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Motion In-Betweening via Frequency-Domain Diffusion Model
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作者 Qiang Zhang Shuo Feng +2 位作者 Shanxiong Chen Teng Wan Ying Qi 《Computers, Materials & Continua》 2026年第1期275-296,共22页
Human motion modeling is a core technology in computer animation,game development,and humancomputer interaction.In particular,generating natural and coherent in-between motion using only the initial and terminal frame... Human motion modeling is a core technology in computer animation,game development,and humancomputer interaction.In particular,generating natural and coherent in-between motion using only the initial and terminal frames remains a fundamental yet unresolved challenge.Existing methods typically rely on dense keyframe inputs or complex prior structures,making it difficult to balance motion quality and plausibility under conditions such as sparse constraints,long-term dependencies,and diverse motion styles.To address this,we propose a motion generation framework based on a frequency-domain diffusion model,which aims to better model complex motion distributions and enhance generation stability under sparse conditions.Our method maps motion sequences to the frequency domain via the Discrete Cosine Transform(DCT),enabling more effective modeling of low-frequency motion structures while suppressing high-frequency noise.A denoising network based on self-attention is introduced to capture long-range temporal dependencies and improve global structural awareness.Additionally,a multi-objective loss function is employed to jointly optimize motion smoothness,pose diversity,and anatomical consistency,enhancing the realism and physical plausibility of the generated sequences.Comparative experiments on the Human3.6M and LaFAN1 datasets demonstrate that our method outperforms state-of-the-art approaches across multiple performance metrics,showing stronger capabilities in generating intermediate motion frames.This research offers a new perspective and methodology for human motion generation and holds promise for applications in character animation,game development,and virtual interaction. 展开更多
关键词 Motion generation diffusion model frequency domain human motion synthesis self-attention network 3D motion interpolation
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Visual prognosis and survival outcomes in patients with ocular adnexal diffuse large B-cell lymphoma
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作者 Sirawit Wainipitapong Orapan Aryasit +1 位作者 Panarat Noiperm Mansing Ratanasukon 《International Journal of Ophthalmology(English edition)》 2026年第2期354-361,共8页
AIM:To investigate the clinical characteristics and treatment outcomes,including visual function and overall survival(OS)of patients with ocular adnexal diffuse large B-cell lymphoma(OA-DLBCL).METHODS:This retrospecti... AIM:To investigate the clinical characteristics and treatment outcomes,including visual function and overall survival(OS)of patients with ocular adnexal diffuse large B-cell lymphoma(OA-DLBCL).METHODS:This retrospective cohort study enrolled 29 patients diagnosed with OA-DLBCL based on histopathological biopsy between 2006 and 2023.Patients were stratified into two subgroups:primary OA-DLBCL(no prior history of lymphoma)and secondary OA-DLBCL(history of DLBCL at non-ocular adnexal sites).OS was defined as the time interval from OA-DLBCL diagnosis to death from any cause.Survival analysis was performed using the Kaplan–Meier method,and prognostic factors affecting OS were identified using multivariate Cox proportional hazards regression with a stepwise selection approach.RESULTS:The cohort included 24 patients with primary OA-DLBCL(13 males,11 females;mean age:61.36±18.29y)and 5 patients with secondary OA-DLBCL(2 males,3 females;mean age:50.94±18.17y).Among the primary OA-DLBCL subgroup,12 patients(50%)presented with advanced disease(Ann Arbor stage IIIE–IV),and 16 patients(66%)were classified as T4 disease according to the tumor-node-metastasis(TNM)staging system.The mean final visual acuity was 1.72±1.10 in the primary group and 0.90±1.18 in the secondary group.The 5-year OS rate for the entire cohort was 27.7%.Multivariate analysis identified five factors significantly associated with poor survival outcomes:epiphora[adjusted hazard ratio(aHR),36.95],atherosclerotic cardiovascular disease(aHR,10.08),human immunodeficiency virus(HIV)infection(aHR,12.47),M1 stage(aHR,6.99),and secondary OA-DLBCL(aHR,6.03;all P<0.05).The median OS was 1.68y for primary OA-DLBCL and 1.12y for secondary OA-DLBCL.CONCLUSION:A substantial proportion of patients with primary OA-DLBCL present with advanced-stage disease at diagnosis.Epiphora,atherosclerotic cardiovascular disease,HIV infection,M1 stage,and secondary OA-DLBCL are independent prognostic factors for poor survival outcomes.These findings emphasize the urgent need for optimized therapeutic strategies and early screening protocols to improve the management of OA-DLBCL,particularly in developing countries. 展开更多
关键词 ocular adnexal diffuse large B-cell lymphoma visual prognosis overall survival prognostic factors Ann Arbor staging tumor-node-metastasis staging
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H–He Demixing Driven by Anisotropic Hydrogen Diffusion 被引量:1
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作者 Xiaoju Chang Dongdong Kang +1 位作者 Bo Chen Jiayu Dai 《Chinese Physics Letters》 2025年第5期33-42,共10页
The dynamics of phase separation in H–He binary systems within gas giants such as Jupiter and Saturn exhibit remarkable complexity, yet lack systematic investigation. Through large-scale machine-learning-accelerated ... The dynamics of phase separation in H–He binary systems within gas giants such as Jupiter and Saturn exhibit remarkable complexity, yet lack systematic investigation. Through large-scale machine-learning-accelerated molecular dynamics simulations spanning broad temperature-pressure-composition(2000–10000 K, 1–7 Mbar,pure H to pure He) regimes, we systematically determine self and mutual diffusion coefficients in H–He systems and establish a six-dimensional framework correlating temperature, pressure, helium abundance, phase separation degree, diffusion coefficients, and anisotropy. Key findings reveal that hydrogen exhibits active directional migration with pronounced diffusion anisotropy, whereas helium passively aggregates in response. While the conventional mixing rule underestimates mutual diffusion coefficients by neglecting velocity cross-correlations,the assumption of an ideal thermodynamic factor(Q = 1) overestimates them due to unaccounted non-ideal thermodynamic effects—both particularly pronounced in strongly phase-separated regimes. Notably, hydrogen's dual role, anisotropic diffusion and bond stabilization via helium doping, modulates demixing kinetics. Large-scale simulations(216,000 atoms) propose novel phase-separation paradigms, such as “hydrogen bubble/wisp” formation, challenging the classical “helium rain” scenario, striving to bridge atomic-scale dynamics to planetary-scale phase evolution. 展开更多
关键词 molecular dynamics simulations gas giants helium diffusion h he systems hydrogen diffusion determine self mutual diffusion coefficients h he binary systems dynamics phase separation
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Influence of Al,Cu and Mn additions on diffusion behaviors in CoCrFeNi high-entropy alloys 被引量:1
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作者 Juan CHEN Zhen-zhong ZHANG +1 位作者 Jin-kun XIAO Li-jun ZHANG 《Transactions of Nonferrous Metals Society of China》 2025年第1期184-193,共10页
The interdiffusion coefficients in Al_(0.2)CoCrFeNi,CoCrCu_(0.2)FeNi,and CoCrFeMn_(0.2)Ni high-entropy alloys were efficiently determined by combining diffusion couple experiments and high-throughput determination of ... The interdiffusion coefficients in Al_(0.2)CoCrFeNi,CoCrCu_(0.2)FeNi,and CoCrFeMn_(0.2)Ni high-entropy alloys were efficiently determined by combining diffusion couple experiments and high-throughput determination of interdiffusion coefficients(HitDIC)software at 1273−1373 K.The results show that the addition of Al,Cu,and Mn to CoCrFeNi high-entropy alloys promotes the diffusion of Co,Cr,and Fe atoms.The comparison of tracer diffusion coefficients indicates that there is no sluggish diffusion in tracer diffusion on the thermodynamic temperature scale for the present Al_(0.2)CoCrFeNi,CoCrCu_(0.2)FeNi,and CoCrFeMn_(0.2)Ni high-entropy alloys.The linear relationship between diffusion entropy and activation energy reveals that the diffusion process of atoms is unaffected by an increase in the number of components as long as the crystal structure remains unchanged. 展开更多
关键词 Co−Cr−Fe−Ni high-entropy alloy diffusION interdiffusivity diffusion couple
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AI绘图助力三维设计发展——以Stable Diffusion为例 被引量:2
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作者 刘凇麟 杨蕾颖 《昆明冶金高等专科学校学报》 2025年第1期61-69,共9页
AI绘图工具是利用人工智能技术,通过本地部署训练辅助或完全自动生成绘画作品的软件工具。目前常用的AI绘图工具有DALL-E 2、Midjourney、Stable Diffusion等,其中以Stable Diffusion使用最为广泛。通过不断更新图像的噪声分布,软件在... AI绘图工具是利用人工智能技术,通过本地部署训练辅助或完全自动生成绘画作品的软件工具。目前常用的AI绘图工具有DALL-E 2、Midjourney、Stable Diffusion等,其中以Stable Diffusion使用最为广泛。通过不断更新图像的噪声分布,软件在本地计算机上生成高质量图像。以实际设计项目为例,应用Stable Diffusion在三维设计中帮助设计师快速生成草图和效果图,得到多种设计风格和创作方式,大大提高了设计的效率和乐趣,实践证明AI绘图工具在环境艺术设计、建筑设计等多个领域具有巨大的应用潜力。 展开更多
关键词 AI绘图 Stable diffusion 三维设计
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Elevated temperature magnetic microstructures and demagnetization mechanism for grain boundary diffused dual-main-phase(Nd,Ce)-Fe-B magnets 被引量:2
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作者 Yifei Xiao Lele Zhang +7 位作者 Wei Yang Tao Liu Qisong Sun Xiaolong Song Yikun Fang Anhua Li Minggang Zhu Wei Li 《Journal of Materials Science & Technology》 2025年第4期10-23,共14页
The combination of dual-main-phase(DMP)(Nd,Ce)-Fe-B magnets and grain boundary diffusion process(GBDP)is currently a research topic for obtaining high-cost performance materials in rare earth permanent magnet fields.T... The combination of dual-main-phase(DMP)(Nd,Ce)-Fe-B magnets and grain boundary diffusion process(GBDP)is currently a research topic for obtaining high-cost performance materials in rare earth permanent magnet fields.The novel structural features of GBDP(Nd,Ce)-Fe-B magnets give a version of different domain reversal processes from those of non-diffused magnets.In this work,the in-situ magnetic domain evolution of the DMP magnets was observed at elevated temperatures,and the temperature demagnetization and coercivity mechanism of the GBDP dual-main-phase(Nd,Ce)-Fe-B magnets are discussed.The results show that the shell composition of different types of grains in DMP magnets is similar,while the magnetic microstructure results indicate the Ce-rich grains tend to demagnetize first.Dy-rich shell with a high anisotropic field caused by GBDP leads to an increase in the nucleation field,which enhances the coercivity.It is found that much more grains exhibit single domain characteristics in the remanent state for GBDP dual-main-phase(Nd,Ce)-Fe-B magnets.In addition,the grains that undergo demagnetization first are Ce-rich or Nd-rich grains,which is different from that of non-diffused magnets.These results were not found in previous studies but can be intuitively characterized from the perspective of magnetic domains in this work,providing a new perspective and understanding of the performance improvement of magnetic materials. 展开更多
关键词 Magnetic microstructures Dual-main-phase (Nd Ce)-Fe-B diffused Dy Rare earth permanent magnet materials Grain boundary diffusion process(GBDP)
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Prediction of radionuclide diffusion enabled by missing data imputation and ensemble machine learning 被引量:1
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作者 Jun-Lei Tian Jia-Xing Feng +4 位作者 Jia-Cong Shen Lei Yao Jing-Yan Wang Tao Wu Yao-Lin Zhao 《Nuclear Science and Techniques》 2025年第10期47-61,共15页
Missing values in radionuclide diffusion datasets can undermine the predictive accuracy and robustness of the machine learning(ML)models.In this study,regression-based missing data imputation method using a light grad... Missing values in radionuclide diffusion datasets can undermine the predictive accuracy and robustness of the machine learning(ML)models.In this study,regression-based missing data imputation method using a light gradient boosting machine(LGBM)algorithm was employed to impute more than 60%of the missing data,establishing a radionuclide diffusion dataset containing 16 input features and 813 instances.The effective diffusion coefficient(D_(e))was predicted using ten ML models.The predictive accuracy of the ensemble meta-models,namely LGBM-extreme gradient boosting(XGB)and LGBM-categorical boosting(CatB),surpassed that of the other ML models,with R^(2)values of 0.94.The models were applied to predict the D_(e)values of EuEDTA^(−)and HCrO_(4)^(−)in saturated compacted bentonites at compactions ranging from 1200 to 1800 kg/m^(3),which were measured using a through-diffusion method.The generalization ability of the LGBM-XGB model surpassed that of LGB-CatB in predicting the D_(e)of HCrO_(4)^(−).Shapley additive explanations identified total porosity as the most significant influencing factor.Additionally,the partial dependence plot analysis technique yielded clearer results in the univariate correlation analysis.This study provides a regression imputation technique to refine radionuclide diffusion datasets,offering deeper insights into analyzing the diffusion mechanism of radionuclides and supporting the safety assessment of the geological disposal of high-level radioactive waste. 展开更多
关键词 Machine learning Radionuclide diffusion BENTONITE Regression imputation Missing data diffusion experiments
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Medical Image Encryption Based on Fisher-Yates Scrambling and Filter Diffusion 被引量:1
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作者 HUANG Jiacin GUO Yali +1 位作者 GAO Ruoyun LI Shanshan 《Journal of Shanghai Jiaotong university(Science)》 2025年第1期136-152,共17页
A medical image encryption is proposed based on the Fisher-Yates scrambling,filter diffusion and S-box substitution.First,chaotic sequence associated with the plaintext is generated by logistic-sine-cosine system,whic... A medical image encryption is proposed based on the Fisher-Yates scrambling,filter diffusion and S-box substitution.First,chaotic sequence associated with the plaintext is generated by logistic-sine-cosine system,which is used for the scrambling,substitution and diffusion processes.The three-dimensional Fisher-Yates scrambling,S-box substitution and diffusion are employed for the first round of encryption.The chaotic sequence is adopted for secondary encryption to scramble the ciphertext obtained in the first round.Then,three-dimensional filter is applied to diffusion for further useful information hiding.The key to the algorithm is generated by the combination of hash value of plaintext image and the input parameters.It improves resisting ability of plaintext attacks.The security analysis shows that the algorithm is effective and efficient.It can resist common attacks.In addition,the good diffusion effect shows that the scheme can solve the differential attacks encountered in the transmission of medical images and has positive implications for future research. 展开更多
关键词 medical image encryption Fisher-Yates scrambling three-dimensional filter diffusion bidirectional diffusion S-box substitution
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Stable Diffusion在设计类专业教学中的应用——以三维设计软件应用课程为例
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作者 刘凇麟 杨蕾颖 +2 位作者 危威 李健僖 张馨 《昆明冶金高等专科学校学报》 2025年第4期119-124,共6页
随着人工智能技术的快速发展,Stable Diffusion作为一种先进的图像生成和扩散模型,在设计领域中显现出巨大的应用潜力。通过Stable Diffusion在三维设计软件应用课程中的具体应用案例,结合课程目标和内容,分析其在提升教学质量、激发学... 随着人工智能技术的快速发展,Stable Diffusion作为一种先进的图像生成和扩散模型,在设计领域中显现出巨大的应用潜力。通过Stable Diffusion在三维设计软件应用课程中的具体应用案例,结合课程目标和内容,分析其在提升教学质量、激发学生创意和拓展设计思维方面的作用,符合当今教育和技术发展的趋势。通过实际教学,证明AI融入教学,能够有效提高学生学习兴趣和参与度、增强设计作品多样性和创新性;同时,对传统设计类教学也提出了挑战。提出了新的教学内容和应用建议,为艺术设计教育的发展提供了新的思路和方法。 展开更多
关键词 Stablediffusion模型 设计类专业 教学
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Anime Generation through Diffusion and Language Models:A Comprehensive Survey of Techniques and Trends
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作者 Yujie Wu Xing Deng +4 位作者 Haijian Shao Ke Cheng Ming Zhang Yingtao Jiang Fei Wang 《Computer Modeling in Engineering & Sciences》 2025年第9期2709-2778,共70页
The application of generative artificial intelligence(AI)is bringing about notable changes in anime creation.This paper surveys recent advancements and applications of diffusion and language models in anime generation... The application of generative artificial intelligence(AI)is bringing about notable changes in anime creation.This paper surveys recent advancements and applications of diffusion and language models in anime generation,focusing on their demonstrated potential to enhance production efficiency through automation and personalization.Despite these benefits,it is crucial to acknowledge the substantial initial computational investments required for training and deploying these models.We conduct an in-depth survey of cutting-edge generative AI technologies,encompassing models such as Stable Diffusion and GPT,and appraise pivotal large-scale datasets alongside quantifiable evaluation metrics.Review of the surveyed literature indicates the achievement of considerable maturity in the capacity of AI models to synthesize high-quality,aesthetically compelling anime visual images from textual prompts,alongside discernible progress in the generation of coherent narratives.However,achieving perfect long-form consistency,mitigating artifacts like flickering in video sequences,and enabling fine-grained artistic control remain critical ongoing challenges.Building upon these advancements,research efforts have increasingly pivoted towards the synthesis of higher-dimensional content,such as video and three-dimensional assets,with recent studies demonstrating significant progress in this burgeoning field.Nevertheless,formidable challenges endure amidst these advancements.Foremost among these are the substantial computational exigencies requisite for training and deploying these sophisticated models,particularly pronounced in the realm of high-dimensional generation such as video synthesis.Additional persistent hurdles include maintaining spatial-temporal consistency across complex scenes and mitigating ethical considerations surrounding bias and the preservation of human creative autonomy.This research underscores the transformative potential and inherent complexities of AI-driven synergy within the creative industries.We posit that future research should be dedicated to the synergistic fusion of diffusion and autoregressive models,the integration of multimodal inputs,and the balanced consideration of ethical implications,particularly regarding bias and the preservation of human creative autonomy,thereby establishing a robust foundation for the advancement of anime creation and the broader landscape of AI-driven content generation. 展开更多
关键词 diffusion models language models anime generation image synthesis video generation stable diffusion AIGC
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Diffusion behavior along Nd-Fe-B grain boundaries in different directions and mechanism of coercivity strengthening
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作者 Shengwu Shen Munan Yang +7 位作者 Shuwei Zhong Hang Wang Sangen Luo Jiajie Li Xi Yu Sajjad Ur Rehman Ihor Bulyk Haijiao Xie 《Journal of Rare Earths》 2025年第4期766-773,I0005,共9页
In this study,DyF_(3)powder was sprayed onto the polar and side surfaces of the magnets to determine the anisotropic diffusion mechanism of Dy in the sintered Nd-Fe-B magnet.The coercivity and squareness of the magnet... In this study,DyF_(3)powder was sprayed onto the polar and side surfaces of the magnets to determine the anisotropic diffusion mechanism of Dy in the sintered Nd-Fe-B magnet.The coercivity and squareness of the magnet in which the diffusion of Dy is perpendicular to the c-axis(a-magnet)are lower than those of the magnet with the diffusion of Dy parallel to the c-axis(c-magnet).Compared with the c-magnet,the a-magnet has a longer Dy-enrichment region from the diffusion surface,where Dy is enriched in the 2:14:1 grain.By contrast,the Dy concentration in the grain boundaries beyond the Dy enrichment region is lower in the a-magnet.Moreover,the Dy shells beyond the Dy enrichment region in the a-magnet are distributed on the side surfaces of the 2:14:1 grains but not on the polar surfaces.Based on the micromagnetic simulation,the Dy shells on the polar surfaces of the grains are more effective in enhancing coercivity.According to first-principle calculations,Dy migrating through 001 into the Nd vacancy in the Nd_(2)Fe_(14)B crystal has a higher diffusion barrier,thus indicating that the lattice diffusion of Dy parallel to the c-axis is more difficult. 展开更多
关键词 ND-FE-B Grain boundary diffusion Anisotropic diffusion Micromagnetic simulation First-principle calculations Rare earths
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Dissecting and Mitigating Semantic Discrepancy in Stable Diffusion for Image-to-Image Translation
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作者 Yifan Yuan Guanqun Yang +4 位作者 James Z.Wang Hui Zhang Hongming Shan Fei-Yue Wang Junping Zhang 《IEEE/CAA Journal of Automatica Sinica》 2025年第4期705-718,共14页
Finding suitable initial noise that retains the original image’s information is crucial for image-to-image(I2I)translation using text-to-image(T2I)diffusion models.A common approach is to add random noise directly to... Finding suitable initial noise that retains the original image’s information is crucial for image-to-image(I2I)translation using text-to-image(T2I)diffusion models.A common approach is to add random noise directly to the original image,as in SDEdit.However,we have observed that this can result in“semantic discrepancy”issues,wherein T2I diffusion models misinterpret the semantic relationships and generate content not present in the original image.We identify that the noise introduced by SDEdit disrupts the semantic integrity of the image,leading to unintended associations between unrelated regions after U-Net upsampling.Building on the widely-used latent diffusion model,Stable Diffusion,we propose a training-free,plugand-play method to alleviate semantic discrepancy and enhance the fidelity of the translated image.By leveraging the deterministic nature of denoising diffusion implicit models(DDIMs)inversion,we correct the erroneous features and correlations from the original generative process with accurate ones from DDIM inversion.This approach alleviates semantic discrepancy and surpasses recent DDIM-inversion-based methods such as PnP with fewer priors,achieving a speedup of 11.2 times in experiments conducted on COCO,ImageNet,and ImageNet-R datasets across multiple I2I translation tasks. 展开更多
关键词 DDIM inversion diffusion model image-to-image translation semantic discrepancy stable diffusion
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BEDiff:denoising diffusion probabilistic models for building extraction
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作者 LEI Yanjing WANG Yuan +3 位作者 CHAN Sixian HU Jie ZHOU Xiaolong ZHANG Hongkai 《Optoelectronics Letters》 2025年第5期298-305,共8页
Accurately identifying building distribution from remote sensing images with complex background information is challenging.The emergence of diffusion models has prompted the innovative idea of employing the reverse de... Accurately identifying building distribution from remote sensing images with complex background information is challenging.The emergence of diffusion models has prompted the innovative idea of employing the reverse denoising process to distill building distribution from these complex backgrounds.Building on this concept,we propose a novel framework,building extraction diffusion model(BEDiff),which meticulously refines the extraction of building footprints from remote sensing images in a stepwise fashion.Our approach begins with the design of booster guidance,a mechanism that extracts structural and semantic features from remote sensing images to serve as priors,thereby providing targeted guidance for the diffusion process.Additionally,we introduce a cross-feature fusion module(CFM)that bridges the semantic gap between different types of features,facilitating the integration of the attributes extracted by booster guidance into the diffusion process more effectively.Our proposed BEDiff marks the first application of diffusion models to the task of building extraction.Empirical evidence from extensive experiments on the Beijing building dataset demonstrates the superior performance of BEDiff,affirming its effectiveness and potential for enhancing the accuracy of building extraction in complex urban landscapes. 展开更多
关键词 booster guidance building extraction reverse denoising process diffusion model bediff which remote sensing images complex background diffusion models
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Magnetic resonance tractography of the cervical spine:A rapid diffusion tensor imaging protocol to serve as a clinical evaluation tool
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作者 Emilio P Supsupin Alejandro Serrano +7 位作者 Christopher Louviere Luke Pearson Mauricio Hernandez Vashisht Sekar Aboubakr Amer Ulas Cikla Mayur Virarkar Kazim Z Gumus 《World Journal of Radiology》 2025年第9期92-104,共13页
BACKGROUND Spinal cord injury can lead to long-term disability,but current imaging methods are limited in predicting outcomes.Rapid diffusion tensor imaging(DTI)has shown promise,yet its clinical utility remains under... BACKGROUND Spinal cord injury can lead to long-term disability,but current imaging methods are limited in predicting outcomes.Rapid diffusion tensor imaging(DTI)has shown promise,yet its clinical utility remains underexplored.AIM To evaluate the potential applications of a short DTI sequence,incorporated into a cervical spine magnetic resonance imaging(MRI)protocol,for characterizing a range of symptomatic spinal cord pathologies.We propose that cervical spine tractography can provide essential diagnostic information beyond what is currently available from conventional MRI.METHODS We utilized a quick DTI sequence to create tractography models of the cervical spinal cord in four patients with distinct pathologies of various etiologies:Cord contusion,metastasis,myelopathy,and multiple sclerosis.We used DSI Studio software for post-processing of tractography cases.Fiber tract findings for each pathology case were compared to five control cases from the same scanner by looking for individual differences in white matter tract integrity based on the fractional anisotropy(FA)and mean diffusivity(MD)of the regions of interest from controls.These correlated with clinical presentations and conventional MRI findings.RESULTS Control cases showed consistent and intact tract patterns with stable FA and MD values.In pathological cases,abnormalities in fiber orientation and tract continuity correlated with clinical symptoms and lesion locations.CONCLUSION The tractography models can provide additional information on white matter disruption that was not discernible on standard MRI sequences.However,its clinical use remains limited due to the need for specialized imaging protocols and complex post-processing,restricting its use to mostly academic settings. 展开更多
关键词 Cervical spinal cord diffusion tensor imaging TRACTOGRAPHY Fractional anisotropy Mean diffusivity
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Unexpected Young’s modulus dependence of refractory solute diffusion in NiCoFeCr-based high entropy alloys
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作者 Haoyang Yu Wei Fang +6 位作者 Tiexu Peng Chang Liu Hongxian Xie Bin Gan Xin Zhang Jia Li Fuxing Yin 《Journal of Materials Science & Technology》 2025年第27期270-281,共12页
Diffusion of solutes significantly affects the coarsening rate of γ'precipitates in precipitation-hardened high entropy alloys(PH-HEAs).In this work,we systematically study the refractory solutes M(Hf,Nb,Ta,Mo,W,... Diffusion of solutes significantly affects the coarsening rate of γ'precipitates in precipitation-hardened high entropy alloys(PH-HEAs).In this work,we systematically study the refractory solutes M(Hf,Nb,Ta,Mo,W,Re,Ru)diffusion in face-centered-cubic(FCC)NiCoFeCr lattice through a combination of first-principles calculations,diffusion couples,and coarsening of γ'precipitates experiments.Our calculations reveal that there exists a stronger negative correlation between solute diffusivity and Young’s modulus than between solute diffusivity and atomic size;i.e.,the higher the Young’s modulus,the more difficult solute diffusion is.Based on the electronic structure analysis,the underlying origins for such a relation-ship could be ascribed to the fact that solutes with high Young’s modulus have stronger bonds with neighboring host atoms,less compressibility,and thus poor diffusivity.Afterwards,the main interdiffu-sion coefficients of three refractory elements with similar atomic sizes and increasing Young’s modulus,Mo,W,and Re,at 1150℃in(NiCoFeCr)_(92)Al_(3)Ti_(3)M_(2)are,in order of magnitude,D_(MoMo)^(Ni)>D_(WW)^(Ni)>D_(ReRe)^(Ni),as determined by the diffusion-couple experiments.Further investigations on the coarsening kinetics of precipitates confirmed the additions of refractory elements improve the coarsening resistance of γ'pre-cipitates in the order of Re>W>Mo.The trends in the diffusivity determined by experiment and simulation are in excellent agreement.More importantly,the Young’s modulus effect for the diffusion of refractory solutes in HEAs is also carefully analyzed and discussed.Our present findings will give new insights into future design of γ'-strengthened HEAs for high-temperature structural applications. 展开更多
关键词 Refractory solute diffusion High entropy alloys First-principles calculations diffusion couple γ'precipitate coarsening
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In-situ quantitative measurement of phase-sensitive hydrogen diffusion in metals
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作者 Huijun Han Juyeol Baek +6 位作者 Cheolhwan Yoon Yohan Kim Taejun Ha Hayoung Kim Jin-Yoo Suh Jae-Hyeok Shim Hyung-Joon Shin 《Journal of Materials Science & Technology》 2025年第26期279-286,共8页
Absorption and desorption processes of hydrogen in metals are facilitated by alloying elements;however,the formation of secondary phases often reduces storage capacity.The alloying effect on the hydrogen kinetics has ... Absorption and desorption processes of hydrogen in metals are facilitated by alloying elements;however,the formation of secondary phases often reduces storage capacity.The alloying effect on the hydrogen kinetics has been examined by time-lag permeation measurement,which lacks spatial resolution and yields the averaged diffusion coefficient from multiple phases.Here,we report an advanced scanning Kelvin probe force microscopy,combined with in-situ hydrogen loading system for submicron-scale measurement of diffusion kinetics in metals.Successive probing of the surface during hydrogen loading detects the temporal and spatial variations in the surface potential,enabling the estimation of diffusion coefficient.Not only for a single-phase magnesium but also for multiphase titaniumiron based alloys,we can obtain the diffusion coefficients of hydrogen in each phase.The estimated diffusion coefficients for TiFe alloys are higher than that for the pristine TiFe intermetallic compound,due to alloying elements that reduce the diffusion barrier and modify bond character.Our approach paves the way to the microscopic understanding of hydrogen diffusion in metals. 展开更多
关键词 Hydrogen diffusion diffusion coefficients TiFe alloy Hydrogen storage Scanning Kelvin probe force microscopy
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Dielectric-ion-conductive ZnNb_(2)O_(6) layer enabling rapid desolvation and diffusion for dendrite-free Zn metal batteries
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作者 Haifeng Yang Jian Wang +9 位作者 Panpan Zhang Xiaomin Cheng Qinghua Guan Jing Dong Bixian Chen Lujie Jia Jing Zhang Yongzheng Zhang Yunjian Liu Hongzhen Lin 《Journal of Energy Chemistry》 2025年第1期693-701,共9页
Rechargeable aqueous zinc-metal batteries (AZMBs) are promising candidates for large-scale energy storage systems due to their low cost and high safety.However,their performance and sustainability are significantly hi... Rechargeable aqueous zinc-metal batteries (AZMBs) are promising candidates for large-scale energy storage systems due to their low cost and high safety.However,their performance and sustainability are significantly hindered by the sluggish desolvation kinetics at the electrode/electrolyte interface and the corresponding hydrogen evolution reaction where active water molecules tightly participate in the Zn(H_(2)O)_(6)^(2+)solvation shell.Herein,learnt from self-generated solid electrolyte interphase (SEI) in anodes,the dielectric but ion-conductive zinc niobate nanoparticles artificial layer is constructed on metallic Zn surface (ZNB@Zn),acting as a rapid desolvation promotor.The zincophilic and dielectric-conductive properties of ZNB layer accelerate interfacial desolvation/diffusion and suppress surface corrosion or dendrite formation,achieving uniform Zn plating/stripping behavior,as confirmed by electronic/optical microscopies and interface spectroscopical measurements together with theoretical calculations.Consequently,the as-prepared ZNB@Zn electrode exhibits excellent cycling stability of over 2000 h and robust reversibility (99.54%) even under high current density and depth of discharge conditions.Meanwhile,the assembled ZNB@Zn-based full cell displays high capacity-retention rate of 80.21%after 3000 cycles at 5 A g^(-1)and outstanding rate performance up to 10 A g^(-1).The large-areal pouch cell is stabilized for hundreds of cycles,highlighting the bright prospects of the dielectric but ion-conductive layer in further application of AZMBs. 展开更多
关键词 Zn metal battery Dielectri cartificial layer Rapid ion diffusion Zincophilic diffusion Active water inhibition
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New Universal Bounds for Eigenvalues of the Markov Diffusion Operator L2
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作者 Yanli LI Feng DU 《Journal of Mathematical Research with Applications》 2025年第6期745-757,共13页
In this paper,we study the eigenvalue problem of the Markov diffusion operator L^(2),and give generalized inequalities for eigenvalues of the operator L^(2)on a Markov diffusion triple.By applying these inequalities,w... In this paper,we study the eigenvalue problem of the Markov diffusion operator L^(2),and give generalized inequalities for eigenvalues of the operator L^(2)on a Markov diffusion triple.By applying these inequalities,we then get some new universal bounds for eigenvalues of a special Markov diffusion operator L^(2)on bounded domains in an Euclidean space.Moreover,our results can reveal the relationship between the(k+1)-th eigenvalue and the first k eigenvalues in a relatively straightforward manner. 展开更多
关键词 Markov diffusion operator EIGENVALUES universal bounds Markov diffusion triple
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A 3D framework for geological media with multiple intersected fractures:Coupled Darcy flow and Fickian diffusion
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作者 Luyu Wang Weizhong Chen Cornelis Vuik 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第10期6293-6307,共15页
Despite extensive research on computational geomechanics and fluid dynamics,accurately simulating convection-diffusion(CD)processes in complex fractured systems remains a significant challenge.This study develops a 3D... Despite extensive research on computational geomechanics and fluid dynamics,accurately simulating convection-diffusion(CD)processes in complex fractured systems remains a significant challenge.This study develops a 3D numerical framework for modelling CD processes in fractured geological media.The framework integrates Darcy's law and Fick's law,considering flux interactions between the matrix and fractures.The meshing strategy generates high-quality grids even in scenarios involving intersecting fractures.Then,a unified numerical scheme for solving the CD system is proposed.The novelties of this work include:(1)The proposed framework enables effective simulation of 3D fractured media,including more complex fractured vuggy media;(2)The numerical method precisely discretizes the CD terms in governing equations;(3)A Non-Orthogonal Correction(NOC)method,combined with an adaptive time integration scheme,is proposed for eliminating errors induced by skewed grids;and(4)The effects of fracture patterns and heterogeneity on flow are thoroughly analysed.The proposed method is validated through benchmark tests,demonstrating the superiority of the NOC method compared to classical methods.Further analysis reveals the evolution characteristics of pressure and concentration,offering insights into the effects of fracture patterns and heterogeneity on flow and diffusion processes. 展开更多
关键词 Fractured rock masses 3D multiple fractures CONVECTION-diffusION Darcy flow Fickian diffusion
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结合Diffusion-Based WGANGP的变压器油纸绝缘老化状态拉曼光谱检测方法 被引量:1
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作者 陈新岗 敖怡 +5 位作者 张知先 马志鹏 张文轩 万福 况露 罗博文 《光谱学与光谱分析》 北大核心 2025年第8期2164-2173,共10页
提出了一种结合拉曼光谱与扩散模型改进的Wasserstein生成对抗网络(WGANGP)方法,用于提高变压器油纸绝缘老化状态的检测精度。凭借拉曼光谱技术无接触、不损耗的优势,可通过其分析油浸式电力变压器内部油纸绝缘材料的老化产物来评估变... 提出了一种结合拉曼光谱与扩散模型改进的Wasserstein生成对抗网络(WGANGP)方法,用于提高变压器油纸绝缘老化状态的检测精度。凭借拉曼光谱技术无接触、不损耗的优势,可通过其分析油浸式电力变压器内部油纸绝缘材料的老化产物来评估变压器的老化程度。结合深度学习分类模型简化了拉曼光谱数据预处理过程,但此类模型对训练数据的数量和质量有较高要求,由于热加速老化实验周期长,导致可用于训练的有效拉曼光谱数据集相对稀少,限制了分类模型性能。为了解决这一难题,本研究引入了一种新的数据增强方法,即基于扩散模型的WGANGP(Diffusion-Based WGANGP),该方法通过将去噪扩散概率模型的前向加噪过程与WGANGP相结合,向WGANGP中引入实例化的噪声,去除了传统WGANGP的生成器结构中的复杂向上采样过程,简化了数据增强模型结构,有利于模型参数优化。相比于传统GAN及其变体,这种方法不仅保持了变压器油纸绝缘老化样本拉曼光谱数据集的原始特征峰特征与老化程度相关的基线漂移趋势,且与原始数据集特征保持近似的空间分布,生成的数据集信噪比(SNR)为24.84 dB,相比于原始数据集提高了32.11%;同时,也提升了生成样本的多样性,提高了基于深度学习的老化诊断模型的泛化能力、定量分析能力和鲁棒性。实验结果表明,采用Diffusion-Based WGANGP数据增强模型所生成的拉曼光谱数据集,在多个分类模型上的表现均优于其他数据增强方法,特别是在与ResNet-SVM分类模型结合时,在Accuracy(准确性,0.9974)、F1 score(F1分数,0.9969)、Recall(召回率,0.9960)和Precision(精确度,0.9980)四个评价指标上均表现出优势,这表明改进后的数据增强模型能够有效解决变压器老化绝缘油样本稀缺的问题,同时提高了分类模型对变压器老化状态的定量诊断能力。 展开更多
关键词 变压器 油纸绝缘 拉曼光谱 diffusion-Based WGANGP 故障诊断
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