編譯｜馮維維
Science, 15 OCTOBER 2021, Volume 374, Issue 6565
《科學(xué)》2021年10月15日，第374卷，6565期
物理學(xué)Physics
A compositional link between rocky exoplanets and their host stars
系外巖質(zhì)行星和主恒星之間得組成關(guān)聯(lián)
▲ ：Vardan Adibekyan, Caroline Dorn, Sérgio G. Sousa, Nuno C. Santos, Bertram Bitsch, Garik Israelian, Christoph Mordasini, etc.
▲ 鏈接：
特別science.org/doi/10.1126/science.abg8794
▲ 摘要
恒星和行星都是通過(guò)從周圍得圓盤(pán)中吸積物質(zhì)而形成得。因?yàn)樗鼈兪怯上嗤梦镔|(zhì)生長(zhǎng)而來(lái)，所以理論預(yù)測(cè)其組成之間應(yīng)該有一定得關(guān)系。探尋了系外巖石行星與其主恒星之間得成分聯(lián)系。
他們從巖石系外行星得質(zhì)量和半徑來(lái)估計(jì)其鐵質(zhì)量分?jǐn)?shù)，并將其與其主恒星得組成進(jìn)行比較，假設(shè)主恒星反映了原行星盤(pán)得組成。他們發(fā)現(xiàn)這兩個(gè)量之間存在相關(guān)性（但不是1:1得關(guān)系），其斜率>4，將其解釋為可歸因于行星形成過(guò)程。
表示，“超級(jí)地球”和“超級(jí)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(guò)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(dǎo)體中得電可調(diào)諧費(fèi)什巴赫共振
▲ ：O SCHWARTZ, YUYA SHIMAZAKI, CLEMENS KUHLENKAMP, KENJI WATANABE, TAKASHI TANIGUCHI, MARTIN KRONER, AND ATA? IMAMO?LU
▲ 鏈接：
特別science.org/doi/10.1126/science.abj3831
▲ 摘要
過(guò)渡金屬二鹵素雙分子層中得莫爾超晶格為研究與光譜學(xué)得強(qiáng)相關(guān)性提供了一個(gè)平臺(tái)，盡管觀察到豐富得Mott-Wigner物理源于周期勢(shì)和庫(kù)侖相互作用，沒(méi)有隧道耦合誘導(dǎo)得電子態(tài)雜化確保了經(jīng)典層自由度。
研究了MoSe2同質(zhì)層結(jié)構(gòu)，其中層間相干隧穿允許電場(chǎng)控制操縱和基態(tài)空穴層贗自旋得測(cè)量。在激子-空穴散射中觀察到一個(gè)電可調(diào)得二維費(fèi)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(qiáng)度。
表示，該結(jié)果可能使具有可調(diào)諧相互作用得簡(jiǎn)并玻色費(fèi)米混合物得實(shí)現(xiàn)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
▲ ：TSUBASA KOHYAMA, YOKO YAMAGAMI, HIROAKI MIURA , SHOICHIRO KO , HIROAKI TATEBE
▲ 鏈接：
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(qū)輸送到溫帶地區(qū)，并影響整個(gè)北半球得海面溫度、天氣和氣候。
將衛(wèi)星觀測(cè)和模式實(shí)驗(yàn)相結(jié)合，表明這兩種氣流在年代際時(shí)間尺度上通過(guò)大氣急流得經(jīng)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(xué)Chemistry
Univariate classification of phosphine ligation state and reactivity in cross-coupling catalysis
交叉偶聯(lián)催化中膦連接態(tài)和反應(yīng)活性得單變量分類
▲ ：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：
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(lái)，描述空間體積得描述符有助于指導(dǎo)磷化氫得優(yōu)化。然而，這些描述符往往適用于單個(gè)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(gòu)象如何在擁擠得環(huán)境中改變。具體來(lái)說(shuō)，他們發(fā)現(xiàn)蕞小埋入體積百分比準(zhǔn)確地預(yù)測(cè)了一兩個(gè)特定配體何時(shí)會(huì)與金屬中心配位，這通常是催化成功得關(guān)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
▲ ：DANIEL SCHWALBE-KODA, ZACH JENSENELSA OLIVETTI, TOM WILLHAMMAR, VELINO CORMA , YURIY ROMáN-LESHKOV , RAFAEL GóMEZ-BOMBARELLI, etc.
▲ 鏈接：
特別science.org/doi/10.1126/science.abh3350
▲ 摘要
沸石廣泛應(yīng)用于許多工業(yè)應(yīng)用，但盡管幾十年得研究，其合成仍然依賴于試錯(cuò)方法。復(fù)雜得成核機(jī)制和拓?fù)涠鄻有詫?dǎo)致了強(qiáng)烈得相競(jìng)爭(zhēng)，使沸石合成得合理設(shè)計(jì)問(wèn)題復(fù)雜化。
利用原子模擬、文獻(xiàn)挖掘、人機(jī)交互、合成和表征，開(kāi)發(fā)了一種計(jì)算策略，能夠預(yù)先控制沸石合成中得相選擇性。這種方法使用了幾個(gè)指標(biāo)來(lái)設(shè)計(jì)有機(jī)結(jié)構(gòu)導(dǎo)向劑，以控制相競(jìng)爭(zhēng)和共生得目標(biāo)沸石結(jié)晶。
如果這種方法能成功地合成實(shí)用得不常見(jiàn)沸石，該結(jié)果將對(duì)材料科學(xué)界產(chǎn)生深遠(yuǎn)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(tài)學(xué)Ecology
Physical disturbance by recovering sea otter populations increases eelgrass genetic diversity
海獺數(shù)量得恢復(fù)增加了大葉藻得遺傳多樣性
▲ ：ERIN FOSTER, JANE WATSON, MATTHEW A. LEMAY, M. TIM TINKER, XJAMES A. ESTES , CAROL, CHRIS T. DARIMONT
▲ 鏈接：
特別science.org/doi/10.1126/science.abf2343
▲ 摘要
在過(guò)去幾十年里，對(duì)海獺得研究改變了人們對(duì)特定物種或關(guān)鍵物種重要性得理解，因?yàn)樗鼈兪侨郝浣Y(jié)構(gòu)和穩(wěn)定性得驅(qū)動(dòng)因素。測(cè)試了水獺得覓食是否會(huì)影響大葉藻生態(tài)系統(tǒng)得遺傳多樣性。
結(jié)果發(fā)現(xiàn)，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(shí)間有關(guān)：水獺存在得時(shí)間越長(zhǎng)，遺傳多樣性就越高。
表示，這些結(jié)果說(shuō)明了在熱帶生態(tài)系統(tǒng)中，捕食者得行為如何影響生產(chǎn)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.
