Developing highly efficient platinum‐group‐metal‐free electrocatalysts towards hydrogen oxidation reaction(HOR)under alkaline electrolyte is critical for the development of alkaline exchange member fuel cells.Herei...Developing highly efficient platinum‐group‐metal‐free electrocatalysts towards hydrogen oxidation reaction(HOR)under alkaline electrolyte is critical for the development of alkaline exchange member fuel cells.Herein,we reported the synthesis of boron doped Ni electrocatalyst(B‐Ni/C)and its remarkable alkaline HOR performance,with a 10‐fold mass activity enhancement compared with that of undoped Ni catalyst.Experimental results and density functional theory calculations indicate the d‐p hybridization between the p orbital of B and the d orbital of Ni via B‐doping could lead to promoted OH adsorption and optimized hydrogen binding energy on Ni surface,which together with the reduced formation energy of water species,contributes to the enhanced HOR performance under alkaline electrolyte.展开更多
利用HPLC/DAD-ESI(-)MS联用技术对植物长萼小连翘(Hypericum erectum subsp. longisepalum L. H. Wu et D. P. Yang)中主要化学成分进行了分离分析,初步鉴定出金丝桃素、伪金丝桃素、原伪金丝桃素、绿原酸、芦丁、金丝桃苷、槲皮素等12...利用HPLC/DAD-ESI(-)MS联用技术对植物长萼小连翘(Hypericum erectum subsp. longisepalum L. H. Wu et D. P. Yang)中主要化学成分进行了分离分析,初步鉴定出金丝桃素、伪金丝桃素、原伪金丝桃素、绿原酸、芦丁、金丝桃苷、槲皮素等12种黄酮类、酚酸类和金丝桃素类等化学成分。展开更多
Using over 3 500 first P arrival times recorded by nine digital seismic stations from Hainan Digital Seismic Net-work during 1999～2005,a 3-D P-wave velocity model of the crust under Hainan Island and adjacent regions...Using over 3 500 first P arrival times recorded by nine digital seismic stations from Hainan Digital Seismic Net-work during 1999～2005,a 3-D P-wave velocity model of the crust under Hainan Island and adjacent regions has been determined. The results show that the pattern of velocity anomalies in the shallower upper crust is somewhat associated with the surface geological tectonics in the region. A relative low-velocity anomaly appears north of the Wangwu-Wenjiao fault zone and a relative high-velocity anomaly appears south of the Wangwu-Wenjiao fault zone,corresponding to the depressed areas in north Hainan Island,where many volcanoes are frequently active and geothermal values are relatively higher,and the uplifted and stable regions in central and south of the Hainan Is-land. In the middle and lower crust velocities are relatively lower in east Hainan than those in west Hainan,possi-bly suggesting the existence of the upwelling of hot materials from the mantle in east Hainan. The pattern of veloc-ity anomalies also indicates that NW faults,i.e.,the Puqian-Qinglan fault,may be shallower,while the E-W Wangwu-Wenjiao fault may be deeper,which perhaps extends down to Moho depth or deeper.展开更多
文摘Developing highly efficient platinum‐group‐metal‐free electrocatalysts towards hydrogen oxidation reaction(HOR)under alkaline electrolyte is critical for the development of alkaline exchange member fuel cells.Herein,we reported the synthesis of boron doped Ni electrocatalyst(B‐Ni/C)and its remarkable alkaline HOR performance,with a 10‐fold mass activity enhancement compared with that of undoped Ni catalyst.Experimental results and density functional theory calculations indicate the d‐p hybridization between the p orbital of B and the d orbital of Ni via B‐doping could lead to promoted OH adsorption and optimized hydrogen binding energy on Ni surface,which together with the reduced formation energy of water species,contributes to the enhanced HOR performance under alkaline electrolyte.
基金Key Project Process Mechanism and Prediction of Geological Hazards (2001CB711005-1-3) and State Key Basic Research Project Mechanism and Prediction of Continental Earthquakes (G1998040702). sponsored by the Ministry of Science and Techno
文摘利用HPLC/DAD-ESI(-)MS联用技术对植物长萼小连翘(Hypericum erectum subsp. longisepalum L. H. Wu et D. P. Yang)中主要化学成分进行了分离分析,初步鉴定出金丝桃素、伪金丝桃素、原伪金丝桃素、绿原酸、芦丁、金丝桃苷、槲皮素等12种黄酮类、酚酸类和金丝桃素类等化学成分。
基金The special project of Detection of Haikou City Earthquake Active Faults from the Tenth Five-year Plan of China Earthquake Administration (0106512)Joint Seismological Science Foundation of China (105086)CAS Key Laboratory of Marginal Sea Geology (MSGL0503).
文摘Using over 3 500 first P arrival times recorded by nine digital seismic stations from Hainan Digital Seismic Net-work during 1999～2005,a 3-D P-wave velocity model of the crust under Hainan Island and adjacent regions has been determined. The results show that the pattern of velocity anomalies in the shallower upper crust is somewhat associated with the surface geological tectonics in the region. A relative low-velocity anomaly appears north of the Wangwu-Wenjiao fault zone and a relative high-velocity anomaly appears south of the Wangwu-Wenjiao fault zone,corresponding to the depressed areas in north Hainan Island,where many volcanoes are frequently active and geothermal values are relatively higher,and the uplifted and stable regions in central and south of the Hainan Is-land. In the middle and lower crust velocities are relatively lower in east Hainan than those in west Hainan,possi-bly suggesting the existence of the upwelling of hot materials from the mantle in east Hainan. The pattern of veloc-ity anomalies also indicates that NW faults,i.e.,the Puqian-Qinglan fault,may be shallower,while the E-W Wangwu-Wenjiao fault may be deeper,which perhaps extends down to Moho depth or deeper.
