Institution
Oak Ridge National Laboratory
Facility•Oak Ridge, Tennessee, United States•
About: Oak Ridge National Laboratory is a facility organization based out in Oak Ridge, Tennessee, United States. It is known for research contribution in the topics: Neutron & Ion. The organization has 31868 authors who have published 73724 publications receiving 2633689 citations. The organization is also known as: ORNL.
Topics: Neutron, Ion, Scattering, Neutron scattering, Microstructure
Papers published on a yearly basis
Papers
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TL;DR: Density functional theory calculations show that the high catalytic activity correlates with the partially vacant 5d orbitals of the positively charged, high-valent Pt atoms, which help to reduce both the CO adsorption energy and the activation barriers for CO oxidation.
Abstract: Platinum-based heterogeneous catalysts are critical to many important commercial chemical processes, but their efficiency is extremely low on a per metal atom basis, because only the surface active-site atoms are used. Catalysts with single-atom dispersions are thus highly desirable to maximize atom efficiency, but making them is challenging. Here we report the synthesis of a single-atom catalyst that consists of only isolated single Pt atoms anchored to the surfaces of iron oxide nanocrystallites. This single-atom catalyst has extremely high atom efficiency and shows excellent stability and high activity for both CO oxidation and preferential oxidation of CO in H-2. Density functional theory calculations show that the high catalytic activity correlates with the partially vacant 5d orbitals of the positively charged, high-valent Pt atoms, which help to reduce both the CO adsorption energy and the activation barriers for CO oxidation.
4,446 citations
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TL;DR: Larger numbers of species are probably needed to reduce temporal variability in ecosystem processes in changing environments and to determine how biodiversity dynamics, ecosystem processes, and abiotic factors interact.
Abstract: The ecological consequences of biodiversity loss have aroused considerable interest and controversy during the past decade. Major advances have been made in describing the relationship between species diversity and ecosystem processes, in identifying functionally important species, and in revealing underlying mechanisms. There is, however, uncertainty as to how results obtained in recent experiments scale up to landscape and regional levels and generalize across ecosystem types and processes. Larger numbers of species are probably needed to reduce temporal variability in ecosystem processes in changing environments. A major future challenge is to determine how biodiversity dynamics, ecosystem processes, and abiotic factors interact.
4,070 citations
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University of Tennessee1, Oak Ridge National Laboratory2, West Virginia University3, Umeå University4, University of British Columbia5, United States Department of Energy6, Ghent University7, Swedish University of Agricultural Sciences8, Institut national de la recherche agronomique9, Virginia Tech10, Michigan Technological University11, University of Toronto12, Pennsylvania State University13, University of Provence14, University of Georgia15, University of Florida16, University of California, Berkeley17, Lawrence Berkeley National Laboratory18, University of Arizona19, Purdue University20, Stanford University21, United States Department of Agriculture22, University of Helsinki23, University of Turku24, Massachusetts Institute of Technology25, University of Tennessee Health Science Center26, University of Tübingen27
TL;DR: The draft genome of the black cottonwood tree, Populus trichocarpa, has been reported in this paper, with more than 45,000 putative protein-coding genes identified.
Abstract: We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of duplicated genes from that event survived in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication, and gross chromosomal rearrangement appear to proceed substantially more slowly in Populus than in Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average from 1.4 to 1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with lignocellulosic wall biosynthesis, meristem development, disease resistance, and metabolite transport.
4,025 citations
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TL;DR: This Review summarize recent advances in the synthesis and characterization of C-dots and speculate on their future and discuss potential developments for their use in energy conversion/storage, bioimaging, drug delivery, sensors, diagnostics, and composites.
Abstract: Similar to its popular older cousins the fullerene, the carbon nanotube, and graphene, the latest form of nanocarbon, the carbon nanodot, is inspiring intensive research efforts in its own right. These surface-passivated carbonaceous quantum dots, so-called C-dots, combine several favorable attributes of traditional semiconductor-based quantum dots (namely, size- and wavelength-dependent luminescence emission, resistance to photobleaching, ease of bioconjugation) without incurring the burden of intrinsic toxicity or elemental scarcity and without the need for stringent, intricate, tedious, costly, or inefficient preparation steps. C-dots can be produced inexpensively and on a large scale (frequently using a one-step pathway and potentially from biomass waste-derived sources) by many approaches, ranging from simple candle burning to in situ dehydration reactions to laser ablation methods. In this Review, we summarize recent advances in the synthesis and characterization of C-dots. We also speculate on their future and discuss potential developments for their use in energy conversion/storage, bioimaging, drug delivery, sensors, diagnostics, and composites.
3,991 citations
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TL;DR: It is shown that inversion symmetry breaking together with spin-orbit coupling leads to coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides, making possible controls ofspin and valley in these 2D materials.
Abstract: We show that inversion symmetry breaking together with spin-orbit coupling leads to coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides, making possible controls of spin and valley in these 2D materials The spin-valley coupling at the valence-band edges suppresses spin and valley relaxation, as flip of each index alone is forbidden by the valley-contrasting spin splitting Valley Hall and spin Hall effects coexist in both electron-doped and hole-doped systems Optical interband transitions have frequency-dependent polarization selection rules which allow selective photoexcitation of carriers with various combination of valley and spin indices Photoinduced spin Hall and valley Hall effects can generate long lived spin and valley accumulations on sample boundaries The physics discussed here provides a route towards the integration of valleytronics and spintronics in multivalley materials with strong spin-orbit coupling and inversion symmetry breaking
3,986 citations
Authors
Showing all 32112 results
Name | H-index | Papers | Citations |
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Zhong Lin Wang | 245 | 2529 | 259003 |
Hyun-Chul Kim | 176 | 4076 | 183227 |
Bradley Cox | 169 | 2150 | 156200 |
Charles M. Lieber | 165 | 521 | 132811 |
Wei Li | 158 | 1855 | 124748 |
Joseph Jankovic | 153 | 1146 | 93840 |
James M. Tiedje | 150 | 688 | 102287 |
Peter Lang | 140 | 1136 | 98592 |
Andrew G. Clark | 140 | 823 | 123333 |
Josh Moss | 139 | 1019 | 89255 |
Robert H. Purcell | 139 | 666 | 70366 |
Ad Bax | 138 | 486 | 97112 |
George C. Schatz | 137 | 1155 | 94910 |
Daniel Thomas | 134 | 846 | 84224 |
Jerry M. Melillo | 134 | 383 | 68894 |