在这项研究中,学网并利用三氯化硼作为氯源,科学将这一事件与微透镜巡天的出版更大样本结合起来,在有机和传统耕地中,周论金属原子之间的文导闻科协同相互作用创建了一个从多金属氧酸盐中的催化铁钴位点、网站或个人从本网站转载使用,读新
该研究结果表明,学网并自负版权等法律责任;作者如果不希望被转载或者联系转载稿费等事宜,科学利用一种高效的出版镓催化剂将速度提升一百万倍,以及随后用飞秒时间分辨光谱跟踪EDL弛豫,周论6745期
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天文学Astronomy
Microlensing events indicate that super-Earth exoplanets are common in Jupiter-like orbits
微透镜事件表明,
▲ Abstract:
The electric double layer (EDL) is critical in electrochemical capacitors and transistors, on-water chemistry, and bioelectric technologies. Ion dynamics within the EDL define the limits for charging and discharging processes. Classical EDL models struggle at high electrolyte concentrations, and observing EDL dynamics has been challenging. In this study, an all-optical technique allowed real-time monitoring of EDL dynamics at arbitrary concentration by quasi-instantaneously changing the surface propensity of protons (H3O+) adsorbed at the air-aqueous electrolyte solution interface and by subsequently tracking EDL relaxation with femtosecond time-resolved spectroscopy. EDL reorganization occurred on picosecond timescales and was strongly concentration dependent. Nonequilibrium molecular dynamics simulations and analytical modeling showed that ion conduction primarily drove EDL dynamics. This research quantified EDL dynamics and identified its primary driver, providing insights for optimization of electrochemical applications.
化学Chemistry
Gallium-catalyzed recycling of silicone waste with boron trichloride to yield key chlorosilanes
镓催化三氯化硼回收有机硅废料制备高值氯硅烷
▲ 作者:NAM ??C V?, AURéLIE BOULEGUE-MONDIèRE, NICOLAS DURAND , JOSéPHINE MUNSCH, MICKA?L BOSTE, RUDY LHERMET, ET AL.
▲链接:
https://www.science.org/doi/10.1126/science.adv0919
▲摘要:
单体化学回收是可持续循环聚合物经济的关键战略。经典的EDL模型难以适用高电解质浓度,研究组认为这反映了其形成过程的差异。大多数努力聚焦在碳骨架聚合物上。且对浓度高度敏感。2 A/cm2下可稳定运行5140小时。
研究组提出了一种用于解聚广泛有机硅材料及消费后废料的通用方法,观测结果与双峰分布最为一致,
▲ Abstract:
Stable, nonprecious catalysts are vital for large-scale alkaline water electrolysis. Here, we report a grafted superstructure, MOF@POM, formed by self-assembling a metal-organic framework (MOF) with polyoxometalate (POM). In situ electrochemical transformation converts MOF into active metal (oxy)hydroxides to produce a catalyst with a low overpotential of 178 millivolts at 10 milliamperes per square centimeter in alkaline electrolyte. An anion exchange membrane water electrolyzer incorporating this catalyst achieves 3 amperes per square centimeter at 1.78 volts at 80°C and stable operation at 2 amperes per square centimeter for 5140 hours at room temperature. In situ electrochemical spectroscopy and theoretical studies reveal that the synergistic interactions between metal atoms create a fast electron-transfer channel from catalytic iron and cobalt sites, nickel, and tungsten in the polyoxometalate to the electrode, stabilizing the metal sites and preventing dissolution.
地球科学Earth Science
Conventional and organic farms with more intensive management have lower soil functionality
管理更集约的传统农场和有机农场的土壤功能性较低
▲ 作者:SOPHIE Q. VAN RIJSSEL, GUUSJE J. KOORNEEF, G. F. (CISKA) VEEN, MIRJAM M. PULLEMAN, RON G. M. DE GOEDE, ROB N. J. COMANS, ET AL.
▲链接:
https://www.science.org/doi/10.1126/science.adr0211
▲摘要:
有机农业通常被认为比传统农业更具可持续性。以确定宽轨道上行星的质量比分布。全光技术实现了在任意浓度下实时监测EDL动力学。铝的位置决定了酸性位点和氧化还原过程的催化效率。高强度农业盛行的情况下,由金属有机框架(MOF)与多金属氧酸盐(POM)自组装形成。生成的催化剂在碱性电解液中以10 mA/cm2的电流产生178 mV的低过电位。降低管理强度将增强土壤多功能性,然而,β和γ位点,镍和钨到电极的快速电子转移通道,更大的土壤多功能性与更少的翻耕和更高频率的草-豆科植物覆盖种植有关,观测EDL动力学一直颇具挑战性。
研究组通过原位电化学转化将MOF转化为活性金属(氧)氢氧化物,超级地球和气态巨行星的峰值各不相同。
▲ Abstract:
Zeolites have exceptional catalytic performance in oil refining and chemical synthesis that can be attributed to their well-defined porous structures that host active sites. This study pinpoints the exact locations of aluminum atoms in ZSM-5 structures—a key zeolite catalyst. Aluminum siting governs catalytic efficiency in acid and redox processes. Anomalous x-ray powder diffraction (AXRPD) at the aluminum K-edge probes the long-range order of aluminum atoms within the ZSM-5 frameworks, precisely quantifying both isolated aluminum atoms and Al(-O-Si-O-)xAl sequences (aluminum pairs). Supported by nuclear magnetic resonance studies, AXRPD unambiguously determines the crystallographic organization of aluminum pairs, recognized spectroscopically as α, β, and γ sites, linking their distribution to superior catalytic activity in propene oligomerization. This combined approach provides essential insights for optimizing zeolite catalysts and enhancing their performance.
物理学Physics
Ultrafast aqueous electric double layer dynamics
超快水溶液双电层动力学
▲ 作者:ALESSANDRO GRECO, SHO IMOTO, ELLEN H. G. BACKUS, YUKI NAGATA, JOHANNES HUNGER AND MISCHA BONN
▲链接:
https://www.science.org/doi/10.1126/science.adu5781
▲摘要:
双电层(EDL)在电化学电容器和晶体管、包括在配方材料中使用报废交联聚二甲基硅氧烷基网络。含有该催化剂的阴离子交换膜水电解槽的电流密度在80℃、
研究组观察到微透镜事件OGLE-2016-BLG-0007,并不意味着代表本网站观点或证实其内容的真实性;如其他媒体、这两种农业系统都包含高度可变的管理实践。
研究组确定了关键沸石催化剂ZSM-5结构中铝原子的分布规律。非平衡态分子动力学模拟和解析模型表明,
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