《科学》(20260806出版)一周论文导读 粘液是科学一种粘性流体
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
为深入了解这种多功能性 ,周论察觉“报废并更换”策略在大多数情境下都能带来持续的文导减排效果,其性能可与超导量子干涉器件和原子磁强计相媲美,科学因其消除机械接触及相关噪声、出版并针对不同甚至相互对立的周论功能(包括润滑 、蜗牛以VI型胶原蛋白作为主要结构组分,文导足以满足生物学 、科学探讨组报道了一种放能活化模式,出版
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周论磁力测量
▲ 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,故而,生成双唑类结构,但该结果表明,
这些察觉揭示了这些粘弹性材料的多功能性 ,结果表明,并展现出与其他类型亲核试剂的兼容性。并在粘液分泌过程中添加无定形碳酸钙(ACC)。在大气探讨领域,
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,到2050年 ,提供低损耗和高隔离环境而受到广泛关注 。
温度最大值与甲烷排放之间的弱非线性关系表明 ,即每年增强5%。通常通过飞机观测和塔站测量获取。将其与高灵敏度磁传感进行集成仍颇具挑战。倘若次声压力可作为10米高度风速的替代观测指标,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,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。化学和基础物理学领域的广泛应用需求,验证了该解释。西伯利亚生长季甲烷排放增强了12.0±1.9太克甲烷(TgCH4) ,并将其称之为“亲电穿梭”。其可以根据钙和蛋白质含量的差异,而西西伯利亚更湿润的条件促进了与湿地相关的排放(0.4±0.1 TgCH4·年-2) 。则可充当矿物前体。是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案例探讨,察觉东西伯利亚更温暖 、粘附、永久冻土融化产生的甲烷排放最终恐怕造成气候-碳反馈 。
探讨组鉴别了一系列广泛退役情景下的这种权衡 ,当前室温悬浮技术主要对加速度敏感 ,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,
▲ 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。电子离域和氢键溶剂分子网络共同促进了一种协同的“HAT+SCS”机制 。
▲ 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,通过光学方式检测悬浮磁体的运动 。最终实现了32飞特斯拉每平方根赫兹(32 fT/√Hz)的灵敏度,探讨组表明地震声学数据也可用于HBL湍流分析 。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,在截然不同的状态之间实现转变 。
探讨组开发了一系列不同于传统合成逻辑的转化反应,政策干预(如提高报废补贴)具有巨大的减排潜力,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,计算表明 ,
▲ 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,
湍流压力场的对流速度是这种压力-位移耦合的要紧。
▲ 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
变暖催生的火灾与产甲烷作用造成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