编译|未玖Science,10MAY2024,VOL384,ISSUE6696《科学》2024年5月10日，第384卷，6696期天文学AstronomyIsotopicevidenceoflong-livedvolcanismonIo木卫一长期火山活动的同位素证据▲作者：KATHERINEDEKLEER,ERYC.HUGHES,FRANCISNIMMO,JOHNEILER,AMYE.HOFMANN,STATIALUSZCZ-COOK,ETAL.▲链接：https://www.science.org/doi/10.1126/science.adj0625▲摘要：木卫一上有大量的火山活动，由潮汐加热驱动。木卫一挥发性化学元素（包括硫和氯）的同位素组成反映了其放气和质量损失的历史，从而记录了演化信息。研究组利用对木卫一大气层的亚毫米观测来测量气态二氧化硫和一氧化硫中的硫同位素，以及气态氯化钠和氯化钾中的氯同位素。结果发现34S/32S=0.0595±0.0038（相当于δ34S=+347±86‰），与太阳系的平均值相比高度富集，这表明木卫一已经损失了94~99%的可用硫。测量还发现37Cl/35Cl=0.403±0.028（δ37Cl=+263±88‰），表明氯也同样富集。这些结果表明，木卫一在其大部分（或全部）历史中都有火山活动，早期可能有更高的放气率和质量损失率。▲Abstract：Jupiter’smoonIohostsextensivevolcanism,drivenbytidalheating.TheisotopiccompositionofIo’sinventoryofvolatilechemicalelements,includingsulfurandchlorine,reflectsitsoutgassingandmass-losshistoryandthusrecordsinformationaboutitsevolution.WeusedsubmillimeterobservationsofIo’satmospheretomeasuresulfurisotopesingaseoussulfurdioxideandsulfurmonoxide,andchlorineisotopesingaseoussodiumchlorideandpotassiumchloride.Wefind34S/32S=0.0595±0.0038(equivalenttoδ34S=+347±86‰),whichishighlyenrichedcomparedtoaverageSolarSystemvaluesandindicatesthatIohaslost94to99%ofitsavailablesulfur.Ourmeasurementof37Cl/35Cl=0.403±0.028(δ37Cl=+263±88‰)showsthatchlorineissimilarlyenriched.TheseresultsindicatethatIohasbeenvolcanicallyactiveformost(orall)ofitshistory,withpotentiallyhigheroutgassingandmass-lossratesatearliertimes.材料科学MaterialsScienceCatalogoftopologicalphononmaterials拓扑声子材料目录▲作者：YUANFENGXU,M.G.VERGNIORY,DA-SHUAIMA,JUANL.MA?ES,ZHI-DASONG,B.ANDREIBERNEVIG,ETAL.▲链接：https://www.science.org/doi/10.1126/science.adf8458▲摘要：声子在固态系统的许多特性中起着至关重要的作用，人们期望拓扑声子可导致丰富和非常规的物理特性。在现有声子材料数据库的基础上，研究组汇编了1万多种三维晶体材料的拓扑声子带目录。利用拓扑量子化学计算了声子数据库中材料的每组孤立声子带的能带表示、兼容关系和能带拓扑。此外还计算了所有拓扑平凡带的实空间不变量，并将其分类为原子能带或受阻原子能带。研究组已选择了1000多种“理想”的非平凡声子材料用于未来实验分析。这些数据集将被用于建立拓扑声子数据库。▲Abstract：Phononsplayacrucialroleinmanypropertiesofsolid-statesystems,anditisexpectedthattopologicalphononsmayleadtorichandunconventionalphysics.Onthebasisoftheexistingphononmaterialsdatabases,wehavecompiledacatalogoftopologicalphononbandsformorethan10,000three-dimensionalcrystallinematerials.Usingtopologicalquantumchemistry,wecalculatedthebandrepresentations,compatibilityrelations,andbandtopologiesofeachisolatedsetofphononbandsforthematerialsinthephonondatabases.Additionally,wecalculatedthereal-spaceinvariantsforallthetopologicallytrivialbandsandclassifiedthemasatomicorobstructedatomicbands.Wehaveselectedmorethan1000“ideal”nontrivialphononmaterialstomotivatefutureexperiments.ThedatasetswereusedtobuildtheTopologicalPhononDatabase.Theodd-numbercyclo[13]carbonanditsdimer,cyclo[26]carbon奇数环[13]碳及其二聚体环[26]碳▲作者：FLORIANALBRECHT,IGORRON?EVI?,YUEZEGAO,FABIANPASCHKE,ALBERTOBAIARDI,IVANOTAVERNELLI,ETAL.▲链接：https://www.science.org/doi/10.1126/science.ado1399▲摘要：N个碳原子的分子环（环[N]碳，或CN）是测试量子化学理论方法的优秀基准系统，也是其他富碳材料有价值的前体。奇数—N环碳迄今为止一直难以捉摸，预计比偶数—N环碳更不稳定。研究组报道了用扫描探针显微镜尖端操纵十氯芴在表面合成环[13]碳，C13。通过实验和理论模拟表征了C13的性质。C13采用三重态基态和扭结几何结构的开壳构型，根据分子环境的不同表现出不同程度的扭曲和卡宾局域化。此外，研究组制备并表征了C13二聚体，即环[26]碳，证明了环碳及其前体作为碳同素异形体构建块的潜力。▲Abstract：MolecularringsofNcarbonatoms(cyclo[N]carbons,orCN)areexcellentbenchmarkingsystemsfortestingquantumchemicaltheoreticalmethodsandvaluableprecursorstoothercarbon-richmaterials.Odd-Ncyclocarbons,whichhavebeenelusivetodate,arepredictedtobeevenlessstablethaneven-Ncyclocarbons.Wereporttheon-surfacesynthesisofcyclo[13]carbon,C13,bymanipulationofdecachlorofluorenewithascanningprobemicroscopetip.WeelucidatedthepropertiesofC13byexperimentandtheoreticalmodeling.C13adoptsanopen-shellconfigurationwithatripletgroundstateandakinkedgeometry,whichshowsdifferentextentsofdistortionandcarbenelocalizationdependingonthemolecularenvironment.Moreover,wepreparedandcharacterizedtheC13dimer,cyclo[26]carbon,demonstratingthepotentialofcyclocarbonsandtheirprecursorsasbuildingblocksforcarbonallotropes.化学ChemistryAtomicallydispersedhexavalentiridiumoxidefromMnO2reductionforoxygenevolutioncatalysisMnO2还原的原子分散六价氧化铱助力析氧催化▲作者：AILONGLI,SHUANGKONG,KIYOHIROADACHI,HIDESHIOOKA,KAZUNAFUSHIMI,QIKEJIANG,ETAL.▲链接：https://www.science.org/doi/10.1126/science.adg5193▲摘要：人们预测六价氧化铱（IrVI）在酸中的析氧反应中比其他氧化铱更具活性、更稳定；然而其实验实现仍颇具挑战性。研究组报道了用于质子交换膜（PEM）水电解的原子分散IrVI氧化物（IrVI-ado）的合成、表征和应用。用氧化锰（MnO2）氧化取代六氯铱酸钾（K2IrCl6）配体，合成了IrVI-ado。IrVI-ado的质量比活度（1.7×105A/gIr）和周转率（1.5×108）超过了基准铱氧化物，PEM操作期间的原位X射线分析表明，IrVI在电流密度高达2.3A/cm2时仍具备耐久性。IrVI-ado的高活性和稳定性显示了其作为PEM电解阳极材料的前景。▲Abstract：Hexavalentiridium(IrVI)oxideispredictedtobemoreactiveandstablethananyotheriridiumoxidefortheoxygenevolutionreactioninacid;however,itsexperimentalrealizationremainschallenging.Inthiswork,wereportthesynthesis,characterization,andapplicationofatomicallydispersedIrVIoxide(IrVI-ado)forprotonexchangemembrane(PEM)waterelectrolysis.TheIrVI-adowassynthesizedbyoxidativelysubstitutingtheligandsofpotassiumhexachloroiridate(IV)(K2IrCl6)withmanganeseoxide(MnO2).Themass-specificactivity(1.7×105amperespergramofiridium)andturnovernumber(1.5×108)exceededthoseofbenchmarkiridiumoxides,andinsitux-rayanalysisduringPEMoperationsmanifestedthedurabilityofIrVIatcurrentdensitiesupto2.3amperespersquarecentimeter.ThehighactivityandstabilityofIrVI-adoshowcaseitspromiseasananodematerialforPEMelectrolysis.Scalabledecarboxylativetrifluoromethylationbyion-shieldingheterogeneousphotoelectrocatalysis离子屏蔽非均相光电催化助力可扩展脱羧三氟甲基化▲作者：YIXINCHEN,YUCHENHE,YONGGAO,JIAKUNXUE,WEIQU,JUNXUANANDYIMINGMO▲链接：https://www.science.org/doi/10.1126/science.adm8902▲摘要：电化学为增值精细化学品提供了可持续的合成途径，但通常受到电极和不同于靶位点的氧化还原敏感功能性之间竞争电子转移的限制。研究组描述了一种离子屏蔽的非均相光电催化策略，以施加传质限制，从而逆转了热力学决定的电子转移顺序。使用三氟乙酸盐（一种廉价但相对惰性的三氟甲基（CF3）源）展示了该策略可实现敏感（杂）芳烃的脱羧三氟甲基化。由三氟乙酸根阴离子静电吸附在正钼掺杂的三氧化钨（WO3）光阳极上形成的离子屏蔽层，可防止基底和光生空穴之间无益的电子转移。通过利用光电化学流动电池实现稳健的光阳极稳定性（约380小时）、良好的基底范围，以及100克合成的可扩展能力，充分证明了该策略的实用性。▲Abstract：Electrochemistryoffersasustainablesynthesisroutetovalue-addedfinechemicalsbutisoftenconstrainedbycompetingelectrontransferbetweentheelectrodeandredox-sensitivefunctionalitiesdistinctfromthetargetsite.Here,wedescribeanion-shieldingheterogeneousphotoelectrocatalysisstrategytoimposemass-transferlimitationsthatinvertthethermodynamicallydeterminedorderofelectrontransfer.Thisstrategyisshowcasedtoenabledecarboxylativetrifluoromethylationofsensitive(hetero)arenesbyusingtrifluoroacetate,aninexpensiveyetrelativelyinerttrifluoromethylgroup(CF3)source.Anion-shieldinglayer,formedbytrifluoroacetateanionselectrostaticallyadsorbedonapositivemolybdenum-dopedtungstentrioxide(WO3)photoanode,preventsundesiredelectrontransferbetweensubstratesandphotogeneratedholes.Thepracticalityofthedevelopedmethodwasdemonstratedwithrobustphotoanodestability(approximately380hours),agoodsubstratescope,andscalingcapabilitytoachieve100-gramsynthesisbyusingphotoelectrochemicalflowcells.地球科学EarthScienceAdiminishedNorthAtlanticnutrientstreamduringYoungerDryasclimatereversal新仙女木期气候逆转期间北大西洋营养流减少▲作者：JEANLYNCH-STIEGLITZ,TYLERD.VOLLMER,SHANNONG.VALLEY,ERICBLACKMON,SIFANGUANDTHOMASM.MARCHITTO▲链接：https://www.science.org/doi/10.1126/science.adi5543▲摘要：北大西洋的高生物生产力由通过墨西哥湾流（营养流）向该地区平流供应的营养物质所刺激。有人提出，预计未来大西洋经向翻转环流（AMOC）的下降将导致营养物质供应减少，从而导致生产力下降。研究组分析了标志着从末次冰期过渡的新仙女木期气候逆转期间营养流是如何变化的。在AMOC减弱期间，佛罗里达海峡的墨西哥湾流营养物质含量下降，氧含量增加。营养流的减少伴随着北大西洋高纬度地区生物生产力的下降，这支持了理论和建模研究中所假设的联系。▲Abstract：ThehighrateofbiologicalproductivityintheNorthAtlanticisstimulatedbytheadvectivesupplyofnutrientsintotheregionviatheGulfStream(nutrientstream).IthasbeenproposedthattheprojectedfuturedeclineintheAtlanticMeridionalOverturningCirculation(AMOC)willcauseareductioninnutrientsupplyandresultingproductivity.Inthiswork,weexaminehowthenutrientstreamchangedovertheYoungerDryasclimatereversalthatmarkedthetransitionoutofthelasticeage.GulfStreamnutrientcontentdecreased,andoxygencontentincreasedattheFloridaStraitsduringthistimeofweakenedAMOC.ThedecreasednutrientstreamwasaccompaniedbyareductioninbiologicalproductivityathigherlatitudesintheNorthAtlantic,whichsupportsthelinkpostulatedintheoreticalandmodelingstudies.澳门新葡萄新京6663·「中国」官方网站-2024App 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