mutuali**（Exploring the Benefits of Mutuali**）

编译｜冯维维










Science, 23 OCTOBER 2020, VOL 370 ISSUE 6515



《科学》2020年10月23日，第370卷6515期














化学Chemistry






Polyethylene upcycling to long-chain alkylaromatics by tandem hydrogenolysis/aromatization



聚乙烯的新未来



▲ 作者：Fan Zhang, Manhao Zeng, Ryan D. Yappert, Jiakai Sun, Yu-Hsuan Lee, Anne M. LaPointe, Baron Peters, Mahdi M. Abu-Omar, Susannah L. Scott



▲ 链接：







▲ 摘要



目前，大多数塑料回收都是将垃圾切碎，用不像最初那样严格的工程要求的材料进行再利用。原则上，分子水平上的化学分解可以产生更高价值的产品。



然而，聚乙烯（最常见的塑料）中的碳碳键在没有高压氢气的情况下倾向于**这种方法。



作者报告称，一种铂/氧化铝催化剂可以将废聚乙烯直接转化为用于洗涤剂制造的原料长链烷基苯，而不需要外部氢气。



▲ Abstract



Most current plastic recycling involves chopping up the waste and repurposing it in materials with less stringent engineering requirements than the original application. Chemical decomposition at the molecular level could, in principle, lead to higher-value products. However, the carbon-carbon bonds in polyethylene, the most common plastic, tend to resist such approaches without exposure to high-pressure hydrogen. F. Zhang et al. now report that a platinum/alumina catalyst can transform waste polyethylene directly into long-chain alkylbenzenes, a feedstock for detergent manufacture, with no need for external hydrogen.










Design of higher valency in covalent organic frameworks



共价有机骨架的高价键设计



▲ 作者：Cornelius Gropp, Tianqiong Ma, Nikita Hanikel, Omar M. Yaghi



▲ 链接：







▲ 摘要



金属有机骨架（MOFs）比共价有机骨架（COFs）表现出更广泛的连通性和拓扑多样性，这主要是因为MOFs连接子可以连接3 ~24个离散单元，甚至一维棒材的无限个单元。



对于COFs，连接剂的价通常为3或4，反映有机碳的价。作者从1,4-硼苯基膦酸中创建了类似古巴的连接物，这些连接物可以凝聚成价为8的共价键，或者，通过添加酸，可以形成具有无限棒拓扑结构的大单晶。



▲ Abstract



Metal-organic frameworks (MOFs) have exhibited more extensive connectivity (valency) and topological diversity than covalent organic frameworks (COFs), mainly because MOF linkers can connect from 3 to 24 discrete units or even infinity for one-dimensional rods. For COFs, linkers generally have a valency of 3 or 4 that reflect the valency of organic carbon. Gropp et al. created cubane-like linkers from 1,4-boronophenylphosphonic acid that could condense to make COFs with a valency of 8 or, by adding acid, could form large, single crystals with an infinite-rod topology.










地球物理学Geophysics






Deep abiotic weathering of pyrite



黄铁矿的深层非生物风化作用



▲ 作者：Xin Gu, Peter J. Heaney, Fabio D. A. Aar?o Reis, Susan L. Brantley



▲ 链接：







▲ 摘要



黄铁矿，也被称为愚人金，是一种硫化铁矿物，在岩石中很常见，但在今天的沉积物中几乎不存在。黄铁矿氧化迅速，是海洋中硫的主要来源，但它也是历史上地球大气中氧含量的一个表征物。



作者对页岩单元的黄铁矿氧化过程进行了一组详细的观察。他们发现，在溶解过程中，与压裂相关的侵蚀作用与氧气含量同样重要。



作者开发了一个可帮助确定地球过去条件的模型，可了解可能是稳定的黄铁矿以及微生物在氧化过程中的作用。



▲ Abstract



Pyrite, also called fool’s gold, is an iron sulfide mineral that is very commonly found in rock but is almost nonexistent in sediments today. Pyrite oxidizes quickly and is a major source of sulfur to the ocean, but it is also a proxy for the oxygen content historically in Earth’s atmosphere. Gu et al. conducted a set of detailed observations of the pyrite oxidation process in a shale unit. The authors found that erosion tied to fracturing is just as important as the oxygen content for the dissolution process. They developed a model that helps determine the conditions in Earth’s past for which pyrite might have been stable and the role of microorgani**s in the oxidation process.










Triple iron isotope constraints on the role of ocean iron sinks in early atmospheric oxygenation



三铁同位素对海洋铁汇在早期大气氧化作用的限制



▲ 作者：Andy W. Heard, Nicolas Dauphas, Romain Guilbaud, Olivier J. Rouxel, Ian B. Butler, Nicole X. Nie



▲ 链接：







▲ 摘要



在地球早期的历史中，哪些因素控制了大气中氧气（O2）的积累？



作者利用38亿至23亿年前太古宙-古元古代沉积物的高精密铁同位素测量，以及实验室合成黄铁矿的数据表明，黄铁矿或硫化铁埋藏可能导致O2净出口。



因此，这些反应可能促成了大约24亿年前开始的大氧化事件之前的短暂氧化的早期片段。



▲ Abstract



What factors controlled the accumulation of atmospheric oxygen gas (O2) early in the history of Earth? Heard et al. used high-precision iron isotopic measurements of Archean-Paleoproterozoic sediments, with ages between 3.8 billion and 2.3 billion years ago, and laboratory data about synthetic pyrites to show that pyrite, or iron sulfide, burial could have resulted in net O2 export. These reactions therefore may have contributed to early episodes of transient oxygenation before the Great Oxidation Event that began about 2.4 billion years ago.










生物学Biology










Social selectivity in aging wild chimpanzees



年老野生黑猩猩的社会选择性



▲ 作者：Alexandra G. Rosati, Lindsey Hagberg, Drew K. Enigk, Emily Otali, Melissa Emery Thompson, Martin N. Muller, Richard W. Wrangham, Zarin P. Machanda



▲ 链接：







▲ 摘要



随着年龄的增长，人们会优先建立积极的友谊，而不是年轻时新的但有风险的社交活动。据推测，这种转变可能是由于人们自己对死亡的感觉开始产生。



作者分析了一个罕见的、长期的雄性黑猩猩社会关系数据集，发现了一个非常相似的关注于老的和积极的友谊。



虽然有证据表明非人类动物有一定的时间感，但它们似乎不太可能像人一样有濒死的感觉；因此，这些结果表明，一种不同的、更深层的机制可能在起作用。



▲ Abstract



As humans age, we prioritize established positive friendships over the new, but risky, socializing we do when we are young. It has been hypothesized that this shift may come as our own sense of mortality kicks in. Rosati et al. **yzed a rare, long-term dataset on social bonds among male chimpanzees and found a very similar focus on old and positive friendships. Though there is evidence of some sense of time among nonhuman animals, it seems unlikely that they have the same impending sense of mortality that we experience; thus, these results suggest that a different, and deeper, mechani** may be at play.






Experimental evolution makes microbes more cooperative with their local host genotype



实验进化使微生物与其本地宿主基因型更加合作



▲ 作者：Rebecca T. Batstone, Anna M. O’Brien, Tia L. Harrison, Megan E. Frederickson



▲ 链接：







▲ 摘要



许多豆科植物与固氮细菌或根瘤菌有寄主共生关系，这对植物和微生物都有好处。



作者通过实验研究了五种豆科植物菌株与不同细菌分离株之间的关系。与其观察宿主对细菌结合的选择（宿主选择），突变在细菌质粒中积累并增加了共生的强度。



因此，细菌菌株和植物基因型之间的局部和近期联系是由于细菌适应的选择。



▲ Abstract



Many legumes have a host-symbiote relationship with nitrogen-fixing bacteria, or rhizobia, that provides a benefit to both the plant and the microbe. Batstone et al. experimentally evolved the association between five legume accessions and different bacterial isolates. Rather than observe selection by the host for bacterial associations (host choice), mutations accumulated within a bacterial pla**id and increased the strength of the mutuali**. Thus, local and recent associations between bacterial strains and plant genotypes are due to selection for bacterial adaptation.










电物理Electric Physics










Metasurface-driven OLED displays beyond 10,000 pixels per inch



超表面驱动的OLED显示器每英寸超1万像素



▲ 作者：Won-Jae Joo, Jisoo Kyoung, Majid Esfandyarpour, Sung-Hoon Lee, Hyun Koo, Sunjin Song, Young-Nam Kwon, Seok Ho Song, Jun Cheol Bae, Ara Jo, Myong-Jong Kwon, Sung Hyun Han, Sung-Han Kim, Sungwoo Hwang



▲ 链接：







▲ 摘要



有机发光二极管（OLEDs）广泛应用于高分辨率、大面积电视以及智能手机和平板电脑的手持显示器。



由于屏幕距离眼睛有一定距离，每英寸的像素数通常在数百左右。对于近眼微显示器——例如，在虚拟和增强现实应用中——所需的像素密度达到每英寸几千像素，目前的显示技术无法满足。



作者开发了一种全彩、高亮度的OLED设计，该设计基于工程超表面作为可调谐的反光镜。每英寸10000像素的超高密度很容易满足下一代可在眼镜或隐形眼镜上制作的微显示器的要求



▲ Abstract



Organic light-emitting diodes (OLEDs) have found wide application in high-resolution, large-area televisions and the handheld displays of **artphones and tablets. With the screen located some distance from the eye, the typical number of pixels per inch is in the region of hundreds. For near-eye microdisplays—for example, in virtual and augmented reality applications—the required pixel density runs to several thousand pixels per inch and cannot be met by present display technologies. Joo et al. developed a full-color, high-brightness OLED design based on an engineered metasurface as a tunable back-reflector. An ultrahigh density of 10,000 pixels per inch readily meets the requirements for the next-generation microdisplays that can be fabricated on glasses or contact lenses.










材料物理Material Physics










Super twisted spirals of layered materials enabled by growth on non-Euclidean surfaces



在非欧几里得表面上生长的层状材料的超扭曲螺旋



▲ 作者：Yuzhou Zhao, Chenyu Zhang, Daniel D. Kohler, Jason M. Scheeler, John C. Wright, Paul M. Voyles, Song Jin



▲ 链接：







▲ 摘要



尽管缺陷或晶格失配会导致变形，但扁平基底上的层状材料的生长通常发生在堆叠层中。然而，这些影响通常很小，可以不受控制。



作者证明了合成多层二维材料的可能性，由于螺旋位错的存在与弯曲衬底表面结合，在层之间产生一定的扭曲。



不同的扭曲角度是通过改变表面的非平面度和特性（圆锥或双曲）来实现的。



▲ Abstract



The growth of layered materials on flat substrates usually occurs in stacked layers, although defects or a lattice mi**atch can induce strains that distort the shape of subsequent layers. However, these effects are usually **all and can be uncontrolled. Zhao et al. now demonstrate the possibility of synthesizing multilayers of two-dimensional materials with certain twists between the layers induced by the presence of screw dislocations in combination with curved substrate surfaces. Different twist angles are achieved by varying the amount of nonplanarity and the character （conical or hyperbolic） of the surface.