《科学》（20230609）一周论文导读

编译 | 冯维维

SCIENCE, VOLUME 380|ISSUE 6649|9 JUN 2023

《科学》第380卷，6649期，2023年6月9日

物理学Physics

Constraints on the Hubble constant from supernova Refsdal’s reappearance

超新星雷夫斯达尔再现对哈勃常数的限制

▲ 作者：PATRICK L. KELLY, STEVEN RODNEY, TOMMASO TREU, MASAMUNE OGURI, WENLEI CHEN, ADI ZITRIN, SIMON BIRRER, VIVIEN BONVIN, LUC DESSART, AND ANJA VON DER LINDEN

▲ 链接：

https://www.science.org/doi/10.1126/science.abh1322

▲ 摘要：

哈勃常数测量宇宙的膨胀率，但不同的方法给出的值不一致。Kelly等研究了一颗超新星，它的光被前景星系团的引力透镜分裂成多个图像。

研究者将多幅图像之间的时间延迟测量结果与星团的多个透镜模型做出的预测相结合。这种方法允许研究者对哈勃常数进行盲法测量，发现一个更符合宇宙微波背景而不是宇宙距离阶梯的值。

▲ Abstract：

The Hubble constant measures the expansion rate of the Universe, but different methods give inconsistent values. Kelly et al. studied a supernova that had its light split into multiple images by the gravitational lensing of a foreground galaxy cluster. They combined measurements of the time delay between the multiple images with predictions made by multiple lensing models of the cluster. This approach allowed the authors to make a blinded measurement of the Hubble constant, finding a value that is more consistent with that derived from the cosmic microwave background than with the cosmic distance ladder.

Splitting phonons: Building a platform for linear mechanical quantum computing

分裂声子：构建线性力学量子计算平台

▲ 作者：H. QIAO, é. DUMUR, G. ANDERSSON, H. YAN, M.-H. CHOU, J. GREBEL, C. R. CONNER, Y. J. JOSHI, J. M. MILLER, AND A. N. CLELAND

▲ 链接：

https://www.science.org/doi/10.1126/science.adg8715

▲ 摘要：

声子是材料内部的基本量子振动，单个声子代表了数万亿原子的集体运动。科学家正在努力确定这些机械振动是否可以发展成量子计算架构，就像它们的光学表亲——光子一样。

研究者演示了一种用于单声子和可控双声子干涉的分束器。除了发射和探测单个声子的能力之外，分束器现在为开发基于机械的量子计算平台提供了工具箱中的最后一部分。

▲ Abstract：

Phonons are the fundamental quantum vibrations within materials, with individual phonons representing the collective motion of many trillions of atoms. Efforts are underway to determine whether these mechanical vibrations can be developed into a quantum-computing architecture just like their optical cousin, photons. Qiao et al. demonstrate a beam splitter for single phonons and controlled two-phonon interference. Adding to the ability to launch and detect single phonons, a beam splitter now provides the final piece in the toolbox to develop a mechanically based platform for quantum computing.

物理化学Physical Chemistry

Atomic-scale polarization switching in wurtzite ferroelectrics

纤锌矿铁电体的原子尺度极化开关

▲ 作者：SEBASTIAN CALDERON V, JOHN HAYDEN, STEVEN M. BAKSA, WILLIAM TZOU, SUSAN TROLIER-MCKINSTRY, ISMAILA DABO, JON-PAUL MARIA, AND ELIZABETH C. DICKEY

▲ 链接：

https://www.science.org/doi/10.1126/science.adh7670

▲ 摘要：

氮基铁电纤锌矿是一种新兴的晶体家族，作为现代微电子学的开关材料非常有吸引力。这些材料的化学性质与目前的半导体平台非常匹配。

Calderon等人使用一系列表征工具来准确确定由铝、硼和氮组成的代表性纤锌矿是如何经历极化开关的。更详细地了解这一过程对于降低这些材料在其中转换的电场至关重要，因为这是它们应用中的限制因素。

▲ Abstract：

Nitride-based ferroelectric wurtzites are an emerging family of crystals that are highly attractive as switching materials for modern microelectronics. The chemistry of these materials is a good match for current semiconductor platforms. Calderon et al. used an array of characterization tools to determine exactly how a representative wurtzite composed of aluminum, boron, and nitrogen undergoes polarization switching. A more detailed understanding of this process is vital for lowering the electric field under which these materials switch, because this is a limiting factor in moving them into applications.

Synthesis and isolation of a triplet bismuthinidene with a quenched magnetic response

磁猝灭三重态铋的合成与分离

▲ 作者：YUE PANG, NILS NÖTHLING, MARKUS LEUTZSCH, LIQUN KANG, ECKHARD BILL, MAURICE VAN GASTEL, EDWARD REIJERSE, RICHARD GODDARD, LUCAS WAGNER, AND JOSEP CORNELLA

▲ 链接：

https://www.science.org/doi/10.1126/science.adg2833

▲ 摘要：

铋通常与至少三个其他原子配位。Pang等人报道了一种不寻常的化合物的合成和结晶，其中一价铋中心仅与单个笨重的碳配体结合。

虽然理论预测这个成键基序应该在三重态中留下两个未配对的电子，但化合物并没有表现出顺磁响应。研究者将这一观察结果归因于重元素固有的大自旋轨道耦合对最低磁亚能级的热隔离。

▲ Abstract：

Bismuth conventionally coordinates to at least three other atoms. Pang et al. report the synthesis and crystallization of an unusual compound in which a monovalent bismuth center is bonded to just a single bulky carbon ligand. Although theory predicts that this bonding motif should leave two electrons unpaired in a triplet state, the compound did not exhibit a paramagnetic response. The authors attribute this observation to thermal isolation of the lowest magnetic sublevel by the large spin-orbit coupling intrinsic to heavy elements.

气候学Climatology

Persistent effect of El Niño on global economic growth

厄尔尼诺对全球经济增长的持续影响

▲ 作者：CHRISTOPHER W. CALLAHAN AND JUSTIN S. MANKIN

▲ 链接：

https://www.science.org/doi/10.1126/science.adf2983

▲ 摘要：

厄尔尼诺-南方涛动（ENSO）在全球范围内塑造了极端天气，造成了无数的社会经济影响，但经济是否能从ENSO事件中恢复，以及ENSO的人为变化将如何影响全球经济，这些都是未知的。CALLAHAN等研究表明厄尔尼诺可持续降低国家层面的经济增长。

作者认为1982~1983年和1997~1998年的厄尔尼诺事件分别导致4.1万亿美元和5.7万亿美元的全球收入损失。在与当前减排承诺相一致的排放情景中，预计ENSO幅度的增加和变暖带来的遥相关将在21世纪造成84万亿美元的经济损失，这些影响是由厄尔尼诺和拉尼娜事件序列的随机变化形成的。研究结果强调了经济对独立于变暖的气候变率的敏感性，以及由于这种变率的人为加剧而造成的未来损失的可能性。

▲ Abstract：

The El Niño–Southern Oscillation (ENSO) shapes extreme weather globally, causing myriad socioeconomic impacts, but whether economies recover from ENSO events and how anthropogenic changes to ENSO will affect the global economy are unknown. Here we show that El Niño persistently reduces country-level economic growth; we attribute $4.1 trillion and $5.7 trillion in global income losses to the 1982–83 and 1997–98 El Ni?o events, respectively. In an emissions scenario consistent with current mitigation pledges, increased ENSO amplitude and teleconnections from warming are projected to cause $84 trillion in 21st-century economic losses, but these effects are shaped by stochastic variation in the sequence of El Niño and La Niña events. Our results highlight the sensitivity of the economy to climate variability independent of warming and the potential for future losses due to anthropogenic intensification of such variability.

Limited climatic space for alternative ecosystem states in Africa

非洲气候空间变化驱动植被格局变化

▲ 作者：STEVEN I. HIGGINS, TIMO CONRADI, LAURENCE M. KRUGER, ROBERT B. O’HARA, AND JASPER A. SLINGSBY

▲ 链接：

https://www.science.org/doi/10.1126/science.add5190

▲ 摘要：

植被类型在全球范围内的分布是由气候决定的，但在局部或区域尺度上，由于过去的干扰和物种相互作用，可能会出现非常不同的植被。Higgins等人研究了气候在预测热带和亚热带非洲森林和稀树草原分布方面的作用。

利用植被图数据，研究者对9000多种植物物种进行了生态位预测，并对主要生长形式进行了气候适宜性估计。该模型对森林和稀树草原的预测精度较高，表明气候的空间变化同时驱动大尺度和相对精细尺度的植被格局。因此，气候变化对非洲森林和稀树草原分布的影响可能比以前认识到的更容易预测。

▲ Abstract：

The distribution of vegetation types across the globe is determined by climate, but at the local or regional scale, very different vegetation can occur depending on past disturbances and species interactions. Higgins et al. investigated how well climate alone can predict the distribution of forest and savanna across tropical and subtropical Africa. Using vegetation plot data, the authors created niche projections for more than 9000 plant species and climate suitability estimates for major growth forms. The resulting model predicted forest versus savanna occurrence with high accuracy, suggesting that spatial variation in climate drives both large-scale and relatively fine-scale vegetation patterns. The effects of climate change on the distribution of African forest and savanna may thus be more predictable than has previously been recognized.