编译 | 李言

Nature,做作周论 10 August 2023, Volume 620 Issue 7973

《做作》2023年8月10日
，第620卷，出书7973期

?文导

地舆学Astronomy

Sustained wet–dry cycling on early Mars

火星早期不断的干湿循环

▲ 作者 ：W. Rapin, G. Dromart, B. C. Clark et al.

▲ 链接 ：

https://www.nature.com/articles/s41586-023-06220-3

▲ 摘要 ：

在此，咱们陈说好奇号火星车在盖尔陨石坑的做作周论审核服从，表明在早期火星概况情景中爆发了高频率的出书干湿循环。咱们审核到在Y形衔接处衔接开掘出的文导具备硫酸盐富集的厘米级多边形山脊  ，记实了由于纪律强度的做作周论一再干湿循环而在别致泥浆中组成的裂痕  。

咱们的出书发现不是由撞击或者火山引起的无意偶尔水文行动，而是文导指向了火星早期不断的、周期性的做作周论，致使可能是出书季节性的天气
。此外 ，文导由于干湿循环可能增长宿世物聚合
，做作周论盖尔蒸发盆地可能特意有利于这些历程
 。出书

咱们审核到的文导多角形模子在物理以及光阴上与蒙脱石粘土向含硫酸盐地层的转变无关，这是一个全天下扩散的矿物过渡。这表明Noachian–Hesperian过渡时期（38 - 36亿年前）可能具备了相似地球的天气制度以及有利于宿世物进化的地情绪景。

▲ Abstract ：

Here we report observations by the Curiosity rover at Gale Crater indicating that high-frequency wet–dry cycling occurred in early Martian surface environments. We observe exhumed centimetric polygonal ridges with sulfate enrichments, joined at Y-junctions, that record cracks formed in fresh mud owing to repeated wet–dry cycles of regular intensity. Instead of sporadic hydrological activity induced by impacts or volcanoes, our findings point to a sustained, cyclic, possibly seasonal, climate on early Mars. Furthermore, as wet–dry cycling can promote prebiotic polymerization, the Gale evaporitic basin may have been particularly conducive to these processes. The observed polygonal patterns are physically and temporally associated with the transition from smectite clays to sulfate-bearing strata, a globally distributed mineral transition. This indicates that the Noachian–Hesperian transition (3.8-3.6 billion years ago) may have sustained an Earth-like climate regime and surface environments favourable to prebiotic evolution.

Martian dunes indicative of wind regime shift in line with end of ice age

火星沙丘表明，风向随着冰河时期的停止爆发修正

▲ 作者：Jianjun Liu, Xiaoguang Qin et al.

▲ 链接 ：

https://www.nature.com/articles/s41586-023-06206-1

▲ 摘要 ：

在这里，咱们揭示了祝融号探测器在穿梭火星乌托邦平原南部LDM地域时取患上的一组丈量服从。咱们发现了一个地层序列的证据，搜罗最后的barchan沙丘组成，表明东冬风及沙丘聚积物胶结 ，之后受到西北风的侵蚀，侵蚀barchan沙丘并发生配合的纵向沙丘，风向转变与冰河时期的停止相不同 。

这些服从与火星极地地层记实相不同，将有助于后退咱们对于火星今世天气历史的清晰。

▲ Abstract：

Here we present a suite of measurements obtained by the Zhurong rover during its traverse across the southern LDM region in Utopia Planitia, Mars. We find evidence for a stratigraphic sequence involving initial barchan dune formation, indicative of north-easterly winds, cementation of dune sediments, followed by their erosion by north-westerly winds, eroding the barchan dunes and producing distinctive longitudinal dunes, with the transition in wind regime consistent with the end of the ice age. The results are compatible with the Martian polar stratigraphic record and will help improve our understanding of the ancient climate history of Mars.

物理学Physics

Solid-body trajectoids shaped to roll along desired pathways

固体轨迹体被塑组成沿着期望道路转动的形态

▲ 作者 ：Yaroslav I. Sobolev, Ruoyu Don et al.

▲ 链接：

https://www.nature.com/articles/s41586-023-06306-y

▲ 摘要：

在此 ，咱们开拓了一种算法来妄想“轨迹体”，而后经由3D打印合计出的形态并跟踪它们的转动道路来验证这些妄想 ，搜罗那些挨近自己的物体，这样物体的品质中间就会间歇性地向上挪移。

咱们的钻研次若是出于好奇心，可是大少数道路的轨迹线的存在对于量子以及典型光学具分心想不到的影响
，由于量子比特 
、自旋以及光偏振的能源学可能精确地映射到轨迹线及其道路 。

▲ Abstract：

Here, we develop an algorithm to design such bodies—which we call ‘trajectoids’—and then validate these designs experimentally by three-dimensionally printing the computed shapes and tracking their rolling paths, including those that close onto themselves such that the body’s centre of mass moves intermittently uphill. Our study is motivated largely by fundamental curiosity, but the existence of trajectoids for most paths has unexpected implications for quantum and classical optics, as the dynamics of qubits, spins and light polarization can be exactly mapped to trajectoids and their paths.

质料迷信Material science

Oriented nucleation in formamidinium perovskite for

photovoltaics

光伏用甲脒钙钛矿的定向成核

▲ 作者 ：Pengju Shi, Yong Ding, Bin Ding et al.

▲ 链接
：

https://www.nature.com/articles/s41586-023-06208-z

▲ 摘要：

在此，咱们经由对于钙钛矿结晶历程的原位监测来陈说一种定向成核机制，该机制可能辅助防止不良相的存在
，并后退光伏器件在差距薄膜加工场景下的功能。该器件的功率转换功能为25.4%（经认证为25.0%） ，该模块的面积为27.83 cm2
，经认证的孔径功能为21.4% ，使人印象深入。

▲ Abstract ：

Here we use in situ monitoring of the perovskite crystallization process to report an oriented nucleation mechanism that can help to avoid the presence of undesirable phases and improve the performance of photovoltaic devices in different film-processing scenarios. The resulting device has a demonstrated power-conversion efficiency of 25.4% (certified 25.0%) and the module, which has an area of 27.83 cm2, has achieved an impressive certified aperture efficiency of 21.4%.

地球迷信Earth Science

Rift-induced disruption of cratonic keels drives kimberlite volcanism

裂谷引起的克拉通龙骨断裂驱动金伯利岩火山熏染

▲ 作者
：Thomas M. Gernon, Stephen M. Jones et al.

▲ 链接 
：

https://www.nature.com/articles/s41586-023-06193-3

▲ 摘要：

在此 ，咱们揭示了大少数跨逾越去 10 亿年的金伯利岩，在大陆割裂后约莫 3000 万年（Myr）喷发 ，表明与裂谷历程无关 。咱们的能源学以及合成模子表明，在裂谷历程中组成的物理上峻峭的岩石圈—软流圈领土（LABs）在软流圈中发生对于流不晃动性，这些对于流不晃动性飞快地向裂谷带外部迁移数百至数千公里。

这些不晃动性在大陆割裂后不断了数万万年，并破损了多少十公里厚的克拉通岩石圈（或者称龙骨)）基底的晃动。移位的龙骨被回流中热的、上涌的软流圈以及富含挥发物的龙骨的混合物所取代，导致减压部份消融。咱们的合计表明，这一历程可能发生小体积
、低度、富含挥发物的熔体，与金伯利岩的预期特色颇为挨近 。

总而言之，这些服从经由克拉通龙骨的渐进破损
，提供了金伯利岩喷发以及超大陆旋回之间的定量以及机械分割。

▲ Abstract ：

Here we show that most kimberlites spanning the past billion years erupted about 30 million years (Myr) after continental breakup, suggesting an association with rifting processes. Our dynamical and analytical models show that physically steep lithosphere–asthenosphere boundaries (LABs) formed during rifting generate convective instabilities in the asthenosphere that slowly migrate many hundreds to thousands of kilometres inboard of rift zones. These instabilities endure many tens of millions of years after continental breakup and destabilize the basal tens of kilometres of the cratonic lithosphere, or keel. Displaced keel is replaced by a hot, upwelling mixture of asthenosphere and recycled volatile-rich keel in the return flow, causing decompressional partial melting. Our calculations show that this process can generate small-volume, low-degree, volatile-rich melts, closely matching the characteristics expected of kimberlites. Together, these results provide a quantitative and mechanistic link between kimberlite episodicity and supercontinent cycles through progressive disruption of cratonic keels.

A cool runaway greenhouse without surface magma ocean

不地表岩浆陆地的凉爽失控温室模子

▲ 作者 ：Franck Selsis, Jérémy Leconte et al.

▲ 链接：

https://www.nature.com/articles/s41586-023-06258-3

▲ 摘要 ：

在此
，咱们陈说运用由辐射层组成纯蒸汽大气的天气模子，使其热妄想强烈依赖于恒星光谱以及外部热流
。当不施加绝热剖面时 ，概况温度较低；地壳的消融需要好比今高多少倍的日照，而这在太阳主序期是不会爆发的。

与以前的钻研服从相同，金星概况可能在大气逃逸以前凝聚。在最红的恒星（Teff < 3000 K）周围
，不论含水量若何，概况岩浆陆地都不能仅靠恒星的实力组成 。这一发现影响了蒸汽大气以及系内行星品质半径关连的可审核特色，极大修正了当初对于TRAPPIST-1行星含水量预料的限度因素。

对于低压不透明的新丈量，特意是远离H2O罗致带的丈量，蒸汽大气是类地行星演化的紧张阶段  ，对于美满蒸汽大气的模子是有需要的。

▲ Abstract
：

Here, we report using a consistent climate model that pure steam atmospheres are co妹妹only shaped by radiative layers, making their thermal structure strongly dependent on the stellar spectrum and internal heat flow. The surface is cooler when an adiabatic profile is not imposed; melting Earth’s crust requires an insolation several times higher than today, which will not happen during the main sequence of the Sun. Venus’s surface can solidify before the steam atmosphere escapes, which is the opposite of previous works. Around the reddest stars (Teff < 3,000 K), surface magma oceans cannot form by stellar forcing alone, whatever the water content. These findings affect observable signatures of steam atmospheres and exoplanet mass–radius relationships, drastically changing current constraints on the water content of TRAPPIST-1 planets. Unlike adiabatic structures, radiative–convective profiles are sensitive to opacities. New measurements of poorly constrained high-pressure opacities, in particular far from the H2O absorption bands, are thus necessary to refine models of steam atmospheres, which are important stages in terrestrial planet evolution.

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