《自然》（20240815出版）一周论文导读

 

编译|未玖

Nature, 15 August 2024, Volume 632, Issue 8025

《自然》2024年8月15日，第632卷，8025期

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天文学Astronomy

Bound star clusters observed in a lensed galaxy 460?Myr after the Big Bang

大爆炸后4.6亿年透镜星系中观测到的引力束缚星团

▲ 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处观测到的最明亮和高度放大的星系之一。然而，其本质上是一个紫外线微弱的星系，处于那些现被认为驱动宇宙再电离的星系范围内。迄今为止，在类似红移的星系中分辨出的最小特征在几百到几十秒差距（pc）之间。

研究组报道了JWST对“宇宙宝石弧”的观测。该星系的光被分解成五个星团，位于一个小于70 pc的区域内。这些星团表现出最小的尘埃衰减和低金属丰度，年龄小于50 Myr，本征质量约为10⁶M⊙。其透镜校正尺寸约为1 pc，导致恒星表面密度接近10⁵M⊙pc^?2，比近域宇宙中典型的年轻星团高三个数量级。

尽管透镜模型存在固有不确定性，但其与引力束缚的恒星系统（即原始球状星团）一致。研究组得出结论，星团的形成和反馈可能有助于塑造再电离时期星系的特性。

▲ 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 parsecs (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灵活、低成本的热电材料，利用废热为物联网供电。然而，迄今为止，其有价值的应用一直受到无量纲品质因数（ZT）较低的阻碍。

研究组报道了高ZT热电塑料，通过创建具有周期性双异质结特征的聚合物多异质结来实现，其中每个周期由两种具有低于10纳米层状异质结结构和互穿体异质结界面的聚合物组成。这种几何结构显著增强了界面类声子散射，同时保持了有效的电荷输运。

研究组观察到，与单个聚合物相比，该塑料的导热系数显著降低了60%以上，功率因数提高，导致ZT在368 K时高达1.28。这种聚合物的热电性能超越了商用热电材料和现有的柔性热电候选材料。

重要的是，研究组证明了聚合物多异质结结构与溶液涂层技术的兼容性，以满足大面积塑料热电材料的需求，可助力聚合物多异质结向成本效益高的可穿戴热电技术的发展。

▲ 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

倒置钙钛矿太阳能电池的埋底界面分子杂化

▲ 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：

与传统器件结构相比，倒置结构的钙钛矿太阳能电池具有更好的功率转换效率和运行稳定性，为这一新兴光伏技术的商业化提供了关键路径。具体而言，由于改进的自组装分子和钝化策略的发展，倒置钙钛矿太阳能电池的功率转换效率超过了25%。然而，自组装分子的润湿性差和易聚集会导致界面损失，阻碍了功率转换效率和稳定性的进一步提高。

研究组报道了倒置钙钛矿太阳能电池中埋底界面处的分子杂化，可将流行的自组装分子[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）共组装以改善异质结界面。Me-4PACz与NA的分子杂化可显著改善其界面特性。由此制备的倒置钙钛矿太阳能电池达到了26.54%的记录认证稳态效率。

至关重要的是，该策略可与大规模制备无缝衔接，实现了高达22.74%的倒置微型模块最高认证功率转换效率之一（孔径面积为11.1 cm²）。该设备在环境空气中1太阳光强运行超过2400小时后，仍保持96.1%的初始功率转换效率。

▲ 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：

任何有机分子的碳框架都是其三维结构的基础，在决定其物理和生物特性方面起着关键作用。因此，紫杉烷二萜是最知名的天然产物家族之一，这主要归功于其最突出的化合物紫杉醇的成功，紫杉醇是一种有效的抗癌治疗药物，已有25年以上的历史。

与传统紫杉烷相比，环紫杉烷（也称为紫杉烷复合物）的生物活性仍未得到充分研究。这两组紫杉烷类的碳框架存在显著差异，因此其各自独特的合成方法也不同。

研究组报道了一种基于复杂分子框架相互转化的多功能合成策略，提供了生成更广泛的紫杉烷二萜家族产物的通用途径。

他们制备了一系列经典框架和环紫杉烷框架，其中包括由单一高级中间体全合成的紫杉宁K（2）、canataxapropellane（5）和二螺桨烷C。合成方法故意避开仿生策略，而突出立体电子控制以协调多环框架相互转换的能力。

▲ 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

人为活性氮的全球净气候效应

▲ 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：

自前工业时代以来，人为活动大大增加了地球系统中活性氮（Nr）的负荷，导致了广泛的富营养化和空气污染。增加的Nr还可通过对大气和陆地过程的各种作用来影响全球气候，但累积的净气候效应尚不清楚。

研究组表明，与1850年相比，2019年人为Nr造成的净负直接辐射强迫为-0.34 [-0.20，-0.50] W m^-2。这种净冷却效应是气溶胶负荷增加、甲烷寿命缩短以及与人为Nr增加相关的陆地碳固存增加的结果，而大气一氧化二氮和臭氧增强的增温效应无法抵消这些影响。

使用三种代表性情景的未来预测表明，这种冷却效应可能主要因气溶胶负荷减少和甲烷寿命延长而减弱，尤其是N₂O引起的变暖可能会在所有情景下继续增加。该研究结果表明，为了实现环境保护目标，未来在减少人为Nr的同时，仍需加大力度减少人为温室气体排放，以实现《巴黎协定》缓解气候变化的目标。

▲ 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大火期间的地壳深部同化

▲ 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间序列分析，为地幔成分和喷发过程提供了约束条件。从2021年开始，冰岛雷克雅内斯半岛持续的Fagradalsfjall和Sundhnúkur大火使该方法成为可能。这一火山时期最早的熔岩被解释为仅反映了从浅层到深层地幔源过程的变化。

研究组使用锇（Os）同位素表明，2021年Fagradalsfjall熔岩既部分结晶，又受到强烈的地壳混染，即可能受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。最早喷发产物（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，在整个2021年喷发期间，Os同位素比值仍然升高，表明混染物持续存在，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大火爆发，涉及最早熔岩的喷发前停滞、分离结晶和地壳同化。2022年建立的岩浆通道系统使岩浆在没有地壳同化的情况下能够有效地向地表输送。

▲ 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.