编译|未玖

Nature, 22 January 2026, Volume 649, Issue 8098

《自然》2026年1月22日，第649卷，8098期

天文学Astronomy

Accretion bursts crystallize silicates in a planet-forming disk

行星形成盘中的吸积爆发硅酸盐结晶

▲ 作者：Jeong-Eun Lee, Chul-Hwan Kim, Jaeyeong Kim, Seokho Lee, Young-Jun Kim, Seonjae Lee, et al.

▲链接：

https://www.nature.com/articles/s41586-025-09939-3

▲摘要：

结晶硅酸盐在高温条件下（>900K）形成，其在彗星中的存在表明，在早期太阳系中曾发生过高温尘埃的加工过程，随后被向外输送至形成彗星的区域。然而，关于类太阳原恒星中这种结晶和再分布仍缺乏直接证据。

通过对比詹姆斯·韦伯空间望远镜对周期性爆发的原恒星EC 53所获取的中红外光谱，研究组发现了只有在爆发期间才会出现的结晶硅酸盐（镁橄榄石和顽火辉石）发射特征。这些特征的出现表明，在吸积爆发期间，高温内部盘中通过热退火作用形成了活跃晶体。

研究组还探测到一个嵌套式的外流，即一条被较慢分子外流包围的准直原子射流，这与磁流体动力学风模型的演示一致。这种结构提供了一种新型结晶硅酸盐向外运输的机制。该结果首次报道了在一颗仍嵌入其致密外层包裹之中的极年轻恒星中，在周期性吸积爆发期间进行硅酸盐结晶的直接观测证据。

虽然研究组无法直接观测到物质颗粒被输送到外盘，但所观察到的趋势与向外重新分布保持一致，这表明尘埃处理和外输过程发生在恒星形成的最初且最为活跃的阶段。

▲ Abstract：

Crystalline silicates form at high temperatures (>900 K). Their presence in comets suggests that high-temperature dust processing occurred in the early Solar System and was subsequently transported outwards to comet-forming regions. However, direct evidence for this crystallization and redistribution in Sun-like protostars has remained unknown. By comparing James Webb Space Telescope mid-infrared spectra of the periodically bursting protostar EC 53, we detect crystalline silicate (forsterite and enstatite) emission features that appear only during the burst. The emergence of these features indicates active crystal formation by thermal annealing in the hot inner disk during the accretion burst. We also detect a nested outflow—a collimated atomic jet enclosed by slower molecular outflows, consistent with magnetohydrodynamic wind models. This configuration provides a mechanism for the outward transport of freshly crystallized silicates. To our knowledge, our results provide the first direct observational evidence of in situ silicate crystallization during episodic accretion bursts in a very young star still embedded in its dense envelope. Although we do not directly detect grains transported to the outer disk, the observed trends are consistent with outward redistribution, indicating that both dust processing and transport occur during the earliest and most dynamic stages of star formation.

物理学Physics

Symmetry, microscopy and spectroscopy signatures of altermagnetism

交变磁性的对称性、显微学及光谱学特征

▲ 作者：Tomas Jungwirth, Jairo Sinova, Rafael M. Fernandes, Qihang Liu, Hikaru Watanabe, Shuichi Murakami, et al.

▲链接：

https://www.nature.com/articles/s41586-025-09883-2

▲摘要：

新近发现的交变磁性现象，部分由补偿磁体高度可扩展自旋电子技术的研究所推动。同时，交变磁性与非常规超流相具有各向异性的高次分波有序性，后者在过去几十年里一直是研究的前沿领域。这些例子表明，从众多科学和技术的角度来看，人们对交变磁性现象都抱有浓厚的兴趣。

研究组对交变磁性的对称性、显微学观察特征以及光谱学特征进行了回顾。他们阐述了交变磁性作为一种独特物质状态的自发破缺与保留对称性，其特征为d波、g波或i波形式的补偿共线自旋序列的不同物质相。

在从弱相互作用金属到强关联绝缘体等各种材料中，交变磁性对称性的微观晶体结构实现方式都具有原子尺度自旋密度的各向异性高次分波分量的特征性铁磁序。这些交变磁性的对称性和显微镜学特征直接反映在自旋依赖的电子光谱和响应中。

研究组探讨了源自交变磁性有序现象的显著能带结构特征，及其与自旋—轨道耦合以及拓扑现象的相互作用。在整个过程中，他们将交变磁性与传统铁磁性、奈尔反铁磁性以及具有对称保护的补偿非共线自旋序磁相进行了比较。在进行理论探讨的同时，研究组还引用了相关实验依据作为参照。

▲ Abstract：

The recent discovery of altermagnetism was in part motivated by the research of compensated magnets towards highly scalable spintronic technologies. Simultaneously, altermagnetism shares the anisotropic higher-partial-wave nature of ordering with unconventional superfluid phases, which have been at the forefront of research for the past several decades. These examples illustrate the interest in altermagnetism from a broad range of science and technology perspectives. Here we review the symmetry, microscopy and spectroscopy signatures of altermagnetism. We describe the spontaneously broken and retained symmetries that delineate altermagnetism as a distinct phase of matter with d-, g- or i-wave compensated collinear spin ordering. In materials ranging from weakly interacting metals to strongly correlated insulators, the microscopic crystal-structure realizations of the altermagnetic symmetries feature a characteristic ferroic order of anisotropic higher-partial-wave components of atomic-scale spin densities. These symmetry and microscopy signatures of altermagnetism are directly reflected in spin-dependent electronic spectra and responses. We review salient band-structure features originating from the altermagnetic ordering, and from its interplay with spin–orbit coupling and topological phenomena. Throughout, we compare altermagnetism with traditional ferromagnetism and Néel antiferromagnetism, and with magnetic phases with symmetry-protected compensated non-collinear spin orders. We accompany the theoretical discussions with references to relevant experiments. 

Probing quantum mechanics with nanoparticle matter-wave interferometry

用纳米粒子物质波干涉法来探测量子力学

▲ 作者：Sebastian Pedalino, Bruno E. Ramírez-Galindo, Richard Ferstl, Klaus Hornberger, Markus Arndt & Stefan Gerlich 

▲链接：

https://www.nature.com/articles/s41586-025-09917-9

▲摘要：

量子叠加原理是物理学中的一个基本概念，也是众多量子技术的基础。然而，其往往被视为违反直觉，因为人们在日常生活的宏观尺度上并未观测到其关键特征。因此，这引发了一个有趣的问题：当增大物体的尺寸并增加其复杂性时，量子特性会保持不变还是发生变化呢？

这个问题可通过物质波干涉法来进行模型测试，其中单个大质量粒子的运动会变得离域，且需要用一个覆盖范围远大于粒子本身的波函数来描述。多年来，人们通过一系列越来越重、越来越复杂的物体来进行相关研究，并且有一个不断壮大的社群致力于将其推向更大的极限。

研究组展示了一个实验平台：其将物质波干涉现象拓展到大型金属团簇，这开创性地开辟了一种用于量子实验的定性新材料类别。该研究特别展示了钠纳米粒子的量子干涉现象，每个纳米粒子可包含超过7000多个原子，且其质量均超过170000道尔顿。

这些纳米粒子以一种宏观度为μ=15.5的“薛定谔猫”态进行传播，比以往实验结果高出一个数量级。

▲ Abstract：

The quantum superposition principle is a fundamental concept of physics and the basis of numerous quantum technologies. Yet, it is still often regarded counterintuitive because we do not observe its key features on the macroscopic scales of our daily lives. It is, therefore, interesting to ask how quantum properties persist or change as we increase the size and complexity of objects. A model test for this question can be realized by matter-wave interferometry, in which the motion of individual massive particles becomes delocalized and needs to be described by a wave function that spans regions far larger than the particle itself. Over the years, this has been explored with a series of objects of increasing mass and complexity and a growing community aims at pushing this to ever larger limits. Here we present an experimental platform that extends matter-wave interference to large metal clusters, a qualitatively new material class for quantum experiments. We specifically demonstrate quantum interference of sodium nanoparticles, which can each contain more than 7,000 atoms at masses greater than 170,000 Da. They propagate in a Schrodinger cat state with a macroscopicity of μ = 15.5, surpassing previous experiments by an order of magnitude.. 

材料科学Materials Science

3D-printed low-voltage-driven ciliary hydrogel microactuators

3D打印低电压驱动的水凝胶纤毛微致动器

▲ 作者：Zemin Liu, Che Wang, Ziyu Ren, Chunxiang Wang, Wenkang Wang, Jongkuk Ko, et al.

▲链接：

https://www.nature.com/articles/s41586-025-09944-6

▲摘要：

微米级大小、密集排列的天然纤毛能够以动态可调的集体模式进行非互易三维运动，这对于生物过程至关重要，例如微尺度移动、营养物质获取、细胞运输以及胚胎神经系统发育等。然而，受限于微米尺度上可扩展、局部可控的软体驱动，在人工系统中复制这些运动仍颇具挑战性。克服这一挑战将有助于人们更深入地理解纤毛的运动机制，阐明其在生物学中的重要性，并推动微型设备和仿生技术的发展。

研究组揭示了微米级水凝胶此前未曾被发现的无水解快速电响应现象，由低于1.5伏的电压引发，这种弯曲运动由双光子聚合3D打印的纳米级水凝胶网络的离子迁移所驱动，其发生时间仅需数毫秒。基于这些发现，研究组打印了由一种软丙烯酸—丙烯酰胺共聚（AAc-co-AAm）水凝胶（模量约为1000帕）组成的微纤毛阵列，能在毫秒内对电刺激做出反应。

每个微纤毛的直径为2至10微米，高度为18至90微米，能够以高达40赫兹的频率实现三维旋转弯曲运动，其几何形态和动力学特征与天然纤毛完全一致。这些凝胶微纤毛在经过33万次连续致动循环后仍能保持正常功能，性能衰减幅度不到30%。

这种凝胶微纤毛阵列可集成在柔性聚酰亚胺基底上，且可通过常规光刻技术实现大规模生产；亦可通过微电极阵列提供个性化的动态控制，并能够在微米尺度上实现流体操控和颗粒传输。

▲ Abstract：

Micrometre-sized, densely packed natural cilia that perform non-reciprocal 3D motions with dynamically tunable collective patterns are crucial for biological processes such as microscale locomotion, nutrient acquisition, cell trafficking and embryonic and neurological development. However, replicating these motions in artificial systems remains challenging given the limits of scalable, locally controllable soft-bodied actuation at the micrometre scale. Overcoming this challenge would enhance our understanding of ciliary dynamics, clarify their biological importance and enable new microscale devices and bioinspired technologies. Here we show a previously unrecognized fast electrical response of micrometre-scale hydrogels, induced by voltages down to 1.5 V without hydrolysis, with bending motions driven by ion migration across a nanometre-scale hydrogel network 3D-printed by two-photon polymerization, occurring within milliseconds. On the basis of these findings, we print gel microcilia arrays composed of a soft acrylic acid-co-acrylamide (AAc-co-AAm) hydrogel (modulus of approximately 1,000 Pa) that respond to electrical stimuli within milliseconds. Each microcilium measures 2–10 m in diameter and 18–90 m in height, achieving 3D rotational bending motion at up to 40 Hz, mirroring the geometry and dynamics of natural cilia. These gel microcilia maintain functionality after 330,000 continuous actuation cycles with less than 30% performance degradation. The gel microcilia arrays can be integrated on flexible polyimide substrates and fabricated at large scale using conventional lithography techniques. They also offer individual dynamic control by means of microelectrode arrays and enable fluid manipulation and particle transport at the micrometre scale. 

Sub-zero Celsius elastocaloric cooling via low-transition-temperature alloys

通过低相变温度合金实现0℃以下的弹性热制冷

▲ 作者：Guoan Zhou, Zexi Li, Zhongzheng Deng, Shuhuai Yao, Ali Safari, Lingyun Zhang, et al.

▲链接：

https://www.nature.com/articles/s41586-025-09946-4

▲摘要：

利用形状记忆合金（SMAs）进行弹性热制冷是一种极具前景的无温室气体（GHG）制冷技术，可替代依赖高全球变暖潜值（GWP）气体制冷剂的传统蒸汽压缩制冷方案。然而，现有的弹性热机系统尚未能够达到0℃以下的温度，这限制了其在各种冷冻场景中的应用。

研究组利用级联配置的低相变温度管状镍钛单元构建了一个基于压缩的级联再生式弹性热制冷装置。所选的镍钛合金在低至-20℃时仍具有超弹性特性，且熵值变化显著。此外，采用低冰点氯化钙水溶液作为传热流体，确保了在低运行温度下也能实现有效流动。

该台式设备从室温散热器中实现了-12℃的热源温度，为下一代绿色弹性热制冷技术的开发奠定了基础。

▲ Abstract：

Elastocaloric cooling using shape-memory alloys (SMAs) is a promising greenhouse gas (GHG)-free alternative to conventional vapour-compression refrigeration that relies on high global warming potential (GWP) gas refrigerants. However, existing elastocaloric systems have not yet reached sub-zero Celsius temperatures, which restricts their application in various freezing scenarios. Here we constructed a compression-based, regenerative elastocaloric cooling device using low-transition-temperature tubular NiTi units in a cascaded configuration. The selected NiTi alloy exhibited superelasticity and substantial entropy changes down to 20°C. Moreover, low-freezing-point aqueous calcium chloride solution was used as the heat-transfer fluid, ensuring effective flow at low operational temperatures. Our desktop device achieved a heat-source temperature of 12°C from a room-temperature heat sink, paving the way for next-generation green elastocaloric freezing technologies.

地球科学Earth Science

Global subsidence of river deltas

全球河流三角洲的沉降现象

▲ 作者：L. O. Ohenhen, M. Shirzaei, J. L. Davis, A. Tiwari, R. Nicholls, O. Dasho, et al.

▲链接：

https://www.nature.com/articles/s41586-025-09928-6

▲摘要：

河流三角洲支撑着全球范围内密集的人口、重要的经济中心以及至关重要的生态系统。不断上升的海平面和土地沉降给这些珍贵自然景观的可持续发展带来了威胁，因为这会导致海平面的相对上升以及随之而来的洪水、土地流失和盐碱化等灾害。尽管存在上述风险，但脆弱性评估却因缺乏当代、高分辨率、三角洲范围的沉降观测数据而受到阻碍。

研究组利用干涉合成孔径雷达技术，展示了全球40个三角洲区域内的空间不均一表面高程数据的变化。利用这一数据集，他们量化了三角洲地表高程损失，并展示了全球范围内三角洲沉降现象的普遍程度和严重程度。

研究组对导致三角洲高程变化的三个主要人为驱动因素的分析表明，40个三角洲中有10个的垂直陆地运动受地下水储量的影响最为显著。其他的三角洲要么受到多种因素的影响，要么由沉积物通量或城市扩张所主导。

此外，研究组发现，当前的地面沉降超出了绝对（地心）海平面上升现象，成为21世纪大多数三角洲相对海平面上升的主要驱动因素。这些研究结果表明，有必要采取有针对性的干预措施来解决地面下沉这一紧迫且地域性的挑战，同时也要开展更广泛的行动来减缓和适应由气候变化导致的全球海平面上升这一趋势。

▲ Abstract：

River deltas sustain dense human populations, major economic centres and vital ecosystems worldwide. Rising sea levels and subsiding land threaten the sustainability of these valuable landscapes with relative sea-level rise and associated flood, land loss and salinization hazards. Despite these risks, vulnerability assessments are impeded by the lack of contemporary, high-resolution, delta-wide subsidence observations. Here we present spatially variable surface-elevation changes across 40 global deltas using interferometric synthetic aperture radar. Using this dataset, we quantify delta surface-elevation loss and show the prevalence and severity of subsidence in river deltas worldwide. Our analysis of three key anthropogenic drivers of delta elevation changes shows that groundwater storage has the strongest relative influence on vertical land motion in 10 of the 40 deltas. The other deltas are either influenced by multiple drivers or dominated by sediment flux or urban expansion. Furthermore, we find that contemporary subsidence surpasses absolute (geocentric) sea-level rise as the dominant driver of relative sea-level rise for most deltas over the twenty-first century. These findings suggest the need for targeted interventions addressing subsidence as an immediate and localized challenge, in parallel with broader efforts to mitigate and adapt to climate change-driven global sea-level rise.