编译 | 未玖Nature, 5 December 2024, Volume 636, Issue 8041《天然》2024年12月5日，第636卷，8041期?地理学AstronomyIn situ spheroid formation in distant submillimetre-bright galaxies悠远亚毫米亮星系中的原位核球构成▲ 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▲择要：当今宇宙中的年夜少数恒星都位于核球中，核球是螺旋星系跟椭圆星系的凑集，其构成还是一个未解之谜。久长以来，人们始终猜忌高红移的红外/亚毫米亮星系与核球构成有关。但是到现在为止，因为存眷核球恒星发射时重大的灰尘掩蔽，或囿于察看亚毫米波长时的方式跟无限信噪比，这种关系始终很难过到证实。研讨组证实了核球由悠远宇宙中高亮度的星暴星系中心内的恒星构成直接发生。这是由ALMA亚毫米名义亮度散布得出的。该散布与指数盘的亮度散布跟倾斜的高轴比散布有很年夜偏向。这些星系中的年夜少数都是完整三轴的，而不是扁平的圆盘：其三轴中最短轴跟最长轴的比率均匀为一半，而且跟着空间紧凑度的增添而增添。该观察成果失掉了模子的支撑，提醒了一个经由过程星暴原位构成核球的宇宙学相干道路，这可能由感化于非共面气体吸积流供应的星系彼此感化（跟兼并）优先触发。▲ 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PhysicsObservation of Hilbert space fragmentation and fractonic excitations in 2D二维希尔伯特空间碎片跟分形激起的观察▲ 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▲择要：离开均衡状况的伶仃量子体系的弛豫行动是多体物理学中最风趣的成绩之一。非均衡态的量子体系平日经由过程捣乱部分信息跟树立胶葛熵而弛豫到热均衡态。但是，哈密顿量中的能源学束缚可能招致这一基础范式的瓦解。由于基本希尔伯特空间决裂成静态解耦的子扇区，此中热化被激烈克制。研讨组经由过程试验观察了二维倾斜玻色-哈伯德模子中的希尔伯特空间碎片。应用量子气体显微镜，他们计划了种种百般的初始状况，并发明了希尔伯特空间碎片的丰盛表示情势，包含身形、界面跟缺点，即二维、一维跟零维物体。详细而言，存在雷同粒子数跟能量的平均初始态在弛豫能源学上有明显差别。在团体、非热化的棋盘式状况上拔出受控缺点，研讨组察看到高度各向异性的亚维能源学，这是其分形性子的直接标记。局域态跟热化态之间的界面顺次表示出根据其取向的能源学。该研讨成果标记着超出一维的希尔伯特空间碎片的观察，以及随同的分形直接察看，为深刻研讨束缚体系中的微不雅输运景象奠基了基本。▲ 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.资料迷信Materials ScienceMineralized 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▲ 择要：自体骨（AB）是骨移植手术的金尺度，只管其可用性无限且须要额定的手术部位。传统上，用于骨修复的竞争性生物资料重要聚焦模拟骨的矿物资方面，生物活性陶瓷的普遍临床利用证实了这一点。但是，AB也表示出可能会重大影响骨再生的分层无机构造。研讨组在小鼠跟绵羊骨缺损模子中应用了一系列无细胞仿生胶原基资料，证实了分层混杂微不雅构造（特殊是胶原的歪曲胶合板形式及其与结晶不良的生物磷灰石的联合）有利于骨再生。该研讨标明，构造上最仿生的资料存在安慰骨成长的潜力，凸起了物理化学特征在支撑骨构成中的要害感化，并为存在竞争力的骨移植资料供给了辽阔的远景。▲ Abstract：Autologous bone (AB) is the gold standard for bone-replacement surgeries, despite its limited availability and the need for an extra surgical site. Traditionally, competitive biomaterials for bone repair have focused on mimicking the mineral aspect of bone, as evidenced by the widespread clinical use of bioactive ceramics. However, AB also exhibits hierarchical organic structures that might substantially affect bone regeneration. Here, using a range of cell-free biomimetic-collagen-based materials in murine and ovine bone-defect models, we demonstrate that a hierarchical hybrid microstructure—specifically, the twisted plywood pattern of collagen and its association with poorly crystallized bioapatite—favourably influences bone regeneration. Our study shows that the most structurally biomimetic material has the potential to stimulate bone growth, highlighting the pivotal role of physicochemical properties in supporting bone formation and offering promising prospects as a competitive bone-graft material.信息迷信Information ScienceCombining quantum processors with real-time classical communication将量子处置器与及时经典通讯相联合▲ 作者：Almudena Carrera Vazquez, Caroline Tornow, Diego Ristè, Stefan Woerner, Maika Takita & Daniel J. Egger▲ 链接：https://www.nature.com/articles/s41586-024-08178-2▲ 择要：量子盘算机依据量子力学定律来处置信息。现在的量子硬件存在噪声，只能在短时光内存储信息，且仅限于多少个量子比特（即量子位），平日以立体衔接陈列。但是，量子盘算的很多利用须要比单个量子处置单位（QPU）更多量子位的硬件所供给立体晶格更多的连通性。学界盼望经由过程应用经典通讯衔接QPU来处理这些限度，这尚未失掉试验证实。研讨组经由过程试验实现了偏差下降的静态电路跟电路切割，应用多达142个量子位、逾越两个各有127个量子位且经由过程经典链路及时衔接的QPU，来创立须要周期性衔接的量子态。在静态电路中，量子门可在运转时光（量子位相关时光的一小局部）内，经由过程旁边电路丈量的成果停止经典把持。研讨组的及时经典链路使其可能依据另一个QPU的丈量成果在此中一个QPU上利用量子门。别的，偏差下降的把持流加强了量子比特的连通性跟硬件的指令集，从而晋升了量子盘算机的通用性。该任务标明，人们可将多个量子处置器作为一个团体，经由过程及时经典链路实现偏差下降的静态电路。▲ 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ChemistryCoupling of unactivated alkyl electrophiles using frustrated ion pairs用碰壁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▲ 择要：穿插亲电偶联反映已开展成为疾速组装主要无机分子的重要战略。两种易于取得的亲电试剂偶联构成新的C-C键，与须要事后构成活性无机金属物资的传统穿插偶联战略比拟存在要害上风。但是，构成多少乎全部无机化合物中心的C(sp3)–C(sp3)键对以后战略而言仍颇具挑衅，亟需计划翻新战略。研讨组报道了一个奇特且无过渡金属的平台来构成这种键，而无需激活或稳固偶联工具上的基团。该反映由碰壁离子对中不平常的单电子转移来实现，可偶联含有官能团的片断，这在相干的过渡金属催化进程中颇具挑衅性。别的，这种新机器流形可进一步利用于其余反映的计划，展现了这种反映的普遍潜力。研讨组估计该成果将为进一步摸索这种反映形式供给一个框架，以处理无机分解中的挑衅性困难。▲ Abstract：Cross-electrophile coupling reactions have evolved into a major strategy for rapidly assembling important organic molecules. Two readily accessible electrophiles are coupled to form new C–C bonds, providing a key advantage over traditional cross-coupling strategies that require the preformation of reactive organometallic species. Yet, the formation of C(sp3)–C(sp3) bonds that form the core of nearly all organic compounds remains highly challenging with current approaches, calling for the design of innovative new strategies. Here we report a distinct, transition-metal-free platform to form such bonds without the need for activating or stabilizing groups on the coupling partners. The reaction is enabled by an unusual single-electron transfer in a frustrated ion pair, and it can couple fragments containing functional groups that would be challenging in related transition-metal-catalysed processes. Moreover, we could further leverage this new mechanistic manifold in the design of other reactions, showing the broad potential of this type of reactivity. We anticipate that our results will provide a framework for further exploration of this reactivity pattern to tackle challenging problems in organic synthesis.地球迷信Earth ScienceIsoprene nitrates drive new particle formation in Amazon’s upper troposphere异戊二烯硝酸盐驱动亚马逊上对流层构成新粒子▲ 作者：Joachim Curtius, Martin Heinritzi, Lisa J. Beck, Mira L. P?hlker, Nidhi Tripathi, Bianca E. Krumm, et al.▲ 链接：https://www.nature.com/articles/s41586-024-08192-4▲ 择要：寒带上对流层的新粒子构成（NPF）是寰球年夜气气溶胶的主要起源。家喻户晓，NPF产生在亚马逊盆地，但成核机制跟化学前体尚未断定。研讨组供给了片面的原位飞机丈量成果，标明异戊二烯的极低挥发性氧化产品（特殊是某些无机硝酸盐）驱动了亚马逊上对流层的NPF。无机硝酸盐源于在雷电发生的氮氧化物存鄙人，丛林排放物中异戊二烯由OH激发的氧化。在日出后约2小时，夜间深对流的外流中开端成核暴发，发生超越每破方厘米50000个颗粒的高气溶胶浓度。研讨组报道了先驱气体跟粒子的特点日周期的丈量成果。观察成果标明，生物成因的异戊二烯、随同闪电的寒带深对流、氧化光化学跟低情况温度之间的彼此感化奇特地增进了NPF。这些粒子跟着时光的推移而增加，经由远间隔传输，并经由过程沉降降落到下对流层，在那边可作为云凝固核（CCN），影响地球的水文轮回、辐射进出跟气象。▲ 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. 申明：新浪网独家稿件，未经受权制止转载。 -->小编：[db:摘要]
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