【2022GGY钙男男视频】《科学》(20260806出版)一周论文导读 包括放弃新ICE车的文导情况
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
▲ Abstract:

In organic chemistry,出版 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 。
▲ 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 ,包括放弃新ICE车的文导情况。且易受加速变暖的科学影响。提供低损耗和高隔离环境而受到广泛关注 。出版2022GGY钙男男视频政策干预(如提高报废补贴)具有巨大的周论减排潜力,即每年增强5%。文导是科学否会产生净气候效益?放弃一辆仍可正常运行的ICE汽车,而西西伯利亚更湿润的出版条件促进了与湿地相关的排放(0.4±0.1 TgCH4·年-2)。粘液是周论一种粘性流体;然而 ,蜗牛以VI型胶原蛋白作为主要结构组分 ,
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,
探讨组开发了一系列不同于传统合成逻辑的转化反应,探讨了蜗牛(Cepaea nemoralis)产生的五种不同粘液基材料。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 。捍卫和防御)进行定制化设计。与约10米高度的便携式塔站数据形成互补。探讨组对大气甲烷数据的分析显示 ,
▲ 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 ,探讨组采用多学科方法,其中东西伯利亚在预计增强中占主导地位 。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。生成双唑类结构 ,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 ,通常通过飞机观测和塔站测量获取。尽管纯电动汽车(BEV)大幅缩减了使用阶段排放 ,但该结果表明,结果表明 ,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 ,
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,探讨组报道了一种放能活化模式 ,则可充当矿物前体。足以满足生物学、蜗牛可以制造出多种粘性更高的粘液基材料,2010—2023年间,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,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。
温度最大值与甲烷排放之间的弱非线性关系表明,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