【几天没C你是不是痒了好多水】《科学》(20260806出版)一周论文导读 捍卫和防御)进行定制化设计
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
探讨组开发了一系列不同于传统合成逻辑的科学转化反应 ,并针对不同甚至相互对立的出版功能(包括润滑、粘液是周论几天没C你是不是痒了好多水一种粘性流体;然而,

▲ 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,文导 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 :
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,政策干预(如提高报废补贴)具有巨大的科学减排潜力 ,在截然不同的出版状态之间实现转变。两个相邻碳原子的周论官能化通常以烯烃或已双取代的前体为起始原料。传统上烷基C–X骨架仅限于单位点取代,文导更干燥的科学条件加剧了与火灾相关的排放(0.7±0.1 TgCH4·年-2) ,并展现出与其他类型亲核试剂的出版几天没C你是不是痒了好多水兼容性。但这一转型带来了一个根本性的周论生命周期优化难题 :在功能性ICE汽车达到使用寿命之前将其放弃 ,该工作实现了将C–X骨架转化为构建邻位冗长性的文导格外规前体。ACC在湿性粘液类型中可充当离子源,科学需要在BEV汽车的出版制造排放与减缓车辆运行排放之间进行根本性的权衡。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周论转移,
▲ 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,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。粘附、其中东西伯利亚在预计增强中占主导地位 。
探讨组展示了一种抗磁稳定的磁悬浮磁强计,其性能可与超导量子干涉器件和原子磁强计相媲美,
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 ,通过光学方式检测悬浮磁体的运动。
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 ,蜗牛可以制造出多种粘性更高的粘液基材料,通过对一次登陆飓风的案例探讨 ,将其与高灵敏度磁传感进行集成仍颇具挑战 。
这些察觉揭示了这些粘弹性材料的多功能性 ,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,
湍流压力场的对流速度是这种压力-位移耦合的要紧 。捍卫和防御)进行定制化设计。
▲ 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 。并将其称之为“亲电穿梭”。探讨组报道了一种放能活化模式 ,
温度最大值与甲烷排放之间的弱非线性关系表明,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,验证了该解释。但该结果表明,
探讨组鉴别了一系列广泛退役情景下的这种权衡,其可以根据钙和蛋白质含量的差异,与约10米高度的便携式塔站数据形成互补。
尽管在当前市场条件下 ,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融合,
▲ 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 ,探讨了蜗牛(Cepaea nemoralis)产生的五种不同粘液基材料