scholarly journals Molecular Mechanism Research into the Replication Capability of Nanostructures Based on Rapid Heat Cycle Molding

2019 ◽  
Vol 9 (8) ◽  
pp. 1683 ◽  
Author(s):  
Meili Zhang ◽  
Yong Xin
Keyword(s):  
Brownian Motion ◽  
Binding Energy ◽  
Molecular Mechanism ◽  
Concentration Profile ◽  
Molecular Chain ◽  
Short Chain ◽  
Filling Rate ◽  
Packing Pressure ◽  
And Diffusion ◽  
Polymer Nanostructure

Aimed at the molding of polymer nanostructure parts, the interface model between long- and short-chain polycarbonates (PC) and nickel mold inserts was established by the molecular dynamics method. The molecular mechanism of the replication capability of polymer nanostructure part molding was discussed by analyzing the migration and diffusion of the molecular chain, concentration profile, filling morphology evolution, interface binding energy, and filling rate of conventional injection molding (CIM) and rapid heat cycle molding (RHCM). The results show that nanostructures are filled mainly during the packing stage. A short-chain PC system has a low glass transition temperature (Tg) and viscosity, good fluidity, and a high filling rate, so the replication capability of its nanostructures is good. A long-chain PC system has a fast cooling rate in CIM, its molecular chain motion is blocked, the filling rate is low, and the interface binding energy is small, and so its nanostructures have poor replication capability. However, the high temperature at the nanostructures can be maintained for a long time in RHCM, which promotes Brownian motion in the molecular chains. Under the action of packing pressure, molecular chains can overcome entanglement barriers and viscous resistance. Thus, the polymer concentration profile and filling rate increase with increasing packing pressure, which can produce more van der Waals energy. Furthermore, the evolution process of polymer filling morphology is realized by the Brownian motion of chain segments under packing pressure; that is, the diffusion motion of the molecular chain along the direction of a tube composed of other chains around it. With the increase of temperature or pressure, the migration and diffusion of the molecular chain can be promoted; thus, the replication capability of nanostructure parts for mold cavities can be enhanced.

A perfect probe: Resonance of underdamped scaled Brownian motion

2021 ◽  
Author(s):  
Yuhui Luo ◽  
Chunhua Zeng ◽  
Baowen Li
Keyword(s):  
Brownian Motion ◽  
Single Particle ◽  
Brownian Particle ◽  
Bistable System ◽  
Velocity Autocorrelation Function ◽  
Interacting Particles ◽  
Velocity Autocorrelation ◽  
Spectrum Density ◽  
Coupling Strengths ◽  
And Diffusion

Abstract We numerically investigate the resonance of the underdamped scaled Brownian motion in a bistable system for both cases of a single particle and interacting particles. Through the velocity autocorrelation function (VACF) and mean squared displacement (MSD) of a single particle, we find that for the steady state, diffusions are ballistic at short times and then become normal for most of parameter regimes. However, for certain parameter regimes, both VACF and MSD suggest that the transition between superdiffusion and subdiffusion takes place at intermediate times, and diffusion becomes normal at long times. Via the power spectrum density corresponding to the transitions, we find that there exists a nontrivial resonance. For interacting particles, we find that the interaction between the probe particle and other particles can lead to the resonance, too. Thus we theoretically propose the system with the Brownian particle as a probe, which can detect the temperature of the system and identify the number of the particles or the types of different coupling strengths in the system. The probe is potentially useful for detecting microscopic and nanometer-scale particles and for identifying cancer cells or healthy ones.

Comparative Studies on VS2 Bilayer and VS2/Graphene Heterostructure as the Anodes of Li Ion Battery

2021 ◽  
Vol 894 ◽  
pp. 61-66
Author(s):  
Rui Zhi Dong
Keyword(s):  
Binding Energy ◽  
Diffusion Barrier ◽  
First Principles ◽  
Electronic Devices ◽  
Lithium Ion ◽  
First Principles Calculations ◽  
Li Ion Batteries ◽  
Capacity Loss ◽  
Li Ion ◽  
And Diffusion

Due to the development of various mobile electronic devices, such as electric vehicles, rechargeable ion batteries are becoming more and more important. However, the current commercial lithium-ion batteries have obvious defects, including poor safety from Li dendrite and flammable electrolyte, quick capacity loss and low charging and discharging rate. It is very important to find a better two-dimensional material as the anode of the battery to recover the disadvantages. In this paper, first principles calculations are used to explore the performances of VS2 bilayer and VS2 / graphene heterostructure as the anodes of Li ion batteries. Based on the calculation of the valences, binding energy, intercalation voltage, charge transfer and diffusion barrier of Li, it is found that the latter can be used as a better anode material from the perspective of insertion voltage and binding energy. At the same time, the former one is better in terms of diffusion barrier. Our study provides a comprehensive understanding on VS2 based 2D anodes.

Correlated Brownian motion and diffusion of defects in spatially extended chaotic systems

2019 ◽  
Vol 29 (7) ◽  
pp. 071104 ◽  
Author(s):  
S. T. da Silva ◽  
T. L. Prado ◽  
S. R. Lopes ◽  
R. L. Viana
Keyword(s):  
Brownian Motion ◽  
Chaotic Systems ◽  
Spatially Extended ◽  
And Diffusion

scholarly journals Significance of Brownian Motion for Nanoparticle and Virus Capture in Nanocellulose-Based Filter Paper

Membranes ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 90 ◽  
Author(s):  
Olof Gustafsson ◽  
Simon Gustafsson ◽  
Levon Manukyan ◽  
Albert Mihranyan
Keyword(s):  
Brownian Motion ◽  
Filter Paper ◽  
Hydrodynamic Theory ◽  
Local Flow ◽  
Linear Flow ◽  
Virus Removal ◽  
And Diffusion ◽  
Poiseuille Equation ◽  
Linear Flow Velocity ◽  
Flow Velocities

Pressure-dependent breakthrough of nanobioparticles in filtration was observed and it was related to depend on both convective forces due to flow and diffusion as a result of Brownian motion. The aim of this work was to investigate the significance of Brownian motion on nanoparticle and virus capture in a nanocellulose-based virus removal filter paper through theoretical modeling and filtration experiments. Local flow velocities in the pores of the filter paper were modeled through two different approaches (i.e., with the Hagen–Poiseuille equation) and by evaluating the superficial linear flow velocity through the filter. Simulations by solving the Langevin equation for 5 nm gold particles and 28 nm ΦX174 bacteriophages showed that hydrodynamic constraint is favored for larger particles. Filtration of gold nanoparticles showed no difference in retention for the investigated fluxes, as predicted by the modeling of local flow velocities. Filtration of ΦX174 bacteriophages exhibited a higher retention at higher filtration pressure, which was predicted to some extent by the Hagen–Poiseuille equation but not by evaluation of the superficial linear velocity. In all, the hydrodynamic theory was shown able to explain some of the observations during filtration.

scholarly journals Quantum Brownian motion with inhomogeneous damping and diffusion

2015 ◽  
Vol 91 (3) ◽  
Author(s):  
Pietro Massignan ◽  
Aniello Lampo ◽  
Jan Wehr ◽  
Maciej Lewenstein
Keyword(s):  
Brownian Motion ◽  
Quantum Brownian Motion ◽  
And Diffusion

scholarly journals A DYNAMICAL APPROACH TO FRACTIONAL BROWNIAN MOTION

Fractals ◽  
1994 ◽  
Vol 02 (01) ◽  
pp. 81-94 ◽  
Author(s):  
RICCARDO MANNELLA ◽  
PAOLO GRIGOLINI ◽  
BRUCE J. WEST
Keyword(s):  
Dynamical System ◽  
Asymptotic Behavior ◽  
Brownian Motion ◽  
Correlation Function ◽  
Fractional Brownian Motion ◽  
Gaussian Processes ◽  
The Other ◽  
Hurst Coefficient ◽  
And Diffusion ◽  
Clear Relation

Herein we develop a dynamical foundation for fractional Brownian motion. A clear relation is established between the asymptotic behavior of the correlation function and diffusion in a dynamical system. Then, assuming that scaling is applicable, we establish a connection between diffusion (either standard or anomalous) and the dynamical indicator known as the Hurst coefficient. We argue on the basis of numerical simulations that although we have been able to prove scaling only for "Gaussian" processes, our conclusions may well apply to a wider class of systems. On the other hand, systems exist for which scaling might not hold, so we speculate on the possible consequences of the various relations derived in the paper on such systems.

Sign in / Sign up

Export Citation Format

Share Document