《科学》（20220909出版）一周论文导读
2022/9/11 20:08:21 科学网

     编译 | 李言

     Science, 9 Sep 2022, VOLUME 377 ISSUE 6611

     《科学》2022年9月9日，第377卷，6611期

    

     天文学Astronomy

     Density, not radius, separates rocky and water-rich small planets orbiting M dwarf stars

     密度，而不是半径，区分了围绕矮星运行的岩质行星和富水行星

     ▲ 作者：RAFAEL LUQUE AND ENRIC PALLé

     ▲ 链接：

     https://www.science.org/doi/10.1126/science.abl7164

     ▲ 摘要：

     比海王星小的系外行星通常围绕红矮星旁，它们和那些经过它们的主星的行星一同构成了符合大气特征的已知温带世界的大部分。我们分析了所有已知的围绕M矮星的小型凌日行星的质量和半径，确定了三个种：岩质行星、富水行星和富气行星。

     我们的结果与先前对于双峰半径分布源于大气损失的氢/氦包层的这一认知不一致。相反，我们提出是密度差异将岩质行星及富水行星区分开来。包含轨道迁移的形成模型可以解释这些观测结果：岩质行星在雪线内形成，而富水行星在雪线外形成，然后向内迁移。

     ▲ Abstract：

     Exoplanets smaller than Neptune are common around red dwarf stars (M dwarfs), with those that transit their host star constituting the bulk of known temperate worlds amenable for atmospheric characterization. We analyze the masses and radii of all known small transiting planets around M dwarfs, identifying three populations: rocky, water-rich, and gas-rich. Our results are inconsistent with the previously known bimodal radius distribution arising from atmospheric loss of a hydrogen/helium envelope. Instead, we propose that a density gap separates rocky from water-rich exoplanets. Formation models that include orbital migration can explain the observations: Rocky planets form within the snow line, whereas water-rich worlds form outside it and later migrate inward.

     物理学Physics

     Chiral emission from resonant metasurfaces

     共振超表面手性发射

     ▲ 作者：XUDONG ZHANG, YILIN LIU et al.

     ▲ 链接：

     https://www.science.org/doi/10.1126/science.abq7870

     ▲ 摘要：

     超紧凑型圆偏振光在经典和量子光学信息处理中具有重要意义。传统的手性发射产生方法受到激发功率范围的限制，不能提供具有完美极化转换的高质量辐射。

     我们利用手性准束缚态在连续介质中的物理特性，证明了共振超表面圆偏振光的有效和可控发射。利用本征手性和巨场增强，我们揭示了如何在没有自旋注入的情况下同时修改和控制光致发光和激光的光谱、辐射模式和自旋角动量。手性发射和激光的优越特性为纳米光子学和量子光学提供了多种应用前景。

     ▲ Abstract：

     Ultracompact sources of circularly polarized light are important for classical and quantum optical information processing. Conventional approaches for generating chiral emission are restricted to excitation power ranges and fail to provide high-quality radiation with perfect polarization conversion. We used the physics of chiral quasi-bound states in the continuum to demonstrate the efficient and controllable emission of circularly polarized light from resonant metasurfaces. Exploiting intrinsic chirality and giant field enhancement, we revealed how to simultaneously modify and control spectra, radiation patterns, and spin angular momentum of photoluminescence and lasing without any spin injection. The superior characteristics of chiral emission and lasing promise multiple applications in nanophotonics and quantum optics.

     Systematic electronic structure in the cuprate parent state from quantum many-body simulations

     量子多体模拟中铜母态的系统电子结构

     ▲ 作者：ZHI-HAO CUI, HUANCHEN ZHAI et al.

     ▲ 链接：

     https://www.science.org/doi/10.1126/science.abm2295

     ▲ 摘要：

     相关电子材料的定量描述仍然是现代计算的一个挑战。我们展示了一种数值策略，在完全从头算的水平上模拟相关材料，超出了有效的低能模型的解，并应用它来获得对母体未掺杂态的铜类超导材料家族的详细微观理解。

     我们揭示了电子相关性的微观趋势，并通过涉及缓冲层的激发过程的多体图像揭示了材料组成和磁能尺度之间的联系。我们的工作阐明了一条从头计算多体水平对相关材料的更复杂状态进行定量和可靠理解的道路。

     ▲ Abstract：

     The quantitative description of correlated electron materials remains a modern computational challenge. We demonstrate a numerical strategy to simulate correlated materials at the fully ab initio level beyond the solution of effective low-energy models and apply it to gain a detailed microscopic understanding across a family of cuprate superconducting materials in their parent undoped states. We uncover microscopic trends in the electron correlations and reveal the link between the material composition and magnetic energy scales through a many-body picture of excitation processes involving the buffer layers. Our work illustrates a path toward a quantitative and reliable understanding of more complex states of correlated materials at the ab initio many-body level.

     化学Chemistry

     Hydroformylation catalyzed by unmodified cobalt carbonyl under mild conditions

     在温和条件下由未改性的羰基钴催化的氢甲酰化反应

     ▲ 作者：BAOXIN ZHANG, CHRISTOPH KUBIS et al.

     ▲ 链接：

     https://www.science.org/doi/10.1126/science.abm4465

     ▲ 摘要：

     在此，我们报告，未改性的羰基钴在140°C 的30 bar合成气压力下是一种稳定的氢甲酰化催化剂。活性可与最近报告的双膦配位钴(II)催化剂相比，但我们无法在报告的条件下复制。

     动力学和原位红外光谱研究证实了未修饰钴四羰基氢化物[HCo(CO)₄]的稳定性。在没有磷配体的情况下，在低的合成气压力下，支链内烯烃转化为具有高区域选择性的醛。当磷钴负载比低于0.6时，双膦对催化剂的促进作用较小。

     ▲ Abstract：

     We report here that unmodified cobalt carbonyl is a stable hydroformylation catalyst at 140°C under 30 bar of syngas. The activity was comparable to that of recently reported bisphosphine-coordinated cobalt(II) catalysts, which we could not reproduce under the reported conditions. Kinetic and in situ infrared spectroscopic studies confirmed the stability of the unmodified cobalt tetracarbonyl hydride [HCo(CO)₄]. Branched internal olefins were converted to aldehydes with high regioselectivity under low syngas pressures without phosphorus ligands. Bisphosphines had a small promotional effect on the catalyst at phosphorus-to-cobalt loading ratios below 0.6.

     地球科学Earth Science

     Exceeding 1.5°C global warming could trigger multiple climate tipping points

     全球变暖超过1.5°C可能引发多个气候临界点

     ▲ 作者：DAVID I. ARMSTRONG MCKAY, ARIE STAAL et al.

     ▲ 链接：

     https://www.science.org/doi/10.1126/science.abn7950

     ▲ 摘要：

     当气候系统的一部分变化超过变暖阈值时，就会出现气候临界点，导致对地球系统的重大影响。综合古气候、观测研究和基于模型的研究，我们提供了一份全球“临界”要素和区域“影响”临界要素及其温度阈值修订候选名单。

     目前的全球变暖比工业化前的温度高出1.1°C，已经处于某些临界点不确定性范围的边缘。在《巴黎协定》中规定的全球变暖1.5到2°C的范围内，可能会触发几个临界点，而根据目前的政策轨迹，温度上升2到3°C时会触发更多临界点。这加强了采取紧急行动减缓气候变化和制定改进临界点风险评估、预警能力和适应战略的证据基础。

     ▲ Abstract：

     Climate tipping points occur when change in a part of the climate system becomes self-perpetuating beyond a warming threshold, leading to substantial Earth system impacts. Synthesizing paleoclimate, observational, and model-based studies, we provide a revised shortlist of global “core” tipping elements and regional “impact” tipping elements and their temperature thresholds. Current global warming of ~1.1°C above preindustrial temperatures already lies within the lower end of some tipping point uncertainty ranges. Several tipping points may be triggered in the Paris Agreement range of 1.5 to<2°C global warming, with many more likely at the 2 to 3°C of warming expected on current policy trajectories. This strengthens the evidence base for urgent action to mitigate climate change and to develop improved tipping point risk assessment, early warning capability, and adaptation strategies.

     动物学Zoology

     The genomic history and global expansion of domestic donkeys

     家驴的基因组历史和全球扩张

     ▲ 作者：EVELYN T. TODD, LAURE TONASSO-CALVIèRE, LORELE? CHAUVEY et al.

     ▲ 链接：

     https://www.science.org/doi/10.1126/science.abo3503

     ▲ 摘要：

     驴改变了人类的历史。它们成为长距离迁徙必不可少的驮兽，尤其是穿越半干旱和高地环境。对它们的研究仍然不足，尽管它们的族群在全球范围内不断扩大，并为中低收入社区提供了关键支持。为了阐明家驴的驯化历史，我们构建了207头现代驴子和31头古代驴子以及15头野生马科动物的全面基因组面板。

     我们在现代家驴的基因中发现了强大的系统地理结构支持这一观点：公元前5000年曾在非洲的发生了一次驯化过程，随后族群在这片大陆和欧亚大陆进一步扩张，最终回到非洲。我们在公元前200年的黎凡特发现了一个以前未知的遗传谱系，这有助于增加对亚洲祖先驴的认识。在那个骡子对罗马经济和军事至关重要的时代，对驴的管理包括近亲繁殖和培育更大体型。

     ▲ Abstract：

     Donkeys transformed human history as essential beasts of burden for long-distance movement, especially across semi-arid and upland environments. They remain insufficiently studied despite globally expanding and providing key support to low- to middle-income communities. To elucidate their domestication history, we constructed a comprehensive genome panel of 207 modern and 31 ancient donkeys, as well as 15 wild equids. We found a strong phylogeographic structure in modern donkeys that supports a single domestication in Africa ~5000 BCE, followed by further expansions in this continent and Eurasia and ultimately returning to Africa. We uncover a previously unknown genetic lineage in the Levant ~200 BCE, which contributed increasing ancestry toward Asia. Donkey management involved inbreeding and the production of giant bloodlines at a time when mules were essential to the Roman economy and military.

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