原文地址：http://news.sciencenet.cn/htmlnews/2023/12/514826.shtm
編譯 | 李言
Nature, 22 DEC 2023, Volume 382 Issue 6677
《自然》, 2023年12月22日，第382卷，6677期
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材料科學Materials Science
Biomimetic, knittable aerogel fiber for thermal insulation textile
用于保溫紡織品的仿生針織氣凝膠纖維
▲ 作者：MINGRUI WU, ZIYU SHAO et al.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adj8013
▲ 摘要：
氣凝膠被認為是一種理想的隔熱材料。然而，由于易碎性和交叉口的可加工性，它們在紡織品中的應用受到了很大的限制。我們通過在氣凝膠纖維中包裹一層模仿北極熊毛發核—殼結構的可拉伸層來克服這些問題。
盡管其內部孔隙率超過90%，但我們的纖維可拉伸至1000%的應變，與傳統的氣凝膠纖維相比，有了很大的提高。用我們的纖維編織的毛衣厚度只有羽絨制品的五分之一，但性能卻相差無幾。我們這種纖維的策略為開發多功能氣凝膠纖維和紡織品提供了豐富的可能性。
▲ Abstract：
Aerogels have been considered as an ideal material for thermal insulation. Unfortunately, their application in textiles is greatly limited by their fragility and poor processability. We overcame these issues by encapsulating the aerogel fiber with a stretchable layer, mimicking the core-shell structure of polar bear hair. Despite its high internal porosity over 90%, our fiber is stretchable up to 1000% strain, which is greatly improved compared with that of traditional aerogel fibers (~2% strain). In addition to its washability and dyeability, our fiber is mechanically robust, retaining its stable thermal insulation property after 10,000 stretching cycles (100% strain). A sweater knitted with our fiber was only one-fifth as thick as down, with similar performance. Our strategy for this fiber provides rich possibilities for developing multifunctional aerogel fibers and textiles.
信息技術Information Technology
Are cryptocurrencies currencies? Bitcoin as legal tender in El Salvador
加密貨幣是貨幣嗎？比特幣在薩爾瓦多成為法定貨幣
▲ 作者：FERNANDO ALVAREZ, DAVID ARGENTE et al.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.add2844
▲ 摘要：
貨幣的基本特征是一種交換媒介。我們的研究探討了作為第一個將比特幣定為法定貨幣的國家，加密貨幣在薩爾瓦多日常交易中使用的潛力。政府的大力推動促進了“Chivo錢包”的出現，這是一種與中央銀行數字貨幣（CBDCs）共享功能的數字錢包，可以用來交易比特幣和美元。
通過對全國1800個家庭的面對面調查和包含所有Chivo錢包交易的區塊鏈數據，我們記錄了數字支付和比特幣使用率低且不斷下降的模式。
隱私和安全問題是主要的使用障礙，這涉及到以匿名為核心的加密貨幣和CBDCs的政策爭議。此外，我們估計了Chivo錢包的使用成本和使用者之間的關系。
▲ Abstract：
A currency’s essential feature is to be a medium of exchange. This study explores the potential of cryptocurrencies to be used in daily transactions in El Salvador, the first country to make bitcoin legal tender. The government’s “big push” introduced “Chivo Wallet,” a digital wallet sharing features with Central Bank Digital Currencies (CBDCs), with perks to use it for trading bitcoins and US dollars. Through a nationally representative, face-to-face survey of 1800 households and blockchain data encompassing all Chivo Wallet transactions, we document a pattern of low and decreasing usage of digital payments and bitcoin. Privacy and security concerns are key adoption barriers, which speaks to a policy debate on crypto and CBDCs with anonymity at its core. Additionally, we estimate Chivo Wallet’s adoption cost and complementarities among adopters.
化學Chemistry
Autonomous, multiproperty-driven molecular discovery: From predictions to measurements and back
多屬性驅動的分子自主發現：從預測到測算的回顧
▲ 作者：BRENT A. KOSCHER, RICHARD B. CANTY et al.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adi1407
▲ 摘要：
吸收波長、親脂性和光氧化穩定性，我們展示了染料類分子的兩個案例研究。在第一項研究中，該平臺通過三次分子設計—制造—測試—分析循環的自動迭代實驗實現了294個未報道的分子，同時探索了4種很少報道的支架的結構—功能空間。
在每次迭代中，引導探索的性質預測模型通過多步合成和多種反應，學習了不同支架衍生物的結構—性質空間。第二項研究利用在探索化學空間和以往研究的分子上訓練的性質模型，在輕度探索的結構—性質空間中發現了9個表現最好的分子。
▲ Abstract：
We demonstrated two case studies on dye-like molecules, targeting absorption wavelength, lipophilicity, and photooxidative stability. In the first study, the platform experimentally realized 294 unreported molecules across three automatic iterations of molecular design-make-test-analyze cycles while exploring the structure-function space of four rarely reported scaffolds. In each iteration, the property prediction models that guided exploration learned the structure-property space of diverse scaffold derivatives, which were realized with multistep syntheses and a variety of reactions. The second study exploited property models trained on the explored chemical space and previously reported molecules to discover nine top-performing molecules within a lightly explored structure-property space.
社會學Sociology
Highlighting health consequences of racial disparities sparks support for action
強調種族差異對健康的影響，可以激發對行動的支持
▲ 作者：RIANA M. BROWN, PIA DIETZE et al.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adh4262
▲ 摘要：
種族差異在美國生活的許多重要領域顯現，包括就業、健康和人際交往。例如，三分之一的黑人兒童生活在貧困中（白人兒童則是九分之一），而且，美國黑人的平均壽命比白人少四年。
哪種差距更有可能激發減少差距的努力？我們發現，相對于經濟，強調與健康相關結果的差異會刺激更多的社交媒體參與和對緩解差異政策的支持。
此外，與基于經濟或歸屬的差異相比，閱讀有關種族健康差異的文章會引起對行動的更多支持。出現這種情況的部分原因是，人們認為健康上的差距違反了神圣的道德價值觀，這加劇了人們不公正的感覺。這項研究闡明了種族不平等的哪些表現形式最有可能促使美國人采取行動。
▲ Abstract：
Racial disparities arise across many vital areas of American life, including employment, health, and interpersonal treatment. For example, one in three Black children lives in poverty (versus one in nine white children), and, on average, Black Americans live four fewer years compared with white Americans. Which disparity is more likely to spark reduction efforts We find that highlighting disparities in health-related (versus economic) outcomes spurs greater social media engagement and support for disparity-mitigating policy. Further, reading about racial health disparities elicits greater support for action (e.g., protesting) compared with economic- or belonging-based disparities. This occurs in part because people view health disparities as violating morally sacred values, which enhances perceived injustice. This work elucidates which manifestations of racial inequality are most likely to prompt Americans to action.
地球科學Earth Science
Genomic evidence for West Antarctic Ice Sheet collapse during the Last Interglacial
末次間冰期南極西部冰蓋崩塌的基因組證據
▲ 作者：SALLY C. Y. LAU, NERIDA G. WILSON et al.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.ade0664
▲ 摘要：
在未來的氣候軌跡下，以海洋為基礎的南極西部冰蓋（WAIS）被認為很容易發生不可逆轉的崩塌，其臨界點可能在聯合國《巴黎協定》規定的1.5°C至2°C的減緩變暖情景范圍內。
對過去類似溫暖氣候期間冰損失的了解可以解決這種不確定性，例如末次間冰期，當時全球海平面比今天高5至10米，全球平均氣溫比工業化前水平高0.5°至1.5°C。
利用一組環—南極章魚的全基因組單核苷酸多態性，我們發現只有在WAIS完全崩潰的情況下，才有可能出現持久性、歷史性的基因流信號。我們的研究結果提供了首個經驗證據，表明即使在嚴格的氣候減緩情景下，也可能達到WAIS損失的臨界點。
▲ Abstract：
The marine-based West Antarctic Ice Sheet (WAIS) is considered vulnerable to irreversible collapse under future climate trajectories, and its tipping point may lie within the mitigated warming scenarios of 1.5° to 2°C of the United Nations Paris Agreement. Knowledge of ice loss during similarly warm past climates could resolve this uncertainty, including the Last Interglacial when global sea levels were 5 to 10 meters higher than today and global average temperatures were 0.5° to 1.5°C warmer than preindustrial levels. Using a panel of genome-wide, single-nucleotide polymorphisms of a circum-Antarctic octopus, we show persistent, historic signals of gene flow only possible with complete WAIS collapse. Our results provide the first empirical evidence that the tipping point of WAIS loss could be reached even under stringent climate mitigation scenarios.
Learning skillful medium-range global weather forecasting
熟練的全球中期天氣預報
▲ 作者：REMI LAM, ALVARO SANCHEZ-GONZALEZ et al.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adi2336
▲ 摘要：
在這里，我們介紹GraphCast，這是一種基于機器學習、直接從再分析數據中訓練的方法。它可以在一分鐘內以0.25°的分辨率預測未來10天全球數百個天氣變量。
在1380個驗證目標中，GraphCast在90%的驗證目標中顯著優于目前最精確的操作確定性系統，它可以進行更高質量的嚴重事件預測，包括熱帶氣旋跟蹤、大氣河和極端溫度。GraphCast的出現是準確和高效天氣預報的重要進步，有助于實現機器學習對復雜動態系統建模的愿景。
▲ Abstract：