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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Experimental investigation of surfactant-enhanced ammonia-water absorption in a shell-and-tube absorber
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Core-shell rhodium sulfide catalyst for hydrogen evolution reaction / hydrogen oxidation reaction in hydrogen-bromine reversible fuel cell
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The effect of surface-bulk potential difference on the kinetics of intercalation in core-shell active cathode particles
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Core-shell structured Si/ZnO photovoltaics
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Enhancement of the oxygen reduction on nitride stabilized pt-M (M=Fe, Co, and Ni) core–shell nanoparticle electrocatalysts
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Core excitations across the neutron shell gap in 207 Tl
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Constraints on off-shell Higgs boson production and the Higgs boson total width in ZZ→4ℓ and ZZ→2ℓ2ν final states with the ATLAS detector
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K-shell transitions in L-shell ions with the EBIT calorimeter spectrometer
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A Near-Threshold Shape Resonance in the Valence-Shell Photoabsorption of Linear Alkynes
The room-temperature photoabsorption spectra of a number of linear alkynes with internal triple bonds (e.g., 2-butyne, 2-pentyne, and 2- and 3-hexyne) show similar resonances just above the lowest ionization threshold of the neutral molecules. These features result in a substantial enhancement of the photoabsorption cross sections relative to the cross sections of alkynes with terminal triple bonds (e.g., propyne, 1-butyne, 1-pentyne,...). Based on earlier work on 2-butyne [Xu et al., J. Chem. Phys. 2012, 136, 154303], these features are assigned to excitation from the neutral highest occupied molecular orbital (HOMO) to a shape resonance with g (l = 4) character and approximate pi symmetry. This generic behavior results from the similarity of the HOMOs in all internal alkynes, as well as the similarity of the corresponding g pi virtual orbital in the continuum. Theoretical calculations of the absorption spectrum above the ionization threshold for the 2- and 3-alkynes show the presence of a shape resonance when the coupling between the two degenerate or nearly degenerate pi channels is included, with a dominant contribution from l = 4. These calculations thus confirm the qualitative arguments for the importance of the l = 4 continuum near threshold for internal alkynes, which should also apply to other linear internal alkynes and alkynyl radicals. The 1-alkynes do not have such high partial waves present in the shape resonance. The lower l partial waves in these systems are consistent with the broader features observed in the corresponding spectra.
Strategies for Computer-Aided Discovery of Novel Open-Shell Polymers
Organic π-conjugated polymers with a triplet ground state have been the focus of recent research for their interesting and unique electronic properties, arising from the presence of the two unpaired electrons. These compounds are usually built from alternating electron-donating and electron-accepting monomer pairs which lower the HOMO–LUMO gap and yield a triplet state instead of the typical singlet ground state. In this paper, we use density functional theory calculations to explore the design rules that govern the creation of a ground-state triplet conjugated polymer and find that a small HOMO–LUMO gap in the singlet state is the best predictor for the existence of a triplet ground state, compared to previous use of a pro-quinoidal bonding character. Furthermore, this work can accelerate the discovery of new stable triplet materials by reducing the computational resources needed for electronic-state calculations and the number of potential candidates for synthesis.