利用Monte-Carlo模拟研究了全局耦合网络上扩散限制的不可逆聚集-湮没过程的动力学行为. 在系统中, 同种类集团相遇, 将发生聚集反应; 不同种类的集团相遇, 则发生部分湮没反应. 模拟结果表明:1) 当两种粒子初始浓度相等时, 系统长时间演化后, 集团浓度c(t)和粒子浓度g(t)呈现幂律形式, c(t)～t^{- α}和g(t)～t^-β, 其中幂指数α和β满足α=2β的关系, 且α=2/(2 + q); 集团大小分布随时间的演化满足标度律, a_k(t)=k^-τt^-ωΦ(k/t^z), 其中τ≈-1.27q, ω≈(3 + 1.27q)/(2 + q), z=α/2=1/(2 + q); 2) 当两种粒子初始浓度不相等时, 系统经长时间演化后, 初始浓度较小的种类完全湮没, 而初始浓度较大的那个种类的集团浓度c_A(t)仍具有幂律形式, c_A(t)～t^-α, 其中α=1/(1+q), 其集团大小分布随时间的演化也满足标度律, 标度指数为τ≈-1.27q, ω≈(2 + 1.27q)/(1 + q)和z=α=1/(1 + q). 模拟结果与已报道的理论分析结果相符得很好.

Kinetics of diffusion-limited aggregation-annihilation process on globally coupled networks is investigated by the Monte Carlo simulation. In the system, when two clusters of the same species meet at the same node, they will aggregate and form a larger one; while if two clusters of different species meet at the same node, they will annihilate each other. The simulation results show that, (i) if the two species have equal initial concentrations, the concentration of clusters c(t) and the concentration of particles g(t) follow power laws at large time, c(t)～t^-α and g(t)～t^-β, with the exponents α and β satisfying α=2β and α=2/(2 + q); meanwhile, the cluster size distribution can take the scaling form a_k(t)=k^-τt^-ωΦ(k/t^z), where τ≈-1.27q, ω≈(3 + 1.27q)/(2 + q) and z=α/2=1/(2 + q); (ii) if the two species have different initial concentrations, the cluster concentration of the heavy species c_A(t) follows the power law at large time, c_A (t)～t^-α, where α=1/(1 + q), and the cluster size distribution of the heavy species can obey the scaling law at large time, a_k(t)=k^-τt^-ω\varPhi (k/t^z), with the scaling exponents τ≈-1.27q, ω≈(2 + 1.27q)/(1 + q) and z=α=1/(1 + q). The simulation results accord well with the reported theoretic analyses.

国家自然科学基金(批准号:1175131,10775104,10875086,10305009)资助的课题.