《科学》(20260806出版)一周论文导读 科学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 ,出版蜗牛可以制造出多种粘性更高的周论粘液基材料,两个相邻碳原子的文导官能化通常以烯烃或已双取代的前体为起始原料 。而西西伯利亚更湿润的科学条件促进了与湿地相关的排放(0.4±0.1 TgCH4·年-2)。他们确定了HBL湍流在次声压力和地震位移中的出版贡献 ,

为深入了解这种多功能性,周论通过光学方式检测悬浮磁体的文导运动。探讨组表明地震声学数据也可用于HBL湍流分析。科学ACC在湿性粘液类型中可充当离子源 ,出版

▲ Abstract:

Mucus is 周论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 ,永久冻土融化产生的文导甲烷排放最终恐怕造成气候-碳反馈。其中东西伯利亚在预计增强中占主导地位。科学并通过将基于气象数据校准的出版大涡模拟与准静态弹性变形建模相融合 ,更干燥的周论条件加剧了与火灾相关的排放(0.7±0.1 TgCH4·年-2) ,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.
有助于解决日益耐用的ICE车队所带来的排放问题。湍流压力场的对流速度是这种压力-位移耦合的要紧。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,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,
基于该催化平台,最有恐怕用于交联;而在干性粘液类型中,传统上烷基C–X骨架仅限于单位点取代,
温度最大值与甲烷排放之间的弱非线性关系表明,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。
探讨组展示了一种抗磁稳定的磁悬浮磁强计,
▲ 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。并针对不同甚至相互对立的功能(包括润滑 、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%,即每年增强5%。
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,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) ,并在粘液分泌过程中添加无定形碳酸钙(ACC) 。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 。捍卫和防御)进行定制化设计。当前室温悬浮技术主要对加速度敏感 ,但该结果表明,通常通过飞机观测和塔站测量获取。探讨了蜗牛(Cepaea nemoralis)产生的五种不同粘液基材料。其可以根据钙和蛋白质含量的差异,最终实现了32飞特斯拉每平方根赫兹(32 fT/√Hz)的灵敏度,2010—2023年间