scholarly journals Polyamorphism and Two State Model in Liquid GeO\(_{2}\) under Compression: Insight from Visualization of Molecular Dynamics Data

2014 ◽  
Vol 24 (3S1) ◽  
pp. 95-98
Author(s):  
Nguyen Van Hong ◽  
Mai Thi Lan ◽  
Nguyen Thu Nhan
Keyword(s):  
Molecular Dynamics ◽  
Phase Region ◽  
High Density ◽  
State Model ◽  
Dynamics Simulation ◽  
Low Density ◽  
Wide Pressure Range ◽  
Simulation Results ◽  
Two State Model ◽  
Wide Pressure

The polyamorphism and two-state model based on the coordination number distribution in liquid GeO\(_{2}\) at 3200~K and in a wide pressure range are investigated by molecular dynamics simulation. Results show that the structure of liquid GeO\(_{2}\) mainly consists of GeO\(_{x}\) coordination units \((x=4,5,6)\) and OGe\(_{y}\) linkages \((y=2, 3)\). The distribution of OGe\(_{y}\) linkages in network structure is not uniform but tends to form clusters of OGe\(_{y}\). The cluster of OGe\(_{2}\) will form low-density phase region, conversely the cluster of OGe\(_{3}\) will form high-density phase region. In other word, under compression, in the liquid GeO\(_{2}\) coexist two states: low-density and high-density. The size of phase regions significantly depends on compression.

scholarly journals Molecular Dynamics Simulation of Grain Growth in Nanocrystalline Ni

2012 ◽  
Vol 715-716 ◽  
pp. 599-604 ◽  
Author(s):  
Stephen M. Foiles
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Grain Growth ◽  
High Density ◽  
Dynamics Simulation ◽  
Square Root ◽  
Twin Boundaries ◽  
Parabolic Kinetics ◽  
Simulation Results ◽  
The Creation

Grain growth in nanocrystalline Ni has been simulated by molecular dynamics. The simulations show the creation of a high density of twin boundaries during the growth as well as the formation of vacancies consistent with recent experimental observations. The growth follows parabolic kinetics with the diameter increasing with the square root of time consistent with behavior of conventional scale metals but in disagreement with prior simulation results.

The Study on Young's Modulus of Multilayered Cu/Ni Multilayered Nano Thin Films by Molecular Dynamics Simulation

2014 ◽  
Vol 513-517 ◽  
pp. 113-116
Author(s):  
Jen Ching Huang ◽  
Fu Jen Cheng ◽  
Chun Song Yang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Strain Rate ◽  
Young’S Modulus ◽  
Potential Function ◽  
Dynamics Simulation ◽  
System Temperature ◽  
Simulation Results

The Youngs modulus of multilayered nanothin films is an important property. This paper focused to investigate the Youngs Modulus of Multilayered Ni/Cu Multilayered nanoThin Films under different condition by Molecular Dynamics Simulation. The NVT ensemble and COMPASS potential function were employed in the simulation. The multilayered nanothin film contained the Ni and Cu thin films in sequence. From simulation results, it is found that the Youngs modulus of Cu/Ni multilayered nanothin film is different at different lattice orientations, temperatures and strain rate. After experiments, it can be found that the Youngs modulus of multilayered nanothin film in the plane (100) is highest. As thickness of the thin film and system temperature rises, Youngs modulus of multilayered nanothin film is reduced instead. And, the strain rate increases, the Youngs modulus of Cu/Ni multilayered nanothin film will also increase.

scholarly journals Unfolding mechanism of thrombin-binding aptamer revealed by molecular dynamics simulation and Markov State Model

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Xiaojun Zeng ◽  
Liyun Zhang ◽  
Xiuchan Xiao ◽  
Yuanyuan Jiang ◽  
Yanzhi Guo ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
State Model ◽  
Dynamics Simulation ◽  
Markov State Model ◽  
Markov State

scholarly journals Impact of Foreshock Transients on the Flank Magnetopause and Magnetosphere and the Ionosphere

2021 ◽  
Vol 8 ◽  
Author(s):  
Chih-Ping Wang ◽  
Xueyi Wang ◽  
Terry Z. Liu ◽  
Yu Lin
Keyword(s):  
Magnetic Field ◽  
3D Structure ◽  
Hybrid Simulation ◽  
High Density ◽  
Low Density ◽  
Simulation Results ◽  
Ground Magnetic ◽  
Pressure Perturbations

Mesoscale (on the scales of a few minutes and a few RE) magnetosheath and magnetopause perturbations driven by foreshock transients have been observed in the flank magnetotail. In this paper, we present the 3D global hybrid simulation results to show qualitatively the 3D structure of the flank magnetopause distortion caused by foreshock transients and its impacts on the tail magnetosphere and the ionosphere. Foreshock transient perturbations consist of a low-density core and high-density edge(s), thus, after they propagate into the magnetosheath, they result in magnetosheath pressure perturbations that distort magnetopause. The magnetopause is distorted locally outward (inward) in response to the dip (peak) of the magnetosheath pressure perturbations. As the magnetosheath perturbations propagate tailward, they continue to distort the flank magnetopause. This qualitative explains the transient appearance of the magnetosphere observed in the flank magnetosheath associated with foreshock transients. The 3D structure of the magnetosheath perturbations and the shape of the distorted magnetopause keep evolving as they propagate tailward. The transient distortion of the magnetopause generates compressional magnetic field perturbations within the magnetosphere. The magnetopause distortion also alters currents around the magnetopause, generating field-aligned currents (FACs) flowing in and out of the ionosphere. As the magnetopause distortion propagates tailward, it results in localized enhancements of FACs in the ionosphere that propagate anti-sunward. This qualitatively explains the observed anti-sunward propagation of the ground magnetic field perturbations associated with foreshock transients.

Molecular Dynamics Simulations on the Chain Fold During the Isothermal Orientation of n-Alkanes on Graphene

2021 ◽  
Author(s):  
Zhi Meng Zhang ◽  
Hua Yang ◽  
Jun Xia Shi ◽  
Jia Jun Wang ◽  
Zheng Guo Huang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Orientation ◽  
Dynamics Simulation ◽  
Ordered Structure ◽  
Graphene Surface ◽  
Parallel Orientation ◽  
Chain Folding ◽  
Hydrocarbon Chains ◽  
Simulation Results ◽  
Dynamics Simulations

Abstract The orientation of hydrocarbon chains plays a key role in the applications of organic materials. And chain folding in the process of molecular orientation is also of great significance for the design of organic molecular thin films. The effect of chain length and simulation temperature on the isothermal orientation of n-alkanes on graphene surface is studied by molecular dynamics simulation in this paper. And the chain folding is also described. The n-alkanes can form perpendicular ordered structure, parallel ordered structure or perpendicular orientation at relative low temperature and parallel orientation at relative high temperature on graphene surface. The chain fold happens when long n-alkanes form perpendicular ordered structure on graphene surface. And the simulation results show the interactions of n-alkane−graphene and n-alkane−n-alkane affect chain fold.

Analyzing the Effect of Node Density on the Performance of the LAR-1P Algorithm

2012 ◽  
Vol 7 (2) ◽  
pp. 16-29
Author(s):  
Hussein Al-Bahadili ◽  
Ali Maqousi ◽  
Reyadh S. Naoum
Keyword(s):  
Network Performance ◽  
Ad Hoc ◽  
High Density ◽  
Low Density ◽  
Probabilistic Algorithms ◽  
Excellent Performance ◽  
Node Density ◽  
Simulation Results ◽  
Mobile Ad Hoc ◽  
Hoc Networks

The location-aided routing scheme 1 (LAR-1) and probabilistic algorithms are combined together into a new algorithm for route discovery in mobile ad hoc networks (MANETs) called LAR-1P. Simulation results demonstrated that the LAR-1P algorithm reduces the number of retransmissions as compared to LAR-1 without sacrificing network reachability. Furthermore, on a sub-network (zone) scale, the algorithm provides an excellent performance in high-density zones, while in low-density zones; it preserves the performance of LAR-1. This paper provides a detailed analysis of the performance of the LAR-1P algorithm through various simulations, where the actual numerical values for the number of retransmissions and reachability in high- and low-density zones were computed to demonstrate the effectiveness and significance of the algorithm and how it provides better performance than LAR-1 in high-density zones. In addition, the effect of the total number of nodes on the average network performance is also investigated.

MD Analysis of Effect of Relative Humidity on Molecular Chain’s Network Structure of PEM

2016 ◽  
Vol 725 ◽  
pp. 238-242
Author(s):  
Isamu Riku ◽  
Keisuke Kawanishi ◽  
Koji Mimura
Keyword(s):  
Molecular Dynamics ◽  
Relative Humidity ◽  
Computational Model ◽  
Network Structure ◽  
Water Channel ◽  
High Density ◽  
Nafion Membrane ◽  
Water Molecules ◽  
Low Density ◽  
Density Of Water

To clarify the effect of relative humidity on molecular chain’s network structure, we at first employ Molecular Dynamics (MD) method to constitute the computational model for Nafion membrane, in which the water channel is artificially reproduced with an aggregation of water molecules. And then, relaxation calculation is performed and a relatively stable microstructure of Nafion membrane is derived. It is found that the regions of relatively low density of molecular chain’s network appear interchangeably together with those of relatively high density of water molecules.

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