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编译 | 冯维维 Nature,做作周论 Volume 622 Issue 7984, 26 October 2023 《做作》第622卷，7984期 ，出书2023年10月26日 ?文导 天体物理学Astrophysics Confirmation and refutation of very luminous galaxies in the early Universe 韦布望远镜审核到早期宇宙璀璨星系 ▲ 作者 ：Pablo Arrabal Haro, Mark Dickinson, Steven L. Finkelstein, Jeyhan S. Kartaltepe, Callum T. Donnan, Denis Burgarella, Jorge A. Zavala, etc. ▲ 链接： https://www.nature.com/articles/s41586-023-06521-7 ▲ 摘要 ： 在宇宙历史的最后5亿年里 ，第一批恒星以及星系组成 ，做作周论给宇宙播下了重元素，出书并最终重新电离了星系间介质。文导詹姆斯·韦布太空望远镜审核发现了使人惊惶的做作周论大批早期恒星组成星系候选者 ，凭证多波段光度法估量 ，出书其距离（红移 ，文导z）大到z≈16 ，做作周论远超JWST以前的出书限度。 尽管这样的文导光度红移艰深为安妥的，但它们可能蒙受简并以及无意偶尔的做作周论苦难性过错。需要光谱丈量来验证这些源头 ，出书并坚贞地量化可能约束星系组成模子以及宇宙学的文导物理特色。 钻研者揭示了韦布光谱，证明了两个颇为璀璨的星系的红移为z>11 ，并证明了另一个候选星系的红移为z≈16，而非此前以为的z = 4.9 ，它们具备不艰深的星云线发射以及灰尘变红的组合 ，与更遥远天体的颜色相似 。 这些服从增强了早期快捷组成颇为璀璨星系的证据 ，同时也夸张了光谱验证的需要性 。大批璀璨的早期星系或者表明之后星系组成模子的缺陷 ，或者与个别以为在前期建树的物理性子（如恒星初始品质函数）的倾向。 ▲ Abstract： During the first 500 million years of cosmic history, the first stars and galaxies formed, seeding the Universe with heavy elements and eventually reionizing the intergalactic medium Observations with the James Webb Space Telescope (JWST) have uncovered a surprisingly high abundance of candidates for early star-forming galaxies, with distances (redshifts, z), estimated from multiband photometry, as large as z?≈?16, far beyond pre-JWST limits. Although such photometric redshifts are generally robust, they can suffer from degeneracies and occasionally catastrophic errors. Spectroscopic measurements are required to validate these sources and to reliably quantify physical properties that can constrain galaxy formation models and cosmology. Here we present JWST spectroscopy that confirms redshifts for two very luminous galaxies with z > 11, and also demonstrates that another candidate with suggested z ≈ 16 instead has z = 4.9, with an unusual combination of nebular line emission and dust reddening that mimics the colours expected for much more distant objects. These results reinforce evidence for the early, rapid formation of remarkably luminous galaxies while also highlighting the necessity of spectroscopic verification. The large abundance of bright, early galaxies may indicate shortcomings in current galaxy formation models or deviations from physical properties (such as the stellar initial mass function) that are generally believed to hold at later times. Geophysical evidence for an enriched molten silicate layer above Mars’s core 火核外层存在丰硕熔融硅酸盐层 ▲ 作者 ：Henri Samuel, Mélanie Drilleau, Attilio Rivoldini, Zongbo Xu, Quancheng Huang, Rapha?l F. Garcia, Vedran Leki?, Jessica C. E. Irving, James Badro, Philippe H. Lognonné, James A. D. Connolly, Taichi Kawamura, Tamara Gudkova & William B. Banerdt ▲ 链接 ： https://www.nature.com/articles/s41586-023-06601-8 ▲ 摘要 ： 在火星上探测到的深反射S波判断出火核的巨细为1830±40km，但这需要的轻元素含量与试验岩石学的限度不相容 。 一种假如是火星地幔的成份是平均的 ，这与最近丈量到的沿中间-地幔领土衍射的颇为飞快转达的P波不不同 。 另一种假如是 ，火星的地幔是不屈均的 ，这是早期岩浆陆地凝妄想成一个富含铁以及产热元素的基底层的服从 。这种富集导致在岩心上方组成熔融硅酸盐层 ，由部份熔融层拆穿困绕 。 钻研表明这种妄想与所有地球物理数据兼容 ，特意是（1）深反射以及衍射地幔地震相位；（2）地震频率上的弱剪切衰减；（3）火星在火卫一潮汐上的耗散性子 。 在这个场景中 ，火核的巨细为1650±20km ，象征着其密度为6.5 g cm?3 ，比从前的估量大5%~8% ，而且可能用比从前所需的更少 、更少的合金轻元始终声名，其数目与试验以及宇宙化学的限度相不同 。最后 ，层状地幔妄想需要外部源来发生记着实火星地壳中的磁信号 。 ▲ Abstract ： The detection of deep reflected S waves on Mars inferred a core size of 1,830 ± 40 km, requiring light-element contents that are incompatible with experimental petrological constraints. This estimate assumes a compositionally homogeneous Martian mantle, at odds with recent measurements of anomalously slow propagating P waves diffracted along the core–mantle boundary. An alternative hypothesis is that Mars’s mantle is heterogeneous as a consequence of an early magma ocean that solidified to form a basal layer enriched in iron and heat-producing elements. Such enrichment results in the formation of a molten silicate layer above the core, overlain by a partially molten layer. Here we show that this structure is compatible with all geophysical data, notably (1) deep reflected and diffracted mantle seismic phases, (2) weak shear attenuation at seismic frequency and (3) Mars’s dissipative nature at Phobos tides. The core size in this scenario is 1,650 ± 20 km, implying a density of 6.5 g cm?3, 5–8% larger than previous seismic estimates, and can be explained by fewer, and less abundant, alloying light elements than previously required, in amounts compatible with experimental and cosmochemical constraints. Finally, the layered mantle structure requires external sources to generate the magnetic signatures recorded in Mars’s crust. 物理学Physics A superconducting nanowire single-photon camera with 400,000 pixels 40万像素的超导纳米线单光子相机 ▲ 作者 ：B. G. Oripov, D. S. Rampini, J. Allmaras, M. D. Shaw, S. W. Nam, B. Korzh & A. N. McCaughan ▲ 链接 ： https://www.nature.com/articles/s41586-023-06550-2 ▲ 摘要 ： 以前50年，超导探测器的普遍运用为探测单薄的电磁信号提供了卓越的锐敏度以及速率。这些探测器可能在颇为低的温度下使命，发生最小的过剩噪音 ，是测试非部份性子 、钻研暗物资 、绘制早期宇宙以及实施量子合计以及通讯的事实抉择。 可是 ，尽管它们具备吸引人的特色 ，但当初尚未大规模的超导相机——纵然是最大的演示也从未逾越20,000像素 。对于超导纳米线单光子探测器（SNSPDs）来说特意如斯 。 钻研者开拓了一款40万像素SNSPD相机 ，比当初的技术水平后退了400倍 。其成像地域不搜罗辅助电路 ，架构的可扩展性远远逾越了当初的演示 ，为在普遍的电磁频谱规模内具备挨近不同检测功能的大画幅超导相机摊平了道路 。 ▲ Abstract： For the past 50 years, superconducting detectors have offered exceptional sensitivity and speed for detecting faint electromagnetic signals in a wide range of applications. These detectors operate at very low temperatures and generate a minimum of excess noise, making them ideal for testing the non-local nature of reality, investigating dark matter, mapping the early universe and performing quantum computation and co妹妹unication. Despite their appealing properties, however, there are at present no large-scale superconducting cameras—even the largest demonstrations have never exceeded 20,000?pixels15. This is especially true for superconducting nanowire single-photon detectors (SNSPDs). These detectors have been demonstrated with system detection efficiencies of 98.0%, sub-3-ps timing jitter, sensitivity from the ultraviolet21 to the mid-infrared and microhertz dark-count rates3, but have never achieved an array size larger than a kilopixel. Here we report on the development of a 400,000-pixel SNSPD camera, a factor of 400 improvement over the state of the art. The imaging area contains no ancillary circuitry and the architecture is scalable well beyond the present demonstration, paving the way for large-format superconducting cameras with near-unity detection efficiencies across a wide range of the electromagnetic spectrum. Dipolar quantum solids emerging in a Hubbard quantum simulator 哈伯德量子模拟器泛起偶极量子固体 ▲ 作者 ：Lin Su, Alexander Douglas, Michal Szurek, Robin Groth, S. Furkan Ozturk, Aaron Krahn, Anne H. Hébert, Gregory A. Phelps, Sepehr Ebadi, Susannah Dickerson, Francesca Ferlaino, Ognjen Markovi? & Markus Greiner ▲ 链接 ： https://www.nature.com/articles/s41586-023-06614-3 ▲ 摘要 ： 在量子力学多体零星中，长程以及各向异性相互熏染增长了丰硕的空间妄想 ，并可能导致量子挫折，从而发生大批重大的 、强相关的量子相 。远距离相互熏染在做作界中起侧紧张熏染；可是 ，晶格零星的量子模拟在很大水平上无奈实现这种相互熏染 。 运用极性份子 、里德伯原子 、光学空腔或者磁性原子探究短途相互熏染晶格零星的探究正在妨碍 。 钻研者运用超冷磁性铒原子，在具备远距离偶极相互熏染的强相关晶格零星中实现为了新的量子相 。当他们将偶极相互熏染调解为零星中主要的能量尺度时 ，审核到从超流体到偶极量子固体的量子相变 ，钻研者运用带手风琴晶格的量子气体显微镜直接检测到这一点。经由偶极子取向操作相互熏染的各向异性 ，可能实现多种条纹有序态 。 此外 ，经由非绝热跃迁 ，钻研者审核到一系列亚稳条纹有序态的泛起 。钻研表明，运用光学晶格中的短途偶极相互熏染可能实现新的强相关量子相 ，为具备短途以及各向异性相互熏染的普遍晶格模子的量子模拟掀开了大门 。 ▲ Abstract ： In quantum mechanical many-body systems, long-range and anisotropic interactions promote rich spatial structure and can lead to quantum frustration, giving rise to a wealth of complex, strongly correlated quantum phases1. Long-range interactions play an important role in nature; however, quantum simulations of lattice systems have largely not been able to realize such interactions. A wide range of efforts are underway to explore long-range interacting lattice systems using polar molecules, Rydberg atoms, optical cavities or magnetic atoms. Here we realize novel quantum phases in a strongly correlated lattice system with long-range dipolar interactions using ultracold magnetic erbium atoms. As we tune the dipolar interaction to be the dominant energy scale in our system, we observe quantum phase transitions from a superfluid into dipolar quantum solids, which we directly detect using quantum gas microscopy with accordion lattices. Controlling the interaction anisotropy by orienting the dipoles enables us to realize a variety of stripe-ordered states. Furthermore, by transitioning non-adiabatically through the strongly correlated regime, we observe the emergence of a range of metastable stripe-ordered states. This work demonstrates that novel strongly correlated quantum phases can be realized using long-range dipolar interactions in optical lattices, opening the door to quantum simulations of a wide range of lattice models with long-range and anisotropic interactions. A microfluidic transistor for automatic control of liquids 一种用于液体自动操作的微流控晶体管 ▲ 作者 ：Kaustav A. Gopinathan, Avanish Mishra, Baris R. Mutlu, Jon F. Edd & Mehmet Toner ▲ 链接 ： https://www.nature.com/articles/s41586-023-06517-3 ▲ 摘要 ： 微流体技术在份子生物学、分解化学 、诊断学以及机关工程等规模取患了清晰妨碍 。可是 ，临时以来 ，该规模不断急切需要以电子电路的精度 、模块化以及可扩展性来操作流体以及悬浮物 。 钻研者运用流体的行动限度天气来开拓一种可能比例淘汰的微流体元件，其流量—压力特色残缺相似于电子晶体管的电流-电压特色 。他们运用该微流控晶体管直接将根基电子电路转换为流控域 ，搜罗缩漂亮 ，调节器 ，电平移位器 ，逻辑门以及锁存器 。 他们还散漫这些构建块来建树更重大的流体操作器 ，如计时器以及时钟。 最后 ，钻研者揭示了一个粒子调配器电路 ，它可能感知单个悬浮粒子 ，实施信号处置 ，并响应地以判断性的方式操作每一个粒子的行动 ，而不需要电子器件 。 经由运用大批的电子电路妄想 ，基于微流体晶体管的电路使流体自动操作器可以为芯片上的试验室平台操作液体以及单个悬浮颗粒 。 ▲ Abstract ： Microfluidics have enabled notable advances in molecular biology, synthetic chemistry, diagnostics and tissue engineering. However, there has long been a critical need in the field to manipulate fluids and suspended matter with the precision, modularity and scalability of electronic circuits. Here we exploit the fluidic phenomenon of flow limitation to develop a microfluidic element capable of proportional amplification with flow–pressure characteristics completely analogous to the current–voltage characteristics of the electronic transistor. We then use this microfluidic transistor to directly translate fundamental electronic circuits into the fluidic domain, including the amplifier, regulator, level shifter, logic gate and latch. We also combine these building blocks to create more complex fluidic controllers, such as timers and clocks. Finally, we demonstrate a particle dispenser circuit that senses single suspended particles, performs signal processing and accordingly controls the movement of each particle in a deterministic fashion without electronics. By leveraging the vast repertoire of electronic circuit design, microfluidic-transistor-based circuits enable fluidic automatic controllers to manipulate liquids and single suspended particles for lab-on-a-chip platforms. 化学Chemistry Geminal-atom catalysis for cross-coupling 交织偶联的双原子催化 ▲ 作者 ：Xiao Hai, Yang Zheng, Qi Yu, Na Guo, Shibo Xi, Javier Pérez-Ramírez, Jiong Lu, etc. ▲ 链接： https://www.nature.com/articles/s41586-023-06529-z ▲ 摘要 ： 单原子催化剂（SACs）具备清晰的活性位点，使其成为有机分解规模的潜在兴趣点。可是 ，由于空间情景以及电子量子态的限度 ，这些晃动在固体载体上的单核金属物种的妄想可能不是催化重大份子转化的最佳抉择 。钻研者报道了一类非均相双原子催化剂（GACs） ，它们以特定的配位以及空间挨近对于单原子位点妨碍配对于 。 原位表征以及量籽实际钻研表明 ，这种交织偶联的动态历程是由两种差距的反映物在双金属位点的吸附引起的 ，使患上均偶联不可行。GACs的这些固有优势使其可能组装具备多个配位位点的杂环 ，具备空间窒息的支架以及具备高特异性以及晃动活性的药物 。淘汰试验以及转化为不断流表明普遍适用于详尽化学品的制作。 ▲ Abstract： Single-atom catalysts (SACs) have well-defined active sites, making them of potential interest for organic synthesis. However, the architecture of these mononuclear metal species stabilized on solid supports may not be optimal for catalysing complex molecular transformations owing to restricted spatial environment and electronic quantum states. Here we report a class of heterogeneous geminal-atom catalysts (GACs), which pair single-atom sites in specific coordination and spatial proximity. In situ characterization and quantum-theoretical studies show that such a dynamic process for cross-coupling is triggered by the adsorption of two different reactants at geminal metal sites, rendering homo-coupling unfeasible. These intrinsic advantages of GACs enable the assembly of heterocycles with several coordination sites, sterically congested scaffolds and pharmaceuticals with highly specific and stable activity. Scale-up experiments and translation to continuous flow suggest broad applicability for the manufacturing of fine chemicals. |