reconstruction multi-view matching reconstruction non-local dense matching method occlusion detection high-resolution satellite data
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Multi-scale intelligent fusion and dynamic validation for high-resolution seismic data processing in drilling
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作者 YUAN Sanyi XU Yanwu +2 位作者 XIE Renjun CHEN Shuai YUAN Junliang 《Petroleum Exploration and Development》 2025年第3期680-691,共12页
During drilling operations,the low resolution of seismic data often limits the accurate characterization of small-scale geological bodies near the borehole and ahead of the drill bit.This study investigates high-resol... During drilling operations,the low resolution of seismic data often limits the accurate characterization of small-scale geological bodies near the borehole and ahead of the drill bit.This study investigates high-resolution seismic data processing technologies and methods tailored for drilling scenarios.The high-resolution processing of seismic data is divided into three stages:pre-drilling processing,post-drilling correction,and while-drilling updating.By integrating seismic data from different stages,spatial ranges,and frequencies,together with information from drilled wells and while-drilling data,and applying artificial intelligence modeling techniques,a progressive high-resolution processing technology of seismic data based on multi-source information fusion is developed,which performs simple and efficient seismic information updates during drilling.Case studies show that,with the gradual integration of multi-source information,the resolution and accuracy of seismic data are significantly improved,and thin-bed weak reflections are more clearly imaged.The updated seismic information while-drilling demonstrates high value in predicting geological bodies ahead of the drill bit.Validation using logging,mud logging,and drilling engineering data ensures the fidelity of the processing results of high-resolution seismic data.This provides clearer and more accurate stratigraphic information for drilling operations,enhancing both drilling safety and efficiency. 展开更多
关键词 high-resolution seismic data processing while-drilling update while-drilling logging multi-source information fusion thin-bed weak reflection artificial intelligence modeling
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基于SPH-DEM耦合的鸟撞风挡玻璃数值仿真研究
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作者 刘宗兴 曹苗 +2 位作者 盛家铖 张春阳 刘军 《航空工程进展》 2026年第1期108-115,共8页
玻璃类脆性材料被广泛用于飞机风挡结构,其位于飞机前部迎风面,易遭受鸟体撞击而碎裂。脆性的风挡玻璃碎裂参数测试困难,一般采用弹塑性本构模型及失效应变描述玻璃的受力变形及破坏,采用传统的有限元法(FEM)难以仿真鸟撞后风挡玻璃的... 玻璃类脆性材料被广泛用于飞机风挡结构,其位于飞机前部迎风面,易遭受鸟体撞击而碎裂。脆性的风挡玻璃碎裂参数测试困难,一般采用弹塑性本构模型及失效应变描述玻璃的受力变形及破坏,采用传统的有限元法(FEM)难以仿真鸟撞后风挡玻璃的细碎裂纹的扩展。基于碎裂问题数值计算的离散元法(DEM),通过试验数据标定有机玻璃碎裂的DEM微观参数,建立基于光滑粒子流体力学(SPH)-DEM耦合分析方法的鸟撞平板风挡玻璃数值仿真模型。结果表明:鸟体撞击作用下风挡玻璃的碎裂过程计算结果与鸟撞试验测试结果一致性良好,SPH-DEM耦合分析方法可以更加精确模拟鸟撞作用下风挡玻璃的碎裂,为鸟撞飞机风挡玻璃数值仿真提供了新的研究方法和思路。 展开更多
关键词 SPH-dem耦合分析 鸟撞 数值仿真 风挡玻璃 碎裂
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基于CFD-DEM耦合的碾米颗粒运动模拟与方法研究
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作者 杨勇 周龙 +2 位作者 范吉军 余南辉 李园 《食品与机械》 北大核心 2026年第1期64-71,共8页
[目的]针对卧式碾米机在碾米过程中造成颗粒破碎和过碾的问题,提出通过改变吸风气流方向提高糙米颗粒的碾磨质量。[方法]采用CFD-DEM耦合方法,分别对上吸风10 m/s、下吸风5 m/s和无风速3种状态进行数值仿真分析,并通过物理样机碾磨试验... [目的]针对卧式碾米机在碾米过程中造成颗粒破碎和过碾的问题,提出通过改变吸风气流方向提高糙米颗粒的碾磨质量。[方法]采用CFD-DEM耦合方法,分别对上吸风10 m/s、下吸风5 m/s和无风速3种状态进行数值仿真分析,并通过物理样机碾磨试验验证仿真结果。[结果]随着气流方向由上吸风转变到下吸风,颗粒沿Y轴的上升速度vy及三轴合成平均速度v整体降低,同层段位置处上吸风颗粒速度vy大于下吸风的,在碾白室中下部处明显观察到上吸风颗粒平均速度v大于下吸风颗粒的,碾磨区域内颗粒运动能力的差异导致容易过碾和破损区域的受力情况明显不同,颗粒运动能力强时碾白室底部颗粒受到的挤压力减小,颗粒运动能力弱时碾白室底部颗粒受到的挤压力增大;颗粒翻滚角速度在上吸风的作用下,对比无风速和下吸风效果增强;每种状态下3次的物理试验结果,上吸风10 m/s、无风速和下吸风5 m/s的碾磨度平均值分别为1.90%,2.20%,2.78%,破损率平均值分别为0.37%,0.46%,0.60%。[结论]上吸风状态下颗粒碾磨过程中的流动和受力特性优于无风速和下吸风的情况;上吸风比无风速和下吸风的碾磨度和破碎率明显下降。 展开更多
关键词 碾米颗粒 CFD-dem 颗粒流动 多孔介质模型
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DEM分辨率对土壤流失模型影响研究
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作者 吴洋 《水利科技与经济》 2026年第1期105-109,共5页
本文采用RUSLE模型对研究区域的水土流失进行了定量评估,探讨了不同分辨率DEM数据对土壤侵蚀模拟结果的影响。模型综合考虑降雨侵蚀力(R)、土壤可蚀性(K)、地形因子(LS)、植被覆盖(C)及水土保持措施(P)五大因子,通过ArcGIS平台进行空间... 本文采用RUSLE模型对研究区域的水土流失进行了定量评估,探讨了不同分辨率DEM数据对土壤侵蚀模拟结果的影响。模型综合考虑降雨侵蚀力(R)、土壤可蚀性(K)、地形因子(LS)、植被覆盖(C)及水土保持措施(P)五大因子,通过ArcGIS平台进行空间分析。研究中分别基于30 m与90 m分辨率的DEM进行模拟,并结合20 a降水数据、土壤质地资料与土地利用类型构建因子图。结果表明,DEM分辨率显著影响土壤侵蚀模拟的空间精度,高分辨率(30 m)模型揭示出更为细致的侵蚀风险分布,评估的土壤流失率高达282774 t/(hm^(2)·a);而低分辨率(90 m)模型结果则低估了侵蚀风险,最大值仅为13.79 t/(hm^(2)·a)。本研究强调了地形数据精度在水土保持规划中的关键作用,为区域生态保护与土地资源管理提供了科学依据。 展开更多
关键词 dem 水土流失 LS因子 分辨率 R因子 K因子
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基于CFD-DEM方法的高炉炉料轨迹落点预测
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作者 何潺 刘丕亮 +1 位作者 林帅辉 吴博 《冶金能源》 北大核心 2026年第1期62-69,共8页
针对当前高炉炉料落点预测的不足,文章采用CFD-DEM方法分析高炉炉料轨迹和落点位置,并利用程树森等提出的数学模型验证CFD-DEM模型的准确性。该方法全面考虑多种影响因素,包括科里奥利力、煤气流量、溜槽的旋转速度和倾角等,直观和精准... 针对当前高炉炉料落点预测的不足,文章采用CFD-DEM方法分析高炉炉料轨迹和落点位置,并利用程树森等提出的数学模型验证CFD-DEM模型的准确性。该方法全面考虑多种影响因素,包括科里奥利力、煤气流量、溜槽的旋转速度和倾角等,直观和精准地再现炉料在高炉内的运动过程。结果表明:当溜槽转速为1.05 rad/s时,科里奥利力对焦炭和矿石落点的影响分别达到28%和22%,煤气流非均匀性使焦炭和矿石的落点半径外移2.74%和3.87%。精准预测料流轨迹落点必须综合考虑科里奥利力和煤气流的影响。与数学模型对比,CFD-DEM模型对焦炭和矿石落点半径预测均方根误差分别为0.060 m和0.055 m,最大相对偏差不超过5%,与数学模型预测结果几乎一致,因此能够准确预测高炉炉料轨迹落点,为后续高炉布料操作提供新的理论依据。 展开更多
关键词 无料钟炉顶高炉 CFD-dem 数学模型验证 科里奥利力 气固耦合
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OPTIMIZATION OF WEIGHTED HIGH-RESOLUTION RANGE PROFILE FOR RADAR TARGET RECOGNITION 被引量:1
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作者 朱劼昊 周建江 吴杰 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2011年第2期157-162,共6页
For the recognition of high-resolution range profile (HRRP) in radar, the weighted HRRP can reduce the instability of range cells caused by the attitude change of targets. A novel approach is proposed to optimize th... For the recognition of high-resolution range profile (HRRP) in radar, the weighted HRRP can reduce the instability of range cells caused by the attitude change of targets. A novel approach is proposed to optimize the weighted HRRP. In the approach, the separability of weighted HRRPs in different targets is measured by de- signing an objective function, and the weighted coefficients are computed by using the gradient descent method, thus enhancing the influence of stable range cells. Simulation results based on five aircraft models show that the approach can effectively optimize the weighted HRRP and improve the recognition accuracy. 展开更多
关键词 radar target recognition high-resolution range profile scattering center model gradient descentmethod
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国产航天宏图一号SAR卫星数据干涉测量重建DEM精度验证与分析 被引量:1
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作者 张双成 王铭辉 +4 位作者 杨娜 路聚峰 王杰 何晓宁 禹文强 《遥感学报》 北大核心 2025年第5期1290-1304,共15页
2023年3月30日,由国内商业航天企业航天宏图信息技术股份有限公司(以下简称航天宏图)运营的航天宏图一号卫星(PIESAT-1)成功发射,为国产SAR卫星的发展注入了新的动力,作为“女娲星座”首发星,其具备高精度地形测绘、高分宽幅成像、高精... 2023年3月30日,由国内商业航天企业航天宏图信息技术股份有限公司(以下简称航天宏图)运营的航天宏图一号卫星(PIESAT-1)成功发射,为国产SAR卫星的发展注入了新的动力,作为“女娲星座”首发星,其具备高精度地形测绘、高分宽幅成像、高精度形变监测等能力。但目前关于该卫星的相关研究较少,亟须探索其真实的测图能力。本文利用星载In SAR生产DEM技术流程,针对PIESAT-1独特的“1主+3辅”车轮编队构型进行相应技术调整。首先,选取了山地、丘陵、平原3种特殊的地形为研究对象,结合PIESAT-1卫星在轨测试期间获取的单视斜距复影像干涉对(L1B)数据,利用In SAR技术提取DEM,并以ICESat-2控制点和Copernicus DEM作为参考,验证PIESAT-1的地形测绘精度。结果表明,在山地、丘陵和平原3种地形条件下,PIESAT-1 DEM产品的垂直精度均高于Copernicus DEM,RMSE值分别为4.8727 m、7.8329 m、0.9857 m;同时,PIESAT-1 DEM产品在空间分辨率上优于Copernicus DEM产品,能够更清晰地描绘地形的细节特征;本文还考虑了植被对DEM产品精度的影响,在高植被区域,植被所产生的误差不可无视。通过本文实验表明PIESAT-1用于全球地形测绘任务时,独特的编队方式使其在空间分辨率、测绘效率、测量精度上均占据巨大优势,这为“女娲星座”的业务化应用提供了重要参考。 展开更多
关键词 航天宏图一号 星载InSAR地形测绘 ICESat-2控制点 多基线相位解缠 dem精度验证 植被影响
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基于CFD-DEM的斜面平台对下降管内混合颗粒流动的影响 被引量:1
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作者 孙雪峰 张德俐 +5 位作者 刘浩 高豪磊 马瑞 王芳 金德禄 易维明 《农业工程学报》 北大核心 2025年第5期240-249,共10页
为改善生物质热解过程中混合颗粒在下降管热解反应器内部流动时生物质颗粒扰动较小、混合不充分的问题,该研究探讨了管内斜面平台对陶瓷球和生物质颗粒流动的影响。以斜面平台的位置、倾斜角度和高度为试验因素,以生物质颗粒管内离散度... 为改善生物质热解过程中混合颗粒在下降管热解反应器内部流动时生物质颗粒扰动较小、混合不充分的问题,该研究探讨了管内斜面平台对陶瓷球和生物质颗粒流动的影响。以斜面平台的位置、倾斜角度和高度为试验因素,以生物质颗粒管内离散度为评判标准,通过计算流体力学与离散元法(computational fluid dynamics-discrete element method,CFD-DEM)耦合仿真对混合颗粒流动过程进行模拟,并利用粒子图像测速技术进行了验证。结果表明,斜面平台高度对生物质颗粒离散度影响最大,其次为位置和角度,最佳工作参数为斜面平台底部距下降管拐角处245 mm,高度为27 mm,角度为149°,相较于无斜面平台工况,生物质颗粒离散度提高了50.24%,进而提升了混合颗粒的混合程度。斜面平台的引入使得下降管内生物质颗粒和陶瓷球的轴向平均速度分别降低了14.38%和11.43%,平均停留时间分别升高了20.00%和5.75%,改变了无斜面平台时混合颗粒的向心流动特性,表现为抛物线形流动特性,打破了上疏下密的分布状态,使混合颗粒偏析降低,混合更为均匀。该研究结果能够为下降管式生物质热解反应器的设计与优化提供一定支持,有利于生物质快速热解技术的发展。 展开更多
关键词 生物质 下降管 计算机仿真 CFD-dem 气固两相流
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基于SPH-DEM并行计算的滑坡涌浪模拟
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作者 唐岳灏 姜清辉 《人民长江》 北大核心 2025年第5期136-142,共7页
为解决滑坡体与水体的强耦合及非线性水波演化形成的复杂流-固耦合问题,采用光滑粒子流方法(SPH)模拟水体动力学特性,通过离散元方法(DEM)模拟滑坡体大变形与不连续问题,构建了SPH-DEM流-固耦合算法,并开发了基于分布式MPI的并行计算程... 为解决滑坡体与水体的强耦合及非线性水波演化形成的复杂流-固耦合问题,采用光滑粒子流方法(SPH)模拟水体动力学特性,通过离散元方法(DEM)模拟滑坡体大变形与不连续问题,构建了SPH-DEM流-固耦合算法,并开发了基于分布式MPI的并行计算程序,实现了SPH-DEM耦合过程的大规模高性能计算。将该程序应用于湖北省江坪河水库白日垭崩塌体滑坡模拟,再现了滑坡发展、涌浪形成、河道传播、冲击大坝的灾害链过程。结果显示:涌浪在坝前最大壅高474.00 m,低于坝高476.00 m,此程序在进程数量128时取得了超过70%的并行加速效率。研究成果能有效分析滑坡涌浪灾害动力学过程,开发的并行程序可为其他国产同类软件提供借鉴。 展开更多
关键词 滑坡涌浪 流-固耦合 离散元(dem) 光滑粒子流(SPH) 白日垭崩塌体 江坪河水库
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