Each generation deals with big changes,but today's world is experiencing a perfect storm of seismic disruptions in the balance of power,a technological transformation,and a climate crisis.China is central to each ...Each generation deals with big changes,but today's world is experiencing a perfect storm of seismic disruptions in the balance of power,a technological transformation,and a climate crisis.China is central to each of these,and how the country manages its internal challenges will affect the people of China and the rest of the world.展开更多
Abattle is underway to determine which country will lead in the transition to zero-emission cars.The electric vehicle(EV)sector is expected to be a major pillar of the new green economy.Surprisingly,Germany,where the ...Abattle is underway to determine which country will lead in the transition to zero-emission cars.The electric vehicle(EV)sector is expected to be a major pillar of the new green economy.Surprisingly,Germany,where the petrolguzzling car was invented,is lagging.Meanwhile,China,where bicycles outnumbered cars just one generation ago,has become the world leader in EVs.展开更多
Oxygen reduction reaction(ORR)plays an important role in dictating the performance of various electrochemical energy technologies.As platinum nanoparticles have served as the catalysts of choice towards ORR,minimizing...Oxygen reduction reaction(ORR)plays an important role in dictating the performance of various electrochemical energy technologies.As platinum nanoparticles have served as the catalysts of choice towards ORR,minimizing the cost of the catalysts by diminishing the platinum nanoparticle size has become a critical route to advancing the technological development.Herein,first-principle calculations show that carbon-supported Pt9 clusters represent the threshold domain size,and the ORR activity can be significantly improved by doping of adjacent cobalt atoms.This is confirmed experimentally,where platinum and cobalt are dispersed in nitrogen-doped carbon nanowires in varied forms,single atoms,few-atom clusters,and nanoparticles,depending on the initial feeds.The sample consisting primarily of Pt_(2~7)clusters doped with atomic Co species exhibits the best mass activity among the series,with a current density of 4:16Amg^(-1)_(Pt)at+0.85V vs.RHE that is almost 50 times higher than that of commercial Pt/C.展开更多
Australia and China are strategic partners, with deeply integrated economies and growing people-to-people links.When there are differences,they are overcome with maturity and in the mutual interest of working together.
The year 2020 was a turning point in many ways. A pandemic tested our capacity for international cooperation. Our impact on the changing environment became more urgent.
文摘Each generation deals with big changes,but today's world is experiencing a perfect storm of seismic disruptions in the balance of power,a technological transformation,and a climate crisis.China is central to each of these,and how the country manages its internal challenges will affect the people of China and the rest of the world.
文摘Abattle is underway to determine which country will lead in the transition to zero-emission cars.The electric vehicle(EV)sector is expected to be a major pillar of the new green economy.Surprisingly,Germany,where the petrolguzzling car was invented,is lagging.Meanwhile,China,where bicycles outnumbered cars just one generation ago,has become the world leader in EVs.
基金This work was supported in part by the National Science Foundation(CHE-1900235 and CHE-2003685,S.C.)B.L.acknowledges support of a Chancellor’s Dissertation Year Fellowship from University of California,Santa Cruz and a Sigma Xi student grant-in-aid(G201903158663319)+8 种基金Y.P.acknowledges support of the National Science Foundation(DMR-1760260 and CHE-1904547)P.G.acknowledges support of the National Natural Science Foundation of China(51672007 and 11974023)the Key-Area Research and Development Program of Guangdong Province(2018B030327001 and 2018B010109009)This work partially used the Extreme Science and Engineering Discovery Environment(XSEDE)[64]which is supported by National Science Foundation grant number ACI-1548562the lux supercomputer at UC Santa Cruz,funded by NSF MRI grant AST 1828315the Nion U-HERMS200 microscope in the Electron Microscopy Laboratory(EML)of Peking UniversityThis research also used resources of the Advanced Photon Source,an Office of Science User Facility operated for the US Department of Energy(DOE)Office of Science by Argonne National Laboratory,and was supported by the US Department of Energy under contract No.DE-AC02-06CH11357 and the Canadian Light Source(CLS)and its funding partnersThe CLS is supported by the CFI,NSERC,National Research Council Canada,CIHR,the University of Saskatchewan,the Government of Saskatchewan,and Western Economic Diversification Canada.Part of the TEM and XPS work was performed at the Molecular Foundry and National Center for Electron Microscopy,Lawrence Berkeley National Laboratory,which is supported by the US DOE,as part of a user project。
文摘Oxygen reduction reaction(ORR)plays an important role in dictating the performance of various electrochemical energy technologies.As platinum nanoparticles have served as the catalysts of choice towards ORR,minimizing the cost of the catalysts by diminishing the platinum nanoparticle size has become a critical route to advancing the technological development.Herein,first-principle calculations show that carbon-supported Pt9 clusters represent the threshold domain size,and the ORR activity can be significantly improved by doping of adjacent cobalt atoms.This is confirmed experimentally,where platinum and cobalt are dispersed in nitrogen-doped carbon nanowires in varied forms,single atoms,few-atom clusters,and nanoparticles,depending on the initial feeds.The sample consisting primarily of Pt_(2~7)clusters doped with atomic Co species exhibits the best mass activity among the series,with a current density of 4:16Amg^(-1)_(Pt)at+0.85V vs.RHE that is almost 50 times higher than that of commercial Pt/C.
文摘Australia and China are strategic partners, with deeply integrated economies and growing people-to-people links.When there are differences,they are overcome with maturity and in the mutual interest of working together.
文摘The year 2020 was a turning point in many ways. A pandemic tested our capacity for international cooperation. Our impact on the changing environment became more urgent.
