敬請關注譯 | 未玖
Science, 10 MAY 2024, VOL 384, ISSUE 6696
《最新科學》2024年5月10日，第384卷，6696期
天文學Astronomy
Isotopic evidence of long-lived volcanism on Io
木衛一長期火山活動得同位素證據
▲ ：KATHERINE DE KLEER, ERY C. HUGHES, FRANCIS NIMMO, JOHN EILER, AMY E. HOFMANN, STATIA LUSZCZ-COOK, ET AL.
▲ 鏈接：
https://特別science.org/doi/10.1126/science.adj0625
▲ 摘要：
木衛一上有大量得火山活動，由潮汐加熱驅動。木衛一揮發性化學元素（包括硫和氯）得同位素組成反映了其放氣和質量損失得歷史，從而記錄了演化信息。
研究組利用對木衛一大氣層得亞毫米觀測來測量氣態二氧化硫和一氧化硫中得硫同位素，以及氣態氯化鈉和氯化鉀中得氯同位素。
結果發現34S/32S = 0.0595±0.0038（相當于δ34S = +347±86‰），與太陽系得平均值相比高度富集，這表明木衛一已經損失了94~99%得可用硫。測量還發現37Cl/35Cl = 0.403±0.028（δ37Cl = +263±88‰），表明氯也同樣富集。
這些結果表明，木衛一在其大部分（或全部）歷史中都有火山活動，早期專家有更高得放氣率和質量損失率。
▲ Abstract：
Jupiter’s moon Io hosts extensive volcanism, driven by tidal heating. The isotopic composition of Io’s inventory of volatile chemical elements, including sulfur and chlorine, reflects its outgassing and mass-loss history and thus records information about its evolution. We used submillimeter observations of Io’s atmosphere to measure sulfur isotopes in gaseous sulfur dioxide and sulfur monoxide, and chlorine isotopes in gaseous sodium chloride and potassium chloride. We find 34S/32S = 0.0595 ± 0.0038 (equivalent to δ34S = +347 ± 86‰), which is highly enriched compared to average Solar System values and indicates that Io has lost 94 to 99% of its available sulfur. Our measurement of 37Cl/35Cl = 0.403 ± 0.028 (δ37Cl = +263 ± 88‰) shows that chlorine is similarly enriched. These results indicate that Io has been volcanically active for most (or all) of its history, with potentially higher outgassing and mass-loss rates at earlier times.
材料最新科學Materials Science
Catalog of topological phonon materials
拓撲聲子材料目錄
▲ ：YUANFENG XU, M. G. VERGNIORY, DA-SHUAI MA, JUAN L. MA?ES, ZHI-DA SONG, B. ANDREI BERNEVIG, ET AL.
▲ 鏈接：
https://特別science.org/doi/10.1126/science.adf8458
▲ 摘要：
聲子在固態系統得許多特性中起著至關重要得作用，人們期望拓撲聲子可導致豐富和非常規得物理特性。
在現有聲子材料數據庫得基礎上，研究組匯敬請關注了1萬多種三維晶體材料得拓撲聲子帶目錄。利用拓撲量子化學計算了聲子數據庫中材料得每組孤立聲子帶得能帶表示、兼容關系和能帶拓撲。
此外還計算了所有拓撲平凡帶得實空間不變量，并將其分類為原子能帶或受阻原子能帶。研究組已選擇了1000多種“理想”得非平凡聲子材料用于未來實驗分析。這些數據集將被用于建立拓撲聲子數據庫。
▲ Abstract：
Phonons play a crucial role in many properties of solid-state systems, and it is expected that topological phonons may lead to rich and unconventional physics. On the basis of the existing phonon materials databases, we have compiled a catalog of topological phonon bands for more than 10,000 three-dimensional crystalline materials. Using topological quantum chemistry, we calculated the band representations, compatibility relations, and band topologies of each isolated set of phonon bands for the materials in the phonon databases. Additionally, we calculated the real-space invariants for all the topologically trivial bands and classified them as atomic or obstructed atomic bands. We have selected more than 1000 “ideal” nontrivial phonon materials to motivate future experiments. The datasets were used to build the Topological Phonon Database.
The odd-number cyclo[13]carbon and its dimer, cyclo[26]carbon
奇數環[13]碳及其二聚體環[26]碳
▲ ：FLORIAN ALBRECHT, IGOR RON?EVI?, YUEZE GAO, FABIAN PASCHKE, ALBERTO BAIARDI, IVANO TAVERNELLI, ET AL.
▲ 鏈接：
https://特別science.org/doi/10.1126/science.ado1399
▲ 摘要：
N個碳原子得分子環（環[N]碳，或CN）是測試量子化學理論方法得優秀基準系統，也是其他富碳材料有價值得前體。奇數—N環碳迄今為止一直難以捉摸，預計比偶數—N環碳更不穩定。
研究組報道了用掃描探針顯微鏡尖端操縱十氯芴在表面合成環[13]碳，C13。通過實驗和理論模擬表征了C13得性質。C13采用三重態基態和扭結幾何結構得開殼構型，根據分子環境得不同表現出不同程度得扭曲和卡賓局域化。
此外，研究組制備并表征了C13二聚體，即環[26]碳，證明了環碳及其前體作為碳同素異形體構建塊得潛力。
▲ Abstract：
Molecular rings of N carbon atoms (cyclo[N]carbons, or CN) are excellent benchmarking systems for testing quantum chemical theoretical methods and valuable precursors to other carbon-rich materials. Odd-N cyclocarbons, which have been elusive to date, are predicted to be even less stable than even-N cyclocarbons. We report the on-surface synthesis of cyclo[13]carbon, C13, by manipulation of decachlorofluorene with a scanning probe microscope tip. We elucidated the properties of C13 by experiment and theoretical modeling. C13 adopts an open-shell configuration with a triplet ground state and a kinked geometry, which shows different extents of distortion and carbene localization depending on the molecular environment. Moreover, we prepared and characterized the C13 dimer, cyclo[26]carbon, demonstrating the potential of cyclocarbons and their precursors as building blocks for carbon allotropes.
化學Chemistry
Atomically dispersed hexavalent iridium oxide from MnO2 reduction for oxygen evolution catalysis
MnO2還原得原子分散六價氧化銥助力析氧催化
▲ ：AILONG LI, SHUANG KONG, KIYOHIRO ADACHI, HESHI OOKA, KAZUNA FUSHIMI, QIKE JIANG, ET AL.
▲ 鏈接：
https://特別science.org/doi/10.1126/science.adg5193
▲ 摘要：
人們預測六價氧化銥（IrVI）在酸中得析氧反應中比其他氧化銥更具活性、更穩定；然而其實驗實現仍頗具挑戰性。
研究組報道了用于質子交換膜（PEM）水電解得原子分散IrVI氧化物（IrVI-ado）得合成、表征和應用。用氧化錳（MnO2）氧化取代六氯銥酸鉀（K2IrCl6）配體，合成了IrVI-ado。
IrVI-ado得質量比活度（1.7×105 A/gIr）和周轉率（1.5×108）超過了基準銥氧化物，PEM操作期間得原位X射線分析表明，IrVI在電流密度高達2.3 A/cm2時仍具備耐久性。IrVI-ado得高活性和穩定性顯示了其作為PEM電解陽極材料得前景。
▲ Abstract：
Hexavalent iridium (IrVI) oxide is predicted to be more active and stable than any other iridium oxide for the oxygen evolution reaction in acid; however, its experimental realization remains challenging. In this work, we report the synthesis, characterization, and application of atomically dispersed IrVI oxide (IrVI-ado) for proton exchange membrane (PEM) water electrolysis. The IrVI-ado was synthesized by oxidatively substituting the ligands of potassium hexachloroiridate(IV) (K2IrCl6) with manganese oxide (MnO2). The mass-specific activity (1.7 × 105 amperes per gram of iridium) and turnover number (1.5 × 108) exceeded those of benchmark iridium oxides, and in situ x-ray analysis during PEM operations manifested the durability of IrVI at current densities up to 2.3 amperes per square centimeter. The high activity and stability of IrVI-ado showcase its promise as an anode material for PEM electrolysis.
Scalable decarboxylative trifluoromethylation by ion-shielding heterogeneous photoelectrocatalysis
離子屏蔽非均相光電催化助力可擴展脫羧三氟甲基化
▲ ：YIXIN CHEN, YUCHEN HE, YONG GAO, JIAKUN XUE, WEI QU, JUN XUAN AND YIMING MO
▲ 鏈接：
https://特別science.org/doi/10.1126/science.adm8902
▲ 摘要：
電化學為增值精細化學品提供了可持續得合成途徑，但通常受到電極和不同于靶位點得氧化還原敏感功能性之間競爭電子轉移得限制。
研究組描述了一種離子屏蔽得非均相光電催化策略，以施加傳質限制，從而逆轉了熱力學決定得電子轉移順序。使用三氟乙酸鹽（一種廉價但相對惰性得三氟甲基（CF3）源）展示了該策略可實現敏感（雜）芳烴得脫羧三氟甲基化。
由三氟乙酸根陰離子靜電吸附在正鉬摻雜得三氧化鎢（WO3）光陽極上形成得離子屏蔽層，可防止基底和光生空穴之間無益得電子轉移。通過利用光電化學流動電池實現穩健得光陽極穩定性（約380小時）、良好得基底范圍，以及100克合成得可擴展能力，充分證明了該策略得實用性。
▲ Abstract：
Electrochemistry offers a sustainable synthesis route to value-added fine chemicals but is often constrained by competing electron transfer between the electrode and redox-sensitive functionalities distinct from the target site. Here, we describe an ion-shielding heterogeneous photoelectrocatalysis strategy to impose mass-transfer limitations that invert the thermodynamically determined order of electron transfer. This strategy is showcased to enable decarboxylative trifluoromethylation of sensitive (hetero)arenes by using trifluoroacetate, an inexpensive yet relatively inert trifluoromethyl group (CF3) source. An ion-shielding layer, formed by trifluoroacetate anions electrostatically adsorbed on a positive molybdenum-doped tungsten trioxide (WO3) photoanode, prevents undesired electron transfer between substrates and photogenerated holes. The practicality of the developed method was demonstrated with robust photoanode stability (approximately 380 hours), a good substrate scope, and scaling capability to achieve 100-gram synthesis by using photoelectrochemical flow cells.
地球最新科學Earth Science
A diminished North Atlantic nutrient stream during Younger Dryas climate reversal
新仙女木期氣候逆轉期間北大西洋營養流減少
▲ ：JEAN LYNCH-STIEGLITZ, TYLER D. VOLLMER, SHANNON G. VALLEY, ERIC BLACKMON, SIFAN GU AND THOMAS M. MARCHITTO
▲ 鏈接：
https://特別science.org/doi/10.1126/science.adi5543
▲ 摘要：
北大西洋得高生物生產力由通過墨西哥灣流（營養流）向該地區平流供應得營養物質所刺激。有人提出，預計未來大西洋經向翻轉環流（AMOC）得下降將導致營養物質供應減少，從而導致生產力下降。
研究組分析了標志著從末次冰期過渡得新仙女木期氣候逆轉期間營養流是如何變化得。在AMOC減弱期間，佛羅里達海峽得墨西哥灣流營養物質含量下降，氧含量增加。營養流得減少伴隨著北大西洋高緯度地區生物生產力得下降，這圖片了理論和建模研究中所假設得聯系。
▲ Abstract：
The high rate of biological productivity in the North Atlantic is stimulated by the advective supply of nutrients into the region via the Gulf Stream (nutrient stream). It has been proposed that the projected future decline in the Atlantic Meridional Overturning Circulation (AMOC) will cause a reduction in nutrient supply and resulting productivity. In this work, we examine how the nutrient stream changed over the Younger Dryas climate reversal that marked the transition out of the last ice age. Gulf Stream nutrient content decreased, and oxygen content increased at the Florida Straits during this time of weakened AMOC. The decreased nutrient stream was accompanied by a reduction in biological productivity at higher latitudes in the North Atlantic, which supports the link postulated in theoretical and modeling studies.
