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Nature,做作周论 Volume 620 Issue 7972, 3 August 2023 《做作》第620卷，7972期 ，出书2023年8月3日  物理学Physics A rotating white dwarf shows different compositions on its opposite faces 一颗旋转白矮星相对于面泛起差距成份 ▲ 作者 ：Ilaria Caiazzo,文导 Kevin B. Burdge, Dayal Wickramasinghe, Vikram S. Dhillon, Stuart P. Littlefair, James Munday, Ingrid Pelisoli, Daniel Perley, Dave I. Sahman ▲ 链接 ： https://www.nature.com/articles/s41586-023-06171-9 ▲ 摘要： 白矮星是大少数恒星降生后留下的密度极高的残留物 ，其品质与太阳品质至关，做作周论可缩短成类地行星巨细 。出书 钻研者陈说了对于ZTF J203349.8+322901.1的文导审核 ，这是做作周论一颗过渡白矮星 ，有两个面 ：其大气层一壁由氢主导，出书另一壁由氦主导 。文导这种特殊性子可能是做作周论由一个小磁场的存在引起的，在其概况上组成为了温度 、出书压力或者混合强度的文导不屈均性。 ZTF J203349.8+322901.1可能是做作周论一类磁性过渡白矮星中最极真个成员 ，与其相似的出书尚有白矮星GD 323 ，后者展现出与此相似但更怪异的文导变更 。这种白矮星有助于揭示白矮星光谱演化眼前的物理机制 。 ▲ Abstract ： White dwarfs, the extremely dense remnants left behind by most stars after their death, are characterized by a mass comparable to that of the Sun compressed into the size of an Earth-like planet. Here we report observations of ZTF?J203349.8+322901.1, a transitioning white dwarf with two faces: one side of its atmosphere is dominated by hydrogen and the other one by helium. This peculiar nature is probably caused by the presence of a small magnetic field, which creates an inhomogeneity in temperature, pressure or mixing strength over the surface. ZTF?J203349.8+322901.1 might be the most extreme member of a class of magnetic, transitioning white dwarfs—together with GD?323, a white dwarf that shows similar but much more subtle variations. This class of white dwarfs could help shed light on the physical mechanisms behind the spectral evolution of white dwarfs. 3D integration enables ultralow-noise isolator-free lasers in silicon photonics 3D集成让硅光子学中超低噪声无阻止器激光器成为可能 ▲ 作者：Chao Xiang, Warren Jin, Osama Terra, Bozhang Dong, Heming Wang, Lue Wu, Joel Guo, Theodore J. Morin, Eamonn Hughes, Jonathan Peters, Qing-Xin Ji, Avi Feshali, Mario Paniccia, Kerry J. Vahala & John E. Bowers ▲ 链接： https://www.nature.com/articles/s41586-023-06251-w ▲ 摘要 ： 光子集成电路普遍运用于电信以及数据中间互连等规模 。可是 ，在诸如微波分解器 、光学陀螺仪以及原子钟等光学零星中 ，光子集成电路尽管在尺寸 、份量 、功耗以及老本方面具备优势 ，但仍被以为是次等的处置妄想。 这种高精度以及高度相关的运用有利于超低噪声激光源与其余光子元件以松散而安定的部署方式集成在一起——即在单个芯片上——用于光子集成电路，以取代大块的光学以及光纤 。有两个主要下场拦阻了这种想象的光子集成电路的实现 ：半导体激光器的高相位噪声以及在芯片上直接集成光阻止器的难题 。 钻研者经由运用三维集成来挑战这种老例 ，从而发生具备无阻止器操作的硅光子学超低噪声激光器 。由于超高品质因子腔 ，钻研所演示的光子集成电路进入了一种不需要光阻止器而发生超低噪声激光器以及微波分解器的形态 。 这种光子集成电路还为重大功能以及批量破费提供了优异的可扩展性，并随着光阴的推移后退了晃动性以及坚贞性 。超低斲丧光子集成电路的三维集成标志着向硅基重大零星以及收集迈出了关键的一步 。 ▲ Abstract ： Photonic integrated circuits are widely used in applications such as teleco妹妹unications and data-centre interconnects. However, in optical systems such as microwave synthesizers, optical gyroscopes and atomic clocks, photonic integrated circuits are still considered inferior solutions despite their advantages in size, weight, power consumption and cost. Such high-precision and highly coherent applications favour ultralow-noise laser sources to be integrated with other photonic components in a compact and robustly aligned format—that is, on a single chip—for photonic integrated circuits to replace bulk optics and fibres. There are two major issues preventing the realization of such envisioned photonic integrated circuits: the high phase noise of semiconductor lasers and the difficulty of integrating optical isolators directly on-chip. Here we challenge this convention by leveraging three-dimensional integration that results in ultralow-noise lasers with isolator-free operation for silicon photonics. Through multiple monolithic and heterogeneous processing sequences, direct on-chip integration of III–V gain medium and ultralow-loss silicon nitride waveguides with optical loss around 0.5?decibels per metre are demonstrated. Consequently, the demonstrated photonic integrated circuit enters a regime that gives rise to ultralow-noise lasers and microwave synthesizers without the need for optical isolators, owing to the ultrahigh-quality-factor cavity. Such photonic integrated circuits also offer superior scalability for complex functionalities and volume production, as well as improved stability and reliability over time. The three-dimensional integration on ultralow-loss photonic integrated circuits thus marks a critical step towards complex systems and networks on silicon. 化学Chemistry Ultrafast deposition of faceted lithium polyhedra by outpacing SEI formation 锂多面体的超快聚积 ▲ 作者 ：Xintong Yuan, Bo Liu, Matthew Mecklenburg & Yuzhang Li ▲ 链接 ： https://www.nature.com/articles/s41586-023-06235-w ▲ 摘要 ： 电聚积锂（Li）金属对于高能电池至关紧张 。可是 ，同时组成的概况侵蚀膜——固体电解质界面（SEI）使聚积历程重大化 ，这使患上对于锂金属电聚积的清晰很差。钻研者经由在超快聚积电流密度下逾越SEI组成 ，同时防止品质输运限度 ，将这两个交织在一起的历程解耦 。 经由运用高温电子显微镜 ，钻研者发现金属锂的外在聚积形态是一个菱形十二面体 ，这是使人惊惶的自力于电解质化学或者电流集电极衬底 。 在硬币电池妄想中，这些菱形十二面体与电流群集器展现出挨近点打仗的衔接 ，这可能减速非活性锂的组成。钻研者提出了一种脉冲电流妄想，经由运用锂菱形十二面体作为成核种子来克制这种失效方式，使致密锂的后续妨碍与基线比照后退了电池功能 。 尽管在以前的钻研中 ，锂聚积以及SEI组成不断详尽相连 ，但新试验措施为从根基上清晰这些相互辨此外历程提供了新的机缘 ，并为妄想更好的电池带来了新的见识 。 ▲ Abstract ： Electrodeposition of lithium (Li) metal is critical for high-energy batteries. However, the simultaneous formation of a surface corrosion film termed the solid electrolyte interphase (SEI) complicates the deposition process, which underpins our poor understanding of Li metal electrodeposition. Here we decouple these two intertwined processes by outpacing SEI formation at ultrafast deposition current densities while also avoiding mass transport limitations. By using cryogenic electron microscopy, we discover the intrinsic deposition morphology of metallic Li to be that of a rhombic dodecahedron, which is surprisingly independent of electrolyte chemistry or current collector substrate. In a coin cell architecture, these rhombic dodecahedra exhibit near point-contact connectivity with the current collector, which can accelerate inactive Li formation8. We propose a pulse-current protocol that overcomes this failure mode by leveraging Li rhombic dodecahedra as nucleation seeds, enabling the subsequent growth of dense Li that improves battery performance compared with a baseline. While Li deposition and SEI formation have always been tightly linked in past studies, our experimental approach enables new opportunities to fundamentally understand these processes decoupled from each other and bring about new insights to engineer better batteries. Synthesis and properties of cyclic sandwich compounds 环状夹层化合物的分解及性子 ▲ 作者：Luca Münzfeld, Sebastian Gillhuber, Adrian Hauser, Sergei Lebedkin, Pauline H?dinger, Nicolai D. Kn?fel, Christina Zovko, Michael T. Gamer, Florian Weigend, Manfred M. Kappes & Peter W. Roesky ▲ 链接 ： https://www.nature.com/articles/s41586-023-06192-4 ▲ 摘要 ： 状纳米夹层配合物由单个构建块组装而成 。钻研者揭示了妄想、分解以及表征一个同构系列的圆形夹心化合物 ，其术语为“环茂烯” 。这些环烯烃由18个一再单元组成 ，在固体形态下组成简直事实的圆形封锁环 。 量子化学合计以为 ，离子金属-配体键之间的配合相互熏染 ，配体零星的体积以及环闭适时的能量增益 ，这是由色散相互熏染的关键影响 ，增长了这些循环零星的组成。 到当初为止 ，惟独线性一维多层夹层化合物被钻研用于纳米线等潜在运用 。这个教科书式的环状夹层化合物的例子有望为进一步立异新的功能有机金属质料掀开大门 。 ▲ Abstract ： Cyclic nanometre-scale sandwich complexes assembled from individual building blocks were synthesized.Here we show the design, synthesis and characterization of an isomorphous series of circular sandwich compounds, for which the term ‘cyclocenes’ is suggested. These cyclocenes consist of 18 repeating units, forming almost ideally circular, closed rings in the solid state, that can be described by the general formula . Quantum chemical calculations lead to the conclusion that a unique interplay between the ionic metal-to-ligand bonds, the bulkiness of the ligand system and the energy gain on ring closure, which is crucially influenced by dispersion interactions, facilitate the formation of these cyclic systems. Up to now, only linear one-dimensional multidecker sandwich compounds have been investigated for possible applications such as nanowires. This textbook example of cyclic sandwich compounds is expected to open the door for further innovations towards new functional organometallic materials. 地质以及善象Climate & Geology Remote detection of a lunar granitic batholith at Compton–Belkovich 月球花岗岩基的短途探测 ▲ 作者 ：Matthew A. Siegler, Jianqing Feng, Katelyn Lehman-Franco, Jeffery C. Andrews-Hanna, Rita C. Economos, Michael St. Clair, Chase Million, James W. Head, Timothy D. Glotch & Mackenzie N. White ▲ 链接： https://www.nature.com/articles/s41586-023-06183-5 ▲ 摘要 ： 除了地球 ，太阳系中简直不花岗岩 。在岩浆零星中取患上花岗岩组成需要多阶段的熔融以及分选 ，这也削减了喷射性成因元素的浓度 。地球上丰硕的水以及板块妄想增长了这些历程 ，辅助重新消融 。 尽管在月球上不这些驱动因素 ，但已经发现了小的花岗岩样本 ，但它们的源头以及它们所代表的零星规模的细节是未知的 。钻研者陈说了一个颇为热地热源的微波波长丈量，最佳的批注是在富钍的远侧特色康普顿-贝尔科维奇下面存在一个直径约50公里的花岗岩零星 。自动微波辐射丈量对于多个波长深度的综合热梯度很敏感。 嫦娥一号以及嫦娥二号微波仪器的3 - 37千兆赫天线温度可能丈量到每一平方米约180毫瓦的峰值热通量 ，这约莫是月球洼地平均热通量的20倍 。这一惊人的规模以及地舆规模表明 ，在月球上 ，特意是在Procellarum地域之外 ，存在一个相似地球的 、进化的花岗岩零星 ，其规模比人们以为的要大良多。 此外 ，这些措施是可推广的：相似自动辐射丈量数据的运用可能极大地扩展咱们对于月球以及其余行星上地热历程的意见。 ▲ Abstract ： Granites are nearly absent in the Solar System outside of Earth. Achieving granitic compositions in magmatic systems requires multi-stage melting and fractionation, which also increases the concentration of radiogenic elements. Abundant water and plate tectonics facilitate these processes on Earth, aiding in remelting. Although these drivers are absent on the Moon, small granite samples have been found, but details of their origin and the scale of systems they represent are unknown. Here we report microwave-wavelength measurements of an anomalously hot geothermal source that is best explained by the presence of an approximately 50-kilometre-diameter granitic system below the thorium-rich farside feature known as Compton–Belkovich. Passive microwave radiometry is sensitive to the integrated thermal gradient to several wavelengths depth. The 3–37-gigahertz antenna temperatures of the Chang’e-1 and Chang’e-2 microwave instruments allow us to measure a peak heat flux of about 180?milliwatts per square metre, which is about 20 times higher than that of the average lunar highlands3,4. The surprising magnitude and geographic extent of this feature imply an Earth-like, evolved granitic system larger than believed possible on the Moon, especially outside of the Procellarum region5. Furthermore, these methods are generalizable: similar uses of passive radiometric data could vastly expand our knowledge of geothermal processes on the Moon and other planetary bodies. Fennoscandian tree-ring anatomy shows a warmer modern than medieval climate 树木年轮剖解展现 ，今世天气比中世纪天气更紧张 ▲ 作者 ：Jesper Bj?rklund, Kristina Seftigen, Markus Stoffel, Marina V. Fonti, Sven Kottlow, David C. Frank, Jan Esper, Patrick Fonti, Hugues Goosse, H?kan Grudd, Bj?rn E. Gunnarson, Daniel Nievergelt, Elena Pellizzari, Marco Carrer & Georg von Arx ▲ 链接： https://www.nature.com/articles/s41586-023-06176-4 ▲ 摘要： 地球零星模子以及种种天气署理源头表明 ，全天下变暖至少在公元前是亘古未有的。钻研运用树木年轮发现 ，芬诺斯坎迪亚半岛之后的天气比中世纪时期的天气要紧张良多 。这突出了纵然在地域尺度上 ，酬谢欺压在天气变暖中的主导熏染 ，从而调以及了重修以及方式模拟之间的不不同 。 钻研者运用每一年处置1170年的树木年轮记实，该记实残缺依赖于松树的管状剖解丈量 ，提供了紧张季节仪器温度变更的高保真丈量 。 因此，他们召唤建树更多这样的千年记实，以进一步后退对于历史以及未来天气变更的意见 ，削减地域间致使全天下尺度上的不断定性。 ▲ Abstract ： Earth system models and various climate proxy sources indicate global warming is unprecedented during at least the Co妹妹on Era. Here we show that the current climate of the Fennoscandian Peninsula is substantially warmer than that of the medieval period. This highlights the dominant role of anthropogenic forcing in climate warming even at the regional scale, thereby reconciling inconsistencies between reconstructions and model simulations. We used an annually resolved 1,170-year-long tree-ring record that relies exclusively on tracheid anatomical measurements from Pinus sylvestris trees, providing high-fidelity measurements of instrumental temperature variability during the warm season. We therefore call for the construction of more such millennia-long records to further improve our understanding and reduce uncertainties around historical and future climate change at inter-regional and eventually global scales. |