"Nature" (published 20220901) One -week thesis guide

Compilation | Li Yan

Nature, 1 september 2022, volume 609 Issue 7925

"Nature" September 1, 2022, Vol. 609, 7925

Material Science Material Science

Aligned Macrocycle Pores in Ultrathin Films for Accurate Molecular Sieving

Precision of the large ring holes in the ultra -thin film

Author: zhiwei jiang, ruijiao dong, Austin M. Evans et al.

Link:

https://www.nature.com/articleS/S41586-022-05032-1

Summary:

Here, we have synthesized a large -scale loop of selective functionalization. It has a differentiation reactivity and is prioritized. It can form a good hole on the ultra -thin nanoconal membrane. By reducing the thickness of the nanofilat to a few nanometers, this orderly structure has been enhanced.

This directional structure makes the direct visualization of nano -membrane surface -level large cycle pores possible. By changing the characteristics of the large cycle, the size can be accurately reached. Compared with the disorderly large -ring film, the orientation large ring membrane has twice the methanol permeability and higher selectivity.

Used in high -value separation, such as enriching marijuana phenol oil, they realize a magnificent ethanol transmission and three times the enrichment of three times higher than commercial membranes. This method provides a feasible strategy for creating the Namic channel in the aggregate film and proves its potential in the separation of precision molecules.

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 ångströmprecision 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

The alien super crystal that has a large anti -often Hall effect in the face

Author: jiadong zhou, wenjie zhang, yung-chang lin et al.

Link:

https://www.nature.com/articleS/S41586-022-05031-2 Abstract:

Here, we reported a kind of alien super crystal composed of two -dimensional sulfide (VS2) and one -dimensional sulfur (VS) chain that was deposited directly through chemical gas phase deposition. This unique super crystal has unconventional 1T stacks, and identifies the single -inclined unit cells of sulfide/sulfide layer by scanning transmitting electron microscope.

When the magnetic field is on the plane, an unexpected Hall effect can be observed, and its duration can reach 380 Cairvin. In this case, the Hall effect usually disappears.

The observation of this effect is supported by theoretical calculation, which can be attributed to the unconventional anti -Chang Hall effect caused by the one -dimensional sulfur chain, which is induced by the inner magnetic field. Our work expands the traditional understanding of the super crystal and will promote the synthesis of more super -structures.

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 Stimulating The Synthesis of More ExtraordInary Superstructures.

Earth Science Earth Science

Enhanced Ocean OxyGenation During Cenozoic Warm Periods

New generation warm -stage marine oxygen combination enhancement

Author: Alexandra Auderset, Simone Moretti, BJörn Taphorn et al.

Link:

https://www.nature.com/articleS/S41586-022-05017-0

Summary:

Here, we use pores -binding -in -nitrogen isotopes to show that the moderate and early -period climate period (MMCO) and early new climate period (EECO) have a significant weakened nitrification effect during the east of the northern Pacific body.

Because the nitrification effect is limited to the hypoxic waters, our results show that in the continuous warmth period of these two new generations, the hypoxia areas are reduced, not expansion. The narrowing area of ​​hypoxia may be due to the decline in biological productivity caused by rising tropical Pacific Ocean, which will reduce underground oxygen demand.

In addition, the promotion of deep -sea ventilation may weaken the "biological carbon pump" of the ocean, thereby increasing the oxygen content of deep sea. This mechanism determines that the reduction of the hypoxia areas occurs synchronized with climate warming, or it takes several centuries or thousands of years to form. Therefore, although the results we have from the new generation are not necessarily applicable to the recent future, they may mean that global warming may eventually lead to a reduction in hypoxia.

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 Cenozoice Do NOT NECESSARILY Apply The Near-Term Future, They Might Imply that Global Warming May Eventually Caunts Odz Contraction.

Precursor-Free Eruption Triggered by Edifice Ruture at Nyiragongo Volcano

The unprovoral eruption caused by the rupture of the Niragonor volcano structure

Author: d. Smittarelo, B. Smets, J. Barrière, C. Michellier et al.

Link:

https://www.nature.com/articleS/S41586-022-05047-8

Summary:

The classic mechanism of volcanic eruption mainly involves pressure accumulation and magma to rise to the surface. Earth physics and global chemical signals generated by this process can be detected and interpreted as a precursor of eruption. The Nilaguo volcano, located in the Democratic Republic of the Congo, is a volcano that opens the magma pipeline system. There is a continuous lava lake in the crater at the top of it.

On May 22, 2021, it generated about 6 hours without obvious prelude, and then -instead of the previous -magma side movement entered the crust, shaking this explanation. Here, we show that this reversal sequence is likely to be caused by the rupture of the building, which produces a fatal lava flow and triggers a large number of rock veins of 25 kilometers long.

The rock vein extends south of the Gobma (the Republic of the Democratic Republic of the Congo) and the city of Geseni (Rwanda) and below the Lake Kuwu. This time the volcanic crisis raised new problems on controlling this eruption mechanism, and may face more dangerous problems, such as eruption in the densely populated urban areas, deep -sea magma activities, or the eruption of lakes in the Kuhu Lake with rich natural gas. This time, it also emphasizes that when a large amount of magma is stored near the ground, the challenges of open -air volcano faced in monitoring, early detection and risk management.

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 MechanisSms Contro lling 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 protrly forests

Forest protection strategy

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

Link:

https://www.nature.com/articleS/S41586-022-05096-z z

Summary:

Here, we use dynamic optimization methods to determine the best sequence of plant species in 458 forest ecological zones around the world in the next 50 years. Optimization strategy elements include the richness of the species of each forest ecological area, the complementary nature of the species in each ecological area, the protection cost of increased with the cumulative protection of an ecological area, the existing degree of protection, the speed of cutting the forest, and the ecology of each ecology The potential of regional rejuvenation.

The optimal protection strategy of this plan was originally aimed at a few ecological areas. Further cutting of these areas will lead to a large reduction in species, and the cost of protection is lower. In the following years, the protection of the protection work can be extended to more ecological areas and invested in expanding the protection of virgin forests and re -afforestation.

The biggest progress of species protection is Moranica, South Asia and Southeast Asia, Anatolia Peninsula, northern South America and Central America. The results of this research emphasize that through targeted and careful investment, huge potential returns can be obtained in protecting the environment.

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 American. The Results Highlight The Potentially Large Gains in Conservation that can be made with caretargeted investments.

Paleoanthropology

Postcranial Evidence of Late Miocene Hominin Bipedalism in Chad

Alphabetic evidence of the ancient human beings walking upright in the evening of Chad

Author: G. DAVER, F. Guy, H. T. Mackaye, A. Likius, J. -R. Boisserie, A. Mousea, L. Pallas, P. Vignaud n. D. Clarisse

Link:

https://www.nature.com/articleS/S41586-022-04901-z

Summary:

Here, we put forward the evidence of the Chadsha's movement of the movement of the Shatha people, and had a new discovery of the two -foot walking in the early stages of ancient human evolution. The original material was found in TM 266 in the Toros-Menalla fossil area, with a left femoral and a pair of ulnar. The habits of femoral shapes are similar to the habits of walking, and the ruler preserves evidence of a large number of trees climbing behavior.

In summary, these findings show that ancient humans have been walking in both feet in about 7 million years, but it also shows that climbing on the tree may be an important part of their sports skills.

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 armeral clambering was probably a significant part of their locomotor re Pertoire.

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