化学Chemistry Detection of interstellar 1-cyanopyrene: A four-ring polycyclic aromatic hydrocarbon 星际四环多环芳烃1 氰芘的检测 ▲ 作者：GABI WENZEL, ILSA R. COOKE, P. BRYAN CHANGALA, EDWIN A. BERGIN, SHUO ZHANG, ANDREW M. BURKHARDT, ALEX N. BYRNE, STEVEN B. CHARNLEY, MARTIN A. CORDINER, AND BRETT A. MCGUIRE ▲链接： https://www.science.org/doi/10.1126/science.adq6391 ▲摘要： 多环芳烃（PAHs）是含有相邻芳环的有机份子。红外发射波段注解，多环芳烃在太空中是丰硕的，但在星际介质中只检测到少数特定的多环芳烃。研究者操纵绿岸千里镜对致密星云TMC 1进行射电不雅测，发现了1 氰芘，一种四环多环芳烃芘相干的氰基代替衍生物。 他们测得的1 氰芘柱密度约为1.52 1012cm-2，由此估量芘在TMC-1中含有高达0.1%的碳。这类品貌注解星际多环芳烃化学有益在芘的发生。研究者认为，一些供给给年青行星系统的碳是由发源在冷份子云的多环芳烃携带的。 ▲ Abstract： Polycyclic aromatic hydrocarbons (PAHs) are organic molecules containing adjacent aromatic rings. Infrared emission bands show that PAHs are abundant in space, but only a few specific PAHs have been detected in the interstellar medium. We detected 1-cyanopyrene, a cyano-substituted derivative of the related four-ring PAH pyrene, in radio observations of the dense cloud TMC-1, using the Green Bank Telescope. The measured column density of 1-cyanopyrene is ~ 1.52 1012cm-2, from which we estimate that pyrene contains up to 0.1% of the carbon in TMC-1. This abundance indicates that interstellar PAH chemistry favors the production of pyrene. We suggest that some of the carbon supplied to young planetary systems is carried by PAHs that originate in cold molecular clouds. Synchronous recognition of amines in oxidative carbonylation toward unsymmetrical ureas 不合错误称尿素氧化羰基化进程中胺的同步辨认 ▲ 作者：JINHUI WANG, SHENGCHUN WANG, ZHIHONG WEI, PENGJIE WANG, YANWEI CAO, YANG HUANG, LIN HE, AND AIWEN LEI ▲链接： https://www.science.org/doi/10.1126/science.adl0149 ▲摘要： 不合错误称尿平素见在药品和生物活性化合物中。但是，设计谋略来选择性地引入两种分歧的胺来构建不合错误称脲依然是一个挑战。研究者利用同步辨认策略，操纵自由基和亲核活化来辨别仲胺和伯胺。 具体而言，铜催化剂优先将仲胺氧化为自由基，而钴催化剂将伯胺羰基化以发生钴酰胺。这些片断经由过程协同催化偶联发生具有高选择性的不合错误称脲，41种生物活性化合物和6种药物的润色证实了这一点。 ▲ Abstract： Unsymmetrical ureas are commonly found in pharmaceuticals and bioactive compounds. However, devising strategies to introduce two distinct amines selectively in the construction of unsymmetrical ureas remains a challenge. In this work, we use a synchronous recognition strategy that takes advantage of radical and nucleophilic activation to discriminate between secondary and primary amines. Specifically, a copper catalyst preferentially oxidizes secondary amines to radical species, whereas a cobalt catalyst carbonylates primary amines to produce cobalt amides. Coupling these fragments by cooperative catalysis produces unsymmetrical ureas with high selectivity, as showcased by the modification of 41 biologically active compounds and six drugs. 物理学Physics Subambient daytime radiative cooling of vertical surfaces 垂直概况的白日辐射冷却 ▲ 作者：FEI XIE, WEILIANG JIN, J. RYAN NOLEN, HAO PAN, NAIQIN YI, YANG AN, ZHIYU ZHANG, XIANGTONG KONG, FEI ZHU, AND WEI LI ▲链接： https://www.science.org/doi/10.1126/science.adn2524 ▲摘要： 白日亚情况辐射冷却经由过程向外层空间发射热辐射，使温度被动地低在情况温度，即便在阳光直射下也是如斯。这项手艺有很多使人兴奋的利用前景。但是，之前的亚情况日间辐射冷却的演示需要直接面向天空的概况，而这些不克不及利用在在实际场景中无处不在的垂直概况，如建筑物和车辆。 研究者利用分层设计，角度不合错误称，光谱选择性热发射器演示了峰值阳光下垂直概况的亚情况日间辐射冷却。在每平方米约920瓦的峰值阳光下，他们的发射器到达的温度比情况温度低约2.5 C，与硅聚合物夹杂辐射冷却器和商用白漆比拟，温度别离下降了约4.3 C和8.9 C。 ▲ Abstract： Subambient daytime radiative cooling enables temperatures to passively reach below ambient temperature, even under direct sunlight, by emitting thermal radiation toward outer space. This technology holds promise for numerous exciting applications. However, previous demonstrations of subambient daytime radiative cooling require surfaces that directly face the sky, and these cannot be applied to vertical surfaces that are ubiquitous in real-world scenarios such as buildings and vehicles. Here, we demonstrate subambient daytime radiative cooling of vertical surfaces under peak sunlight using a hierarchically designed, angularly asymmetric, spectrally selective thermal emitter. Under peak sunlight of about 920 watts per square meter, our emitter reaches a temperature that is about 2.5 C below ambient temperature, corresponding to a temperature reduction of about 4.3 and 8.9 C compared with a silica-polymer hybrid radiative cooler and commercial white paint, respectively. Glaciation of liquid clouds, snowfall, and reduced cloud cover at industrial aerosol hot spots 工业气溶胶热门的冷凝感化 ▲ 作者：VELLE TOLL, JORMA RAHU, HANNES KEERNIK, HEIDO TROFIMOV, TANEL VOORMANSIK, PETER MANSHAUSEN, EMMA HUNG, DANIEL MICHELSON, MATTHEW W. CHRISTENSEN, AND NICOLAS BELLOUIN ▲链接： https://www.science.org/doi/10.1126/science.adl0303 ▲摘要： 报酬气溶胶冻结过冷云滴的能力依然存在争议。研究者供给了温度在 10 C和 24 C之间的工业气溶胶热门的过冷液态水云结冰的不雅测证据。与四周液态水云比拟，受冰川影响区域的短波反射率下降了14%，长波辐射增添了4%。云量削减了8%，云光学厚度削减了18%。另外，天天由冰川引发的降雪量到达15毫米。 工业气溶胶热门顺风标的目的的冰期事务注解，报酬气溶胶可能起到冰核粒子的感化。但是，核电站顺风处罕有的冰川事务注解，除气溶胶排放外，其他身分也可能在不雅测到的冰川事务中起感化。 ▲ Abstract： The ability of anthropogenic aerosols to freeze supercooled cloud droplets remains debated. In this work, we present observational evidence for the glaciation of supercooled liquid-water clouds at industrial aerosol hot spots at temperatures between -10 and -24 C. Compared with the nearby liquid-water clouds, shortwave reflectance was reduced by 14% and longwave radiance was increased by 4% in the glaciation-affected regions. There was an 8% reduction in cloud cover and an 18% reduction in cloud optical thickness. Additionally, daily glaciation-induced snowfall accumulations reached 15 millimeters. Glaciation events downwind of industrial aerosol hot spots indicate that anthropogenic aerosols likely serve as ice-nucleating particles. However, rare glaciation events downwind of nuclear power plants indicate that factors other than aerosol emissions may also play a role in the observed glaciation events. 生态学与地质学Ecology Geology Diverse and larger tree islands promote native tree diversity in oil palm landscapes 多样化的更年夜的树岛增进了油棕景不雅华夏生树木的多样性 ▲ 作者：GUSTAVO B. PATERNO , FABIAN BRAMBACH, NATHALY GUERRERO-RAM REZ, DELPHINE CLARA ZEMP, AIZA F. CANTILLO, NICOL CAMARRETTA, CARINA C. M. MOURA, OLIVER GAILING, JOHANNES BALLAUFF, AND HOLGER KREFT ▲链接： https://www.science.org/doi/10.1126/science.ado1629 ▲摘要： 在单一栽培为主的景不雅中，恢复活物多样性是一个优先事项，但有用的恢复策略还没有肯定。本研究对油棕景不雅中52小我工岛木本植物的分类、系统发育和功能多样性进行了被动恢复策略和自动恢复策略的对照研究。年夜的树岛和较高的初始植物多样性增进了多样性的恢复，特别是景不雅程度上的功能多样性。 在局部标准上，研究成果注解，更年夜的初始莳植多样性会带来更年夜的当地招募多样性，从而降服了高度润色景不雅中天然招募的局限性。成立年夜型和多样化的树岛对庇护油棕景不雅中的珍稀、特有和丛林相干物种相当主要。 ▲ Abstract： In monoculture-dominated landscapes, recovering biodiversity is a priority, but effective restoration strategies have yet to be identified. In this study, we experimentally tested passive and active restoration strategies to recover taxonomic, phylogenetic, and functional diversity of woody plants within 52 tree islands established in an oil palm landscape. Large tree islands and higher initial planted diversity catalyzed diversity recovery, particularly functional diversity at the landscape level. At the local scale, results demonstrated that greater initial planting diversity begets greater diversity of native recruits, overcoming limitations of natural recruitment in highly modified landscapes. Establishing large and diverse tree islands is crucial for safeguarding rare, endemic, and forest-associated species in oil palm landscapes. Predictions of groundwater PFAS occurrence at drinking water supply depths in the United States 美国饮用水供给深度地下水中的PFAS猜测 ▲ 作者：ANDREA K. TOKRANOV, KATHERINE M. RANSOM, LAURA M. BEXFIELD, BRUCE D. LINDSEY, ELISE WATSON, DANIELLE I. DUPUY, PAUL E. STACKELBERG, MIRANDA S. FRAM, STEFAN A. VOSS, AND PAUL M. BRADLEY ▲链接： https://www.science.org/doi/10.1126/science.ado6638 ▲摘要： 全氟烷基和多氟烷基物资（PFAS）俗称 永久的化学品 ，对人类健康有晦气影响，因为持久和普遍利用，已污染了美国各地的饮用水供给。因为缺少系统的阐发，美国人可能在不知不觉中饮用了含有PFAS的水，特殊是在家庭供水中。 研究者提出了一个极端梯度加强模子，用在猜测美国临近地域饮用水供给深处地下水中PFAS的产生。模子成果注解，在美国临近地域，7100万至9500万人在进行任何处置之前，可能依靠在PFAS浓度可检测的地下水作为饮用水供给。 ▲ Abstract： Per- and polyfluoroalkyl substances (PFAS), known colloquially as forever chemicals, have been associated with adverse human health effects and have contaminated drinking water supplies across the United States owing to their long-term and widespread use. People in the United States may unknowingly be drinking water that contains PFAS because of a lack of systematic analysis, particularly in domestic water supplies. We present an extreme gradient boosting model for predicting the occurrence of PFAS in groundwater at the depths of drinking water supply for the conterminous United States. Our model results indicate that 71 million to 95 million people in the conterminous United States potentially rely on groundwater with detectable concentrations of PFAS for their drinking water supplies before any treatment.特殊声明：本文转载仅仅是出在传布信息的需要，其实不意味着代表本网站不雅点或证实其内容的真实性；如其他媒体、网站或小我从本网站转载利用，须保存本网站注明的“来历”，并自大版权等法令责任；作者假如不但愿被转载或联系转载稿费等事宜，请与我们联系。
