乐鱼,《科学》（20230721出版）一周论文导读
编译 | 冯维维
Science, Volume 381, Issue 6655, 21 Jul 2023
《科学》2023年7月21日，第381卷，6655期
化学Chemistry
In situ photocatalytically enhanced thermogalvanic cells for electricity and hydrogen production
用在发电和制氢的原位光催化加强型热原电池
▲ 作者：Yijin Wang, Youzi Zhang, Xu Xin, Jiabao Yang, Maohuai Wang, Ruiling Wang, Peng Guo, Wenjing Huang, Ana Jorge Sobrido, and Xuanhua Li
▲ 链接：
https://www.science.org/doi/10.1126/science.adg0164
▲ 摘要：
高机能热电电池具有将热能转化为电能的潜力，但其效力遭到氧化还原离子浓度差低的限制。研究者报导了一种原位光催化加强氧化还原反映，该反映发生氢和氧，以实现热电器件中氧化还原离子的持续浓度梯度。热功率与产氢率之间的线性关系是装配设想的根基准绳。
该系统的热功率为8.2毫伏/开尔文，太阳能制氢效力高达0.4%。由36个单位构成的年夜面积发机电（112平方厘米）在室外运转6小时后，发生了4.4伏的开路电压和20.1毫瓦的功率，和0.5毫摩尔的氢气和0.2毫摩尔的氧气。
▲ Abstract：
High-performance thermogalvanic cells have the potential to convert thermal energy into electricity, but their effectiveness is limited by the low concentration difference of redox ions. We report an in situ pho����APPtocatalytically enhanced redox reaction that generates hydrogen and oxygen to realize a continuous concentration gradient of redox ions in thermogalvanic devices. A linear relation between thermopower and hydrogen production rate was established as an essential design principle for devices. The system exhibited a thermopower of 8.2 millivolts per kelvin and a solar-to-hydrogen efficiency of up to 0.4%. A large-area generator (112 square centimeters) consisting of 36 units yielded an open-circuit voltage of 4.4 volts and a power of 20.1 milliwatts, as well 0.5 millimoles of hydrogen and 0.2 millimoles of oxygen after 6 hours of outdoor operation.
Fluorochemicals from fluorspar via a phosphate-enabled mechanochemical process that bypasses HF
绕过氟化氢，经由过程磷酸盐激活机器化学进程从萤石中提取氟化学品
▲ 作者：CALUM PATEL, EMY ANDRé-JOYAUX, JAMIE A. LEITCH, XABIER MARTíNEZ DE IRUJO-LABALDE, FRANCESCO IBBA, JOB STRUIJS, MATHIAS A. ELLWANGER, ROBERT PATON, DUNCAN L. BROWNE, AND VéRONIQUE GOUVERNEUR
▲ 链接：
https://www.science.org/doi/10.1126/science.adi1557
▲ 摘要：
所有含氟化学物资——包罗元素氟和亲核、亲电和自在基氟化试剂——都是由氟化氢（HF）制备的。这类剧毒和侵蚀性气体是由酸级氟石（>97% CaF2）与硫酸在卑劣前提下反映发生的。
经由过程绕过氟化氢的工艺利用萤石出产含氟化学品长短常可取的，但因为CaF2的不溶性，这依然是一个未处理的问题。受磷酸钙生物矿化的开导，研究者公然了一种在机器化学前提下用磷酸氢二钾（K2HPO4）处置酸级萤石的方案。生成的固体能够在酒精溶剂中与亲电反映物构成碳氟键和硫氟键。
▲ Abstract：
All fluorochemicals—including elemental fluorine and nucleophilic, electrophilic, and radical fluorinating reagents—are prepared from hydrogen fluoride (HF). This highly toxic and corrosive gas is produced by the reaction of acid-grade fluorspar (>97% CaF2) with sulfuric acid under harsh conditions. The use of fluorspar to produce fluorochemicals via a process that bypasses HF is highly desirable but remains an unsolved problem because of the prohibitive insolubility of CaF2. Inspired by calcium phosphate biomineralization, we herein disclose a protocol of treating acid-grade fluorspar with dipotassium hydrogen phosphate (K2HPO4) under mechanochemical conditions. The process affords a solid composed of crystalline K3(HPO4)F and K2?xCay(PO3F)a(PO4)b, which is found suitable for forging sulfur-fluorine and carbon-fluorine bonds.
Programming correlated magnetic states with gate-controlled moiré geometry
门控磁栅几何相干磁态编程
▲ 作者：ERIC ANDERSON, FENG-REN FAN, JIAQI CAI, WILLIAM HOLTZMANN, TAKASHI TANIGUCHI, KENJI WATANABE, DI XIAO, WANG YAO, AND XIAODONG XU
▲ 链接：
https://www.science.org/doi/10.1126/science.adg4268
▲ 摘要：
节制系统的根基晶格几何布局的能力可能使新兴量子基态之间的转换成为可能。研究者报导了在菱形堆叠的二碲化钼（MoTe2）莫尔双层中，电子多体哈密顿量在蜂窝和三角形晶格几何之间的原位栅极切换，发生可切换的磁互换彼此感化。在零电场下，他们不雅察到一个相干的铁磁绝缘体接近一个空穴，居里温度可普遍调理，最高可达14K。
施加电场将系统转换成一个半填充的三角形晶格，具有反铁磁彼此感化；进一步搀杂该层极化超晶格使反铁磁互换彼此感化恢复为铁磁。研究证实了菱形堆叠MoTe2 莫尔双层是一个具有非普通拓扑的项目相干状况的尝试室。
▲ Abstract：
The ability to control the underlying lattice geometry of a system may enable transitions between emergent quantum ground states. We report in situ gate switching between honeycomb and triangular lattice geometries of an electron many-body Hamiltonian in rhombohedral (R)–stacked molybdenum ditelluride (MoTe2) moiré bilayers, resulting in switchable magnetic exchange interactions. At zero electric field, we observed a correlated ferromagnetic insulator near one hole per moiré unit cell with a widely tunable Curie temperature up to 14 K. Applying an electric field switched the system into a half-filled triangular lattice with antiferromagnetic interactions; further doping this layer-polarized superlattice tuned the antiferromagnetic exchange interaction back to ferromagnetic. Our work demonstrates R-stacked MoTe2moirés to be a laboratory for engineering correlated states with nontrivial topology.
地质学Geology
The precursory phase of large earthquakes
年夜地动的预兆
▲ 作者：QUENTIN BLETERY AND JEAN-MATHIEU NOCQUET
▲ 链接：
https://www.science.org/doi/10.1126/science.adg2565
▲ 摘要：
在年夜地动之前，断层上是不是具有可不雅测到的预兆滑动，人们已争辩了几十年。固然在几回年夜地动之前的不雅测被认为是预兆滑动的可能目标，但这些不雅测其实不间接产生在地动之前，在年夜大都事务之前也没有看到，并且凡是也没有在地动以后不雅测到。
研究者对GPS数据中的短时间预兆滑动进行了全球搜刮，总结了在90次地动（矩级≥7）前48小时内，由3026个高速度GPS时候序列丈量到的位移——投影到震源预兆滑动预期的标的目的上。该方式揭露了分裂前约2小时长的滑动指数加快度，注解年夜地动始在滑动的预兆阶段，丈量精度和密度的改良能够更有用地检测和监测。
▲ Abstract：
The existence of an observable precursory phase of slip on the fault before large earthquakes has been debated for decades. Although observations preceding several large earthquakes have been proposed as possible indicators of precursory slip, these observations do not directly precede earthquakes, are not seen before most events, and are also commonly observed without being followed by earthquakes. We conducted a global search for short-term precursory slip in GPS data. We summed the displacements measured by 3026 high-rate GPS time series—projected onto the directions expected from precursory slip at the hypocenter—during 48 hours before 90 (moment magnitude ≥7) earthquakes. Our approach reveals a ≈2-hour-long exponential acceleration of slip before the ruptures, suggesting that large earthquakes start with a precursory phase of slip, which improvements in measurement precision and density could more effectively detect and possibly monitor.
Deglaciation of northwestern Greenland during Marine Isotope Stage 11
海洋同位素阶段11时代格陵兰岛西北部的消冰感化
▲ 作者：ANDREW J. CHRIST, TAMMY M. RITTENOUR, PAUL R. BIERMAN, BENJAMIN A. KEISLING, PAUL C. KNUTZ, TONNY B. THOMSEN, NYNKE KEULEN, JULIE C. FOSDICK, SIDNEY R. HEMMING, AND ELIZABETH K. THOMAS
▲ 链接：
https://www.science.org/doi/10.1126/science.ade4248
▲ 摘要：
对格陵兰岛西北部世纪营冰芯的冰下堆积物的丈量注解，在年夜约40万年前的间冰期，这个处所是无冰的。研究者操纵发光测年和宇宙成因核素数据注解，这些堆积物是在不到1.6万年前表露在阳光下，在无冰前提下堆积的。
这个处所没有冰，意味着格陵兰冰盖必然形成了跨越1.4米的海平面上升，相当在高海平面，那时全球平均气温与当前行将履历的人类酿成的天气变暖类似。
▲ Abstract：
Measurements made on subglacial sediment from the Camp Century ice core in northwestern Greenland show that the location was ice free during the interglacial that occurred around 400,000 years ago. Christ et al. used luminescence dating and cosmogenic nuclide data to show that the sediment was deposited under ice-free conditions after having been exposed at the surface to sunlight fewer than 16,000 years earlier. The absence of ice at that location means that the Greenland Ice Sheet must have contributed more than 1.4 meters of sea-level equivalent to the high sea-level stand, when the average global air temperature was similar to what we will soon experience because of human-caused climate warming.
微生物MicroBiology
Emergent coexistence in multispecies microbial communities
多物种微生物群落的共存
▲ 作者：CHANG-YU CHANG, DJORDJE BAJI?, JEAN C. C. VILA, SYLVIE ESTRELA, AND ALVARO SANCHEZ
▲ 链接：
https://www.science.org/doi/10.1126/science.adg0727
▲ 摘要：
领会保持微生物的生物多样性机制是生态学的要害欲望。曩昔关在微生物共存的研究首要集中在物种对上，但尚不清晰在多物种群落中是不是需要孤立的成对共存。为领会决这个问题，研究者在体外对12个分歧富集群落中不变共存的成员进行了数百次成对合作尝试。
为了肯定这些尝试的成果，他们开辟了一个主动图象阐发管道来量化物种品貌。研究发觉，合作排挤是最多见的成果，它具有很强的条理性和可传送性。
因为在不变的多物种群落中共存的很多物种在不异前提下没法在成对共培育中共存，并就此得出结论，多物种共存是一种告急现象。这项研究强调了地点社会布景对理解复杂生态系统中共存发源的主要性。
▲ Abstract：
Understanding the mechanisms that maintain microbial biodiversity is a critical aspiration in ecology. Past work on microbial coexistence has largely focused on species pairs, but it is unclear whether pairwise coexistence in isolation is required for coexistence in a multispecies community. To address this question, we conducted hundreds of pairwise competition experiments among the stably coexisting members of 12 different enrichment communities in vitro. To determine the outcomes of these experiments, we developed an automated image analysis pipeline to quantify species abundances. We found that competitive exclusion was the most common outcome, and it was strongly hierarchical and transitive. Because many species that coexist within a stable multispecies community fail to coexist in pairwise co-culture under identical conditions, we concluded that multispecies coexistence is an emergent phenomenon. This work highlights the importance of community context for understanding the origins of coexistence in complex ecosystems.
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