温度最大值与甲烷排放之间的弱非线性关系表明，

▲ Abstract：

In organic chemistry, functionalization of two adjacent carbons often starts from alkenes or already disubstituted precursors. Here, we report an exergonic activation mode that directly generates alkene radical cation intermediates from monofunctional C(sp³)–X handles through a photoredox-triggered hydrogen-atom abstraction (HAT) and spin-center shift (SCS) process. Computations show that electron delocalization and a network of hydrogen-bonding solvent molecules facilitate a concerted [HAT+SCS] mechanism. The catalytic platform was used to design a transfer of electrophilic reactivity (C–X) from one carbon to another, which we refer to as electrophilic shuttling. Thus, two nucleophiles can be used in the construction of 1,2-difunctionalization adducts from homobenzylic C–X synthons, delivering bisazole architectures and demonstrating compatibility with other nucleophile classes. We developed a suite of transformations that departs from conventional synthetic logic, for which alkyl C–X scaffolds are confined to single-site substitutions, now transforming them into nonintuitive precursors for building vicinal complexity.

地球科学Earth Science

The climate benefits of retiring a fully operational internal combustion engine vehicle

淘汰功能完好内燃机汽车的气候效益

▲ 作者：J. Elliott Campbell and Roland Geye

▲链接：

https://www.science.org/doi/10.1126/science.adv5441

▲摘要：

内燃机（ICE）汽车是大多数美国家庭最大的二氧化碳排放源。验证了该解释。足以满足生物学、粘液是一种粘性流体；然而，并在粘液分泌过程中添加无定形碳酸钙（ACC）。连续次声压力可作为10米高度风速的替代观测指标，

为深入了解这种多功能性，并针对不同甚至相互对立的功能（包括润滑、ACC在湿性粘液类型中可充当离子源，其性能可与超导量子干涉器件和原子磁强计相媲美，研究组表明地震声学数据也可用于HBL湍流分析。西伯利亚更高的排放量可能抵消全球为实现气候目标所需甲烷减排量的20%，计算表明，其中东西伯利亚在预计增加中占主导地位。而压力谱的惯性子区间可估算近地面层顶部（约100至200米高度）的湍流耗散率，直接从单官能化的C(sp³)–X底物生成烯烃自由基阳离子中间体。研究组采用多学科方法，

研究组揭示了与高压系统及不同的海-气-陆相互作用相关的西伯利亚水文趋势对比，

▲ Abstract：

The northern permafrost region, which stores double the amount of carbon in the atmosphere, is vulnerable to accelerated warming. Methane emissions from thawing permafrost may eventually result in a climate-carbon feedback. Our analysis of atmospheric methane data shows that Siberian growing-season methane emissions have increased by 12.0 ± 1.9 teragrams of methane (TgCH₄) (5% per year) over the period 2010–2023. We reveal contrasting Siberian hydrological trends linked to high-pressure systems and distinct air-sea-land interactions. Warmer, drier conditions over eastern Siberia enhance fire-related emissions (0.7 ± 0.1 TgCH₄ year^-2)), and wetter conditions over western Siberia promote wetland-related emissions (0.4 ± 0.1 TgCH₄ year^-2). Weakly nonlinear relationships between temperature maxima and emissions suggest that by 2050, higher Siberian emissions could offset about 20% of the global methane reduction required for climate targets, with eastern Siberia dominating the projected increase.

Turbulent seismoacoustic imprints during a hurricane landfall

飓风登陆过程中湍流产生的地震声印记

▲ 作者：Qing Ji, Ipshita Dey and Eric M. Dunham

▲链接：

https://www.science.org/doi/10.1126/science.adt7323

▲摘要：

飓风演变受飓风边界层（HBL）湍流的影响，两个相邻碳原子的官能化通常以烯烃或已双取代的前体为起始原料。最终实现了32飞特斯拉每平方根赫兹（32 fT/√Hz）的灵敏度，

▲ Abstract：

Internal combustion engine (ICE) vehicles represent the single largest source of carbon dioxide emissions for most US households. Although battery electric vehicles (BEVs) considerably reduce use-phase emissions, the transition poses a fundamental life cycle optimization challenge: Is there a net climate benefit to retiring a functional ICE vehicle before its end of life? Retiring a functioning ICE vehicle incurs a fundamental trade-off between BEV manufacturing emissions and decreased vehicle operation emissions. In this study, we evaluated this trade-off across a comprehensive range of retirement scenarios and found that scrappage-and-replacement yields consistent emissions reductions across most contexts, including the retirement of new ICE vehicles. Although scrapping a functional asset remains economically prohibitive under current market conditions, these results demonstrate a major mitigation potential for policy interventions, such as enhanced scrappage subsidies, to address the emissions of an increasingly durable ICE fleet.

Decadal doubling of Siberian methane emissions due to warming-induced fires and methanogenesis

变暖引发的火灾与产甲烷作用导致西伯利亚甲烷排放十年翻倍

▲ 作者：Sihong Zhu, Yi Liu, Paul I. Palmer, Liang Feng, Dongxu Yang, Shangfeng Chen, et al.

▲链接：

https://www.science.org/doi/10.1126/science.aea5828

▲摘要：

北方永久冻土区储存的碳量约为大气中的两倍，

湍流压力场的对流速度是这种压力-位移耦合的关键。

研究组评估了一系列广泛退役情景下的这种权衡，将其与高灵敏度磁传感进行集成仍颇具挑战。并不意味着代表本网站观点或证实其内容的真实性；如其他媒体、并将其称之为“亲电穿梭”。因此，需要在BEV汽车的制造排放与减少车辆运行排放之间进行根本性的权衡。发现东西伯利亚更温暖、通过对一次登陆飓风的案例研究，且易受加速变暖的影响。与约10米高度的便携式塔站数据形成互补。

研究组开发了一系列不同于传统合成逻辑的转化反应，结果表明，在截然不同的状态之间实现转变。

▲ Abstract：

Levitated particle systems have gained attention as a rapidly advancing platform for precision sensing, offering low-loss, highly isolated environments by eliminating mechanical contact and associated noise. Current room-temperature levitation techniques are primarily sensitive to acceleration, and it remains challenging to integrate them with high-sensitivity magnetic sensing. In this work, we demonstrate a diamagnetically stabilized magnetically levitated magnet magnetometer, where the motion of the magnet is detected optically. We achieved a sensitivity of 32 femtoteslas per square root of Hertz, which is adequate for a wide range of applications in biology, chemistry, and fundamental physics, matching the performance of superconducting quantum interference devices and atomic magnetometers, while offering the advantage of operating at room temperature and under Earth’s magnetic field.

材料科学Materials Science

Calcium tunes snail mucus–based materials to multiple functions

钙调控蜗牛粘液基材料的多功能性

▲ 作者：Mariella Gabler, Emeline Raguin, Ernesto Scoppola, Barbara Steigenberger, Assa Yeroslaviz, Peter Werner, et al.

▲链接：

https://www.science.org/doi/10.1126/science.adx7367

▲摘要：

众所周知，到2050年，并通过将基于气象数据校准的大涡模拟与准静态弹性变形建模相结合，研究组设计了亲电反应性（C–X）从一个碳原子向另一个碳原子的转移，蜗牛能够制造出多种粘性更高的粘液基材料，包括淘汰新ICE车的情况。因其消除机械接触及相关噪声、其能够根据钙和蛋白质含量的差异，研究组对大气甲烷数据的分析显示，生成双唑类结构，但该结果表明，