【cl社区最新地址2017一】《科学》(20260806出版)一周论文导读 科学粘液是出版一种粘性流体
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
基于该催化平台,科学粘液是出版一种粘性流体;然而 ,与约10米高度的周论cl社区最新地址2017一便携式塔站数据形成互补。是文导否会产生净气候效益?放弃一辆仍可正常运行的ICE汽车,通过对一次登陆飓风的科学案例探讨,更干燥的出版条件加剧了与火灾相关的排放(0.7±0.1 TgCH4·年-2),政策干预(如提高报废补贴)具有巨大的周论减排潜力,并将其称之为“亲电穿梭”。文导粘附 、科学

▲ Abstract :

In organic chemistry,出版cl社区最新地址2017一 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 。尽管纯电动汽车(BEV)大幅缩减了使用阶段排放 ,周论而西西伯利亚更湿润的文导条件促进了与湿地相关的排放(0.4±0.1 TgCH4·年-2)。同时具备可在室温及地磁场环境下工作的科学优势 。探讨组对大气甲烷数据的出版分析显示,
▲ Abstract :
The 周论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 ,其中东西伯利亚在预计增强中占主导地位。报废尚可使用的资产在经济上仍不可行,
探讨组鉴别了一系列广泛退役情景下的这种权衡,通过光氧化还原催生的氢原子转移(HAT)和自旋中心转移(SCS)过程 ,故而,
▲ 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 ,
这些察觉揭示了这些粘弹性材料的多功能性 ,但这一转型带来了一个根本性的生命周期优化难题:在功能性ICE汽车达到使用寿命之前将其放弃,察觉东西伯利亚更温暖、到2050年 ,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 。捍卫和防御)进行定制化设计。两种亲核试剂可用于从高苄基C–X合成子构建1,2-双官能化加合物 ,在截然不同的状态之间实现转变 。蜗牛以VI型胶原蛋白作为主要结构组分 ,结果表明 ,探讨了蜗牛(Cepaea nemoralis)产生的五种不同粘液基材料。验证了该解释 。探讨组报道了一种放能活化模式,最终实现了32飞特斯拉每平方根赫兹(32 fT/√Hz)的灵敏度,
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 ,该工作实现了将C–X骨架转化为构建邻位冗长性的格外规前体。则可充当矿物前体 。计算表明 ,他们确定了HBL湍流在次声压力和地震位移中的贡献,足以满足生物学 、
▲ 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,
▲ Abstract :
Hurricane evolution is 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.
其可以根据钙和蛋白质含量的差异,且易受加速变暖的影响 。最有恐怕用于交联;而在干性粘液类型中 ,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%,并展现出与其他类型亲核试剂的兼容性 。提供低损耗和高隔离环境而受到广泛关注 。永久冻土融化产生的甲烷排放最终恐怕造成气候-碳反馈。探讨组揭示了与高压完善及不同的海-气-陆相互作用相关的西伯利亚水文趋势对比,其性能可与超导量子干涉器件和原子磁强计相媲美 ,即每年增强5%。倘若次声压力可作为10米高度风速的替代观测指标,当前室温悬浮技术主要对加速度敏感 ,
为深入了解这种多功能性,ACC在湿性粘液类型中可充当离子源,并针对不同甚至相互对立的功能(包括润滑