《科学》（20230616出版）一周论文导读

编译 | 李言

Science, 16 JUN 2023, Volume 380 Issue 6650

《科学》2022年6月16日，第380卷，6650期

化学Chemistry

Modification of ground-state chemical reactivity via light–matter coherence in infrared cavities

通过红外腔中的光物质相干性改变基态化学反应性

▲ 作者：WONMI AHN, JOHAN F. TRIANA et al.

▲ 链接：

https://www.science.org/doi/10.1126/science.ade7147

▲ 摘要：

在这项研究中，我们从不断变化的腔透射光谱中提取了反应速率常数，揭示了环己醇对异氰酸苯酯醇解腔内反应速率的共振抑制。我们观察到，通过调整腔模式，使其与反应物异氰酸酯（NCO）、产物羰基（CO）和反应物-溶剂协同模式（CH）共振，可以达到高达80%的速率抑制。

我们用一个开放的量子系统模型来解释这些结果，该模型预测了来自规范统计的反应物的振动分布的共振修改，这是光物质量子相干的结果，表明了化学和量子科学之间的联系。

▲ Abstract：

In this work, reaction-rate constants were extracted from evolving cavity transmission spectra, revealing resonant suppression of the intracavity reaction rate for alcoholysis of phenyl isocyanate with cyclohexanol. We observed up to an 80% suppression of the rate by tuning cavity modes to be resonant with the reactant isocyanate (NCO) stretch, the product carbonyl (CO) stretch, and cooperative reactant-solvent modes (CH). These results were interpreted using an open quantum system model that predicted resonant modifications of the vibrational distribution of reactants from canonical statistics as a result of light–matter quantum coherences, suggesting links to explore between chemistry and quantum science.

Solvated dielectrons from optical excitation: An effective source of low-energy electrons

来自光激发的溶剂化介电子：低能电子的有效来源

▲ 作者：SEBASTIAN HARTWEG, JONATHAN BARNES, BRUCE L. YODER et al.

▲ 链接：

https://www.science.org/doi/10.1126/science.adh0184

▲ 摘要：

在这项研究中，我们展示了金属-氨簇的紫外线（UV）激发如何用于原位产生可调谐的低能电子。我们确定了紫外光诱导的自旋配对溶剂化二电子的产生，及其随后通过非常规电子转移介导的衰变可以作为有效的低能量电子源的弛豫。

这一过程是稳定且直接的，可以提高我们对辐射损伤的理解，以及促进溶剂化电子还原反应机理研究的前景。

▲ Abstract：

In this work, we show how ultraviolet (UV) photoexcitation of metal-ammonia clusters could be used to generate tunable low-energy electrons in situ. Specifically, we identified UV light–induced generation of spin-paired solvated dielectrons and their subsequent relaxation by an unconventional electron transfer–mediated decay as an efficient, low-energy electron source. The process is robust and straightforward to induce with the prospect of improving our understanding of radiation damage and fostering mechanistic studies of solvated electron reduction reactions.

材料科学Material Science

Size of cerium dioxide support nanocrystals dictates reactivity of highly dispersed palladium catalysts

二氧化铈载体纳米晶的大小决定了高度分散钯催化剂的反应性

▲ 作者：VALERY MURAVEV, ALEXANDER PARASTAEV et al.

▲ 链接：

https://www.science.org/doi/10.1126/science.adf9082

▲ 摘要：

在这里，我们证明了二氧化铈（CeO2）载体的大小决定了原子分散钯（Pd）在一氧化碳氧化中的反应性。

具有小型二氧化铈纳米晶（~4纳米）的催化剂在富含一氧化碳的反应中表现出异常高的活性，而具有中等大小二氧化铈纳米晶（~8纳米）的催化剂在缺乏一氧化碳的条件下更受青睐。详尽的光谱研究揭示了Pd- CeO2界面的支持尺寸依赖的氧化还原性质。

▲ Abstract：

Here, we demonstrate that the size of cerium dioxide (CeO2) support governs the reactivity of atomically dispersed palladium (Pd) in carbon monoxide (CO) oxidation. Catalysts with small CeO2 nanocrystals (~4 nanometers) exhibit unusually high activity in a CO-rich reaction feed, whereas catalysts with medium-size CeO2 (~8 nanometers) are preferred for lean conditions. Detailed spectroscopic investigations reveal support size–dependent redox properties of the Pd- CeO2 interface.

地球科学Geoscience

A younger and protracted emplacement of the Ontong Java Plateau

一个更晚、但更长的翁通爪哇海台形成时间

▲ 作者：PETER C. DAVIDSON, ANTHONY A. P. KOPPERS et al.

▲ 链接：

https://www.science.org/doi/10.1126/science.ade8666

▲ 摘要：

翁通爪哇海台（OJP）的海底火山被认为是海洋缺氧事件1a（OAE 1a）的成因。然而，鉴于OJP的形成时间和存在时间并不精确，它与OAE1a的联系分析主要依靠沉积记录中的代用物。我们提供来自OJP钻井和疏浚现场的高精度40Ar/39Ar数据，极大地精确了OJP的喷发历史记录。

从这项研究中，我们确定的OJP的形成时间比以往确认的晚1000万年，这表明了一个至少600万年的漫长形成期。现在，OJP看起来太“年轻”，不可能引发OAE1a，但我们认为它可能在后来的OAE1b中起作用。这种持久的持续喷发对OJP和其他大火成岩省的侵位动力学具有启示意义。

▲ Abstract：

The submarine volcanic emplacement of the Ontong Java Plateau (OJP) is the suggested cause of Ocean Anoxic Event 1a (OAE 1a). However, no precise timing and duration exists for the formation of OJP, and its connection to OAE1a relies mainly on proxies in the sedimentary record. We provide high-precision 40Ar/39Ar data from OJP drill and dredge sites that considerably improve OJP’s eruptive history. The ages determined from this work are as much as 10 million years younger than previous dates and indicate a protracted formation over at least 6 million years. OJP now appears too young to have caused OAE1a, but we suggest that it may have had a role in the later OAE1b. The protracted eruptive sequence has implications for the emplacement dynamics of OJP and other large igneous provinces.

生物学Biology

Aging Fly Cell Atlas identifies exhaustive aging features at cellular resolution

果蝇细胞衰老图谱揭示衰老特征

▲ 作者：TZU-CHIAO LU, MARIA BRBIĆ et al.

▲ 链接：

https://www.science.org/doi/10.1126/science.adg0934

▲ 摘要：

组织功能的衰弱是衰老的特征之一，但在整个生物体中细胞分辨率的潜在变化尚不清楚。在此，我们展示了果蝇细胞衰老图谱，一幅果蝇衰老全过程的单核转录组图谱。

我们鉴定了163种不同的细胞类型，并对组织细胞组成、基因表达和细胞身份的变化进行了深入分析。我们进一步开发了衰老时钟模型来预测果蝇的年龄，并表明核糖体基因表达是年龄的保守预测因素。结合所有衰老特征，我们发现了独特的细胞类型特异性衰老模式。这一图谱为研究复杂生物体衰老的基本原理提供了珍贵的资源材料。

▲ Abstract：

Aging is characterized by a decline in tissue function, but the underlying changes at cellular resolution across the organism remain unclear. Here, we present the Aging Fly Cell Atlas, a single-nucleus transcriptomic map of the whole aging Drosophila. We characterized 163 distinct cell types and performed an in-depth analysis of changes in tissue cell composition, gene expression, and cell identities. We further developed aging clock models to predict fly age and show that ribosomal gene expression is a conserved predictive factor for age. Combining all aging features, we find distinctive cell type–specific aging patterns. This atlas provides a valuable resource for studying fundamental principles of aging in complex organisms.

Widespread diversity deficits of coral reef sharks and rays

珊瑚礁鲨和鳐的广泛多样性不足

▲ 作者：COLIN A. SIMPFENDORFER, MICHAEL R. HEITHAUS et al.

▲ 链接：

https://www.science.org/doi/10.1126/science.ade4884

▲ 摘要：

我们的物种水平分析显示，5种常见的常驻礁鲨在全球范围内减少了60%至73%，而在34至47%被调查的珊瑚礁中没有检测到单个礁鲨物种。随着珊瑚礁中的鲨鱼越来越少，鳐鱼开始占据主导地位。

在治理高效的富裕国家和受高度保护的地区，鲨鱼主导的群落依旧存在。与此同时，贫穷、治理不力和缺乏鲨鱼管理等因素则与主要由鳐鱼组成的群落退化有关。如果不采取行动解决这些多样性缺陷，生态功能和生态系统服务的丧失将日益影响人类生活。

▲ Abstract：

Our species-level analysis revealed global declines of 60 to 73% for five common resident reef shark species and that individual shark species were not detected at 34 to 47% of surveyed reefs. As reefs become more shark-depleted, rays begin to dominate assemblages. Shark-dominated assemblages persist in wealthy nations with strong governance and in highly protected areas, whereas poverty, weak governance, and a lack of shark management are associated with depauperate assemblages mainly composed of rays. Without action to address these diversity deficits, loss of ecological function and ecosystem services will increasingly affect human communities.