物理与天体物理最新文献

{"title":"Mamba time series forecasting with uncertainty quantification.","authors":"Pedro Pessoa, Paul Campitelli, Douglas P Shepherd, S Banu Ozkan, Steve Pressé","doi":"10.1088/2632-2153/adec3b","DOIUrl":"10.1088/2632-2153/adec3b","url":null,"abstract":"<p><p>State space models, such as Mamba, have recently garnered attention in time series forecasting (TSF) due to their ability to capture sequence patterns. However, in electricity consumption benchmarks, Mamba forecasts exhibit a mean error of approximately 8%. Similarly, in traffic occupancy benchmarks, the mean error reaches 18%. This discrepancy leaves us to wonder whether the prediction is simply inaccurate or falls within error given spread in historical data. To address this limitation, we propose a method to quantify the predictive uncertainty of Mamba forecasts. To achieve this, we propose a dual-network framework based on the Mamba architecture for probabilistic forecasting, where one network generates point forecasts while the other estimates predictive uncertainty by modeling variance. We abbreviate our tool, Mamba with probabilistic TSF, as Mamba-ProbTSF and the code for its implementation is available on GitHub https://github.com/PessoaP/Mamba-ProbTSF. Evaluating this approach on synthetic and real-world benchmark datasets, we find Kullback-Leibler divergence between the learned distributions and the data-which, in the limit of infinite data, should converge to zero if the model correctly captures the underlying probability distribution-reduced to the order of 10^-3 for synthetic data and 10^-1 for real-world benchmark. We find that in both the electricity consumption and traffic occupancy benchmark, the true trajectory stays within the predicted uncertainty interval at the two-sigma level about 95% of the time. We further compare Mamba-ProbTSF against leading probabilistic forecast methods, DeepAR and ARIMA, and show that our method consistently achieves lower forecast errors while offering more reliable uncertainty quantification. We end with a consideration of potential limitations, adjustments to improve performance, and considerations for applying this framework to processes for purely or largely stochastic dynamics where the stochastic changes accumulate as observed, for example, in pure Brownian motion or molecular dynamics trajectories.</p>","PeriodicalId":33757,"journal":{"name":"Machine Learning Science and Technology","volume":"6 3","pages":"035012"},"PeriodicalIF":6.3,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12281171/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144699735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond Euclid: an illustrated guide to modern machine learning with geometric, topological, and algebraic structures.","authors":"Mathilde Papillon, Sophia Sanborn, Johan Mathe, Louisa Cornelis, Abby Bertics, Domas Buracas, Hansen J Lillemark, Christian Shewmake, Fatih Dinc, Xavier Pennec, Nina Miolane","doi":"10.1088/2632-2153/adf375","DOIUrl":"10.1088/2632-2153/adf375","url":null,"abstract":"<p><p>The enduring legacy of Euclidean geometry underpins classical machine learning, which, for decades, has been primarily developed for data lying in Euclidean space. Yet, modern machine learning increasingly encounters richly structured data that is inherently non-Euclidean. This data can exhibit intricate geometric, topological and algebraic structure: from the geometry of the curvature of space-time, to topologically complex interactions between neurons in the brain, to the algebraic transformations describing symmetries of physical systems. Extracting knowledge from such non-Euclidean data necessitates a broader mathematical perspective. Echoing the 19th-century revolutions that gave rise to non-Euclidean geometry, an emerging line of research is redefining modern machine learning with non-Euclidean structures. Its goal: generalizing classical methods to unconventional data types with geometry, topology, and algebra. In this review, we provide an accessible gateway to this fast-growing field and propose a graphical taxonomy that integrates recent advances into an intuitive unified framework. We subsequently extract insights into current challenges and highlight exciting opportunities for future development in this field.</p>","PeriodicalId":33757,"journal":{"name":"Machine Learning Science and Technology","volume":"6 3","pages":"031002"},"PeriodicalIF":4.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12315666/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144776367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hyperbaric underwater laser welding of 10CrNi3MoV high-strength low-alloy steel: Influence of ambient pressure on weld formation, microstructure and mechanical properties","authors":"Congwei Li ,&nbsp;Jialei Zhu ,&nbsp;Caiyou Zeng ,&nbsp;Rongkui Kou ,&nbsp;Caiyan Deng ,&nbsp;Lei Cui ,&nbsp;Xiangdong Jiao","doi":"10.1016/j.optlastec.2025.113733","DOIUrl":"10.1016/j.optlastec.2025.113733","url":null,"abstract":"<div><div>An in-situ hyperbaric underwater laser welding (HULW) technology is proposed for the difficulty of underwater emergency repair of ships during ocean voyages. The influence law of HULW process within the pressure range up to 0.4 MPa for 10CrNi3MoV high strength low alloy (HSLA) steel was investigated. It was found that the ambient pressure increased from 0.1 MPa to 0.4 MPa: weld penetration depth decreased by 17.95 %, bead width reduced by 12.50 %, reinforcement height increased by 13.77 %, and the forming quality deteriorated. The shielding effect of plasma is enhanced under high pressure and the laser energy is attenuated. By regulating the welding heat input, the loss of laser energy under different pressures can be increased to optimise the weld shape and performance. The welded joints were analyzed using material characterization and testing methods, and the results showed that the original weld microstructure mainly consists of proeutectoid ferrite and various types of carbide microstructures. Elevated pressure in the welding environment, the bainite content on the weld metal(WM) gradually increases, the coarse grain zone microstructure becomes coarsened, the martensite content increases, and the amount of pearlite in the fine grain zone decreases significantly. With the increase of ambient pressure, the hardness of both HAZ and WM increased. As the ambient pressure increased from 0.1 MPa to 0.4 MPa, the transverse tensile strength decreased by 79 MPa, Charpy impact absorption energy by<!--> <!-->6.42 % at 25℃<!--> <!-->and<!--> <!-->7.14 % at −60℃.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113733"},"PeriodicalIF":5.0,"publicationDate":"2025-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144858209","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}

{"title":"Measurement of plutonium in surface modern corals by accelerator mass spectrometry","authors":"Huijuan Wang ,&nbsp;Xianyu Zhan ,&nbsp;Ming He ,&nbsp;Qingzhang Zhao ,&nbsp;Hua He ,&nbsp;Zhiyong Liu ,&nbsp;Mario De Cesare ,&nbsp;Jingyu Mai ,&nbsp;Chunping Huang ,&nbsp;Yongjing Guan","doi":"10.1016/j.nimb.2025.165827","DOIUrl":"10.1016/j.nimb.2025.165827","url":null,"abstract":"<div><div>To investigate the activity concentration and source of plutonium near Weizhou island in the Beibu Gulf, China, plutonium isotopes in different surface coral species were analyzed. The measured ²³⁹Pu activity concentrations in coral samples ranged from 3.12 to 19.93 mBq/kg. The statistically indistinguishable<!--> ²⁴⁰Pu/²³⁹Pu atomic ratios observed in coral skeletons (0.203 ± 0.004) and ambient seawater (0.202 ± 0.003), which contrast significantly with sediment ratios (0.221 ± 0.015). The ²⁴⁰Pu/²³⁹Pu atomic ratios (0.173–0.225) indicate that the plutonium deposition predominantly originates from global atmospheric fallout, with an estimated average 18 % contribution from the Pacific Proving Grounds.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"567 ","pages":"Article 165827"},"PeriodicalIF":1.4,"publicationDate":"2025-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144858372","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}

{"title":"Tunable single-mode two-section semiconductor lasers with photolithography-patterned low-order surface gratings","authors":"Biwei Hu ,&nbsp;Zhunhao Hu ,&nbsp;Zhong Dong ,&nbsp;Youling Chen ,&nbsp;Jinlong Xiao ,&nbsp;Yongzhen Huang ,&nbsp;Yuede Yang","doi":"10.1016/j.optlastec.2025.113744","DOIUrl":"10.1016/j.optlastec.2025.113744","url":null,"abstract":"<div><div>Low-cost single-mode semiconductor lasers are critical optoelectronic components for optical communication networks. Here, we demonstrate wavelength-tunable single-mode two-section semiconductor lasers. These lasers incorporate optimized low-order surface gratings, fabricated using I-line projection photolithography without requiring epitaxial regrowth. The grating parameters are carefully balanced for simultaneous low optical loss and high reflectivity, thereby directly enhancing device performance. The fabricated laser achieves a maximum side-mode suppression ratio (SMSR) exceeding 58 dB. It maintains stable single-mode operation with an SMSR &gt;50 dB over a 30-mA current-tuning range without mode hopping. Notably, independent current biasing of the two sections enables continuous wavelength tuning over 8.2 nm, highlighting robust tunability. Additionally, the laser delivers an output power exceeding 14 mW and demonstrates a 3-dB modulation bandwidth greater than 10 GHz.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113744"},"PeriodicalIF":5.0,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144851943","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}

{"title":"SC-FPP: breaking 1 kHz frame-rate limits of 3D reconstruction with industrial cameras via snapshot compressive fringe projection profilometry","authors":"Xichun Liu ,&nbsp;Dawei Tang ,&nbsp;Jun Zhang ,&nbsp;Jian Wang ,&nbsp;Wei Guo ,&nbsp;Shan Lou ,&nbsp;Wenhan Zeng ,&nbsp;Jinlong Zhu ,&nbsp;Shiyuan Liu ,&nbsp;Xiangqian Jiang","doi":"10.1016/j.optlastec.2025.113757","DOIUrl":"10.1016/j.optlastec.2025.113757","url":null,"abstract":"<div><div>Fringe projection profilometry (FPP) is constrained by the synchronization mechanism of projector-camera pairs, limiting its application in high-spatiotemporal-resolution scenarios, such as additive manufacturing molten pool monitoring and dynamic testing. Specifically, the 3D reconstruction frame rate of FPP is limited by the camera transmission bandwidth and the length of projection sequence required for unambiguous phase retrieval: an <span><math><mi>f</mi></math></span> Hz industrial camera typically achieves up to only <span><math><mrow><mi>f</mi><mo>/</mo><mi>P</mi></mrow></math></span> Hz 3D imaging (<span><math><mi>P</mi></math></span> is the projection sequence length). This frame-rate loss restricts industrial monitoring to ∼100 Hz. To address the problem, we propose the snapshot compressive FPP (SC-FPP), a high-speed 3D imaging method that integrates FPP with snapshot compressive imaging (SCI). By employing random spatial optical field encoding and subsequent fringe images recovery, SC-FPP enables high-resolution 3D imaging at up to <span><math><mrow><mi>Bf</mi><mo>/</mo><mi>P</mi></mrow></math></span> Hz (<span><math><mi>B</mi></math></span> is the compression ratio). Hybrid simulation experiment results show that SC-FPP enables 3D imaging at over 1 kHz using an industrial camera by setting <span><math><mrow><mi>B</mi><mo>=</mo><mi>P</mi></mrow></math></span>. At the same time, accuracy validation further demonstrates that SC-FPP delivers superior measurement precision, reaching an RMSE of 36.6 <span><math><mi>μ</mi><mi>m</mi></math></span> in standard sphere tests. This method breaks through the hardware frame-rate limit of industrial cameras, providing a low-cost, high-performance solution for in-process high-speed 3D monitoring.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113757"},"PeriodicalIF":5.0,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144851944","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}

{"title":"First Protactinium-231 measurements using the MILEA AMS system","authors":"Janis Wolf ,&nbsp;Marcus Christl ,&nbsp;Sebastian Fichter ,&nbsp;Robin Steudtner ,&nbsp;Habacuc Perez Tribouillier ,&nbsp;Stella Winkler ,&nbsp;Anton Wallner","doi":"10.1016/j.nimb.2025.165824","DOIUrl":"10.1016/j.nimb.2025.165824","url":null,"abstract":"<div><div>We present an AMS-based method for measuring <span><math><mrow><mn>231</mn><mi>Pa</mi></mrow></math></span> at natural levels in environmental samples. A chemical procedure extracts <span><math><mrow><mn>231</mn><mi>Pa</mi></mrow></math></span> from sea sediments using <span><math><mrow><mn>233</mn><mi>Pa</mi></mrow></math></span> as a reference isotope. <span><math><mrow><mn>233</mn><mi>Pa</mi></mrow></math></span> was separated from its mother-nuclide <span><math><mrow><mn>237</mn><mi>Np</mi></mrow></math></span> via single-step extraction chromatography. AMS measurements at the Multi-Isotope-Low-Energy AMS System (MILEA) at ETH Zürich showed no interference from <span><math><mrow><mn>232</mn><mi>Th</mi></mrow></math></span>. We determined a <span><math><mrow><mn>231</mn><mi>Pa</mi></mrow></math></span> concentration of (3.6 ± 0.6) × 10⁹ <!-->atoms/g in the IAEA-385 reference material (Irish Sea sediment). We report on the development and implementation of a measurement procedure for <span><math><mrow><mn>231</mn><mi>Pa</mi></mrow></math></span> AMS, demonstrating its potential for ultra-trace environmental studies.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"567 ","pages":"Article 165824"},"PeriodicalIF":1.4,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852767","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}

{"title":"Multiple defects localization method for multi-directional CFRP laminates based on acoustic ray tracing and kernel density estimation algorithm","authors":"Haosen Gu ,&nbsp;Hongjuan Yang ,&nbsp;Zhengyan Yang ,&nbsp;Shuyi Ma ,&nbsp;Jiaqi Zhang ,&nbsp;Zhanjun Wu ,&nbsp;Yinan Shan","doi":"10.1016/j.apacoust.2025.111010","DOIUrl":"10.1016/j.apacoust.2025.111010","url":null,"abstract":"<div><div>Due to the anisotropic property and multi-layer structure of carbon fiber reinforced plastics (CFRP), the calculation time of the acoustic propagation path increases, which reduces the efficiency of damage detection. This paper proposes a defect localization method for CFRP laminates based on acoustic ray tracing and a kernel density estimation algorithm. Potential defect reflection points are generated using the travel times of the defect-scattered signals from different transmitter–receiver array element pairs. The defect position is determined by identifying the central position of these points via kernel density estimation. Simulation and experiment of defect localization were carried out for a through-hole defect or multiple delamination defects in a multi-directional CFRP laminate with a thickness of 6.4 mm. The results demonstrate that the proposed ultrasonic localization method enables high-accuracy and high-efficiency detection and localization of defects in multi-directional CFRP plates.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"241 ","pages":"Article 111010"},"PeriodicalIF":3.4,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852900","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}

{"title":"Flow-cell cooled dissipation for hundreds of watts laser lighting with high color rendering index","authors":"Yiwei Zhu ,&nbsp;Yang Li ,&nbsp;Jun Zou ,&nbsp;Lichao Wang ,&nbsp;Qi Chen ,&nbsp;Jian Kang ,&nbsp;Cen Shao ,&nbsp;Le Zhang","doi":"10.1016/j.optlastec.2025.113768","DOIUrl":"10.1016/j.optlastec.2025.113768","url":null,"abstract":"<div><div>When irradiated by a high-power laser, a large amount of heat accumulates on the surface of phosphors. Ultra-high brightness, hundred-watt power laser lighting faces a critical challenge in solving problems of thermal damage and thermal quenching due to the heat accumulation. Therefore, the efficient heat dissipation of phosphors is the key to achieving stable output of hundred-watt lighting sources. Herein, a transmissive water-cooling device is designed and fabricated. Most of the heat generated during the phosphor conversion process is carried away by the water flow, reducing the working temperature of phosphors. Benefiting from the efficient heat dissipation of this water-cooling device, both inorganic phosphor and organic phosphor-in-silicone can withstand blue laser excitation exceeding 100 W while the operating temperature is maintained below 100 °C. Using this transmissive water-cooling device, a laser lighting source based on phosphor ceramic-film color converters is encapsulated. At an excitation power of 123.5 W, a white light output of 12,061 lm with a high CRI of 89 is achieved. This work provides new insights into advancing high-color-rendering high-power laser lighting source technology.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113768"},"PeriodicalIF":5.0,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852054","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}

{"title":"Development of a low-intensity-noise laser source based on ultra-low-noise photodetectors in the sub-millihertz band","authors":"Fan Li ,&nbsp;Long Tian ,&nbsp;Tianshi Huang ,&nbsp;Hao Dang ,&nbsp;Desheng Zhao ,&nbsp;Shaoping Shi ,&nbsp;Yajun Wang ,&nbsp;Wangbao Yin ,&nbsp;Yaohui Zheng","doi":"10.1016/j.optlastec.2025.113747","DOIUrl":"10.1016/j.optlastec.2025.113747","url":null,"abstract":"<div><div>Space-borne gravitational wave observatories (GWOs) necessitate exceptionally low relative intensity noise (RIN) and ultra-stable laser sources, which can be developed via active optoelectronic feedback loops relying on low-noise optoelectronic elements in 0.1 mHz to 1 Hz band. As a primary component in photoelectric signal conversion, the photodetector (PD)’s performance directly influences the characteristics of the optoelectronic feedback loop. To achieve the laser-power stability required for space-borne GWOs, our analysis introduces a theoretical noise model for the PD, enabling the determination of its critical performance parameters. Based on an analysis of photodiode dark-current noise mechanisms, we optimize the operating temperature and select the optimal operating mode, achieving a dramatic reduction in dark-current noise. Then, we employ a chopper-stabilized operational amplifier to suppress 1/f noise generated by the transimpedance amplifier circuit. Experimental results demonstrate a static noise floor below 1.2 × 10⁻⁶ V/√Hz in the 0.1 mHz to 1 Hz band. By employing this low-noise PD, a low-RIN laser is successfully realized. Specifically, during a continuous 3-hour laser power stabilization test, it achieves an Allan deviation of 6 × 10⁻⁷ at 1 s. Meanwhile, in the frequency band from 0.1 mHz to 1 Hz, the out-of-loop RIN is maintained below 6 × 10⁻⁵ /√Hz. The results provide both an experimental validation and a critical technical foundation for implementing highly stable laser systems in the sub-millihertz frequency band.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113747"},"PeriodicalIF":5.0,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852050","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}