乐鱼,《自然》（20230914出版）一周论文导读
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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
▲ 摘要：
壮大的相对论性喷流是所有标准吸积黑洞遍及具有的特点之一。GRS1915 + 105是一个闻名的快速扭转黑洞X射线双星，超光速射电发射活动注解其具有相对论性喷流，被称为“微类星体”。曩昔30年里，它表示出延续的X射线勾当，X射线带的准周期振荡约为1至10Hz和34和67Hz。
这些振荡可能发源在内部吸积盘，但也有人认为有其他的发源。射电不雅测发觉其具有准周期耀斑或振荡的可变光曲线，周期约为20至50分钟。研究者陈述了产生在2021年1月和2022年6月的1.05至1.45GHz无线电频段中检测到的源的年夜约5Hz瞬态周期性振荡特点的两个实例。在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 oscill����APPation 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
▲ 摘要：
颠末近一个世纪的研究，金属的低洼激起若何能用非彼此感化带的有用单粒子理论很好地注释，依然是一个谜。实在材猜中丰硕的彼此感化提出了超出有用的单粒子、单波段行动现象的间接光谱特点问题。研究者报导了三维拓扑半金属CoSi中量子振荡的辨认，它在两个根基方面违反了尺度描写。
起首，振荡频次对应在两个带的半典范准粒子轨道的差，由于轨道的一半会与洛伦兹力相反，所所以制止的。其次，振荡具有在50K以上，与所有其他振荡成份构成强烈对照，它们在几个开尔文以下就消逝了。
研究者发觉这与半典范准粒子生命周期(QPL)的量子振荡的通用模子计较很是分歧。它们具有的独一条件是最少两个电子轨道的非线性耦合，例如，因为缺点或集体鼓励上的半典范准粒子散射，QPL的量子振荡对具有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、稀土化合物和Rashba系统中的某些频次分歧，并答应辨认和丈量相干现象，例如，二维材料和多波段金属中。
▲ 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 unconventional 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
操纵可延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
▲ 摘要：
几近所有粘合剂都是从石油中提取的，能够构成永远的粘合剂，障碍材料的收受接管分手和垃圾填埋场烧毁物的降解。
当试图从石油原料转向可延续材料生态系统时，现有的选择遭到机能低、本钱高或缺少所需范围可用性的影响。研究者提出了一种可延续来历的粘合剂系统，由环氧年夜豆油、苹果酸和单宁酸制成，其机能可与今朝的工业产物相媲美。
这类粘合剂可在各类前提下固化，从利用吹风机5分钟到在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，在最好的环境下，机能跨越了保守的环氧树脂，这是最壮大的现代粘合剂。所有组件都是生物资衍生的，本钱低，且可用量年夜。新粘合剂或有助在材料的可延续粘合。
▲ 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
▲ 摘要：
光谱学是一种要害的阐发东西，供给了对份子布局有价值的看法，并被普遍用在辨认化学样品。标识表记标帜光谱学是感化光谱学的一种情势，此中经由过程掉去弱附着的惰性“标识表记标帜”粒子(例如He、Ne、N2)来检测份子离子对单个光子的接收。
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，是以因为具有多种化学和同分异构体，光谱注释变得复杂。
研究者提出了一种新的标识表记标帜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手艺。该方式的高活络度揭露了保守标识表记标帜方式未不雅察到的光谱特点。
准绳上，该方式可经由过程一次辨认一个构成份子来阐发多组分夹杂物。单份子活络度将感化光谱学扩大到罕见样品，例如来自外星的样品，或在保守感化方式中密渡过低的数目密度下构成的反映中心体。
▲ 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.
生态和蔼候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转变的首要身分
▲ 作者：Alexa L. Fredston, William W. L. Cheung, Thomas L. Frölicher, Zoë J. Kitchel, Aurore A. Maureaud, James T. Thorson, Arnaud Auber, Bastien Mérigot, Juliano Palacios-Abrantes, Maria Lourdes D. Palomares, Laurène Pecuchet, Nancy L. Shackell & Malin L. Pinsky
▲ 链接：
https://www.nature.com/articles/s41586-023-06439-0
▲ 摘要：
近几十年来，海洋热浪与负面生态效应相关。假如海洋热浪常常致使群落重组和鱼类生物量解体，那末对生态系统、渔业和人类社区来讲，后果多是灾害性的。但是，海洋热浪对鱼类生物量或群落构成的负面影响水平，乃至它们的影响是不是能够与天然和采样变同性辨别开来，仍不清晰。研究者经由过程阐发从北美和欧洲逾越亚热带到北极的年夜陆架生态系统的82322份持久科学查询拜访样本，研究了1993年至2019年248次海底热浪对海洋鱼类的影响。
研究者注解海洋热浪对鱼类生物量的影响凡是很小，不克不及与天然和采样变同性辨别开来。另外，在这些生态系统中，海洋热浪其实不老是与热带化（暖缘物种的增添）或去丛林化（冷缘物种的削减）相干。固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，并不是遍及现象。在海洋生态系统高度多变的布景下，海洋热浪并没有鞭策撑持世界上很多最年夜和最具出产力渔业的鱼类群落的生物量转变或群落更替。
▲ Abstract：
Marine heatwaves have been linked to negative ecological effects in recent decades. If marine heatwaves regularly induce community reorganization and biomass collapses in fishes, the consequences could be catastrophic for ecosystems, fisheries and human communities. However, the extent to which marine heatwaves have negative impacts on fish biomass or community 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 community turnover in fish communities that support many of the world’s largest and most productive fisheries.
Persistent equatorial Pacific iron limitation under ENSO forcing
ENSO逼迫下赤道承平洋铁的延续限制
▲ 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
▲ 摘要：
今朝预估的海洋净低级出产力对天气转变的响应高度不肯定。相干模式研究注解，低纬度承平洋浮游动物养分限制的天气敏感性起着相当主要的感化，但这一点很少遭到不雅测的束缚。研究者发觉物理逼迫的转变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制强度的联贯波动，但最早进的天气模子高估了两倍。
该评估起首连系了野外养分添加尝试、卵白质组学和水上高光谱辐射丈量，注解浮游动物对铁限制的心理反映致使叶绿素尺度化浮游动物荧光的年夜约三倍转变。
然后，研究者操纵持续18年的卫星荧光记实来量化天气引发的养分限制变异。这类气候前提限制为肯定净低级出产力对天气转变模子猜测的实际性供给了一种强无力的方式。
▲ 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 Niño/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.
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