天博《自然》（20230914出版）一周论文导读—新闻—科学网
来源：天博企业
发表时间:
2024-08-22
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Nature, Volume 621 Issue 7978, 14 September 2023 《天然》，2023年9月14日，第621卷，7978期 物理学Physics Subsecond periodic radio oscillations in a microquasar 微类星体的亚秒周期无线电振荡 ▲ 作者：Pengfu Tian, Ping Zhang, Wei Wang, Pei Wang, Xiaohui Sun, Jifeng Liu, Bing Zhang, Zigao Dai, Feng Yuan, Shuangnan Zhang, Qingzhong Liu, Peng Jiang, Xuefeng Wu, Zheng Zheng, Jiashi Chen, Di Li, Zonghong Zhu, Zhichen Pan, Hengqian Gan, Xiao Chen Na Sai ▲ 链接： https://www.nature.com/articles/s41586-023-06336-6 ▲ 择要： 强盛的相对于论性喷流是所有标准吸积黑洞遍及存于的特性之一。GRS1915 + 105是一个闻名的倏地扭转黑洞X射线双星，超光速射电发射运动注解其具备相对于论性喷流，被称为 微类星体 。已往30年里，它体现出连续的X射线勾当，X射线带的准周期振荡约为1至10Hz和34以及67Hz。 这些振荡可能发源在内部吸积盘，但也有人以为有其他的发源。射电不雅测发明其具备准周期耀斑或者振荡的可变光曲线，周期约为20至50分钟。研究者陈诉了发生于2021年1月以及2022年6月的1.05至1.45GHz无线电频段中检测到的源的约莫5Hz瞬态周期性振荡特性的两个实例。于振荡阶段也不雅察到圆偏振。 ▲ Abstract： Powerful relativistic jets are one of the ubiquitous features of accreting black holes in all scales. GRS 1915 + 105 is a well-known fast-spinning black-hole X-ray binary with a relativistic jet, termed a microquasar , as indicated by its superluminal motion of radio emission. It has exhibited persistent X-ray activity over the last 30 years, with quasiperiodic oscillations of approximately 1 10 Hz and 34 and 67 Hz in the X-ray band. These oscillations probably originate in the inner accretion disk, but other origins have been considered11. Radio observations found variable light curves with quasiperiodic flares or oscillations with periods of approximately 20 50 min. Here we report two instances of approximately 5-Hz transient periodic oscillation features from the source detected in the 1.05- to 1.45-GHz radio band that occurred in January 2021 and June 2022. Circular polarization was also observed during the oscillation phase. Quantum oscillations of the quasiparticle lifetime in a metal 金属中准粒子寿命的量子振荡 ▲ 作者：：Nico Huber, Valentin Leeb, Andreas Bauer, Georg Benka, Johannes Knolle, Christian Pfleiderer Marc A. Wilde ▲ 链接： https://www.nature.com/articles/s41586-023-06330-y ▲ 择要： 颠末近一个世纪的研究，金属的低洼引发怎样能用非彼此作用带的有用单粒子理论很好地注释，仍旧是一个谜。真实质料中富厚的彼此作用提出了逾越有用的单粒子、单波段举动征象的间接光谱特性问题。研究者报导了三维拓扑半金属CoSi中量子振荡的辨认，它于两个基本方面违反了尺度描写。 起首，振荡频次对于应在两个带的半经典准粒子轨道的差，由于轨道的一半会与洛伦兹力相反，以是是克制的。其次，振荡存于在50K以上，与所有其他振荡身分造成强烈对于比，它们于几个开尔文如下就消散了。 研究者发明这与半经典准粒子生命周期(QPL)的量子振荡的通用模子计较很是一致。它们存于的独一条件是至少两个电子轨道的非线性耦合，例如，因为缺陷或者团体激励上的半经典准粒子散射，QPL的量子振荡对于在具备多个轨道的朗道量子化的任何金属都是通用的。它们与拓扑半金属、很是规超导体、稀土化合物以及Rashba体系中的某些频次一致，并答应辨认以及丈量相干征象，例如，二维质料以及多波段金属中。 ▲ Abstract： Following nearly a century of research, it remains a puzzle that the low-lying excitations of metals are remarkably well explained by effective single-particle theories of non-interacting bands. The abundance of interactions in real materials raises the question of direct spectroscopic signatures of phenomena beyond effective single-particle, single-band behaviour. Here we report the identification of quantum oscillations (QOs) in the three-dimensional topological semimetal CoSi, which defy the standard description in two fundamental aspects. First, the oscillation frequency corresponds to the difference of semiclassical quasiparticle (QP) orbits of two bands, which are forbidden as half of the trajectory would oppose the Lorentz force. Second, the oscillations exist up to above 50 K, in strong contrast to all other oscillatory components, which vanish below a few kelvin. Our findings are in excellent agreement with generic model calculations of QOs of the QP lifetime (QPL). Because the only precondition for their existence is a nonlinear coupling of at least two electronic orbits, for example, owing to QP scattering on defects or collective excitations, such QOs of the QPL are generic for any metal featuring Landau quantization with several orbits. They are consistent with certain frequencies in topological semimetals unconventi�첩onal superconductors10,11, rare-earth compounds and Rashba systems, and permit to identify and gauge correlation phenomena, for example, in two-dimensional materials and multiband metals. 化学Chemistry Sustainably sourced components to generate high-strength adhesives 哄骗可连续采购组件出产高强度粘合剂 ▲ 作者：Clayton R. Westerman, Bradley C. McGill Jonathan J. Wilker ▲ 链接： https://www.nature.com/articles/s41586-023-06335-7 ▲ 择要： 险些所有粘合剂都是从石油中提取的，可以造成永世的粘合剂，拦阻质料的收受接管分散和垃圾填埋场烧毁物的降解。 当试图从石油原料转向可连续质料生态体系时，现有的选择遭到机能低、成本高或者缺少所需范围可用性的影响。研究者提出了一种可连续来历的粘合剂体系，由环氧年夜豆油、苹果酸以及单宁酸制成，其机能可与今朝的工业产物相媲美。 这类粘合剂可于各类前提下固化，从使用吹风机5分钟到于180℃的烤箱中固化24小时。金属基材之间的附出力高达18MPa摆布，于最佳的环境下，机能跨越了传统的环氧树脂，这是最强盛的现代粘合剂。所有组件都是生物资衍生的，成本低，且可用量年夜。新粘合剂或者有助在质料的可连续粘合。 ▲ Abstract： Nearly all adhesives are derived from petroleum, create permanent bonds, frustrate materials separation for recycling and prevent degradation in landfills. When trying to shift from petroleum feedstocks to a sustainable materials ecosystem, available options suffer from low performance, high cost or lack of availability at the required scales. Here we present a sustainably sourced adhesive system, made from epoxidized soy oil, malic acid and tannic acid, with performance comparable to that of current industrial products. Joints can be cured under conditions ranging from use of a hair dryer for 5 min to an oven at 180 C for 24 h. Adhesion between metal substrates up to around 18 MPa is achieved, and, in the best cases, performance exceeds that of a classic epoxy, the strongest modern adhesive. All components are biomass derived, low cost and already available in large quantities. Manufacturing at scale can be a simple matter of mixing and heating, suggesting that this new adhesive may contribute towards the sustainable bonding of materials. Single molecule infrared spectroscopy in the gas phase 气相单份子红外光谱 ▲ 作者：Aaron Calvin, Scott Eierman, Zeyun Peng, Merrell Brzeczek, Lincoln Satterthwaite David Patterson ▲ 链接： https://www.nature.com/articles/s41586-023-06351-7 ▲ 择要： 光谱学是一种要害的阐发东西，提供了对于份子布局有价值的见解，并被广泛用在辨认化学样品。标志光谱学是作用光谱学的一种情势，此中经由过程掉去弱附着的惰性 标志 粒子(例如He、Ne、N2)来检测份子离子对于单个光子的接收。 接收光谱由标签丧失率作为入射辐射频次的函数导出。到今朝为止，所有气相多原子份子的光谱都局限在年夜份子系，是以因为存于多种化学以及同分异构体，光谱注释变患上繁杂。 研究者提出了一种新的标志光谱方案来阐发最纯净的样品：单个气相份子。他们经由过程丈量单个气相(C7H7+)份子离子的红外光谱来证实该技能。该要领的高敏捷度展现了传统标志要领未不雅察到的光谱特性。 准则上，该要领可经由过程一次辨认一个构成份子来阐发多组分混淆物。单份子敏捷度将作用光谱学扩大到罕见样品，例如来自外星的样品，或者者于传统作用要领中密渡过低的数目密度下造成的反映中间体。 ▲ Abstract： Spectroscopy is a key analytical tool that provides valuable insight into molecular structure and is widely used to identify chemical samples. Tagging spectroscopy is a form of action spectroscopy in which the absorption of a single photon by a molecular ion is detected via the loss of a weakly attached, inert tag particle (for example, He, Ne, N2). The absorption spectrum is derived from the tag loss rate as a function of incident radiation frequency. So far, all spectroscopy of gas phase polyatomic molecules has been restricted to large molecular ensembles, thus complicating spectral interpretation by the presence of multiple chemical and isomeric species. Here we present a novel tagging spectroscopic scheme to analyse the purest possible sample: a single gas phase molecule. We demonstrate this technique with the measurement of the infrared spectrum of a single gas phase tropylium (C7H7+) molecular ion. The high sensitivity of our method revealed spectral features not previously observed using traditional tagging methods. Our approach, in principle, enables analysis of multicomponent mixtures by identifying constituent molecules one at a time. Single molecule sensitivity extends action spectroscopy to rare samples, such as those of extraterrestrial origin or to reactive reaction intermediates formed at number densities that are too low for traditional action methods. 生态以及天气Ecology Climate Marine heatwaves are not a dominant driver of change in demersal fishes 海洋热浪不是致使底栖鱼类变迁的重要要素 ▲ 作者：Alexa L. Fredston, William W. L. Cheung, Thomas L. Fr licher, Zo J. Kitchel, Aurore A. Maureaud, James T. Thorson, Arnaud Auber, Bastien M rigot, Juliano Palacios-Abrantes, Maria Lourdes D. Palomares, Laur ne Pecuchet, Nancy L. Shackell Malin L. Pinsky ▲ 链接： https://www.nature.com/articles/s41586-023-06439-0 ▲ 择要： 近几十年来，海洋热浪与负面生态效应有关。假如海洋热浪常常致使群落重组以及鱼类生物量瓦解，那末对于生态体系、渔业以及人类社区来讲，后果多是灾害性的。然而，海洋热浪对于鱼类生物量或者群落构成的负面影响水平，以至它们的影响是否可以与天然以及采样变同性区别开来，仍不清晰。研究者经由过程阐发从北美以及欧洲超过亚热带到北极的年夜陆架生态体系的82322份持久科学查询拜访样本，研究了1993年至2019年248次海底热浪对于海洋鱼类的影响。 研究者注解海洋热浪对于鱼类生物量的影响凡是很小，不克不及与天然以及采样变同性区别开来。此外，于这些生态体系中，海洋热浪其实不老是与热带化（暖缘物种的增长）或者去丛林化（冷缘物种的削减）相干。虽然海洋热浪事后偶然会呈现生物量急剧降落的环境，但这只是破例，并不是遍及征象。于海洋生态体系高度多变的配景下，海洋热浪并无鞭策撑持世界上很多最年夜以及最具出产力渔业的鱼类群落的生物质变化或者群落更替。 ▲ Abstract： Marine heatwaves have been linked to negative ecological effects in recent decades. If marine heatwaves regularly induce co妹妹unity reorganization and biomass collapses in fishes, the consequences could be catastrophic for ecosystems, fisheries and human co妹妹unities. However, the extent to which marine heatwaves have negative impacts on fish biomass or co妹妹unity composition, or even whether their effects can be distinguished from natural and sampling variability, remains unclear. We investigated the effects of 248 sea-bottom heatwaves from 1993 to 2019 on marine fishes by analysing 82,322 hauls (samples) from long-term scientific surveys of continental shelf ecosystems in North America and Europe spanning the subtropics to the Arctic. Here we show that the effects of marine heatwaves on fish biomass were often minimal and could not be distinguished from natural and sampling variability. Furthermore, marine heatwaves were not consistently associated with tropicalization (gain of warm-affiliated species) or deborealization (loss of cold-affiliated species) in these ecosystems. Although steep declines in biomass occasionally occurred after marine heatwaves, these were the exception, not the rule. Against the highly variable backdrop of ocean ecosystems, marine heatwaves have not driven biomass change or co妹妹unity turnover in fish co妹妹unities that support many of the world s largest and most productive fisheries. Persistent equatorial Pacific iron limitation under ENSO forcing ENSO强制下赤道承平洋铁的连续限定 ▲ 作者：Thomas J. Browning, Mak A. Saito, Shungudzemwoyo P. Garaba, Xuechao Wang, Eric P. Achterberg, C. Mark Moore, Anja Engel, Matthew R. Mcllvin, Dawn Moran, Daniela Voss, Oliver Zielinski Alessandro Tagliabue ▲ 链接： https://www.nature.com/articles/s41586-023-06439-0 ▲ 择要： 今朝预估的海洋净低级出产力对于天气变迁的相应高度不确定。相干模式研究注解，低纬度承平洋浮游动物养分限定的天气敏感性起着至关主要的作用，但这一点很少遭到不雅测的约束。研究者发明物理强制的变迁经由过程多个厄尔尼诺/南边涛动(ENSO)周期驱动赤道承平洋铁限定强度的联贯颠簸，但开始进的天气模子高估了两倍。 该评估起首联合了野外养分增添试验、卵白质组学以及水上高光谱辐射丈量，注解浮游动物对于铁限定的心理反映致使叶绿素尺度化浮游动物荧光的约莫三倍变迁。 然后，研究者哄骗持续18年的卫星荧光记载来量化天气惹起的养分限定变异。这类气候前提限定为确定净低级出产力对于天气变迁模子猜测的实际性提供了一种强无力的要领。 ▲ Abstract： Projected responses of ocean net primary productivity to climate change are highly uncertain1. Models suggest that the climate sensitivity of phytoplankton nutrient limitation in the low-latitude Pacific Ocean plays a crucial role, but this is poorly constrained by observations. Here we show that changes in physical forcing drove coherent fluctuations in the strength of equatorial Pacific iron limitation through multiple El Ni o/Southern Oscillation (ENSO) cycles, but that this was overestimated twofold by a state-of-the-art climate model. Our assessment was enabled by first using a combination of field nutrient-addition experiments, proteomics and above-water hyperspectral radiometry to show that phytoplankton physiological responses to iron limitation led to approximately threefold changes in chlorophyll-normalized phytoplankton fluorescence. We then exploited the 18-year satellite fluorescence record to quantify climate-induced nutrient limitation variability. Such synoptic constraints provide a powerful approach for benchmarking the realism of model projections of net primary productivity to climate changes.出格声明：本文转载仅仅是出在流传信息的需要，其实不象征着代表本消息网不雅点或者证明其内容的真实性；如其他媒体、消息网或者小我私家从本消息网转载使用，须保留本消息网注明的“来历”，并自大版权等法令义务；作者假如不但愿被转载或者者接洽转载稿费等事宜，请与咱们联系。/天博
