arXiv subjects

Liqiu Wang

Publications and source records attributed to Liqiu Wang.

3 recordsLinked to original sources

arXiv2010

Transport Reversal in a Thermal Ratchet

Transport of a Brownian particle moving in a periodic potential is investigated in the presence of symmetric unbiased external force. The viscous medium is alternately in contact with the two heat reservoirs. We present the analytical expression of the net current at quasi-steady state limit. It is found that the competition of the asymmetric parameter of potential with the temperature difference leads to the phenomena like current reversal. The competition between the two driving factors is a necessary but not a sufficient condition for current reversals.

physics.bio-ph↗

arXiv2007

Flashing motor at high transition rate

The movement of a Brownian particle in a fluctuating two-state periodic potential is investigated. At high transition rate, we use a perturbation method to obtain the analytical solution of the model. It is found that the net current is a peaked function of thermal noise, barrier height and the fluctuation ratio between the two states. The thermal noise may facilitate the directed motion at a finite intensity. The asymmetry parameter of the potential is sensitive to the direction of the net current.

physics.bio-ph↗

arXiv2005

Heat Flow and Efficiency in a Microscopic Engine

We study the energestics of a thermal motor driven by temperature differences, which consists of Brownian particles moving in a sawtooth potential with an external load where the viscous medium is alternately in contact with hot and cold heat reservoir. The motor can work as a heat engine or a refrigerator under different conditions. The heat flow via both potential and kinetic energy are considered. The former is reversible when the engine works quasistatically and the latter is always irreversible. The efficiency of the heat engine (Coefficient Of Performance (COP) of a refrigerator) can never approach Carnot efficiency (COP).

physics.bio-ph↗