Independent of traditional approach of satellite altimeter calibration, the feasibility of altimeter validation using tide gauge located on solitary island at open sea (TGSI) and deep-ocean bottom pressure recorder (D...Independent of traditional approach of satellite altimeter calibration, the feasibility of altimeter validation using tide gauge located on solitary island at open sea (TGSI) and deep-ocean bottom pressure recorder (DBPR) separately is initially studied. Bias of Jason-3 sea surface height (SSH) and relative SSH bias (Δbias) between Jason-2 and Jason-3 is calculated using the data of tide gauge on Harvest oil platform, tide gauge No. 1890000 and DBPR No. 21419. The standard deviations of calculated SSH bias sequence are 3.98 cm, 2.87 cm and 8.61 cm respectively, and Δbias (Jason-3—Jason-2) is -3.62± 2.17 cm , -2.58±1.97 cm and -2.60±1.30 cm respectively. Comparing to the results reported by international calibration sites, the results show that Jason-3 SSH is 3.0 cm lower than that of Jason-2, the selected DBPR is appropriate to the calculation of relative SSH bias between Jason-2 and Jason-3, but it is not suitable for calibration or validation of single satellite, TGSI is appropriate to both.展开更多
Acidic water splitting,essential for sustainable hydrogen production,is limited by the sluggish oxygen evolution reaction(OER).This study presents a series of iridium-based sub-nanocluster electrocatalysts supported o...Acidic water splitting,essential for sustainable hydrogen production,is limited by the sluggish oxygen evolution reaction(OER).This study presents a series of iridium-based sub-nanocluster electrocatalysts supported on a porous carbon matrix(CBC-Ir-T,T=300,400,and 500°C)for efficient overall water splitting.Impressively,CBC-Ir-400,with an ultralow Ir loading of 1.4μg·cm^(−2),exhibits exceptional bifunctional activity,achieving 10 mA·cm^(−2) at overpotentials of only 240 mV for OER and 30 mV for hydrogen evolution reaction(HER).In practical acidic water splitting,it delivers a cell voltage of 1.53 V at 10 mA·cm^(−2),outperforming the commercial Ir/C||Pt/C system.Comprehensive characterization reveals that the cucurbit[6]uril-derived porous carbon matrix,rich in defects and high specific surface area,promotes the formation of uniformly dispersed sub-nano Ir clusters.This optimizes the iridium electronic structure for enhanced intermediate adsorption,while strong electrical coupling with carbon support boosts charge transfer and mass transport.This synergy drives its superior performance.Our findings offer a scalable strategy for designing high-performance,ultralow-loading iridium sub-nanocluster catalysts,paving the way for cost-effective and sustainable hydrogen production via water electrolysis.展开更多
基金National Natural Science Foundation of China(No.41774018,41674082)Foundation of State Key Laboratory of Geo-information Engineering(No.SKLGIE2018-ZZ-4)。
文摘Independent of traditional approach of satellite altimeter calibration, the feasibility of altimeter validation using tide gauge located on solitary island at open sea (TGSI) and deep-ocean bottom pressure recorder (DBPR) separately is initially studied. Bias of Jason-3 sea surface height (SSH) and relative SSH bias (Δbias) between Jason-2 and Jason-3 is calculated using the data of tide gauge on Harvest oil platform, tide gauge No. 1890000 and DBPR No. 21419. The standard deviations of calculated SSH bias sequence are 3.98 cm, 2.87 cm and 8.61 cm respectively, and Δbias (Jason-3—Jason-2) is -3.62± 2.17 cm , -2.58±1.97 cm and -2.60±1.30 cm respectively. Comparing to the results reported by international calibration sites, the results show that Jason-3 SSH is 3.0 cm lower than that of Jason-2, the selected DBPR is appropriate to the calculation of relative SSH bias between Jason-2 and Jason-3, but it is not suitable for calibration or validation of single satellite, TGSI is appropriate to both.
基金the financial support from the National Key R&D Program of China(Nos.2023YFA507101 and 2022YFA1503900)the National Natural Science Foundation of China(Nos.22471270,22033008,and 22220102005).
文摘Acidic water splitting,essential for sustainable hydrogen production,is limited by the sluggish oxygen evolution reaction(OER).This study presents a series of iridium-based sub-nanocluster electrocatalysts supported on a porous carbon matrix(CBC-Ir-T,T=300,400,and 500°C)for efficient overall water splitting.Impressively,CBC-Ir-400,with an ultralow Ir loading of 1.4μg·cm^(−2),exhibits exceptional bifunctional activity,achieving 10 mA·cm^(−2) at overpotentials of only 240 mV for OER and 30 mV for hydrogen evolution reaction(HER).In practical acidic water splitting,it delivers a cell voltage of 1.53 V at 10 mA·cm^(−2),outperforming the commercial Ir/C||Pt/C system.Comprehensive characterization reveals that the cucurbit[6]uril-derived porous carbon matrix,rich in defects and high specific surface area,promotes the formation of uniformly dispersed sub-nano Ir clusters.This optimizes the iridium electronic structure for enhanced intermediate adsorption,while strong electrical coupling with carbon support boosts charge transfer and mass transport.This synergy drives its superior performance.Our findings offer a scalable strategy for designing high-performance,ultralow-loading iridium sub-nanocluster catalysts,paving the way for cost-effective and sustainable hydrogen production via water electrolysis.
