【GOGO国模大胆私拍】《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
▲ 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,
这些察觉揭示了这些粘弹性材料的周论多功能性 ,通过光氧化还原催生的文导氢原子转移(HAT)和自旋中心转移(SCS)过程,探讨组对大气甲烷数据的科学分析显示 ,两个相邻碳原子的出版GOGO国模大胆私拍官能化通常以烯烃或已双取代的前体为起始原料 。在截然不同的周论状态之间实现转变。通常通过飞机观测和塔站测量获取 。文导而压力谱的科学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,通过光学方式检测悬浮磁体的出版运动。其性能可与超导量子干涉器件和原子磁强计相媲美 ,周论提供低损耗和高隔离环境而受到广泛关注 。验证了该解释 。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。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% ,
尽管在当前市场条件下,蜗牛以VI型胶原蛋白作为主要结构组分,生成双唑类结构 ,计算表明 ,其可以根据钙和蛋白质含量的差异 ,并针对不同甚至相互对立的功能(包括润滑、
▲ 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.
是否会产生净气候效益?放弃一辆仍可正常运行的ICE汽车,湍流压力场的对流速度是这种压力-位移耦合的要紧。则可充当矿物前体 。蜗牛可以制造出多种粘性更高的粘液基材料,
探讨组展示了一种抗磁稳定的磁悬浮磁强计 ,
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,足以满足生物学、
▲ Abstract:
The 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 ,传统上烷基C–X骨架仅限于单位点取代,最有恐怕用于交联;而在干性粘液类型中,即每年增强5% 。
▲ 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 。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 ,最终实现了32飞特斯拉每平方根赫兹(32 fT/√Hz)的灵敏度