编译 | 李言

Nature, 1 September 2022, Volume 609 Issue 7925

《自然》2022年9月1日，第609卷，7925期

材料科学Material Science

Aligned macrocycle pores in ultrathin films for accurate molecular sieving

超薄膜中定向大环孔的精确分子筛分

 作者：Zhiwei Jiang, Ruijiao Dong, Austin M. Evans et al.

 链接：

https://www.nature.com/articles/s41586-022-05032-1

 摘要：

在此，我们合成了选择性功能化的大环，它具有分化的反应性，优先排列，在超薄纳米膜上能形成良好的孔。通过将纳米膜厚度降低到几纳米，这种有序结构得到了增强。

这种定向结构使纳米膜表面亚纳米级大周期孔隙的直接可视化成为可能，通过改变大周期特性，尺寸可精确到埃。与无序的大环膜相比，定向的大环膜具有两倍的甲醇渗透性和更高的选择性。

在高值分离中使用，例如富集大麻二酚油，它们实现了一个数量级的乙醇传输和比商业先进的膜高三倍的富集。这种方法为在聚合物膜中创建亚纳米通道提供了一种可行的策略，并证明了其在精确分子分离方面的潜力。

Abstract：

Here, we synthesized selectively functionalized macrocycles with differentiated reactivities that preferentially aligned to create well-defined pores across an ultrathin nanofilm. The ordered structure was enhanced by reducing the nanofilm thickness down to several nanometres. This orientated architecture enabled direct visualization of subnanometre macrocycle pores in the nanofilm surfaces, with the size tailored to ångström precision by varying the macrocycle identity. Aligned macrocycle membranes provided twice the methanol permeance and higher selectivity compared to disordered counterparts. Used in high-value separations, exemplified here by enriching cannabidiol oil, they achieved one order of magnitude faster ethanol transport and threefold higher enrichment than commercial state-of-the-art membranes. This approach offers a feasible strategy for creating subnanometre channels in polymer membranes, and demonstrates their potential for accurate molecular separations.

Heterodimensional superlattice with in-plane anomalous Hall effect

具有面内大反常霍尔效应的异维超晶格

 作者：Jiadong Zhou, Wenjie Zhang, Yung-Chang Lin et al.

 链接：

https://www.nature.com/articles/s41586-022-05031-2

 摘要：

在此，我们报告了一种直接通过化学气相沉积沉积的、由二维二硫化钒（VS2）和一维硫化钒（VS）链相互交叉排列组成的本征异维超晶格。这种独特的超晶格具有非常规的1T叠加，通过扫描透射电子显微镜识别出二硫化钒/硫化钒层的单斜单元细胞。

当磁场在平面上时，可以观察到一个意想不到的霍尔效应，其持续时间可达380开尔文，在这种情况下，霍尔效应通常会消失。

这一效应的观测得到了理论计算的支持，可以归因于与一维硫化钒链有关的、由面内磁场诱导的面外贝里曲率引起的非常规反常霍尔效应。我们的工作扩展了对超晶格的传统理解，并将促进更多超结构的合成。

Abstract：

Here we report an intrinsic heterodimensional superlattice consisting of alternating layers of two-dimensional vanadium disulfide (VS2) and a one-dimensional vanadium sulfide (VS) chain array, deposited directly by chemical vapour deposition. This unique superlattice features an unconventional 1T stacking with a monoclinic unit cell of VS2/VS layers identified by scanning transmission electron microscopy. An unexpected Hall effect, persisting up to 380 kelvin, is observed when the magnetic field is in-plane, a condition under which the Hall effect usually vanishes. The observation of this effect is supported by theoretical calculations, and can be attributed to an unconventional anomalous Hall effect owing to an out-of-plane Berry curvature induced by an in-plane magnetic field, which is related to the one-dimensional VS chain. Our work expands the conventional understanding of superlattices and will stimulate the synthesis of more extraordinary superstructures.

地球科学Earth science

Enhanced ocean oxygenation during Cenozoic warm periods

新生代暖期海洋氧合增强

 作者：Alexandra Auderset, Simone Moretti, Björn Taphorn et al.

 链接：

https://www.nature.com/articles/s41586-022-05017-0

 摘要：

在此，我们利用有孔虫结合态氮同位素表明，中新世中期气候适宜期（MMCO）和早始新世气候适宜期（EECO）期间热带北太平洋东部水体反硝化作用显著减弱。

由于反硝化作用仅限于缺氧水域，我们的结果表明，在这两个新生代的持续温暖期，缺氧区是缩小的，而不是扩张的。缺氧区缩小可能是由于热带太平洋上升流引起的生物生产力下降，这将减少地下的氧气需求。

此外，南大洋促进深海通风可能削弱了海洋的“生物碳泵”，从而增加了深海含氧量。这一机制决定了缺氧区的缩小是与气候变暖同步发生的，或是需要几个世纪或几千年的时间才能形成。

因此，虽然我们从新生代得出的结果不一定适用于近期的未来，但它们可能意味着全球变暖最终可能导致缺氧区缩小。

Abstract：

Here we use foraminifera-bound nitrogen (N) isotopes to show that water-column denitrification in the eastern tropical North Pacific was greatly reduced during the Middle Miocene Climatic Optimum (MMCO) and the Early Eocene Climatic Optimum (EECO). Because denitrification is restricted to oxygen-poor waters, our results indicate that, in these two Cenozoic periods of sustained warmth, ODZs were contracted, not expanded. ODZ contraction may have arisen from a decrease in upwelling-fuelled biological productivity in the tropical Pacific, which would have reduced oxygen demand in the subsurface. Alternatively, invigoration of deep-water ventilation by the Southern Ocean may have weakened the ocean’s ‘biological carbon pump’, which would have increased deep-ocean oxygen. The mechanism at play would have determined whether the ODZ contractions occurred in step with the warming or took centuries or millennia to develop. Thus, although our results from the Cenozoic do not necessarily apply to the near-term future, they might imply that global warming may eventually cause ODZ contraction.

Precursor-free eruption triggered by edifice rupture at Nyiragongo volcano

尼拉贡戈火山结构破裂引发的无前兆喷发

 作者：D. Smittarello, B. Smets, J. Barrière, C. Michellier et al.

 链接：

https://www.nature.com/articles/s41586-022-05047-8

 摘要：

火山喷发的经典机制主要涉及压力积累和岩浆向地表上升。这种过程产生的地球物理和地球化学信号可以被探测到并解释为喷发前兆。位于刚果民主共和国的尼拉贡戈火山是一座敞开岩浆管道系统的火山，其顶部的火山口内有一个持续的熔岩湖。

2021年5月22日，它在没有明显的前奏的情况下产生了大约6小时的侧面喷发，随后——而不是之前——岩浆侧向运动进入地壳，动摇了这种解释。在此，我们表明这种逆转的序列极有可能是由建筑物的破裂引发的，产生了致命的熔岩流，并引发了长达25公里的大量岩脉入侵。

该岩脉在戈马（刚果民主共和国）和吉塞尼（卢旺达）城市以及基伍湖下方的极浅深度（不到500米）向南延伸。这次火山危机对控制这种喷发的机制提出了新的问题，并可能面临更危险的问题，

例如在人口密集的城市地区的喷发、深海岩浆活动或天然气丰富的基伍湖的湖泊喷发。这次还更普遍地强调了当大量岩浆储存在接近地表的地方时，露天火山在监测、早期探测和风险管理方面面临的挑战。

Abstract：

Classical mechanisms of volcanic eruptions mostly involve pressure buildup and magma ascent towards the surface. Such processes produce geophysical and geochemical signals that may be detected and interpreted as eruption precursors. On 22 May 2021, Mount Nyiragongo (Democratic Republic of the Congo), an open-vent volcano with a persistent lava lake perched within its summit crater, shook up this interpretation by producing an approximately six-hour-long flank eruption without apparent precursors, followed—rather than preceded—by lateral magma motion into the crust. Here we show that this reversed sequence was most likely initiated by a rupture of the edifice, producing deadly lava flows and triggering a voluminous 25-km-long dyke intrusion. The dyke propagated southwards at very shallow depth (less than 500 m) underneath the cities of Goma (Democratic Republic of the Congo) and Gisenyi (Rwanda), as well as Lake Kivu. This volcanic crisis raises new questions about the mechanisms controlling such eruptions and the possibility of facing substantially more hazardous events, such as effusions within densely urbanized areas, phreato-magmatism or a limnic eruption from the gas-rich Lake Kivu. It also more generally highlights the challenges faced with open-vent volcanoes for monitoring, early detection and risk management when a significant volume of magma is stored close to the surface.

When and where to protect forests

森林保护策略

 作者：Ian H. Luby, Steve J. Miller Stephen Polasky

 链接：

https://www.nature.com/articles/s41586-022-05096-z

 摘要：

在此，我们利用动态优化方法确定了未来50年全球458个森林生态区植物物种保护的最佳序列。优化策略要素包括每个森林生态区域的物种丰富度、各生态区域的物种互补性、随着一个生态区域的累积保护而增加的保护成本、现有的保护程度、砍伐森林的速度和每个生态区域重新造林的潜力。

这一方案的最佳保护策略最初针对的是少数生态区域，这些区域的进一步砍伐会导致物种的大量减少，而且保护的成本较低。在后来的几年里，保护工作扩展可以到更多的生态区域，并投资于扩大保护原始森林和重新造林。

物种保护取得最大进展的地区是美拉尼西亚、南亚和东南亚、安纳托利亚半岛、南美洲北部和中美洲。这一研究结果强调，通过有针对性的精心投入，可以在保护环境方面取得巨大的潜在收益。

Abstract：

Here we use a dynamic optimization approach to identify an optimal sequence for the conservation of plant species in 458 forested ecoregions globally over the next 50 years. The optimization approach includes species richness in each forested ecoregion, complementarity of species across ecoregions, costs of conservation that rise with cumulative protection in an ecoregion, the existing degree of protection, the rate of deforestation and the potential for reforestation in each ecoregion. The optimal conservation strategy for this formulation initially targets a small number of ecoregions where further deforestation leads to large reductions in species and where the costs of conservation are low. In later years, conservation efforts spread to more ecoregions, and invest in both expanded protection of primary forest and reforestation. The largest gains in species conservation come in Melanesia, South and Southeast Asia, the Anatolian peninsula, northern South America and Central America. The results highlight the potentially large gains in conservation that can be made with carefully targeted investments.

古人类学Paleoanthropology

Postcranial evidence of late Miocene hominin bipedalism in Chad

乍得中新世晚期古人类直立行走的颅后证据

 作者：G. Daver, F. Guy, H. T. Mackaye, A. Likius, J. -R. Boisserie, A. Moussa, L. Pallas, P. Vignaud N. D. Clarisse

 链接：

https://www.nature.com/articles/s41586-022-04901-z

 摘要：

在此，我们提出了乍得沙赫人运动行为的颅后证据，并对古人类进化史早期阶段的两足行走有了新的发现。

原始材料是在Toros-Menalla化石区TM 266处发现的，有一块左股骨和一对尺骨。股骨形态和双足行走的习惯相似，尺骨则保存了大量树木攀爬行为的证据。

综上所述，这些发现表明古人类在7百万年左右就已经是双足行走了，但也表明在树上攀爬可能是他们运动技能的重要组成部分。

Abstract：

Here we present postcranial evidence of the locomotor behaviour of S.?tchadensis, with new insights into bipedalism at the early stage of hominin evolutionary history. The original material was discovered at locality TM?266 of the Toros-Ménalla fossiliferous area and consists of one left femur and two, right and left, ulnae. The morphology of the femur is most parsimonious with habitual bipedality, and the ulnae preserve evidence of substantial arboreal behaviour. Taken together, these findings suggest that hominins were already bipeds at around 7?Ma but also suggest that arboreal clambering was probably a significant part of their locomotor repertoire.

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