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2303.09560 2026-05-08 eess.SY cs.SY math.PR

Methodology for Capacity Credit Evaluation of Physical and Virtual Energy Storage in Decarbonized Power System

物理和虚拟能源存储在去碳化电力系统中的容量信用评估方法

Ning Qi, Peng Li, Lin Cheng, Ziyi Zhang, Wenrui Huang, Weiwei Yang

AI总结 本文提出一种新框架评估物理和虚拟能源存储的容量信用,通过两阶段协调调度和不确定性建模,改进了存储系统的可靠性与容量信用评估。

Comments capacity credit, decision-dependent uncertainty, decarbonized power system

Journal ref Applied Energy, Vol. 396, 126310 (2025)

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AI中文摘要

能源存储(ES)和虚拟能源存储(VES)是实现电力系统脱碳的关键组成部分。尽管ES和VES已被证明能够提供多种电网服务,但迄今为止很少有工作提供了系统量化其充足贡献和可信容量价值的框架,同时考虑人类和市场行为。因此,本文提出了一种新的评估框架来评估ES和VES的容量信用(CC)。为了解决系统容量不足和存储市场行为问题,提出了一种两阶段协调调度,以在日前资源自我能源管理与实时故障高效调整之间取得平衡。我们进一步用存储操作建模了人类行为,并将两种决策无关不确定性(DIUs)(运行状态和自消费)和一种决策相关不确定性(DDUs)(可用容量)纳入所提出的调度中。此外,引入了新的可靠性和CC指数(例如等效物理存储容量(EPSC))来评估ES和VES的实际和理论充足贡献,以及在维持等效系统充足性的同时替代发电和物理存储的能力。基于IEEE RTS-79系统和实际数据的详尽案例研究验证了忽略DIUs和DDUs在先前工作中的显著后果(10%-70%高估CC),而所提出的方法优于其他方法,能够生成可信且现实的结果。最后,我们调查了影响ES和VES充足贡献的关键因素,并提供了合理建议,以更好地利用ES和VES在去碳化电力系统中的灵活性。

英文摘要

Energy storage (ES) and virtual energy storage (VES) are key components to realizing power system decarbonization. Although ES and VES have been proven to deliver various types of grid services, little work has so far provided a systematical framework for quantifying their adequacy contribution and credible capacity value while incorporating human and market behavior. Therefore, this manuscript proposed a novel evaluation framework to evaluate the capacity credit (CC) of ES and VES. To address the system capacity inadequacy and market behavior of storage, a two-stage coordinated dispatch is proposed to achieve the trade-off between day-ahead self-energy management of resources and efficient adjustment to real-time failures. And we further modeled the human behavior with storage operations and incorporate two types of decision-independent uncertainties (DIUs) (operate state and self-consumption) and one type of decision-dependent uncertainty (DDUs) (available capacity) into the proposed dispatch. Furthermore, novel reliability and CC indices (e.g., equivalent physical storage capacity (EPSC)) are introduced to evaluate the practical and theoretical adequacy contribution of ES and VES, as well as the ability to displace generation and physical storage while maintaining equivalent system adequacy. Exhaustive case studies based on the IEEE RTS-79 system and real-world data verify the significant consequence (10%-70% overestimated CC) of overlooking DIUs and DDUs in the previous works, while the proposed method outperforms other and can generate a credible and realistic result. Finally, we investigate key factors affecting the adequacy contribution of ES and VES, and reasonable suggestions are provided for better flexibility utilization of ES and VES in decarbonized power system.

2302.11420 2026-05-08 math-ph math.MP math.QA

Higher Courant-Dorfman algebras and associated higher Poisson vertex algebras

更高阶的Courant-Dorfman代数及其相关的更高阶Poisson顶点代数

Ryo Hayami

AI总结 本文研究了Courant-Dorfman代数与Poisson顶点代数之间更高阶关系,定义了更高阶Courant-Dorfman代数,并探讨其与带状辛几何的关系,给出了非退化情况下的-阶带状Poisson代数,并通过有限维向量丛构造了更高阶Courant-Dorfman代数。

Comments 28 pages, significantly revised

Journal ref Journal of Geometry and Physics Volume 227, 2026

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AI中文摘要

在本文中,我们考虑了Courant-Dorfman代数与Poisson顶点代数之间更高阶关系的观念。我们定义了更高阶Courant-Dorfman代数,并研究其与带状辛几何的关系。特别是,我们给出了非退化情况下的-阶带状Poisson代数。对于来自有限维向量丛的更高阶Courant-Dorfman代数,它们与相应的带状辛流形的函数代数一致。我们定义了更高阶李 conformal 代数和Poisson顶点代数,并给出了由此产生的更高阶(弱)Courant-Dorfman代数结构。此外,我们证明了更高阶李 conformal 代数和更高阶Poisson顶点代数具有类似于李 conformal 代数和Poisson顶点代数的性质。作为例子,我们得到了Batalin-Fradkin-Vilkovisky(BFV)电流代数的代数描述。

英文摘要

In this paper, we consider a notion of a higher version of the relation between Courant-Dorfman algebras and Poisson vertex algebras. We define a higher Courant-Dorfman algebra, and study the relationship with graded symplectic geometry. In particular, we give graded Poisson algebras of degree $-n$ in the non-degenerate case. For higher Courant-Dorfman algebras coming from finite-dimensional vector bundles, they coincide with the algebras of functions of the associated differential-graded(dg) symplectic manifolds of degree $n$. We define a higher Lie conformal algebra and Poisson vertex algebra, and give a higher (weak) Courant-Dorfman algebraic structure arising from them. Moreover, we prove that the higher Lie conformal algebras and higher Poisson vertex algebras have properties like Lie conformal algebras and Poisson vertex algebras. As an example, we obtain an algebraic description of Batalin-Fradkin-Vilkovisky(BFV) current algebras.

2301.06829 2026-05-08 cond-mat.mes-hall cond-mat.mtrl-sci

Berry-Phase Breakdown and Semiclassical Reconciliation in Topological Dirac Fock-Darwin states

Berry相破环与拓扑Dirac Fock-Darwin态的半经典调和

Ye-ping Jiang

AI总结 研究拓扑绝缘体表面圆环n-junction中Dirac费米子类人工原子(Fock-Darwin态)的Berry相切换失效现象,揭示电子-空穴核心壳层结构在临界点附近演变,通过半经典方法调和理论与实验结果。

Comments 15 pages, 4 figures

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AI中文摘要

我研究了拓扑绝缘体表面圆环n-junction中Dirac费米子类人工原子(Fock-Darwin态)的Berry相切换失效现象。在非抛物势中,FD态表现出独特的电子-空穴核心壳层结构,其中严格的Berry相切换(BPS)图景在临界点附近失效:被困电子核心态演变为量化蛇态的包络函数。这与实验中观察到的尖锐BPS相矛盾。然而,当将这些包络函数视为有效受限态时,BPS场景仍然成立,从而调和了理论与实验。通过实验跟踪了场驱动从静电到Landau能级限制的演变,直至14 T,并通过模拟得到支持,确立拓扑表面态作为Dirac物理可调平台,超越传统量子点。

英文摘要

I investigate the two-dimensional Dirac fermion analogue of artificial atoms (Fock-Darwin states, FD) in a circular n-p junction on a topological insulator surface. The FD states in this non-parabolic potential exhibit a unique electron-hole core-shell structure, where the strict Berry-phase switch (BPS) picture breaks down near criticality: the trapped electron-core states evolve into the envelope functions of quantized snake states. This contradicts the sharp BPS seen in experiments. Nevertheless, the BPS scenario remains valid when treating these envelope functions as effective confined states, thereby reconciling theory with experiment. The field-driven evolution from electrostatic to Landau-level confinement is tracked to 14 T experimentally and supported by simulations, establishing topological surface states as a tunable platform for Dirac physics beyond conventional quantum dots.

2211.03600 2026-05-08 math.AP

Compressible Gravity-Capillary Water Waves with Vorticity: Local Well-Posedness, Incompressible and Zero-Surface-Tension Limits

可压缩的重力-表面张力水波与涡旋:局部well-posed性,不可压缩和零表面张力极限

Chenyun Luo, Junyan Zhang

AI总结 本文研究了具有涡旋的可压缩重力-表面张力水波,通过精心设计的近似系统和双曲方法证明了局部well-posed性,同时获得不可压缩和零表面张力极限。

Comments 77 pages. v6: Final version, accepted by J. Differ. Equ. v5: add the result of improved incompressible limit

Journal ref J. Differ. Equ., 472 (2026), 114444

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AI中文摘要

我们考虑了描述无界初始域中液体运动的3D可压缩等熵欧拉方程,该液体具有移动边界和固定平面底面,深度有限。液体受重力和表面张力影响,不假设为无涡旋。通过结合精心设计的近似系统和双曲方法,我们证明了局部well-posed性,避免了使用Nash-Moser迭代。能量估计不导致正则性损失,并且在满足Rayleigh-Taylor符号条件时,对于马赫数和表面张力系数是均匀的。因此,我们同时获得了不可压缩和零表面张力极限。此外,通过应用偏微分算子 calculus 到自由表面演化的分析,可以去掉对高阶时间导数的均匀有界性要求。

英文摘要

We consider the 3D compressible isentropic Euler equations describing the motion of a liquid in an unbounded initial domain with a moving boundary and a fixed flat bottom at finite depth. The liquid is under the influence of gravity and surface tension, and it is not assumed to be irrotational. We prove local well-posedness by combining a carefully designed approximate system and a hyperbolic approach, which allows us to avoid using Nash-Moser iteration. The energy estimates yield no regularity loss and are uniform in both Mach number and surface tension coefficient, provided the Rayleigh-Taylor sign condition is satisfied. We thus simultaneously obtain incompressible and zero surface tension limits. Moreover, we can drop the uniform boundedness (with respect to Mach number) on high-order time derivatives by applying the paradifferential calculus to the analysis of the free-surface evolution.

2206.00578 2026-05-08 physics.comp-ph

Extending OpenKIM with an Uncertainty Quantification Toolkit for Molecular Modeling

向分子建模扩展开放KIM以包含不确定性量化工具包

Yonatan Kurniawan, Cody L. Petrie, Mark K. Transtrum, Ellad B. Tadmor, Ryan S. Elliott, Daniel S. Karls, Mingjian Wen

AI总结 本文提出在KLIFF中加入不确定性量化工具包,用于评估原子模拟的可靠性,通过PTMCMC方法估计IP功能形式的不确定性,并展示Stillinger-Weber势在硅原子能和力预测中的应用。

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AI中文摘要

原子模拟是材料建模的重要工具。相互作用势(IPs)是此类分子模型的核心,模型预测的准确性依赖于IP的选择。不确定性量化(UQ)是评估原子模拟可靠性的新兴工具。开放相互作用势知识库(OpenKIM)是一个旨在收集和标准化IP研究的计算基础设施项目,以实现透明、可重复的研究。OpenKIM框架的一部分是Python包KIM-based Learning-Integrated Fitting Framework(KLIFF),它提供了用于IP参数拟合的工具。本文介绍了一个UQ工具包扩展到KLIFF。我们关注两种不确定性来源:参数变化和IP功能形式的不足。我们的实现使用并行温度马尔可夫链蒙特卡洛(PTMCMC),调整采样温度以估计IP功能形式的不确定性。我们演示了Stillinger--Weber势在钻石配置下对硅原子能和力的预测。最后,我们强调了应用和使用这些工具的一些潜在细微之处,并为从业者和IP开发者提供建议。

英文摘要

Atomistic simulations are an important tool in materials modeling. Interatomic potentials (IPs) are at the heart of such molecular models, and the accuracy of a model's predictions depends strongly on the choice of IP. Uncertainty quantification (UQ) is an emerging tool for assessing the reliability of atomistic simulations. The Open Knowledgebase of Interatomic Models (OpenKIM) is a cyberinfrastructure project whose goal is to collect and standardize the study of IPs to enable transparent, reproducible research. Part of the OpenKIM framework is the Python package, KIM-based Learning-Integrated Fitting Framework (KLIFF), that provides tools for fitting parameters in an IP to data. This paper introduces a UQ toolbox extension to KLIFF. We focus on two sources of uncertainty: variations in parameters and inadequacy of the functional form of the IP. Our implementation uses parallel-tempered Markov chain Monte Carlo (PTMCMC), adjusting the sampling temperature to estimate the uncertainty due to the functional form of the IP. We demonstrate on a Stillinger--Weber potential that makes predictions for the atomic energies and forces for silicon in a diamond configuration. Finally, we highlight some potential subtleties in applying and using these tools with recommendations for practitioners and IP developers.

2203.13425 2026-05-08 physics.atom-ph

Scattering-asymmetry control with ultrafast electron wave packet shaping

利用超快电子波包形变控制散射不对称性

Yuya Morimoto, Peter Hommelhoff, Lars Bojer Madsen

AI总结 通过超快电子波包在动量空间的形变控制散射不对称性,研究电子波包与原子的相互作用及弹性散射特性。

Comments 22 pages, 6 figures

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AI中文摘要

紧聚焦电子束与原子的散射是现代电子显微镜的基础之一。当目标原子偏离束中心时,会出现基本对称性破缺,导致束偏转和散射电子的不对称角分布。本文提出了一种概念,通过在阿托秒到皮秒时间尺度上形变入射高能电子波包,以控制散射不对称性的符号和大小。形变控制波包的超快实空间动力学,改变波包对参数依赖的量子干涉和动量分布的两种竞争贡献之间的平衡。我们发现弹性散射对波包性质的高度敏感性,这种效应将允许在超快电子显微镜中对波包和目标进行表征。

英文摘要

Scattering of a tightly focused electron beam by an atom forms one of the bases of modern electron microscopy. A fundamental symmetry breaking occurs when the target atom is displaced from the beam center. This displacement results in a deflection of the beam and an asymmetric angular distribution of the scattered electrons. Here we propose a concept to control the sign and magnitude of the scattering asymmetry by shaping the incident high-energy electron wave packet in momentum space on the atto- to picosecond time scale. The shaping controls the ultrafast real-space dynamics of the wave packet, shifting the balance between two competing contributions of the impact-parameter-dependent quantum interference and the momentum distribution of the wave packet on the target. We find a strong sensitivity of the elastic scattering on the wave packet properties, an effect that will allow wave-packet and target characterization in ultrafast electron microscopy.

2112.04375 2026-05-08 quant-ph

Ancilla-Error-Transparent Controlled Beam Splitter Gate

辅助量子比特透明的受控光束分裂器门

Iivari Pietikäinen, Ondřej Černotík, Shruti Puri, Radim Filip, S. M. Girvin

AI总结 本文提出利用Kerr-猫量子比特实现受控光束分裂器门,该门可用于构建非门交换门,具有高保真度和对主导误差的透明性。

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AI中文摘要

在包含辅助量子比特和玻色子模的混合电路量子电动力学架构中,受控光束分裂器门是一种强大资源。它可以用于创建(至多受控奇偶性操作)一个辅助量子比特控制的玻色子模交换门。这是执行纯度`swap测试'、准备量子非高斯纠缠和直接测量量子态非线性功能的必要元素。它也构成了混合离散/连续变量量子计算的重要门。我们提出了一种新的混合cSWAP实现,利用`Kerr-cat'量子比特——受强双光子驱动的非谐振子。Kerr-cat用于生成受控相位光束分裂器(cPBS)操作。当与普通光束分裂器结合时,可获得受控光束分裂器(cBS),从而获得cSWAP。Kerr-cat的强偏置误差通道具有主导的相位翻转,这使cSWAP门变得非破坏性和对主导误差透明。我们的提案易于实现,并基于目前可用的实验参数,应能够实现具有高保真度的受控光束分裂器门,其保真度可与当前电路QED中的普通光束分裂器操作相媲美。

英文摘要

In hybrid circuit QED architectures containing both ancilla qubits and bosonic modes, a controlled beam splitter gate is a powerful resource. It can be used to create (up to a controlled-parity operation) an ancilla-controlled SWAP gate acting on two bosonic modes. This is the essential element required to execute the `swap test' for purity, prepare quantum non-Gaussian entanglement and directly measure nonlinear functionals of quantum states. It also constitutes an important gate for hybrid discrete/continuous-variable quantum computation. We propose a new realization of a hybrid cSWAP utilizing `Kerr-cat' qubits -- anharmonic oscillators subject to strong two-photon driving. The Kerr-cat is used to generate a controlled-phase beam splitter (cPBS) operation. When combined with an ordinary beam splitter one obtains a controlled beam-splitter (cBS) and from this a cSWAP. The strongly biased error channel for the Kerr-cat has phase flips which dominate over bit flips. This yields important benefits for the cSWAP gate which becomes non-destructive and transparent to the dominate error. Our proposal is straightforward to implement and, based on currently existing experimental parameters, should achieve controlled beam-splitter gates with high fidelities comparable to current ordinary beam-splitter operations available in circuit QED.

2112.02568 2026-05-08 quant-ph

Swap-test interferometry with biased ancilla noise

交换测试干涉度量学与偏向辅助噪声

Ondřej Černotík, Iivari Pietikäinen, Shruti Puri, S. M. Girvin, Radim Filip

AI总结 本文通过将线性镜替换为受控交换门和辅助量子比特测量,利用简单输入态实现Heisenberg标度的相位估计,展示了改进的相位灵敏度。

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AI中文摘要

Mach-Zehnder干涉仪是一种用于检测两束光之间微小相位偏移的强大设备。简单输入态如相干态或单光子可以达到标准量子极限,而更复杂的态可实现Heisenberg标度;然而,后者需要复杂的输入态,难以制备。因此,寻找高灵敏度相位估计需要非线性干涉仪,以更高效地制备这些复杂态。本文表明,当干涉仪中的线性镜被受控交换门替代,并对辅助量子比特进行测量时,简单输入态(包括Fock态和相干态)可恢复Heisenberg标度。这些交换测试将输入Fock态和相干态投影到NOON态和纠缠相干态,从而在干涉仪一个臂中提高对微小相位偏移的灵敏度。我们详细分析了辅助误差,表明使辅助态偏向相位翻转具有显著优势,并对可能在回路量子电动力学中实现的方案进行了彻底的数值模拟。我们的结果因此提供了一种可行的相位估计方法,接近Heisenberg极限灵敏度。

英文摘要

The Mach--Zehnder interferometer is a powerful device for detecting small phase shifts between two light beams. Simple input states -- such as coherent states or single photons -- can reach the standard quantum limit of phase estimation while more complicated states can be used to reach Heisenberg scaling; the latter, however, require complex states at the input of the interferometer which are difficult to prepare. The quest for highly sensitive phase estimation therefore calls for interferometers with nonlinear devices which would make the preparation of these complex states more efficient. Here, we show that the Heisenberg scaling can be recovered with simple input states (including Fock and coherent states) when the linear mirrors in the interferometer are replaced with controlled-swap gates and measurements on ancilla qubits. These swap tests project the input Fock and coherent states onto NOON and entangled coherent states, respectively, leading to improved sensitivity to small phase shifts in one of the interferometer arms. We perform detailed analysis of ancilla errors, showing that biasing the ancilla towards phase flips offers a great advantage, and perform thorough numerical simulations of a possible implementation in circuit quantum electrodynamics. Our results thus present a viable approach to phase estimation approaching Heisenberg-limited sensitivity.

2002.11766 2026-05-08 math.GR

Groups acting on trees with Tits' independence property (P)

具有Tits独立性质(P)的树上群作用(P)

Colin D. Reid, Simon M. Smith

AI总结 本文通过新的局部作用理论,对具有Tits独立性质(P)的树上闭群作用进行完整分类和描述,提供了从局部作用图构造群的方法,并能直接读取群的几何密度、紧生成性和简单性等性质。

Comments With an appendix by Stephan Tornier. Article has appeared (open access) in Mathematische Annalen. This arXiv update is the Author Accepted Version; it is not the Version of Record. The Version of Record is available online at https://doi.org/10.1007/s00208-026-03412-w

Journal ref Math. Ann. 395, 53 (2026)

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AI中文摘要

局部作用(顶点稳定子在该顶点邻居上的作用)自J.Tits于1970年引入独立性质(P)以来,已成为研究树上群作用的重要方法,尤其在2000年M.Burger和S.Mozes的论文后更为重要。这种“局部到整体”的方法对完全不连通的局部紧群理论的发展至关重要,因为它允许在保持顶点稳定子作用控制的同时构造非离散的树上群作用,这在传统Bass-Serre方法下难以实现。本文通过新的局部作用理论,对具有Tits独立性质(P)的树上闭群作用进行完整分类和描述,该理论是经典Bass-Serre理论的补充。一方面,该理论将群作用分解为“局部作用图”(编码所有“局部”信息的装饰图);另一方面,从给定的局部作用图构造群作用。可以直观地从局部作用图判断所得到的群是否具有几何密度、紧生成性和简单性等性质。

英文摘要

Local actions (actions of a vertex stabiliser on the neighbours of that vertex) have become an important approach to group actions on trees since J. Tits' introduction in 1970 of the independence property (P) and especially since a 2000 paper by M. Burger and Sh. Mozes. This `local-to-global' approach has been critical in the development of the theory of totally disconnected locally compact groups because it allows the construction of nondiscrete group actions on trees while keeping control over the action of a vertex stabiliser, in a way that is not practical under the classical Bass-Serre approach. The majority of constructions of nonlinear nondiscrete locally compact simple groups use (P) and its generalisations. In this article we give a full classification and description of all closed group actions on trees with Tits' independence property (P) using a new coherent theory for local actions that applies to all actions on trees. This theory is a `local action' complement to classical Bass-Serre theory. On the one hand, our theory gives a decomposition of a group acting on a tree into a `local action diagram' (a decorated graph that encodes all `local' information), and on the other hand a construction of a group acting on a tree from a given local action diagram. One can read directly from the local action diagram whether the resulting group has certain properties, like geometric density, compact generation and simplicity.

1909.09289 2026-05-08 quant-ph

Optimal preparation of the $W$ state for qubits with XY coupling

为具有XY耦合的量子位最优制备W态

Dalton Jones, Armin Rahmani

AI总结 利用退火模拟确定了将简单产物态转化为三量子位W态的最优协议,通过庞特里亚金最小原理分析了最优 bang-bang 协议,展示了其在实现特定量子门和目标态中的有效性。

Comments 7 pages, 5 figures, plus 4 pages of supplemental material

Journal ref Europhys. Lett. 154, 38003 (2026)

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AI中文摘要

利用退火模拟,我们发现了一种最优协议,该协议通过描述XY耦合和单量子位门的哈密顿量,将简单产物态演化为三量子位W态,并确定了相关的量子速度限制。应用庞特里亚金最小原理,我们全面表征了最优bang-bang协议。尽管泄漏影响性能,但这些协议对实现误差具有鲁棒性,并在弛豫和退相干时间内运行良好。我们的发现突显了庞特里亚金原理作为设计脉冲形状的强大工具,能够直接将设备交互与特定量子门和目标态联系起来。

英文摘要

Using simulated annealing, we find optimal protocols that evolve a simple product state into a three-qubit $W$ state with a Hamiltonian that describes XY coupling and single-qubit gates, and determine the associated quantum speed limit. Applying Pontryagin's minimum principle, we fully characterize the optimal bang-bang protocols. While leakage affects performance, the protocols remain robust to implementation errors and operate well within relaxation and decoherence times. Our findings highlight Pontryagin's principle as a powerful tool for designing pulse shapes that directly link device interactions to specific quantum gates and target states.

1803.09446 2026-05-08 math.NA cs.NA math.OC

Convergence of differentiable non-monotone schemes for fully nonlinear parabolic equations

可区分非单调方案对全非线性抛物方程的收敛性

Yumiharu Nakano

AI总结 本文提出非单调近似方案的收敛理论,通过两点一致性条件替代严格单调性,适用于全非线性抛物方程,并给出Hamilton-Jacobi-Bellman方程的定量误差界。

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AI中文摘要

我们为全非线性抛物偏微分方程的非单调近似方案开发了一种收敛理论。现代计算方法如基于核的置信度法、谱方法、物理启发式神经网络和深度伽辽金方法通常是非单调的,因为它们产生光滑的近似解并直接从所选假设函数的梯度计算空间导数。此类方案因此超出了经典Barles和Souganidis收敛理论的范围。我们引入了一个抽象框架,用两点一致性条件替代严格单调性,这两个条件分别针对PDE残差和终端不匹配,均可直接验证于光滑近似序列。技术关键是一个max-min表示,将非线性转换为粘性子解和超解不等式,从而在抽象论证中省略单调性。该框架在标准假设下提供定性收敛,同时为无界空间域上的Hamilton-Jacobi-Bellman方程提供定量误差界,在其中扩展截断圆柱上的残差与来自价值函数的基础控制随机微分方程的指数衰减尾项相平衡。作为具体实现,我们分析了基于Wendland径向基函数的核置信度法,并在一维和二维空间的基准Hamilton-Jacobi-Bellman问题上进行了数值实验,确认了预测的收敛行为。

英文摘要

We develop a convergence theory for non-monotone approximation schemes for fully nonlinear parabolic partial differential equations. Modern computational methods such as kernel-based collocation, spectral methods, physics-informed neural networks, and deep Galerkin methods are typically non-monotone, since they produce smooth approximate solutions and compute spatial derivatives directly from gradients of the chosen ansatz. Such schemes therefore lie outside the scope of the classical Barles and Souganidis convergence theory. We introduce an abstract framework that replaces strict monotonicity by two pointwise consistency conditions, on the PDE residual and on the terminal mismatch, both directly verifiable for a smooth approximating sequence. The technical key is a max-min representation of the nonlinearity that converts a vanishing classical residual into the viscosity subsolution and supersolution inequalities, and so dispenses with monotonicity in the abstract argument. The framework yields qualitative convergence under standard hypotheses, together with a quantitative error bound for Hamilton-Jacobi-Bellman equations on an unbounded spatial domain, in which the residual on an expanding truncation cylinder is balanced against an exponentially decaying tail term coming from the controlled stochastic differential equation underlying the value function. As a concrete realization, we analyze kernel-based collocation with Wendland radial basis functions, and present numerical experiments on a benchmark Hamilton-Jacobi-Bellman problem in one and two spatial dimensions that confirm the predicted convergence behaviour.

1803.01931 2026-05-08 math.CO cs.CG

Structure and generation of crossing-critical graphs

交叉临界图的结构与生成

Zdeněk Dvořák, Petr Hliněný, Bojan Mohar

AI总结 本文研究了需要至少c条边交叉的最小图,证明了对于c>1,存在无限多个c-交叉临界图,并给出了生成这些图的多项式时间算法。

Comments 53 pages, 5 figures; v2: extended version of the paper with the same title presented at 34th International Symposium on Computational Geometry (SoCG 2018); v3: minor update of the front page

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AI中文摘要

本文研究了需要至少c条边交叉的最小图,证明了对于c>1,存在无限多个c-交叉临界图,并给出了生成这些图的多项式时间算法。

英文摘要

We study $c$-crossing-critical graphs, which are the minimal graphs that require at least $c$ edge-crossings when drawn in the plane. For $c=1$ there are only two such graphs without degree-2 vertices, $K_5$ and $K_{3,3}$, but for any fixed $c>1$ there exist infinitely many $c$-crossing-critical graphs. It has been previously shown that $c$-crossing-critical graphs have bounded path-width and contain only a bounded number of internally disjoint paths between any two vertices. We expand on these results, providing a more detailed description of the structure of crossing-critical graphs. On the way towards this description, we prove a new structural characterisation of plane graphs of bounded path-width. Then we show that every $c$-crossing-critical graph can be obtained from a $c$-crossing-critical graph of bounded size by replicating bounded-size parts that already appear in narrow "bands" or "fans" in the graph. This also gives an algorithm to generate all the $c$-crossing-critical graphs of at most given order $n$ in polynomial time per each generated graph.

1803.00719 2026-05-08 cs.IR cs.SI

RankDCG: Rank-Ordering Evaluation Measure

RankDCG:排名顺序评估度量

Denys Katerenchuk, Andrew Rosenberg

AI总结 本文提出RankDCG,一种改进的nDCG算法,解决传统排名评估方法在处理同等级元素、评分不一致及成本函数等方面的问题,并在真实和构造数据集上验证其有效性。

Journal ref Proceedings of the 10th International Conference on Language Resources and Evaluation (LREC 2016), pp. 3675-3680

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AI中文摘要

排名被广泛应用于各类问题,尤其是信息检索(搜索)。存在多种流行的排名评估方法,如Kendall的τ、平均精度和nDCG。在处理用户排名或推荐系统等问题时,这些方法存在诸多问题,包括无法处理同等级元素、评分不一致和模糊的下界分数,以及不恰当的成本函数。我们提出了一种新的度量方法RankDCG,以解决这些问题。这是对流行nDCG算法的修改。我们为任何有效的排名算法提供了若干标准,并展示了只有RankDCG满足所有标准。在构造和真实数据集上展示了结果。我们发布了公开可用的RankDCG评估包。

英文摘要

Ranking is used for a wide array of problems, most notably information retrieval (search). There are a number of popular approaches to the evaluation of ranking such as Kendall's $τ$, Average Precision, and nDCG. When dealing with problems such as user ranking or recommendation systems, all these measures suffer from various problems, including an inability to deal with elements of the same rank, inconsistent and ambiguous lower bound scores, and an inappropriate cost function. We propose a new measure, rankDCG, that addresses these problems. This is a modification of the popular nDCG algorithm. We provide a number of criteria for any effective ranking algorithm and show that only rankDCG satisfies all of them. Results are presented on constructed and real data sets. We release a publicly available rankDCG evaluation package.

2605.05944 2026-05-08 math.OC

Universal Adaptive Proximal Gradient Methods via Gradient Mapping Accumulation

通过梯度映射累积实现通用自适应近端梯度方法

Zimeng Wang, Alp Yurtsever

AI总结 本文提出了一种自适应近端梯度方法,通过累积历史梯度映射范数实现自适应步长,无需修改问题参数即可在非凸光滑、凸非光滑或凸光滑三类问题中收敛,且在随机设置中有效控制噪声影响。

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AI中文摘要

我们提出了一种自适应近端梯度方法,用于最小化两个函数之和,其中一个是简单凸函数,而另一个属于非凸光滑、凸非光滑或凸光滑三类之一。该方法的关键特征是自适应步长,其分母累积历史梯度映射范数。在不修改或了解问题参数的情况下,该方法在所有三类问题中收敛,假设为温和的有界迭代和有界方差,收敛率与近端梯度方法在对数因子范围内相同,适用于确定性和随机设置。对于凸情况,我们进一步提出加速变体。它在非光滑情况下保持相似的近最优收敛率,并在光滑情况下达到改进的收敛率,即~O(1/t² + σ/√t),在对数因子范围内最优。值得注意的是,我们开发了新的技术来控制随机噪声的影响,这些技术适用于所有三类问题在随机设置中,并使分析简化。

英文摘要

We propose an adaptive proximal gradient method for minimizing the sum of two functions, where one is a simple convex function, and the other belongs to one of the three classes: nonconvex smooth, convex nonsmooth, or convex smooth. The key feature of the method is an adaptive step size that accumulates historical gradient mapping norms in the denominator. Without any modification or knowledge of problem parameters, the method converges across all three problem classes under mild bounded-iterates and bounded-variance assumptions, with rates matching those of the proximal gradient method up to logarithmic factors, in both deterministic and stochastic settings. For the convex setting, we further propose an accelerated variant. It retains a similar near-optimal convergence rate for the nonsmooth case and achieves an improved rate of order $\widetilde{O}\big(1/t^2 + σ/\sqrt{t}\big)$ for the smooth case, which is optimal up to logarithmic factors. Notably, we develop new techniques for controlling the effect of stochastic noise, which are applicable across all three problem classes in the stochastic setting and enable simplified analysis.

2605.05943 2026-05-08 math.AG

A two-step approach to Chow quotients

楚 quotient 的两步方法

Luis E. Solá Conde, Gianluca Occhetta

AI总结 本文提出通过投影托里克品种和其有理数自同构群来编码楚 quotient 的几何结构,并应用于某些特定的有理数 homogeneous 变形。

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AI中文摘要

项目性变种对复托里组作用的楚 quotient 被发现具有非常复杂的几何结构,即使在简单变种如有理数 homogeneous 变种的情况下也是如此。本文提出一种方法,将楚 quotient 的几何结构编码在投影托里克品种和其有理数 birational 自同构群的有限子群中。然后,我们展示了如何在某些特定的有理数 homogeneous 变种情况下应用我们的策略。

英文摘要

The Chow quotient of a projective variety by the action of a complex torus is known to have a very complicated geometry, even in the case of simple varieties, such as rational homogeneous varieties. In this paper we propose an approach in which the geometry of the Chow quotient is encoded in a projective toric variety and a finite subgroup of its birational automorphisms. We then illustrate how to apply our strategy in the case of some particular rational homogeneous varieties.

2605.05939 2026-05-08 math.DS

Bifurcations of grazing loops of arbitrary tangent multiplicity in piecewise-smooth systems

分段光滑系统中任意切乘数的 grazing 循环 分支

Xingwu Chen, Zhihao Fang, Tao Li

AI总结 研究分段光滑系统中 grazing 循环在任意切乘数下的分支特性,提出新的函数扰动方法和局部化技术,建立切乘数与极限环、滑动环数量的关系。

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AI中文摘要

在分段光滑微分系统中,当子系统的超曲面极限环与切换流形在切点处 grazing 时,其结构稳定性会丧失。此类循环称为 grazing 循环,本文研究其在任意切乘数下的分支问题。对于低切乘数情况,通过双参数函数扰动可全面捕捉复发现象,但高切乘数情况下参数失效,无法定义 Poincaré 返回映射。为此,本文构造函数扰动并提出局部化方法,使两种复发等价,并最终建立切乘数与穿越极限环、滑动环数量及滑动环上切点数的定量关系。

英文摘要

In piecewise-smooth differential systems, a hyperbolic limit cycle of a subsystem loses its structural stability if it grazes the switching manifold at a tangent point. Such a cycle is called a grazing loop and in this paper we investigate its bifurcations for arbitrary tangent multiplicity. For the low-multiplicity tangency, the recurrences are comprehensively captured by a functional perturbation with two parameters in previous publications, where the parameters characterize the recurrences near the tangent point and the limit cycle respectively. However, for high-multiplicity tangency, these parameters fail to capture the recurrences and thus, Poincare return maps can not be defined as usual. To address these challenges, we construct a functional perturbation with functions to clarify the recurrences and simultaneously, propose a localization method to make these two recurrences equivalent. We finally establish a quantitative relationship between the multiplicity of tangency and the numbers of crossing limit cycles, sliding loops bifurcating from the grazing loop and the number of tangent points on these sliding loops.

2605.05937 2026-05-08 astro-ph.GA

The multiple corrugations in the Galactic disk derived from the LAMOST and Gaia survey data

从LAMOST和Gaia调查数据中推导银河盘中的多重沟槽

Jifei Wang, Zhuohan Li, Chengdong Li, Yuqin Chen, Chengqun Yang, Zixi Guo, Zhou Fan, Hongrui Gu, Maoli Bu

AI总结 研究通过分析LAMOST和Gaia数据,揭示银河盘内外层的过渡特征,并利用简化模型解释径向沟槽对观测到的运动学特征的可能物理解释。

Comments Published in Astronomy and Astrophysics

Journal ref A&A, 709, A65 (2026)

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AI中文摘要

大规模光谱和视差巡天揭示了银河系盘中的复杂波状特征,暗示其运动学和化学结构受时间依赖扰动塑造。最近研究发现Rg-Vphi-VR空间中存在振荡模式,提示外盘可能存在结构转变。本文旨在表征内盘与外盘之间的过渡,并探讨径向沟槽是否能解释观测到的特征。通过分析LAMOST DR8和Gaia DR3的两组恒星样本,结合空间、运动学和化学诊断。构建了一个由两个反向传播径向波组成的简化沟槽模型,并拟合观测到的VR模式。进一步通过N体模拟验证模型。LAMOST和Gaia样本均再现了Rg-Vphi-VR平面中已报告的波状模式。通过旋转速度和金属度的变化,明确识别出内盘与外盘之间的过渡。沟槽模型自然再现了VR随银心距的周期性变化,两种传播模式的叠加在观测和模拟中均产生相似的振荡模式。模型表明,径向沟槽可为观测到的运动学特征提供合理解释。结果突显了银河系盘的复杂多扰动性质,并激励进一步利用即将到来的巡天进行研究。

英文摘要

Large spectroscopic and astrometric surveys have revealed complex wave-like features in the Milky Way disk, suggesting that its kinematic and chemical structures are shaped by time-dependent perturbations. Recent studies have reported oscillatory patterns in the Rg-Vphi-VR space, hinting at a possible structural transition in the outer disk. We aim to characterise the transition between the inner and outer Galactic thin disk and to investigate whether radial corrugations can provide a plausible physical interpretation of the observed features. We analysed two large stellar samples from LAMOST DR8 and Gaia DR3, combining spatial, kinematic, and chemical diagnostics. A simplified corrugation model consisting of two radial waves propagating in opposite directions was constructed and fitted to the observed VR pattern. We further validated the model using N-body simulations. Both LAMOST and Gaia samples reproduce the previously reported wave-like pattern in the Rg-Vphi-VR plane. We identify a clear transition between the inner and outer disks via the variations in rotational velocity and metallicities. The corrugation model naturally reproduces the periodic variation of VR with galactocentric radius, and the superposition of the inward and outward propagating modes gives rise to a comparable oscillatory pattern in both observations and simulations. Our modelling suggests that radial corrugations can provide a plausible interpretation of the observed kinematic signatures. The results highlight the complex, multi-perturber nature of the Galactic disk and motivate further investigation with upcoming surveys.

2605.05934 2026-05-08 cond-mat.stat-mech physics.chem-ph

Emergent conserved quantities via irreversibility

通过不可逆性涌现守恒量

Alex Blokhuis, Martijn van Kuppeveld, Daan van de Weem, Robert Pollice

AI总结 本文研究了不可逆反应如何导致CRN和马尔可夫链中涌现的守恒律和断裂循环,提出通过'共生产指数'描述线性依赖电流,解决了非整数守恒律的困境。

Comments 17 pages (5 main), 4 figures (2 main)

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AI中文摘要

守恒量在物理模型推断中起着越来越重要的作用。最近,在这一背景下发现了新的守恒量,但目前缺乏解释。本文表明,CRN和马尔可夫链中的不可逆反应会导致涌现的守恒定律和断裂循环。线性相关的电流——由“共生产指数”表征——由于不可逆反应而产生。我们推导出一个定律,将守恒量、断裂循环和共生产联系起来。这解决了最近由机器发现的非整数守恒律所提出的问题。我们的发现为CRN和马尔可夫链广泛使用的指数定律引入了之前忽视的扩展,该定律低估了守恒定律。这为基于守恒定律的模型推断和分析提供了新的工具和即时应用。

英文摘要

Conserved quantities increasingly underpin the inference of physical models. Recently new conserved quantities have been found in this context, that currently lack an interpretation. Here, we show that irreversible reactions in CRNs and Markov Chains lead to emergent conservation laws and broken cycles. Linearly dependent currents - characterized by the "co-production index" - arise due to irreversible reactions. We derive a law relating conserved quantities, broken cycles, and co-production. This resolves a recent conundrum posed by a machine-discovered candidate for a non-integer conservation law. Our findings introduce heretofore overlooked extensions to a widely used index law for CRNs and Markov Chains that undercounts conservation laws. This furnishes new tools and immediate applications for the inference and analysis of models based on conservation laws.

2605.05932 2026-05-08 eess.SY cs.SY

Consideration of Control-Loop Interaction in Transient Stability of Grid-Following Inverters using Bandwidth Separation Method

基于带宽分离法的电网跟踪逆变器暂态稳定性的控制回路交互考虑

Yifan Zhang, Yunjie Gu, Yue Zhu, Yitong Li, Hsiao-Dong Chiang, Timothy C. Green

AI总结 本文研究电网跟踪逆变器的暂态稳定性,提出带宽分离法分析PLL与DVC的交互影响,揭示电压不稳定是暂态不稳定的根源,并通过实验验证了PLL和DVC带宽配置对系统稳定性的影响。

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AI中文摘要

电网跟踪逆变器已被广泛应用于可再生能源并网,确保其小扰动和大扰动稳定性对现代电力系统至关重要。其大扰动稳定性分析具有挑战性,因为相位锁定环(PLL)必须与各种外环控制器保持同步。简单假设外环控制器为理想化的情况不足,必须考虑PLL的非线性动态与DC链接电压控制(DVC)动态以及存在时的交流端电压控制(TVC)动态的相互作用。本文提出了一种渐近分析方法,称为带宽分离法。该方法在存在充分带宽分离时能够简化并降低原始微分方程的阶数。通过该方法,明确表征了DVC与PLL的相互作用,揭示这种相互作用会降低系统稳定性并缩小稳定性区域。分析还表明,电压不稳定,而非PLL失同步本身,往往是暂态不稳定的根本原因。在各种电网故障条件下,确定了PLL和DVC的最佳带宽配置:较大的PLL带宽提高了对相位跳跃故障的韧性,而较大的DVC带宽增强了对功率波动的容忍度。此外,分析了TVC回路的影响,表明高TVC带宽可以缓解PLL-DVC相互作用的破坏性影响,并进一步提高暂态稳定性。所有分析发现均通过硬件在环(HIL)实验验证。

英文摘要

Grid-following inverters have been widely adopted as a grid interface for renewable energy, and ensuring their small-signal and large-signal stability is critical to modern power systems. Their large-signal, or transient, stability is a significant challenge to analyze because of the interaction of the phase-locked loop (PLL), which must maintain synchronism with various outer-loop controllers. Simple analysis in which outer-loop controllers are idealized is insufficient, and the interactions between the nonlinear dynamics of the PLL and the dynamics of the DC-link voltage control (DVC), as well as the AC terminal voltage control (TVC) when present, must be considered. An asymptotic analysis approach, termed the bandwidth separation method, is proposed. This method enables simplification and order reduction of the original differential equations when sufficient bandwidth separation exists. Through this method, the interaction between the DVC and PLL is explicitly characterized, revealing that such interaction degrades system stability and shrinks the stability region. The analysis also indicates that voltage instability, rather than PLL loss of synchronization alone, is often the root cause of transient instability. Optimal bandwidth configurations for the PLL and DVC are identified under various grid fault conditions: a larger PLL bandwidth improves resilience to phase-jump faults, while a larger DVC bandwidth enhances tolerance to power fluctuations. In addition, the influence of the TVC loop is analyzed, showing that a high TVC bandwidth can mitigate the destabilizing effects of PLL-DVC interaction and further improve transient stability. All analytical findings are validated through hardware-in-the-loop (HIL) experiments.

2605.05930 2026-05-08 stat.ME

Toward design-based inference for data integration

迈向基于设计的推断用于数据整合

Andrius Čiginas, Ieva Burakauskaitė, Jae Kwang Kim

AI总结 本文提出基于设计的推断方法,用于整合非概率样本,开发两种回归估计器,并在不同假设下提供一致性和优化性。

Comments 31 pages, 6 figures, 7 tables

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AI中文摘要

将非概率样本整合到有限总体推断中通常需要在缺失-at-random(MAR)假设下建模未知的选择概率,这难以验证。本文提出一种基于设计的替代方法,将非概率样本视为完全观测的确定 stratum,仅从互补的 previously 未采样单元中抽取概率样本。在这一顺序框架中,开发了两种广义回归估计器:一种在互补 stratum 中分别拟合结果模型,另一种合并两个样本;做出两个不同的贡献。首先,这两种估计器都是设计一致的,并且允许一致的方差估计器,无需对非概率选择机制做任何假设,包括在非缺失-at-random(NMAR)选择下。其次,在一个工作超总体模型下,试点非概率样本可用于构造第二阶段的 inclusion 概率,以实现 Isaki-Fuller 渐近最优性;这一最优性声明依赖于比 MAR 更严格的假设,但其失败不会影响上述一致性结果。提出了一种用于系数同质性的诊断测试以指导两种估计器的选择。模拟显示,顺序估计器在 MAR 和 NMAR 下基本无偏,而倾向调整的竞争对手在 NMAR 下可能严重偏倚。两个来自立陶宛官方统计数据的应用表明,当试点 stratum 和其互补部分强烈异质时,单独回归更优;当两个 stratum 相似时,合并回归提供小幅效率提升。

英文摘要

Integrating non-probability samples into finite-population inference typically requires modeling unknown selection probabilities under a missing-at-random (MAR) assumption that is difficult to verify. We propose a design-based alternative in which the non-probability sample is treated as a fully observed certainty stratum and a probability sample is drawn only from the complementary, previously unsampled units. Within this sequential framework, we develop two generalized regression estimators: one fitting the outcome model separately in the complementary stratum, the other pooling both samples; we make two distinct contributions. First, both estimators are design-consistent and admit consistent variance estimators with no assumption whatsoever on the non-probability selection mechanism, including under not-missing-at-random (NMAR) selection. Second, under a working superpopulation model that holds in both strata, the pilot non-probability sample can be used to construct second-stage inclusion probabilities that achieve Isaki-Fuller asymptotic optimality for the separate estimator; this optimality claim relies on assumptions strictly stronger than MAR, but its failure does not invalidate the consistency results above. A diagnostic test for coefficient homogeneity is proposed to guide the choice between the two estimators. Simulations confirm that the sequential estimators remain essentially unbiased under both MAR and NMAR, while propensity-adjusted competitors can be severely biased under NMAR. Two applications from Lithuanian official statistics illustrate that separate regression is preferable when the pilot stratum and its complement are strongly heterogeneous, whereas combined regression offers a modest efficiency gain when the two strata are similar.

2605.05926 2026-05-08 physics.optics

Narrowband-to-broadband switchable and polarization-insensitive terahertz metasurface absorber enabled by phase-change material

基于相变材料的窄带到宽带可切换且偏振不敏感的太赫兹元表面吸收体

S. Hadi Badri, M. M. Gilarlue, Sanam SaeidNahaei, Jong Su Kim

AI总结 本文提出一种基于vanadium dioxide的可切换带宽和偏振不敏感的太赫兹元表面吸收体,通过有限元模拟验证其性能,展示了通过控制相变材料实现带宽和吸收率调节的能力。

Journal ref Journal of Optics 24.2 (2022): 025101

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AI中文摘要

一种具有可控和可切换带宽且对偏振不敏感的太赫兹吸收体具有很大研究价值。本文提出并演示了一种基于vanadium dioxide(VO2)相变材料的元表面吸收体,通过有限元方法模拟验证其性能。该元表面吸收体由混合十字分形作为谐振器,通过聚酰亚胺间隔层与金地平面分离。通过将VO2片连接到金的一阶十字分形,将其转换为三阶十字分形,实现了从窄带到宽带吸收体的切换。在VO2的绝缘相中,主要窄带吸收发生在6.05 THz频率,吸收率为0.99,全宽半高(FWHM)为0.35 THz。当VO2从绝缘体转变为金属体时,该元表面实现宽带吸收,FWHM为6.17 THz。模拟表明,通过控制VO2的部分相变,可以调节吸收体的带宽和吸收率。此外,由于对称性,设计的吸收体对偏振不敏感,并且在很宽的入射角范围内表现良好。在VO2的金属态中,吸收体在3.57-8.45 THz频率范围内,入射角达65°时,吸收率超过0.5。

英文摘要

A terahertz absorber with controllable and switchable bandwidth and insensitive to polarization is of great interest. Here, we propose and demonstrate a metasurface absorber with switchable bandwidth based on a phase-change material of vanadium dioxide (VO2) and verify its performance by the finite element method simulations. The metasurface absorber is composed of a hybrid cross fractal as a resonator separated from a gold ground-plane by a polyimide spacer. Switching from narrowband to broadband absorber is achieved via connecting VO2 patches to the gold first-order cross fractal converting the resonator to a third-order cross fractal. In the insulator phase of VO2, the main narrowband absorption occurs at the frequency of 6.05 THz with a 0.99 absorption and a full-width half-maximum (FWHM) of 0.35 THz. Upon insulator-to-metal transition of VO2, the metasurface achieves a broadband absorption with the FWHM of 6.17 THz. The simulations indicate that by controlling the partial phase-transition of VO2, we can tune the bandwidth and absorption level of the absorber. Moreover, the designed absorber is insensitive to polarization due to symmetry and works well for a very wide range of incident angles. In the metallic state of VO2, the absorber has an absorption exceeding 0.5 in the 3.57-8.45 THz frequency range with incident angles up to 65°.

2605.05924 2026-05-08 physics.med-ph

Injectable Thermochemical Micro-Explosion for Prompt Thrombolysis via Liquid Alkali Metal

可注射热化学微爆炸用于通过液态碱金属实现快速血栓溶解

Xin Liao, Yi Hou, Jie Zhang, Bo Wang, Minghui Guo, Hua Qu, Wei Rao, Jing Liu

AI总结 本研究提出一种通过可注射液态碱金属与硅油复合物实现快速、高效且安全的血栓溶解方法,其通过机械微爆炸、碱性蚀刻和热溶解三重机制有效溶解血栓,相较于现有药物具有更高的溶解效率和无出血风险。

Comments 25 pages, 6 figures. This article was originally submitted to Advanced Materials in September 2025 and has been reviewed twice and then recommended to Advanced Science for publication by offering no further need of external peer review and has been with the journal with all updated documents since January 23, 2026

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AI中文摘要

血栓性血管疾病导致全球显著死亡,但现有治疗策略面临出血风险、效率低下和操作复杂等挑战。本文报道了一种通过可注射液态碱金属(LAM)封装在二甲基硅油(LAM@油)中的微爆炸热化学血栓溶解(METCT)疗法,可在超快时间(<90秒)内实现快速、高效且安全的血管再通。该LAM@油系统通过机械微爆炸力、高度局部放热化学反应导致的碱性蚀刻以及高温介导的热溶解三重作用机制有效破坏血栓组织。血栓溶解完成后,非毒性的反应产物(钠和钾离子)表现出生理上生物相容且可代谢的效果。关键的是,LAM@油相比现有临床可用的血栓溶解药物具有显著更高的溶解效率(LAM@油残留血栓面积百分比10.87%±7.16% vs. urokinase 80.86%±13.32%),无相关出血风险。该策略提供了一种无副产物、成本效益高且高效替代传统血栓溶解剂的方法,具有在急性血栓管理中临床转化的巨大潜力。

英文摘要

Thrombotic vascular diseases contribute to significant global mortality, yet current therapeutic strategies face persistent challenges including bleeding risks, suboptimal efficiency, and procedural complexity. Here, we report a micro-explosive thermochemical thrombolysis (METCT) therapy via injectable liquid alkali metal (LAM) encapsulated in dimethyl silicone (LAM@oil), which enables prompt, efficient and safe vascular recanalization within an ultrafast timeframe (< 90 seconds). This LAM@oil system effectively disrupts thrombus tissue through a synergistic triple-action mechanism: Mechanical micro-explosions forces, alkaline ablation due to highly localized exothermic chemical reactions, and thermal thrombolysis mediated by elevated temperature. Upon thrombolysis completion, the non-toxic reaction byproducts (sodium and potassium ions) exhibit physiologically biocompatible and metabolizable effects. Critically, the LAM@oil demonstrates significantly higher thrombolytic efficacy compared to clinically available thrombolytic drugs (residual thrombus area percent 10.87%+-7.16% for LAM@oil vs. 80.86%+-13.32% for urokinase), with no associated bleeding risks. This strategy opens a byproduct-free, cost-effective, and high-efficiency alternative to conventional thrombolytics, holding big potential for clinical translation in acute thrombosis management.

2605.05923 2026-05-08 stat.ME

Joint modelling of time-dependent biomarker variability and time-to-event outcomes, a two-step approach

时间依赖性生物标志物变异与时间到事件结果的联合建模:一种两步方法

Felix Boakye Oppong, Dimitris Rizopoulos, Thierry Gorlia, Nicole Erler

AI总结 本文提出一种两步方法,将生物标志物变异纳入联合模型中,通过残差分析和标准联合模型结合,评估变异与生存的关系,适用于多生物标志物和现有软件。

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AI中文摘要

越来越多的证据表明,纵向生物标志物的变异,除了其均值轨迹外,对时间到事件结果具有预测信息。然而,标准联合模型通常仅捕捉生物标志物过程的预期值,假设残差变异在个体和时间上恒定。完全联合扩展模型可以建模个体内部变异,但计算成本高且需要专用软件。我们提出了一种灵活的两步方法,首先使用混合效应模型的残差(或其变换)推导出个体和时间特异的变异度量,然后将这些变异度量纳入标准联合模型中,以估计其与生存的关系。我们的方法还可同时处理多个生物标志物,并利用现有联合建模软件实现,无需定制扩展。通过模拟,我们展示了该方法在多种场景下对变异效应的合理性能。我们进一步利用纵向白血球计数数据展示了平均水平和变异性的血球标志物对总生存率的预测信息。

英文摘要

Increasing evidence suggests that variability in longitudinal biomarkers, in addition to their mean trajectory, carries prognostic information for time-to-event outcomes. However, standard joint models typically capture only the expected value of the biomarker process, assuming constant residual variability across individuals and time. Fully joint extensions that model within-subject variability exist but are computationally demanding and require dedicated software packages. We propose a flexible two-step approach for incorporating biomarker variability into joint models. First, residuals (or their transformations) from a mixed-effects model are used to derive subject- and time-specific measures of variability. Second, these variability measures are included in a standard joint model, allowing their association with survival to be estimated alongside the mean biomarker trajectory. Our approach can also accommodate multiple biomarkers simultaneously and is readily implemented using existing joint modeling software without custom extensions. Through simulations, we show that our method provides reasonable performance for variability effects across a range of scenarios. We further illustrate our approach using longitudinal data of white blood cell counts from a large phase III glioblastoma trial, demonstrating that both mean levels and variability of hematological markers carry prognostic information for overall survival.

2605.05919 2026-05-08 physics.soc-ph

Compound effects of traffic and climate on electric vehicle HVAC energy consumption: a spatiotemporal framework with city-level attribution

交通与气候对电动汽车HVAC能耗的复合影响:一种具有城市级归因的时空框架

Liang Zhang, Wei He

AI总结 本文提出一种时空框架,分析交通与气候对电动汽车HVAC能耗的复合影响,通过分解方法归因于温度和行程时间,揭示冬季舱内热管理的主要差异。

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AI中文摘要

现实中的电动汽车能耗可能偏离额定值20-40%,由环境温度、交通拥堵和路线特征驱动。现有研究将这些因素孤立或作为静态负载处理,未量化气候与交通共同变化对HVAC能耗的复合效应及路线级归因。本文开发了一个时空模拟框架,结合交通感知的驾驶速度、时间与地点特定的环境温度,以及基于物理的子模型(车厢HVAC、牵引、电池热管理),在路段层面进行耦合,配以基于回归的分解方法,将HVAC变化归因于温度和行程时间组件,按路线进行归因。通过在七个英国城市和八条曼彻斯特径向路线上的因子设计应用,框架显示总能耗在城市间变化14%,HVAC能耗最高达89%,表明冬季舱内热管理是主要差异因素。行程时间,由交通和道路类型决定,通常是HVAC变化的主要驱动因素:在伦敦,超过平均HVAC能耗的83%可归因于拥堵延长的行程时间而非温度。分解结果提供了一个闭合形式的HVAC模型,从三个输入(环境温度、平均速度、行程距离)中获得,具有物理可解释的系数,可通过三次系数重新拟合轻松转移到其他车辆或地区。电动汽车续航变化显著受交通和道路网络特征影响,对路线规划、基础设施设计和能源公平性有影响。

英文摘要

Real-world electric vehicle (EV) energy consumption can deviate by 20-40% from rated values, driven by ambient temperature, traffic congestion, and route characteristics. Existing studies treat these factors in isolation or as static loads, leaving the compound effect of co-varying climate and traffic on HVAC energy unquantified and per-route attribution unavailable. We develop a spatiotemporal simulation framework that couples traffic-aware driving speed, time- and location-specific ambient temperature, and physics-based submodels (cabin HVAC, traction, battery thermal management) at the segment level, paired with a regression-based decomposition that attributes HVAC variability to temperature and trip-duration components on a per-route basis. Applied through a factorial design across seven UK cities and eight radial routes from Manchester, the framework shows total energy varying by 14\% across cities while HVAC energy varies by up to 89\%, making cabin thermal management the primary differentiator under winter conditions. Trip duration, set by traffic and road type, is frequently the dominant driver of HVAC variability: in London, 83\% of above-average HVAC energy is attributable to congestion-extended trip time rather than to temperature. The decomposition yields a closed-form HVAC model from three inputs (ambient temperature, average speed, trip distance), with physically interpretable coefficients and straightforward transfer to other vehicles or regions through three coefficient re-fits. EV range variability is substantially shaped by traffic and road-network characteristics, with implications for route planning, infrastructure design, and energy equity.

2605.05918 2026-05-08 physics.optics

Thermally reconfigurable extraordinary terahertz transmission using vanadium dioxide

基于氧化钒的热控可重构非凡太赫兹传输

S. Hadi Badri, Hadi Soofi, Sanam Saeidnahaei S

AI总结 研究通过氧化钒相变材料实现可重构非凡太赫兹传输,利用亚波长孔洞结构调控传输窗口,实现红移或蓝移,并展示其在太赫兹调制器和可重构滤波器中的应用潜力。

Journal ref Journal of the Optical Society of America B 39.6 (2022): 1614-1621

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AI中文摘要

我们通过数值模拟展示了基于氧化钒(VO2)相变材料的可重构非凡太赫兹传输。所提出的混合超表面由在金膜上排列的亚波长孔洞组成。孔洞部分填充环形VO2和金盘以控制有效孔洞面积和孔洞内的模式。通过切换VO2的绝缘体和金属相可方便地移动传输窗口。我们提出了两种设计,分别实现非凡太赫兹传输的红移或蓝移。在相变从绝缘体到金属相时,第一种设计的传输峰值从1.02 THz红移至0.82 THz,而第二种设计的传输峰值从0.71 THz蓝移至0.77 THz。此外,通过控制VO2的部分相变可调节传输水平和共振频率。所提出结构的潜在应用包括太赫兹调制器和可重构滤波器。

英文摘要

We numerically demonstrate a reconfigurable extraordinary terahertz transmission based on a phase-change material of vanadium dioxide (VO2). The proposed hybrid metasurface is composed of an array of subwavelength apertures perforated on a gold film. The holes are partially filled with annular VO2 and gold disks to control the effective aperture area and the modes inside the aperture. Switching between the insulator and the metallic phase of VO2 provides a convenient way to shift the transmission window. We present two designs offering redshift or blueshift of the extraordinary terahertz transmission. Upon phase transition from the insulator to the metallic phase, in the first design, the transmission peak redshifts from 1.02 to 0.82 THz while in the second design the transmission peak blueshifts from 0.71 to 0.77 THz. Furthermore, the transmission level and resonance frequency can be modulated by controlling the partial phase transition of the VO2. The potential applications for the proposed structures are terahertz modulators and reconfigurable filters.

2605.05917 2026-05-08 cs.CG

A Constant-Factor Approximation for Continuous Dynamic Time Warping in 2D

二维连续动态时间变形的常数因子近似算法

Kevin Buchin, Maike Buchin, Jan Erik Swiadek, Sampson Wong

AI总结 本文提出了一种在二维空间中计算连续动态时间变形的常数因子近似算法,时间复杂度为O(n^5),并扩展到所有二维多边形范数,实现了(5+ε)-近似算法。

Comments Appearing in ICALP 2026

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AI中文摘要

连续动态时间变形(CDTW)是一种用于多边形曲线的鲁棒相似性度量,已应用于多种领域。尽管其实际应用广泛,但计算其算法复杂性,特别是在需要精确解或强近似保证的情况下,知之甚少。本文通过引入一个5-近似算法,运行时间为O(n^5)(基于1-范数),填补了这一空白。这是首个具有多项式运行时间的二维CDTW常数因子近似算法。我们扩展了该算法到所有R^2上的多边形范数,并利用此结果在任意固定范数下实现CDTW的(5+ε)-近似算法,时间复杂度为O(n^5/ε^{1/2})。后者特别包括通常的欧几里得2-范数。

英文摘要

Continuous Dynamic Time Warping (CDTW) is a robust similarity measure for polygonal curves that has recently found a variety of applications. Despite its practical use, not much is known about the algorithmic complexity of computing it in 2D, especially when one requires either an exact solution or strong approximation guarantees. We fill this gap by introducing a $5$-approximation algorithm with running time $O(n^5)$ under the 1-norm. This is the first constant-factor approximation for 2D CDTW with polynomial running time. We extend our algorithm to all polygonal norms on $\mathbb{R}^2$, which we subsequently use in order to achieve a $(5+\varepsilon)$-approximation with time complexity $O(n^5 / \varepsilon^{1/2})$ for CDTW in 2D under any fixed norm. The latter result in particular includes the usual Euclidean 2-norm.

2605.05915 2026-05-08 cond-mat.stat-mech

Lack of self-averaging of the critical internal energy in a weakly-disordered Baxter model

Baxter模型中临界内能的自平均性缺失

Ramgopal Agrawal, Victor Dotsenko, Maxym Dudka, Marco Picco, Enzo Marinari, Gleb Oshanin

AI总结 研究Baxter模型中临界内能的两个矩随系统尺寸变化,发现其相对方差随系统尺寸增大而增加,表明临界内能和自由能缺乏自平均性。

Comments 24 pages, 8 figures

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AI中文摘要

我们研究了弱 disorder 的二维Baxter八顶点模型中临界内能E的前两个矩随系统尺寸L的变化,评估在伪临界点。 disorder 通过等效的纯八顶点模型表示为两个铁磁Ising模型的耦合,通过四自旋相互作用强度g0连接,其中Ising耦合包括均匀铁磁部分J>0以及弱高斯空间 disorder。在临界区域,模型用相互作用的Grassmann-Majorana旋量场和四次相互作用来描述,并利用复制和重整化群方法分析,对于小正g0。我们还进行了广泛的数值模拟测量临界内能。我们的结果表明,其相对方差随L增加而增加,并在L→∞时接近有限常数,无论g0的正负。因此,波动在g0正负时都相关,表明临界内能和自由能缺乏自平均性。因此,可靠估计这些量需要在许多 disorder 实现上平均。此外,我们数值确认了关于无序Ising模型中临界内能自平均性缺失的先前预测。

英文摘要

We investigate the first two moments of the critical internal energy $E$ in a weakly disordered two-dimensional Baxter eight-vertex model as a function of the system size $L$, evaluated at the pseudo-critical point. Disorder is introduced via an equivalent representation of the pure eight-vertex model in terms of two ferromagnetic Ising models coupled by a four-spin interaction of strength $g_0$, where the Ising couplings consist of a uniform ferromagnetic part $J>0$ supplemented by weak Gaussian spatial disorder. In the critical regime, the model is formulated in terms of interacting Grassmann-Majorana spinor fields with quartic interactions and analyzed, for small positive $g_0$, using a combination of replica and renormalization-group methods. We also run extensive numerical simulations measuring the critical internal energy. Our results show that its relative variance increases with $L$ and approaches a finite constant as $L \to \infty$ for both $\pm g_0$. Hence, fluctuations remain relevant independently of the sign of $g_0$ (and thus of the specific-heat exponent), implying a lack of self-averaging of both the critical internal energy and the free energy. Consequently, reliable estimates of these quantities require averaging over many disorder realizations. In addition, we numerically confirm earlier predictions concerning the absence of self-averaging of the critical internal energy in the disordered Ising model.

2605.05907 2026-05-08 q-bio.NC

Decoding Alignment without Encoding Alignment: A critique of similarity analysis in neuroscience

无需编码对齐的解码对齐:对神经科学中相似性分析的批评

Johannes Bertram, Luciano Dyballa, T. Anderson Keller, Savik Kinger, Steven W. Zucker

AI总结 本文指出解码相似性分析的局限性,揭示解码表示可能受少量神经元影响,提出编码 manifold 作为对比神经系统的补充工具。

Comments 40 pages, 27 figures

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AI中文摘要

解码方法在神经科学和机器学习中被广泛用于比较不同神经系统(如不同脑区、生物体和深度学习模型)的刺激表示。流行方法包括解码(感知)流形和对齐度量,如表征相似性分析(RSA)和动态相似性分析(DSA),其中解码表示的相似性被解释为相似计算的证据。本文展示了一种根本性弱点:当表示几何可能由少量神经元塑造时,假设表示几何代表整个神经群体是误导的。我们表明互补的编码范式直接解决了这一问题:它描述神经元如何在响应数据集时全局组织,提供关于解码表示如何在群体内实现的见解。我们通过生物系统和深度学习模型的实验表明:(i) 出人意料的是,相似的解码行为和高表示对齐可能来自小而不具代表性的神经元子群;(ii) 对齐度量对编码流形拓扑(功能在神经元上的分布)不敏感,尽管这是生物系统区分的关键特征。一个受控的MNIST实验提供了因果证据:即使通过训练损失操纵编码拓扑,解码度量保持不变。总体而言,解码行为的相似性,如通过经典对齐度量测量,不意味着功能或计算的相似性,这促使使用编码流形作为比较神经系统的补充工具。

英文摘要

Decoding approaches are widely used in neuroscience and machine learning to compare stimulus representations across neural systems, such as different brain regions, organisms, and deep learning models. Popular methods include decoding (perceptual) manifolds and alignment metrics such as Representational Similarity Analysis (RSA) and Dynamic Similarity Analysis (DSA), where similarity in decoding representations is interpreted as evidence for similar computation. This paper demonstrates a fundamental weakness behind this approach: it is misleading to assume that representational geometry is representative of a neuronal population as a whole, when such representations may actually be shaped by a very small subset of neurons. We show that the complementary encoding paradigm addresses this issue directly: it characterizes how neurons are organized globally in terms of their responses to a set of data, providing insight into how the decoding representation is implemented by neurons within a population. We demonstrate across experiments in biological systems and deep learning models that (i) surprisingly, similar decoding behavior and high representational alignment can arise from small, non-representative subpopulations of neurons; and critically, (ii) alignment metrics are insensitive to encoding manifold topology (how function is distributed across neurons), despite this being a key signature of differentiation across biological systems. A controlled MNIST experiment provides causal evidence: decoding metrics remain unchanged even when encoding topology is causally manipulated via the training loss. Overall, similarity in decoding behavior, as measured by classic alignment metrics, does not imply similarity in function or computation, motivating the use of encoding manifolds as a complementary tool for comparing neural systems.

2605.05904 2026-05-08 math.PR

Schrödinger's problem with constraints

带有约束的薛定谔问题

Beatrice Acciaio, Umut Çetin

AI总结 本文研究了更广泛的桥梁类,用于考虑更一般的均衡模型,如包含交易成本和违约风险的模型,并证明这些桥梁是薛定谔型问题的解。

详情
AI中文摘要

受静态私人信号与布朗桥之间的联系启发,我们研究了更广泛的桥梁类,允许考虑更一般的均衡模型,例如包含交易成本和违约风险的模型。我们证明这些桥梁是薛定谔型问题的解。利用这一联系,我们得出在包含交易成本的模型中的均衡收敛到经典凯利模型中的均衡。

英文摘要

Motivated by the connection between the Kyle equilibrium with static private signal and the Brownian bridge, we study a much broader class of bridges that allow one to consider more general equilibrium models, for example ones including trading costs and default risk. We show that such bridges are solutions to problems of the Schrödinger-type. Leveraging this connection, we obtain that the equilibria in models with trading costs converge to equilibria in the classical Kyle model.

2605.05903 2026-05-08 hep-th gr-qc

Trace anomaly, effective approach, and gravitational potential

追迹异常、有效方法和引力势

Riccardo Fecchio, Ilya L. Shapiro

AI总结 本文探讨了由共形物质场量子效应引起的牛顿势修正,比较了有效量子引力方法和基于追迹异常的方法,分析了两种方法在计算引力势修正时的差异及解决途径。

Comments 18 pages + Appendix

详情
AI中文摘要

我们探讨并讨论了由共形物质场的量子效应引起的牛顿势的修正。在这一特殊情况下,可以比较不同的方法,包括有效量子引力方法和基于追迹异常的方法。本文的主要焦点是比较这两种方法。使用由异常引起的引力有效作用需要固定量子真空态,类似于黑洞蒸发的描述。在Boulware真空态中,我们计算了由异常引起的应力张量和经典引力定律的一阶修正。通过这种方式得到的牛顿势的量子修正,与通过类似于有效量子引力方法计算的结果不同。要调和这两种方法以得到牛顿势的主导半经典修正,唯一的方法是修改Boulware真空态中能量动量张量平均值的渐近行为,这最近在文献中已有讨论。

英文摘要

We explore and discuss corrections to the Newton potential from the quantum effects of conformal matter fields. In this special case, one can compare different approaches, including that of effective quantum gravity and another, based on the conformal (trace) anomaly. The comparison of these two methods is the main focus in the present work. Using the anomaly-induced effective action of gravity requires fixing the quantum vacuum state, similar to what is done in the description of black hole evaporation. In the Boulware vacuum state, we compute the anomaly-induced stress tensor and the first-order correction to the classical gravitational law. The quantum correction to the Newton's potential derived in this way, differs from the result calculated in a way analogous to the effective approach to quantum gravity. The only way to reconcile the two approaches for deriving the leading semiclassical corrections to Newtonian potential is to modify the asymptotic behavior of the average of the energy-momentum tensor in the Boulware vacuum state, as has been recently discussed in the literature.