2024, Volume 632 Issue 8024
《自然》2024年8月8日，第632卷，8024期
物理學Physics
Antiferromagnetic phase transition in a 3D fermionic Hubbard model
三維費米子哈伯德模型中的反鐵磁相變
▲ 作者：Hou-Ji Shao, Yu-Xuan Wang et al.
▲鏈接：
https://www.nature.com/articles/s41586-024-07689-2
▲摘要：
費米子哈伯德模型（FHM）描述了由強電子—電子相關性引起的廣泛的物理現象，包括非常規超導的推測機制。在此，我們報告了一個由鋰-6原子組成的三維費米子哈伯德系統的反鐵磁相變的觀察，該系統在一個均勻的光學晶格中有大約80萬個位點。當相互作用強度、溫度和摻雜濃度被微調到接近各自的臨界值時，我們觀察到自旋結構因子急劇增加。
這些觀察結果可以用冪律發散來解釋，從海森堡普適性類來看，其臨界指數為1.396。在半填充和最佳相互作用強度下，測得的自旋結構因子達到123(8)，表明了反鐵磁相的建立。我們的研究結果為探索FHM的低溫相圖提供了機會。
▲ Abstract：
The fermionic Hubbard model (FHM) describes a wide range of physical phenomena resulting from strong electron–electron correlations, including conjectured mechanisms for unconventional superconductivity. Here we report the observation of the antiferromagnetic phase transition in a three-dimensional fermionic Hubbard system comprising lithium-6 atoms in a uniform optical lattice with approximately 800,000 sites. When the interaction strength, temperature and doping concentration are finely tuned to approach their respective critical values, a sharp increase in the spin structure factor is observed. These observations can be well described by a power-law divergence, with a critical exponent of 1.396 from the Heisenberg universality class. At half-filling and with optimal interaction strength, the measured spin structure factor reaches 123(8), signifying the establishment of an antiferromagnetic phase. Our results provide opportunities for exploring the low-temperature phase diagram of the FHM.
材料科學Materials Science
Water- and heat-activated dynamic passivation for perovskite photovoltaics
鈣鈦礦光伏電池的水活化和熱活化動態鈍化
▲ 作者：Wei-Ting Wang, Philippe Holzhey et al.
▲鏈接：
https://www.nature.com/articles/s41586-024-07705-5
▲摘要：
在此，我們報告了一種使用阻礙脲/硫代氨基甲酸酯鍵Lewis酸堿材料（HUBLA）的活性鈍化策略，其中具有水和熱活化特性的動態共價鍵可以動態修復鈣鈦礦，以確保設備的性能和穩定性。暴露于濕氣或高溫下，HUBLA會產生新的試劑，并進一步鈍化鈣鈦礦中的缺陷。
這種鈍化策略實現了功率轉換效率（PCE）為25.1%的高性能器件。HUBLA設備在85攝氏度的氮氣中老化約1500小時后，其初始PCE保持在94%，在85攝氏度和30%相對濕度的空氣中老化1000小時后，其初始PCE保持在88%。
▲ Abstract：
Here we report a living passivation strategy using a hindered urea/thiocarbamate bond Lewis acid–base material (HUBLA), where dynamic covalent bonds with water and heat-activated characteristics can dynamically heal the perovskite to ensure device performance and stability. Upon exposure to moisture or heat, HUBLA generates new agents and further passivates defects in the perovskite. This passivation strategy achieved high-performance devices with a power conversion efficiency (PCE) of 25.1 per cent. HUBLA devices retained 94 per cent of their initial PCE for approximately 1,500 hours of ageing at 85 degrees Celsius in nitrogen and maintained 88 per cent of their initial PCE after 1,000 hours of ageing at 85 degrees Celsius and 30 per cent relative humidity in air.
peri-Fused polyaromatic molecular contacts for perovskite solar cells
鈣鈦礦太陽能電池的聚芳族分子接觸
▲ 作者：Ke Zhao, Qingqing Liu et al.
▲鏈接：
https://www.nature.com/articles/s41586-024-07712-6
▲摘要：
在此，我們報告了一種沒有雜原子取代的環繞稠合多環芳烴核心結構，它比傳統的雜原子取代核心結構具有更好的載流子傳輸和選擇性。
這種核心結構產生了相對化學惰性和結構剛性的分子接觸，可以大大提高鈣鈦礦太陽能電池在效率和耐用性方面的性能。在不同的加速老化測試中，裝置的效率高達26.1%，大大提高了使用壽命。
▲ Abstract：
Here we report a peri-fused polyaromatic core structure without heteroatom substitution that yields superior carrier transport and selectivity over conventional heteroatom-substituted core structures. This core structure produced a relatively chemically inert and structurally rigid molecular contact, which considerably improved the performance of perovskite solar cells in terms of both efficiency and durability. The champion device showed an efficiency up to 26.1% with greatly improved longevity under different accelerated-ageing tests.
化學Chemistry
Hydroamination of alkenes with dinitrogen and titanium polyhydrides
烯烴與二氮和鈦多氫化物的氫胺化反應
▲ 作者：Takanori Shima, Qingde Zhuo et al.
▲鏈接：
https://www.nature.com/articles/s41586-024-07694-5
▲摘要：
在此，我們報告在氫化氚骨架下，簡單烯烴與N2的氫胺化反應，這激活了烯烴和N2，導致選擇性的C-N鍵形成，并提供相應的烷基胺進一步氫化和質子化。
計算研究揭示了N2活化和選擇性C-N鍵形成的關鍵機制細節。這項研究證明了一種通過多核氫化物框架，將N2和簡單烴轉化為含氮有機化合物的策略。
▲ Abstract：
Here we report the hydroamination of simple alkenes with N2 in a trititanium hydride framework, which activates both alkenes and N2, leading to selective C–N bond formation and providing the corresponding alkyl amines on further hydrogenation and protonation. Computational studies reveal key mechanistic details of N2 activation and selective C–N bond formation. This work demonstrates a strategy for the transformation of N2 and simple hydrocarbons into nitrogen-containing organic compounds mediated by a multinuclear hydride framework.
地球科學 Earth Science
Highest ocean heat in four centuries places Great Barrier Reef in danger
四個世紀以來最高的海洋溫度使大堡礁處于危險之中
▲ 作者：Benjamin J. Henley, Helen V. McGregor et al.
▲鏈接：
https://www.nature.com/articles/s41586-024-07672-x
▲摘要：
在此，我們表明在2024年、2017年和2020年（按平均海溫異常降序排列）1月至3月的珊瑚海極端高溫是400年來最溫暖的，超過了我們重建的1900年前最大值的95個百分位不確定性極限。
2016年、2004年和2022年的高溫排名第二，超過了第90個百分位數的限制。氣候模式分析證實，人類對氣候系統的影響是近幾十年來快速變暖的原因。這一歸因，加上最近的海洋極端溫度、1900年后的變暖趨勢和觀測到的大規模珊瑚白化，表明人為氣候變化對大堡礁生態系統的生存威脅現在已經形成。
如果不采取緊急干預措施，標志性的大堡礁將面臨氣溫升高的風險，這將導致近乎每年的珊瑚白化，對生物多樣性和生態系統產生負面影響。如果按照目前的軌跡繼續下去，將進一步威脅到地球上最偉大的自然奇觀之一的生態功能和突出的普遍價值。
▲ Abstract：
Here we show that the January–March Coral Sea heat extremes in 2024, 2017 and 2020 (in order of descending mean SST anomalies) were the warmest in 400 years, exceeding the 95th-percentile uncertainty limit of our reconstructed pre-1900 maximum. The 2016, 2004 and 2022 events were the next warmest, exceeding the 90th-percentile limit. Climate model analysis confirms that human influence on the climate system is responsible for the rapid warming in recent decades. This attribution, together with the recent ocean temperature extremes, post-1900 warming trend and observed mass coral bleaching, shows that the existential threat to the GBR ecosystem from anthropogenic climate change is now realized. Without urgent intervention, the iconic GBR is at risk of experiencing temperatures conducive to near-annual coral bleaching, with negative consequences for biodiversity and ecosystems services. A continuation on the current trajectory would further threaten the ecological function and outstanding universal value of one of Earth’s greatest natural wonders.
Cenozoic history of the tropical marine biodiversity hotspot
熱帶海洋生物多樣性熱點地區的新生代歷史
▲ 作者：Skye Yunshu Tian, Moriaki Yasuhara et al.
▲鏈接：
https://www.nature.com/articles/s41586-024-07617-4
▲摘要：
地球上海洋生物多樣性最高的地區被稱為珊瑚三角或印澳群島（IAA）。在此，我們利用一個全面的化石數據集，通過推斷物種滅絕動態，對IAA的新生代的多樣性歷史進行了高分辨率的重建。
我們發現，自2500萬年前以來，IAA呈現出單向多樣化的趨勢，大致呈對數增長，直到大約260萬年前開始出現多樣性穩定期。
1390萬年前以后，生物多樣性的增長主要受生物多樣性依賴和生境大小的控制，熱應力的緩解也促進了生物多樣性的增長。不同的凈多樣化高峰記錄在大約2500萬年前、2000萬年前、1600萬年前、1200萬年前和500萬年前，這可能與主要的構造事件以及氣候變化有關。
關鍵的生物地理過程對IAA的多樣性產生了深遠的影響，表現在Tethyan后裔的長期衰落和世界性和IAA分類群的長期繁榮。最后，沒有大滅絕和新生代冷卻似乎是使IAA成為地球上海洋生物多樣性最豐富的熱點的關鍵。
▲ Abstract：
The region with the highest marine biodiversity on our planet is known as the Coral Triangle or Indo-Australian Archipelago (IAA). Here we present a high-resolution reconstruction of the Cenozoic diversity history of the IAA by inferring speciation–extinction dynamics using a comprehensive fossil dataset. We found that the IAA has exhibited a unidirectional diversification trend since about 25 million years ago, following a roughly logistic increase until a diversity plateau beginning about 2.6 million years ago. The growth of diversity was primarily controlled by diversity dependency and habitat size, and also facilitated by the alleviation of thermal stress after 13.9 million years ago. Distinct net diversification peaks were recorded at about 25, 20, 16, 12 and 5 million years ago, which were probably related to major tectonic events in addition to climate transitions. Key biogeographic processes had far-reaching effects on the IAA diversity as shown by the long-term waning of the Tethyan descendants versus the waxing of cosmopolitan and IAA taxa. Finally, it seems that the absence of major extinctions and the Cenozoic cooling have been essential in making the IAA the richest marine biodiversity hotspot on Earth.