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《科学》(20260604出版)一周论文导读

 

编译|未玖

Science,科学 4 Jun 2026, VOL 392, ISSUE 6802

《科学》2026年6月4日,第392卷 ,出版6802期

地舆学Astronomy

A stellar dynamical mass measurement of an inactive black hole at redshift 2

红移2处一个休眠黑洞的周论恒星动力学质量测量

▲ 作者 :Andrew B. Newman, Meng Gu, Sirio Belli, Richard S. Ellis, Sai Gangula, Jenny E. Greene, et al.

▲链接:

https://www.science.org/doi/10.1126/science.adx5816

▲摘要 :

超除夜质量黑洞与其宿主星系随时分协同演变 ,由此在黑洞质量与多项星系物理参数之间产生发火相干性。文导断定这些相干性的读旧演变规律需求切确测量远远黑洞的质量  。

研究组独霸詹姆斯·韦伯太空看远镜的事科积分场光谱技能,对红移z=1.95处引力透镜活动星系MRG-M0138展开不美不美不雅察 ,学网以在空间上分析黑洞影响局限内恒星的科学行动学特点 。

借助前景引力透镜模型并拟合恒星动力学模型 ,出版研究组测得该休眠黑洞质量为M.=6.0+2.1-1.7×109倍太阳质量。周论将此下场与本土星系比照后创作创造:相较于星系核球质量M.值偏高;但与M.和恒星速度弥散之间的文导相干性齐截。

▲ Abstract:

Supermassive black holes and 读旧their host galaxies grow together over time, producing correlations between the black hole mass and various galaxy properties. Determining the evolution of these correlations requires precise measurements of the masses of distant black holes. We observed the gravitationally lensed quiescent galaxy MRG-M0138 at redshift 1.95 using James Webb Space Telescope integral field spectroscopy to spatially resolve the kinematics of stars within the black hole’s sphere of influence. By using a foreground lens model and fitting stellar dynamical models, we determined the mass of its inactive black hole to be M.=6.0+2.1-1.7×109solar masses. Comparing this measurement to local galaxies, we found that M. is higher than expected given the galaxy’s bulge mass but consistent with the correlation of M. with stellar velocity dispersion.

材料科学Materials Science

Ultralow chromium doping enables all-PbSe thermoelectric cooling

超低铬掺杂完成全PbSe热电冷却

▲ 作者:Shibo Liu, Yu Tian, Yi Wen, Shulin Bai, Bingchao Qin, Haonan Shi, et al.

▲链接:

https://www.science.org/doi/10.1126/science.aeg8963

▲摘要 :

热电冷却对固态热治理相当次要,但因为商用碲化铋器件中碲成本稀缺且成本昂扬,事科其除夜局限独霸遭到限制。学网

研究组基于全硒化铅(PbSe)材料 ,科学斥地出一种无碲热电冷却器 ,个中采取超低掺杂铬(Cr)网格  ,可以工程调控偏向和给体 ,优化了载流子输运,从而与n型和p型热电臂的功用相婚配。

研究组制备出具有协同婚配特点的高功用n型(PbSe+0.005Cr)和p型(PbSe+0.001Cr)晶体。该器件默示出出色的功用,具有更低的功耗和更高的制冷身手 ,在热端温度为363K时,冷却密度抵达约6W/cm2 ,峰值功用系数约为21 ,最除夜温差约为53K 。这些创作创造断定了PbSe可作为除夜局限冷却独霸中高效、可延续的更调材料  。

▲ Abstract :

Thermoelectric cooling is pivotal for solid-state thermal management, yet large-scale deployment is hindered by the scarcity and cost of tellurium in commercial bismuth telluride devices. We developed a tellurium-free thermoelectric cooler based on all lead selenide (PbSe), in which an ultralow-dopant chromium (Cr) grid allows the engineering of defects and donors to optimize carrier transport to match the performance of the n-type and p-type legs. We fabricated high-performance n-type (PbSe + 0.005Cr) and p-type (PbSe + 0.001Cr) crystals with synergistically matched properties. The device exhibits exceptional performance with lower power consumption and higher cooling capacity, achieving a cooling density of approximately 6 watts per square centimeter, a peak coefficient of performance of approximately 21, and a maximum temperature difference of approximately 53 kelvin at a 363-kelvin hot-side temperature. These findings establish PbSe as a highly effective, sustainable alternative for large-scale cooling applications.

Confined growth of armchair MoS2nanotubes at the 1-nm limit

1纳米极限下的扶手椅构型MoS2纳米管的限域展开

▲ 作者 :Yusuke Nakanishi, Ryosuke Senga, Shinpei Furusawa, Yuta Sato, Zheng Liu, Takumi Tanaka, et al.

▲链接:

https://www.science.org/doi/10.1126/science.aee3446

▲摘要:

半导体过渡金属二硫族化物的原子薄纳米管为在一维极限下试探量子气候和完成纳米标准晶体管沟道供给了平台 。可是,传统分化编制只能产生发火除夜直径(>10 nm)且手性不成控的多壁管 。

研究组报导了直径接近1 nm的单壁二硫化钼(MoS2)纳米管的分化  ,独霸氮化硼(BN)纳米管内部的空间限域回响完成 。这类限域若干很多若干筹划晃荡了本来没法掉落踪掉落踪、且高度应变的MoS2纳米管 ,从而构成筹划了了的扶手椅构型。

跟着直径减小 ,其带隙产生发火琐细性膨胀 ,这与经久以来的幻想料想齐截。同时,尽缘的BN包覆层供给了一种天然的旋绕栅极架构 ,有看完成真正意义上的纳米标准晶体管沟道。

▲ Abstract:

Atomically thin nanotubes of semiconducting transition metal dichalcogenides offer a platform for exploring quantum phenomena at the one-dimensional limit and for realizing nanoscale transistor channels. However, conventional syntheses produce only large-diameter (>10 nm), multiwalled tubes with uncontrolled chiralities. We report the synthesis of single-walled molybdenum disulfide (MoS2) nanotubes with diameters approaching 1 nm, achieved through spatially confined reactions inside boron nitride (BN) nanotubes. The confined geometry stabilizes otherwise inaccessible, highly strained MoS2nanotubes, yielding structurally well-defined armchair configurations. Their bandgaps shrink systematically with decreasing diameter, in accordance with long-standing theoretical predictions. The insulating BN sheath simultaneously provides an intrinsic gate-all-around architecture, thereby promising access to truly nanoscale transistor channels.

化学Chemistry

Photocatalyzed oxidative cleavage of alkenes using CO2as an oxygen donor

以CO2为氧供体的烯烃光催化氧化裂解

▲ 作者:Yuman Qin, Peng Ren, Jun Hu, Suman Pradhan, Thanh Huyen Vuong, Xiufang He, et al.

▲链接:

https://www.science.org/doi/10.1126/science.aed6068

▲摘要 :

碳-碳双键的氧化裂解但凡需求毁伤的试剂和苛刻的前提 。

研究组报导了将次要二氧化碳(CO2)作为氧供体 ,在室次要常压下完成烯烃的光催化氧化裂解 ,生成酮或羧酸 。即采取一种安妥的铁基非均相光催化剂  ,促进氧原子转移构成环氧化物中心体 ,随后产生发火开环和碳-碳键断裂,以高选择性地掉落踪掉落踪氧化产品。

综合机理研究连络了时分分辨光谱 、同位素标识表记标帜 、原位光谱分化和进步先辈的量子力学模仿 。这些下场揭穿了光催化前提下CO2氧原子转移的基身手理 ,为光驱动的氧化转化供给了一个可延续的平台  。

▲ Abstract:

Oxidative cleavage of carbon-carbon double bonds often requires hazardous reagents and demanding conditions. In this study, we report a photocatalytic oxidative cleavage of alkenes using benign carbon dioxide (CO2) as an oxygen donor, producing ketones or carboxylic acids at atmospheric pressure and room temperature. A robust iron-based heterogeneous photocatalyst facilitates oxygen transfer to form an epoxide intermediate that subsequently undergoes ring opening and carbon-carbon bond cleavage to yield the oxidative products with high selectivity. Comprehensive mechanistic studies combine time-resolved spectroscopy, isotope labeling, and in situ spectroscopic analyses with advanced quantum mechanical simulations. These results uncover fundamental principles of oxygen transfer from CO2under photocatalytic conditions, offering a sustainable platform for light-driven oxidative transformations.

Stereoretentive radical-based alkyl-alkyl cross-coupling

可贯穿连接立体构型的逍遥基烷基-烷基交错偶联回响

▲ 作者:Yu Wang, Jiawei Sun, Yin Li, David A. Cagan, Oliver T. Ring, Xin Zeng, et al.

▲链接 :

https://www.science.org/doi/10.1126/science.aef6981

▲摘要 :

因为存在竞争性的β-氢消弭和本身偶联回响 ,和逍遥基路途固有的较差立体独霸身手,经由过程交错偶联构建具有立体构型的C(sp3)-C(sp3)键仍颇具挑衅。

研究组报导了一种可放除夜且可贯穿连接立体构型的逍遥基-逍遥基交错偶联回响 ,该回响将两种不合的瞬态烷基逍遥基(分袂源于富对映体的磺酰肼和非手性的一级及二级烷基卤化物)在无需手性配体、导向基团或外源氧化恢复试剂的前提下完成偶联。

这类底物独霸计策采取了一种镍催化的氧化恢复中性琐细,可以完成对二氮烯介导的逍遥基生成与卤原子转移的切确动力学婚配。该回响在多种哌啶和吡咯烷骨架筹划上完成了80%至96%的对映体特异性和分化有效产率(高达90%) ,同时兼容醚 、游离胺、芳基卤化物、杂环 、烯烃及其他敏感基序。

机理研究支撑经由过程笼内逍遥基回弹到镍中心来贯穿连接办性,随后经镍(I)-镍(III)介导的逍遥基捕获和恢复消弭完成回响 。

▲ Abstract:

The construction of stereogenic C(sp3)–C(sp3) bonds through cross-coupling remains a formidable challenge owing to competing β-hydride elimination and homocoupling as well as the poor inherent stereocontrol of radical pathways. In this work, we report a scalable stereoretentive radical-radical cross-coupling of two distinct, transient alkyl radicals, derived from enantioenriched sulfonylhydrazides and achiral primary and secondary alkyl halides, achieved without chiral ligands, directing groups, or exogenous redox agents. This substrate-controlled approach leverages a nickel-catalyzed, redox-neutral manifold, which enables precise kinetic matching of diazene-mediated radical generation and halogen atom transfer. The reaction produced enantiospecificities of 80 to 96% and synthetically useful yields (up to 90%) across diverse piperidine and pyrrolidine scaffolds while tolerating ethers, free amines, aryl halides, heterocycles, olefins, and other sensitive motifs. Mechanistic studies support caged radical rebound at nickel to preserve chirality, followed by nickel(I)-nickel(III)–mediated radical capture and reductive elimination.

地球科学Earth Science

Fires reverse progress toward ozone air quality standards in the United States

野火逆转了美国臭氧氛围质量标准的治理成效

▲ 作者:Weizhi Deng, Jun Wang, Meng Zhou, Xi Chen, Xiaodong Wu, Huanxin Zhang, et al.

▲链接:

https://www.science.org/doi/10.1126/science.aed3197

▲摘要 :

比来几年来野火排放激添加重了美国的地表臭氧净化 。研究组依托深度进修技能  ,构建了2003-2024年1千米分辨率的无间隙每日地表臭氧数据集 。该数据集揭穿了受限于稀少监测群集而未创作创造的国度政策相干臭氧趋势的逆转 :从每年-0.65 ppb(2003-2015)到每年+0.13 ppb(2015-2024) 。

该逆转次要由野火排放量爬升主导 ,抵消了长达3.9年的臭氧减排成效 。2013年起 ,野火产生发火的臭氧每年出格构成318人过早鼓起;2013年后相干致作前人数较此前添加46%。2022-2024年间 ,野火排放招致4300万群众泄漏在臭氧超标气候中 ,直接劝止了臭氧氛围质量标准收紧4ppb的政策落地。

上述研究下场注解,在气候笼统改削驱动野火频发加重的除夜布景下,贯穿连接氛围质量改进下场正面对日趋严重的挑衅。

▲ Abstract:

Recent surges in wildfire emissions have exacerbated su***ce ozone pollution in the United States. Using deep learning, we developed a gapless daily su***ce ozone dataset at 1-kilometer resolution for 2003–2024. This dataset revealed a reversal in national policy–relevant ozone trends that had gone undetected by the sparse monitoring network: from 0.65 parts per billion (ppb) per year (2003–2015) to +0.13 ppb per year (2015–2024). The reversal was primarily driven by increasing wildfire emissions, offsetting 3.9 years of mitigation progress. Premature deaths from fire-sourced ozone have increased by 318 deaths per year since 2013, with post-2013 mortality 46% higher than pre-2013 mortality. During 2022–2024, wildfire emissions exposed 43 million people to nonattainment conditions, effectively preventing a 4-ppb tightening of the ozone standard. These results underscore the growing challenges of sustaining air quality progress as wildfires intensify under climate change.

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