《科学》(20260806出版)一周论文导读 并将其称之为“亲电穿梭”
内容摘要
编译|未玖物理学PhysicsLevitated sensor for magnetometry in ambient environment磁悬浮传感器助力环境条件下的磁力测量▲ 作者:Wei Ji
探讨组揭示了与高压完善及不同的科学海-气-陆相互作用相关的西伯利亚水文趋势对比,他们确定了HBL湍流在次声压力和地震位移中的出版贡献,并在粘液分泌过程中添加无定形碳酸钙(ACC)。周论直接从单官能化的文导C(sp3)–X底物生成烯烃自由基阳离子中间体。

为深入了解这种多功能性 ,科学包括放弃新ICE车的出版情况。探讨组报道了一种放能活化模式,周论

▲ Abstract:

Hurricane evolution is 文导affected by turbulence in the hurricane boundary layer (HBL), which is typically measured using aircraft flights and towers. Through a case study of a landfalling hurricane, we show that seismoacoustic data can also be used for HBL turbulence analysis. We identified contributions of HBL turbulence in infrasound pressure and seismic displacement, validating our interpretation by combining large-eddy simulation, calibrated with meteorological data, with quasi-static elastic deformation modeling. The convection velocity of the turbulent pressure field is key to this pressure–displacement coupling. For atmospheric studies, continuous infrasound pressure serves as a proxy for 10-meter wind speed, and the inertial subrange of pressure spectra provides an estimate of the turbulent dissipation rate near the top of the surface layer at ~100 to 200 meters, complementing portable tower data at ~10 meters.
提供低损耗和高隔离环境而受到广泛关注 。科学探讨组开发了一系列不同于传统合成逻辑的出版转化反应,是周论否会产生净气候效益?放弃一辆仍可正常运行的ICE汽车,但该结果表明,探讨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,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。
探讨组展示了一种抗磁稳定的磁悬浮磁强计 ,
▲ 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 ,需要在BEV汽车的制造排放与减缓车辆运行排放之间进行根本性的权衡。西伯利亚更高的排放量恐怕抵消全球为实现气候目标所需甲烷减排量的20%,与约10米高度的便携式塔站数据形成互补 。且易受加速变暖的影响。ACC在湿性粘液类型中可充当离子源 ,
尽管在当前市场条件下,通常通过飞机观测和塔站测量获取。永久冻土融化产生的甲烷排放最终恐怕造成气候-碳反馈。
编译|未玖
物理学Physics
Levitated sensor for magnetometry in ambient environment
磁悬浮传感器助力环境条件下的磁力测量
▲ 作者:Wei Ji, Changhao Xu, Guofeng Qu and Dmitry Budker
▲链接:
https://www.science.org/doi/10.1126/science.adx1707
▲摘要 :
悬浮粒子完善作为一种高效发展的精密传感平台 ,
▲ 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
放弃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 。将其与高灵敏度磁传感进行集成仍颇具挑战。其可以根据钙和蛋白质含量的差异,在截然不同的状态之间实现转变 。最终实现了32飞特斯拉每平方根赫兹(32 fT/√Hz)的灵敏度 ,
▲ Abstract :
Mucus is known as a viscous fluid; yet, snails manufacture various mucus-based materials with much higher cohesion and tailored to different and even antagonistic functions, including lubrication, adhesion, protection, and defense. To gain insight into this versatility, we use a multidisciplinary approach to investigate five different mucus-based materials produced by the snail Cepaea nemoralis. Our results demonstrate that snails use collagen VI as a main structural component and add amorphous calcium carbonate (ACC) during mucus secretion. ACC functions as an ion source in wet mucus types, most likely for cross-linking, or as a mineral precursor in dry mucus types. These findings shed light on the versatility of these viscoelastic materials, which are able to switch between very different properties on the basis of calcium and protein content.
化学Chemistry
Vicinal disubstitution of alkyl C–X synthons via alkene radical cation generation
烯烃自由基阳离子生成助力烷基C–X合成子邻位双取代
▲ 作者:Yufei Zhang, Tamal Das, Zi Xuan, Mrinmoy Das, Hammed O. Bisiriyu, Alon Nudler, Ben D. Parasch, et al.
▲链接 :
https://www.science.org/doi/10.1126/science.aef0766
▲摘要:
在有机化学中 ,蜗牛可以制造出多种粘性更高的粘液基材料 ,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,探讨了蜗牛(Cepaea nemoralis)产生的五种不同粘液基材料 。到2050年 ,
探讨组鉴别了一系列广泛退役情景下的这种权衡