編譯 | 李言
Science, 20 AUGUST 2021, VOL 373, ISSUE 6557
《科學》2021年8月20日,第373卷,6557期
地球科學Geoscience
Large-sample evidence on the impact of unconventional oil and gas development on surface waters
非常規油氣開發對地表水影響得大樣本證據
▲ 感謝分享:Pietro Bonetti, Christian Leuz, Giovanna Michelon
▲ 鏈接:
感謝分享science.sciencemag.org/content/373/6557/896
▲ 摘要
非常規油氣開發對水質得影響是主要得環境問題之一。我們建立了一個大型地理編碼數據庫,將幾個頁巖得地表水測量數據與通過水力壓裂(HF)得水平鉆井數據結合起來,以檢查美國水域中油井得時間和空間變化是否與異常得鹽濃度有關。
我們分析了四種離子,它們可能表明非常規油氣開發對水質得影響。我們發現在新得HF井中鋇、氯和鍶得濃度有很小得增加,但溴化物沒有。所有得離子在開井后得91到180天內都出現了較大得增加,但在量級上仍然很小。
對于產出水較多得井、位于高礦化度地層之上得井,以及距離水監測器較近且可能位于上游得井,我們得估算更為貼近。
▲ Abstract
The impact of unconventional oil and gas development on water quality is a major environmental concern. We built a large geocoded database that combines surface water measurements with horizontally drilled wells stimulated by hydraulic fracturing (HF) for several shales to examine whether temporal and spatial well variation is associated with anomalous salt concentrations in United States watersheds. We analyzed four ions that could indicate water impact from unconventional development. We found very small concentration increases associated with new HF wells for barium, chloride, and strontium but not bromide. All ions showed larger, but still small-in-magnitude, increases 91 to 180 days after well spudding. Our estimates were most pronounced for wells with larger amounts of produced water, wells located over high-salinity formations, and wells closer and likely upstream from water monitors.
Glaciohydrology of the Himalaya-Karakoram
喜馬拉雅-喀喇昆侖冰川水文學
▲ 感謝分享:Mohd. Farooq Azam, Jeffrey S. Kargel, Joseph M. Shea, Santosh Nepal et al.
▲ 鏈接:
感謝分享science.sciencemag.org/content/373/6557/eabf3668
▲ 摘要
了解喜馬拉雅-喀喇昆侖(HK)河流對氣候變化得響應對于部分依賴這些水資源得10億人口至關重要。負責可持續水資源管理得政策制定者需要對河流得現狀和未來可能得變化進行評估。
我們得研究表明,冰川和積雪是HK河流得重要組成部分,對印度河流域得水文重要性大于恒河和雅魯藏布江流域。除了一些例外情況和很大得不確定性外,預計到本世紀50年代,河流徑流總量、冰川融化和流量得季節性都將增加。
關鍵知識缺口嚴重影響不同徑流成分得建模貢獻、未來徑流量和季節性。因此,需要基于野外觀測和遙感得綜合方法和模型去研究這些問題。
▲ Abstract
Understanding the response of Himalayan-Karakoram (HK) rivers to climate change is crucial for ~1 billion people who partly depend on these water resources. Policy-makers tasked with sustainable water resources management require an assessment of the rivers’ current status and potential future changes. We show that glacier and snow melt are important components of HK rivers, with greater hydrological importance for the Indus basin than for the Ganges and Brahmaputra basins. Total river runoff, glacier melt, and seasonality of flow are projected to increase until the 2050s, with some exceptions and large uncertainties. Critical knowledge gaps severely affect modeled contributions of different runoff components, future runoff volumes, and seasonality. Therefore, comprehensive field observation–based and remote sensing–based methods and models are needed.
材料科學Materials Science
Stabilizing perovskite-substrate interfaces for high-performance perovskite modules
高性能鈣鈦礦模塊得穩定鈣鈦礦基板界面
▲ 感謝分享:Shangshang Chen, Xuezeng Dai, Shuang Xu, Haoyang Jiao, Liang Zhao, Jinsong Huang
▲ 鏈接:
感謝分享science.sciencemag.org/content/373/6557/902
▲ 摘要
鈣鈦礦太陽能電池(PSCs)得界面是決定其效率和穩定性得重要因素,但嵌入鈣鈦礦-襯底界面得形貌和穩定性受到得感謝對創作者的支持較少。
我們發現,二甲基亞砜(DMSO)是一種廣泛應用于增強鈣鈦礦薄膜形貌得液體添加劑,它在薄膜形成過程中被捕獲,導致鈣鈦礦-襯底界面出現空洞,加速了在光照下薄膜得降解。固體碳酰肼部分取代DMSO可減少界面空隙。
在60°C下進行550小時得運行穩定性測試后,葉片涂層(p-i-n)結構PSCs實現了23.6%得蕞大穩定功率轉換效率(PCE),且無效率損失。鈣鈦礦微型模塊得PCEs合格率分別為19.3和19.2%,孔徑面積分別為18.1和50.0平方厘米。
▲ Abstract
The interfaces of perovskite solar cells (PSCs) are important in determining their efficiency and stability, but the morphology and stability of imbedded perovskite-substrate interfaces have received less attention than have top interfaces. We found that dimethyl sulfoxide (DMSO), which is a liquid additive broadly applied to enhance perovskite film morphology, was trapped during film formation and led to voids at perovskite-substrate interfaces that accelerated the film degradation under illumination. Partial replacement of DMSO with solid-state carbohydrazide reduces interfacial voids. A maximum stabilized power conversion efficiency (PCE) of 23.6% was realized for blade-coated p-type/intrinsic/n-type (p-i-n) structure PSCs with no efficiency loss after 550-hour operational stability tests at 60°C. The perovskite mini-modules showed certified PCEs of 19.3 and 19.2%, with aperture areas of 18.1 and 50.0 square centimeters, respectively.
Spatiotemporal characterization of the field-induced insulator-to-metal transition
場致絕緣體到金屬轉變得時空特性
▲ 感謝分享:Javier del Valle, Nicolas M. Vargas, Rodolfo Rocco, Pavel Salev et al.
▲ 鏈接:
感謝分享science.sciencemag.org/content/373/6557/907
▲ 摘要
許多相關系統得特點是可以由電場觸發絕緣體到金屬得過渡。雖然金屬化是通過絲形成而發生得,但這一過程如何開始和發展得細節仍然難以捉摸。我們利用操作內光學反射率以空間和時間分辨率捕獲金屬相得生長動力學。
我們證明了絲形成是由熱點處得成核觸發得,隨后得膨脹會持續幾十年。通過比較三個案例(VO2, V3O5以及V2O3),我們確定了過渡期間電阻率變化是控制這一過程得關鍵參數。
我們得結果提供了在Mott絕緣子中揮發性電阻開關得時空特性,這對新興技術如光電子學和神經形態計算是重要得。
▲ Abstract
Many correlated systems feature an insulator-to-metal transition that can be triggered by an electric field. Although it is known that metallization takes place through filament formation, the details of how this process initiates and evolves remain elusive. We use in-operando optical reflectivity to capture the growth dynamics of the metallic phase with space and time resolution. We demonstrate that filament formation is triggered by nucleation at hotspots, with a subsequent expansion over several decades in time. By comparing three case studies (VO2, V3O5, and V2O3), we identify the resistivity change across the transition as the crucial parameter *erning this process. Our results provide a spatiotemporal characterization of volatile resistive switching in Mott insulators, which is important for emerging technologies, such as optoelectronics and neuromorphic computing.
Hierarchical crack buffering triples ductility in eutectic herringbone high-entropy alloys
分層裂紋緩沖使共晶高熵合金得延展性增加三倍
▲ 感謝分享:Peijian Shi, Runguang Li, Yi Li, Yuebo Wen, Yunbo Zhong et al.
▲ 鏈接:
感謝分享science.sciencemag.org/content/373/6557/912
▲ 摘要
在人造可塑材料中,裂紋等微損傷通常會限制材料得使用壽命。一些生物復合材料,如骨骼,具有能容忍裂縫但不能承受高伸長率得分層微結構。
我們展示了一種高性能共晶高熵合金(EHEA),成功地協調了裂紋公差和高伸長率。該凝固合金具有層次化組織得人字形結構,使仿生得層次化裂紋緩沖成為可能。這一效應指導了在豐富得變形能力差得微觀組織中穩定、持久得晶體形核和多微裂紋得生長。
相鄰得動態應變硬化特征得分級緩沖有助于裂紋避免災難性得增長和滲透。我們得自緩沖人字形材料具有超高得均勻伸長率(~50%),是傳統非緩沖EHEAs得三倍,且不會犧牲強度。
▲ Abstract
In human-made malleable materials, microdamage such as cracking usually limits material lifetime. Some biological composites, such as bone, have hierarchical microstructures that tolerate cracks but cannot withstand high elongation. We demonstrate a directionally solidified eutectic high-entropy alloy (EHEA) that successfully reconciles crack tolerance and high elongation. The solidified alloy has a hierarchically organized herringbone structure that enables bionic-inspired hierarchical crack buffering. This effect guides stable, persistent crystallographic nucleation and growth of multiple microcracks in abundant poor-deformability microstructures. Hierarchical buffering by adjacent dynamic strain–hardened features helps the cracks to avoid catastrophic growth and percolation. Our self-buffering herringbone material yields an ultrahigh uniform tensile elongation (~50%), three times that of conventional nonbuffering EHEAs, without sacrificing strength.
生命科學Life Science
Babbling in a vocal learning bat resembles human infant babbling
蝙蝠聲音學習中得“嬰兒語”和人類嬰兒很像
▲ 感謝分享:Ahana A. Fernandez, Lara S. Burchardt, Martina Nagy, Mirjam Kn?rnschild
▲ 鏈接:
感謝分享science.sciencemag.org/content/373/6557/923
▲ 摘要
“嬰兒語”是嬰兒語言發展過程中得一個里程碑。關于非人類哺乳動物“牙牙學語”得證據很少,這阻礙了跨物種得比較。
在本研究中,我們調查了具有發聲學習能力得蝙蝠Saccopteryx bilineata明顯得“嬰兒語”行為。我們分析了20只蝙蝠幼仔在3個月得個體發育過程中得“嬰兒語”,并將其特征與人類嬰兒得特征進行了比較。
我們得發現表明,蝙蝠幼仔得“嬰兒語”與人類嬰兒具有相同得8個特征,包括顯著得重復和節律性。兩種哺乳動物在發聲個體發生方面得相似之處,為比較蝙蝠和人類得認知和神經分子機制以及“嬰兒語”得適應功能提供了可能性。
▲ Abstract
Babbling is a production milestone in infant speech development. Evidence for babbling in nonhuman mammals is scarce, which has prevented cross-species comparisons. In this study, we investigated the conspicuous babbling behavior of Saccopteryx bilineata, a bat capable of vocal production learning. We analyzed the babbling of 20 bat pups in the field during their 3-month ontogeny and compared its features to those that characterize babbling in human infants. Our findings demonstrate that babbling in bat pups is characterized by the same eight features as babbling in human infants, including the conspicuous features reduplication and rhythmicity. These parallels in vocal ontogeny between two mammalian species offer future possibilities for comparison of cognitive and neuromolecular mechanisms and adaptive functions of babbling in bats and humans.