《天然》（20250213出书）一周论文导读

编译 | 未玖Nature,13 February 2025, Volume 638, Issue 8050《天然》2025年2月13日，第638卷，8050期地理学AstronomyDirectly imaging the cooling flow in the Phoenix cluster直接成像凤凰星团中的冷却流▲ 作者：Michael Reefe, Michael McDonald, Marios Chatzikos, Jerome Seebeck, Richard Mushotzky, Sylvain Veilleux, et al.▲ 链接：https://www.nature.com/articles/s41586-024-08369-x ▲ 择要：在很多星系团的核心，灼热（大概107开尔文）星系团内介质可变得充足致密，甚至于其本应在短时光内冷却。但是，在年夜品质核心星系中丈量到的恒星构成率很低，且冷却气体中不软X射线，这标明年夜少数气体从未冷却过。这就是所谓的冷却流成绩。最新观察标明，黑洞喷流使绝年夜少数气体坚持在低温状况。任何星系团中的全部气相中，冷却流尚未实现全绘制。研讨组展现了应用詹姆斯韦伯太空千里镜对凤凰星团的观察，绘制了[Ne vi] λ 7.652-μm发射线，使人们可能在年夜标准上探测105.5? K的气体。这些数据表现了扩大的[Ne vi]发射，与星系团内介质的冷却峰、最冷的气相跟活泼恒星构成的地位同空间存在。综上所述，这象征着近来产生了一次疾速冷却，招致了冷却速率长久飙升，研讨组估量为每年5000~23000个太阳品质。这些数据供给了星系团中心温度在105 K到106 K之间的年夜范围气体散布图景，并夸大了黑洞反应在调理冷却跟增进冷却方面的要害感化。▲ Abstract：In the centres of many galaxy clusters, the hot (approximately 107 kelvin) intracluster medium can become dense enough that it should cool on short timescales. However, the low measured star formation rates in massive central galaxies and the absence of soft X-ray lines from the cooling gas suggest that most of this gas never cools. This is known as the cooling flow problem. The latest observations suggest that black hole jets are maintaining the vast majority of gas at high temperatures. A cooling flow has yet to be fully mapped through all the gas phases in any galaxy cluster. Here we present observations of the Phoenix cluster using the James Webb Space Telescope to map the [Ne vi] λ 7.652-μm emission line, enabling us to probe the gas at 105.5?kelvin on large scales. These data show extended [Ne vi] emission that is cospatial with the cooling peak in the intracluster medium, the coolest gas phases and the sites of active star formation. Taken together, these imply a recent episode of rapid cooling, causing a short-lived spike in the cooling rate, which we estimate to be 5,000–23,000 solar masses per year. These data provide a large-scale map of gas at temperatures between 105?kelvin and 106?kelvin in a cluster core, and highlight the critical role that black hole feedback has in not only regulating cooling but also promoting it.The bulk motion of gas in the core of the Centaurus galaxy cluster半人马座星系团中心气体的团体活动▲ 作者：XRISM collaboration▲ 链接：https://www.nature.com/articles/s41586-024-08561-z ▲ 择要：星系团包括大批被称为星系团内介质（ICM）的热电离气体。在分散星系团中心中，ICM的辐射冷却时光短于星系团年纪。但是，与冷却相干的线发射缺掉标明加热机制对消了冷却，来自运动星系核（AGNs）的反应是最有可能的起源。湍流跟团体活动，如星系团势阱中中心气体的振荡（打击）活动，也被以为是中心外部热量散布的机制。研讨组用X射线成像跟光谱义务卫星对半人马座星系团停止X射线光谱观察。成果发明，热气体沿着绝对于核心星系的视线活动，在间隔核心约30 kpc的范畴内，速率从130 km s?1到310 km s?1。这标明团体活动与中心气体晃悠分歧。固然团体活动可避免核心冷却气体的适度积累，但亦可疏散AGN注入的热量，并从四周的ICM中引入热能。中心气体的速率色散仅为≤120 km s?1，乃至在AGN的10 kpc范畴内亦是如斯。这标明AGN对四周ICM活动的影响在星系团中是无限的。▲ Abstract：Galaxy clusters contain vast amounts of hot ionized gas known as the intracluster medium (ICM). In relaxed cluster cores, the radiative cooling time of the ICM is shorter than the age of the cluster. However, the absence of line emission associated with cooling suggests heating mechanisms that offset the cooling, with feedback from active galactic nuclei (AGNs) being the most likely source. Turbulence and bulk motions, such as the oscillating (‘sloshing’) motion of the core gas in the cluster potential well, have also been proposed as mechanisms for heat distribution from the outside of the core. Here we present X-ray spectroscopic observations of the Centaurus galaxy cluster with the X-Ray Imaging and Spectroscopy Mission satellite. We find that the hot gas flows along the line of sight relative to the central galaxy, with velocities from 130?km?s?1 to 310?km?s?1 within about 30?kpc of the centre. This indicates bulk flow consistent with core gas sloshing. Although the bulk flow may prevent excessive accumulation of cooled gas at the centre, it could distribute the heat injected by the AGN and bring in thermal energy from the surrounding ICM. The velocity dispersion of the gas is found to be only ?120?km?s?1 in the core, even within about 10?kpc of the AGN. This suggests that the influence of the AGN on the surrounding ICM motion is limited in the cluster.资料迷信Materials ScienceMetal-halide porous framework superlattices金属卤化物多孔骨架超晶格▲ 作者：Wenqiang Zhang, Hong Jiang, Yikuan Liu, Yue Hu, Athulya Surendran Palakkal, Yujie Zhou, et al.▲ 链接：https://www.nature.com/articles/s41586-024-08447-0 ▲ 择要：经由过程构建存在化学身分空间调制的超晶格构造，可创立存在可定制周期性电势景不雅跟可调谐电子跟光学特征的天然资料。存在一维可计划电位调制的传统半导体超晶格实现了高电子迁徙率晶体管跟量子级联激光器。近来，经由过程多标准构建单位的自组装或领导组装，人们构建了一组多样化的超晶格，包含零维纳米簇跟纳米颗粒、一维纳米棒跟纳米线、二维纳米层跟纳米片，以及混杂二维分子组装体。这些自组装超晶格存在二维或三维的周期性构造调制，但因为构成单位之间界面处弗成防止的构造无序，平日缺少原子精度。研讨组讲演了由零维、一维跟二维构建单位的周期性陈列构成的多维单晶超晶格的一锅分解法。应用锆（IV）金属无机骨架作为主模板，经由过程配位帮助组装战略实现金属卤化物亚晶格的定向成核跟准确成长，他们分解了一系列单晶多孔超晶格。单晶X射线晶体学跟高辨别率透射电子显微镜清楚地辨别出存在断定性原子坐标的高阶超晶格构造。用选定的胺分子进一步处置可发生存在高度可调光致发光跟手性光学性子的钙钛矿样超晶格。该研讨创立了一个高阶单晶多孔超晶格平台，为定制传统晶体固体无奈实现的电子、光学跟量子特征供给了机会。▲ Abstract：The construction of superlattices with a spatial modulation of chemical compositions allows for the creation of artificial materials with tailorable periodic potential landscapes and tunable electronic and optical properties. Conventional semiconductor superlattices with designable potential modulation in one dimension has enabled high-electron-mobility transistors and quantum-cascade lasers. More recently, a diverse set of superlattices has been constructed through self-assembly or guided assembly of multiscale building units, including zero-dimensional nanoclusters and nanoparticles, one-dimensional nanorods and nanowires, two-dimensional nanolayers and nanosheets, and hybrid two-dimensional molecular assemblies. These self-assembled superlattices feature periodic structural modulation in two or three dimensions, but often lack atomic precision owing to the inevitable structural disorder at the interfaces between the constituent units. Here we report a one-pot synthesis of multi-dimensional single-crystalline superlattices consisting of periodic arrangement of zero-, one- and two-dimensional building units. By exploiting zirconium (IV) metal–organic frameworks as host templates for directed nucleation and precise growth of metal-halide sublattices through a coordination-assisted assembly strategy, we synthesize a family of single-crystalline porous superlattices. Single-crystal X-ray crystallography and high-resolution transmission electron microscopy clearly resolve the high-order superlattice structure with deterministic atomic coordinates. Further treatment with selected amine molecules produces perovskite-like superlattices with highly tunable photoluminescence and chiroptical properties. Our study creates a platform of high-order single-crystalline porous superlattices, opening opportunities to tailor the electronic, optical and quantum properties beyond the reach of conventional crystalline solids.化学ChemistryTwo-dimensional polyaniline crystal with metallic out-of-plane conductivity存在面外金属性电导率的二维聚苯胺晶体▲ 作者：Tao Zhang, Shu Chen, Petko St. Petkov, Peng Zhang, Haoyuan Qi, Nguyen Ngan Nguyen, et al.▲ 链接：https://www.nature.com/articles/s41586-024-08387-9 ▲ 择要：线性导电聚合物表示出由沿聚合物链挪动的挪动载流子施加的弹道传输，但因为缺少分子间有序跟电子耦合，在扩大维度（即聚合物链或层之间）上的电导率依然很弱。研讨组报道了一种多层重叠的二维聚苯胺（2DPANI）晶体，其存在高导电性的面外金属性电荷输运。该资料包含层间距为3.59 ?的柱状π阵列跟由聚苯胺链交错构成的周期性菱面体晶格。电子自旋共振谱提醒了2DPANI晶格中明显的电子离域。第一性道理盘算标明，Cl -桥接层重叠增进了2DPANI的面内二维共轭跟层间强电子耦合。为了评价部分光学电导率，研讨组应用太赫兹跟红外纳米光谱技巧来提醒德鲁德型电导率，其红外等离子体频率及外推的部分直流电导率约为200 S cm?1 。导电扫描探针显微镜表现，其面外电导率异样高，约为15 S cm?1 。经由过程垂直跟横向微器件停止的电荷传输丈量表现，面外电导率（约7 S cm?1 ）跟面内电导率（约16 S cm?1 ）相称高。垂直微器件的电导率随温度的下降而加强，表示出奇特的面外金属性输运转为。经由过程应用这种多层重叠的二维导电聚合物计划，研讨组猜测在面内彼此感化之外实现强电子耦合，无望实现三维金属性电导率。▲ Abstract：Linear conducting polymers show ballistic transport, imposed by mobile carriers moving along the polymer chains, whereas conductance in the extended dimension, that is, between polymer strands or layers, remains weak due to the lack of intermolecular ordering and electronic coupling. Here we report a multilayer-stacked two-dimensional polyaniline (2DPANI) crystal, which shows metallic out-of-plane charge transport with high electrical conductivity. The material comprises columnar π arrays with an interlayer distance of 3.59?? and periodic rhombohedral lattices formed by interwoven polyaniline chains. Electron spin resonance spectroscopy reveals significant electron delocalization in the 2DPANI lattices. First-principles calculations indicate the in-plane 2D conjugation and strong interlayer electronic coupling in 2DPANI facilitated by the Cl-bridged layer stacking. To assess the local optical conductivity, we used terahertz and infrared nanospectroscopy to unravel a Drude-type conductivity with an infrared plasma frequency and an extrapolated local d.c. conductivity of around 200?S?cm?1. Conductive scanning probe microscopy showed an unusually high out-of-plane conductivity of roughly 15?S?cm?1. Transport measurements through vertical and lateral micro-devices revealed comparable high out-of-plane (roughly 7?S?cm?1) and in-plane conductivity (roughly 16?S?cm?1). The vertical micro-devices further showed increasing conductivity with decreasing temperature, demonstrating unique out-of-plane metallic transport behaviour. By using this multilayer-stacked 2D conducting polymer design, we predict the achievement of strong electronic coupling beyond in-plane interactions, potentially reaching three-dimensional metallic conductivity.H-bonded organic frameworks as ultrasound-programmable delivery platform氢键无机框架助力超声可编程传输平台▲ 作者：Wenliang Wang, Yanshu Shi, Wenrui Chai, Kai Wing Kevin Tang, Ilya Pyatnitskiy, Yi Xie, et al.▲ 链接：https://www.nature.com/articles/s41586-024-08401-0 ▲ 择要：应用非侵入性超声准确把持深层构造内的机器化学激活，对增进人们对基本生物医学迷信的懂得跟彻底转变疾病医治战略存在深远意思。但是，一种存在明白界说超声激活的实践领导机器呼应资料体系尚待摸索。研讨组提出了应用多孔氢键无机框架（HOFs）作为聚焦超声（FUS）可编程触发药物激活东西包的观点，经由过程按需裂解超分子彼此感化来把持脑深部的特定细胞变乱。他们树立了机器化学断裂跟超声力学的可视化实践模子，为公道计划机器呼应资料以实现可编程把持供给了有代价的领导。为了证实这种方式的适用性，研讨组将计划药物氯氮平N-氧化物（CNO）封装到用于FUS门控开释的最佳HOF纳米晶体中，以激活小鼠跟年夜鼠腹侧被盖区（VTA）的工程G卵白偶联受体，即便在9毫米深度的构造内也能实现靶神经回路调理，埋伏期仅为数秒。这项任务证实了超声准确把持分子彼此感化的才能，并开辟了超声波可编程的HOF，以非侵入性跟时空性地把持细胞变乱，无望实现准确分子医治。▲ Abstract：The precise control of mechanochemical activation within deep tissues using non-invasive ultrasound holds profound implications for advancing our understanding of fundamental biomedical sciences and revolutionizing disease treatments. However, a theory-guided mechanoresponsive materials system with well-defined ultrasound activation has yet to be explored. Here we present the concept of using porous hydrogen-bonded organic frameworks (HOFs) as toolkits for focused ultrasound (FUS) programmably triggered drug activation to control specific cellular events in the deep brain, through on-demand scission of the supramolecular interactions. A theoretical model is developed to potentially visualize the mechanochemical scission and ultrasound mechanics, providing valuable guidelines for the rational design of mechanoresponsive materials to achieve programmable control. To demonstrate the practicality of this approach, we encapsulate the designer drug clozapine N-oxide (CNO) into the optimal HOF nanocrystals for FUS-gated release to activate engineered G-protein-coupled receptors in the ventral tegmental area (VTA) of mice and rats and hence achieve targeted neural circuit modulation even at depth 9?mm with a latency of seconds. This work demonstrates the capability of ultrasound to precisely control molecular interactions and develops ultrasound-programmable HOFs to non-invasively and spatiotemporally control cellular events, thereby facilitating the establishment of precise molecular therapeutic possibilities.社会学SociologyRegional and institutional trends in assessment for academic promotion学术提升评价的地区跟机构趋向▲ 作者：B. H. Lim, C. D’Ippoliti, M. Dominik, A. C. Hernández-Mondragón, K. Vermeir, K. K. Chong, et al.▲ 链接：https://www.nature.com/articles/s41586-024-08422-9 ▲ 择要：研讨绩效评价被普遍以为是保持最高品质尺度的主要东西，人们以为抉择跟竞争会推进提高。学术机构在面对外部研讨评价压力的同时，亟需在应聘跟提升方面做出要害决议。研讨组基于190个学术机构的314项政策跟58个当局机构的218项政策（涵盖北半球32个国度跟南半球89个国度），对学术职业开展的研讨评价停止了瞻望，特殊存眷提升为正教学的政策。他们考察了种种提升尺度被说起的频率，并停止了统计剖析，以揣摸种种政策的个性跟差别。只管定量评价方式仍很风行，但与更受地舆限度的研讨成果分歧，其并非实用全部情形。研讨组发明北半球跟南半球之间存在差别，机构跟国度政策之间亦存在差别，但学科之间的差别较小。中高收入国度对文献计量指标的偏好更为显明。只管研讨组发明了一些差别，但很多提升政策都基于对已成为标准的特定职业途径停止假设，而非拥抱多样性。反过去，这限度了研讨职员的机遇。这些成果挑衅了以后实际，并对研讨职员、研讨治理职员跟国度当局存在策略意思。▲ Abstract：The assessment of research performance is widely seen as a vital tool in upholding the highest standards of quality, with selection and competition believed to drive progress. Academic institutions need to take critical decisions on hiring and promotion, while facing external pressure by also being subject to research assessment. Here we present an outlook on research assessment for career progression with specific focus on promotion to full professorship, based on 314 policies from 190 academic institutions and 218 policies from 58 government agencies, covering 32 countries in the Global North and 89 countries in the Global South. We investigated how frequently various promotion criteria are mentioned and carried out a statistical analysis to infer commonalities and differences across policies. Although quantitative methods of assessment remain popular, in agreement with what is found in more geographically restricted studies, they are not omnipresent. We find differences between the Global North and the Global South as well as between institutional and national policies, but less so between disciplines. A preference for bibliometric indicators is more marked in upper-middle-income countries. Although we see some variation, many promotion policies are based on the assumption of specific career paths that become normative rather than embracing diversity. In turn, this restricts opportunities for researchers. These results challenge current practice and have strategic implications for researchers, research managers and national governments.