《科學》（20240920出版）一周論文導讀

編譯|馮維維

Science,  VOLUME 385,ISSUE 6715,20 SEP 2024

《科學》第385卷，6715期，2024年9月20日

物理學Physics

Squeezing the quantum noise of a gravitational-wave detector below the standard quantum limit

將引力波探測器的量子噪聲壓縮到標準量子極限以下

▲ 作者：WENXUAN JIA , VICTORIA XU , KEVIN KUNS, MASAYUKI NAKANO, LISA BARSOTTI, MATTHEW EVANS, NERGIS MAVALVALA, AND MEMBERS OF THE LIGO SCIENTIFIC COLLABORATION

▲鏈接：

https://www.science.org/doi/10.1126/science.ado8069

▲摘要：

引力波探測器使用數公里長的干涉儀來測量時空的微小膨脹和收縮。由于量子力學的原因，這些測量的精度是有限的。理論上，利用光的壓縮態可以超越量子極限，而合適的濾光腔可以在更寬的頻率范圍內擴展這一優勢。

Jia等人測量了激光干涉引力波天文臺（LIGO）升級后的壓縮光和濾光腔系統的性能。研究證明，這些升級提高了探測器在寬頻率范圍內的靈敏度。在一個較小的范圍內，它超越了量子極限。

▲ Abstract：

Gravitational wave detectors use kilometers-long interferometers to measure tiny expansions and contractions of spacetime. The precision of those measurements is limited due to quantum mechanics. Theoretically, that quantum limit could be surpassed by using squeezed states of light, and a suitable filter cavity could extend the advantage over a wide frequency range. Jia et al. measured the performance of the Laser Interferometer Gravitational-Wave Observatory (LIGO) after it was upgraded with a squeezed light and filter cavity system. The authors demonstrate that the upgrades improved the sensitivity of the detector over a wide range of frequencies. Over a smaller range, it surpassed the quantum limit. 

Origin and fate of the pseudogap in the doped Hubbard model

摻雜哈伯德模型中贗隙的起源和命運

▲ 作者：FEDOR IMKOVIC IV, RICCARDO ROSSI, ANTOINE GEORGES, AND MICHEL FERRERO

▲鏈接：

https://www.science.org/doi/10.1126/science.ade9194

▲摘要：

盡管它很簡約，哈伯德模型卻能描述一些強相關物質的實例，但仍有一些在數值上難以解決的問題，將零溫度和有限溫度下的結果聯系起來尤其棘手。

Simkovic等人使用圖解蒙特卡羅計算來檢查在有限溫度下摻雜哈伯德模型中贗隙相的外觀。發現該相與反鐵磁自旋相關密切相關，并與零溫度下計算的基態條紋相相連。

▲ Abstract：

Despite its simplicity, the Hubbard model may be capable of describing some instances of strongly correlated matter. However, this remains difficult to solve numerically; connecting the results at zero and finite temperatures is particularly tricky. Simkovic et al. used diagrammatic Monte Carlo calculations to examine the appearance of the pseudogap phase in the doped Hubbard model at finite temperatures. This phase was found to be closely associated with antiferromagnetic spin correlations and to connect to the ground-state stripe phase calculated at zero temperature. 

化學Chemistry

Polyolefin waste to light olefins with ethylene and base-metal heterogeneous catalysts

用乙烯和賤金屬非均相催化劑將廢舊聚烯烴轉化為輕烯烴

▲ 作者：RICHARD J. CONK, JULES F. STAHLER, JAKE X. SHI, JI YANG, NATALIE G. LEFTON, JOHN N. BRUNN, ALEXIS T. BELL, AND JOHN F. HARTWIG

▲鏈接：

https://www.science.org/doi/10.1126/science.adq7316

▲摘要：

原則上，將塑料分解成其原始構件是一種理想的回收策略。但在實踐中，這種方法不可能用于目前使用的兩種最常見的塑料——聚乙烯和聚丙烯。因為相關反應在能耗上不占優勢。最近，幾組研究人員表明，用合適的催化劑引入新鮮的乙烯可以將聚烯烴轉化為丙烯，但用于催化的貴金屬價格過高。

現在Conk等人發現，可以在這個過程中使用地球上更豐富的氧化鎢和鈉的組合。研究表明，氧化鎢在二氧化硅上和鈉在γ-氧化鋁上的簡單組合將聚乙烯和聚丙烯或兩者的混合物轉化為丙烯或丙烯和異丁烯的混合物，在320°C下產量大于90%，而不需要對起始聚烯烴進行脫氫。

▲ Abstract：

Breaking down plastic into its original building blocks is an ideal recycling strategy in principle. Unfortunately, in practice, this approach isn’t possible for the two most common plastics currently in use, polyethylene and polypropylene, because the reaction is too energetically unfavorable. Very recently, several groups of researchers showed that introducing fresh ethylene with the right catalyst can transform polyolefins into propylene, but the precious metals used for the catalysis are prohibitively expensive. Conk et al. now report that the process works using a more Earth-abundant combination of tungsten oxide and sodium. The research shows that the simple combination of tungsten oxide on silica and sodium on gamma-alumina transforms PE, PP, or a mixture of the two, including postconsumer forms of these materials, to propylene or a mixture of propylene and isobutylene in greater than 90% yield at 320°C without the need for dehydrogenation of the starting polyolefins.

Radical-mediated click-clip reactions

介導的點擊反應

▲ 作者：JIANTAO ZHAO, HUACHENG YU, XINGCHEN JIN, BO QIN,SHAN MEI, JIANG-FEI XU,XI ZHANG

▲鏈接：

https://www.science.org/doi/10.1126/science.adn2259

▲摘要：

點擊化學是指在溫和條件下快速進行高轉化的偶聯反應，同時避免競爭途徑，產生相對較少的浪費。這種技術的主要缺點是，這些有利性質背后的強大驅動力往往會阻止可逆性。

Zhao等人報道了胺和吩噻嗪之間的氧化偶聯在室溫下表現出類似點擊的效率。然而，在近紫外照射下，產生的硫-氮鍵可以以相似的效率進行還原性裂解。

▲ Abstract：

Click chemistry refers to a growing class of coupling reactions that proceed rapidly to high conversion under mild conditions while avoiding competing pathways and generating relatively little waste. The main drawback to this technique is that the strong driving force underlying these favorable properties tends to prevent reversibility. Zhao et al. report an oxidative coupling between amines and phenothiazines that manifests click-like efficiency at room temperature. However, the resulting sulfur-nitrogen bond can be reductively cleaved with similar efficiency by irradiation in the near-ultraviolet range.

地球科學Geoscience

A 485-million-year history of Earth’s surface temperature

4.85億年歷史的地球表面溫度

▲ 作者：EMILY J. JUDD, JESSICA E. TIERNEY, DANIEL J. LUNT, ISABEL P. MONTAEZ, BRIAN T. HUBER, SCOTT L. WING, AND PAUL J. VALDES

▲鏈接

https://www.science.org/doi/10.1126/science.adk3705

▲摘要：

在過去的5億年里，動植物的進化模式對氣候的演變產生了重要影響。了解這一時期全球平均地表溫度（GMST）是如何變化的，對于理解這段時間內驅動氣候的過程至關重要。

Judd等人提出了將代理數據與氣候模擬相結合構建的過去4.85億年的GMST記錄。他們發現，全球平均地表溫度在11℃到36℃的范圍內變化，“表觀”氣候敏感性為~8℃，大約是今天的兩到三倍。

▲ Abstract：

Understanding how global mean surface temperature (GMST) has varied over the past half-billion years, a time in which evolutionary patterns of flora and fauna have had such an important influence on the evolution of climate, is essential for understanding the processes driving climate over that interval. Judd et al. present a record of GMST over the past 485 million years that they constructed by combining proxy data with climate modeling. They found that GMST varied over a range from 11°C to 36°C, with an “apparent” climate sensitivity of ～8°C, about two to three times what it is today. 

Atmospheric blocking slows ocean-driven melting of Greenland’s largest glacier tongue

大氣阻塞減緩格陵蘭島最大冰川舌的融化

▲ 作者：REBECCA ADAM MCPHERSON, CLAUDIA WEKERLE, TORSTEN KANZOW, MONICA IONITA, FINN OLE HEUKAMP, OLE ZEISING, AND ANGELIKA HUMBERT

▲鏈接：

https://www.science.org/doi/10.1126/science.ado5008

▲摘要：

近年來，格陵蘭島的冰川正在加速流失。McPherson等人發現，流入海洋的79號北冰川的融化近年來有所減緩。在冰排放地點的觀測顯示，從2018年到2021年，冰舌以下的水溫有所下降。

海洋熱輸送的減少歸因于北歐海周圍海洋環流的減緩和大西洋中間水的冷卻。這種減速是由歐洲大氣阻塞導致的，冷空氣通過弗拉姆海峽進入北極。

▲ Abstract：

Greenland has been experiencing accelerating glacier mass loss in recent years. McPherson et al. have found that melting of the 79 North Glacier, which discharges into the ocean, has been slowed somewhat in recent years. Observations at the site of ice discharge show that from 2018 to 2021, water temperatures below the ice tongue cooled. The reduction in ocean heat transport was attributed to a slowdown in ocean circulation around the Nordic seas and a cooling of the Atlantic Intermediate Water. This slowdown was driven by European atmospheric blocking that brought in cold Arctic air through the Fram Strait.