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发布日期：2024-10-05 作者：华体会
Nature, 15 August 2024, Volume 632, Issue 8025
《天然》2024年8月15日，第632卷，8025期
天文学Astronomy
Bound star clusters observed in a lensed galaxy 460?Myr after the Big Bang
年夜爆炸后4.6亿年透镜星系中不雅测到的引力束厄局促星团
▲ 作者：Angela Adamo, Larry D. Bradley, Eros Vanzella, Adéla?de Claeyssens, Brian Welch, Jose M. Diego, et al.
▲链接：
https://www.nature.com/articles/s41586-024-07703-7
▲摘要：
“宇宙宝石弧”星系是在红移z≈10.2处不雅测到的最敞亮和高度放年夜的星系之一。但是，其素质上是一个紫外线微弱的星系，处在那些现被认为驱动宇宙再电离的星系规模内。迄今为止，在近似红移的星系平分辨出的最小特点在几百到几十秒差距（pc）之间。
研究组报导了JWST对“宇宙宝石弧”的不雅测。该星系的光被分化成五个星团，位在一个小在70 pc的区域内。这些星团表示出最小的尘埃衰减和低金属品貌，春秋小在50 Myr，本征质量约为106M⊙。其透镜校订尺寸约为1 pc，致使恒星概况密度接近105M⊙pc?2，比近域宇宙中典型的年青星团高三个数目级。
虽然透镜模子存在固有不肯定性，但其与引力束厄局促的恒星系统（即原始球状星团）一致。研究组得出结论，星团的构成和反馈可能有助在塑造再电离期间星系的特征。
▲ Abstract：
The Cosmic Gems arc is among the brightest and highly magnified galaxies observed at redshift z?≈?10.2. However, it is an intrinsically ultraviolet faint galaxy, in the range of those now thought to drive the reionization of the Universe. Hitherto the smallest features resolved in a galaxy at a comparable redshift are between a few hundreds and a few tens of parsec华体会体育apps (pc). Here we report JWST observations of the Cosmic Gems. The light of the galaxy is resolved into five star clusters located in a region smaller than 70?pc. They exhibit minimal dust attenuation and low metallicity, ages younger than 50?Myr and intrinsic masses of about 106M⊙. Their lensing-corrected sizes are approximately 1?pc, resulting in stellar surface densities near 105M⊙pc?2, three orders of magnitude higher than typical young star clusters in the local Universe. Despite the uncertainties inherent to the lensing model, they are consistent with being gravitationally bound stellar systems, that is, proto-globular clusters. We conclude that star cluster formation and feedback likely contributed to shaping the properties of galaxies during the epoch of reionization.
材料科学Materials Science
Multi-heterojunctioned plastics with high thermoelectric figure of merit
具有高热电品质因数的多异质结塑料
▲ 作者：Dongyang Wang, Jiamin Ding, Yingqiao Ma, Chunlin Xu, Zhiyi Li, Xiao Zhang, et al.
▲链接：
https://www.nature.com/articles/s41586-024-07724-2
▲摘要：
共轭聚合物有望成为矫捷、低本钱的热电材料，操纵废热为物联网供电。但是，迄今为止，其有价值的利用一向遭到无量纲品质因数（ZT）较低的阻碍。
研究组报导了高ZT热电塑料，经由过程建立具有周期性双异质结特点的聚合物多异质结来实现，此中每一个周期由两种具有低在10纳米层状异质结布局和互穿体异质结界面的聚合物构成。这类几何布局显著加强了界面类声子散射，同时连结了有用的电荷输运。
研究组不雅察到，与单个聚合物比拟，该塑料的导热系数显著下降了60%以上，功率因数提高，致使ZT在368 K时高达1.28。这类聚合物的热电机能超出了商用热电材料和现有的柔性热电候选材料。
主要的是，研究组证实了聚合物多异质结布局与溶液涂层手艺的兼容性，以知足年夜面积塑料热电材料的需求，可助力聚合物多异质结向本钱效益高的可穿着热电手艺的成长。
▲ Abstract：
Conjugated polymers promise inherently flexible and low-cost thermoelectrics for powering the Internet of Things from waste heat. Their valuable applications, however, have been hitherto hindered by the low dimensionless figure of merit (ZT). Here we report high-ZT thermoelectric plastics, which were achieved by creating a polymeric multi-heterojunction with periodic dual-heterojunction features, where each period is composed of two polymers with a sub-ten-nanometre layered heterojunction structure and an interpenetrating bulk-heterojunction interface. This geometry produces significantly enhanced interfacial phonon-like scattering while maintaining efficient charge transport. We observed a significant suppression of thermal conductivity by over 60?per cent and an enhanced power factor when compared with individual polymers, resulting in a ZT of up to 1.28 at 368?kelvin. This polymeric thermoelectric performance surpasses that of commercial thermoelectric materials and existing flexible thermoelectric candidates. Importantly, we demonstrated the compatibility of the polymeric multi-heterojunction structure with solution coating techniques for satisfying the demand for large-area plastic thermoelectrics, which paves the way for polymeric multi-heterojunctions towards cost-effective wearable thermoelectric technologies.
Buried interface molecular hybrid for inverted perovskite solar cells
颠倒钙钛矿太阳能电池的埋底界面份子杂化
▲ 作者：Sanwan Liu, Jingbai Li, Wenshan Xiao, Rui Chen, Zhenxing Sun, Yong Zhang, et al.
▲链接：
https://www.nature.com/articles/s41586-024-07723-3
▲摘要：
与传统器件布局比拟，颠倒布局的钙钛矿太阳能电池具有更好的功率转换效力和运行不变性，为这一新兴光伏手艺的贸易化供给了要害路径。具体而言，因为改良的自组装份子和钝化策略的成长，颠倒钙钛矿太阳能电池的功率转换效力跨越了25%。但是，自组装份子的润湿性差和易堆积会致使界面损掉，阻碍了功率转换效力和不变性的进一步提高。
研究组报导了颠倒钙钛矿太阳能电池中埋底界面处的份子杂化，可将风行的自组装份子[4-（3,6-二甲基-9H-咔唑-9-基）丁基]膦酸（Me-4PACz）与多重芳羧酸4,4‘,4”-三甲酸三苯胺（NA）共组装以改良异质结界面。Me-4PACz与NA的份子杂化可显著改良其界面特征。由此制备的颠倒钙钛矿太阳能电池到达了26.54%的记实认证稳态效力。
相当主要的是，该策略可与年夜范围制备无缝跟尾，实现了高达22.74%的颠倒微型模块最高认证功率转换效力之一（孔径面积为11.1 cm2）。该装备在情况空气中1太阳光强运行跨越2400小时后，仍连结96.1%的初始功率转换效力。
▲ Abstract：
Perovskite solar cells with an inverted architecture provide a key pathway for commercializing this emerging photovoltaic technology because of the better power conversion efficiency and operational stability compared with the normal device structure. Specifically, power conversion efficiencies of the inverted perovskite solar cells have exceeded 25% owing to the development of improved self-assembled molecules and passivation strategies. However, poor wettability and agglomeration of self-assembled molecules cause interfacial losses, impeding further improvement in the power conversion efficiency and stability. Here we report a molecular hybrid at the buried interface in inverted perovskite solar cells that co-assembled the popular self-assembled molecule [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz) with the multiple aromatic carboxylic acid 4,4′,4″-nitrilotribenzoic acid (NA) to improve the heterojunction interface. The molecular hybrid of Me-4PACz with NA could substantially improve the interfacial characteristics. The resulting inverted perovskite solar cells demonstrated a record certified steady-state efficiency of 26.54%. Crucially, this strategy aligns seamlessly with large-scale manufacturing, achieving one of the highest certified power conversion efficiencies for inverted mini-modules at 22.74% (aperture area 11.1?cm2). Our device also maintained 96.1% of its initial power conversion efficiency after more than 2,400?h of 1-sun operation in ambient air.
化学Chemistry
A general strategy for the synthesis of taxane diterpenes
紫杉烷二萜合成的通用策略
▲ 作者：Lu Pan, Fabian Schneider, Moritz Ottenbruch, Rainer Wiechert, Tatjana List, Philipp Schoch, et al.
▲链接：
https://www.nature.com/articles/s41586-024-07675-8
▲摘要：
任何有机份子的碳框架都是其三维布局的根本，在决议其物理和生物特征方面起着要害感化。是以，紫杉烷二萜是最知名的自然产品家族之一，这首要归功在其最凸起的化合物紫杉醇的成功，紫杉醇是一种有用的抗癌医治药物，已有25年以上的汗青。
与传统紫杉烷比拟，环紫杉烷（也称为紫杉烷复合物）的生物活性仍未获得充实研究。这两组紫杉烷类的碳框架存在显著差别，是以其各自怪异的合成方式也分歧。
研究组报导了一种基在复杂份子框架彼此转化的多功能合成策略，供给了生成更普遍的紫杉烷二萜家族产品的通用处径。
他们制备了一系列经典框架和环紫杉烷框架，此中包罗由单一高级中心体全合成的紫杉宁K（2）、canataxapropellane（5）和二螺桨烷C。合成方式居心避开仿生策略，而凸起立体电子节制以调和多环框架彼此转换的能力。
▲ Abstract：
The carbon skeleton of any organic molecule serves as the foundation for its three-dimensional structure, playing a pivotal role in determining its physical and biological properties. As such, taxane diterpenes are one of the most well-known natural product families, primarily owing to the success of their most prominent compound, paclitaxel, an effective anticancer therapeutic for more than 25?years. In contrast to classical taxanes, the bioactivity of cyclotaxanes (also referred to as complex taxanes) remains significantly underexplored. The carbon skeletons of these two groups of taxanes differ significantly, and so would typically their own distinct synthetic approaches. Here we report a versatile synthetic strategy based on the interconversion of complex molecular frameworks, providing general access to the wider taxane diterpene family. A range of classical and cyclotaxane frameworks was prepared including, among others, the total syntheses of taxinine K (2), canataxapropellane (5) and dipropellane C from a single advanced intermediate. The synthetic approach deliberately eschews biomimicry, emphasizing instead the power of stereoelectronic control in orchestrating the interconversion of polycyclic frameworks.
地球科学Earth Science
Global net climate effects of anthropogenic reactive nitrogen
报酬活性氮的全球净天气效应
▲ 作者：Cheng Gong, Hanqin Tian, Hong Liao, Naiqing Pan, Shufen Pan, Akihiko Ito, et al.
▲链接：
https://www.nature.com/articles/s41586-024-07714-4
▲摘要：
自前工业时期以来，报酬勾当年夜年夜增添了地球系统中活性氮（Nr）的负荷，致使了普遍的富营养化和空气污染。增添的Nr还可经由过程对年夜气和陆地进程的各类感化来影响全球天气，但积累的净天气效应尚不清晰。
研究组注解，与1850年比拟，2019年报酬Nr酿成的净负直接辐射逼迫为-0.34 [-0.20，-0.50] W m-2。这类净冷却效应是气溶胶负荷增添、甲烷寿命缩短和与报酬Nr增添相干的陆地碳固存增添的成果，而年夜气一氧化二氮和臭氧加强的增温效应没法抵消这些影响。
利用三种代表脾气景的将来猜测注解，这类冷却效应可能首要因气溶胶负荷削减和甲烷寿命耽误而削弱，特别是N2O引发的变暖可能会在所有情形下继续增添。该研究成果注解，为了实现情况庇护方针，将来在削减报酬Nr的同时，仍需加鼎力度削减报酬温室气体排放，以实现《巴黎协议》减缓天气转变的方针。
▲ Abstract：
Anthropogenic activities have substantially enhanced the loadings of reactive nitrogen (Nr) in the Earth system since pre-industrial times, contributing to widespread eutrophication and air pollution. Increased Nr can also influence global climate through a variety of effects on atmospheric and land processes but the cumulative net climate effect is yet to be unravelled. Here we show that anthropogenic Nr causes a net negative direct radiative forcing of ?0.34?[?0.20, ?0.50]?W?m-2 in the year 2019 relative to the year 1850. This net cooling effect is the result of increased aerosol loading, reduced methane lifetime and increased terrestrial carbon sequestration associated with increases in anthropogenic Nr, which are not offset by the warming effects of enhanced atmospheric nitrous oxide and ozone. Future predictions using three representative scenarios show that this cooling effect may be weakened primarily as a result of reduced aerosol loading and increased lifetime of methane, whereas in particular N2O-induced warming will probably continue to increase under all scenarios. Our results indicate that future reductions in anthropogenic Nr to achieve environmental protection goals need to be accompanied by enhanced efforts to reduce anthropogenic greenhouse gas emissions to achieve climate change mitigation in line with the Paris Agreement.
Deep crustal assimilation during the 2021 Fagradalsfjall Fires, Iceland
2021年冰岛Fagradalsfjall年夜火时代的地壳深部同化
▲ 作者：James M. D. Day, Savannah Kelly, Valentin R. Troll, William M. Moreland, Geoffrey W. Cook Thor Thordarson
▲链接：
https://www.nature.com/articles/s41586-024-07750-0
▲摘要：
活跃的玄武岩喷发有望实现地球化学和地球物理性质的时候序列阐发，为地幔成份和喷发进程供给了束缚前提。从2021年最先，冰岛雷克雅内斯半岛延续的Fagradalsfjall和Sundhnúkur年夜火使该方式成为可能。这一火山期间最早的熔岩被注释为仅反应了从浅层到深层地幔源进程的转变。
研究组利用锇（Os）同位素注解，2021年Fagradalsfjall熔岩既部门结晶，又遭到强烈的地壳混染，便可能遭到雷克雅内斯半岛下的洋中脊辉长岩和更古老玄武岩的污染。最早喷发产品（187Os/188Os≤0.188，铂（Pt）/铱（Ir）≤76）对冰岛熔岩或全球海洋玄武岩而言高度异常，在全部2021年喷发时代，Os同位素比值依然升高，注解混染物延续存在，但被稀释了。
2022年熔岩没有混染迹象（187Os/188Os=0.131，Pt/Ir=30），是典型的冰岛玄武岩（0.132±0.007）。2021年，Fagradalsfjall年夜火爆发，触及最早熔岩的喷发前阻滞、分手结晶和地壳同化。2022年成立的岩浆通道系统使岩浆在没有地壳同化的环境下可以或许有用地向地表输送。
▲ Abstract：
Active basaltic eruptions enable time-series analysis of geochemical and geophysical properties, providing constraints on mantle composition and eruption processes. The continuing Fagradalsfjall and Sundhnúkur fires on Iceland’s Reykjanes Peninsula, beginning in 2021, enable such an approach. Earliest lavas of this volcanic episode have been interpreted to exclusively reflect a change from shallow to deeper mantle source processes. Here we show using osmium (Os) isotopes that the 2021 Fagradalsfjall lavas are both fractionally crystallized and strongly crustally contaminated, probably by mid-ocean-ridge gabbros and older basalts underlying the Reykjanes Peninsula. Earliest eruptive products (187Os/188Os≤?0.188, platinum (Pt)/iridium (Ir)?≤?76) are highly anomalous for Icelandic lavas or global oceanic basalts and Os isotope ratios remain elevated throughout the 2021 eruption, indicating a continued but diluted presence of contaminants. The 2022 lavas show no evidence for contamination (187Os/188Os=?0.131, Pt/Ir?=?30), being typical of Icelandic basalts (0.132?±?0.007). Initiation of the Fagradalsfjall Fires in 2021 involved pre-eruptive stalling, fractional crystallization and crustal assimilation of earliest lavas. An established magmatic conduit system in 2022 enabled efficient magma transit to the surface without crustal assimilation.
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