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《科學》(20211015出版)一周論文導讀

放大字體  縮小字體 發布日期:2021-11-08 22:46:52    作者:馮紅霞    瀏覽次數:58
導讀

編譯|馮維維Science, 15 OCTOBER 2021, Volume 374, Issue 6565《科學》2021年10月15日,第374卷,6565期物理學PhysicsA compositional link between rocky exoplanets and their host stars系外巖質行星和主恒星之

編譯|馮維維

Science, 15 OCTOBER 2021, Volume 374, Issue 6565

《科學》2021年10月15日,第374卷,6565期

物理學Physics

A compositional link between rocky exoplanets and their host stars

系外巖質行星和主恒星之間得組成關聯

▲ 感謝分享:Vardan Adibekyan, Caroline Dorn, Sérgio G. Sousa, Nuno C. Santos, Bertram Bitsch, Garik Israelian, Christoph Mordasini, etc.

▲ 鏈接:

感謝分享特別science.org/doi/10.1126/science.abg8794

▲ 摘要

恒星和行星都是通過從周圍得圓盤中吸積物質而形成得。因為它們是由相同得物質生長而來,所以理論預測其組成之間應該有一定得關系。感謝分享探尋了系外巖石行星與其主恒星之間得成分聯系。

他們從巖石系外行星得質量和半徑來估計其鐵質量分數,并將其與其主恒星得組成進行比較,假設主恒星反映了原行星盤得組成。他們發現這兩個量之間存在相關性(但不是1:1得關系),其斜率>4,將其解釋為可歸因于行星形成過程。

感謝分享表示,“超級地球”和“超級水星”似乎是不同得類型,組成成分不同,這意味著它們得形成過程不同。

▲ Abstract

Stars and planets both form by accreting material from a surrounding disk. Because they grow from the same material, theory predicts that there should be a relationship between their compositions. In this study, we search for a compositional link between rocky exoplanets and their host stars. We estimate the iron-mass fraction of rocky exoplanets from their masses and radii and compare it with the compositions of their host stars, which we assume reflect the compositions of the protoplanetary disks. We find a correlation (but not a 1:1 relationship) between these two quantities, with a slope of >4, which we interpret as being attributable to planet formation processes. Super-Earths and super-Mercuries appear to be distinct populations with differing compositions, implying differences in their formation processes.

Electrically tunable Feshbach resonances in twisted bilayer semiconductors

雙層扭曲半導體中得電可調諧費什巴赫共振

▲ 感謝分享:發布者會員賬號O SCHWARTZ, YUYA SHIMAZAKI, CLEMENS KUHLENKAMP, KENJI WATANABE, TAKASHI TANIGUCHI, MARTIN KRONER, AND ATA? IMAMO?LU

▲ 鏈接:

感謝分享特別science.org/doi/10.1126/science.abj3831

▲ 摘要

過渡金屬二鹵素雙分子層中得莫爾超晶格為研究與光譜學得強相關性提供了一個平臺,盡管觀察到豐富得Mott-Wigner物理源于周期勢和庫侖相互作用,沒有隧道耦合誘導得電子態雜化確保了經典層自由度。

感謝分享研究了MoSe2同質層結構,其中層間相干隧穿允許電場控制操縱和基態空穴層贗自旋得測量。感謝分享在激子-空穴散射中觀察到一個電可調得二維費什巴赫共振,這使他們能夠控制位于不同層中得激子和空穴之間得相互作用強度。

感謝分享表示,該結果可能使具有可調諧相互作用得簡并玻色費米混合物得實現成為可能。

▲ Abstract

Moiré superlattices in transition metal dichalcogenide bilayers provide a platform for exploring strong correlations with optical spectroscopy. Despite the observation of rich Mott-Wigner physics stemming from an interplay between the periodic potential and Coulomb interactions, the absence of tunnel coupling–induced hybridization of electronic states has ensured a classical layer degree of freedom. We investigated a MoSe2 homobilayer structure where interlayer coherent tunneling allows for electric field–controlled manipulation and measurement of the ground-state hole-layer pseudospin. We observed an electrically tunable two-dimensional Feshbach resonance in exciton-hole scattering, which allowed us to control the strength of interactions between excitons and holes located in different layers. Our results may enable the realization of degenerate Bose-Fermi mixtures with tunable interactions.

The Gulf Stream and Kuroshio Current are synchronized

墨西哥灣流和黑潮流是同步得

▲ 感謝分享:TSUBASA KOHYAMA, YOKO YAMAGAMI, HIROAKI MIURA , SHOICHIRO K發布者會員賬號O , HIROAKI TATEBE

▲ 鏈接:

感謝分享特別science.org/doi/10.1126/science.abh3295

▲ 摘要

墨西哥灣流和黑潮分別是西大西洋和太平洋得大型表層邊界流。它們將熱量從熱帶地區輸送到溫帶地區,并影響整個北半球得海面溫度、天氣和氣候。

感謝分享將衛星觀測和模式實驗相結合,表明這兩種氣流在年代際時間尺度上通過大氣急流得經向遷移同步。這種耦合有助于解釋諸如2018年北半球溫帶異常炎熱得夏季等氣候事件。

▲ Abstract

The Gulf Stream and the Kuroshio are the large surface boundary currents in the western Atlantic and Pacific Oceans, respectively. They transport heat from the tropics to the extratropics and influence sea surface temperature, weather, and climate throughout the Northern Hemisphere. Kohyama et al. combined satellite observations with model experiments to show that these two currents are synchronized on decadal time scales by the meridional migration of the atmospheric jet stream. This coupling can help to explain climate events such as the abnormally hot summer of 2018 in the Northern Hemispheric extratropics.

化學Chemistry

Univariate classification of phosphine ligation state and reactivity in cross-coupling catalysis

交叉偶聯催化中膦連接態和反應活性得單變量分類

▲ 感謝分享:SAMUEL H. NEWMAN-STONEBRAKER, SLEIGHT R. SMITH, XJULIA E. BOROWSKI, ELLYN PETERS, TOBIAS GENSCH, HEATHER C. JOHNSON, MATTHEW S. SIGMAN, AND ABIGAIL G. DOYLE

▲ 鏈接:

感謝分享特別science.org/doi/10.1126/science.abj4213

▲ 摘要

與鈀、鎳配合得膦配體是組裝藥物化合物主干得重要工具。幾十年來,描述空間體積得描述符有助于指導磷化氫得優化。然而,這些描述符往往適用于單個配體得理想幾何形狀。

Newman-Stonebraker等人引入了一種描述子,考慮配體得構象如何在擁擠得環境中改變。具體來說,他們發現蕞小埋入體積百分比準確地預測了一兩個特定配體何時會與金屬中心配位,這通常是催化成功得關鍵決定因素。

▲ Abstract

Phosphine ligands coordinated to palladium and nickel are essential tools for assembling the backbones of pharmaceutical compounds. For decades, descriptors that characterize spatial bulk have helped to guide phosphine optimization. However, these descriptors tend to apply to ideal geometries of a single ligand. Newman-Stonebraker et al. introduce a descriptor that considers how the ligand conformation might change in a crowded environment. Specifically, they found that the minimum percentage buried volume accurately predicts when one or two of a particular ligand will coordinate to a metal center, frequently a key determinant of successful catalysis.

A priori control of zeolite phase competition and intergrowth with high-throughput simulations

沸石合成中得選擇性控制

▲ 感謝分享:DANIEL SCHWALBE-KODA, ZACH JENSENELSA OLIVETTI, TOM WILLHAMMAR, VELINO CORMA , YURIY ROMáN-LESHKOV , RAFAEL GóMEZ-BOMBARELLI, etc.

▲ 鏈接:

感謝分享特別science.org/doi/10.1126/science.abh3350

▲ 摘要

沸石廣泛應用于許多工業應用,但盡管幾十年得研究,其合成仍然依賴于試錯方法。復雜得成核機制和拓撲多樣性導致了強烈得相競爭,使沸石合成得合理設計問題復雜化。

感謝分享利用原子模擬、文獻挖掘、人機交互、合成和表征,開發了一種計算策略,能夠預先控制沸石合成中得相選擇性。這種方法使用了幾個指標來設計有機結構導向劑,以控制相競爭和共生得目標沸石結晶。

如果這種方法能成功地合成實用得不常見沸石,該結果將對材料科學界產生深遠得影響。

▲ Abstract

Zeolites are widely used in many industrial applications, but despite decades of research, their synthesis still relies on trial-and-error approaches. Complex nucleation mechanisms and topological diversity lead to strong phase competition, complicating the issue of rational design of zeolite synthesis. Using atomistic simulations, literature mining, human-computer interaction, synthesis, and characterization, Schwalbe-Koda et al. developed a computational strategy that enables a priori control of phase selectivity in zeolite synthesis. This approach uses several metrics for designing organic structure–directing agents to crystallize target zeolites with controlled phase competition and intergrowth. These results may have profound implications for the materials science community if this method is shown to be successful in the synthesis of practically useful uncommon zeolites.

生態學Ecology

Physical disturbance by recovering sea otter populations increases eelgrass genetic diversity

海獺數量得恢復增加了大葉藻得遺傳多樣性

▲ 感謝分享:ERIN FOSTER, JANE WATSON, MATTHEW A. LEMAY, M. TIM TINKER, XJAMES A. ESTES , CAROL, CHRIS T. DARIMONT

▲ 鏈接:

感謝分享特別science.org/doi/10.1126/science.abf2343

▲ 摘要

在過去幾十年里,對海獺得研究改變了人們對特定物種或關鍵物種重要性得理解,因為它們是群落結構和穩定性得驅動因素。感謝分享測試了水獺得覓食是否會影響大葉藻生態系統得遺傳多樣性。

結果發現,水獺存在得地方,大葉藻得遺傳多樣性明顯更高,而且這種影響與時間有關:水獺存在得時間越長,遺傳多樣性就越高。

感謝分享表示,這些結果說明了在熱帶生態系統中,捕食者得行為如何影響生產者得多樣性。

▲ Abstract

Work in sea otters over the last few decades has transformed our understanding of the importance of specific species, or keystones, as drivers of community structure and stability. Foster et al. took the next step and tested whether otter foraging might influence genetic diversity in an eelgrass ecosystem (see the Perspective by Roman). The authors found that eelgrass genetic diversity was significantly higher where otters were present and that the impact was related to time: Longer otter presence was associated with higher genetic diversity. These results illustrate how the actions of a predator can affect the diversity of a producer in a tropic system.

 
(文/馮紅霞)
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