Pub Date : 2026-06-01Epub Date: 2026-01-22DOI: 10.1016/j.optcom.2026.132922
Ajun Shao , Shuting Ma , Xingyu Zhang , Zhuang Zhao , Baohui Guo , Mingze Ma , Jing Han , Yong Peng , Yi Zhang , Lianfa Bai , Guohua Gu , Xin Liu
Near-infrared hyperspectral images (NIR-HSIs, 900–1700 nm) offer rich spectral information and strong haze-penetrating capability, but their performance is often constrained by sensor noise, leading to low signal-to-noise ratio (SNR), diminished contrast, and texture degradation. In contrast, RGB cameras offer higher SNR and richer texture details while being low-cost and widely accessible, thus serving as effective priors to enhance reconstruction of NIR-HSI. This paper propose an RGB-Guided Phase-Aware Hybrid Prior (RGB-PAHP) method within a dual-camera system, where an RGB camera is integrated into a coded aperture snapshot spectral imaging (CASSI) architecture. A multi-scale RGB feature extraction module (RGB-FE) is designed to fully exploit spatial details from RGB images, effectively guiding the reconstruction of NIR-HSI with high SNR. Furthermore, the method employs a deep unfolding network entirely based on multilayer perceptron (MLP), and introduces a Degradation-Aware Residual Gradient Descent (DARGD) module to estimate the residual of the sensing matrix and degradation matrix . The iterative process is divided into shallow spatial–spectral feature extraction and deep texture refinement, balancing reconstruction quality and computational efficiency. Experimental results demonstrate that RGB-PAHP outperforms existing methods in terms of PSNR, SSIM, and SAM, thereby validating its superiority in NIR-HSI reconstruction.
{"title":"RGB-guided phase-aware hybrid prior network for snapshot near-infrared hyperspectral imaging","authors":"Ajun Shao , Shuting Ma , Xingyu Zhang , Zhuang Zhao , Baohui Guo , Mingze Ma , Jing Han , Yong Peng , Yi Zhang , Lianfa Bai , Guohua Gu , Xin Liu","doi":"10.1016/j.optcom.2026.132922","DOIUrl":"10.1016/j.optcom.2026.132922","url":null,"abstract":"<div><div>Near-infrared hyperspectral images (NIR-HSIs, 900–1700 nm) offer rich spectral information and strong haze-penetrating capability, but their performance is often constrained by sensor noise, leading to low signal-to-noise ratio (SNR), diminished contrast, and texture degradation. In contrast, RGB cameras offer higher SNR and richer texture details while being low-cost and widely accessible, thus serving as effective priors to enhance reconstruction of NIR-HSI. This paper propose an RGB-Guided Phase-Aware Hybrid Prior (RGB-PAHP) method within a dual-camera system, where an RGB camera is integrated into a coded aperture snapshot spectral imaging (CASSI) architecture. A multi-scale RGB feature extraction module (RGB-FE) is designed to fully exploit spatial details from RGB images, effectively guiding the reconstruction of NIR-HSI with high SNR. Furthermore, the method employs a deep unfolding network entirely based on multilayer perceptron (MLP), and introduces a Degradation-Aware Residual Gradient Descent (DARGD) module to estimate the residual of the sensing matrix <span><math><mrow><mi>Φ</mi></mrow></math></span> and degradation matrix <span><math><mrow><mover><mi>Φ</mi><mo>ˆ</mo></mover></mrow></math></span>. The iterative process is divided into shallow spatial–spectral feature extraction and deep texture refinement, balancing reconstruction quality and computational efficiency. Experimental results demonstrate that RGB-PAHP outperforms existing methods in terms of PSNR, SSIM, and SAM, thereby validating its superiority in NIR-HSI reconstruction.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132922"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-01-27DOI: 10.1016/j.optcom.2025.132805
Xiang Sui , Ying Shang , Sheng Huang , Wenan Zhao , Xiaohan Qiao , Guangqiang Liu , Chunmei Yao , Shouling Liu , Na Wan , Xianggui Kong , Hong Zhao , Fengming Mou , Zhengying Li , Weitao Wang , Chen Wang , Gangding Peng
{"title":"Corrigendum to “Coherent fading suppression method in the COTDR system based on multi-band filtering” [Opt. Commun. 583 (2025) 131696]","authors":"Xiang Sui , Ying Shang , Sheng Huang , Wenan Zhao , Xiaohan Qiao , Guangqiang Liu , Chunmei Yao , Shouling Liu , Na Wan , Xianggui Kong , Hong Zhao , Fengming Mou , Zhengying Li , Weitao Wang , Chen Wang , Gangding Peng","doi":"10.1016/j.optcom.2025.132805","DOIUrl":"10.1016/j.optcom.2025.132805","url":null,"abstract":"","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132805"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-01-29DOI: 10.1016/j.cjph.2026.01.024
N.D. Pavan , S. Pranesh , P.G. Siddheshwar
This study investigates the linear and weakly nonlinear stability analysis in a Rayleigh-Bénard configuration with a viscoelastic fluid layer influenced by two additional solutal components. The governing equations for both stationary and oscillatory convective regimes, and the critical point at which convection sets in is derived. The comparative analysis is performed for three different viscoelastic fluid models: Oldroyd-B, Maxwell, Rivlin-Ericksen fluid, along with the Newtonian fluid model. In weakly nonlinear stability analysis, a generalized eight-mode Lorenz model is developed that satisfies the general properties of a classical Lorenz model. From this reduced model, the critical points and Hopf-Rayleigh number, representing the initiation of chaos through Hopf bifurcation are determined. The Lyapunov exponents are used to characterize the chaotic, periodic and quasi-periodic motions of the system. The results show that the viscoelastic and triple diffusion parameters affect the initiation of convection and transition to chaos. It is also observed that the Maxwell fluid exhibits the earliest initiation of chaos and the Newtonian fluid the latest, with Oldroyd-B and Rivlin-Ericksen exhibiting intermediate behaviour. The presence of additional solutal concentrations delays the onset of chaotic motion.
{"title":"Chaos in a triple diffusive system involving a viscoelastic fluid layer","authors":"N.D. Pavan , S. Pranesh , P.G. Siddheshwar","doi":"10.1016/j.cjph.2026.01.024","DOIUrl":"10.1016/j.cjph.2026.01.024","url":null,"abstract":"<div><div>This study investigates the linear and weakly nonlinear stability analysis in a Rayleigh-Bénard configuration with a viscoelastic fluid layer influenced by two additional solutal components. The governing equations for both stationary and oscillatory convective regimes, and the critical point at which convection sets in is derived. The comparative analysis is performed for three different viscoelastic fluid models: Oldroyd-B, Maxwell, Rivlin-Ericksen fluid, along with the Newtonian fluid model. In weakly nonlinear stability analysis, a generalized eight-mode Lorenz model is developed that satisfies the general properties of a classical Lorenz model. From this reduced model, the critical points and Hopf-Rayleigh number, representing the initiation of chaos through Hopf bifurcation are determined. The Lyapunov exponents are used to characterize the chaotic, periodic and quasi-periodic motions of the system. The results show that the viscoelastic and triple diffusion parameters affect the initiation of convection and transition to chaos. It is also observed that the Maxwell fluid exhibits the earliest initiation of chaos and the Newtonian fluid the latest, with Oldroyd-B and Rivlin-Ericksen exhibiting intermediate behaviour. The presence of additional solutal concentrations delays the onset of chaotic motion.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"101 ","pages":"Pages 57-79"},"PeriodicalIF":4.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-01-20DOI: 10.1016/j.ultras.2026.107970
Vindhyesh Pandey, S.S. Mishra
Cracks in concrete buildings, pavements and bridges are important signs of structural deterioration and present serious concerns to integrity and safety. Tradionally, manual inspection has been in use to detect the cracks which is labour-intensive, subjective and prone to errors. Recently, researchers have evolved an advanced automated techniques such as YOLO (You Only Look Once), to overcome the manual errors. Continuous refinements have led to the developments of sophisticated versions YOLOv4 to YOLOv11 in the YOLO series. This study suggests a customisation of YOLOv11, for the purpose of its quickness, high accuracy and recall. Using data augmentation, hyperparameter optimisation and transfer learning on a composite dataset of concrete crack images, this model is specifically customized for crack detection. Based on experimental and publicly accessible data like SDNET2018 (Structural Defects Network), this customized version outperforms baseline versions YOLOv5, YOLOv8, YOLOv9, YOLOv10 and YOLOv11. An mAP50 (mean Average Precision) value of 68.6% is achieved which is 3.47% higher as compared to YOLOv11. Similarly, a precision of 80.8% and recall of 63.6% are achieved. The study provides 50, 100, 200, 300 and 400 epochs for training and validation. The 100 layers and 6.3 GFLOPs (Giga Floating Point Operations Per Second) of this model are also very less compared to other given models which is an indicator of less complex model. This model has proved computationally efficient and suitable for real-time applications and robust to challenging conditions such as low contrast and complex backgrounds, making it a valuable tool for structural health monitoring.
混凝土建筑物、路面和桥梁的裂缝是结构恶化的重要标志，对完整性和安全构成严重关切。传统上，人工检查一直用于检测裂缝，这是劳动密集型的，主观的，容易出错。最近，研究人员开发了一种先进的自动化技术，如YOLO (You Only Look Once)，以克服人工错误。不断的改进导致了YOLO系列中复杂版本YOLOv4到YOLOv11的发展。本研究建议对YOLOv11进行定制，以提高其速度、准确性和召回率。在混凝土裂缝图像的复合数据集上使用数据增强、超参数优化和迁移学习，该模型是专门为裂缝检测定制的。基于SDNET2018（结构缺陷网络）等实验和公开可访问的数据，该定制版本优于基准版本YOLOv5， YOLOv8, YOLOv9， YOLOv10和YOLOv11。mAP50 （mean Average Precision）值达到68.6%，比YOLOv11高3.47%。同样，准确率为80.8%，召回率为63.6%。本研究提供了50、100、200、300和400个epoch用于训练和验证。与其他给定模型相比，该模型的100层和6.3 GFLOPs（每秒千兆浮点运算）也非常少，这是一个不太复杂的模型的指标。该模型已被证明具有计算效率，适合实时应用，并且对低对比度和复杂背景等具有挑战性的条件具有鲁棒性，使其成为结构健康监测的宝贵工具。
{"title":"Lightweight frameworks for real-time crack monitoring in civil infrastructure","authors":"Vindhyesh Pandey, S.S. Mishra","doi":"10.1016/j.ultras.2026.107970","DOIUrl":"10.1016/j.ultras.2026.107970","url":null,"abstract":"<div><div>Cracks in concrete buildings, pavements and bridges are important signs of structural deterioration and present serious concerns to integrity and safety. Tradionally, manual inspection has been in use to detect the cracks which is labour-intensive, subjective and prone to errors. Recently, researchers have evolved an advanced automated techniques such as YOLO (You Only Look Once), to overcome the manual errors. Continuous refinements have led to the developments of sophisticated versions YOLOv4 to YOLOv11 in the YOLO series. This study suggests a customisation of YOLOv11, for the purpose of its quickness, high accuracy and recall. Using data augmentation, hyperparameter optimisation and transfer learning on a composite dataset of concrete crack images, this model is specifically customized for crack detection. Based on experimental and publicly accessible data like SDNET2018 (Structural Defects Network), this customized version outperforms baseline versions YOLOv5, YOLOv8, YOLOv9, YOLOv10 and YOLOv11. An mAP50 (mean Average Precision) value of 68.6% is achieved which is 3.47% higher as compared to YOLOv11. Similarly, a precision of 80.8% and recall of 63.6% are achieved. The study provides 50, 100, 200, 300 and 400 epochs for training and validation. The 100 layers and 6.3 GFLOPs (Giga Floating Point Operations Per Second) of this model are also very less compared to other given models which is an indicator of less complex model. This model has proved computationally efficient and suitable for real-time applications and robust to challenging conditions such as low contrast and complex backgrounds, making it a valuable tool for structural health monitoring.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"162 ","pages":"Article 107970"},"PeriodicalIF":4.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-02-11DOI: 10.1016/j.jcp.2026.114756
Senwei Liang , Chunmei Wang , Xingjian Xu
Modeling stochastic differential equations (SDEs) is crucial for understanding complex dynamical systems in various scientific fields. Recent methods often employ neural network-based models, which typically represent SDEs through a combination of deterministic and stochastic terms. However, these models usually lack interpretability and have difficulty in generalizing beyond their training domain. This paper introduces the Finite Expression Method (FEX), a symbolic learning approach designed to derive interpretable mathematical representations of the deterministic component of SDEs. For the stochastic component, we integrate FEX with advanced generative modeling techniques to provide a comprehensive representation of SDEs. The numerical experiments on linear, nonlinear, and multidimensional SDEs demonstrate that FEX generalizes well beyond the training domain and delivers more accurate long-term predictions compared to neural network-based methods. The symbolic expressions identified by FEX not only improve prediction accuracy but also offer valuable scientific insights into the underlying dynamics of the systems.
{"title":"Identifying stochastic dynamics via finite expression methods","authors":"Senwei Liang , Chunmei Wang , Xingjian Xu","doi":"10.1016/j.jcp.2026.114756","DOIUrl":"10.1016/j.jcp.2026.114756","url":null,"abstract":"<div><div>Modeling stochastic differential equations (SDEs) is crucial for understanding complex dynamical systems in various scientific fields. Recent methods often employ neural network-based models, which typically represent SDEs through a combination of deterministic and stochastic terms. However, these models usually lack interpretability and have difficulty in generalizing beyond their training domain. This paper introduces the Finite Expression Method (FEX), a symbolic learning approach designed to derive interpretable mathematical representations of the deterministic component of SDEs. For the stochastic component, we integrate FEX with advanced generative modeling techniques to provide a comprehensive representation of SDEs. The numerical experiments on linear, nonlinear, and multidimensional SDEs demonstrate that FEX generalizes well beyond the training domain and delivers more accurate long-term predictions compared to neural network-based methods. The symbolic expressions identified by FEX not only improve prediction accuracy but also offer valuable scientific insights into the underlying dynamics of the systems.</div></div>","PeriodicalId":352,"journal":{"name":"Journal of Computational Physics","volume":"554 ","pages":"Article 114756"},"PeriodicalIF":3.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-01-20DOI: 10.1016/j.optcom.2026.132917
Yonghong Wang , Zhuoyan Wang , Yanfeng Yao , Junrui Li
To address the problems of fringe merging and loss of fringe edge information during the denoising of high-density fringe patterns in digital speckle pattern interferometry (DSPI), which seriously affects the phase reconstruction and measurement precision, a hierarchical adaptive curvelet thresholding with sine-cosine transform (HACuT) is proposed in this paper. By incorporating subband-wise noise energy estimation in the curvelet domain, local statistical constraints derived from clean image curvelet coefficients, and hierarchical scale-dependent adjustment, an adaptive thresholding scheme is constructed to enable precise and robust regulation of curvelet coefficients. Moreover, a smooth thresholding function based on the hyperbolic tangent is designed to enhance denoising stability. Simulation and experimental results demonstrate that the proposed method effectively suppresses noise, preserves fringe edge integrity, and maintains high computational efficiency, confirming its practical applicability.
{"title":"Multi-scale based approach for denoising digital speckle pattern interferometry fringe patterns using curvelet thresholding","authors":"Yonghong Wang , Zhuoyan Wang , Yanfeng Yao , Junrui Li","doi":"10.1016/j.optcom.2026.132917","DOIUrl":"10.1016/j.optcom.2026.132917","url":null,"abstract":"<div><div>To address the problems of fringe merging and loss of fringe edge information during the denoising of high-density fringe patterns in digital speckle pattern interferometry (DSPI), which seriously affects the phase reconstruction and measurement precision, a hierarchical adaptive curvelet thresholding with sine-cosine transform (HACuT) is proposed in this paper. By incorporating subband-wise noise energy estimation in the curvelet domain, local statistical constraints derived from clean image curvelet coefficients, and hierarchical scale-dependent adjustment, an adaptive thresholding scheme is constructed to enable precise and robust regulation of curvelet coefficients. Moreover, a smooth thresholding function based on the hyperbolic tangent is designed to enhance denoising stability. Simulation and experimental results demonstrate that the proposed method effectively suppresses noise, preserves fringe edge integrity, and maintains high computational efficiency, confirming its practical applicability.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132917"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-01-20DOI: 10.1016/j.optcom.2026.132929
Fanmiao Meng, Weiwei Yu
and are the fundamental models in intense laser field, facilitating the investigation of attosecond electron dynamics, the observation of nuclear wave packet evolution, and the implementation of frequency-modulated high-order harmonic generation. In this work, the high-order harmonic generation dynamics of and , under terahertz field assistance and the nuclear motion, were investigated by using numerical solutions of the non-Born–Oppenheimer time-dependent Schrödinger equation. Terahertz assistance increases the peak intensity of the central electric field while maintaining the shape of the electric field, consequently significantly extending the harmonic cutoff range and generating three distinct plateau regions. Upon considering non-Born–Oppenheimer approximation, the asymmetry of the electron cloud amplifies the interaction between electrons and nuclei, the nuclear motion is relatively slow, so the nuclei remain within the Franck–Condon region. Thus, the efficiency of the harmonic is three orders of magnitude greater than that of . These findings provide new perspectives on the microscopic principles of terahertz-assisted high-order harmonic generation and clarify the impact of nuclear motion on this phenomenon.
{"title":"Investigating the effect of nuclear motion on the high-order harmonic generation efficiency of H2+ and HD+ molecules under terahertz assistance","authors":"Fanmiao Meng, Weiwei Yu","doi":"10.1016/j.optcom.2026.132929","DOIUrl":"10.1016/j.optcom.2026.132929","url":null,"abstract":"<div><div><span><math><msubsup><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math></span> and <span><math><msup><mrow><mi>HD</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span> are the fundamental models in intense laser field, facilitating the investigation of attosecond electron dynamics, the observation of nuclear wave packet evolution, and the implementation of frequency-modulated high-order harmonic generation. In this work, the high-order harmonic generation dynamics of <span><math><msubsup><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math></span> and <span><math><msup><mrow><mi>HD</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span>, under terahertz field assistance and the nuclear motion, were investigated by using numerical solutions of the non-Born–Oppenheimer time-dependent Schrödinger equation. Terahertz assistance increases the peak intensity of the central electric field while maintaining the shape of the electric field, consequently significantly extending the harmonic cutoff range and generating three distinct plateau regions. Upon considering non-Born–Oppenheimer approximation, the asymmetry of the electron cloud amplifies the interaction between electrons and nuclei, the nuclear motion is relatively slow, so the nuclei remain within the Franck–Condon region. Thus, the efficiency of the <span><math><msubsup><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msubsup></math></span> harmonic is three orders of magnitude greater than that of <span><math><msup><mrow><mi>HD</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span>. These findings provide new perspectives on the microscopic principles of terahertz-assisted high-order harmonic generation and clarify the impact of nuclear motion on this phenomenon.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"607 ","pages":"Article 132929"},"PeriodicalIF":2.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-02-04DOI: 10.1016/j.dark.2026.102243
Reggie C. Pantig , Ali Övgün , Gaetano Lambiase
We explore the weak-field phenomenology of a compact star spacetime modified by quantum gravitational corrections derived from the effective field theoretical (EFT) approach by Calmet et al. [1]. These corrections, encoded in non-local curvature-squared terms, distinguish matter-supported geometries from vacuum solutions by contributing nontrivial modifications at order O(G2). Using the corrected metric, we analytically derive expressions for the deflection of light and time-like particles via the Gauss-Bonnet theorem. We further compute the perihelion advance of Mercury, Shapiro time delay, and gravitational redshift within this framework. Each classical observable acquires quantum corrections that, though exceedingly small (on the order of arcsecond per century for perihelion precession and arcsecond for light deflection) represent potential imprints of quantum gravity. The Shapiro delay and redshift likewise exhibit finite, source-dependent deviations from their general relativistic predictions due to the modified temporal metric component. While current observational capabilities remain insufficient to detect these minute effects, the analysis demonstrates that quantum gravitational signatures are embedded even in weak-field observables. Last, we study massless scalar perturbations in static, spherically symmetric spacetimes by analyzing their quasinormal modes (QNMs) and greybody factors using the WKB method and Pade resummation. Our findings demonstrate that increasing the coupling parameter enhances spacetime stability and significantly influences emission spectra through frequency-dependent transparency. Moreover, the results underscore that quantum-corrected star metrics yield phenomenological distinctions from classical black holes, particularly near the Planck scale, where vacuum solutions lose validity.
{"title":"Probing quantum gravity in stellar spacetimes: Phenomenological insights","authors":"Reggie C. Pantig , Ali Övgün , Gaetano Lambiase","doi":"10.1016/j.dark.2026.102243","DOIUrl":"10.1016/j.dark.2026.102243","url":null,"abstract":"<div><div>We explore the weak-field phenomenology of a compact star spacetime modified by quantum gravitational corrections derived from the effective field theoretical (EFT) approach by Calmet et al. [1]. These corrections, encoded in non-local curvature-squared terms, distinguish matter-supported geometries from vacuum solutions by contributing nontrivial modifications at order <em>O</em>(<em>G</em><sup>2</sup>). Using the corrected metric, we analytically derive expressions for the deflection of light and time-like particles via the Gauss-Bonnet theorem. We further compute the perihelion advance of Mercury, Shapiro time delay, and gravitational redshift within this framework. Each classical observable acquires quantum corrections that, though exceedingly small (on the order of <span><math><msup><mn>10</mn><mrow><mo>−</mo><mn>9</mn></mrow></msup></math></span> arcsecond per century for perihelion precession and <span><math><msup><mn>10</mn><mrow><mo>−</mo><mn>18</mn></mrow></msup></math></span> arcsecond for light deflection) represent potential imprints of quantum gravity. The Shapiro delay and redshift likewise exhibit finite, source-dependent deviations from their general relativistic predictions due to the modified temporal metric component. While current observational capabilities remain insufficient to detect these minute effects, the analysis demonstrates that quantum gravitational signatures are embedded even in weak-field observables. Last, we study massless scalar perturbations in static, spherically symmetric spacetimes by analyzing their quasinormal modes (QNMs) and greybody factors using the WKB method and Pade resummation. Our findings demonstrate that increasing the coupling parameter enhances spacetime stability and significantly influences emission spectra through frequency-dependent transparency. Moreover, the results underscore that quantum-corrected star metrics yield phenomenological distinctions from classical black holes, particularly near the Planck scale, where vacuum solutions lose validity.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"52 ","pages":"Article 102243"},"PeriodicalIF":6.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-02-10DOI: 10.1016/j.optlastec.2026.114838
Houxiao Wang , Jilong Li , Wuhong Xin
More and more structural members have been fabricated by using the premium aluminum alloy 7075 (AA7075) because of its excellent properties such as ultra high strength and very high specific strength. However, the AA7075 is a difficult-to-clad material, which usually can not meet the harsh long-term service requirements for the corrosive environments and/or under the wear working conditions. Accordingly, in this study, the novel FeAl50CrNi composite powder, which is the Fe-Al based alloy cladding powder properly mixed by SS304, Fe60 and Al with a recommended weight percent ratio of 2:3:5, is first reported based on the composition ratio design, comparison and proper selection. Assisted by preheating and heat preservation, the FeAl50CrNi composite powder was utilized for carrying out laser cladding experiments on the AA7075 plate surfaces via altering key laser parameters. It was indicated that the challenging problems (e.g., serious occurrence of cracks and pores, incomplete melt, slag entrapment, as well as poor interface fusion and joining) usually encountered during laser cladding for aluminum alloys were concurrently well solved by using the newly-developed composite cladding powder, as well as preferred defocus distance of −5 mm, focal spot diameter of 4.5 mm, and laser power of 1600 W. That is to say, the high-quality FeAl50CrNi composite coatings, which were well melted, mixed, fused and then metallurgically and reliably bound onto the AA7075 plate surfaces, were successfully achieved nearly without cladding defects by using laser cladding in this work. As compared to the AA7075 substrate, the wear resistance and corrosion resistance of laser cladded high-quality FeAl50CrNi composite coatings were improved concurrently and effectively by using a proper laser power of 1600 W. Such improvements achieved were reported in terms of a maximum micro hardness improvement of 116.67%, an averaged friction coefficient reduction of 31.43%, a wear loss reduction of 77.66% during half an hour, and a reduction of 31.23% in corrosion current density. As demonstrated, as a result of the notable alterations in terms of the effective energy inputs, laser fluences, heating–cooling rates and element diffusion, the microstructure characteristics notably altered from the coating top to the fusion zone inside the laser cladded area. Interestingly, these internal coating microstructure changes were characterized primarily by means of the dispersively distributed acicular Fe-Al intermetallic compounds (coating top), the dispersively distributed tiny second phase particles (coating middle), and the fine equiaxed and columnar grains (fusion zone). Importantly, such microstructure characteristics made the coatings possess the overall good mechanical performance in strength, ductility and toughness, micro hardness, wear resistance and corrosion resistance.
{"title":"Laser cladding of crack-free reliably-joined FeAl50CrNi composite coatings with minimized porosity and improved microstructure to notably enhance electrochemical corrosion plus wear resistance for aluminum alloy 7075 plate surfaces","authors":"Houxiao Wang , Jilong Li , Wuhong Xin","doi":"10.1016/j.optlastec.2026.114838","DOIUrl":"10.1016/j.optlastec.2026.114838","url":null,"abstract":"<div><div>More and more structural members have been fabricated by using the premium aluminum alloy 7075 (AA7075) because of its excellent properties such as ultra high strength and very high specific strength. However, the AA7075 is a difficult-to-clad material, which usually can not meet the harsh long-term service requirements for the corrosive environments and/or under the wear working conditions. Accordingly, in this study, the novel FeAl50CrNi composite powder, which is the Fe-Al based alloy cladding powder properly mixed by SS304, Fe60 and Al with a recommended weight percent ratio of 2:3:5, is first reported based on the composition ratio design, comparison and proper selection. Assisted by preheating and heat preservation, the FeAl50CrNi composite powder was utilized for carrying out laser cladding experiments on the AA7075 plate surfaces via altering key laser parameters. It was indicated that the challenging problems (e.g., serious occurrence of cracks and pores, incomplete melt, slag entrapment, as well as poor interface fusion and joining) usually encountered during laser cladding for aluminum alloys were concurrently well solved by using the newly-developed composite cladding powder, as well as preferred defocus distance of −5 mm, focal spot diameter of 4.5 mm, and laser power of 1600 W. That is to say, the high-quality FeAl50CrNi composite coatings, which were well melted, mixed, fused and then metallurgically and reliably bound onto the AA7075 plate surfaces, were successfully achieved nearly without cladding defects by using laser cladding in this work. As compared to the AA7075 substrate, the wear resistance and corrosion resistance of laser cladded high-quality FeAl50CrNi composite coatings were improved concurrently and effectively by using a proper laser power of 1600 W. Such improvements achieved were reported in terms of a maximum micro hardness improvement of 116.67%, an averaged friction coefficient reduction of 31.43%, a wear loss reduction of 77.66% during half an hour, and a reduction of 31.23% in corrosion current density. As demonstrated, as a result of the notable alterations in terms of the effective energy inputs, laser fluences, heating–cooling rates and element diffusion, the microstructure characteristics notably altered from the coating top to the fusion zone inside the laser cladded area. Interestingly, these internal coating microstructure changes were characterized primarily by means of the dispersively distributed acicular Fe-Al intermetallic compounds (coating top), the dispersively distributed tiny second phase particles (coating middle), and the fine equiaxed and columnar grains (fusion zone). Importantly, such microstructure characteristics made the coatings possess the overall good mechanical performance in strength, ductility and toughness, micro hardness, wear resistance and corrosion resistance.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"198 ","pages":"Article 114838"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-06-01Epub Date: 2026-02-14DOI: 10.1016/j.optlastec.2026.114929
Kuo Yang, Ruihuan Wu, Weiyi Hong, Hongzhan Liu
A novel method for generating short microwave pulse trains based on a coupled signal mode-locked optoelectronic oscillator (CML-OEO) is proposed and experimentally demonstrated. In the proposed system, a coupled signal composed of two square-wave signals serves as the mode-locking signal to periodically manipulate the intracavity gain of the OEO. The pulse width of the output pulse trains can be flexibly adjusted by tuning the phase difference between the square-wave signals. This mechanism provides a means for effective pulse compression. The experimental results indicate that CML-OEO generates short microwave pulse trains with a repetition frequency of 195.005 kHz through fundamental frequency mode locking. Compared to the traditional active mode-locked optoelectronic oscillator, the CML-OEO achieves pulse compression effects of 73.0%.
{"title":"Generation of short microwave pulse trains based on coupled signal mode-locked optoelectronic oscillator","authors":"Kuo Yang, Ruihuan Wu, Weiyi Hong, Hongzhan Liu","doi":"10.1016/j.optlastec.2026.114929","DOIUrl":"10.1016/j.optlastec.2026.114929","url":null,"abstract":"<div><div>A novel method for generating short microwave pulse trains based on a coupled signal mode-locked optoelectronic oscillator (CML-OEO) is proposed and experimentally demonstrated. In the proposed system, a coupled signal composed of two square-wave signals serves as the mode-locking signal to periodically manipulate the intracavity gain of the OEO. The pulse width of the output pulse trains can be flexibly adjusted by tuning the phase difference between the square-wave signals. This mechanism provides a means for effective pulse compression. The experimental results indicate that CML-OEO generates short microwave pulse trains with a repetition frequency of 195.005 kHz through fundamental frequency mode locking. Compared to the traditional active mode-locked optoelectronic oscillator, the CML-OEO achieves pulse compression effects of 73.0%.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"198 ","pages":"Article 114929"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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