《自然》（20260820出版）一周论文导读

 

编译 | 未玖

Nature, 20 August 2026, Volume 656, Issue 8128

《自然》，2026年8月20日，第656卷，8128期

物理学Physics

Ubiquitous Kelvin–Helmholtz instabilities driving plasma mixing on the Sun

普遍存在的开尔文—亥姆霍兹不稳定性驱动太阳等离子体混合

▲ 作者：David Kuridze, Friedrich W?ger, Michiel van Noort, Matthias Rempel, Robert Cameron, Thomas Rimmele, et al.

▲链接：

https://www.nature.com/articles/s41586-026-10871-3

▲摘要：

太阳光球层中磁场与湍流对流之间的相互作用，驱动其磁化大气的动力学、演化和结构形成。现代观测的空间分辨率水平通常很难探测到这种相互作用。

研究组报道了利用世界首台4米级太阳望远镜，即美国国家科学基金会的丹尼尔·K·伊诺耶太阳望远镜所获取的太阳光球层高空间分辨率观测结果。时序图像揭示了一个比以往观测更复杂、更动态的太阳场景。

研究组发现在磁通量集中区的边缘处普遍存在磁化开尔文—亥姆霍兹不稳定性，这为长期存在的理论预测提供了实验验证。太阳光球层中小尺度磁化开尔文—亥姆霍兹不稳定性的发现（可通过高分辨率数值模拟重现），对学界理解伴涡旋运动（或导致磁通量编织）磁场的产生与耗散过程具有深远意义。

研究结果印证了以下图像：在可见太阳表面之下的磁场聚集区互不连通，但它们却与太阳光球层中以亮斑和黑子孔形式显现的单片磁通区域相连。开尔文—亥姆霍兹不稳定性是磁流体动力学系统中传输质量、能量、动量和磁通量的高效机制，为理解诸如此次观测到的磁活动区过程提供了变革性见解。

▲ Abstract：

The interaction between the magnetic field and turbulent convection in the Sun’s photosphere drives the dynamics, evolution and structuring of its magnetized atmosphere. This interaction often takes place at or below the spatial resolution of modern-day observations. Here we report on high-spatial-resolution observations of the solar photosphere acquired using the world’s first 4-m class solar telescope, the US National Science Foundation’s Daniel K. Inouye Solar Telescope. Time sequence images reveal a far more complex and dynamic solar scene than previously observed. We identify ubiquitous magnetized Kelvin–Helmholtz instabilities at the edges of magnetic flux concentrations and provide experimental confirmation of a long-standing theoretical prediction. The discovery of small-scale magnetized Kelvin–Helmholtz instabilities in the solar photosphere, which can be reproduced by high-resolution numerical simulations, has far-reaching implications for our understanding of the creation and dissipation of magnetic fields exhibiting vortex motion, which can lead to flux braiding. Our results support the picture of disjoint magnetic field concentrations in layers below the visible solar surface that connect to monolithic flux regions visible as facular concentrations and pores in the solar photosphere. Kelvin–Helmholtz instabilities are an efficient mechanism for transporting mass, energy, momentum and magnetic flux in magnetohydrodynamic systems, and they offer transformative insights into processes in magnetically active regions such as the one observed here.

材料科学Materials Science

Superconducting 2D cuprate with a single CuO₂ plane

具有单CuO₂平面的超导二维铜酸盐

▲ 作者：Hengsheng Luo, Dongjoon Song, Yijun Yu, Liguo Ma, Peng Cai, Ruidan Zhong, et al.

▲链接：

https://www.nature.com/articles/s41586-026-10857-1

▲摘要：

原子级薄的范德华晶体代表了二维（2D）极限下的理想材料体系。这种维度的降低通常会导致重要影响，石墨烯及其他可通过门控轻松调控的2D材料中所涌现的新物理现象便是最佳例证。将这种自上而下的制备方法推广至其他材料体系，蕴含着广阔机遇。近期实验表明，铜酸盐高温超导的关键物理特性仅需两个CuO2面即可承载。

研究组通过检测仅包含一个CuO₂平面的单层Bi₂Sr₂CuO_6+δ（Bi-2201），将降维推向了极致。在这个终极2D极限下，研究组观察到了显著的维度效应，表现为最佳超导转变温度降低约10%。此外，这一维度降低还带来了前所未有的可调性，即通过对单层样品进行精细控制氧化处理，研究组成功将Bi-2201的相图拓展至未知领域。

利用这种可调性，研究组发现当温度趋近于零时，在绝缘态与超导态之间会出现一个异常金属态。同时还观测到一种以发散临界指数为特征的异常标度行为。这些发现揭示了铜酸盐中超导体—绝缘体量子相变的本质。

▲ Abstract：

Atomically thin van der Waals crystals epitomize ideal material systems in the two-dimensional (2D) limit. This reduction in dimensionality often leads to important consequences, best exemplified by the emergence of new physics in graphene and other 2D materials that can be readily tuned by gating. Vast opportunities arise in extending this top-down approach to other material systems. Recent experiments have demonstrated that the essential physics of high-temperature superconductivity in cuprates is contained within just two CuO₂ planes. Here we push dimensionality reduction to the extreme by examining a single layer of Bi₂Sr₂CuO_6+δ (Bi-2201), which comprises only one CuO₂ plane. In this ultimate 2D limit, we observe a robust dimensionality effect that manifests as an approximately 10% reduction in the optimal superconducting transition temperature. Moreover, this reduction in dimensionality offers unprecedented tunability—we successfully extended the phase diagram of Bi-2201 into uncharted territories via finely controlled oxygenation of single-monolayer specimens. Leveraging this tunability, we discovered that an anomalous metal state emerges between the insulating and superconducting states as the temperature approaches zero. Concurrently, we observe an anomalous scaling behaviour characterized by a divergent critical exponent. These findings illuminate the nature of the superconductor-to-insulator quantum phase transition in cuprates.

Perovskite–organic tandem solar cells with a photo-transformable stabilizer

光转换稳定剂助力高效钙钛矿-有机叠层太阳能电池

▲ 作者：Ruihan Wu, Shucheng Qin, Tianwei Zou, Xin Jiang, Senyao Wang, Siyu Zhuang, et al.

▲链接：

https://www.nature.com/articles/s41586-026-10869-x

▲摘要：

宽禁带（WBG）混合卤化物钙钛矿具有高溴（Br）含量，用作钙钛矿—有机叠层太阳能电池（TSC）的前电池材料，但往往存在初始卤化物混合不均匀以及光致卤化物偏析的问题，限制了钙钛矿-有机TSC的性能。

研究组将一种光转换添加剂4-[3-(三氟甲基)-3H-二氮杂环丙烯-3-基]苄基铵盐（TDB）引入WBG钙钛矿前驱体溶液中，以建立一种两阶段策略来稳定混合卤化物相。在结晶过程中，TDB通过抑制富Br相的快速析出并加速退火过程中的卤化物混合，改善了初始卤化物的均匀性。

在运行光照条件下，TDB发生转化，形成一种对钙钛矿晶界表面具有更强吸附作用的新物种，抑制了与碘化物相关的缺陷形成，并抑制了缺陷辅助的载流子捕获和离子迁移，从而减缓了光致卤化物偏析。

具有代表性的WBG钙钛矿（带隙能量（Eg）=1.88 eV）太阳能电池实现了20.01%的功率转换效率（PCE），开路电压为1.42 V，填充因子为85.13%，且在光照下稳定性得到改善。

将该WBG钙钛矿太阳能电池集成到单片钙钛矿—有机TSC中，研究组获得了28.80%的PCE，经认证的稳态PCE为28.04%。该钙钛矿—有机TSC在ISOS-L-1标准协议下运行625小时后，仍保持其初始PCE的90%。

▲ Abstract：

Wide-bandgap (WBG) mixed-halide perovskites with high bromine (Br) content, which are used as the front-cell material in perovskite–organic tandem solar cells (TSCs), often exhibit initial halide-mixing inhomogeneity and light-induced halide segregation, limiting the performance of perovskite–organic TSCs. Here we introduce a photo-transformable additive, 4-[3-(trifluoromethyl)-3H-diazirin-3-yl]benzylammonium salt (TDB), into the WBG perovskite precursor solution to establish a two-stage strategy for stabilizing the mixed-halide phase. During crystallization, TDB improves the initial halide homogeneity by suppressing the rapid precipitation of the Br-rich phase and accelerating halide mixing upon annealing. During operational illumination, TDB undergoes transformation to form a new species with stronger adsorption on the perovskite grain-boundary surfaces, which inhibits the formation of iodide-related defects and suppresses defect-assisted carrier trapping and ion migration, thereby mitigating light-induced halide segregation. The representative WBG perovskite (bandgap energy （Eg）=1.88 eV solar cell had a power conversion efficiency (PCE) of 20.01%, with an open-circuit voltage of 1.42 V, a fill factor of 85.13% and improved stability under illumination. By integrating the WBG perovskite solar cell into a monolithic perovskite–organic TSC, we achieved a PCE of 28.80%, with a certified steady-state PCE of 28.04%. The perovskite–organic TSC retained 90% of its initial PCE after 625 h of operation under the ISOS-L-1 protocol.

化学Chemistry

Photocatalytic water splitting by 2D polymer with out-of-plane carrier flow

具有面外载流子流动的二维聚合物光催化水分解

▲ 作者：Hangyu Zhuzhang, Zhiyang Yu, Xiaocong Liang, Lihua Lin, Xianzhi Fu, Kazunari Domen, et al.

▲链接：

https://www.nature.com/articles/s41586-026-10866-0

▲摘要：

利用半导体颗粒进行太阳能驱动的水分解，为制氢提供了一条可持续路径。二维（2D）π共轭聚合物因其成本效益和光电可调性，已成为颇具前景的光催化剂。然而，聚合物中的光激发态在很大程度上局限于π共轭2D平面内，使得载流子容易发生复合。

尽管学界广泛通过调控电子结构来增强面内电荷分离，但长期实验仍持续暴露出量子效率的瓶颈。为了最大化电荷利用效率，主要挑战在于诱导面外载流子迁移，即促使载流子穿过范德华键合层进行流动。

研究组以聚合氮化碳晶体为模型体系，证明了通过在不同聚合物面封装纳米膜来施加横向或纵向内电场，可在长达约200 nm的惊人距离上激活面外载流子输运。横向和纵向电场分别将全分解水的表观量子效率提升至53.4%和82.1%。

该研究提出了一种新策略，实现了从本征2D限域激发态向动力学驱动的3D空间分离态的转变，为通过聚合物光催化最大化能量转换效率奠定了基础。

▲ Abstract：

Solar-driven water splitting with semiconductor particulates offers a sustainable pathway for hydrogen production. Two-dimensional (2D) π-conjugated polymers have emerged as promising photocatalysts owing to their cost effectiveness and optoelectronic tunability. However, photoexcited states in polymers are largely confined within π-conjugated 2D planes, making charge carriers vulnerable to recombination. Despite widespread modification of the electronic structure to enhance in-plane charge separation, long-term experimental efforts continue to highlight a persistent bottleneck in quantum efficiency. To maximize charge utilization efficiency, the main challenge lies in inducing out-of-plane carrier migration, namely, fostering carrier flow through van der Waals-bonded layers. Here, using polymeric carbon nitride crystals as model systems, we demonstrate that out-of-plane carrier transport can be activated over surprisingly long distances (about 200 nm) by applying lateral or vertical internal electric fields by means of encapsulating nanofilms on different polymer facets. The lateral and vertical electric fields boost apparent quantum efficiency for overall water splitting to 53.4% and 82.1%, respectively. Our study introduces a strategy for transitioning from intrinsic 2D-confined excited states into kinetic-driven 3D spatially separated states and paves the way for maximizing energy conversion by polymer photocatalysis.

Selectivity emerges from indiscriminate photoreduction

无差别的光还原反而催生了选择性

▲ 作者：Joseph M. Edgecomb, Arindam Sau, Niket Manoj, Matthew D. Resmini, Alissia F. Meyer, Robert S. Paton, et al.

▲链接：

https://www.nature.com/articles/s41586-026-10897-7

▲摘要：

单电子转移（SET）还原是有机化合物活化的最基本策略之一。利用SET设计选择性反应，其基础前提是底物氧化还原电位的差异可以预测SET的相对速率，即还原越有利，反应越快。

然而，在形形色色的氧化还原催化中，如何设计反应以使SET选择性地作用于两个底物中较难还原者，仍颇具挑战。当针对热力学上难以还原或难以氧化的底物时，这一限制几乎排除了偶联反应。

研究组提出了一种与底物氧化还原电位无关的替代性外层SET选择性机制。并证明超强光还原剂通过扩散限制的SET使底物氧化还原电位失去相关性，从而使得下游化学步骤与回传电子转移（BET）之间的竞争能够产生新的选择性分布。

研究组以环丙基酮与更易还原的烯烃之间的自由基环化反应为例验证了这些原理。尽管这些不匹配的氧化还原电位此前阻碍了这些反应的发生，但研究组实现了选择性自由基环化，即使所需的酮还原在热力学上变得不利（相差一个伏特量级）。更广泛而言，这些研究为设计需要突破氧化还原电位控制的选择性SET反应提供了通用蓝图。

▲ Abstract：

Single electron transfer (SET) reduction is among the most fundamental strategies for the activation of organic compounds. The design of selective reactions that leverage SET is grounded by the premise that differences in substrate redox potentials predict relative rates of SET, with more favourable reductions occurring faster. However, across the diverse modes of redox catalysis, devising reactions that require SET to the harder to reduce of two reactants remains challenging. This restriction all but precludes coupling reactions when targeting substrates that are thermodynamically difficult to reduce or oxidize. Here we introduce an alternative selectivity manifold for outer-sphere SET that is divorced from substrate redox potentials. We show that super-potent photoreductants render substrate redox potentials irrelevant through diffusion-limited SET, allowing a new selectivity profile to emerge from competition between downstream chemical steps and back electron transfer (BET). We validate these principles in the context of radical annulation reactions between cyclopropyl ketones and easier-to-reduce alkenes. Although these mismatched redox potentials previously precluded these reactions, we promote selective radical annulation even as the requisite ketone reduction becomes disfavoured by a volt. More broadly, these studies offer a general blueprint for the design of SET reactions that require violation of redox potential control.

地球科学Earth Science

Cascading continental-scale floods across Europe in 1342–1343

1342—1343年席卷欧洲大陆的连锁性特大洪水事件

▲ 作者：Andrea Kiss, Alberto Viglione, Mariano Barriendos, Silvia Enzi, Martin Bauch, Kris Decker, et al.

▲链接：

https://www.nature.com/articles/s41586-026-10888-8

▲摘要：

近几十年来，欧洲经历了极端洪水事件。然而，更大的洪水仍有可能发生，必须在洪水风险管理中加以考虑。通过分析有文献记载的历史最大洪水，有助厘清其特征。在中欧，1342年7月的马格达莱纳洪水通常被视为过去千年中最大的一次；然而，关于其特征的认识尚不完整。

研究组表明，在1341年末至1343年间，欧洲大部分地区发生了16次重大洪水事件。其中四次事件的重现期为500至1000年（即马格达莱纳洪水、巴塞洛缪洪水、圣烛节洪水和雅各布洪水）。尽管此前马格达莱纳事件被认为是1342年欧洲唯一的极端洪水，但研究组的新文献资料数据集表明，它其实只是更广泛洪水序列的一部分。

在过去700年中，极端洪水发生次数最多的年份是1342年，而1343年也位列前十。这一极不寻常的洪水序列产生了重大的社会经济影响，包括欧洲防洪减灾措施的范式转变。一系列火山喷发以及多年期的北极海冰退缩，是这一洪水序列的可能原因。

在风险管理中，决策者很少考虑在数月内集中发生的极端洪水集群。因此，亟需制定能够应对这种可能性的快速、主动的风险策略。

▲ Abstract：

Europe has experienced extreme floods in recent decades. However, even larger floods are possible and must be considered in flood risk management. Their characteristics can be clarified by analysing the largest documented historical floods. In Central Europe, the Magdalena Flood of July 1342 is usually considered the largest of the last millennium; however, knowledge of its characteristics is incomplete. Here we show that 16 major flood events occurred across much of Europe between late 1341 and 1343. Four of these events had return periods of 500–1,000 years (the Magdalena, Bartholomew, Candlemas and Jacob Floods). Although Magdalena was thought previously to be the only extreme European flood in 1342, our new documentary dataset suggests that it formed part of a broader sequence. The year with the greatest number of extreme floods during the past 700 years was 1342, and 1343 ranks among the top ten. This highly unusual sequence of floods had substantial socio-economic impacts, including a paradigm shift in flood mitigation measures in Europe. A series of volcanic eruptions along with multi-annual Arctic sea ice retreat is a plausible cause of this flood sequence. Clusters of extreme floods occurring within a few months are rarely considered in risk management. Quick and proactive risk strategies are needed that account for this eventuality.