نتایج جستجو برای: friction theory
تعداد نتایج: 813640 فیلتر نتایج به سال:
When a classical master equation (CME) is used to describe the nonadiabatic dynamics of a molecule at metal surfaces, we show that in the regime of reasonably strong molecule-metal couplings, the CME can be reduced to a Fokker-Planck equation with an explicit form of electronic friction. For a single metal substrate at thermal equilibrium, the electronic friction and random force satisfy the fl...
Many important processes in science involve the escape of a particle over a barrier. In this review, we report, extend, and interpret various theories of noiseactivated escape. We discuss the connection between many-body transition state theory and Kramers' original diffusive Brownian motion approach (both in oneand multidimensional potential fields) and emphasize the physical situation inheren...
Recent experiments have shown that, for several proteins, the dependence of folding and unfolding rates on solvent viscosity does not obey Kramers' theory. Such a departure from standard Kramers' behavior is often attributed to the existence of internal friction, related to the structure of a polypeptide chain. In this paper, we propose an entirely different mechanism leading to violation of Kr...
We determine time correlation functions and dynamic structure factors of the number and charge density of liquid water from molecular dynamics simulations. Using these correlation functions we consider dielectric friction and electro-acoustic coupling effects via linear response theory. From charge-charge correlations, the drag force on a moving point charge is derived and found to be maximal a...
This paper examines the normal force between two opposing polyelectrolyte brushes and the interpenetration of their chains that is responsible for sliding friction. It focuses on the special case of semi-dilute brushes in a salt-free theta solvent, for which Zhulina and Borisov (J. Chem. Phys. 107, 5952 (1997)) have derived analytical predictions using the classical strong-stretching theory (SS...
Internal friction and void ratio will change among granular particles under vibration, and the size of void ratio directly affects strength of granular media. To further study the effect of vibration parameters on granular mechanical properties, discrete element method is used to simulate particles motion in a vibrating rectangular case by PFC2D software and study the influence of vibration fre...
We consider finite systems of interacting Brownian particles including active friction in the framework of nonlinear dynamics and statistical/stochastic theory. First we study the statistical properties for 1−d systems of masses connected by Toda springs which are imbedded into a heat bath. Including negative friction we find N + 1 attractors of motion including an attractor describing dissipat...
In the work presented here, a three-step identification procedure for rigid body dynamics, friction, and flexibilities, introduced in (Wernholt and Gunnarsson, 2005), will be utilized and extended. Using the procedure, the parameters can be identified only using motor measurements. In the first step, rigid body dynamics and friction will be identified using a separable least squares method, whe...
Using finite element method and multi-body dynamics method, this study established an engine digitalized virtual prototype embraced tribological characteristics in virtual prototype and MATLAB platform, and introduced Elastohydrodynamics theory into the system, wrote program with difference equation method, and solved the Reynolds Equation through shafting-bearing self-feedback control system, ...
The purpose of this paper is to study the modeling method for nonholonomic systems with friction by linear complementary problem (LCP). Firstly, the dynamic equation with multipliers for the nonholonomic system with friction is given. Secondly, a standard linear complementary model is established, which describes the normal and tangential characteristics for a nonholonomic system. Thirdly, by u...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید