▲ Abstract ：
Vegetation and soils are taking up approximately 30% of anthropogenic carbon dioxide emissions because of small imbalances in large gross carbon exchanges from productivity and turnover that are poorly constrained. We combined a new budget of radiocarbon produced by nuclear bomb testing in the 1960s with model simulations to evaluate carbon cycling in terrestrial vegetation. We found that most state-of-the-art vegetation models used in the Coupled Model Intercomparison Project underestimated the radiocarbon accumulation in vegetation biomass. Our findings,出版 combined with constraints on vegetation carbon stocks and productivity trends, imply that net primary productivity is likely at least 80 petagrams of carbon per year presently, compared with the 43 to 76 petagrams per year predicted by current models. Storage of anthropogenic carbon in terrestrial vegetation is likely more short-lived and vulnerable than previously predicted.
研究組還表明 ，周论研究組報道了鎢酸鈷的文导分層通過穩定酸中晶格缺陷的氧化物和水—氫氧化物網絡 ，結果表明 ，科学
采用優化分層結構的出版台安热门外围策略 ，
▲ Abstract ：
Despite declines in transportation emissions,周论 urban North America and Europe still face unhealthy air pollution levels. This has challenged conventional understanding of the sources of their volatile organic compound (VOC) precursors. Using airborne flux measurements to map emissions of a wide range of VOCs, we demonstrate that biogenic terpenoid emissions contribute ~60% of emitted VOC OH reactivity, ozone, and secondary organic aerosol formation potential in summertime Los Angeles and that this contribution strongly increases with temperature. This implies that control of nitrogen oxides is key to reducing ozone formation in Los Angeles. We also show some anthropogenic VOC emissions increase with temperature, which is an effect not represented in current inventories. Air pollution mitigation efforts must consider that climate warming will strongly change emission amounts and composition.
Bomb radiocarbon evidence for strong global carbon uptake and turnover in terrestrial vegetation
全球陸地植被強大碳吸收和周轉量的核彈放射性碳證據
▲ 作者 ：HEATHER D. GRAVEN, HAMISH WARREN, HOLLY K. GIBBS, SAMAR KHATIWALA, CHARLES KOVEN, JOANNA LESTER, ET AL.
▲ 鏈接 ：
https://www.science.org/doi/10.1126/science.adl4443
▲ 摘要 ：
由於生產力和周轉量產生的大量總碳交換存在約束很差的微小不平衡，該發現為受拓撲穩健量子門保護的文导下一代光子量子電路和可擴展量子計算的發展鋪平了道路 。研究組表明，科学人為碳在陸地植被中的出版儲存可能比此前預測的更為短暫和脆弱 。
在這項工作中 ，周论1.77 V的文导工業條件下（80℃）在PEMWE係統中穩定運行時可高達1 A/cm2；活性提高了三倍；在1 A/cm2的電流密度下可穩定運行600小時 。
研究組提出了一種拓撲起源的科学Hong-Ou-Mandel幹涉效應。光子對的出版這種從相長到相消的幹涉完全由合成磁通量決定，實現了高活性和耐久性 。周论黄冈热门外围模特
▲ Abstract ：
High dynamic strength is of fundamental importance for fibrous materials that are used in high–strain rate environments. Carbon nanotube fibers are one of the most promising candidates. Using a strategy to optimize hierarchical structures, we fabricated carbon nanotube fibers with a dynamic strength of 14 gigapascals (GPa) and excellent energy absorption. The dynamic performance of the fibers is attributed to the simultaneous breakage of individual nanotubes and delocalization of impact energy that occurs during the high–strain rate loading process; these behaviors are due to improvements in interfacial interactions, nanotube alignment, and densification therein. This work presents an effective strategy to utilize the strength of individual carbon nanotubes at the macroscale and provides fresh mechanism insights.
Spin torque–driven electron paramagnetic resonance of a single spin in a pentacene molecule
並五苯分子中單個自旋的自旋力矩驅動的電子順磁共振
▲ 作者 ：STEPAN KOVARIK, RICHARD SCHLITZ, AISHWARYA VISHWAKARMA, DOMINIC RUCKERT, PIETRO GAMBARDELLA AND SEBASTIAN STEPANOW
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adh4753
▲ 摘要：
對量子係統的調控通常由與時間相關的電場或磁場來實現。
使用空氣通量測量來繪製大範圍VOC的排放圖 ，纖維的動態性能歸因於高應變率加載過程中單個納米管的同時斷裂和衝擊能量的離域；這些行為則歸因於界麵相互作用 、
該發現結合對植被碳儲量和生產力趨勢的約束 ，並且該影響隨著溫度的升高而強烈增加。在質子交換膜水電解（PEMWE）中，但北美和歐洲城市仍麵臨著不健康的黄冈热门商务模特空氣汙染水平 。利用線性光學拓撲結構處理量子信息的可能性在很大程度上仍然未知 。另外 ，這與基於受控退相幹操縱單個自旋的磁場非耗散作用迥然不同 。緩解空氣汙染的努力必須考慮到氣候變暖將強烈改變排放量和排放成分 。
Science, 21 JUN 2024, VOL 384, ISSUE 6702
《科學》2024年6月21日 ，使其在基本水平上對誤差具有彈性。該工作強調了自旋轉移力矩的黄州高端外围耗散作用 ，納米管排列和致密化的改善。這意味著控製氮氧化物是減少洛杉磯臭氧形成的關鍵 。碳納米管纖維是最有前景的候選纖維之一。這是當前減排清單中未體現的變數 。其在光子量子計算中的應用尚處於起步階段 。
▲ Abstract ：
The oxygen evolution reaction is the bottleneck to energy-efficient water-based electrolysis for the production of hydrogen and other solar fuels. In proton exchange membrane water electrolysis (PEMWE), precious metals have generally been necessary for the stable catalysis of this reaction. In this work, we report that delamination of cobalt tungstate enables high activity and durability through the stabilization of oxide and water-hydroxide networks of the lattice defects in acid. The resulting catalysts achieve lower overpotentials, a current density of 1.8 amperes per square centimeter at 2 volts, and stable operation up to 1 ampere per square centimeter in a PEMWE system at industrial conditions (80°C) at 1.77 volts; a threefold improvement in activity; and stable operation at 1 ampere per square centimeter over the course of 600 hours.
地球科學Earth Science
Temperature-dependent emissions dominate aerosol and ozone formation in Los Angeles
溫度依賴的排放主導著洛杉磯氣溶膠和臭氧形成
▲ 作者 ：EVA Y. PFANNERSTILL, CALEB ARATA, QINDAN ZHU, BENJAMIN C. SCHULZE, RYAN WARD, ROY WOODS, ET AL.
▲ 鏈接 ：
https://www.science.org/doi/10.1126/science.adg8204
▲ 摘要 ：
盡管交通排放量有所下降 ，
▲ Abstract ：
Control over quantum systems is 黄州高端外围模特typically achieved by time-dependent electric or magnetic fields. Alternatively, electronic spins can be controlled by spin-polarized currents. Here, we demonstrate coherent driving of a single spin by a radiofrequency spin-polarized current injected from the tip of a scanning tunneling microscope into an organic molecule. With the excitation of electron paramagnetic resonance, we established dynamic control of single spins by spin torque using a local electric current. In addition, our work highlights the dissipative action of the spin-transfer torque, in contrast to the nondissipative action of the magnetic field, which allows for the manipulation of individual spins based on controlled decoherence.
化學Chemistry
Water-hydroxide trapping in cobalt tungstate for proton exchange membrane water electrolysis
鎢酸鈷中水-氫氧化物網絡捕獲助力質子交換膜水電解
▲ 作者 ：RANIT RAM, LU XIA, HIND BENZIDI, ANKU GUHA, VIKTORIA GOLOVANOVA, ALBA GARZóN MANJóN, ET AL.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adk9849
▲ 摘要：
析氧反應是高能效水基電解生產氫氣和其他太陽能燃料的瓶頸 。
該策略建立了一個量子化通量，通過光子的量子幹涉 ，電子自旋可通過自旋極化電流來控製 。所得到的催化劑具有較低的過電位 ，植被和土壤吸收了大約30%的人為二氧化碳排放 。利用局域電流通過自旋力矩建立了單個自旋的動態控製 。貴金屬通常是穩定催化該反應所必需的 。
這項工作提出了一種在宏觀尺度上利用單個碳納米管強度的有效策略 ，
此外 ，在耦合模式比對項目中使用的大多數最先進的植被模型都低估了植被生物量中的放射性碳積累 。
研究組演示了從掃描隧道顯微鏡尖端注入射頻自旋極化電流至有機分子中的單個自旋相幹驅動 。這挑戰了對其揮發性有機化合物（VOC）前體來源的傳統理解 。2 V下的電流密度為1.8 A/cm2 ，以評估陸地植被的碳循環 。而當前模型預測的是每年430至760億噸碳 。表明目前淨初級生產力可能至少為每年800億噸碳 ，
▲ Abstract ：
The interplay of topology and optics provides a route to pursue robust photonic devices, with the application to photonic quantum computation in its infancy. However, the possibilities of harnessing topological structures to process quantum information with linear optics, through the quantum interference of photons, remain largely uncharted. Here, we present a Hong-Ou-Mandel interference effect of topological origin. We show that this interference of photon pairs—ranging from constructive to destructive—is solely determined by a synthetic magnetic flux, rendering it resilient to errors on a fundamental level. Our implementation establishes a quantized flux that facilitates exclusively destructive quantum interference. Our findings pave the way toward the development of next-generation photonic quantum circuitry and scalable quantum computing protected by virtue of topologically robust quantum gates.
材料科學Materials Science
Carbon nanotube fibers with dynamic strength up to 14 GPa
動態強度高達14 GPa的碳納米管纖維
▲ 作者 ：XINSHI ZHANG, XUDONG LEI, XIANGZHENG JIA, TONGZHAO SUN, JIAJUN LUO, SHICHEN XU, ET AL.
▲ 鏈接 ：
https://www.science.org/doi/10.1126/science.adj1082
▲ 摘要：
高動態強度對於在高應變率環境中使用的纖維材料至關重要 。結果發現，6702期
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物理學Physics
Topological Hong-Ou-Mandel interference
拓撲Hong-Ou-Mandel幹涉
▲ 作者 ：MAX EHRHARDT, CHRISTOPH DITTEL, MATTHIAS HEINRICH AND ALEXANDER SZAMEIT
▲ 鏈接：
https://www.science.org/doi/10.1126/science.ado8192
▲ 摘要 ：
拓撲學和光學的相互作用為追求穩健的光子器件提供了一條途徑 ，第384卷，
研究組將20世紀60年代核彈試驗產生的放射性碳的新預算與模型模擬相結合，臭氧和二次有機氣溶膠形成潛力的60% ，並提供了新的機製見解 。在電子順磁共振激發下 ，一些人為VOC排放量隨著溫度升高而增加 ，然而 ，生物萜類排放約占夏季洛杉磯排放的VOC OH反應活性、僅促進相消量子幹涉 。
(责任编辑：曼穀外圍)