Time-dependent QM/EM Simulation Method Applied to Carbon Nanotube

2018 ◽  
Author(s):  
Qingqing Yang ◽  
Aiqiang Cheng ◽  
Hui Zeng ◽  
Dazhi Ding ◽  
Rushan Chen
Keyword(s):  
Carbon Nanotube ◽  
Simulation Method ◽  
Time Dependent ◽  
Em Simulation

The RC Analogy Provides a Versatile Computational Tool for Unsteady, Unidirectional Heat Conduction in Regular Solid Bodies Cooled by Adjoining Fluids

2003 ◽  
Vol 31 (3) ◽  
pp. 233-244
Author(s):  
Antonio Campo ◽  
Francisco Alhama
Keyword(s):  
Heat Transfer ◽  
Initial Conditions ◽  
Simulation Method ◽  
Heat Fluxes ◽  
Total Heat ◽  
Time Dependent ◽  
Total Heat Transfer ◽  
Transfer Rates ◽  
Electric Circuits ◽  
Spatio Temporal

Evaluation of spatio-temporal temperatures and total heat transfer rates in simple bodies (large plate, long cylinder and sphere) has been traditionally explained in undergraduate courses of heat transfer by the Heisler/Gröber or by the Boelter/Gröber charts. These three charts pose some restrictions with respect to the applicable times. Additionally, the charts do not provide information about the time-dependent heat fluxes at the surface. Conversely, evaluation of spatio-temporal temperatures, time-dependent heat fluxes at the surface and total heat transfer rates can be easily done for the entire time domain with the network simulation method (NSM) in conjunction with the commercial code PSPICE. NSM relies on the existing physical analogy between the unsteady transport of electric current and the unsteady transport of unidirectional heat by conduction. This analogy has been named the RC analogy in the specialized literature. The code PSPICE simulates the electric circuits for a specific body together with the imposed boundary and initial conditions, and produces numerical results for the quantities of interest, such as: the spatio-temporal temperature distributions; the time-dependent heat flux distributions at the surface; and the total heat transfer.

Time-Dependent Current Distributions of a Two-Terminal Carbon Nanotube-Based Electronic Device

2011 ◽  
Vol 115 (18) ◽  
pp. 5519-5525 ◽  
Author(s):  
Shizheng Wen ◽  
SiuKong Koo ◽  
ChiYung Yam ◽  
Xiao Zheng ◽  
YiJing Yan ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Electronic Device ◽  
Time Dependent ◽  
Current Distributions

scholarly journals Carbon nanotube uptake changes the biomechanical properties of human lung epithelial cells in a time-dependent manner

2015 ◽  
Vol 3 (19) ◽  
pp. 3983-3992 ◽  
Author(s):  
Chenbo Dong ◽  
Reem Eldawud ◽  
Linda M. Sargent ◽  
Michael L. Kashon ◽  
David Lowry ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Exposure Duration ◽  
Human Lung ◽  
Biomechanical Properties ◽  
Engineered Nanomaterials ◽  
Lung Epithelial Cells ◽  
Time Dependent ◽  
Dependent Manner ◽  
Lung Epithelial ◽  
Human Lung Epithelial Cells

The toxicity of engineered nanomaterials in biological systems depends on both the nanomaterial properties and the exposure duration.

Variance Reduction in Particle Methods for Solving the Boltzmann Equation

2006 ◽  
Author(s):  
Lowell L. Baker ◽  
Nicolas G. Hadjiconstantinou
Keyword(s):  
Boltzmann Equation ◽  
Shear Flow ◽  
Variance Reduction ◽  
Simulation Method ◽  
Reduction Technique ◽  
Particle Simulation ◽  
Time Dependent ◽  
Particle Methods ◽  
The Boltzmann Equation ◽  
Particle Simulation Method

We present a new particle scheme for solving the Boltzmann equation; this scheme incorporates a recently developed variance reduction technique discussed in [L. L. Baker and N. G. Hadjiconstantinou, Physics of Fluids, vol. 17, art. no 051703, 2005] which exhibits a significant computational efficiency advantage for low speed flows, compared to traditional particle methods. This paper describes how this variance reduction approach, achieved by simulating only the deviation from equilibrium, can be implemented as a particle simulation method. The new scheme is validated using time dependent shear flow calculations.

scholarly journals A first-principles simulation method for ultra-fast nano-optics

2019 ◽  
Vol 205 ◽  
pp. 04023 ◽  
Author(s):  
Mitsuharu Uemoto ◽  
Kazuhiro Yabana ◽  
Shunsuke A. Sato ◽  
Yuta Hirokawa ◽  
Taisuke Boku
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Light Propagation ◽  
Nonlinear Effects ◽  
Simulation Method ◽  
Time Dependent ◽  
Full Account ◽  
Nano Structure ◽  
Sham Equation ◽  
Ultrashort Laser

We develop a computational approach for ultrafast nano-optics based on first-principles time-dependent density functional theory. Solving Maxwell equations for light propagation and time-dependent Kohn-Sham equation for electron dynamics simultaneously, intense and ultrashort laser pulse interaction with a dielectric nano-structure is described taking full account of nonlinear effects. As an illustrative example, irradiation of a pulsed light on silicon nano-sphere system is presented.

Simulation of Structural Evolution Using Time-Dependent Density-Functional Based Tight-Binding Method

2020 ◽  
Vol 20 (11) ◽  
pp. 7206-7209
Author(s):  
Seung Mi Lee ◽  
Thomas A. Niehaus
Keyword(s):  
Density Functional ◽  
High Efficiency ◽  
Tight Binding ◽  
Computational Cost ◽  
Structural Evolution ◽  
Simulation Method ◽  
Time Dependent ◽  
Excitation Energies ◽  
Carbon Chains ◽  
Experimental Values

A faster and more efficient quantum mechanical simulation method for application to complicated issues of real systems beyond model cases has long been sought after. The density-functional based tight-binding (DFTB) method has successfully explained the atomistic and electronic properties of semiconductors, surfaces, and nanostructures. In addition, the time-dependent formalism implemented in DFTB showed high efficiency in terms of computational cost. In this study, we demonstrated the structural and electronic evolution of small molecules induced by a laser pulse using the time-dependent DFTB (TD-DFTB) method. We identified the critical fluence of the input laser for structural dissociations in carbon chains and fullerenes, which related to the structural stability. The excitation energies of several molecules calculated by TD-DFTB agreed with the experimental values.

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