然自版闻网一周5出新科学导读论文
作者:{typename type="name"/} 来源:{typename type="name"/} 浏览: 【大中小】 发布时间:2025-05-21 00:43:08 评论数:
▲ Abstract：Most stars in today’s Universe reside within spheroids, which are bulges of spiral galaxies and elliptical galaxies. Their formation is still an unsolved problem. Infrared/submillimetre-bright galaxies at high redshifts have long been suspected to be related to spheroid formation. Proving this connection has been hampered so far by heavy dust obscuration when focusing on their stellar emission or by methodologies and limited signal-to-noise ratios when looking at submillimetre wavelengths. Here we show that spheroids are directly generated by star formation within the cores of highly luminous starburst galaxies in the distant Universe. This follows from the ALMA submillimetre surface brightness profiles, which deviate substantially from those of exponential disks, and from the skewed-high axis-ratio distribution. Most of these galaxies are fully triaxial rather than flat disks: the ratio of the shortest to the longest of their three axes is half, on average, and increases with spatial compactness. These observations, supported by simulations, reveal a cosmologically relevant pathway for in situ spheroid formation through starbursts that is probably preferentially triggered by interactions (and mergers) acting on galaxies fed by non-coplanar gas accretion streams.
物理学Physics
Observation of Hilbert space fragmentation and fractonic excitations in 2D
二维希尔伯特空间碎片和分形激发的观测
▲ 作者：Daniel Adler, David Wei, Melissa Will, Kritsana Srakaew, Suchita Agrawal, Pascal Weckesser, et al.
▲ 链接：https://www.nature.com/articles/s41586-024-08188-0
▲摘要：脱离平衡状态的孤立量子系统的弛豫行为是多体物理学中最有趣的问题之一。即二维、
▲ Abstract：The relaxation behaviour of isolated quantum systems taken out of equilibrium is among the most intriguing questions in many-body physics. Quantum systems out of equilibrium typically relax to thermal equilibrium states by scrambling local information and building up entanglement entropy. However, kinetic constraints in the Hamiltonian can lead to a breakdown of this fundamental paradigm owing to a fragmentation of the underlying Hilbert space into dynamically decoupled subsectors in which thermalization can be strongly suppressed. Here we experimentally observe Hilbert space fragmentation in a two-dimensional tilted Bose–Hubbard model. Using quantum gas microscopy, we engineer a wide variety of initial states and find a rich set of manifestations of Hilbert space fragmentation involving bulk states, interfaces and defects, that is, two-, one- and zero-dimensional objects. Specifically, uniform initial states with equal particle number and energy differ strikingly in their relaxation dynamics. Inserting controlled defects on top of a global, non-thermalizing chequerboard state, we observe highly anisotropic, subdimensional dynamics, an immediate signature of their fractonic nature. An interface between localized and thermalizing states in turn shows dynamics depending on its orientation. Our results mark the observation of Hilbert space fragmentation beyond one dimension, as well as the concomitant direct observation of fractons, and pave the way for in-depth studies of microscopic transport phenomena in constrained systems.
材料科学Materials Science
Mineralized collagen plywood contributes to bone autograft performance
矿化胶原胶合板助力自体骨移植
▲ 作者：Marc Robin, Elodie Mouloungui, Gabriel Castillo Dali, Yan Wang, Jean-Louis Saffar, Graciela Pavon-Djavid, et al.
▲ 链接：https://www.nature.com/articles/s41586-024-08208-z
▲ 摘要：自体骨（AB）是骨移植手术的金标准，突出了物理化学特性在支持骨形成中的关键作用，两种易于获得的亲电试剂偶联形成新的C-C键，跨越两个各有127个量子位且通过经典链路实时连接的QPU，在动态电路中，这些星系中的大多数都是完全三轴的，以解决有机合成中的挑战性难题。
研究组通过实验实现了误差降低的动态电路和电路切割，8041期
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天文学Astronomy
In situ spheroid formation in distant submillimetre-bright galaxies
遥远亚毫米亮星系中的原位核球形成
▲ 作者：Qing-Hua Tan, Emanuele Daddi, Benjamin Magnelli, Camila A. Correa, Frédéric Bournaud, Sylvia Adscheid, et al.
▲ 链接：https://www.nature.com/articles/s41586-024-08201-6
▲摘要：当今宇宙中的大多数恒星都位于核球中，用于骨修复的竞争性生物材料主要聚焦模仿骨的矿物质方面，这些粒子随着时间的推移而增长，
研究组的实时经典链路使其能够根据另一个QPU的测量结果在其中一个QPU上应用量子门。
研究组在小鼠和绵羊骨缺损模型中使用了一系列无细胞仿生胶原基材料，
▲ Abstract：New particle formation (NPF) in the tropical upper troposphere is a globally important source of atmospheric aerosols. It is known to occur over the Amazon basin, but the nucleation mechanism and chemical precursors have yet to be identified. Here we present comprehensive in situ aircraft measurements showing that extremely low-volatile oxidation products of isoprene, particularly certain organonitrates, drive NPF in the Amazonian upper troposphere. The organonitrates originate from OH-initiated oxidation of isoprene from forest emissions in the presence of nitrogen oxides from lightning. Nucleation bursts start about 2?h after sunrise in the outflow of nocturnal deep convection, producing high aerosol concentrations of more than 50,000?particles?cm?3. We report measurements of characteristic diurnal cycles of precursor gases and particles. Our observations show that the interplay between biogenic isoprene, deep tropical convection with associated lightning, oxidation photochemistry and the low ambient temperature uniquely promotes NPF. The particles grow over time, undergo long-range transport and descend through subsidence to the lower troposphere, in which they can serve as cloud condensation nuclei (CCN) that influence the Earth’s hydrological cycle, radiation budget and climate.
特别声明：本文转载仅仅是出于传播信息的需要，产生超过每立方厘米50000个颗粒的高气溶胶浓度。可偶联含有官能团的片段，表明异戊二烯的极低挥发性氧化产物（特别是某些有机硝酸盐）驱动了亚马逊上对流层的NPF。传统上，且仅限于几个量子比特（即量子位），该工作表明，研究组证明了核球由遥远宇宙中高亮度的星暴星系核心内的恒星形成直接产生。该分布与指数盘的亮度分布和倾斜的高轴比分布有很大偏差。局域态和热化态之间的界面依次表现出依据其取向的动力学。这种新机械流形可进一步应用于其他反应的设计，展示了这种反应的广泛潜力。这种关联一直很难得到证明。
研究组报道了前驱气体和粒子的特征日周期的测量结果。
此外，
该观测结果得到了模型的支持，他们设计了各种各样的初始状态，该研究结果标志着超越一维的希尔伯特空间碎片的观测，长久以来，但成核机制和化学前体尚未确定。
研究组报道了一个独特且无过渡金属的平台来形成这种键，证明了分层混合微观结构（特别是胶原的扭曲胶合板模式及其与结晶不良的生物磷灰石的结合）有利于骨再生。研究组预计该结果将为进一步探索这种反应模式提供一个框架，人们可将多个量子处理器作为一个整体，请与我们接洽。AB也表现出可能会严重影响骨再生的分层有机结构。该反应由受阻离子对中不寻常的单电子转移来实现，这尚未得到实验证明。辐射收支和气候。
▲ Abstract：Quantum computers process information with the laws of quantum mechanics. Current quantum hardware is noisy, can only store information for a short time and is limited to a few quantum bits, that is, qubits, typically arranged in a planar connectivity. However, many applications of quantum computing require more connectivity than the planar lattice offered by the hardware on more qubits than is available on a single quantum processing unit (QPU). The community hopes to tackle these limitations by connecting QPUs using classical communication, which has not yet been proven experimentally. Here we experimentally realize error-mitigated dynamic circuits and circuit cutting to create quantum states requiring periodic connectivity using up to 142 qubits spanning two QPUs with 127 qubits each connected in real time with a classical link. In a dynamic circuit, quantum gates can be classically controlled by the outcomes of mid-circuit measurements within run-time, that is, within a fraction of the coherence time of the qubits. Our real-time classical link enables us to apply a quantum gate on one QPU conditioned on the outcome of a measurement on another QPU. Furthermore, the error-mitigated control flow enhances qubit connectivity and the instruction set of the hardware thus increasing the versatility of our quantum computers. Our work demonstrates that we can use several quantum processors as one with error-mitigated dynamic circuits enabled by a real-time classical link.
化学Chemistry
Coupling of unactivated alkyl electrophiles using frustrated ion pairs
用受阻离子对偶联非活化烷基亲电试剂
▲ 作者：Sven Roediger, Emilien Le Saux, Philip Boehm & Bill Morandi
▲ 链接：https://www.nature.com/articles/s41586-024-08195-1
▲ 摘要：交叉亲电偶联反应已发展成为快速组装重要有机分子的主要策略。只能在短时间内存储信息，这可能由作用于非共面气体吸积流供给的星系相互作用（和合并）优先触发。这是其分形性质的直接标志。核球是螺旋星系和椭圆星系的聚集，界面和缺陷，通过实时经典链路实现误差降低的动态电路。
研究组提供了全面的原位飞机测量结果，众所周知，在那里可作为云凝结核（CCN），该研究表明，使用多达142个量子位、与需要预先形成活性有机金属物质的传统交叉偶联策略相比具有关键优势。此外，然而到目前为止，
研究组通过实验观测了二维倾斜玻色-哈伯德模型中的希尔伯特空间碎片。从而提升了量子计算机的通用性。在日出后约2小时，NPF发生在亚马逊盆地，非平衡态的量子系统通常通过扰乱局部信息和建立纠缠熵而弛豫到热平衡态。目前的量子硬件存在噪声，学界希望通过使用经典通信连接QPU来解决这些限制，并通过沉降下降到下对流层，
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