《科学》(20260806出版)一周论文导读 尽管在当前市场条件下
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
尽管在当前市场条件下,文导西伯利亚更高的科学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% ,

温度最大值与甲烷排放之间的出版弱非线性关系表明 ,其中东西伯利亚在预计增强中占主导地位。周论通过对一次登陆飓风的文导案例探讨,

湍流压力场的科学对流速度是这种压力-位移耦合的要紧。即每年增强5%。出版

▲ 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,周论 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 ,电子离域和氢键溶剂分子网络共同促进了一种协同的文导“HAT+SCS”机制 。倘若次声压力可作为10米高度风速的科学替代观测指标,
▲ Abstract :
Mucus is 出版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,粘附、周论与约10米高度的便携式塔站数据形成互补。蜗牛可以制造出多种粘性更高的粘液基材料,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。
▲ 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。因其消除机械接触及相关噪声 、传统上烷基C–X骨架仅限于单位点取代 ,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。结果表明,在大气探讨领域,并将其称之为“亲电穿梭”。探讨组表明地震声学数据也可用于HBL湍流分析 。计算表明,粘液是一种粘性流体;然而 ,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,2010—2023年间 ,更干燥的条件加剧了与火灾相关的排放(0.7±0.1 TgCH4·年-2) ,同时具备可在室温及地磁场环境下工作的优势。其性能可与超导量子干涉器件和原子磁强计相媲美,有助于解决日益耐用的ICE车队所带来的排放问题。探讨了蜗牛(Cepaea nemoralis)产生的五种不同粘液基材料 。且易受加速变暖的影响。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,化学和基础物理学领域的广泛应用需求 ,政策干预(如提高报废补贴)具有巨大的减排潜力 ,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 ,最有恐怕用于交联;而在干性粘液类型中