Zhong Wei-Rong

Correlated Noises in a Prey–Predator Ecosystem

We investigate a Volterra ecosystem driven by correlated noises. The fluctuation in the death rate of the predator induces an increase of population density of the predators. The fluctuation in the growth rate of the prey, however, leads the predators to decay. It is reported that the predators undergo sensitivity to a random environment, whereas the preys exhibit a surprising endurance to the same stochastic factor. The predators are of better stability under strong correlation of noises.

Low Thermal Conductivity of Paperclip-Shaped Graphene Superlattice Nanoribbons

We design some graphene superlattice structures with ultra-low thermal conductivity 121 W/mK, which is only 6% of the straight graphene nanoribbons. The thermal conductivity of graphene superlattice nanoribbons (GSNRs) is investigated by using molecular dynamics simulations. It is reported that the thermal conductivity of graphene superlattice nanoribbons is significantly lower than that of the straight graphene nanoribbons (GNRs). Compared with the phonon spectra of straight GNRs, GSNRs have more forbidden bands. The overlap of phonon spectra between two supercells is shrinking.

Heat Transport in Double-Bond Linear Chains of Fullerenes*

Heat transport in one kind of double-bond linear chains of fullerenes (C60s) is investigated by the classical nonequilibrium molecular dynamics method. It is found that the negative differential thermal resistance (NDTR) is more likely to occur at larger temperature difference and shorter length. In addition, with the increase of the length, the thermal conductivity of the chains increases, and NDTR region shrinks and vanishes in the end. The temperature profiles reveal that a large temperature jump exists at a high-temperature boundary of the chains when NDTR occurs. These results may be helpful for designing thermal devices where low-dimensional C60 polymers can be used.

Denaturation of DNA Double-Helix Characterized by Thermal Conductance

We deal with the thermal conductance and the denaturation of a three-dimensional DNA double helix based on the Peyrard—Bishop—Dauxois model by using non-equilibrium molecular dynamics simulations. It is reported that the thermal conductance of DNA has a substantial decrease near the denaturation where the DNA double helix separates into two single chains. We explain this phenomenon through the phonon spectra at different temperatures. It is suggested that the denaturation of DNA can also be characterized by the change of the thermal conductance.

Synchronization in a Mutualism Ecosystem Induced by Noise Correlation

Understanding the cause of the synchronization of population evolution is an important issue for ecological improvement. Here we present a Lotka–Volterra-type model driven by two correlated environmental noises and show, via theoretical analysis and direct simulation, that noise correlation can induce a synchronization of the mutualists. The time series of mutual species exhibit a chaotic-like fluctuation, which is independent of the noise correlation, however, the chaotic fluctuation of mutual species ratio decreases with the noise correlation. A quantitative parameter defined for characterizing chaotic fluctuation provides a good approach to measure when the complete synchronization happens.