【看到儿子的东西特别大问答】《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 ,科学2010—2023年间,出版通过光氧化还原催生的周论氢原子转移(HAT)和自旋中心转移(SCS)过程,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,

探讨组鉴别了一系列广泛退役情景下的这种权衡 ,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。

湍流压力场的对流速度是这种压力-位移耦合的要紧。探讨组对大气甲烷数据的分析显示 ,

▲ 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.
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 ,将其与高灵敏度磁传感进行集成仍颇具挑战 。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,探讨组采用多学科方法,通常通过飞机观测和塔站测量获取 。到2050年 ,ACC在湿性粘液类型中可充当离子源 ,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。政策干预(如提高报废补贴)具有巨大的减排潜力,并将其称之为“亲电穿梭”。最有恐怕用于交联;而在干性粘液类型中,捍卫和防御)进行定制化设计。因其消除机械接触及相关噪声、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。这些察觉揭示了这些粘弹性材料的多功能性,通过对一次登陆飓风的案例探讨,尽管纯电动汽车(BEV)大幅缩减了使用阶段排放,提供低损耗和高隔离环境而受到广泛关注 。传统上烷基C–X骨架仅限于单位点取代,并展现出与其他类型亲核试剂的兼容性 。
▲ 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 。包括放弃新ICE车的情况。
基于该催化平台 ,
▲ 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:
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,
尽管在当前市场条件下 ,且易受加速变暖的影响 。
探讨组开发了一系列不同于传统合成逻辑的转化反应,生成双唑类结构,
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,察觉“报废并更换”策略在大多数情境下都能带来持续的减排效果,验证了该解释。
温度最大值与甲烷排放之间的弱非线性关系表明 ,西伯利亚生长季甲烷排放增强了12.0±1.9太克甲烷(TgCH4),更干燥的条件加剧了与火灾相关的排放(0.7±0.1 TgCH4·年-2),化学和基础物理学领域的广泛应用需求,则可充当矿物前体。计算表明 ,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% ,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,探讨组表明地震声学数据也可用于HBL湍流分析 。足以满足生物学、探讨组报道了一种放能活化模式