自然（20221215出版）一周论文导读

　　编译 | 李言
　　Nature , 15 December 2022, Volume 612 Issue 7940
　　《自然》 2022年12月15日，第612卷7940期
　　物理学 Physics
　　Disorder-assisted assembly of strongly correlated fluids of light
　　强相关光流体的无序辅助组装
　　▲ 作者：Brendan Saxberg, Andrei Vrajitoarea, Gabrielle Roberts, Margaret G. Panetta, Jonathan Simon & David I. Schuster
　　▲ 链接：
　　https://www.nature.com/articles/s41586-022-05357-x
　　▲ 摘要：
　　在此，我们通过结合粒子组装和绝热制备，在Bose–Hubbard电路中构建了光的低熵量子流体。我们将单个光子注入到一个特征态是已知的并且是局域的、无序的晶格中，然后绝热去除这种无序，使量子涨落将光子融化成流体。
　　通过利用我们的平台，我们首先构建和表征任意单粒子盒态来对这种点阵熔化技术进行基准测试，然后组装多粒子强相关流体。通过单点断层扫描进行的点间纠缠测量表明，流体中的粒子离域。而两体密度相关测量表明，它们也相互避开，揭示了Tonks–Girardeau气体的Friedel振荡特征。
　　▲ Abstract：
　　Here we construct low-entropy quantum fluids of light in a Bose–Hubbard circuit by combining particle-by-particle assembly and adiabatic preparation. We inject inpidual photons into a disordered lattice for which the eigenstates are known and localized, then adiabatically remove this disorder, enabling quantum fluctuations to melt the photons into a fluid. Using our platform, we first benchmark this lattice melting technique by building and characterizing arbitrary single-particle-in-a-box states, then assemble multiparticle strongly correlated fluids. Intersite entanglement measurements performed through single-site tomography indicate that the particles in the fluid delocalize, whereas two-body density correlation measurements demonstrate that they also avoid one another, revealing Friedel oscillations characteristic of a Tonks–Girardeau gas.
　　Majorana-like Coulomb spectroscopy in the absence of zero-bias peaks
　　无零偏峰时的类马约拉纳库仑光谱
　　▲ 作者：Marco Valentini, Maksim Borovkov, Elsa Prada, Sara Martí-Sánchez, Marc Botifoll, Andrea Hofmann, Jordi Arbiol, Ramón Aguado, Pablo San-Jose & Georgios Katsaros
　　▲ 链接：
　　https://www.nature.com/articles/s41586-022-05382-w
　　▲ 摘要：
　　在此，我们设计了一种实验方案，允许我们通过正常引线的可调结调整其充电能量，在同一混合量上执行两种类型的测量。该方法通过检测非阻塞传输中库仑阻塞（CB）光谱与零偏压峰之间的一致性，减少了马约拉纳检测的模糊性。
　　具体来说，我们在InAs/Al杂化纳米线中观察到结依赖、偶奇调制的单电子CB峰，在隧道光谱中没有伴随低偏压峰。我们在低能量的纵向限制态提供了一个理论解释的实验观测，而不是重叠马约拉纳模式。
　　▲ Abstract：
　　Here we devise an experimental protocol that allows us to perform both types of measurement on the same hybrid island by adjusting its charging energy via tunable junctions to the normal leads. This method reduces ambiguities of Majorana detections by checking the consistency between CB spectroscopy and zero-bias peaks in non-blockaded transport. Specifically, we observe junction-dependent, even–odd modulated, single-electron CB peaks in InAs/Al hybrid nanowires without concomitant low-bias peaks in tunnelling spectroscopy. We provide a theoretical interpretation of the experimental observations in terms of low-energy, longitudinally confined island states rather than overlapping Majorana modes.
　　材料科学 Materials Science
　　Anomalous thermal transport under high pressure in boron arsenide
　　高压下砷化硼的异常热传导
　　▲ 作者：Suixuan Li, Zihao Qin, Huan Wu, Man Li, Martin Kunz, Ahmet Alatas, Abby Kavner & Yongjie Hu
　　▲ 链接：
　　https://www.nature.com/articles/s41586-022-05381-x
　　▲ 摘要：
　　在此，我们报告新发现的半导体晶体砷化硼的原位热传导测量，并观察到热导率的异常压力依赖性。我们使用超快光学、拉曼光谱和非弹性x射线散射测量来检查光学和声学分支的声子带结构演化，以及在高达32GPa的不同温度和压力下的热导率。
　　利用原子理论，我们将异常高压行为归因于独特声子带结构所固有的相互作用高阶非谐性物理的竞争热传导产生。
　　▲ Abstract：
　　Here we report in situ thermal transport measurements in the newly discovered semiconductor crystal boron arsenide, and observe an anomalous pressure dependence of the thermal conductivity. We use ultrafast optics, Raman spectroscopy and inelastic X-ray scattering measurements to examine the phonon bandstructure evolution of the optical and acoustic branches, as well as thermal conductivity under varied temperatures and pressures up to 32 gigapascals. Using atomistic theory, we attribute the anomalous high-pressure behaviour to competitive heat conduction channels from interactive high-order anharmonicity physics inherent to the unique phonon bandstructure.
　　地球科学 Geoscience
　　Wetland emission and atmospheric sink changes explain methane growth in 2020
　　湿地排放和大气汇变化解释了2020年甲烷的增长
　　▲ 作者：Shushi Peng, Xin Lin, Rona L. Thompson, Yi Xi, Gang Liu, Didier Hauglustaine, Xin Lan, Benjamin Poulter, Michel Ramonet, Marielle Saunois, Yi Yin, Zhen Zhang, Bo Zheng & Philippe Ciais
　　▲ 链接：
　　https://www.nature.com/articles/s41586-022-05447-w
　　▲ 摘要：
　　在此，我们量化了2020年与2019年相比甲烷来源及其大气汇的变化。我们发现，在全球范围内，人为排放总量每年减少1.2±0.1太克甲烷，火灾排放每年减少6.5±0.1 太克甲烷，湿地排放每年增加6.0±2.3 太克甲烷每年。
　　与2019年相比，对流层氢氧根浓度下降了1.6%±0.2%，主要原因是在大流行封控期间，人为氮氧化物排放减少，导致相对应的对流层游离臭氧减少。根据大气逆温，我们还推断出2020年全球净排放量相对于2019年增加了每年6.9±2.1 太克甲烷，与OH反应的全球甲烷去除率减少了每年7.5±0.8 太克甲烷。
　　因此，我们将2020年相对于2019年的甲烷增长率异常归因于较低的OH汇（53±10%）和较高的自然排放（47±16%），主要来自湿地。与此前的研究一致，我们的研究结果表明，湿地甲烷排放对气候变暖和变湿较为敏感，并可能在未来发挥正反馈机制的作用。
　　▲ Abstract：
　　Here we quantify changes in methane sources and in its atmospheric sink in 2020 compared with 2019. We find that, globally, total anthropogenic emissions decreased by 1.2 ± 0.1 teragrams of methane per year (Tg CH4 yr−1 , fire emissions decreased by 6.5 ± 0.1 Tg  CH4 yr−1  and wetland emissions increased by 6.0 ± 2.3 Tg  CH4 yr−1 . Tropospheric OH concentration decreased by 1.6 ± 0.2 per cent relative to 2019, mainly as a result of lower anthropogenic nitrogen oxide (NOx) emissions and associated lower free tropospheric ozone during pandemic lockdowns. From atmospheric inversions, we also infer that global net emissions increased by 6.9 ± 2.1 Tg  CH4 yr−1  in 2020 relative to 2019, and global methane removal from reaction with OH decreased by 7.5 ± 0.8 Tg  CH4 yr−1 . Therefore, we attribute the methane growth rate anomaly in 2020 relative to 2019 to lower OH sink (53 ± 10 per cent) and higher natural emissions (47 ± 16 per cent), mostly from wetlands. In line with previous findings, our results imply that wetland methane emissions are sensitive to a warmer and wetter climate and could act as a positive feedback mechanism in the future.
　　Widespread herbivory cost in tropical nitrogen-fixing tree species
　　热带固氮树种广泛的植食成本
　　▲ 作者：Will Barker, Liza S. Comita, S. Joseph Wright, Oliver L. Phillips, Brian E. Sedio & Sarah A. Batterman
　　▲ 链接：
　　https://www.nature.com/articles/s41586-022-05502-6
　　▲ 摘要：
　　在此，我们研究了动物的植食性是否限制了热带森林中的共生固氮。我们评估了固氮树种是否比其他树有更多的植食性，植食是否会带来大量的碳成本，以及高植食性是否是食草动物针对固氮树富含氮的叶子的结果。
　　我们分析了巴拿马43种热带树种的350棵幼苗的1626片叶子，发现：（1）尽管植食性降低了所有幼苗的生长和存活概率，但固氮树的植食性比非固氮树高26%；（2）由于植食性，固氮树的碳机会成本比非固氮树高34%，超过了固氮的代谢成本；（3）固氮树的高植食性不是由高叶氮驱动的。
　　我们的研究结果表明，植食性可能限制热带共生固氮，并可能限制其在缓解热带碳汇氮限制中的作用。
　　▲ Abstract：
　　Here we examine whether herbivory by animals is responsible for limiting symbiotic nitrogen fixation in tropical forests. We evaluate whether nitrogen-fixing trees experience more herbivory than other trees, whether herbivory carries a substantial carbon cost, and whether high herbivory is a result of herbivores targeting the nitrogen-rich leaves of fixers. We analysed 1,626 leaves from 350 seedlings of 43 tropical tree species in Panama and found that: (1) although herbivory reduces the growth and survival of all seedlings, nitrogen-fixing trees undergo 26% more herbivory than non-fixers; (2) fixers have 34% higher carbon opportunity costs owing to herbivory than non-fixers, exceeding the metabolic cost of fixing nitrogen; and (3) the high herbivory of fixers is not driven by high leaf nitrogen. Our findings reveal that herbivory may be sufficient to limit tropical symbiotic nitrogen fixation and could constrain its role in alleviating nitrogen limitation on the tropical carbon sink.
　　动物学 Zoology
　　The pupal moulting fluid has evolved social functions in ants
　　蚂蚁的蛹蜕皮液已经进化出了社会功能
　　▲ 作者：Orli Snir, Hanan Alwaseem, Søren Heissel, Anurag Sharma, Stephany Valdés-Rodríguez, Thomas S. Carroll, Caroline S. Jiang, Jacopo Razzauti & Daniel J. C. Kronauer
　　▲ 链接：
　　https://www.nature.com/articles/s41586-022-05480-9
　　▲ 摘要：
　　在此，我们使用逆向工程方法，揭示了与独居昆虫不同，蚂蚁蛹挤出一种来自蛹蜕皮液的分泌物，富含营养物质、激素和神经活性物质。这种分泌物会引发亲代的照料行为，被成虫迅速清除并消耗。这种行为对蛹的生存至关重要：如果不清除分泌物，蛹就会发生真菌感染并死亡。
　　类似于哺乳动物的乳汁，这种分泌物也是早期幼虫营养的重要来源，如果没有这种液体，幼虫会生长发育不良，导致存活率下降。
　　我们的研究表明，蛹蜕皮液的这种衍生社会功能在蚂蚁中普遍存在。因此，这种分泌物形成了迄今为止在蚂蚁社会中被忽视的核心互动网络的基础，并构成了一个罕见的例子，说明保守的发育过程可以成为提供社会互动的机制基础。这些结果表明蛹蜕皮液在蚂蚁群居性的进化中起着重要作用。
　　▲ Abstract：
　　Here, using a reverse engineering approach, we reveal that unlike solitary insects, ant pupae extrude a secretion derived from the moulting fluid that is rich in nutrients, hormones and neuroactive substances. This secretion elicits parental care behaviour and is rapidly removed and consumed by the adults. This behaviour is crucial for pupal survival; if the secretion is not removed, pupae develop fungal infections and die. Analogous to mammalian milk, the secretion is also an important source of early larval nutrition, and young larvae exhibit stunted growth and decreased survival without access to the fluid. We show that this derived social function of the moulting fluid generalizes across the ants. This secretion thus forms the basis of a central and hitherto overlooked interaction network in ant societies, and constitutes a rare example of how a conserved developmental process can be co-opted to provide the mechanistic basis of social interactions. These results implicate moulting fluids in having a major role in the evolution of ant eusociality.