编译|未玖
Nature, 21 August 2025, Volume 644 Issue 8077
《自然》，2025年8月21日，第644卷，8077期
天文学Astronomy
Extremely stripped supernova reveals a silicon and sulfur formation site
极度剥离的超新星揭示了硅和硫的形成位置
▲ 作者：Steve Schulze, Avishay Gal-Yam et al.
▲链接：
https://www.nature.com/articles/s41586-025-09375-3
▲摘要：
恒星最初由氢和氦的聚变提供能量。这些灰烬在一系列阶段中充当燃料，将大质量恒星转变成壳层结构。这些壳层结构由外部原生氢和内部连续较重的成分组成，预计主要由He、C/O、O/Ne/Mg和O/Si/S组成。硅和硫融合成铁，导致核心坍塌，要么发生超新星爆炸，要么形成黑洞。
剥离恒星的外层氢层被移除后，内部富氦层甚至其下方的C/O层暴露出来，为这种壳层结构及其所反映的宇宙元素产生机制提供了证据。由剥离恒星嵌入星周物质（CSM）壳中产生的超新星类型证实了这一情况。然而，目前尚无直接证据表明，大多数内壳负责产生比氧重的元素。
研究组报道了超新星（SN 2021yfj的发现，由一颗恒星剥离至其富O/Si/S层而产生。他们直接观察到一层厚厚的富Si/S壳层，在超新星爆炸前不久由前身恒星排出。从理论上讲，揭示这样的恒星内层颇具挑战性，可能需要一种很少观测到的质量损失机制。这一罕见的超新星事件揭示了恒星演化的高级阶段，形成了比任何已知大质量恒星表面检测到的更重的元素，包括硅、硫和氩。
▲ Abstract：
Stars are initially powered by the fusion of hydrogen to helium. These ashes serve as fuel in a series of stages, transforming massive stars into a structure of shells. These are composed of natal hydrogen on the outside and consecutively heavier compositions inside, predicted to be dominated by He, C/O, O/Ne/Mg and O/Si/S. Silicon and sulfur are fused into iron, leading to the collapse of the core and either a supernova explosion or the formation of a black hole. Stripped stars, in which the outer hydrogen layer has been removed and the internal He-rich or even the C/O layer below it is exposed, provide evidence for this shell structure and the cosmic element production mechanism it reflects. The supernova types that arise from stripped stars embedded in shells of circumstellar material (CSM) confirm this scenario. However, direct evidence for the most interior shells, which are responsible for producing elements heavier than oxygen, is lacking. Here we report the discovery of the supernova (SN) 2021yfj resulting from a star stripped to its O/Si/S-rich layer. We directly observe a thick, massive Si/S-rich shell, expelled by the progenitor shortly before the supernova explosion. Exposing such an inner stellar layer is theoretically challenging and probably requires a rarely observed mass-loss mechanism. This rare supernova event reveals advanced stages of stellar evolution, forming heavier elements, including silicon, sulfur and argon, than those detected on the surface of any known class of massive stars.
材料科学Materials Science
Electrochemical loading enhances deuterium fusion rates in a metal target
电化学加载提高了金属靶中的氘聚变速率
▲ 作者：Kuo-Yi Chen, Jannis Maiwald et al.
▲链接：
https://www.nature.com/articles/s41586-025-09042-7
▲摘要：
能源应用的核聚变研究旨在创造条件，释放比触发聚变过程所需的更多能量。为了产生有意义的能量，氘等燃料需要在空间上受到限制，以增加粒子的碰撞概率。因此，研究组着手探讨用氘燃料电化学加载金属晶格是否会增加核聚变事件的概率。
他们报告了一个台式聚变反应堆，实现了用氘离子轰击钯金属靶。这些氘离子在钯金属中发生氘-氘聚变反应。研究组发现，将氘原位电化学加载到钯靶中导致氘-氘聚变速率提高了15（2）%。该实验展示了金属靶在电子伏特能级上的电化学加载如何影响兆电子伏特能级上的核反应。
▲ Abstract：
Nuclear fusion research for energy applications aims to create conditions that release more energy than required to initiate the fusion process. To generate meaningful amounts of energy, fuels such as deuterium need to be spatially confined to increase the collision probability of particles. We therefore set out to investigate whether electrochemically loading a metal lattice with deuterium fuel could increase the probability of nuclear fusion events. Here we report a benchtop fusion reactor that enabled us to bombard a palladium metal target with deuterium ions. These deuterium ions undergo deuterium–deuterium fusion reactions within the palladium metal. We showed that the in situ electrochemical loading of deuterium into the palladium target resulted in a 15(2)% increase in deuterium–deuterium fusion rates. This experiment shows how the electrochemical loading of a metal target at the electronvolt energy scale can affect nuclear reactions at the megaelectronvolt energy scale.
Delocalized electrolyte design enables 600 Wh kg?1 lithium metal pouch cells
离域电解液设计实现600 Wh kg?1 锂金属软包电池
▲ 作者：He Huang, Yitao Hu et al.
▲链接：
https://www.nature.com/articles/s41586-025-09382-4
▲摘要：
高能锂金属电池（LMBs）的发展对于下一代储能和电动汽车技术的进步至关重要。然而，LMB的实际应用受到当前依赖于主要溶剂化结构的电解液设计的限制，阻碍了性能优化的变革式进展。
研究组通过一种离域电解液设计来解决这一限制，促进了更无序的溶剂化微环境，从而减轻了动力学障碍并稳定了界面相。所得到的离域电解液在5.5 Ah、贫电解液设计的LiNi0.9Co0.05Mn0.05O2(Ni90) || 锂软包电池中能量密度高达604.2 Wh kg-1，可稳定循环100次；在5.2 Ah、超贫电解液设计（0.9 g Ah-1）的Ni90||锂袋电池中可稳定循环90次。
此外，70-104 V NCM811||锂电池组（3904 Wh）具有480.9 Wh kg?1的高能量密度和超过25次的稳定循环。这些结果表明，在电解液设计中需要克服对主要溶剂化结构的固有依赖，以实现高能Battery600和可扩展的Pack480目标。
▲ Abstract：
The development of high-energy lithium metal batteries (LMBs) is essential for advances in next-generation energy storage and electric vehicle technologies. Nevertheless, the practical applications of LMBs are constrained by current electrolyte designs that inherently rely on dominant solvation structures, preventing transformative progress in performance optimization. Here, we address this limitation through a delocalized electrolyte design that fosters a more disordered solvation microenvironment, thereby mitigating dynamic barriers and stabilizing interphases. The resulting delocalized electrolyte delivers notable energy densities of 604.2?Wh?kg?1 in a 5.5-Ah LiNi0.9Co0.05Mn0.05O2(Ni90)||Li pouch cell with a lean electrolyte design (1.0?g?Ah?1) and 618.2?Wh?kg?1 in a 5.2-Ah Ni90||Li pouch cell with an ultralean electrolyte design (0.9?g?Ah?1), maintaining significant cycle stability over 100 and 90 cycles, respectively. In addition, the 70–104?V NCM811||Li battery pack (3,904?Wh) exhibits a high energy density of 480.9?Wh?kg?1 and stable cycling over 25 cycles. These results demonstrate the need to circumvent inherent reliance on dominant solvation structures in electrolyte design to achieve the high-energy Battery600 and scalable Pack480 targets.
化学Chemistry
Acidic oxygen reduction by single-atom Fe catalysts on curved supports
弯曲载体上单原子铁催化剂的酸性氧还原
▲ 作者：Yasong Zhao, Jiawei Wan et al.
▲链接：
https://www.nature.com/articles/s41586-025-09364-6
▲摘要：
为高性价比的质子交换膜燃料电池开发高活性、耐用的电催化剂颇具挑战。Fe/N-C催化剂是铂族金属催化剂中最有前景的替代品之一，但由于氧化反应中间体的强吸附和Fenton反应引起的Fe物种脱金属，其活性和耐久性仍未满足性能标准。
研究组设计并开发了一种新型的Fe/N-C催化剂，由分散在二维碳层上的多个纳米突起组成，单个铁原子位点主要嵌入在纳米突起的内曲面上。纳米突起的石墨化外碳层不仅能有效削弱氧化反应中间体的结合强度，还能降低羟基自由基的生成速率。
结果表明，Fe/N-C催化剂提供了一种性能最佳的无铂族金属质子交换膜燃料电池，在1.0 bar H2-空气下实现了0.75 W cm-2的创纪录高功率密度，在连续运行超过300小时后，活性保持率为86%。
▲ Abstract：
Developing highly active and durable electrocatalysts for cost-effective proton-exchange membrane fuel cells is challenging. Fe/N–C catalysts are among the most promising alternatives to the platinum group metal catalysts, but their activity and durability still cannot meet the performance criteria due to the strong adsorption of oxygenated reaction intermediates and the demetallization of Fe species caused by the Fenton reaction. Here we design and develop a new type of Fe/N–C catalyst that is composed of numerous nanoprotrusions dispersed on two-dimensional carbon layers with single Fe-atom sites primarily embedded within the inner curved surface of the nanoprotrusions. The graphitized outer carbon layer of the nanoprotrusions can not only effectively weaken the binding strength of the oxygenated reaction intermediates, but also reduce the hydroxyl radical production rate. As a result, the Fe/N–C catalyst delivers one of the best-performing platinum group metal-free proton-exchange membrane fuel cell performances, achieving a record high power density of 0.75?W?cm?2under 1.0?bar H2–air with 86% activity retention after more than 300?hours of continuous operation.
地球科学Earth Science
Tropical response to ocean circulation slowdown raises future drought risk
热带对海洋环流减缓的响应增加了未来的干旱风险
▲ 作者：Pedro N. DiNezio, Timothy M. Shanahan et al.
▲链接：
https://www.nature.com/articles/s41586-025-09319-x
▲摘要：
全球变暖下的热带降雨预测仍然高度不确定，主要是因为气候对大西洋经向翻转环流（AMOC）可能减弱的响应不明确。尽管AMOC的减缓可以大幅改变热带降雨模式，但人们对高纬度变化与热带水文气候之间的物理机制知之甚少。
研究组证明了AMOC的减缓通过高纬度冷却向热带北大西洋的传播，驱动了热带降雨的广泛变化。他们利用气候模型模拟和Heinrich Stadial 1（HS1）的古气候记录（AMOC明显减弱的过去时期）确定并验证了这一机制。
在模型中，盛行东风和西风通过热带和亚热带北大西洋上空的冷空气输送，将气候信号传递到太平洋和印度洋。海气相互作用将这种响应传递到太平洋和印度洋，改变了远至印度尼西亚、热带安第斯山脉和澳大利亚北部的降雨模式。
在全球变暖情景下出现了类似的遥相关，产生了一致的多模型热带水文气候变化模式。这些经过古气候验证的预测表明，中美洲、亚马逊和西非地区普遍干旱，突显出脆弱的人类和生态系统面临严重干旱的风险增加。
▲ Abstract：
Projections of tropical rainfall under global warming remain highly uncertain, largely because of an unclear climate response to a potential weakening of the Atlantic meridional overturning circulation (AMOC). Although an AMOC slowdown can substantially alter tropical rainfall patterns, the physical mechanisms linking high-latitude changes to tropical hydroclimate are poorly understood. Here we demonstrate that an AMOC slowdown drives widespread shifts in tropical rainfall through the propagation of high-latitude cooling into the tropical North Atlantic. We identify and validate this mechanism using climate model simulations and palaeoclimate records from Heinrich Stadial 1 (HS1)—a past period marked by pronounced AMOC weakening. In models, prevailing easterly and westerly winds communicate the climate signal to the Pacific Ocean and Indian Ocean through the transport of cold air generated over the tropical and subtropical North Atlantic. Air–sea interactions transmit the response across the Pacific Ocean and Indian Ocean, altering rainfall patterns as far as Indonesia, the tropical Andes and northern Australia. A similar teleconnection emerges under global warming scenarios, producing a consistent multi-model pattern of tropical hydroclimatic change. These palaeo-validated projections show widespread drying across Mesoamerica, the Amazon and West Africa, highlighting an elevated risk of severe drought for vulnerable human and ecological systems.
Human emissions drive recent trends in North Pacific climate variations
人为排放驱动了北太平洋气候变化的最近趋势
▲ 作者：Jeremy M. Klavans, Pedro N. DiNezio et al.
▲链接：
https://www.nature.com/articles/s41586-025-09368-2
▲摘要：
太平洋年代际振荡（PDO）是驱动北太平洋及周边大陆变化的主要气候变率模式，现在被认为是由气候系统内部过程产生的。根据这一范式，PDO的特征性不规则振荡源于北太平洋和热带太平洋海-气相互作用的一系列机制。
最近海-气耦合系统的变化（如2015年的厄尔尼诺）本应已将PDO转变为正相位。然而，30多年来，PDO一直处于持续下降的趋势，使附近地区受到一系列稳定的气候影响。
研究组表明，20世纪PDO指数的主要多年代际变化，包括持续数十年的负趋势，主要是由人为排放的气溶胶和温室气体驱动的，而非内部过程。这种人为影响以前未被发现，因为当前一代气候模型系统地低估了强迫气候变率的幅度。
一种新的归因技术在统计学上纠正了这一错误，通过外部强迫的PDO变化，表明观测到的PDO影响（包括美国西部持续数十年的干旱）可在很大程度上归因于人类活动。这些结果表明，研究组需要重新思考区域气候多年代际变化的归因和预测。
▲ Abstract：
The Pacific decadal oscillation (PDO)—the leading pattern of climate variability driving changes over the North Pacific and surrounding continents—is now thought to be generated by processes internal to the climate system. According to this paradigm, the characteristic, irregular oscillations of the PDO arise from a collection of mechanisms involving ocean and atmosphere interactions in the North and tropical Pacific. Recent variations in the coupled ocean–atmosphere system, such as the 2015 El Ni?o, ought to have shifted the PDO into its positive phase. Yet, the PDO has been locked in a consistent downward trend for more than three decades, remanding nearby regions to a steady set of climate impacts. Here we show that the main multidecadal variations in the PDO index during the twentieth century, including the ongoing, decades-long negative trend, were largely driven by human emissions of aerosols and greenhouse gases rather than internal processes. This anthropogenic influence was previously undetected because the current generation of climate models systematically underestimate the amplitude of forced climate variability. A new attribution technique that statistically corrects for this error suggests that observed PDO impacts—including the ongoing multidecadal drought in the western United States—can be largely attributed to human activity through externally forced changes in the PDO. These results indicate that we need to rethink the attribution and projection of multidecadal changes in regional climate.
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