figurine coffee armchair chair art object

We investigate the band-gap modiication by collapsing deformation in C, BN, and BC3 nanotubes through rst-principles pseudopotential calculations. Semiconductor-metal transitions occur when zigzag C and armchair BC3 nanotubes undergo collapsing deformation, while in zigzag BN tubes, a variation of band gaps from 5 to 2 eV is found. On the other hand, the band gaps of armchair BN and zigzag BC3 ...

Graphene nanoribbon (GNR) with free edges can exhibit non-flat morphologies due to preexisting edge stress. Using molecular dynamics (MD) simulations, we investigate the freeedge effect on the shape transition in GNRs with different edge types, including regular (armchair and zigzag), armchair terminated with hydrogen and reconstructed armchair. The results show that initial edge stress and ene...

Phosphorene has been rediscovered recently, establishing itself as one of the most promising two-dimensional group-V elemental monolayers with direct band gap, high carrier mobility, and anisotropic electronic properties. In this paper, surface buckling and its effect on its electronic properties are investigated by using molecular dynamics simulations together with density functional theory ca...

Equilibrium molecular dynamics simulations show that graphene nanoribbons (GNRs) with zigzag edges have higher thermal conductivity (j) than armchair-edged ones, and the difference diminishes with increasing temperature or ribbon width. The dominant phonon wavelength for thermal transport can be much longer (by orders of magnitude) than the difference between the “roughness” of smooth zigzag an...

We have investigated the electronic structure and carrier mobility of armchair and zigzag single-walled MoS₂ nanotubes using density functional theory combined with Boltzmann transport method with relaxation time approximation. It is shown that armchair nanotubes are indirect bandgap semiconductors, while zigzag nanotubes are direct ones. The band gaps of single-walled MoS₂ nanotubes are along ...

Computer simulation of long missions in space can provide experience and predictions without the expense and risk of actual flights. Simulations are most helpful if they can model the behavior of key psychological factors of the crew over time, rather than simply predicting overall mission success. Because of the lack of experience with interplanetary trips and the problems of generalizing and ...

In a recent paper, Michael Otsuka and Alex Voorhoeve present a novel argument against prioritarianism. The argument takes its starting point from empirical surveys on people’s preferences in health care resource allocation problems. In this paper, I Vrst question whether the empirical Vndings support their argument, and then I make some general points about the use of “empirical ethics” in ethi...

Metallic single-walled carbon nanotubes have been proposed to be good one-dimensional conductors. However, the finite curvature of the graphene sheet that forms the nanotubes and the broken symmetry due to the local environment may modify their electronic properties. We used low-temperature atomically resolved scanning tunneling microscopy to investigate zigzag and armchair nanotubes, both thou...