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2606.10437 2026-06-10 physics.app-ph physics.data-an 新提交

Virtual-Array Operational Modal Analysis of Rolling Tires Using a Single Tire Cavity Accelerometer

使用单个轮胎空腔加速度计进行滚动轮胎的虚拟阵列运行模态分析

Pradosh Pritam Dash, Ricardo Burdisso, Pablo A Tarazaga

AI总结 提出利用单个无线轮胎空腔加速度计和两个光学传感器,通过非整数直径比创建虚拟传感器阵列,结合阶次跟踪和随机子空间识别方法,成功识别滚动轮胎240Hz以下的11个周向模态,实现高效低成本的车轮动力学表征。

Comments Manuscript-Based on Master's Thesis, Virginia Tech, 2020, http://hdl.handle.net/10919/107874

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AI中文摘要

滚动轮胎的动力学显著影响车辆内部低频(0-500 Hz)结构噪声。在真实运行条件下准确表征这些动力学仍然具有挑战性。当前最先进的方法主要依赖激光多普勒测振仪(LDV),实施复杂、耗时,且由于胎面表面散斑形成问题,通常仅限于实验室环境中的光滑轮胎。本研究引入了一种创新策略,使用单个无线轮胎空腔加速度计(TCA)和两个光学传感器对滚动轮胎进行运行模态分析(OMA)。该方法利用试验台上轮胎与滚筒直径的非整数比创建虚拟传感器阵列。通过光学传感器精确标记滚筒上障碍物冲击的时间戳和轮胎上TCA的位置,将多次旋转的振动响应根据冲击时刻TCA的周向位置进行聚类,从而有效合成来自分布在轮胎圆周上的虚拟传感器阵列的响应,仅使用单次测试运行的数据。聚类信号通过阶次跟踪处理,去除接触斑变形引起的周期性分量。采用频域分解(FDD)和基于协方差的随机子空间识别(SSI-Cov)进行模态识别。SSI-Cov方法更为稳健,成功识别了高达240 Hz的11个周向模态。所提出的方法为表征滚动轮胎动力学提供了一种显著更高效、成本更低的途径,易于应用于有胎面轮胎,并适用于道路测试。

英文摘要

The dynamics of rolling tires significantly influence the low-frequency (0-500 Hz) structure-borne noise within vehicles. Accurately characterizing these dynamics under realistic operating conditions remains challenging. Current state-of-the-art methods, primarily relying on Laser Doppler Vibrometers (LDV), are complex to implement, time-intensive, and generally limited to smooth tires in laboratory environments due to issues with speckle formation on treaded surfaces. This study introduces an innovative strategy for Operational Modal Analysis (OMA) of a rolling tire using a single wireless Tire Cavity Accelerometer (TCA) together with two optical sensors. The methodology leverages the non-integer ratio between the tire and drum diameters in a test rig to create a virtual sensor array. By utilizing optical sensors to time-stamp the cleat impact (on the drum) precisely and the TCA position (on the tire), the vibration responses from multiple revolutions are clustered according to the TCA's circumferential position at the moment of impact. This effectively synthesizes responses from an array of virtual sensors distributed around the tire circumference using data from a single test run. The clustered signals are conditioned using order tracking to remove periodic components arising from contact patch deformation. Both Frequency Domain Decomposition (FDD) and Covariance-based Stochastic Subspace Identification (SSI-Cov) were employed for modal identification. The SSI-Cov method proved more robust, successfully identifying 11 circumferential modes up to 240 Hz. The proposed approach offers a significantly more efficient, cost-effective method for characterizing rolling tire dynamics, which is readily applicable to treaded tires and adaptable for on-road testing.

2606.10433 2026-06-10 physics.hist-ph 新提交

At the Origins of Electroculture: A Retrodictive Modelling of Bertholon's 18th-Century Electrovegetometer in the Pre-Corona Regime

电栽培的起源:贝托隆18世纪电植被计在预电晕状态下的回溯建模

Thierry Dufour

AI总结 通过二维准稳态欧姆模型,量化了贝托隆电植被计在晴空和风暴条件下对近冠层电场和离子通量的增强作用,发现晴空影响微弱且局部,风暴下可能产生电晕,但农业效应有限。

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Journal ref
Compte-Rendus Mécanique de l'Académie des Sciences. Volume 354 (2026), p. 117-139
AI中文摘要

皮埃尔-尼古拉·贝托隆在18世纪设计的电植被计旨在利用“大气电”促进植物生长,但其物理能力从未在当今对地球大气电系统理解的背景下被量化。本研究解决了对这种历史“电栽培”装置及其对近冠层电环境可能影响的定量评估缺失问题。它旨在利用当代大气电动力学重新解释贝托隆的装置,询问在何种现实的晴空和类风暴条件下,一个纯被动收集-分配器能产生具有物理意义的电场和离子通量。开发了一个二维准稳态欧姆模型,其中大气是承载全球传导电流的电阻柱,金属结构是由漏电木质绝缘体支撑的浮动导体,并排除空间电荷和电晕,因此所有结果描述的是预电晕状态的上限。模拟显示,在晴空条件下,电植被计的单上点和下多点冠将背景场增强两到三个数量级,但仅限于尖端周围毫米至厘米区域,总电流限制在pA-nA/m²范围。在类风暴强迫下,冠部峰值电场达到100-1000 kV/m,接近或超过经验电晕起始阈值,同时只要存在高耸桅杆,对顶角或收集器几何形状的不确定性基本不敏感。这些结果使贝托隆关于发光“羽饰”的报告在物理上合理,但表明任何晴空农业影响都是微弱且高度局部的,现代“电栽培”主张需要超出预电晕状态的仔细耦合静电和生物学研究。

英文摘要

Pierre-Nicolas Bertholon's 18th-century electrovegetometer was conceived to harness "atmospheric electricity" for plant growth, yet its physical capabilities have never been quantified within the context of today's understanding of the Earth's atmospheric electric system. This study addresses the lack of quantitative assessment of such historical "electroculture" device and its plausible influence on the near-canopy electrical environment. It aims to reinterpret Bertholon's apparatus using contemporary atmospheric electrodynamics, asking under which realistic fair-weather and storm-like conditions a purely passive collector-distributor could generate fields and ion fluxes of physical significance. A two-dimensional, quasi-steady ohmic model has been developed in which the atmosphere is a resistive column carrying the global conduction current, the metal structure is a floating conductor supported by leaky wooden insulators and space-charge and corona are excluded so that all results describe pre-onset upper bounds. The simulations show that in fair weather the single upper point and the lower multi-point crown of the electrovegetometer enhance the background field by two to three orders of magnitude, yet only within millimetric-centimetric regions around the tips and with total currents limited to the pA-nA/m^2 range. Under storm-like forcing, peak fields at the crown reach 100-1000 kV/m, approaching or exceeding empirical corona-onset thresholds, while remaining largely insensitive to uncertainties in apex angle or collector geometry as long as an elevated mast is present. These results make Bertholon's reports of luminous "aigrettes" physically plausible, but suggest that any fair-weather agronomic impact was subtle and highly localized and that modern "electroculture" claims require careful, coupled electrostatic and biological studies beyond the pre-corona regime.

2606.10429 2026-06-10 physics.hist-ph 新提交

From Electroculture to Plasma Agriculture: A Three-Century Arc Bridging Bertholon's Legacy with Contemporary Farming Advances

从电培养到等离子农业:跨越三个世纪的弧线——连接贝托隆遗产与当代农业进步

Thierry Dufour

AI总结 本文追溯了电在农业中的历史轨迹,从古代观察到冷等离子体的出现,强调贝托隆18世纪利用电植物计引导大气电刺激作物的先驱工作,并展示等离子农业如何将启蒙直觉转化为可持续农业的可重复实验框架。

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Journal ref
Compte-Rendus Mecanique de l'Academie des Sciences, Volume 354 (2026), pp. 89-116
AI中文摘要

本文综述追溯了电在农业中的历史轨迹,从对电现象的最早观察到冷等离子体的出现。回顾古代及启蒙时代,重点介绍了阿贝·贝托隆在18世纪利用电植物计等装置引导大气电刺激作物的努力。尽管这些早期电培养实验既未依赖定量剂量学,也未采用严格方法,但它们预示了将电能可控转移至植物的想法。随后,综述考察了19和20世纪流电学、电化学及气体放电物理学的历史发展,这些共同为当代冷等离子体技术奠定了基础。21世纪,等离子农业已成为一种整合电、化学、辐射、热及流体力学效应的跨学科方法。应用包括种子处理(预处理、引发)、刺激植物生长、土壤和水处理以及农产品净化。因此,本文重新评估了阿贝·贝托隆作为方法论先驱的贡献,并展示了他关于“赋予生机的电”的直觉如何与现代冷等离子体科学产生共鸣。最后,本文论证等离子农业能够将启蒙时代的直觉转化为可持续农业和食品安全的可重复实验框架。

英文摘要

This review traces the historical trajectory of electricity in agriculture, from the earliest observations of electrical phenomena to the emergence of cold plasmas. Looking back to Antiquity and then to the Enlightenment, it underlines Abbé Bertholon's 18th-century efforts to channel atmospheric electricity to stimulate crops, using devices such as the electro-végétomètre. Although these early electroculture experiments relied on neither quantitative dosimetry nor rigorous methodology, they foreshadowed the idea of a controlled transfer of electrical energy to plants. Then the review examines the historical development of galvanism, electrochemistry, and the physics of gaseous discharges throughout the 19th and 20th centuries, which collectively laid the foundations for contemporary cold-plasma technologies. In the 21st century, plasma agriculture has emerged as an interdisciplinary approach integrating electrical, chemical, radiative, thermal, and fluid-mechanical effects. Applications include seed treatment (preconditioning, seed priming), stimulation of plant growth, soil and water treatment, and decontamination of agri-food products. The review thus reassesses Abbé Bertholon's contributions as those of a methodological precursor and shows how his intuition of a "vivifying electricity" resonates with modern cold-plasma science. Finally, it argues that plasma agriculture can transform an Enlightenment intuition into a reproducible experimental framework for sustainable agriculture and food safety.

2606.10390 2026-06-10 physics.med-ph 新提交

Foveated-Imaging Geometry CT Architecture and Seeded Diffusion Model Enabling Global Super-Resolution Reconstruction

中心凹成像几何CT架构与种子扩散模型实现全局超分辨率重建

Wenxin Mo, Yingxian Xia, Yongle Yan, Hao Zhou, Li Zhang, Hewei Gao

AI总结 提出中心凹成像几何CT架构,集成局部高分辨率数据到低分辨率主导的采集方案,并开发扩散概率超分辨率重建框架,实现全场高分辨率CT图像重建。

Comments 24pages,10figures

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AI中文摘要

对于X射线计算机断层扫描(CT),较小的探测器像素尺寸通常导致更高的扫描仪空间分辨率,但不可避免地增加系统成本以及采集和处理中的数据开销。为了以更资源高效的方式实现高分辨率(HR)CT成像,我们提出了一种中心凹成像几何CT(FIGCT)架构,该架构将局部HR数据集成到以低分辨率(LR)测量为主的采集方案中。我们进一步开发了扩散概率FIGCT超分辨率重建(DPFSR)框架,以在整个视场(FOV)上生成全局HR CT图像。首先建立了FIGCT的概念,并根据HR数据的排列表征其典型配置。引入了两个关键指标,即HR数据分数(HDF)和LR与HR探测器像素尺寸比(LHR),以描述FIGCT几何。所提出的DPFSR在反向扩散过程中将局部HR信息纳入投影域和图像域的中间干净图像估计中。这一额外步骤不仅引导从LR数据生成HR图像,还提高了干净图像估计与原始测量数据之间的数据一致性。在FIGCT上的初步数值模拟结果表明,所提出的架构在对应于HR数据的感兴趣区域(ROI)内提供了高精度CT图像,而在ROI外空间分辨率迅速恶化。通过DPFSR,在AAPM Grand Challenge数据集和猪肺CT数据上实现了全局HR重建,在感知图像块相似度(LPIPS)、PSNR和SSIM方面优于现有SR方法。

英文摘要

For X-ray computed tomography (CT), a smaller detector pixel size generally leads to higher scanner spatial resolution, but inevitably increases system cost as well as data overhead in acquisition and processing. To achieve high-resolution (HR) CT imaging in a more resource-efficient manner, we propose a Foveated-Imaging Geometry CT (FIGCT) architecture, which integrates local HR data into an acquisition scheme dominated by low-resolution (LR) measurements. We further develop a Diffusion Probabilistic FIGCT Super-Resolution Reconstruction (DPFSR) framework to generate global HR CT images over the full field of view (FOV). The concept of FIGCT is first established, and its typical configurations are characterized according to the arrangement of HR data. Two key indices, namely the HR data fraction (HDF) and the LR-to-HR detector pixel size ratio (LHR), are introduced to describe the FIGCT geometry. The proposed DPFSR incorporates local HR information into intermediate clean-image estimates in both the projection and image domains during the reverse diffusion process. This additional step not only guides HR image generation from LR data, but also improves data consistency between the clean-image estimates and the originally measured data. Preliminary numerical simulation results on FIGCT show that the proposed architecture provides high-precision CT images within the region of interest (ROI) corresponding to the HR data, while the spatial resolution deteriorates rapidly outside the ROI. With DPFSR, global HR reconstruction is achieved on the AAPM Grand Challenge dataset and swine lung CT data, outperforming existing SR methods in terms of Learned Perceptual Image Patch Similarity (LPIPS), PSNR, and SSIM.

2606.10386 2026-06-10 physics.flu-dyn 新提交

Baroclinic wave dynamics in the Ekman-free rotating rectangular annulus with localized forced plume

具有局部强迫羽流的无埃克曼旋转矩形环状区域中的斜压波动力学

Shivam Swarnakar, Ayan Kumar Banerjee, Sridhar Balasubramanian, Amitabh Bhattacharya

AI总结 通过数值模拟研究旋转矩形环状区域中由均匀冷却内壁和局部加热羽流驱动的斜压波动力学,发现波模随Rossby数变化,羽流形态由Richardson数控制,并建立了(Ri0, Ro)平面上的状态图。

Comments The draft is submitted to Physics of Fluids

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AI中文摘要

我们报告了旋转矩形环状区域的数值模拟,该区域隔离了圆柱斜压环状区域的无埃克曼主体,受到由均匀冷却内壁和位于外底部的局部强迫加热羽流施加的双向温度梯度。采用有限体积OpenFOAM求解器,组合源Richardson数 $Ri_0 = 99, 4, 1$ 和Rossby数 $Ro = 0.3, 0.1, 0.07$。控制方程的无量纲缩放确定地转-静力平衡为主导阶体态,这一结果由 $x$ 和 $z$ 方向动量收支后验证实。$Ro=0.3$ 时的 $m=2$ 模斜压波随着 $Ro$ 减小转变为 $m=3$,与Eady变形半径 $L_\rho = NH/f$ 的收缩一致;复经验正交函数(CEOF)分析表征了波态,并在 $Ri_0 = 99,~Ro = 0.1$ 处检测到Hopf分岔的振荡状态。通过Morton长度尺度和源通量平衡参数分类的羽流形态,从 $Ri_0 = 99$ 时的弱横向扫掠结构转变为 $Ri_0 \leq 4$ 时穿越整个斜压深度的持续柱状羽流。羽流卷吸系数 $\Gamma(z)$ 在低和高 $Ri_0$ 时表现出相反的旋转敏感性,我们通过局部羽流Rossby数 $Ro_p = w/(2\Omega b)$ 进行组织。混合长度论证预测体湍流热通量 $\overline{u'T'} \propto Ri_0^{-1/2}$,预期从 $Ri_0 = 99$ 到 $Ri_0 = 1$ 增强一个数量级,与模拟结果一致。$(Ri_0, Ro)$ 平面上的状态图显示,在探索范围内,羽流态和波选择问题近似可分离:$Ri_0$ 决定羽流态,而 $Ro$ 选择主导斜压波模。

英文摘要

We report numerical simulations of a rotating rectangular annulus that isolates the Ekman-free bulk of the cylindrical baroclinic annulus, subjected to bi-directional temperature gradients imposed by a uniformly cooled inner wall and a localized forced heated plume at the outer bottom. The finite-volume OpenFOAM solver is employed across combinations of source Richardson number $Ri_0 = 99, 4, 1$ and Rossby number $Ro = 0.3, 0.1, 0.07$. A non-dimensional scaling of the governing equations identifies geostrophic-hydrostatic balance as the leading-order bulk state, a result confirmed a posteriori by the $x$ and $z-$momentum budgets. Baroclinic waves of mode $m=2$ at $Ro=0.3$ transition to $m=3$ as $Ro$ decreases, consistent with the contraction of the Eady deformation radius $L_ρ= NH/f$; Complex Empirical Orthogonal Function (CEOF) analysis characterizes the wave regime and detects a Hopf-bifurcated vacillating state at $Ri_0 = 99,~Ro = 0.1$. The plume morphology, classified through the Morton length scale and source flux-balance parameter, transitions from weak, laterally-swept structures at $Ri_0 = 99$ to sustained columnar plumes traversing the full baroclinic depth at $Ri_0 \leq 4$. The plume entrainment coefficient $Γ(z)$ shows opposite rotational sensitivities at low and high $Ri_0$, which we organize through a local plume Rossby number $Ro_p = w/(2Ωb)$. A mixing-length argument predicts a bulk turbulent heat flux $\overline{u'T'} \propto Ri_0^{-1/2}$, anticipating an order-of-magnitude enhancement from $Ri_0 = 99$ to $Ri_0 = 1$, in agreement with the simulations. A regime map in the $(Ri_0, Ro)$ plane reveals that, within the explored range, the plume-regime and wave-selection problems are approximately separable: $Ri_0$ sets the plume regime while $Ro$ selects the dominant baroclinic wave mode.

2606.10370 2026-06-10 physics.comp-ph 新提交

Flow-based generative models for amortized Bayesian inference in regression and inverse PDE problems

基于流的生成模型用于回归和反问题PDE中的摊销贝叶斯推断

Shaoqian Zhou, Ling Guo, Xuhui Meng

AI总结 提出Flow-ABI框架,通过流匹配学习函数先验和条件后验采样器,实现回归和反问题PDE中的摊销贝叶斯推断,支持变观测集和快速后验采样。

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AI中文摘要

贝叶斯推断为科学机器学习中的不确定性量化提供了原则性框架。然而,传统的贝叶斯方法通常需要为每个观测集解决一个新的推断问题,导致巨大的计算成本,阻碍了在线监控和数字孪生等实时应用。此外,在具有变化观测集的无限维函数空间上进行推断,对现有的摊销推断方法构成了重大挑战。在这项工作中,我们提出了Flow-ABI,一个基于流的生成框架,用于回归和反问题偏微分方程(PDE)中的摊销贝叶斯推断。它由两个部分组成:(i) 一个函数先验模型,通过流匹配从历史数据和物理知识中学习表达性先验,以及(ii) 一个条件于观测集的函数后验采样器,将观测集映射到函数后验分布。学习到的后验模型自然地适应变化、排列不变的观测集,并泛化到不同的观测离散化。一旦训练完成,Flow-ABI能够在无需重新训练或迭代优化的情况下,对未见过的观测进行近乎实时的后验采样。所提出的方法可以无缝集成到广泛的科学机器学习框架中,包括物理信息神经网络和神经算子,用于不确定性感知的反问题PDE建模。实验表明,Flow-ABI准确捕捉了高斯和非高斯后验分布,同时相对于黄金标准的贝叶斯推断方法——哈密顿蒙特卡洛,实现了超过两个数量级的加速。这些结果表明,Flow-ABI是科学机器学习中不确定性量化的一个有效、可扩展且计算高效的框架。

英文摘要

Bayesian inference provides a principled framework for uncertainty quantification in scientific machine learning. However, conventional Bayesian approaches usually require solving a new inference problem for each observation set, causing substantial computational costs that hinder real-time applications like online monitoring and digital twins. Furthermore, inferring over infinite-dimensional function spaces with varying observation sets poses major challenges for existing amortized inference methods. In this work, we propose Flow-ABI, a flow-based generative framework for amortized Bayesian inference in regression and inverse partial differential equation (PDE) problems. It consists of two components: (i) a functional prior model that learns expressive priors from historical data and physical knowledge through flow matching, and (ii) a set-conditioned functional posterior sampler mapping observation sets to functional posterior distributions. The learned posterior model naturally accommodates varying, permutation-invariant observation sets, and generalizes across different observation discretizations. Once trained, Flow-ABI enables near-real-time posterior sampling for previously unseen observations without retraining or iterative optimization. The proposed methodology can be seamlessly integrated with a wide class of scientific machine learning frameworks, including physics-informed neural networks and neural operators, for uncertainty-aware inverse PDE modeling. Experiments demonstrate that Flow-ABI accurately captures both Gaussian and non-Gaussian posterior distributions while achieving over two-order-of-magnitude speedups relative to the gold-standard Bayesian inference method, Hamiltonian Monte Carlo. These results show Flow-ABI is an effective, scalable, and computationally efficient framework for uncertainty quantification in scientific machine learning.

2606.10335 2026-06-10 physics.comp-ph cs.NA math.NA physics.flu-dyn 新提交

A Physics-Informed B-Spline Framework for Continuous Approximation of Flow Data

基于物理信息的B样条框架用于流数据的连续逼近

Junoh Jung, David Lenz, Emil Constantinescu, Tom Peterka

AI总结 提出物理信息B样条框架(PI-MFA),通过优化平衡数据保真度与PDE残差来嵌入物理约束,实现流数据的连续逼近,在保持样条紧凑性和可微性的同时提高物理一致性。

Comments 59 pages, 21 figures, 11 tables

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AI中文摘要

流数据的连续逼近对于下游分析、微分和可视化很有用,但纯数据驱动的重构通常不保留控制物理。当输入数据物理不一致时,无论是由于低保真离散化还是未建模的差异,这一限制变得尤为重要。在这种情况下,重构场可能表现出不准确的PDE残差、违反守恒定律或不可靠的导出量。为了解决这个问题,我们提出了一种物理信息B样条框架,将物理约束直接嵌入重构过程。该方法使用张量积B样条构造离散场的紧凑、连续可微表示,并通过求解优化问题确定样条控制点,该优化问题平衡数据保真度与控制PDE的残差以及初始和边界条件。利用B样条基的精确解析导数,可以在不存储全分辨率场的情况下高效准确地评估物理残差。我们将这种方法称为物理信息多元函数逼近(PI-MFA)。在1D对流扩散、2D耦合Burgers和2D不可压缩Navier-Stokes方程上的数值研究表明,PI-MFA减少了PDE残差并改善了全局守恒律一致性。与标准和正则化MFA相比,PI-MFA产生更物理逼真的重构,并且对于物理不一致的数据,逼近误差更低,同时在计算上优于测试的物理信息神经网络。总体而言,PI-MFA保留了经典样条空间的紧凑性、局部支持和精确可微性,同时为科学分析和可视化生成可靠的连续流场。

英文摘要

Continuous approximations of flow data are useful for downstream analysis, differentiation, and visualization, but purely data-driven reconstructions do not, in general, preserve the governing physics. This limitation becomes particularly important when input data are physically inconsistent, whether due to low-fidelity discretizations or unmodeled discrepancies. In such cases, reconstructed fields may exhibit inaccurate PDE residuals, violated balance laws, or unreliable derived quantities. To address this, we propose a physics-informed B-spline framework that embeds physical constraints directly into the reconstruction process. The method constructs compact, continuously differentiable representations of discrete fields using tensor-product B-splines and determines spline control points by solving an optimization problem balancing data fidelity with residuals of the governing PDEs, alongside initial and boundary conditions. Leveraging exact analytical derivatives of the B-spline basis enables efficient and accurate evaluation of physical residuals without storing full-resolution fields. We refer to this approach as physics-informed multivariate functional approximation (PI-MFA). Numerical studies on the 1D convection-diffusion, 2D coupled Burgers, and 2D incompressible Navier-Stokes equations show PI-MFA reduces PDE residuals and improves global balance-law consistency. Compared with standard and regularized MFA, PI-MFA produces more physically faithful reconstructions and, for physically inconsistent data, lower approximation errors, while offering computational advantages over tested physics-informed neural networks. Overall, PI-MFA preserves the compactness, local support, and exact differentiability of classical spline spaces while producing reliable continuous flow fields for scientific analysis and visualization.

2606.10310 2026-06-10 physics.plasm-ph 新提交

DKEKAN: A single-parameterized KAN surrogate for Drift Kinetic Equation Toward Fast Neoclassical Toroidal Viscosity Torque Modeling in Tokamaks

DKEKAN:面向托卡马克中快速新经典环向黏滞力矩建模的漂移动力学方程单参数化KAN代理模型

Jinpeng Huang, Xingting Yan, Mingyu Zhang, Nana Bao, Zixuan Song, Yuetao Meng, Weiyong Zhou, Youwen Sun

AI总结 针对托卡马克中新经典环向黏滞(NTV)力矩计算的高计算成本问题,提出基于单参数化KAN网络的代理模型DKEKAN,通过求解漂移动力学方程实现快速NTV建模,在EAST等离子体参数下将独立求解时间从35.85秒降至3.74秒,加速约9.6倍。

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AI中文摘要

新经典环向黏滞(NTV)力矩是托卡马克中环向旋转的关键驱动力,深刻影响等离子体稳定性与性能。因此,将NTV效应纳入旨在自洽统一多种物理过程的现代集成建模框架至关重要。然而,NTV建模的高计算成本阻碍了其在框架中的自洽集成。这一瓶颈源于NTV计算需要在高维相空间中求解其控制方程——漂移动力学方程(DKE)。为解决此问题,本研究开发了DKEKAN,一种用于求解DKE的单参数化Kolmogorov-Arnold网络(SKAN)代理模型,以实现托卡马克中的快速NTV建模。研究过程包括以下步骤:首先,基于实验先进超导托卡马克(EAST)等离子体参数下的第一性原理模拟,生成一个将DKE方程参数映射到解的大型数据集;其次,基于SKAN框架开发求解DKE的代理模型,该模型还采用了模块化专家网络设计;最后,将DKEKAN代理模型与NTV建模框架集成,实现快速NTV计算。凭借其物理分组专家层和SKAN主干,DKEKAN在整体预测精度上优于测试的MLP、KAN和神经算子基线,同时将独立DKE求解时间从35.85秒降至3.74秒,加速约9.6倍,并将耦合NTVTOK总运行时间从38.24秒降至5.58秒,整体加速约6.9倍。本工作有效克服了NTV模拟中的计算瓶颈,从而支持进一步纳入NTV效应的集成建模。

英文摘要

The neoclassical toroidal viscosity (NTV) torque is a critical driver of toroidal rotation in tokamaks, profoundly influencing plasma stability and performance. Consequently, incorporating NTV effects is essential for modern integrated modeling frameworks that aim to self-consistently unify multiple physical processes. However, the high computational cost of NTV modeling precludes its self-consistent integration within such frameworks. This bottleneck arises because NTV calculation requires solving its governing equation--the drift kinetic equation (DKE)--in high-dimensional phase space. To address this issue, this study develops DKEKAN, a single-parameterized Kolmogorov-Arnold Network (SKAN) surrogate for solving DKE, to realize fast NTV modeling in tokamaks. The research process consists of the following steps: Firstly, a large dataset mapping DKE equation parameters to solutions is generated based on first-principle simulations under plasma parameters of the Experimental Advanced Superconducting Tokamak (EAST); Secondly, a surrogate model for solving DKE is developed based on the SKAN framework, which also incorporates a modular expert network design; Finally, the DKEKAN surrogate model is integrated with the NTV modeling framework to realize fast NTV calculation. With its physics-grouped expert layer and SKAN backbone, DKEKAN outperforms the tested MLP, KAN, and neural-operator baselines in overall prediction accuracy, while reducing the standalone DKE-solving time from 35.85s to 3.74s, corresponding to a speedup of approximately 9.6x, and reducing the total coupled NTVTOK runtime from 38.24s to 5.58s, corresponding to an overall speedup of approximately 6.9x. This work effectively overcomes the computational bottleneck in NTV simulations, thus supporting further integrated modeling that incorporates NTV effects.

2606.10272 2026-06-10 physics.atm-clus 新提交

Rainbow RABBITT as a Probe of Coherent Rabi Dynamics

彩虹RABBITT作为相干拉比动力学的探针

Vladislav V. Serov, Anatoli S. Kheifets

AI总结 利用彩虹RABBITT技术,通过分析单边带内的相位色散,揭示了共振驱动原子中隐藏的相干拉比动力学,并建立了新的干涉测量观测量。

Comments 8 pages, 4 figures

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AI中文摘要

与共振修饰原子相互作用的阿秒脉冲串会产生显著的单边带内相位结构,这在传统的谱积分RABBITT测量中隐藏不见。利用锂原子在共振$2s\ o2p$跃迁附近的\textit{从头算}含时薛定谔方程计算,我们展示了单个边带内提取的相位在其谱宽上可以变化近$\pi$。由此产生的单边带内相位色散表现出对红外失谐、脉冲持续时间、强度和边带阶数的特征依赖性。最引人注目的是,精确共振拉比振荡使单边带内相位色散变平,而小的失谐尽管导致较弱的布居转移,却产生显著的相位调制。这种反直觉的行为表明,彩虹RABBITT探测的是由拉比修饰波包积累的动力学相位,而不是参与态的瞬时布居。一个简单的解析模型捕捉了数值计算的主要特征,并为单边带内相位结构的出现提供了物理洞察。这些结果确立了单边带内相位色散作为映射相干拉比动力学的一种新的干涉测量观测量。

英文摘要

Attosecond pulse trains interacting with a resonantly dressed atom generate a pronounced intra-sideband phase structure that remains hidden in conventional spectrally integrated RABBITT measurements. Using \textit{ab initio} time-dependent Schrödinger equation calculations for lithium near the resonant $2s\to2p$ transition, we show that the phase extracted within a single sideband can vary by nearly $π$ across its spectral width. The resulting intra-sideband phase dispersion exhibits a characteristic dependence on the IR detuning, pulse duration, intensity, and sideband order. Most strikingly, exact resonant Rabi flopping flattens the intra-sideband phase dispersion, whereas a small detuning generates a pronounced phase modulation despite weaker population transfer. This counterintuitive behavior demonstrates that rainbow RABBITT probes the dynamical phase accumulated by a Rabi-dressed wave packet rather than the instantaneous populations of the participating states. A simple analytical model captures the principal features of the numerical calculations and provides physical insight into the emergence of the intra-sideband phase structure. These results establish intra-sideband phase dispersion as a new interferometric observable for mapping coherent Rabi dynamics.

2606.10269 2026-06-10 physics.app-ph 新提交

Fast-Neutron Irradiation Effect in Heteroepitaxial $β$-Ga$_2$O$_3$ Schottky Diodes Fabricated on Low-Cost Sapphire Substrates

低成本蓝宝石衬底上异质外延$\beta$-Ga$_2$O$_3$肖特基二极管的快中子辐照效应

Saleh Ahmed Khan, Ahmed Ibreljic, Sourav Sarker, Stephen Margiotta, Anhar Bhuiyan

AI总结 研究Ni/$\beta$-Ga$_2$O$_3$肖特基二极管在快中子辐照下的电学特性变化,发现载流子去除率约105 cm$^{-1}$,击穿电压从101 V增至135 V,表明中子诱导施主补偿主导器件退化。

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AI中文摘要

本文研究了在c面蓝宝石上制备的Ni/$\beta$-Ga$_2$O$_3$肖特基势垒二极管在快中子辐照至通量$1\times10^{15}$ n$\cdot$cm$^{-2}$下的响应。LPCVD生长的异质外延结构包括非故意掺杂缓冲层、n$^{+}$接触层和n型漂移层,通过无等离子体Ga辅助LPCVD刻蚀实现台面隔离。辐照前,器件开启电压为1.20 V,比导通电阻为8.43 m$\Omega\cdot$cm$^2$,理想因子为1.32,肖特基势垒高度为1.29 eV。辐照后,器件仍可工作,但正向电流减小,开启电压增至2.40 V,势垒高度增至1.34 eV。电容-电压测量显示净施主浓度降低约50%,对应载流子去除率约105 cm$^{-1}$。25至250 $^\circ$C的温度相关测量证实热电子发射仍是主要输运机制,并显示辐照后反向漏电流显著抑制。击穿电压从101 V增至135 V,与中子诱导施主补偿一致。TCAD模拟显示辐照后电场分布更均匀,肖特基边缘电场集中减弱。这些结果揭示了异质外延$\beta$-Ga$_2$O$_3$中中子诱导施主补偿的机理,并证明了在蓝宝石上LPCVD生长的$\beta$-Ga$_2$O$_3$肖特基二极管在空间和核电子学相关的高通量中子环境下保持稳定运行的能力。

英文摘要

In this work, we investigate the response of Ni/$β$-Ga$_2$O$_3$ Schottky barrier diodes fabricated on c-plane sapphire to fast-neutron irradiation up to a fluence of $1\times10^{15}$ n$\cdot$cm$^{-2}$. The LPCVD-grown heteroepitaxial structure consists of an unintentionally doped buffer, an n$^{+}$ contact layer, and an n-type drift layer, with mesa isolation realized by plasma-free Ga-assisted LPCVD etching. Prior to irradiation, the devices exhibit a turn-on voltage of 1.20 V, specific on-resistance of 8.43 m$Ω\cdot$cm$^2$, ideality factor of 1.32, and Schottky barrier height of 1.29 eV. Following irradiation, the devices remain operational, although the forward current decreases, the turn-on voltage increases to 2.40 V, and the barrier height increases to 1.34 eV. Capacitance-voltage measurements reveal a $\sim$50% reduction in net donor concentration, corresponding to a carrier-removal rate of $\sim$105 cm$^{-1}$. Temperature-dependent measurements from 25 to 250 $^\circ$C confirm that thermionic emission remains the dominant transport mechanism and show significant suppression of reverse leakage current after irradiation. The breakdown voltage increases from 101 to 135 V, consistent with neutron-induced donor compensation. TCAD simulations show a more uniform electric-field distribution and reduced field crowding at the Schottky edge after irradiation. These results provide insight into neutron-induced donor compensation in heteroepitaxial $β$-Ga$_2$O$_3$ and demonstrate the ability of LPCVD-grown $β$-Ga$_2$O$_3$ Schottky diodes on sapphire to maintain stable operation under high-fluence neutron environments relevant to space and nuclear electronics.

2606.10268 2026-06-10 physics.flu-dyn 新提交

Rotation-to-translation conversion by geometric asymmetry in viscoelastic fluids

粘弹性流体中几何不对称导致的旋转-平动转换

Takuya Kobayashi, Hiroki Kitano, Ryoichi Yamamoto

AI总结 本文发现粘弹性流体中,非手性前后不对称旋转体通过法向应力驱动的二次流产生净平动,并建立了普适标度律V~Wi·S,为旋转诱导推进提供了最小几何原理。

Comments 6 pages, 4 figures

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AI中文摘要

在牛顿流体中的微观运动受到运动学可逆性的约束。这里我们展示粘弹性提供了一条不同的路径:一个非手性前后不对称的物体在粘弹性流体中旋转,通过法向应力驱动的二次流产生净平动。直接数值模拟结合标度分析揭示了普适标度律,$V\sim {\rm Wi}\cdot S$,其中$\rm Wi$是魏森贝格数,$S$是轴向体积分布的偏度。这一结果确定了粘弹性流体中旋转诱导推进的最小几何原理,并提出了通过推进速度测量进行主动微流变学的途径。

英文摘要

Microscale locomotion in Newtonian fluids is constrained by kinematic reversibility. Here we show that viscoelasticity provides a distinct route: an achiral fore-aft asymmetric body rotating in a viscoelastic fluid generates net translation through normal-stress-driven secondary flows. Direct numerical simulations combined with scaling analysis reveal the universal scaling law, $V\sim {\rm Wi}\cdot S$, where $\rm Wi$ is the Weissenberg number and $S$ is the skewness of the axial volume distribution. This result identifies a minimal geometric principle for rotation-induced propulsion in viscoelastic fluids, and suggests a route for active microrheology via propulsion-speed measurements.

2606.10253 2026-06-10 physics.optics physics.app-ph 新提交

Multi-channel Optical Vision Model

多通道光学视觉模型

Ali Momeni, Guillaume Noetinger, Tim Tuuva, Romain Fleury

AI总结 本文利用光学神经网络中的空间复用,将通道作为可训练表示坐标,通过在线物理前向/代理反向训练,在图像分类和回归任务中实现多通道功能,并构建了混合光电视觉语言模型。

Comments 24 pages, 4 figures

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AI中文摘要

空间复用是光学的天然优势之一,然而在光学神经网络中,它通常主要被用作并行吞吐量。这里,我们展示了光学神经网络中的空间复用不仅可以用于并行处理多个输入,还可以用于定义模型的可训练表示坐标。在三种实现的场景中:并行输入处理、类别码读出和通道混合特征交互,空间通道分别充当独立学习者、结构化码维度和交互特征组。可编程自由空间光学处理器通过在线物理前向/代理反向方案进行训练,其中测量的光学输出定义前向传播,而可微代理估计梯度并在训练过程中根据新获取的光学数据不断微调。我们在使用超过一百万个可训练光学相位参数的多层架构中,在图像分类和回归任务中演示了这些通道角色。我们进一步实现了一个混合光电视觉语言模型,其中光学神经网络为数字变换器解码器提供视觉令牌,用于受控图像描述任务。这些结果确立了空间复用光学通道作为混合光学视觉模型的可编程特征和读出空间。

英文摘要

Spatial multiplexing is one of the natural strengths of optics, yet in optical neural networks, it is often used mainly as parallel throughput. Here, we show that spatial multiplexing in an optical neural network can be used not only to process multiple inputs in parallel, but also to define a trainable representational coordinate of the model. In three implemented scenarios, parallel-input processing, class-code readout and channel-mixed feature interaction, spatial channels act as independent learners, structured code dimensions, and interacting feature groups. The programmable free-space optical processor is trained through an online physical-forward/surrogate-backward scheme, where measured optical outputs define the forward pass while a differentiable surrogate estimates gradients and is continually fine-tuned during training from newly acquired optical data. We demonstrate these channel roles in image classification and regression tasks using multi-layer architectures with more than one million trainable optical phase parameters. We further implement a hybrid optical-electronic vision-language model, in which the optical neural network provides visual tokens to a digital transformer decoder for controlled image-captioning tasks. These results establish spatially multiplexed optical channels as a programmable feature and readout space for hybrid optical vision models.

2606.10236 2026-06-10 physics.app-ph 新提交

Limits of Trap-assisted Photomultiplication Gain

陷阱辅助光电倍增增益的极限

Ardalan Armin

AI总结 本文通过最小分析框架研究陷阱辅助电流注入光电二极管的增益,发现增益本质自限,且增益引入非负波动惩罚,局部探测率存在有限最优值,无法超越本征热力学极限。

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AI中文摘要

基于陷阱辅助电流注入的光电二极管可以表现出内部光电倍增,其表观量子效率远超1,这引发了一个问题:这种增益是否从根本上提高了探测器的灵敏度。我们采用一个基于单个增益活性陷阱态的最小分析框架,该陷阱态将光生载流子与接触注入耦合。增益本质上是自限的:放大电流的注入过程同时加速了增益态的弛豫,产生固有的非线性、依赖于工作点的响应。这种非线性的形式并非普适——一旦陷阱能级推广到能量分布并允许双分子复合,同一机制会产生超线性、线性或强亚线性响应。因此,单个弦增益不是有意义的器件描述符,文献中的弦增益比较混淆了不同工作区的器件。将陷阱占据和注入视为耦合随机过程,我们证明内部增益从维持增益态的耗散动力学中引入了一个严格非负的波动惩罚。局部小信号探测率存在有限最优值,但无法超过底层单位增益光电二极管的本征热力学极限。因此,增益等价于驱动随机放大:它可以抑制下游读出噪声,但无法降低由初级光电探测过程设定的基本噪声底限。

英文摘要

Photodiodes based on trap-assisted current injection can exhibit internal photomultiplication with apparent quantum efficiencies far exceeding unity, raising the question of whether such gain fundamentally enhances detector sensitivity. We employ a minimal analytical framework based on a single gain-active trapped state coupling photogenerated carriers to contact injection. The gain is intrinsically self-limiting: the injection process that amplifies the current simultaneously accelerates relaxation of the gain-enabling state, producing an inherently nonlinear, operating-point-dependent response. The form of this nonlinearity is not universal -- once the trap level is generalized to an energetic distribution and recombination is allowed to be bimolecular, the same mechanism yields superlinear, linear, or strongly sublinear responses. A single chord gain is therefore not a meaningful device descriptor, and chord-gain comparisons across the literature conflate devices in different regimes. Treating trap occupancy and injection as coupled stochastic processes, we show that internal gain introduces a strictly non-negative fluctuation penalty from the dissipative dynamics that sustain the gain state. A local, small-signal detectivity exhibits a finite optimum yet cannot exceed the intrinsic thermodynamic limit of the underlying unity-gain photodiode. Gain is thus equivalent to driven stochastic amplification: it can suppress downstream readout noise, but cannot reduce the fundamental noise floor set by the primary photodetection process.

2606.10232 2026-06-10 physics.ins-det 新提交

Electric Field Optimization of High-Voltage Vacuum Feedthroughs

高压真空馈通件的电场优化

Lin Si, Evan Angelico, Giorgio Gratta

AI总结 针对高压真空馈通件真空侧电场过大问题,通过解析计算和有限元分析优化中心导体直径,提出不改动放气性能的简单改造方案。

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AI中文摘要

我们报告了高压真空馈通件的优化,旨在最小化器件真空侧的电场。我们发现商用馈通件的中心导体直径通常过小,导致不必要的强电场。我们通过解析计算和有限元分析研究了该问题,并为所研究的商用馈通件提出了一种简单的优化改造方案,同时不损害其放气性能。这项工作对于馈通件的“真空侧”实际上填充了可能不具备真空电压刚度的介电质的应用场景非常重要。

英文摘要

We report on the optimization of high voltage vacuum feedthroughs meant to minimize the electric field on the vacuum side of the device. We find that commercial feedthroughs generally have center conductor diameters which are too small, resulting in unnecessarily large fields. We study the problem with analytical calculations and finite element analysis, and present a simple, optimized retrofit for the commercial feedthroughs studied here, without compromising their outgassing properties. This work is important for applications whereby the ``vacuum side'' of the feedthrough is, in fact, filled with a dielectric which may not have the voltage rigidity of vacuum.

2606.10215 2026-06-10 physics.space-ph physics.plasm-ph 新提交

LEAP: A Rapid Neural Surrogate of Multi-Fluid MHD at Europa

LEAP: 欧罗巴多流体磁流体动力学的快速神经替代模型

Sachin Alexander Reddy, Abigail R. Azari, Corey J. Cochrane, Xianzhe Jia, Tom A. Nordheim, Lukas Mandrake, Steven D. Vance, Camilla Harris, Ioana Ciucǎ

AI总结 针对欧罗巴地下海洋探测中MHD模型计算成本高的问题,提出基于Transformer的替代模型LEAP,实现毫秒级预测磁场扰动,速度提升约40000倍,精度与MHD相当。

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AI中文摘要

表征欧罗巴的地下海洋是欧罗巴快帆号和JUICE任务在寻找地外生命方面的关键目标。尽管海洋的感应磁场为宜居性提供了关键约束,但木星等离子体与欧罗巴相互作用产生的扰动使解释变得复杂。表征这些效应所需的基于物理的模型(例如磁流体动力学,MHD)在物理上全面,但计算成本过高。为了解决这个问题,我们引入了学习欧罗巴大气和等离子体(LEAP),这是一个基于Transformer的替代模型,训练于最先进的多流体MHD代码的输出,用于预测航天器轨迹上的磁场扰动。LEAP在笔记本电脑上毫秒级评估,而MHD在高性能计算机上需要12小时(约40000倍加速)。该模型在测试集上的误差为-/+ 2.6 nT,对于伽利略号E4和E14飞越欧罗巴的任务,其精度与父MHD模型相当。其增强的速度使得大规模参数调查和等离子体条件的概率估计成为可能,为加速等离子体相互作用建模建立了新框架。LEAP还可以在学习的同时为未来的MHD模拟提供信息。超越欧罗巴,该框架可以扩展到规划未来任务或其他高优先级天体,包括天王星和海王星。

英文摘要

Characterizing Europa's subsurface ocean is a key objective of the Europa Clipper and JUICE missions in the search for life beyond Earth. Although the ocean's induced magnetic field provides key constraints on habitability, interpretation is complicated by perturbations arising from Jupiter's plasma interaction with Europa. Physics-based models (e.g. magnetohydrodynamic, MHD) required to characterize these effects are physically comprehensive, but have a prohibitive computational cost. To address this, we introduce Learning Europa's Atmosphere and Plasma (LEAP), a transformer-based surrogate trained on outputs from a state-of-the-art multi-fluid MHD code to predict magnetic field perturbations along spacecraft trajectories. LEAP evaluates in milliseconds on a laptop, whereas MHD takes 12 hrs on a high-performance computer (~40,000x speed-up). The model has test set errors of -/+ 2.6 nT, and for the Galileo E4 and E14 flybys of Europa it matches the parent MHD model in accuracy. Its enhanced speed enables large-scale parameter surveys and probabilistic estimations of plasma conditions, establishing a new framework for accelerated plasma interaction modeling. LEAP can also inform future MHD simulations while learning from them. Beyond Europa, this framework could be expanded to planning future missions or to other high-priority bodies, including Uranus and Neptune.

2606.10188 2026-06-10 physics.flu-dyn 新提交

Effect of a magnetostatic field on laminar premixed hydrogen-air flames

静磁场对层流预混氢-空气火焰的影响

Tristan Lapaire, Sofiane Al Kassar, Antonio Attili, Andrea Giusti

AI总结 通过直接数值模拟研究磁场对预混氢-空气火焰的影响,发现磁场梯度可降低火焰消耗速度,主要归因于火焰面积减小,且低压下效果显著,高压下可忽略。

Comments This full paper was first submitted in March 2026 for review in Proc. Combust. Inst

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AI中文摘要

磁场已显示出影响火焰特性的潜力;然而,相互作用的机制尚未完全理解。本文研究了磁场对易于发生固有不稳定性的预混氢-空气火焰的影响,重点关注磁力对火焰行为的作用。该研究采用直接数值模拟进行。研究了两种火焰条件,两者当量比均为0.5,一种反应物处于大气条件,另一种处于高压高温条件。研究了不同的磁场配置,每种配置的特征在于磁场强度平方的不同梯度,方向与来流反应物速度相反。结果表明,所研究的磁场配置可以降低火焰消耗速度,在低压情况下效果显著,而在高压下变得可忽略。磁力的影响随着磁场梯度的增加而增加,主要归因于火焰面积的减小。结果还表明,磁场对火焰反应性以及沿火焰锋面发展的小尺度细胞结构的影响可忽略。对力贡献的分析表明,火焰面积的变化是由磁力的旋转分量引起的,该分量改变了流动的涡量,使得由流体动力学不稳定性形成的指状结构趋于闭合。这些力在低压下显著,而在高压下与压力梯度相比变得可忽略。最终,这项工作的结果表明,磁力有潜力改变火焰行为,这一机制可用于火焰的主动控制。

英文摘要

Magnetic fields have shown potential to affect flame characteristics; however, the mechanisms of interaction are not fully understood. This paper investigates the effect of magnetic fields on premixed hydrogen-air flames that are prone to intrinsic instabilities, with a focus on the role of magnetic forces on the flame behaviour. The study is conducted using direct numerical simulations. Two flame conditions, both with an equivalence ratio of 0.5, are studied, one with the reactants at atmospheric conditions and the other at high pressure and high temperature. Different configurations of the magnetic field are investigated, each characterised by a different gradient of the square of the magnitude of the magnetic field, oriented in the direction opposite to the velocity of the incoming reactants. Results show that the investigated configurations of the magnetic field can reduce the flame consumption speed, an effect that is substantial in the lower pressure case, while it becomes negligible at high pressure. The effect of the magnetic forces increases with increasing gradient of the magnetic field and is mainly due to the reduction of the flame area. Results also show that the effects of magnetic fields on the reactivity of the flame and on the small cell structures developed along the flame front are negligible. Analysis of the force contributions demonstrates that the change in the flame area is caused by the rotational component of the magnetic forces, which alter the vorticity of the flow such that the finger-like structures formed by hydrodynamic instabilities tend to close. These forces are significant at low pressure, while they become negligible compared to the pressure gradient at high pressure. Ultimately, the results of this work indicate that magnetic forces have the potential to change the flame behaviour, a mechanism that could be used for active control of flames.

2606.10151 2026-06-10 physics.atom-ph 新提交

Profiling a Rydberg-Atom Electric Field Sensor for Off-Resonant Detection of Sub-100 MHz RF Signals

用于亚100 MHz射频信号离共振探测的里德伯原子电场传感器特性分析

Michael A. Viray, Abby Halasi-Kun, Baran N. Kayim, Brian C. Sawyer, Robert Wyllie, David S. La Mantia

AI总结 本文优化了里德伯原子电场传感器,使用蓝宝石蒸气室实现亚100 MHz射频信号的离共振探测,通过AC斯塔克位移检测信号,并在ISM频段测试了灵敏度、最小可探测场和动态范围,同时提出了基于Python的优化程序。

Comments 13 pages, 7 figures

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AI中文摘要

我们展示了一种优化用于探测亚100 MHz载波频率信号的里德伯原子电场传感器。该传感装置采用蓝宝石蒸气室,能够探测低于100 MHz的信号——典型的玻璃或石英蒸气室在此频率范围内对射频信号表现出强烈的屏蔽效应。施加的信号通过观察原子蒸气能级中的AC斯塔克位移来检测。作为该接收器商业实用性的测试案例,我们在工业、科学和医疗(ISM)频段的多个载波频率上进行了测试。在每个载波频率下,我们报告了灵敏度、最小可探测场和可探测电场动态范围。我们还提出了一种通过调整实验参数(如里德伯耦合激光失谐和射频本地振荡器强度)来优化离共振信号检测的常规方法。这种基于Python的优化程序可用于任何离共振载波频率,并在Github上共享,供其他人用于自己的研究。

英文摘要

We present a Rydberg-Atom electric field sensor optimized to detect signals at sub-100 MHz carrier frequencies. The sensing setup employs a sapphire vapor cell that allows for detection of signals below 100~MHz -- typical vapor cells made of glass or quartz demonstrate strong screening of radio frequency (RF) signals in this frequency regime. Applied signals are detected by observing AC Stark shifts in the atomic vapor energy levels. As a test case for the commercial utility of this receiver, we perform our tests at several carrier frequencies in the Industrial, Scientific, and Medical (ISM) band. At each carrier frequency, we report sensitivity, minimum detectable field, and detectable electric-field dynamic range. We also present a routine for optimizing off-resonant signal detection by tuning experimental parameters such as Rydberg coupler laser detuning and RF local oscillator strength. This Python-based optimization routine, which can be used at any off-resonant carrier frequency, is shared on Github for others to use in their own investigations.

2606.10121 2026-06-10 physics.ins-det 新提交

Radiation damage studies of silicon photomultipliers for the CMS MIP Timing Detector

CMS MIP定时探测器中硅光电倍增管的辐射损伤研究

Y. Musienko, A. Heering, A. Karneyeu, M. Wayne

AI总结 研究不同单元尺寸的Hamamatsu SiPM在反应堆中子辐照后的性能变化,分析击穿电压、信号幅度、暗电流和噪声等参数。

Comments Submitted to JINST, 7th International Workshop on New Photon-Detectors (PD2025)

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AI中文摘要

最近开发的15 um、20 um、25 um和30 um单元尺寸的Hamamatsu硅光电倍增管(SiPM)在JSI(卢布尔雅那)用反应堆中子辐照至2×10^14 n/cm^2(1 MeV等效)。使用脉冲光照明研究了新SiPM和辐照后SiPM的参数。展示并讨论了中子辐射对这些器件的击穿电压、信号幅度、暗电流和噪声的影响。

英文摘要

Recently developed 15 um, 20 um, 25 um and 30 um cell size Hamamatsu Silicon Photomultipliers (SiPMs) were irradiated with reactor neutrons at JSI (Ljubljana) up to 2*10^14 n/cm^2 (1 MeV equivalent). The parameters of new and irradiated SiPMs were studied using pulsed light illumination. The effects of the neutron radiation on breakdown voltage, signal amplitude, dark current and noise for these devices are shown and discussed.

2606.10103 2026-06-10 physics.chem-ph 新提交

Minimization of disorder as a key design principle for natural sizes of light harvesting 2 complexes

无序最小化作为光捕获2复合物自然尺寸的关键设计原则

Kwang Hyun Cho, Seogjoo J. Jang, Young Min Rhee

AI总结 通过全原子分子动力学模拟,发现天然LH2复合物的9重对称结构比非天然的6重和12重对称结构具有更小的准静态无序,表明自然尺寸旨在最小化能量无序以优化能量传递。

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AI中文摘要

紫色细菌的光捕获2(LH2)复合物具有优异的能量转换效率。在原子水平上阐明这种效率背后的设计原则对于理解其结构-功能关系至关重要,并可用于人工光捕获系统的设计。为此,我们对具有9重对称性的天然LH2复合物及其具有6重和12重对称性的两种非天然计算机模拟类似物中色素分子的电子激发态的动力学和统计性质进行了全面的计算研究。为了确保可靠且高效的全原子分子动力学模拟,我们将用于构建势能面的成熟插值方法与神经网络机器学习方法相结合。这些计算的结果表明,非天然形式的LH2型复合物比天然复合物具有显著更大的准静态无序。此外,非天然系统中氢键的破坏更多,强调了氢键在减少无序中的关键作用。另一方面,局部环境动力学对结构变化相对不敏感,尽管合成系统的非谐或原子间组分有适度增强。这些基于全原子模拟的发现提供了直接的计算证据,表明天然LH2复合物的结构和尺寸旨在最小化能量无序。我们分析了这些对LH2复合物能量传递能力的定量影响。

英文摘要

The light harvesting 2 (LH2) complex of purple bacteria has excellent energy conversion efficiency. Clarifying the design principle behind such efficiency at the atomistic level is crucial for understanding its structure-function relationship, and can be utilized for the design of artificial light harvesting systems. To this end, we conducted comprehensive computational investigation of the dynamical and statistical nature of electronic excited states of pigment molecules in a natural LH2 complex with 9-fold symmetry and its two non-natural {\it in silico} analogues with 6- and 12-fold symmetries. To ensure reliable and efficient all-atomistic molecular dynamics simulations, we combined a well established interpolation approach for the construction of the potential energy surface with a neural network machine learning approach. Outcomes of these calculations clarify that non-natural forms of LH2-type complexes have significantly larger quasistatic disorder than those for the natural one. In addition, non-natural systems have more disruptions of the hydrogen bonding, underscoring its crucial role for reducing the disorder. On the other hand, local environmental dynamics are relatively insensitive to the structural changes although there is moderate enhancement in the anharmonic or interatomic components for the synthetic ones. These findings based on all-atomistic simulations provide direct computational evidence that the structure and sizes of natural LH2 complexes are designed to minimize the energetic disorder. We analyze quantitative implications of these for the energy transferring capability of the LH2 complex.

2606.10060 2026-06-10 physics.gen-ph 新提交

New sum rules of the Koide type

Koide类型的新求和规则

Alejandro Rivero

AI总结 提出一种逆形式的Koide型质量规则,应用于下夸克扇区,精度与带电轻子直接求和规则相当,并发现Koide比率在280 TeV附近精确达到2/3。

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Journal ref
Physics Letters B, Volume 877 (2026), 140510
AI中文摘要

我们报告了一个逆形式的Koide型质量规则,\[m_i=M^{(d)} (w_0+w_i)^{-2}.\] 它适用于下夸克扇区,其数值精度与直接带电轻子求和规则 $m_i=M^{(l)} (z_0+z_i)^{2}$ 相当。对于中心质量值,在标准模型重整化群运行下,Koide比率在280 TeV附近精确达到 $2/3$。我们还回顾了涉及夸克的其他直接类型规则。

英文摘要

We report a mass rule of Koide type with inverse shape, \[m_i=M^{(d)} (w_0+w_i)^{-2}.\] It applies to the down-quark sector with numerical precision comparable to that of the direct charged-lepton sum rule $m_i=M^{(l)} (z_0+z_i)^{2}$. For central mass values, Koide ratio reaches exactly $2/3$ near 280 TeV under Standard Model renormalisation-group running. We also review other rules of the direct kind involving quarks.

2606.10034 2026-06-10 physics.chem-ph 新提交

Electron Paramagnetic Resonance Study of Radical Species on NaNbO3@CeO2-Modified Carbon Vulcan XC72 Gas Diffusion Electrode for Electrochemical Degradation of Paracetamol via Electro-Fenton

NaNbo3@CeO2修饰碳Vulcan XC72气体扩散电极电芬顿降解对乙酰氨基酚中自由基物种的电子顺磁共振研究

Caio Machado Fernandes, Joao Paulo C. Moura, Aline B. Trench, Rafael Sotana, Ana Maria P. Neto, Willy G. Santos, Mauro C. Santos

AI总结 利用EPR直接定量分析新型GDE电极降解对乙酰氨基酚中的自由基,发现BDD阳极优于Pt,15分钟完全降解,矿化率81.6%。

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AI中文摘要

虽然电化学氧化是一种有前景的水处理技术,但对药物降解中具体自由基机制的基本理解仍然有限。本研究通过使用电子顺磁共振(EPR)光谱直接定量分析在采用NaNbo3纳米立方体和CeO2纳米棒修饰的新型气体扩散电极(GDE)降解对乙酰氨基酚过程中产生的自由基物种,填补了这一空白。该方法从间接推断转向直接、定量分析活性物种,代表了相比先前文献的关键进步。结果表明,硼掺杂金刚石(BDD)阳极(65%羟基自由基,35%芳基自由基)显著优于铂(Pt)阳极(74%羟基自由基,26%芳基自由基),在15分钟内实现完全降解,而Pt需要45分钟,矿化率分别为81.6%和67.8%。因此,本研究提供了一个基础性的机理框架,从根本上推动了该领域的发展,不仅提供了一种更有效的材料体系(BDD/NaNbo3@CeO2-GDE),还提供了一种基于可量化自由基途径合理设计和优化电化学水处理过程的验证方法。

英文摘要

While electrochemical oxidation is a promising technology for water treatment, a fundamental understanding of the specific radical mechanisms involved in pharmaceutical degradation has remained limited. This study addresses this gap by employing Electron Paramagnetic Resonance (EPR) spectroscopy to directly quantify the radical species generated during the degradation of paracetamol using a novel gas diffusion electrode (GDE) modified with NaNbO3 nanocubes and CeO2 nanorods. This approach provides a critical advancement beyond prior literature by moving from indirect inference to direct, quantitative analysis of reactive species. Results demonstrated that a boron-doped diamond (BDD) anode (65% OH radical, 35% aryl radicals) drastically outperformed a Platinum (Pt) anode (74% OH radical, 26% aryl radicals), achieving complete degradation in 15 minutes versus 45 minutes and 81.6% versus 67.8% mineralization. Consequently, this work provides a foundational mechanistic framework that fundamentally advances the field, offering not just a more effective material system (BDD/NaNbO3@CeO2-GDE) but also a validated methodology for rationally designing and optimizing electrochemical water treatment processes based on quantifiable radical pathways.

2606.11153 2026-06-10 nucl-th physics.atom-ph 新提交

Quantum Monte Carlo calculations of Zemach moments in $A\leq 9$ nuclei

$A\leq 9$ 原子核中Zemach矩的量子蒙特卡洛计算

Garrett B. King, Sonia Bacca, Graham Chambers-Wall, Alex Gnech, Saori Pastore, Maria Piarulli, Robert B. Wiringa

AI总结 利用量子蒙特卡洛方法和手征有效场论核力,计算轻核的Zemach半径和电磁矩,发现$^6$Li的Zemach半径大于原子测量值,$^9$Be的结果与实验一致。

Comments 2 figures, 9 pages

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AI中文摘要

现代原子光谱学已达到如此高的精度,以至于核结构效应不能再被忽略,必须可靠地量化。特别是,超精细分裂依赖于Zemach半径,它编码了核电荷和磁化分布的卷积。第三个电Zemach矩提供了一个相关的有限尺寸度量,并进入μ子原子中兰姆位移的弹性双光子交换贡献。在这里,我们使用现代\textit{ab initio}核理论中的量子蒙特卡洛技术计算轻核的Zemach半径和其他电磁矩。使用在手征有效场论中导出的Norfolk两体和三体相互作用,我们评估了模型依赖性并研究了两体流的作用。对于$^6$Li,我们得到的Zemach半径大于原子测量提取的值,与最近的计算一致,证实了差异不是核模型的伪影。对于$^9$Be,我们的结果与实验一致;先前现象学评估的差异追溯到磁半径的模型依赖输入。

英文摘要

Modern atomic spectroscopy has reached a level of precision at which nuclear-structure effects can no longer be neglected and must be quantified reliably. In particular, hyperfine splittings depend on the Zemach radius, which encodes the convolution of the nuclear charge and magnetization distributions. The third electric Zemach moment provides a related finite-size measure and enters the elastic two-photon-exchange contribution to the Lamb shift in muonic atoms. Here, we compute Zemach radii and other electromagnetic moments for light nuclei using quantum Monte Carlo techniques within modern \textit{ab initio} nuclear theory. Using Norfolk two- and three-body interactions derived within chiral effective field theory, we assess the model dependence and study the role of two-body currents. For $^6$Li, we obtain a Zemach radius larger than that extracted from atomic measurements, consistent with recent calculations, confirming that the discrepancy is not an artifact of the nuclear model. For $^9$Be, our results agree with experiment; the discrepancy of previous phenomenological evaluations is traced to a model-dependent input for the magnetic radius.

2606.10567 2026-06-10 nucl-th 新提交

Simultaneous $αβ$ Decay: A New Mode of Nuclear Instability

同时αβ衰变:一种新的核不稳定性模式

Wenqiang Zhang, Chong Qi

AI总结 提出同时αβ衰变作为强相互作用和弱相互作用在单一量子跃迁中耦合的新核衰变模式,建立理论框架预测分支比和α能谱,发现与已知β延迟α发射体的关联。

Comments 5 pages, 2 figures

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AI中文摘要

我们提出同时αβ衰变作为一种新的核不稳定性模式,它涉及强相互作用和弱相互作用在单一量子跃迁中的耦合。我们建立了一个理论框架来预测其分支比和α能谱,根据单个α和β通道是关闭还是开放,确立了排他性和包容性判据。对核素图的全局调查确定了五个排他性αβ⁻候选体,均预测为实验上不可达,并排名了αβ⁻和αβ⁺模式的主要包容性候选体。值得注意的是,六个顶级αβ⁺候选体与已知的β延迟α发射体重合。观测到的α能谱自然地由同时αβ⁺发射解释,表明直接衰变是主导的底层机制。我们的发现确立了同时αβ衰变作为一种独特的放射性过程,并作为强相互作用和弱相互作用之间相互作用的灵敏探针。

英文摘要

We propose simultaneous $αβ$ decay as a novel mode of nuclear instability that involves the strong and weak interactions in a single quantum transition. We develop a theoretical framework to predict its branching ratios and $α$-energy spectra, establishing exclusive and inclusive criteria based on whether the individual $α$ and $β$ channels are closed or open. A global survey of the nuclear chart identifies five exclusive $αβ^-$ candidates, all predicted to be experimentally inaccessible, and ranks the leading inclusive candidates for both the $αβ^-$ and $αβ^+$ modes. Remarkably, six of the top $αβ^+$ candidates coincide with known $β$-delayed-$α$ precursors. The observed $α$ spectra are naturally accounted for by simultaneous $αβ^+$ emission, suggesting direct decay as the dominant underlying mechanism. Our findings establish simultaneous $αβ$ decay as a distinct radioactive process and a sensitive probe of the interplay between the strong and weak interactions.

2606.10341 2026-06-10 nucl-th 新提交

Global polarization of $Λ$, $Ξ^{-}$, and $Ω^{-}$ hyperons in Au+Au collisions at RHIC BES-II energies

RHIC BES-II能量下Au+Au碰撞中$Λ$、$Ξ^{-}$和$Ω^{-}$超子的全局极化

Gen-Hui Li, Cong Yi, Xiang-Yu Wu, Shi Pu, Guang-You Qin

AI总结 基于(3+1)维粘性流体动力学CLVisc和SMASH初始条件,使用修正Cooper-Frye公式研究RHIC BES-II能量下Au+Au碰撞中Λ、Ξ⁻和Ω⁻超子的全局极化,发现Ω⁻极化系统更大但低于STAR测量,超子-反超子极化劈裂随能量降低而增大。

Comments 8 pages, 4 figures

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AI中文摘要

我们研究了在RHIC束流能量扫描II(BES-II)能量范围$\sqrt{s_{NN}}=7.7$--$27$ GeV的Au+Au碰撞中$\Lambda$超子以及多奇异超子$\Xi^{-}$和$\Omega^{-}$的全局自旋极化。极化计算采用修正的Cooper--Frye公式,该公式包含热涡度、热剪切张量和重子化学势梯度的贡献,并结合了具有SMASH初始条件的(3+1)维粘性流体动力学框架CLVisc。我们给出了全局极化随碰撞能量、中心度、横向动量和快度的变化。我们发现$\Omega^{-}$的全局极化系统性地大于$\Lambda$和$\Xi^{-}$,因为其自旋量子数更大,但仍低于近期STAR测量的中心值。这一差异可能表明存在额外机制,例如$\Omega^{-}$内部奇异夸克之间的自旋关联,对观测到的$\Omega^{-}$极化有贡献。我们还发现,超子与反超子之间的全局极化劈裂在较低碰撞能量下增大,并且主要由化学势梯度贡献主导。

英文摘要

We investigate the global spin polarization of $Λ$ hyperons and the multi-strange hyperons $Ξ^{-}$ and $Ω^{-}$ in Au+Au collisions across the RHIC Beam Energy Scan II (BES-II) energy range, $\sqrt{s_{NN}}=7.7$--$27$ GeV. The polarization is computed using the modified Cooper--Frye formula, which includes contributions from thermal vorticity, the thermal shear tensor, and the gradient of the baryon chemical potential, combined with the (3+1)-dimensional viscous hydrodynamic framework CLVisc with SMASH initial conditions. We present the global polarization as a function of collision energy, centrality, transverse momentum, and rapidity. We find that the global polarization of $Ω^{-}$ is systematically larger than those of $Λ$ and $Ξ^{-}$ because of its larger spin quantum number, but it remains below the central value of the recent STAR measurement. This discrepancy may suggest that additional mechanisms, such as spin correlations among strange quarks inside the $Ω^{-}$, could contribute to the observed $Ω^{-}$ polarization. We also find that the global-polarization splitting between hyperons and anti-hyperons increases toward lower collision energies and is dominated by the chemical-potential-gradient contribution.

2606.11048 2026-06-10 physics.atom-ph nucl-ex quant-ph 新提交

Colloquium: Nuclear clocks

Colloquium: 核钟

Andrei Derevianko, R. Elwell, Eric R. Hudson

AI总结 本文综述了Th-229核同质异能态作为高精度核光学钟候选的研究进展,包括直接激光激发突破、离子阱与固态平台设计、系统学效应及其对基本常数变化的敏感性。

Comments 24 pages, 3 figures, 164 references

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AI中文摘要

Th-229核同质异能态在所有已知核激发态中能量最低,使其处于当前台式激光技术可及范围内。这一非凡特性使该核同质异能态成为极具吸引力的候选者,可用于构建超高精度和准确度的核光学钟,无论是作为孤立捕获的Th-229离子还是嵌入固态平台。近年来,由于直接激光激发方面的突破,围绕Th-229的研究活动激增。本文将阐明产生这一独特同质异能态的核物理基础,以及近半个世纪以来导致其直接激发的努力。将讨论Th-229核钟的设计和系统学,包括离子阱和固态平台。这些系统学效应,如频移和淬灭通道,既可用于探测局部化学环境,也可作为时钟操作中的控制旋钮。最后,将讨论核钟对基本常数变化的高度敏感性。

英文摘要

The Th-229 nuclear isomeric state has the lowest energy of all known nuclear excited states, placing it within the reach of current table-top laser technology. This extraordinary property has made this nuclear isomer an attractive candidate for a nuclear optical clock of incredibly high precision and accuracy, both as isolated trapped Th-229 ions and embedded into solid-state platforms. Activity around Th-229 has surged in recent years, driven by breakthroughs in its direct laser excitation. The underlying nuclear physics that gives rise to this unique isomer will be elucidated, as well as the nearly half-century of efforts that led to its direct excitation. The design and systematics of a Th-229 nuclear clock will be discussed, both in ion traps and in the solid-state. These systematics, such as frequency shifts and quenching channels, can be leveraged both to probe the local chemical environment, and as a control knob during clock operation. Finally, the nuclear clock's high sensitivity to the variations of fundamental constants will be discussed.

2606.10950 2026-06-10 physics.ins-det nucl-ex 新提交

Feasibility demonstration of continuous signal-based neutron noise measurements by experiments and simulations

基于连续信号的中子噪声测量可行性的实验与仿真验证

Máté István Boros, Máté Szieberth, Gergely Klujber, Imre Pázsit, István Barth, Yasunori Kitamura, Tsuyoshi Misawa

AI总结 通过实验和仿真验证了基于连续探测器电流的中子噪声分析方法,利用探测器对或反卷积消除脉冲形状畸变,在高计数率下准确估计瞬发中子衰减常数α,为高计数率反应堆噪声诊断提供实用替代方案。

Comments Manuscript submitted to Progress in Nuclear Energy

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AI中文摘要

中子噪声方法用于确定瞬发中子衰减常数等动力学参数,但传统的脉冲计数在高探测率下存在死时间和堆积问题。最近的理论表明,如果适当处理脉冲形状效应,分析连续探测器电流可以避免这些限制。本文基于在两个研究反应堆进行的仿真和实验,展示了连续信号中子噪声分析的可行性研究。应用探测器电流的随机模型推导了Rossi型和Feynman型公式,并通过使用探测器对或通过逆傅里叶和维纳滤波反卷积平均脉冲形状来减轻脉冲形状畸变。仿真表明,在脉冲计数变得不可用的计数率下,可以准确估计α参数,并且能够评估显著更高的α值。在KUCA和BME TR的测量证实,尽管存在死时间和电子伪影,连续和解卷积信号仍能提供无偏结果,将该方法确立为高计数率反应堆噪声诊断的实用替代方案。

英文摘要

Neutron noise methods are used to determine kinetic parameters such as the prompt neutron decay constant, but traditional pulse-counting suffers from dead-time and pile-up at high detection rates. Recent theory shows that analysing the continuous detector current can avoid these limitations if pulse-shape effects are properly treated. This work presents a feasibility study of continuous-signal neutron noise analysis based on simulations and experiments performed at two research reactors. The stochastic model of the detector current is applied to derive Rossi- and Feynman-type formulations, and pulse-shape distortions are mitigated using detector pairs or by deconvolving the average pulse-shape through inverse Fourier and Wiener filtering. Simulations demonstrate accurate $α$-parameter estimation at count rates where pulse-counting becomes unusable, and enable evaluation of significantly higher $α$ values. Measurements at KUCA and BME TR confirm that continuous and deconvolved signals provide unbiased results despite dead-time and electronic artifacts, establishing the method as a practical alternative for high-rate reactor noise diagnostics.

2606.09920 2026-06-10 physics.ins-det nucl-ex 新提交

Absolute intensity measurement of pulsed muon beams using in-beam activation

使用束内活化法对脉冲μ子束进行绝对强度测量

R. Mizuno, M. Niikura, T. Matsuzaki, A. D. Hillier, K. Ishida, S. Kawase, T. Kawata, K. Kitafuji, D. Tomono

AI总结 针对脉冲μ子束中μ子数量难以确定的问题,发展了基于μ子核俘获反应后残余核β延迟γ射线产额的方法,并测量了天然Cu、Zn、Ag的产额分支比,发现natAg(μ⁻, ν_μ x)¹⁰⁷ᵐPd反应适合作为μ子数校准参考。

Comments 9 pages, 3 figures

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AI中文摘要

束流中负μ子的绝对数量对于加速器设施中的许多实验至关重要,但在脉冲束中确定它一直很困难,尤其是在高强度下。最近,利用μ子核俘获反应后残余核的β延迟γ射线产额的方法被开发出来,用于确定脉冲μ子束中的μ子数。特别是,束内活化法采用短寿命同位素,使得通过照射μ子束在短时间内测量束流强度成为可能。然而,只有有限数量的同位素具有可靠的产额分支比(BR)测量值,而这是确定脉冲束中绝对μ子数所必需的。为了寻找适合束内活化法的新候选同位素,测量了天然丰度Cu、Zn和Ag在μ子核俘获反应后的产额分支比。综合考虑BR强度、μ子俘获概率、探测器的实际探测效率以及周围结构中靶材的稀有性,发现反应natAg(μ⁻, ν_μ x)¹⁰⁷ᵐPd可作为μ子数校准的有用参考。

英文摘要

The absolute number of negative muons contained in a beam is essential for many experiments at accelerator facilities, but determining it in pulsed beams has been difficult, particularly at high intensities. The method utilizing the yield of the $β$ delayed $γ$ rays from the residual nuclei after the muon nuclear capture reaction has recently been developed to determine the muon number in the pulsed muon beam. In particular, the in-beam activation method employs isotopes with short lifetimes, enabling the beam intensity to be measured over a short period with irradiating muon beams. However, only a limited number of isotopes have reliable measurements of production branching ratios (BRs), which are required to determine the absolute muon number in the pulsed beam. To search for new candidate isotopes that are suitable for in-beam activation method, the production branching ratio after the muon nuclear capture reaction was measured for natural abundance Cu, Zn, and Ag. Considering the strength of the BR, the muon capture probability, the practical detection efficiency of the detector, and rarity of the target material in the surrounding structures, the reaction $^\mathrm{nat}$Ag ($μ^-, ν_μx$) $^{107m}$Pd is found to be a useful reference for the muon number calibration.

2606.11143 2026-06-10 nucl-ex nucl-th 新提交

Hindered $ΔK=1$ Dipole Strength in octupole bands in $N=90$ $^{154}$Gd from Lifetime Measurements with $γ-γ$ fast timing technique

受阻的 $ΔK=1$ 偶极强度在 $N=90$ $^{154}$Gd 八极带中:来自 $γ-γ$ 快定时技术的寿命测量

A. Pal, S. Basak, D. Kumar, T. Bhattacharjee, B. Maheshwari, K. Nomura, P. Van Isacker, D. Banerjee, S. S. Alam, A. K. Jain

AI总结 通过γ-γ快定时技术测量$^{154}$Gd中低能负宇称态的寿命,提取绝对B(E1)跃迁强度,发现ΔK=1偶极强度显著受阻。

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AI中文摘要

利用位于加尔各答VECC的VENTURE阵列的γ-γ快定时技术,测量了$^{154}$Gd中1414 keV的$1^-$态和1398 keV的$2^-$态的寿命。这些态通过$^{154}$Tb的β衰变布居,$^{154}$Tb由K130回旋加速器上的质子诱导反应产生。从测量的寿命中,推导出绝对$B(E1)$跃迁强度。将提取的$B(E1)$值与相邻Gd同位素以及基于Gogny-HFB的$sdf$-IBM计算结果进行比较。结果表明,与相应的$ΔK=0$跃迁相比,这些态的$E1$强度受到强烈阻碍,为$^{154}$Gd中弱的$ΔK=1$偶极强度提供了证据。

英文摘要

The lifetimes of the low-lying negative-parity $1^-$ state at 1414~keV and $2^-$ state at 1398~keV in $^{154}$Gd have been measured using the $γ$--$γ$ fast-timing technique with the VENTURE array at VECC, Kolkata. The states were populated through the $β$ decay of $^{154}$Tb, produced in proton-induced reactions at the K130 cyclotron. From the measured lifetimes, absolute $B(E1)$ transition strengths were deduced. The extracted $B(E1)$ values are compared with those of neighboring Gd isotopes and with Gogny-HFB-based $sdf$-IBM calculations. The results show that the measured $E1$ strengths from these states are strongly hindered compared with the corresponding $ΔK=0$ transitions, providing evidence for weak $ΔK=1$ dipole strength in $^{154}$Gd.

2606.10948 2026-06-10 nlin.AO nlin.CD 新提交

Complexity synchronization as a diagnostic and control principle for adaptive systems

自适应系统的复杂性同步作为诊断与控制原则

Korosh Mahmoodi, Scott E. Kerick, Piotr J. Franaszczuk, David L. Boothe, Paolo Grigolini, Bruce J. West

AI总结 提出复杂性同步(CS)作为自适应系统的诊断与干预原则,通过多智能体模型验证其与协作性能的关系,揭示功能相关子系统并指导修复。

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AI中文摘要

自适应系统在依赖根本不同的内部协调模式时,可能表现出相似水平的性能。平均合作或收益等标准指标指示系统是否成功,但未揭示协调如何跨交互组件组织,或当性能失败时应针对哪些自适应变量。这里我们提出复杂性同步(CS),即耦合变量间演化时间复杂性的同步,作为自适应系统的诊断和干预指导原则。我们在一个由自私算法智能体组成的自适应多智能体系统中测试了这一想法,这些智能体在一个具有类似囚徒困境收益结构的简化捕食者-猎物模型中交互。使用滑动窗口修正扩散熵分析(MDEA)和去趋势波动分析(DFA)量化时间复杂性。CS定义为所得时间相关标度指数之间的相关性。在高交互机制下,基于MDEA的CS随协作性能增加而增加,而基于DFA的CS捕获了一种不同的持续性主导的协调模式。我们的结果表明,CS可以揭示功能相关的子系统,并为有针对性的修复提供原则性基础。更广泛地说,CS为理解和控制生物、社会、人机及其他自适应系统中的协调提供了通用的诊断和工程框架。

英文摘要

Adaptive systems can exhibit similar levels of performance while relying on fundamentally different internal modes of coordination. Standard metrics such as average cooperation or payoff indicate whether a system succeeds, but do not reveal how coordination is organized across interacting components or which adaptive variables should be targeted when performance fails. Here we propose complexity synchronization (CS), the synchronization of evolving temporal complexity across coupled variables, as a diagnostic and intervention guiding principle for adaptive systems. We test this idea in an adaptive multi agent system composed of Selfish Algorithm agents interacting in a reduced Predator Prey model with a Prisoners Dilemma like payoff structure. Temporal complexity is quantified using sliding window modified diffusion entropy analysis (MDEA) and detrended fluctuation analysis (DFA). CS is defined as the correlation between the resulting time dependent scaling exponents. In the high-interaction regime, MDEA-based CS increases with cooperative performance, whereas DFA based CS captures a distinct persistence dominated coordination mode. Our results show that CS can reveal functionally relevant subsystems and provide a principled basis for targeted repair. More broadly, CS offers a general diagnostic and engineering framework for understanding and controlling coordination in biological, social, human machine, and other adaptive systems.

2606.10727 2026-06-10 nlin.SI math.AP 新提交

Long-time Asymptotics of a Full Camassa-Holm Soliton Gas

完整Camassa-Holm孤子气体的长时间渐近行为

Dedi Yan, Xianguo Geng, Minxin Jia

AI总结 研究Camassa-Holm方程完整孤子气体的长时间渐近,通过纯孤子Riemann-Hilbert问题收敛到具有两个非零反射系数的极限问题,并利用Deift-Zhou非线性最速下降法分析,得到自相似平面三个椭圆波区的渐近公式。

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AI中文摘要

我们研究了Camassa-Holm方程完整孤子气体的长时间渐近行为。分析始于一个具有\(2N\)个极点和两种不同类型留数条件的纯孤子Riemann-Hilbert (RH)问题。我们证明,当\(N\to\infty\)时,这个离散RH问题收敛到一个极限孤子气体RH问题,其跳跃矩阵包含两个非零反射系数。在这个意义上,极限问题给出了Camassa-Holm方程的一个完整孤子气体模型,与之前研究的半孤子气体模型(其跳跃矩阵仅涉及一个非零反射系数)形成对比。极限RH问题通过Deift-Zhou非线性最速下降法分析。两个非零反射系数的存在要求跳跃矩阵的两种不同类型的三角分解,并导致更微妙的\(g\)-函数机制。主要困难在于构造适应Camassa-Holm相的合适\(g\)-函数,并精确控制它们在特殊点\(k=i/2\)和无穷远处的行为。根据谱端点\(\eta_1\)和\(\eta_2\)的位置,出现不同的\(g\)-函数机制。本文中,我们聚焦于情形I,并推导出自相似平面三个椭圆波区的长时间渐近公式。在每个区域,主导项由有限间隙椭圆函数给出,而在中心区域,首项修正是\(\mathcal O(t^{-1/2})\)量级,并涉及抛物柱函数。

英文摘要

We investigate the long-time asymptotics of a full soliton gas for the Camassa--Holm equation. The analysis starts from a pure-soliton Riemann--Hilbert (RH) problem with \(2N\) poles and two distinct types of residue conditions. We prove that, as \(N\to\infty\), this discrete RH problem converges to a limiting soliton gas RH problem whose jump matrix contains two nonzero reflection coefficients. In this sense, the limiting problem gives a full soliton gas model for the Camassa--Holm equation, in contrast to the previously studied half soliton gas models, whose jump matrices involve only one nonzero reflection coefficient. The limiting RH problem is analyzed by the Deift--Zhou nonlinear steepest descent method. The presence of two nonzero reflection coefficients requires two different types of triangular factorizations of the jump matrix and leads to a more delicate \(g\)-function mechanism. The main difficulty lies in the construction of suitable \(g\)-functions adapted to the Camassa--Holm phase, together with the precise control of their behavior near the distinguished point \(k=i/2\) and at infinity. Depending on the location of the spectral endpoints \(η_1\) and \(η_2\), different \(g\)-function mechanisms arise. In this paper, we focus on Case I and derive the long-time asymptotic formulas in three elliptic-wave regions of the self-similar plane. In each region, the leading term is given by a finite-gap elliptic function, while in the central region the first correction is of order \(\mathcal O(t^{-1/2})\) and involves parabolic cylinder functions.