1,494 research outputs found
Thermal Conductance for Single Wall Carbon Nanotubes
We report a theoretical analysis of the phonon thermal conductance, \kappa
(T), for single wall carbon nanotubes (SWCN). In a range of low temperatues up
to 100K, \kappa (T) of perfect SWCN is found to increase with temperature,
approximately, in a parabolic fashion. This is qualitatively consistent with
recent experimental measurements where the tube-tube interactions are
negligibly weak. When the carbon-carbon bond length is slightly varied, \kappa
(T) is found to be qualitatively unaltered which implies that the anharmonic
effect does not change the qualitative behavior of \kappa (T).Comment: Revtex, 4 figure
Dynamic stability of electrostatic torsional actuators with van der Waals effect
AbstractThe influence of van der Waals (vdW) force on the stability of electrostatic torsional nano-electro-mechanical systems (NEMS) actuators is analyzed in the paper. The dependence of the critical tilting angle and voltage is investigated on the sizes of structure with the consideration of vdW effects. The pull-in phenomenon without the electrostatic torque is studied, and a critical pull-in gap is derived. A dimensionless equation of motion is presented, and the qualitative analysis of it shows that the equilibrium points of the corresponding autonomous system include center points, stable focus points, and unstable saddle points. The Hopf bifurcation points and fork bifurcation points also exist in the system. The phase portraits connecting these equilibrium points exhibit periodic orbits, heteroclinic orbits, as well as homoclinic orbits
Single-walled carbon nanotube bundle under hydrostatic pressure studied by the first-principles calculations
The structural, electronic, optical and vibrational properties of the
collapsed (10,10) single-walled carbon nanotube bundle under hydrostatic
pressure have been studied by the first-principles calculations. Some features
are observed in the present study: First, a collapsed structure is found, which
is distinct from both of the herringbone and parallel structures obtained
previously. Secondly, a pseudo-gap induced by the collapse appears along the
symmetry axis \textit{X}. Thirdly, the relative orientation between
the collapsed tubes has an important effect on their electronic, optical and
vibrational properties, which provides an efficient experimental method to
distinguish unambiguously three different collapsed structures.Comment: 14 pages, 6 figure
TetraÂkis[1-phenyl-3-(1H-1,2,4-triazol-1-yl-κN 4)propan-1-one]bisÂ(thioÂcyanato-κN)manganese(II)
In the mononuclear title complex, [Mn(NCS)2(C11H11N3O)4], the MnII atom, lying on an inversion center, is coordinated by two monodentate thioÂcyanate anions and four monodentate 1-phenyl-3-(1H-1,2,4-triazol-1-yl)propan-1-one ligands in a distorted octaÂhedral geometry. Each complex molÂecule is linked to four neighboring ones by weak C—H⋯N and C—H⋯S hydrogen bonds, forming a two-dimensional sheet parallel to (001)
Searching for dark matter via mono- boson production at the ILC
High energy colliders provide a new unique way to determine the microscopic
properties of the dark matter (DM). Weakly interacting massive particles
(WIMPs) are widely considered as one of the best DM candidates. It is usually
assumed that the WIMP couples to the SM sector through its interactions with
quarks and leptons. In this paper, we investigate the DM pair production
associated with a boson in an effective field theory framework at the
International Linear Collider (ILC), which can be used to study the
interactions between the DM and leptons. For illustrative purposes, we present
the integrated and differential cross sections for the process, where the boson is radiated from the initial
state electron or positron. Meanwhile, we analyze the neutrino pair production
in association with a boson as the SM background.Comment: 12 pages, 5 figure
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